Acid rain : rhetoric and reality [Online-ausg ed.] 9780415712767, 0415712769, 9781315883687, 1315883686, 0416921906, 0416922007

Table of contents :
Content: List of Tables
List of Figures
Acknowledgements
Preface
Part I: The Problem of Acid Rain 1. The Acid Rain Debate in Context 2. Sources, Patterns and Processes
Part II: The Science of Acid Rain 3. Scientific Complexities 4. Effects on Surface Waters 5. Effects on Soils and Vegetation 6. Effects on Buildings and Humans
Part III: The Technology of Acid Rain 7. Cures and Remedies
Part IV: The Politics of Acid Rain 8. International Concern and Initiatives 9. Acid Rain in the United States 10. Acid Rain in Britain
Bibliography
Index

Citation preview

ROUTLEDGE

Acid Rain Rhetoric and Reality

Chris C. Park

REVIVALS

Routledge Revivals

Acid Rain

This title, first published in 1987, provides an authoritative account of both the science and the politics o f acid rain. Chris Park places the debates sur­ rounding acid rain w ithin a global context, and examines the full im plications of scientific studies and the effects of acid rain on surface waters, soils and buildings. Evidence is draw n from around the w orld, including an examina­ tion o f the dam age in Scandinavia and G erm any and th e effects of acid rain in the U .K. and U.S.A. A comprehensive and relevant w ork, this is an im portant guide for students of geography, environm ent and sustainability and energy policy.

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Acid Rain R hetoric and Reality

Chris C. Park

M

, Routledge

jt. S m f j Taylor & Francis Group

First published in 1987 by M ethuen and Co. Ltd T his edition first published in 2013 by Routledge 2 Park Square, M ilton Park, A bingdon, Oxon, 0 X 1 4 4R N Simultaneously published in the USA and Canada by Routledge 711 T hird Avenue, N ew York, N Y 10017 Routledge is an imprint o f the Taylor & Francis Group, an informa business O 1987 Chris C. Park All rights reserved. N o part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, w ithout permission in w riting from the publishers. P u b lis h e r’s N o te T he publisher has gone to great lengths to ensure the quality o f this reprint b u t points out that some imperfections in the original copies may be apparent. D isclaim er T he publisher has made every effort to trace copyright holders and correspondence from those they have been unable to contact. A Library- of Congress record exists under LC control num ber: 87020398

ISBN 13: 978-0-415-71276-7 (hbk) ISBN 13: 978-1-315-88368-7 (ebk)

welcomes

ACID RAIN Rhetoric and reality

Chris C. Park

METHUEN London a n d N ew Y ork

For Angela, with love

First published in 1987 by M ethuen & Co. Ltd 11 New Fetter Lane, London EC'4P 4EE Published in the USA by M ethuen & Co. in association with M ethuen, Inc. 29 West 35th Street, New York NY l()(M)l © 1987 Chris C. Park Printed in G reat Britain by Richard Clay Ltd, Bungay, Suffolk

British Library Cataloguing in Publication Data

Park, Chris C. Acid rain: rhetoric and reality. 1. Acid rain-E nvironm ental aspects I. Title 363.7'386 T D I96.A 2 ISBN 0-416-92190-6 ISBN 0-416-92200-7 Pbk

Library o f C ongress Cataloging in P ublication Data

Park, Chris C. Acid rain. All rights reserved. No part of this book may be reprinted o r reproduced or utilized in any form or by any electro­ nic, mechanical or oth er m eans, now known o r hereafter invented, including photocopying and recording, or in any information storage o r retrieval system, without permission in writing from the publishers.

Bibliography: p. Includes index. 1. Acid rain------Environm ental aspects. I. Title. TD196.A25P36 1987 363.7'386 87-20398 ISBN 0-416-92190-6 ISBN 0-416-92200-7 (pbk.)

CONTENTS

List o f tables List offigures Acknowledgements Preface Part I

viii ix xi xii

THE PROBLEM OF ACID RAIN 1

2

T H E A CID RAIN D EB A TE IN CO N TEX T ‘Long to reign over us . . A cid rain as a pollutant The geography o f acid rain A cid rain in historic context Heritage o f interest Polarization o f views The debate opens Legislation - success or failure? Alarm bells ring in Britain Britain's invisible export A n international problem Conclusion SO U R C ES, PA TTERN S, AND PROCESSES T h e answer is blowing in the wind . . Acidity - definition and measurement Rainfall chemistry Acidification o f rainfall The acid rain cocktail Natural and man-made emissions o f S 0 2 and N O x Fossil fuels and oxide emissions Dispersion and transformation A cid deposition A cid surges

1 2 3 5 6 7 8 13 16 17 19 21 22 23 25 26 32 32 38 40 47 48

Part II

THE SCIENCE OF ACID RAIN SCIENTIFIC CO M PLEX ITIES Damage attributed to acid rain Buffer capacity and acidification Uncertainty and complexity Conclusion

53 53 58 62 67

EFFECTS ON SU RFA C E W A TERS ‘Down by the riverside . . Acidification o f surface waters Evidence o f recent changes Acidification processes Effects o f acidification on surface waters The heavy metal connection Conclusions

69

EFFECTS ON SOILS AND V EG E TA T IO N ‘D eep in the fo re s t. . Acidification o f soils Effects on vegetation Waldsterben - damage to West German forests Damage spreads Forest damage in Britain Complexity o f forest damage Crop damage Trees as pollution filters Conclusions

91

EFFECTS ON BU ILD IN G S A ND HUM ANS ‘Palaces and people . . Effects on materials and buildings Effects on human health Conclusion P art III

70 70 74 76 87 89

92 96 100 105 106 108 110 111 112 114 114 123 130

THE TECHNOLOGY OF ACID RAIN C U R ES AND R EM ED IE S ‘We have the technology . . Cure by buffering Prevention Conclusions

135 135 137 153

Part IV 8

9

THE POLITICS OF ACID RAIN IN T E R N A T IO N A L C O N C E R N A N D IN IT IA T IV E S T he acid rain storm . . . The debate opens - early milestones The gam e plan unfolds International initiatives Growing awareness and heated exchanges (1983) A ctions and decisions (1984) Enforcem ent and progress ( 1985) Conclusions A C ID R A IN IN T H E U N IT E D STA TES G ripes of w rath . . . Roots and routes Carter initiatives Reagan - the early years M ounting indecision (1983) Resistance and entrenchm ent (1984) Problem s at hom e and abroad (1985) M inor concessions (1986) Conclusion

10 A C ID R A IN IN B R IT A IN ‘N ot guilty, m ’L ord . . . The early debate The sum m er o f ’84 Select C om m ittee report Storm clouds gathering O fficial attitudes 1986 and all that Conclusions Bibliography Index

157 157 160 167 171 174 181 185 189 190 195 200 205 209 213 217 219 220 220 229 233 236 238 240 242 245 266

TABLES

1.1 E stim ated su lp h u r dioxide em issions in E u ro p e , 1973 2.1 Som e rep o rte d rainfall acidity values 2.2 E stim ated global em issions o f su lp h u r an d nitrogen oxides (in m illions o f to n n es p e r y ear) 2.3 E stim ated relative co n trib u tio n s to U K em issions o f various air p o llutants, 1980 4.1 A cidity o f river an d lake w aters in co u n tries o f th e w estern Pacific region 4.2 Source areas o f ions in lakes in G allow ay, south-w est Scotland 4.3 D eclining frog p o p u latio n in Lake T ra n v a tte n , S w eden, 1973-9 4.4 R ecord o f fish decline in L um sden L ak e, O n ta rio 5.1 S pread of forest dam age in F ed eral R epublic o f G erm an y , 1982-5 7.1 S ulphur co n ten t o f U nited K ingdom coal, 1982-3 8.1 C hanging estim ates o f sulphur em issions in E u ro p e , 1973-80 8.2 E stim ated rates o f em ission o f S 0 2 by co u n try , 1980 8.3 M ajo r im porters o f SC)2, 1980 8.4 C ountries th a t receive least S 0 2 from foreign sources, 1980 8.5 C om m itm en t o f co u n tries to the 1979 L R T A P C o n v en tio n , by start o f 1986 10.1 Som e effects o f acid rain on wildlife in th e UK

18 27 33 35 74 75 81 82 103 143 161 162 166 166 168 226

FIGURES

1.1 T he global n a tu re o f acid rain in th e early 1980s 1.2 C hanging levels o f sm oke em issions from coal com bustion in the U n ited K ingdom , 1960-82 1.3 S ulphur dioxide and sm oke co n cen tratio n s (annual averages) in central L o n d o n , 1962-83, an d estim ated su lp h u r dioxide co n centrations o v er th e w hole o f L ondon since 1580 1.4 Increasing levels o f w inter sunshine in the London area, 1950-82 1.5 S ulphur dioxide em issions from fuel com bustion in the U nited K ingdom , 1960-82 2.1 T he pH scale, with the pH o f som e com m on substances 2.2 Increase in acidity o f precip itatio n o ver th e E astern U n ited S tates, 1955-6 to 1972-3 2.3 V ariations in acidity o f precip itatio n over E u ro p e , 1974 2.4 D istribution o f m ean pH o f rain in S cotland, 1978-80 2.5 C hanging levels o f m an-m ade em issions o f sulphur dioxide in B ritain , 1900-82 2.6 Sim ple m odel of th e chem istry o f acid precip itatio n 2.7 Sim ple m odel o f dispersion and d eposition o f acid substances 3.1 Spatial coincidence o f acid rain , sensitivity, an d dam age in sou th ern N orw ay, early 1980s 3.2 D istribution o f dam age to lakes and forests in E u ro p e , early 1980s 3.3 A reas sensitive to fresh w ater acidification in E u ro p e , based on bedrock geology 4.1 D istribution o f acidified lakes in so u th ern N orw ay, w estern Sw eden, O n tario and alpine Italy 4.2 Increasing acidity o f lakes th rough tim e in so u th ern N orw ay, sou th ern S w eden, and the A diro n d ack M ountains (N o rth east U nited S tates) 4.3 C hanging to leran ce o f fresh w ater species as w ater pH falls 4.4 R ecent fall in p H o f Loch E n o ch , south-w est S cotland, inferred from diatom species in th e lake floor sedim ents 4.5 Som e biological changes in freshw ater lakes at low p H 4.6 D eclining fish p o p u latio n s in acidified lakes in so u th ern N orw ay

4 12

12 13 14 24 29 30 31 37 42 45 55 56 60 71

73 78 80 83 85

4.7 Loss o f brow n tro u t p o p u latio n from rivers in so u th ern N orw ay 4.8 Increase in alum inium co n cen tratio n s in acidified surface w aters in B elgium 5.1 T ypical stages in the dieback o f B ritish beech tre es 5.2 D eclining a nnual grow th-ring w idths in d am aged silver fir trees in the A lpirsbach forest district o f W est G erm an y , 1940-83 5.3 Initial grow th increase follow ed by slow er grow th rates in trees un d er acid d eposition 5.4 T ypical sym ptom s o f dam age in co niferous tre es su b ject to acid rain, with assum ed processes 5.5 R apid spread o f dam age to N orw ay spruce and silver fir trees in the B ad en -W iirttern b erg district o f W est G erm an y , 1980-4 5.6 E ffects o f acid rain on farm ing 7.1 M ain sources o f em issions o f su lp h u r dioxide and nitrogen oxides in the U n ited K ingdom , 1980 8 .1 E stim ated sulphur dioxide em issions in E u ro p e , 1980 8.2 E stim ated rates an d p a tte rn o f d eposition o f su lp h u r over E u r o p e ,1980 9.1 D om inant p atte rn s o f air flow across th e U n ited S tates 10.1 D eclining average w in ter sm oke levels in L o n d o n , 1921-71 10.2 T rajecto ries o f air m asses o ver W estern E u ro p e 10.3 N itrogen oxide em issions in th e U K , by source, 1972-82 10.4 C E G B pow er statio n s selected for fitting o f F G D eq u ip m en t to m eet the E E C D irective fo r a 60 p e r cent cut in S 0 2 em issions betw een 1980 and 1995

86 88 97 98 99 101 106 111 138 163 165 194 221 223 228

234

ACKNOWLEDGEMENTS

A nyone who has ever w ritten a book will know that when it is finished, the author swears never to write an o th er one! This is my fifth, and I would not have tackled it w ithout the support and encouragem ent o f people who mean a great deal to m e. Some of my partners in crim e in the D epartm ent of G eography at L ancaster University helped directly. Peter Mingins and Claire Jarvis of the C artographic U nit drew the figures; their skill in turning messy doodles into m inor works o f art is a constant source of pleasure. C lair G ould, form erly of the Physical G eography L aboratory, clarified som e of the science w here my understanding was minim al, and helped to check som e o f the references; h er quiet enthusiasm is much appreciated. My fellow academ ics in the d ep artm en t, as ever busy with their own research, kept out o f my way and provided a pleasantly quiet environm ent in which to work. W riting is a solitary pursuit, and my sanity and vanity were kept in check by my cherished circle of friends. Claire Jarvis, Philip and Gill G ow er, Peter-John and A nn D avies, and Robin and Jill Bundy helped in various ways to take my mind off acid rain and my hands off the w ord-processor; I really value their friendship. A ngela, my best friend and wife, witnessed my alternating phases of agony and ecstasy in writing the book, with custom ary calm ness. H er disarm ing indifference to things I find absorbing helps me to keep things in perspective. This book is an inadequate repaym ent for her honesty, love, and support.

PREFACE

A cid rain is now one o f the m ost serious enviro n m en tal p ro b lem s in developed countries. In terest in the problem has increased significantly w ithin th e last d ecad e, especially since rep o rts o f extensive forest dieback in W est G erm an y (even in areas co n sid ered to be u n p o llu ted ) sta rte d to a p p e a r in 1975. C oncern quickly sp read to S candinavia, w here large-scale fish d eath s w ere believed to be caused by acid rain, an d w here m ore recently concern has focused on forest changes and heavy m etal m obiliza­ tion in stream s, lakes, and g ro u n d w ater. A cid rain is widely believed to result from th e w ashout from the atm osphere o f oxides o f su lp h u r and nitrogen. A lthough these oxides exist n aturally in enviro n m en tal cycles and ultim ately have natural sources, th e m ain sources tod ay are coal-fired pow er statio n s and sm elters (which p roduce sulphur d ioxide, S 0 2) and m o to r vehicle exhausts (w hich p ro d u ce nitrogen oxides, N O x). These gaseous p o llu tan ts are light an d invisible, and they can be carried h u n d red s if not thousands o f kilo m etres by prevailing winds. T h e oxides m ay then mix with o th e r chem icals in the atm o sp h ere to produce th e poisonous an d corrosive substances th a t eith er settle as dry fallout o r are w ashed o u t by rain as acid d eposition. Em issions and fallout w ere previously extrem ely localized, but since th e introduction o f ‘tall stacks’ policies in b oth B ritain (since 1958) and the U nited S tates (since 1971)-p a ra d o x ic a lly to disperse p articu late p o llu tan ts and hence reduce local dam age - em issions a re now lifted into th e u p p e r air cu rren ts and carried long distances dow nw ind. T he tall stacks policies have thus tu rn ed a sm oke problem into an acid rain problem . N eith er w inds n o r acids respect political b o u n d aries, so the p o llu tan ts are often carried across state and national fro n tiers. A cid rain thus represents a hidden ex p o rt from o n e cou n try to a n o th e r - th e e x p o rte r gains through not having to install costly pollution-control e q u ip m en t o r constrain industrial activity to limit em issions, and th e im p o rter suffers from the adverse im pacts on its e n v iro n m en t (w ith none o f th e econom ic gains from th e pollution th at are e n jo y ed by th e e x p o rter, w hose air is purified in th e process). T hus acid rain is a critical problem for international relations, and it rightly claim s a high priority on th e ag en d a o f

Preface xiii political d eb ate both w ithin an d betw een co untries. It is as much a question of ethics as o f practice. T h e acid rain d eb ate now em b races m any w estern co u n tries - including C an ad a, the U n ited S tates, E n g lan d , S cotland, W ales, Sw eden, N orw ay, D en m ark , W est G erm a n y , th e N eth erlan d s, A u stria, Sw itzerland - and a grow ing num b er o f eastern co u n tries - including th e Soviet U n io n , P o lan d , E ast G erm an y , C zechoslovakia. A cid rain is believed to blow over Scandinavia and W est G erm an y from all o ver E u ro p e , but B ritain is often singled o ut as the largest single culprit (after the Soviet U n io n ). T he U nited N ations E n viron m en tal P rogram m e views acid rain as 'a p articu lar­ ly m o d ern , post-industrial form o f ruination [which] is as w idespread and careless o f its victim s an d o f in tern atio n al b o u n d aries as th e w ind that disperses it'. T he problem o f acid rain arises, strictly speak in g , n o t so m uch from the rainfall itself as from its effects on th e env iro n m en t. R u n o ff affects surface w ater (such as rivers and lakes) and g ro u n d w ater, as well as soils and vegetation. C onsequently changes in rainfall acidity can trigger off a range of im pacts on the chem istry an d ecology o f lakes and rivers (over 200 lakes in the A dirondack M o u n tain s o f N ew Y ork state are devoid o f fish), soil chem istry and processes (e.g. th e increased m obility o f toxic and p ersistent heavy m etals such as cadm ium ), th e h ealth and productivity of plants (including trees and crops; e.g. it is estim ated th at aro u n d on e-third o f W est G erm an y ’s forests a re now seriously affected by acid rain ), and building m aterials (including those o f historic and cu ltural im p o rtan ce, such as m any o f E n g lan d ’s finest c ath e d rals), and m etallic stru ctu res (such as New Y ork’s S tatu e o f L ib erty ). H um an h ealth m ight also be affected via the intake o f food and w ater co n tam in ated w ith toxic heavy m etals (e.g. cadm ium ) m obilized by fallout o f acid rain. T h e significance o f such im pacts is m ore th an purely scientific - they affect th e quality o f life for hum ans, they th reaten enviro n m en tal stability and the sustainability o f food and tim b er reserv es, an d they pose real econom ic p ro b lem s (e.g. in the cost o f rep air to buildings). A cid rain is th u s very m uch a hum an as well as a scientific p ro b lem , an d it has b ro ad econom ic, social, and m edical im plications. T he most suitable solutions to the p roblem s o f acid rain req u ire prevention ra th e r than cu re, and th e re is b ro ad ag reem en t in b oth th e political and scientific com m unities on the need to reduce em issions of sulphur and nitrogen oxides to th e atm o sp h ere . T he technology now exists to m ake this possible. H o w ev er, clean-up program m es will be expensive, and they m ight yield only qualified im provem ents. Inevitably th e high costs involved m ust be m et by th e co u n tries th at ex p o rt th e po llu tio n , w hereas the benefits to be gained will be e n jo y ed m ost by th e im p o rter countries. T hus arises the inevitable difference o f opinion betw een co untries o v er th e best way o f tackling th e p roblem o f acid rain. T hose countries th a t are h ard est hit by th e p roblem (such as C an ad a and the N ordic states) are convinced th at som ething m ust be d o n e, w ithout

xiv Preface fu rth er delay, to reduce em issions and th u s save th eir forests and lakes. W ith th e belief th at 'ch arity begins at h o m e ', som e tw enty-one g o v ern ­ m ents have now resolved to cut th eir ow n em issions o f su lp h u r dioxide by at least 30 p er cent (over 1980 levels) by 1993, and ho p e to p ersu ad e the m ain pro d u cers o f th e culprit oxides to jo in th em in a truly in tern atio n al attack on the pro b lem . T h e real villains o f th e piece, how ever, are th e U n ited S tates and G re at B ritain , w ho stub b o rn ly refuse to jo in this ‘30 p e r cent clu b ’ and rem ain reso lu te in th e ir belief th at th e problem is not yet sufficiently well u n d ersto o d to w arran t expensive investm ents which might at best yield only m in o r im p ro v em en ts in en v iro n m en tal quality. In D ecem b er 1984 th e U K P arliam en tary Select C om m ittee" on th e E nv iro n m en t re p o rte d on acid rain. It concluded th at B ritain is th e w orst air p o llu ter in W estern E u ro p e , and th a t it should tak e urgent action to reduce em issions o f su lp h u r and nitrogen oxides (m ainly from coal-fired p o w er stations). T h e B ritish g o v ern m en t, how ever, presen tly accepts the p roposed E u ro p ean em ission lim its as targets to aim for ra th e r th an obligations to fulfil. T h e internatio n al scientific com m unity regards acid rain as one o f th e m ost serious and significant en v iro n m en tal p roblem s o f o u r tim e, which req u ires urgent a tten tio n and im m ediate political initiatives b oth n ationally and internationally . L eading politicians and gov ern m en t officials in b oth B ritain and the U n ited S tates argue th at the pro b lem s are as yet to o little u n d ersto o d , and th at links with possible source areas an d likely sources (such as coal-fired po w er stations) are as yet to o ill defined to justify w holesale political in terv en tio n , which w ould req u ire th e in tro d u ctio n o f em ission controls an d lead to electricity price rises for th e consum er. A cen tral p art o f th e acid rain d e b ate th u s cen tres aro u n d the b alance b etw een scientific an d political arg u m en ts. O f p articu lar in terest are th e reasons given fo r reluctance o f the B ritish g o v ern m en t to co -o p erate w ith in tern atio n al initiatives designed to reduce em issions and elim in ate acid rain. T his attitu d e is u n p o p u lar am o n g o th e r m em b er states o f the E u ro p ean C om m unity, antagonistic to th e initiatives being fo rm u lated by th e Scandinavian c o u n tries, and - according to m any ex p erts - curiously at o dds w ith available evidence. T he acid rain d e b a te is thus as m uch a b attle in politics as a struggle in science.

Part I THE PROBLEM OF A C ID RAIN

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1 THE ACID RAIN DEBATE IN CONTEXT ‘Long to reign over u s ..

this m ost excellent can o p y , th e air, look you, this brave o ’erhanging firm am ent, this m ajestical ro o f frette d with golden fire, why, it ap p eareth nothing to m e b u t a foul and pestilen t congregation of vapours. (W illiam S h ak esp eare, H a m let, II, ii, 299) A cid rain has been called ‘an unseen plague o f th e industrial a g e ’ (A n o n 1984b: 6 ), and it is generally reg ard ed as one o f th e m ost serious environm ental problem s o f o u r tim es. A s an issue with b oth scientific and political dim ensions it ranks alongside im p o rtan t co n tem p o rary concerns like th e global increase o f carb o n dioxide in th e atm o sp h e re , th e sp read of toxic chem icals in the en v iro n m en t, and the possible environm ental consequences o f nuclear w ar. H ow ever, it p resen ts a som ew hat unique problem in th at its consequences are already ev id en t, its adverse effects are already d o cu m en ted , and its im pacts are very real to p eople living in affected areas (W helpdale 1983: 72). A cid rain is a w idesp read , serious, and costly p roblem th at will not simply fade aw ay in the public consciousness o r cease to create environm ental dam age. It has been blam ed fo r dam age to tree s in W est G erm an y , d eath o f fish in S candinavia, and o th e r unw anted effects (including dam age to buildings an d hum an h e alth ), and it th re a te n s intern atio n al relations b etw een th e U n ited S tates and C a n ad a , and betw een B ritain and h er E u ro p e an neighbours. T h e O rganization for E conom ic C o -o p eratio n and D ev elo p m en t (O E C D ) has estim ated th at acid rain costs the cou n tries o f th e E u ro p ean C om m unity £33-44 billion p er annum {The Tim es, 19 N ovem ber 1985, p. 16). T his book seeks to review th e m ain arg u m en ts curren tly being levelled in the ‘acid rain d e b a te ’. W e shall exam ine the general co ntex t o f acid rain in this ch ap te r, and th en progress to exam ine th e effects it is believed to have on lakes and rivers, fo rests and crops, h um ans and buildings (in P art II) and to explore possible solutions an d rem edies (in P art III). T he diplomatic and political ingredients of the debate are considered in Part IV. T h e term ‘acid ra in ’ refers to th e d ilute sulphuric an d nitric acids w hich.

2 Acid Rain m any believe, are created w hen fossil fuels are b u rn ed in p o w er statio n s, sm elters, and m o to r vehicles, and which fall o ver areas long distances dow nw ind o f possible sources o f the p o llu tan ts. F o r convenience th e term ‘acid ra in ’ will be used th ro u g h o u t this b o o k , although it has been dism issed as ‘em o tiv e’ and ‘in ad eq u ately n a m ed ' (co rresp o n d en ce by P rofessor B .A . T h ru sh to The T im es, 22 S ep tem b er 1984, p. 9). T h e term is a m isleading sh o rt-h an d version o f ‘acid p rec ip itatio n ', w hich includes the dry fallout o f oxides o f su lp h u r and nitrogen (in th e form o f dry gases and m inute aerosols, particles th a t rem ain su spended in th e a tm o sp h ere ) as well as w et deposition o f acids (in solution o r suspension in fog, o r on raindrops, snow flakes, o r hail). ‘A cid rain ’, as used h e re , includes b oth dry and w et deposition.

ACID RAIN AS A POLLUTANT P ollutants can be classified into tw o groups (P ark 1981: c h ap te r 7). F irst, th ere are m an-m ade m aterials (such as p ersistent synthetic chem icals like D D T ), which are not part o f natu ral en v iro n m en tal cycles and th ere fo re do n ot readily b reak dow n w hen released into th e en v iron m en t. A sub-set o f this g roup w ould include m aterials like n uclear w aste p ro d u cts th a t are strictly speaking - p arts o f n atu ral cycles, but th ese cycles o p e ra te extrem ely slowly o ver long tim e-spans. T he second g ro u p com prises m aterials th at already exist naturally in the e n v iro n m en t, and th a t n atural environm ental processes and cycles can cope with (o r n eu tralize), b reak dow n, disperse and recycle, but th at a p p e a r in m uch higher co n cen tratio n s than w ould norm ally be th e case. P ollutants o f this type are n o t necessarily harm ful in them selves - they create p roblem s only w hen th ey overlo ad n atural biogeochem ical cycles. A cid rain falls in this second g roup because its basic ingredients (su lp h u r dioxide, S 0 2, nitrogen oxides, N O x, and o zo n e, 0 3) do ap p e a r n aturally in the env iro n m en t, alb eit in sm aller co n cen tratio n s. In fact th e n atu ral acidity o f rainfall provides free supplies o f valuable n u trien ts for plant grow th. Som e a reas (even p arts o f S candinavia) with m ineral-deficient soils are happy to receive th e su lp h u r because o therw ise costly artificial fertilizers w ould be req u ired . It is th e increased acidity experien ced in recent years (w hich m any associate with air p o llution) th a t ap p e a rs to produce serious enviro n m en tal p ro b lem s, and which is th e tru e focus o f the acid rain d eb ate. A s a form o f po llu tio n , acid rain has som e unusual p ro p ertie s. It is invisible, with no discernible taste o r sm ell to hum ans. It has rem ain ed largely un d etected even in areas w here it has been falling for m any years, because its effects on th e en v iro n m en t are not readily noticeable in th eir early stages. It has no rap id , dram atic effects; it is a silent, creeping paralysis form o f cum ulative p o llu tan t. O nly in advanced cases a re its effects sufficiently qu an tifiab le to be convincing in any statistical sense (E ld e r 1983:58).

The acid rain debate in context 3 N eith er does acidification norm ally cause unsightly effects on th e landscape, o f the sort often associated with n u trien t en rich m en t (eutrop hication) with n itrate fertilizers w ashed from fields, w here enriched lakes are d rap ed with dense floating m ats o f algal bloom s. In fact, few w ho have w itnessed S candinavia’s acidic lakes fail to be m oved by th e a ir o f tranquillity offered by th e clear lakes, devoid o f sm ell o r floating v eg etation, with visibility increased considerably (th ro u g h loss o f aquatic life), an d lake beds covered by w hite acid -to leran t m osses. A cidified lakes are rem iniscent o f R achel C arso n 's Silent Spring (1962), in which birds and anim als died from the effects o f toxic pesticides and insecticides like D D T .

THE GEOGRAPHY OF ACID RAIN A cid rains and th e oxides th a t create them are blow n long distances by the w ind, often crossing seas an d n atio n al fro n tiers to becom e an invisible export. A s a result, the pollu ted is often far rem oved dow nw ind from the p olluter, w ho m ay rem ain unconvinced th a t a real problem exists. T he polluter may then raise serious and w ell-intentioned o b jectio n s to any rem edial m easures p ro p o sed by th e pollu ted th at w ould im pose a heavy cost on itself. A d d ed com plexity arises from the fact th a t, although su lp h u r and nitrogen oxides are now relatively ubiq u ito u s in industrial n atio n s, not all areas are affected by acid rain, and d ifferen t locations (even within an area) show different sym ptom s o f acidification. A s yet, the a reas w here acid rain im pacts are noticeable have been relatively few an d pred ictab le, given the ingredients o f th e ‘acid rain e q u a tio n ’. T he m ost seriously affected areas are show n in Figure 1.1. T hey ten d to have a n u m b er of properties in com m on (L a Bastille 1981:660): • they are co n cen trated in th e industrialized b elt o f th e n o rth ern hem isphere, dow nw ind o f dense co n cen tratio n s o f p o w er stations, sm elters, and large cities; • they are often uplan d o r m o u n tain o u s a reas, which are well w atered by rain and snow ; • being well w atered , they are o ften dissected by lakes an d stream s, and often covered by forest; and • being u p lan d , they o ften have thin soils and glaciated bedrock. M any p arts o f S candinavia, C anada and th e N o rth east U n ited S tates, and no rth ern E u ro p e (particularly W est G erm an y an d upland B ritain ) share these p ro p erties, and this is why they figure so p rom inently in th e acid rain d eb ate . A cross the A tlan tic th e re are a n u m b er o f ‘acid rain hot sp o ts’, including N ova Scotia, the C an ad ian Shield aro u n d so u th ern O n ta rio and Q u eb ec, the A diro n d ack M ountains, G re a t Sm oky M ountains, p arts of W isconsin and M inneso ta, the Pacific N orthw est U S A , th e C olo rad o R ockies, and the Pine B arren s o f N ew Jersey (L a B astille 1981). In co n trast, th ere are tw o types o f ‘safe a re a ’, w here acid rain is not a

Figure 1.1

Source:

T h e g l o b a l n a t u r e o f acid rain in th e e a r l y 1980s

estimated distribution of precipitation pH after Whelpdale (1983, Figure 1), isolated values after Galloway et al. (1982), areas where effects have been reported after Dudley, Barrett, and Baldock (1985, Figure 1).

The acid rain debate in context problem (at p resen t). O n e com prises those a reas th a t sim ply do n o t receive acid rain o r the gaseous oxides o f sulphur and n itro g en , because o f the fo rtunes o f location (aw ay from and not dow nw ind o f possible source areas). A lm ost all of th e so u th ern h em isp h ere , th e tropics and p arts o f the n o rth ern hem isphere are so p ro te c te d (up to now ). T he second group com prises areas th at receive acid p recipitation (w et o r dry) but can to le ra te it. M any areas have a n atu ral resistance (o r ‘buffering capacity’ - see ch ap te r 3) to acidification, w ith im m unity o ffered by alkaline soils o r lim estone b ed ro ck , which neutralize acid inputs. O th e r form s o f buffering are offered in the M idwest U n ited S tates, w here alkaline dust blow n from the w est neutralizes acid rain before it reaches th e gro u n d (L a Bastille 1981). A lkaline precip itatio n has been o bserved in Sw eden in th e past (pre-1960) in areas with lim estone o u tcrops an d areas w here cem ent was m anufactured (B a rre tt an d B rodin 1955).

ACID RAIN IN HISTORIC CONTEXT C oncern ov er acid rain m ay be a pro d u ct o f th e last d ecad e, b u t acid rain itself m ost certainly is not. It is very m uch a pro d u ct o f th e industrial age. A lthough a natural background level o f acid rain (derived from natural sources such as volcanic e ru p tio n s) has existed th ro u g h th e ages, it is only within the last 200 years th a t th e w idespread burning o f fossil fuels has led to a d ram atic (m an-m ad e) increase in em issions o f su lp h u r and nitrogen oxides, and a co rrespo n d in g increase in rainfall acidity. T h ere is evidence from m any a reas o f this association in tim e. Som e of the evidence reflects ecological changes triggered by acid precip itatio n in the past (w hich are described in g re a te r detail in ch ap te rs 4 an d 5). F or exam ple, th e bogm oss (S p hagnum sp p .) is very susceptible to S 0 2, and th ere are historic reco rd s o f its disap p earan ce from the P ennines at th e tim e o f the industrial revolution (T allis 1964; F erguson an d Lee 1983). R ecords o f changing diatom (m icroscopic m arine o r fresh w ater plants) p opulations, w hich reflect increasing acidity o f th e lake w aters during th e last tw o centuries, are preserved in lake sedim ents in som e Scottish lochs (in G allow ay, which presently receives acid rain) (B attarb e e an d Flow er 1982; Flow er and B a ttarb e e 1983; B attarb e e 1984; Flow er 1984; P en n in g ­ ton 1984; B attarb ee et al. 1985a, b). M any species o f lichen are also intolerant o f S 0 2, an d lichen d eserts a re com m on in and aro u n d urban and industrial areas in B ritain an d elsew here (G ilb ert 1975). O th e r evidence com es from studies o f changing p attern s o f rain w ater chem istry. D irect evidence o f a ten-fold increase in atm ospheric n itrate concentrations in N o rth A m erica and a five-fold increase in E u ro p e since the turn o f the century em erges in analyses o f records m ade by V ictorian scientists and k ep t at agricultural statio n s in E u ro p e an d N o rth A m erica (B rim blecom be an d S tedm an 1982). Indirect evidence is preserv ed in th e chem ical im purities locked up in th e unique archive o f p o lar snow and ice. A s each new snow lay er is in co rp o rated into th e ice, m aterial from th e

6 Acid Rain overlying air is trapped within it as both particles and gases (in air bubbles). The precise age of different levels within the ice can be determ ined scientifically, and so the polar ice caps contain an invaluable record of pollution spanning up to half a million years. R ecent analyses of ice cores from G reenland (W olff and Peel 1985; also The Tim es, 24 May 1986) indicate th at atm ospheric concentrations of sulphate and nitrate were variable but low before the turn o f the century (reflecting background levels of natural origin), but since 1900 they have increased exponentially nitrates have doubled and sulphates have trebled. A p art from providing a long record of changing air quality, these G reenland studies highlight the w idespread distribution of the oxides (which are dispersed by prevailing upper air winds). R ecent studies o f ice cores from the A ntarctic (W olff 1986), which confirm that there has been no detectable increase in sulphates and nitrates in that p art o f the southern hem isphere (rem ote from industry and emission sources of pollutants) over the last fifty years, provide an interesting and salutory contrast. T he evidence of association in time com plem ents the evidence of association in space betw een observed p attern s o f acid rain and m an-m ade em issions of S 0 2 and N O x. This does not in itself prove cause and effect, but the associations have clearly not arisen by chance.

HERITAGE OF INTEREST W idespread scientific interest has only started to focus on acid rain within the last decade. This reflects the growing seriousness of the problem and the related rise of acid rain as a political issue, but it is slightly surprising given over a century of research by scientists. T h ere are four leading figures in this intellectual dynasty (Cowling 1982; La Bastille 1981: 661-2). R o b ert A ngus Sm ith, an English chem ist who was B ritain ’s first Alkali Inspector (i.e. air pollution w atchdog), was the su b ject’s founding father. In 1852 Smith discovered a link betw een the sooty skies over industrial M anchester and the acidity he found in precipitation, and tw enty years later he used the term ‘acid rain’ in a 600-page book on the subject (Sm ith 1872; G orham 1982). Sm ith’s ideas w ere largely ignored until they inspired m ore detailed research on rainw ater quality and its control in the Lake D istrict in north-w est England during the late 1950s by D r Eville G o rh am , a C anadian ecologist (G orham 1955, 1958). By the mid-1960s early sym ptom s o f acidification were starting to appear in Scandinavia, and in 1967 the Swedish soil scientist Svente O den began a cam paign to inform the international scientific com m unity about acid rain, its assum ed causes, and its possible effects by speaking on it at scientific m eetings and writing about it in academ ic journals (O den 1976). O den widely regarded as the father of acid rain studies - envisaged a new form of ‘chemical w arfare’ in E u ro p e involving the effects of acid rain on surface w ater chem istry, fish populations, forest grow th, plant diseases, and accelerated dam age to buildings. His cam paign, pursued with m issionary

The acid rain debate in context 7 zeal, kindled an in terest in acid rain am ong rep u tab le scientists th at, although slow to sta rt, has accelerated since. Studies in th e U n ited S tates d a te back to 1963 (at least a decade before acid rain was to becom e a m ajo r issue in N orth A m erica), w hen D r G en e L ikens and D r F. H e rb e rt B o rm an n em b ark ed on a m ultidisciplinary study of a sm all w atershed w ithin th e H u b b ard B rook E xp erim en tal F orest in New H am pshire, which was to continue at least up to th e p resen t tim e. T heir study included th e chem istry o f rain w ater, and they found th a t highly acidic rains fell ov er th e a re a , although it was rem o te from possible local sources o f oxides (L ikens, B orm ann and Joh n so n 1972; L ikens et al. 1977). A cid rain is not sim ply an item o f scientific curiosity. It has becom e a m ajo r issue in in tern atio n al diplom acy. It was first raised as an in ter­ national issue by Sw eden at th e U n ited N ations C on feren ce on th e H um an E nvironm ent in S tockholm in 1972, and th rough th e next decade scientists and politicians in m any co u n tries started to realize th e possible scale and significance o f the p ro b lem . In tern ation al dialogue ab o u t acid rain has increased considerably since 1980, and it has becom e a key item on the agenda o f dom estic and in tern atio n al political d e b ate in E u ro p e , S candina­ via, C an ad a, and N orth A m erica. T h e so-called ‘acid rain d e b a te ’ is going on in B ritain an d th e U n ited S tates, and in m any o th e r developed countries. It will be exam ined in P art IV.

POLARIZATION OF VIEWS T here are two m ain schools o f tho u g h t in the d e b a te (B arab as 1983: 114). T h e m ajority o f scientists, and m any C anadian and E u ro p ean politicians, attrib u te visible dam age to lakes, forests, cro p s, and buildings to m an-m ade em issions o f sulphur dioxide ( S 0 2) and nitrogen oxides (NO*) from the burning o f fossil fuels (m ainly in conventional coal-fired pow er stations). In B ritain the scientists and politicians are jo in ed by a range of pressure groups (including F riends o f th e E a rth , G re en p e a c e, th e Ecology P arty , th e Socialist E nv iro n m en t and R esources A ssociation, and the Y oung L iberals Ecology G ro u p ) who have b an d ed to g e th e r to forw ard the ‘Stop A cid R ain U K ’ cam paign. T his unlikely and at tim es u n com fortable coalition d em ands th e intro d u ctio n o f rem edial m easures w ithout delay to significantly reduce em issions from chim neys and th u s p ro tect th e environm ent from fu rth e r dam age. A m inority o f scientists, and a caucus o f influential politicians in Prim e M inister T h a tc h e r’s C ab in et and President R eag an 's ad m in istratio n , are not convinced th at the case against m an-m ade oxide em issions is proven o r th a t costly em ission red u ctio n s im posed on industry w ould bring a b o u t the desired results. T hese dissenters are th erefo re resolutely o p p o sed to the adoption o f em ission control m easures, and rep eated ly call fo r m ore studies on the causes o f acid rain. T he relentless exchange o f acid rhetoric betw een these tw o schools has created a fascinating d e b ate com bining science, politics, and diplom acy in

8 Acid Rain B ritain (see ch ap te r 10) and elsew here (see ch ap ters 8 and 9). T h e d e b a te has c on tinued for o ver a decade and by th e late 1980s th e re are still no signs on the horizon o f any satisfactory (o r even h o n o rab le) reso lu tio n . T he d eb ate ranges far and w ide, although th ere is now little d o u b t th at the acidity o f rainfall in m any areas has increased in recen t years and continues to rise, and no d o u b t th a t m an-m ade em issions o f S 0 2 an d N O x can - if necessary - be red u ced (at a cost). H ow ever, th ere rem ain significant differences o f opinion on a n u m b er o f key areas, including: • the ex ten t to which m an-m ade em issions o f S 0 2 and N O x cause acid rain (i.e. m ight not n atural sources an d processes play a significant ro le?); • the ex ten t to which observed d am ag e to lakes and rivers, fo rests, cro p s, and buildings can be a ttrib u te d definitely to acid rain (i.e. are the inferred links real and causal, o r are o th e r - p erh ap s as yet h id d en o r unexplored - factors also involved?); • the ex ten t to which observed dam age is significant (i.e. is th e dam age serious enough to justify interv en tio n to reduce if not reverse it, and if recovery is possible how long might it tak e ? ); • th e extent to which p roposed red u ctio n s o f oxide em issions w ould be effective (i.e. w ould th ere be a p ro p o rtio n ate reduction in dam age to the en v iro n m en t?); and • the extent to which p roposed red u ctio n s o f oxide em issions w ould be cost-effective (i.e. w ould th e value o f th e b enefits - such as im proved forestry and fishing yields and less tangible b enefits like im proved environm ental quality - equal o r exceed the costs o f installing and running eq u ip m en t to reduce em issions from chim neys?). T hese differences o f opinion highlight th e com plexity o f th e acid rain d e b a te , because they all relate to relative q uestions to which th e re are no black and w hite answ ers. C o n seq u en tly , because each side in the d eb a te starts from differen t prem ises and is in pursuit o f d ifferen t goals (pro tectio n o f en v iro n m en t versus p ro tectio n of industry an d free en terp rise). It is extrem ely difficult for a com prom ise position to em erge. T h ere is only a w inner and a loser in th e d eb ate . In the final analysis, the en v iro n m en t - on which we d e p e n d fo r natural resources (such as fo o d , tim b er, an d m aterials) and intangibles like quality of life and scenic landscapes - will be th e w inner o r loser.

THE DEBATE OPENS B ritain has long claim ed to lead th e w orld in pollution co ntrol. T h e claim is n ot w ithout foundation in a country th at has p io n eered th e m o nitoring and control o f air and w ater p o llution, and th a t has a long and distinguished history o f effective enviro n m en tal legislation. B ut in th e p resen t in te rn a ­ tional d eb ate ov er acid rain, B ritain has elected to play a very differen t role

The acid rain debate in context 9 (outlined in detail in ch a p te r 10), alm ost diam etrical to its conventional trail-blazing stance. W hile m ost E u ro p ea n co u n tries are pressing a h ead w ith im p o rtan t initiatives designed to red u ce em issions o f su lp h u r dioxide an d n itrogen oxides (see ch ap te r 8) in an a ttem p t to reduce if not elim inate acid rains from th eir skies, B ritain chooses to ‘go it alo n e ’ and has ad o p te d an attitu d e o f inertia an d ap p a re n t lack o f concern th a t has p ro v ed frustrating to its E u ro p ean p a rtn e rs an d to m any scientists at hom e and ab ro a d . O n the o th e r side o f th e A tlan tic, C an ad a is follow ing th e E u ro p e a n lead in reducing em issions, while the U n ite d S tates plays th e B ritish gam e o f m aintaining a low profile an d p referrin g to ho p e th a t th e p ro b lem will soon becom e y esterday’s new s (see ch a p te r 9). T hose responsible fo r p ro tectin g B ritain’s en v iro n m en t have not been slow to point to past successes in dealing with pollution. M r M ichael H eseltine, then Secretary o f State for the E n v iro n m en t, told a U nited N ations E nvironm ent C o n feren ce held in L ondon in Ju n e 1982: I believe it is fair to claim th at genu in e, proven air pollution problem s have been less severe [in B ritain] in th e last ten years. I believe I can say w ith confidence th a t in th e U nited K ingdom , in o th e r co u n tries in E u ro p e , and I believe in N o rth A m erica, Jap an and m any o th e r industrialized states, th e rate o f progress is faster th an the rate of d eterio ratio n . I believe th at we are w inning. (T h e Tim es, 16 Ju n e 1982, p. 8) N ot everyone w ould share his optim ism , and th ere is a grow ing b elief th a t, although B ritain has won som e m inor skirm ishes, th e w ar is far from won. M oreover, policies and actions tak en to reduce ea rlier air pollution problem s are not u n related to p resent-day acid rain problem s. In fact with the benefit o f hindsight it a p p ears th at they have been prim e catalysts.

Britain’s grimy past In the past, air pollution was an extrem ely localized p ro b lem , cen tred m ainly on tow ns and cities. In the fo u rteen th cen tu ry , fo r exam ple, E dw ard I o rd ered a m an to be to rtu re d for burning coal and fouling L o n d o n ’s air (G o u d ie 1981:261). P roblem s o f air quality have becom e m uch m ore acute and m ore w idespread w ithin th e last 200 years, with rapid increases in the size o f u rb an a reas and th e sp read o f industrialization. B ritain was to lead th e w orld in industrial d ev elo p m en t, b u t th e toll for this was dark skies, grim y buildings, and an unhealthy urban populatio n - all b rought about by air p ollution from the burning o f fossil fuels. In the n in eteen th cen tu ry , m uch o f B ritain 's air was sm oky and acrid. T he n atio n 's industrial cities w ere th e dirtiest in the w orld, although most o f the countryside escaped th e w orst excesses o f grim e an d toxic gases. T he conditions in C arlyle’s ‘sooty M an ch ester’ (Briggs 1980: 93) are vividly captured in a contem po rary account o f the city given in 1835 by A lexis de

10 Acid Rain T ocqueville, a visiting F rench aristo crat, w ho saw a land ‘given o ver to industry’s use’, in which ‘huge palaces o f industry . . . k eep air and light o ut o f the hum an h ab itatio n s which they d o m in ate; they en velope th em in p erp etu al fog . . . a sort o f black sm oke covers the city. T he sun seen through it is a disc w ithout rays . . (H arv ie, M artin , and S charf 1981:40-1). W ell into the p resen t cen tu ry , th e trad itio n al heavy industrial cities o f B ritain - w orkhorses in th e n atio n ’s struggle to stay a h ead o f th e w orld econom ic pack - paid th e price for co n tin u ed reliance on fossil fuels in term s o f satanic enviro n m en ts. R onald K ershaw describes Sheffield in th e 1930s, w here ‘every sq u are foot o f exposed m asonry was black and filthy. T h e sun rarely p e n e tra te d a vast um brella o f sm oke and soot. C hildren w ere tak en away from the city for th e sake o f th eir h ealth . T h e re w ere thousands upon th o u san d s o f back to back houses. T h eir occupants w ere as grim and grim y as th e steelw orks from which they drew th eir su sten an ce’ (T h e Tim es, 19 D ecem b er 1981. p. 22). T his was the depressed baseline against which M r H eseltine drew his com parisons, and against which his o p p o n en ts clearly are w inning. T h ere are several landm arks in B ritain 's historic and p io n eerin g fight against air pollution. T he A lkali A ct o f 1863 tackled th e w orst types o f a ir po llu tio n , beginning with hydrochloric acid gas em issions from th e old alkali industry (D e p a rtm e n t o f E n v iro n m en t 1984:3). A m ajo r tu rning point was L o n d o n ’s infam ous ‘G re at Sm og’ o f 5 -9 D ecem b er 1952, th e best know n and m ost serious o f a long line o f ‘p e a-so u p ers’ th at had afflicted th e capital city since D ickensian tim es and been reco rd ed for p osterity in th e Sherlock H olm es stories. S u lp h u r dioxide gas com bined with sooty em issions from chim neys to form acid soot in the m oist air. T he sm og led to an estim ated 4,000 additional d e ath s from lung and h eart diseases, m ostly am ongst th e elderly and infirm , in the w eeks and m onths th at follow ed (R oyal C ollege o f Physicians 1970).

Tighter laws and clearer skies In the w ake o f the 1952 sm og, the go v ern m en t com m issioned th e B eaver C o m m ittee to ev alu ate levels and d eterm in e th e m ain sources o f air pollution and recom m end ap p ro p ria te controls. T he co m m ittee, w hose rep o rt was published in 1954, estim ated th a t air p ollution w as costing th e nation ov er £300 m illion p er year (at 1954 prices) and p ro p o sed th e central ingredients o f a pollution a b ate m en t policy, which w ere to be em b o d ied in legislation throu g h th e 1956 and 1968 C lean A ir A cts. T he C lean A ir A cts focused mainly on visible air p o llu tio n , in th e form of sm oke em issions co ntaining p articu late m aterial. T h e m ain aim was to cut soot em issions from chim neys and thus p rev en t th e form ation o f sm og particles. Invisible gaseous p o llu tan ts, such as su lp h u r dioxide, w ere alm ost com pletely o v erlo o k ed in th e A cts. T h e problem o f sm oke was

The acid rain debate in context tackled in various ways (D e p a rtm e n t o f E n v iro n m en t 1984: 3). T he g re ate r p a rt o f B ritain ’s sm oke had b een com ing from dom estic chim neys, an d this source w as reduced by enabling local a u th o rities to declare sm oke control zones, w ithin which the em ission o f sm oke from housing was b a n n e d , and to help people to pay fo r th e installation o f special g rates for burning sm okeless fuel. Pow er stations and industry had been em itting less sm oke th an houses, and the favoured solution was to rem ove larger particu late m aterial at source and build higher chim neys to release th e rem aining small particulates and gases higher in the atm o sp h ere w here diffusion and dispersion over a w ider area w ould be possible. Sm oke from lorries, buses, and o th e r diesel-engined vehicles has been reduced by setting tighter standards to be m et by m an u factu rers, and by enforcing b e tte r m ain te­ nance through annual inspections. Sm oke from the railways has been all but elim inated with th e dem ise o f th e ‘steam ag e' atte n d a n t upon the switch from coal-burning to electric and diesel pow er. It is im p o rtan t to stress th at these air pollution con tro l m easures w ere not designed to stop o r limit the production o f su lp h u r dioxide and nitrogen oxides; n o r did they. T he aim was to disperse th e gaseous em issions o ver a w ider area (thus diffuse and dilute them ). T hese pollution-control m easures, coupled with the switch from coal to cleaner, m ore convenient fuels (such as natural gas and oil), have led to a fall in sm oke em issions in th e U n ited K ingdom by over 85 p er cen t since 1958 (Figure 1.2) and b ro u g h t visible im provem ents in air quality over B ritain. T h e ‘tale o f th re e cities’ is now very d ifferent. R onald K ershaw claim s with pride th at Sheffield is now sm oke free an d ‘on e o f th e cleanest industrial cities in E u ro p e ’ {The T im es, 19 D ecem b er 1981, p. 22). C leaner air m eans m ore sunshine, and th e decline in sm oke co n cen tratio n s o ver central L ondon since 1960 (F igure 1.3) has brought an increase o f about 70 p er cent in the am o u n t o f w inter sunshine reco rd ed at the L ondon W eath er C entre in central L ond o n (F igure 1.4). O n an average w inter day, visibility in L ondon has m ore than do u b led . L on d o n ers are th ankful th a t thick, choking sm ogs are now a thing of the past. M an ch ester b oasts a 90 p er cent reduction o f w inter sm o k e, a doubling o f w in ter sunshine hours, a fall in sulphur dioxide levels by tw o-thirds, and a halving o f the bronchitis d eath rate since the mid-1950s {The T im es, 18 M arch 1980, p. 4). O x ford has also enjoyed a m ark ed d ro p in th e frequency o f fogs since th e mid-1960s, attrib u ted in p art to im plem en tatio n o f the 1956 C lean A ir A ct (G om ez and Sm ith 1984). Im provem ents have been seen in th e invisible p o llu tan ts as well. S ulphur dioxide em issions across the natio n have fallen by on e-th ird since 1970 (Figure 1.5), an d by up to a half in m any cities (including L o ndon) (D ep artm en t o f E nv iro n m en t 1984), m ainly b ecause o f declining o u tp u ts from dom estic, tran sp o rt, an d industrial sources. C learly not all o f th e im provem ent in air quality can be a ttrib u te d directly to th e effect of legislation, because o f th e delay in im provem ent ev id en t in m any areas;

Figure 1.2 C h an g in g levels o f sm o k e em issions from coal co m b u stio n in th e U n ite d K in g d o m , 1960-82

Source:

data from Department of Environment (1984)

Figure 1.3 S u lp h u r d ioxide an d sm o k e c o n c e n tra tio n s (an n u a l av erag es) in c en tral L o n d o n . 1962-83, a n d e stim a te d su lp h u r d ioxide c o n c e n tra tio n s o v e r th e w hole o f L o n d o n since 1580

Source: data for 1962-83 from G reater London Council (1985); data since 1580 from Brimblecombe (1977)

The acid rain debate in context Figure 1.4

Increasing levels of winter sunshine in the London area, 1950-82 Kew

1. 8

-

V § £

_m

;

London W eather Centre

co

D

o5

1.4

/

-

° X «3 S, Q *-) 0> (0 Q . S> 1. 0 -

Source:

I

---- 1----

1950

1960

1970

1980

d ata from D ep artm en t o f E nvironm ent (!9K4)

social as well as legislative factors are involved, along with th e changing industrial base and closure o r conversion o f public utilities. T h ere are m any signs o f im proving air quality in post-w ar B ritain, and in 1972 M r E ldon G riffiths (U n d er-S ecretary o f S tate at th e D ep artm en t of the E nvironm ent) could proudly claim th at B ritain leads th e industrial w orld in cleaning up its u rb an a ir’ ( The T im es, 21 A pril 1972). K enneth M ellanby has n oted how ‘in th e last 30 years o u r cities have all becom e much clean er, hum an health has im proved, plants flourish w here previous­ ly they d ied , and dam age to o u r buildings has been greatly red u ced ' (correspond ence to The T im es, 15 S ep tem b er 1984, p. 9). O ak tre e s, which are in to leran t o f sm oke and industrial fum es and had alm ost d isap p eared from L ondon since the industrial rev o lu tio n , could be p lan ted again in H yde P ark in 1978 (T h e T im es, 6 M arch 1978, p. 2). Even th rough the 1970s there was m ounting evidence o f declining air pollution in L ondon, with the gradual re tu rn o f lichen flora in w oodlands in the north and west of G re a te r L o n d o n , including som e species last seen th ere in 1800 (H aw ksw orth and R ose 1981), possibly reflecting the gradual decline o f sulphur dioxide concen tratio n s o v er the n a tio n ’s capital city (Figure 1.3).

LEGISLATION - SUCCESS OR FAILURE? In the light o f this ap p a re n t success story o f co ntrolling air p ollution and im proving B ritain’s air q uality, it is interesting to reflect on why attitu d es tow ards air pollution control in B ritain have a ltered so visibly, and to ask w hat is the connection with acid rain? Tw o key factors are intertw ined.

Figure 1.5

S u lp h u r dioxide em issions from fuel com bustion in th e U n ite d K in g d o m , 1960-82

Power stations Refineries Other industries Transport Commercial/ public services Agriculture Domestic

I

1

I

I

1

I

I

I

I

1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 Source:

data from D e p a rtm e n t of E nvironm ent (I984)

1

The acid rain debate in context Visible smoke and invisible gases The first key factor is m ounting concern over the invisible (i.e. gaseous) air pollutants, particularly sulphur dioxide ( S 0 2). D espite evidence o f a national fall in emissions (see Figure 1.5), and of im proved air quality at many city sites, there was growing anxiety am ongst inform ed observers during the 1970s that concentrations of S 0 2 from pow er stations and hom e heating systems, and carbon m onoxide from cars, w ere well above the limits in force in som e countries (G reater L ondon Council 1973). T he anxiety was fuelled partly by em erging evidence of dam age that appeared to stem from air pollution. For exam ple, som e well-established plant species that had flourished for nearly 300 years in L ondon's Chelsea Physic G arden (one of the oldest botanical gardens in the w orld) were showing signs of stress by 1976. The possible links betw een these observed effects and m easured levels of S 0 2 in the G arden (which proved to be three tim es higher than in industrial Teesside in north-east England) did not pass unnoticed ( The Tim es, 25 March 1976). In D ecem ber 1973 D r Basil B row n, Scientific A dviser to the G reater London Council (G L C ), had w arned that L ondon - which already had am ongst the highest S 0 2 levels in the country - faced the threat of increased pollution from S 0 2 em itted from new pow er stations planned for the capital over the next decade (G reater London Council 1973). Almost a decade later, in A ugust 1982, the Scientific Branch of the G L C was to report that central L ondon, which still suffered m ore S 0 2 pollution than any city in B ritain, was ‘nudging the limits set down by the E E C (G reater London Council 1982). M anchester’s A ssistant D irector of E nvironm ental H ealth expressed fears in March 1980 that the im provem ents in S 0 2 levels observed in recent years were unlikely to continue (in fact they might well d eterio rate) over the next decade, particularly in the city centre. His predictions were founded in the increasing tendency am ongst both industrialists and householders to return to coal as a source o f heating and energy in a financial clim ate of restraint and in the light of O P E C oil price increases (which were forcing oil users to turn to heavier grades with a higher sulphur content, or to switch to o th er fuels).

Tall stacks paradox The second critical factor, not unrelated to the first, was the tall chimneys (or stacks) policy introduced in the Clean A ir Acts. The new taller chimneys which discharge pollution high in the air, did im prove air quality locally by dispersing the pollutants over a w ider area. An ‘o ut o f sight, out of m ind’ attitude to air pollution control prevailed. D ilution was the solution to pollution, and the ‘air pollution problem ’ o f the day, defined on the basis of particulate m aterial, appeared to be solved. H ow ever, the ‘problem ’ was not solved - particularly for gaseous

16 Acid Rain pollutants - because w hat goes up must com e dow n, even if it is further afield. T he sulphur and nitrogen oxides released on burning fossil fuels can be carried hundreds if n ot thousands o f kilom etres by the w inds, and then fall (as wet o r dry acid precipitation) in rem ote areas far downwind from their point of origin. In essence, the gaseous pollutants are now being exported from urban and industrial centres to th e surrounding countryside and to distant areas downwind. This is the ‘tall stacks p arad o x ’ (Likens and B orm ann 1974) - the inadvertent replacem ent of an original visible, local air pollution problem (soot) with an invisible long-distance (even trans-frontier) problem (acid rain). T he sym ptom s o f the cure may turn o ut to be worse than the sym ptom s of the original malaise. Sim ilar explanations of the links betw een air pollution control initiatives and acid rain are offered in the U nited States, w here ‘well intentioned regulations may unwittingly have aggravated the problem ' (L a Bastille 1981:662). New rules introduced by the E nvironm ental Protection A gency (E P A ) in the 1970 US Clean A ir A ct caused industrial plants and pow er stations to increase the height of stacks, so that by 1981 th ere w ere 179 stacks at least 150 m etres high, of which 20 w ere as high as 300 m etres.

ALARM BELLS RING IN BRITAIN W hat had started out as essentially local air pollution problem s w ere being turned into regional problem s by the tall stacks policies. By the early 1970s, there were signs of declining interest in local sm oke problem s and growing interest in the b ro ad er distributions o f pollution, particularly from sulphur dioxide. In late July and A ugust 1972, for exam ple, 15.000 school children throughout Britain helped with an air pollution survey organized by the A dvisory C entre for E ducation (A C E ) and the Sunday Times ( The Times, 19 June 1972). T hey collected inform ation on the distribution o f selected species of lichen (which are sensitive to sulphur dioxide - see ch ap ter 5). T he lichens w ere used as a ‘doom w atch d ial’ of air pollution, and the aim was to build up a m ap of levels of pollution across the country. T he A C E survey produced alarm ing results (M abey 1974: 4). T he m ap th a t em erged show ed only four areas in Britain with pure air - H ad rian ’s W all, the Lake D istrict fells, E xm oor, and parts o f N orfolk. Particular ‘black spots’, or lichen deserts, were found in the T ham es Valley around L ondon, around B irm ingham , in the coalfield areas of W est Y orkshire, D u rh am , and N orthum berland, in parts of Scotland’s M idland V alley, and in South W ales. T hese results w ere all the m ore alarm ing because the badly polluted areas were alm ost identical to those nam ed by the B eaver C om m ittee nearly two decades (and two C lean A ir A cts) previously. Surveys by school children can be ignored by those who question the rigour and scientific objectivity o f th eir results. H ow ever, when the scientific ‘professionals’ e n te r the scene, results are m ore difficult to

The acid rain debate in context overlook. The regional extent o f S 0 2 pollution in Britain was unquestion­ ably dem onstrated, to even the most ardent sceptic, in studies o f rainfall acidity in Scotland by staff o f the Institute o f T errestrial Ecology (IT E ) published in mid-1982 (Fow ler et al. 1982). The IT E study show ed that rainfall acidity in parts o f Scotland was up to ten times higher than norm al background levels, and that acid rain was just as much o f a problem there as it was in parts o f Scandinavia and N orth A m erica - areas with an established history o f this form of pollution. T he worst-hit areas appeared to be along the west coast, north of G lasgow , up to the Isle of Skye. A lthough the survey found that industries in Glasgow ap p eared to produce up to one-third o f the acid rain th at fell locally, across Scotland as a whole the pollutants appeared to come from throughout th e U nited Kingdom and even from as far away as m ainland E urope. W ithin three m onths of the appearance o f the IT E results for Scotland, evidence em erged that acid rain was falling in the rest of B ritain. A report com m issioned by the D ep artm en t of the E nvironm ent (D oE ) and prepared by the U K Review G ro u p on A cid R ain, based at the governm ent’s W arren Spring L aboratory, concluded th at in som e parts of the U K the severity of the acid rain problem was ‘o f the sam e o rd er as in other high input areas of Scandinavia and N orth A m erica’ (1982).

BRITAIN’S INVISIBLE EXPORT The next link in the chain was the rising tide o f opinion th at argued that not only was B ritain fouling its own nest with acid rain, but it was exporting invisible oxides o f sulphur and nitrogen abroad. In 1971 the Swedish M inistry of Foreign A ffairs first accused its E uropean neighbours of unwittingly dum ping their noxious oxides downwind in Scandinavia (Royal Ministry of Foreign A ffairs 1971), and the accusations were repeated in 1972 when the Swedish governm ent proposed action to avert acid rain dam age to the U nited N ations Stockholm C onference. B ritain was singled out at the tim e as perhaps the largest single co ntributor to Sw eden’s acid rain problem , and the finger was pointed at the C entral Electricity G enerating B oard (C E G B ) as the prim ary culprit. D espite protestations from the C E G B (1979) that it was being wrongly accused - a storyline that was to continue up to the present day (see chapter 10) - the serious allegations w ere not w ithdrawn. By June 1976 Jim C allaghan’s L abour governm ent had to confess that sulphur dioxide discharged from pow er station chim neys in Britain was being deposited as acid rain over Norway and o th er parts of southern Scandinavia. This startling adm ission, which has never since been repeated in public - especially since M argaret T h atch er’s Conservative governm ent took office in May 1979 - appears in a report by the D o E ’s C entral U nit on E nvironm ental Pollution (D ep artm en t of E nvironm ent 1976). The report recognized that the C E G B ’s tall stacks policy had dispersed the pollution nuisance to the upper atm osphere but also allowed it to be carried to o th er

18 Acid Rain countries. This was to be the first of a long line of British reports (see chapter 10) to conclude that the precise effects o f acid rain on forest and freshw ater resources are not clear, and th at many topics need to be further investigated. T he D oE repo rt was a timely fo reru n n er of a m ore detailed scientific study o f sulphur dioxide pollution carried o ut by the O rganization for Econom ic C o-operation and D evelopm ent (O E C D ), which claim ed to give rough indications of the extent of the S 0 2 problem and was published in Paris in July 1977. Eleven countries participated in the five-year study (1972-6) - A ustria, Belgium , D enm ark, Finland, F rance, W est G erm any, the N etherlands, N orw ay, Sw eden, Sw itzerland, and the U nited K ingdom. T he O E C D survey established th at in the early 1970s the eleven countries betw een them w ere injecting around 9 million tonnes o f sulphate into the atm osphere each year, although the contributions varied considerably from country to country (Table 1.1). All countries received back on their own territories a fair proportion of what they sent up, but som e (especially D enm ark and the U nited Kingdom ) were net exporters whilst others (especially A ustria, F inland, N orw ay, Sw eden, and Sw itzerland) were net im porters. T he report concluded th a t th ere was strong evidence th at the sulphur dioxide pollution caused the acid rain and snow th at ap p eared to be killing salmon and tro u t, especially in Norway and Sweden but possibly also in Scotland. Britain was heavily im plicated in the O E C D rep o rt, being described as ‘most responsible for polluting E u ro p e ’s air with sulphuric fum es’ ( The Tim es, 13 July 1977, p. 7). The study found that Britain not only produced m ore sulphur pollution than any o th er E uropean nation, but m ore of it ended up in the skies above o th er countries. B ritain was producing around Table 1.1

Estimated sulphur dioxide emissions in Europe, 1973 Annual SO? emission

Country

Population (million)

Per inhabitant (kg)

National total (tonnes)

Austria Belgium Denmark West Germany Finland France Netherlands Norway Sweden Switzerland United Kingdom

7.4 9.6 5.0 61.2 4.7 49.5 13.2 3.9 7.9 6.2 54.2

29.6 51.7 62.2 32.1 58.3 32.7 29.5 23.5 52.0 12.1 51.7

221,000 499,000 312,000 1,964,000 274.000 1,616,000 391,000 91,000 415,000 76,000 2,803,000

Source: O rganization for Economic Co-operation and D evelopm ent (1977).

The acid rain debate in context 2.8 million tonnes of sulphuric pollutants p er year, whilst Norway - the country the worst affected by fallout - produced only 91,000 tonnes itself and received a further 60,000 tonnes from Britain. W hat at the time was referred to as ‘sulphur rain ’ was being seen as ‘one of B ritain’s least welcome invisible exports' ( The Times, 28 N ovem ber 1977, p. 2). Behind the scenes, governm ent scientists in Britain were starting to look carefully at the whole issue and politicians were beginning to realize the im plications (both dom estic and international) of the recent scientific findings. By the end o f 1977 biologists and chem ists from the C EG B were engaged in studies of sulphur dam age in Norway, in collaboration with scientists o f N orw ay’s Fish and Forests Project (correspondence from D r Peter C hester to The Times, 1 D ecem ber 1977, p. 19), although British critics suspected that the C E G B was ‘up to the classical ploy o f using a flurry of research into effects as a sm okescreen behind which causes continue u nabated’ (correspondence from Professor D. Bryce-Smith to The Tim es, 15 D ecem ber 1977, p. 26). The sam e accusation was to be repeatedly levelled against both the C EG B and the British governm ent over at least the next eight years (see chapter 10). Public interest in the ‘sulphur rain’ problem was also rising, and in late N ovem ber rep resen ta­ tives of 20,000 of B ritain’s youth visited the D oE and the C E G B to ask ihem to reduce sulphur emissions from British pow er stations and industry I The Times, 28 N ovem ber 1977, p. 2). By late 1977 Scandinavian concern over B ritain’s ap parent air o f calm over acid rain was m ounting. Sven Larsson o f Faltbiologerna (the Swedish Y outh Federation o f Field Biologists) was able to give an alarm ing inventory o f the problem in Sweden ( The Times, 28 N ovem ber 1977, p. 2) - 10 per cent of the country’s 100,000 lakes w ere already dam aged by acidification, fish could no longer survive in 2,300 lakes in Norway and Sw eden, Sweden claim ed to have lost around £5 million a year in forest production (and this could rise to £40 million by the year 2000), and the cost of corrosion in the country could be around £250 million by 1981. B ritain was starting to ap p ear as the sleeping giant in the tale, and the goodwill won in past successes in controlling air pollution was rapidly being eroded by the governm ent’s attitude of complacency.

AN INTERNATIONAL PROBLEM It is true that there are im mense difficulties in unequivocally establishing the links betw een cause and effect (e.g. that S 0 2 emissions do produce acid rain, and that acid rain does have the inferred effects on lakes, forests, crops, and buildings). Such difficulties are explored in chapter 3. H ow ever, geographical patterns are part o f ‘the acid test’, and these point quite clearly in a given direction. G ross p atterns provide a key. Since the mid-1960s, the area affected by acid rain in the N ortheast U nited States, in northern E uro p e, and in Scandinavia has m ore than tripled, and

20 Acid Rain these are th e regions m ost exposed to em issions o f su lp h u r and n itrogen oxides (B arab as 1983). M ore localized p a tte rn s reinforce th e pictu re. D ow nw ind, thou san d s o f tre e s are dying, and lakes an d stream s th a t once co n tained m any fish now co n tain few ; h u n d red s o f kilo m etres upw ind, factories and pow er statio n s th a t b u rn coal o r oil are em ittin g su lphurous gases high into th e atm o sp h e re , precisely because th ey can th en be carried long distances before they fall to th e gro u n d again (in d u st, rain , and snow ) ( The Tim es, 10 Jan u ary 1984, p. 2). G ra n te d th e co n n ectio n is m ainly one >f inference, b ut this is often all th a t is rev ealed in com plex enviro n m en tal problem s A n additional dim ension to th e acid rain problem in p art explains B ritain ’s reluctance to act on th e evidence available. It is clear th at acid rain has a truly tran s-n atio n al c h aracter, so th a t th e cost o f rem oving a source o f th e pollu tan ts (m ainly S 0 2 an d N O x) m ight well fall in one country while th e cost o f not rem oving it - o r, conversely, th e b enefits of rem oving it - m ay fall in on e o r m ore o th e r countries. C o n seq u en tly those cou n tries th at im port acid rain (A u stria , F in lan d , N orw ay, S w eden, and Sw itzerland in E u ro p e , and C a n ad a) have a stro n g er vested in te re st, and an attitu d e o f m uch g re a te r urgency, in ensuring th a t rem edial actions are tak en in those co u n tries th a t export it (D e n m a rk and th e U n ited K ingdom in E u ro p e , and th e U SA in N o rth A m erica). It is not necessarily in th e best econom ic in terest o f th e ex p o rters to tak e precip itate steps (such as the im position o f regulations o r em ission stan d ard s) th e econom ic and b ro ad e r benefits from which w ould pass m ainly to th e im porters. T his p olarization o f a ttitu d es is well illu strated in the reply o f M r P atrick Jen k in (th e then Secretary o f State for the E n v iro n m en t) to a charge o f com placency (in B ritain ’s a ttitu d e to a d raft E E C directive on S 0 2 ) m ade in th e H ouse of C om m ons on 8 F eb ru ary 1984. H e arg u ed th a t ‘th e G erm an G o v e rn m en t, which clearly feels a g rea ter n eed because o f th e problem o f th e effect on trees to m ove faster, is going ah ead ; b u t we shall need to discuss all this in th e context o f th e C o m m u n ity ’s d irectiv e’ ( The T im es, 9 F eb ru ary 1984, p. 4). T he events o f M onday, 18 M arch 1985, on both sides o f the A tlan tic, highlight the urgency and seriousness o f in tern atio n al concern over acid rain. In L o ndon , leaders o f en vironm ental groups from several E u ro p ean countries including W est G erm an y , the N eth erlan d s, S w eden, and A ustria m et M r W illiam W aldegrave (U n d er-S ecretary o f S tate at th e D ep a rtm e n t o f the E nvironm en t) to p ro test at the British g o v ern m en t's failure to curb acid rain ( The Tim es, 19 M arch 1985, p. 4). Feelings w ere running high th at B ritain had refused (an d con tin u es to refuse) to ratify a p ro p o sed E E C directive calling for a reduction o f 60 p er cen t in su lp h u r dioxide em issions and 40 p er cent in em issions o f nitrogen oxides by 1995, an d declined to jo in the so-called ‘30 p er cen t clu b ' - a group o f industrialized nations com m itted to reduce S 0 2 em issions from pow er statio n s and factory chim neys by 30 p e r cent w ithin th e next d ecad e. Som e 3,000 m iles aw ay in Q uebec C ity, C an a d a, th e C an ad ian prim e m inister (M r B rian M ulroney)

The acid rain debate in context was beginning a sum m it m eeting w ith A m erica's P resid en t R eag an . A cid rain - alleged to drift n orth-w est from A m erica’s m ain industrial belt and fall ov er C an ad a - was to p o f th e sum m it ag en d a, a h ead o f research into ‘S tar W ars’ technology an d th e testing o f cruise m issiles o ver C an ad a ( The Tim es, 19 M arch 1985, p. 5). T h e sam e m essages em erged from b oth m eetings - th e g overnm ent was reluctant to spend vast sum s o f m oney on large-scale clean ups, o r to jeo p ard ize anticip ated econom ic recovery by cracking dow n on industry, w ith o u t m uch stro n g er evidence to link acid rain to em issions o f S 0 2 and N O x, to link p roposed red u ctio n s in em issions with ex p ected im prove­ m ents in air (and rain) q uality, and to link the massive costs o f action with m easurable benefits (such as im provem ents in hum an health and e n v iro n ­ m ental quality, and/or increases in agricultural an d forestry productivity). B oth sets o f critics w ere told th a t m ore research on th e subject was req u ired b efore rem edial action was justified e ith e r as necessary o r likely to be effective (o r, m ore precisely, cost-effective).

CONCLUSION T he burning o f fossil fuels in pow er stations, industry, and m o to r vehicles app ears to be turning S h ak e sp e a re ’s ‘m ajestical ro o f' into a ‘foul and pestilent congregation o f v ap o u rs’, m ore com m only referred to as acid rain. H aving set th e acid rain into context, we tu rn next (in ch a p te r 2) to a m ore detailed tre a tm e n t o f th e processes believed to be involved in creating, dispersing, and depositing th e acid p ollutants.

2 SOURCES, PATTERNS, AND PROCESSES ‘The answer is blowing in the wind’

O clouds, unfold! (W illiam B lak e, M ilto n , p reface) T h e acid rain d e b ate is com plex and fo u n d ed on m any unresolved scientific puzzles. T h ere are tw o key a reas o f uncertainty. O n e is th e link betw een possible sources o f su lp h u r and nitrogen oxides (especially m an-m ade ones) and the pro d u ctio n o f acid rain. T h e o th e r is th e link b etw een acid rain and dam age to the en v iro n m en t. U nless these links are established to an ex ten t and in a way th at is convincing - particularly to politicians, th e electricity generatin g utilities, and g o vernm ent scientists - it will be extrem ely difficult to persu ad e th em th a t expensive m easu res to limit em issions from pow er statio n s, factories, and m o to r vehicles will be eith e r cost-effective o r necessary. In this ch ap te r we shall exam ine how acid rain is fo rm ed , and reserve until P art II consideration o f th e questio n ‘does acid rain really cause th e environm ental p roblem s widely attrib u te d to it (and if so, h o w )?’ T his lack o f com plete u n d erstan d in g o f how acid rain form s fuels the argum ent ov er how to reduce acidity and provides a co nvenient defence for those (like the B ritish and A m erican g o vernm ents) w ho are relu ctan t to com ply w ith the G en ev a C onven tio n . T h e tw o cam ps w ithin th e ra th e r p olarized d eb ate a d o p t radically differen t stances on this critical a re a o f u ncertainty (L a Bastille 1981:655). O ne g roup argues th a t we m ust u n d erstan d the processes involved before tak in g actio n , and th ere fo re th e m ost expedient solution at p resen t is to carry o u t detailed scientific studies to fill in the gaps in o u r u n d erstan d in g o f th e problem . T his tactic has been ad o p ted recurren tly in B ritain (see ch a p te r 10). T he o th e r g ro u p argues that it will tak e years to p ro d u ce unequivocal evidence, during which fish will continue to d ie, trees wilt, and lakes acidify. T hey argue th a t, because th ere is a d eq u ate (if not p erfect) evidence to link sources with p a tte rn s and effects, em issions (especially from p o w er stations) should b e reduced w ithout fu rth e r delay. T he d e b ate cen tres aro u n d acidity in rainfall, and th e effects o f this acidity after it lands on v eg etatio n , soils, lakes, and rivers. T h e co n cern is m ainly ov er acidification o f th e en v iro n m en t, fo r w hich acid rain acts as th e

Sources, patterns, and processes prim ary catalyst. B efore we co n sid er how acid rain is fo rm ed , it will be useful to clarify w hat acidity is and how it is m easured.

ACIDITY - DEFINITION AND MEASUREMENT AH elem en ts are com posed o f ato m s, which are m ade up o f stable elem entary particles called electrons. E lectro n s o rb it th e nucleus o f th e atom in num bers equal to th e atom ic n u m b er o f th e e lem en t. H ydrogen has the atom ic n u m b er 1, so it has o n e elec tro n ; oxygen, with th e atom ic n u m b er 8 , has 8 electro n s; and so on. T he stru ctu re o f an ato m is norm ally stable, but if groups o f ato m s o f differen t elem en ts com e in contact (norm ally by m ixing o f th e elem en ts) chem ical in teractio n s can occur in which one o r m ore elec tro n s are tran sferred from one ato m to th e o th e r. In this way ions (electrically ch arged ato m s o r gro u p s o f atom s) are form ed by the loss o r gain o f on e o r m ore electrons. T hose th at lose a re positively charged and called cations; those th a t gain a re negatively charged and called anions. H ydrogen ions a re form ed from hydrogen atom s th a t have lost th eir electrons and becom e positively ch arg ed (i.e. cations). A dictionary definition o f acid is ‘any substance th a t dissociates in w ater to yield a sour corrosive solution containing hydrogen io n s’ (C ollins 1982: 12). A cids in solution tu rn litm us p a p e r red . T h e opp o site o f an acid is a base, a solution o f which is an alkali (basic o r alkaline as adjectives). A lkaline solutions tu rn litm us p a p e r blue. A lthough we ten d to thin k o f acids as solutions (such as nitric acid), an acid is not necessarily a liquid in solution, although it can be dissolved to p roduce o ne. P articular acids are in reality cocktails o f ions, which can be dissolved. F o r exam ple, dissolved sulphuric acid an d nitric acid consist o f hydrogen ions plus sulp h ate and n itrate ions respectively.

The pH scale T he term ‘acidity’ is often used to m ean th e state o f being an acid, but it is m ore properly used to express th e am o u n t o f acid presen t in a solution (i.e. the num b er o f hydrogen ions in circulation). T his is norm ally stated as a pH value, w here p H is a sh o rt-h an d version o f ‘p o ten tial hy d ro g en ’. T he p H scale (F igure 2.1) runs from 0 to 14.0, w here 7.0 is n eu tral. P ure w ater has a pH o f 7.0, acid solutions have a pH less than 7.0 an d alkaline solutions a pH g re a te r th an 7.0. T he higher th e pH value, the g re a te r the alkalinity; th e low er th e valu e, th e stro n g er th e acidity. T he pH o f som e com m on household substances is show n in F igure 2.1, fo r com parative purposes. V inegar, w ith a pH o f aro u n d 3.0 is a fairly stro n g acid; soap solution, w ith a pH o f aro u n d 10.0, is a fairly stro n g alkali. A grow ing n u m b er o f scientists favour the use o f hydrogen (H +) ion concentration (a linear scale) to th e logarithm ic pH scale: ‘the use o f a linear rep resen tatio n o f co n cen tratio n s provides th e m ost a p p ro p riate m eans o f representing th e m agnitude o f any change in co n cen tratio n . . .

Figure 2.1

T h e p H scale, w ith th e p H o f som e com m on su b stan ces

pH value

a lk a l in i ty

14

STRONG ALKALI

■

—

cau stic soda

_

household ammonia

_

milk of magnesia

_

soap solution

13

increasing

12

11

10

• _

blood

NEUTRAL _

S ea W ater

Distilled W a te r - -

milk Pure Rain

_

wine and beer

_

orange juice

_

vinegar

—

lemon juice

_

stomach fluid

_

b a tte ry acid

increasing

acidity

> Acid Rain

STRONG ACID

Sources, patterns, and processes [and] . . . a w idespread ad o p tio n o f th e lin ear co n cen tratio n scale w hen rep o rtin g H + ion co n cen tratio n s, especially in acidic rainfall and freshw aters, w ould a p p e a r to be o v e rd u e ’ (L axen 1984:409). T he pH scale is a useful stan d ard fo r m easuring levels o f acidity, b u t ap p aren tly sm all differences in q u o ted p H values can be very d eceptive because th e scale is logarithm ic. T h e p H value is th e logarithm o f th e reciprocal o f th e con centration o f hydrogen ions. W hat this m eans in practice is th at relatively sm all differences in p H rep resen t p o tentially large differences in acidity. T h u s, for exam p le, a solution o f pH 6.0 is acidic, b u t a solution o f pH 5.0 is te n tim es as acidic an d a solution o f p H 4.0 is a h u n d re d tim es as acidic.

RAINFALL CHEMISTRY A lthough pu re (distilled) w ater has a pH o f 7.0, w ater m oving through the enviro n m en t is in contact with chem ical elem en ts. Som e are p ro d u ced by natural processes, bo th biological (e.g. th e decay o f dead p lants) and geological (e.g. volcanic eru p tio n s, and th e w eath erin g o f rocks). O th e r elem ents are prod u ced , norm ally as u n p lan n ed side-effects, by hum an activities (e.g. air pollu tio n ). T h ro u g h this contact th e w ater is co n tam in ­ ated. Som etim es the w ater b ecom es m ore acidic (e.g. stream s d raining acid peat bogs) and som etim es it becom es m ore alkaline (e.g. stream s flowing over chalk). B ecause o f this co n tam in atio n , norm al rainfall is never ‘p u re ’ (i.e. pH 7.0). T he ex ten t o f th e im purity varies from place to place, reflecting variations in th e source areas o f contam in an ts. Som e co n tam in an ts (e.g. am m onia, calcium , m agnesium , an d potassium - S um m ers 1983:82) m ake the rainw ater m ore alk alin e, w hereas o th ers (e.g. su lp h ur dioxide and nitrogen oxides) m ake it m ore acidic. M ost o f this variability in rain w ater chem istry stem s from th e distrib u tio n o f m an-m ade factors such as large cities, industrial com plexes, and p o w er stations. T his is a key ingredient in the acid rain d eb ate. It is critically im p o rtan t to establish th e b ackground pH o f n atu ral (uncontam in ated) rain, because this provides th e baseline against which increased acidity (caused by air p o llution) can be m easured and the exten t and significance o f th e increase d eterm in ed . A lthough th ere are spatial variations in the am oun ts and com position o f chem ical im purities derived from natural processes (e.g. volcanic eru p tio n s), th ese are believed to be m inor, certainly in com parison w ith m an-m ade factors.

How clean is clean? T he p H o f ‘clean’ o r pristine rain falling in areas rem o te from industry and o th er m an-m ade sources o f co ntam in an ts is generally tak en to be 5.6 (L ikens and B orm ann 1974; L ikens 1976; S um m ers 1983: 87), which is acidic in itself (see Figure 2.1). In fact this is tw enty-five tim es th e acidity of

25

26 Acid Rain distilled w ater. T his norm al rainfall acidity, entirely n atu ral in origin, includes w eak solutions o f carbonic acid (p ro d u ced from carb o n dioxide naturally presen t in th e atm o sp h e re , derived from plan t resp iratio n and o th e r sources) and sulphuric acid (p ro d u ced , for ex am p le, from volcanic em issions o f sulp h u r dioxide) (F ro h lin g er an d K ane 1975; L ikens et al. 1979). T his back g ro u n d acidity o f rainfall provides n a tu re ’s free supply o f fertilizers fo r p lants and trees, and is an essential m echanism in m aintaining the finely tu n ed chem ical balance in e n v iro n m en tal system s. T h e d eterm in atio n o f th e norm al p H o f rain is a vexed questio n but central to the acid rain d eb a te . E arly E u ro p ean rain w ater chem istry d a ta suggested th a t th e pH o f n on-polluted p recipitation is above 7.0 (O d en 1976); m ost scientists tak e n eu tral precip itatio n to have a p H o f eith e r 5.7 (B a rre tt and B rodin 1955) o r 5.5 (M rose 1966). T he C en tral E lectricity G en e ra tin g B o ard (C E G B ) has a stro n g vested in terest in the m a tte r, having been w idely accused o f co n trib u tin g to th e acid rain problem in B ritain (see ch a p te r 10) and Scandinavia (see ch a p te r 8). It prefers to q u o te a pH value o f 5.0 for pristine rain (1 9 8 4 :2 ). T his m ight a p p e a r to be a classical tactic o f m oving th e goal-posts while th e gam e is in progress, because th e baseline it seeks to be ju d g e d against is a hu n d red tim es as acid as distilled w ater, and four tim es as acid as the generally accepted norm . Som e scientists favour th e use o f p H 5.0 for natural rain, w hich ‘w ould seem to be m ore realistic’ (S um m ers 1983: 88) even if it does e rr on th e cautious side. T h e C E G B view is n o t en tirely w ith o u t fo u n d atio n , w hich com es partly from research carried o u t in Sw eden - paradoxically th e cou n try which has been m ost vocal o v er acid rain p ro b lem s in th e last d ecad e - at th e In tern atio n al M eteorological In stitu te in Stockholm (C harlson an d R o d h e 1982). T he Swedish scientists have d em o n stra te d th a t th e n atu ral su lp h u r cycle (w hich includes S 0 2 em issions from volcanic e ru p tio n s and dim ethylsulphide p roduced by biological activity on th e surface layers o f o ceans) can p ro d u ce large v ariations in space an d tim e in th e am o u n ts o f sulphur com pounds th a t d eterm in e th e acidity o f rain w ater. T hey fo und th a t average p H values in u n p o llu ted regions can be aro u n d 5.0 an d even fall as low as 4.5 (o v er tw elve tim es th e acidity o f pristine rain ), en tirely th rough n atural processes. W e shall note this significant lack o f ag reem en t b u t ad o p t th e norm al scientifically accep ted stan d ard pH fo r clean rain (5.6). In th e discussion th at follow s, ‘norm al acidity’ is tak en to have a pH o f 5.6, and observ ed levels are q u o te d in term s o f relative increases in acidity o v e r this background level.

ACIDIFICATION OF RAINFALL R ecent m easurem en ts indicate th at rains and snow s with a p H o f 4.3 o r low er fall regularly o v er m any o f th e highly industrial a reas o f th e n o rth ern h em isp h ere, especially N o rth A m erica an d n o rth ern an d w estern E u ro p e

Sources, patterns, and processes Table 2.1

Some reported rainfall acidity values

Location

Past pH

South-east England Eastern Scotland West Wales Netherlands West Germany Black Forest (West Germany) Southern Norway Northern Norway Southern Sweden Northern Sweden Northern Italy Switzerland Japan (around Tokyo) Canada (Quebec)

4.5-5.0

(1956)

4.5-5.0

(1956)

5.0-5.5 5.5-6.0 5.5-6.0 5.5-6.0

Present pH

(1956) (1959) (1956) (1959)

4.1-4.4 4.2-4.4 4.9

(1978) (1978-80) (1981-83)

3.97 4.25 4.7

(1979-80) (1972) (1977)

4.3 4.3 4.3-5.5 4.3-5.5 10 m icrom etres), so they quickly settle from the atm osphere - norm ally within a few hours. Finer particles (2-10 m icrom etres), on the o th er hand, have residence times in the atm osphere of up to a w eek. T here is consequently a rapid decline in the concentration o f large particles in com parison with the sm aller acidic sulphate and nitrate particles, so th at downwind the ratio of acidic to alkaline particles increases - i.e. the buffering influence declines (Sum m ers 1983). Because sensitivity to acidification varies from place to place (in harm ony with variations in buffer capacity), it is not possible to arrive at a precise value of precipitation pH below which dam age occurs. C onse­ quently the im pact o f acid deposition can vary considerably, even over

62 Acid Rain short distances. This variability is highlighted, for exam ple, in the English Lake D istrict, which receives am ong the highest acid fluxes in B ritain (B arratt and Irwin 1983). Lakes and vegetation on the Eskdale granites and the B orrow dale volcanics (which offer lim ited buffering potential) show clear sym ptom s of acidification, whilst o th er parts of the Lake D istrict, which receive a similar quality o f precipitation, show no signs of dam age (T aylor 1985). Some a re a s -s u c h as W ast W a te r - a r e p rotected by the natural buffering o f soils and bedrock, and o thers with limited natural buffering - such as E sthw aite - are buffered by n u trient enrichm ent from sewage and agriculture.

UNCERTAINTY AND COMPLEXITY T he acid rain debate is still shrouded in mystery and uncertainty, and this creates two pressing problem s - the ap parent ease with which ordinary m em bers o f the public can becom e alarm ed, and the extrem e difficulty of finding widely acceptable solutions to the problem . K enneth M ellanby has accused journalists o f providing ‘uninform ed nonsense’ about acid rain during the early 1980s, and he insists th at ‘th ere are still many uncertainties. W e simply do not understand the quantitative relationships betw een emissions and their environm ental effects’ (1984b: 87). The problem of linearity (see chapter 2) is far from properly resolved. In particular, the C E G B (1984: 6) in Britain argues that the rainfall acidities being m easured in many areas are too high to be accounted for only by gaseous oxides produced from the burning o f fossil fuels - unless those gases have been fu rther oxidized (e.g. by ozone) after emission into the atm osphere. This highlights the thorny problem o f linearity (see chapter 2), and reinforces the view th at it is difficult to attrib u te relative im portance of the many factors involved. Is S 0 2, for exam ple, responsible [for forest dam age] to an extent o f 30 percent, 40 percent o r 50 percent? The answ er must undoubtedly vary, not m erely as a function o f geographical area - e.g. from one country to another; geographical position (forest on a hillslope o r on a valley floor); the environm ent (nearby alum inium factory and release of fluorine) o r the tre e ’s state of health itself determ ined by the soil; the clim ate; techniques o f forest m anagem ent, etc; but also as a function of time (seasonal variations). (R ibault 1984) T he lack of unequivocal evidence linking acid rain with dam age to the environm ent reinforces official views in Britain and the U nited States that it w ould be precipitate at this stage to m ake binding decisions to reduce emissions of S 0 2 and N O x. The ap p aren t uncertainty gives a welcome breathing space to protagonists of m ore research, and an eagerly seized excuse for inactivity by som e governm ents (see chapters 8-10). T his ‘need for caution’ view is well articulated by the environm ental director for A m erica’s giant Peabody Coal C om pany, w ho argues:

Scientific complexities nobody has yet p roved a direct relatio n sh ip betw een th e level o f sulphur em issions in th e m idw est an d the am o u nt o f acid rain th a t falls in th e n o rth easte rn U n ited S tates an d C an ad a. A n d until we have this p roof, we should go slowly in o rd e r to d evelop th e m ost p ru d e n t control schem e. B efore being re q u ired to . . . red u ce em issions, we w ant assurance th at [it] will do som e good, (q u o ted in La Bastille 1981: 665) T he uncertainty reflects th e scientific com plexity o f th e p ro b lem . T h ere are few really d ram atic effects o f acidification, and m any o f th e inferred im pacts are extrem ely subtle if n o t largely invisible (even to th e train ed eye), at least in the early stages. B ut by th e tim e visible dam age occurs o r subtle effects have built up to a d etec tab le (and qu an tifiab le) level, m any o f the problem s are extrem ely serious and possibly irreversible. A cidified areas are n eith e r unsightly n o r ecologically d e ad , although m any norm al species d isap p ear and are replaced by a few acid -to leran t ones. T he m ost serious effects o f acid rain re p o rte d to d ate have been large-scale fish kills (fo r exam ple in Sw eden, w here o ver 9,000 previously productive lakes now have depleted fish stocks; A braham sen, Stuanes, and T veite 1983; Swedish M inistry o f A griculture 1984) and w idespread forest dam age (for exam ple in W est G erm an y , w here aro u n d o n e-th ird o f the coniferous forests are tro u b led by acidification; T am m and Cow ling 1977; E lsw orth 1984a; Postel 1984). M oreover, because o f v ariations in buffer capacity, different areas often show different sym ptom s o f acidification, even w hen exposed to th e sam e levels o f acid precipitation. C om plexity also arises because th e effects o f acid rain are n eith er sim ple n or direct. It affects the en v iro n m en t m ainly by alterin g n atu ral eq uilibria, upsetting the finely tu n ed natural chem ical balances and biological m echanism s on which life d ep en d s. It is now believed th a t acidification per se is not the critical issue, at least for wildlife. W hat is m ore significant is the chem ical chain reactions triggered off by acidification (such as th e m obilization o f toxic heavy m etals - see ch ap te rs 4 and 5), which produce the real problem s for plan ts and anim als.

Variability of response N ot all effects com m only a ttrib u te d to acid rain are seen in any o n e a re a , and one p articu lar puzzle is why d ifferen t effects are d etected in d ifferent areas. In W est G erm an y , fo r ex am ple, tree d eath s have caused co n sid er­ able concern (S traud 1980); in N orw ay it has been fish d eath s (Jensen and Snekvik 1972; A b rah am sen et al. 1976; B raek k e 1976; L eivestad and M uniz 1976). T he answ er lies partly in v ariations from place to place in th e form (w et o r d ry , also chem ical com position) and level o f acid d eposition (pH and total flux), as o u tlined in ch a p te r 2. S uperim posed on these are variations from place to place in n atu ral b u ffer capacity, which m ake som e areas m ore resistant to acidification th an o th ers. F o r exam p le, acidification of

63

64 Acid Rain freshw ater lakes is m uch less likely in th e alpine zone o f E u ro p e th an in n o rth ern E u ro p e because o f m ore fav o u rab le geological conditions. A lpine valleys aro u n d L ake M aggiore in n o rth e rn Italy receive acidic rainfall (pH betw een 4.3 and 4 .5 ), b u t th eir underlying geologies (insensitive calcareous rocks) buffer surface w aters, which have p H generally in th e range 5 .0 -9 .0 (m ost are betw een 6.5 an d 7.5) (M osello and T a rta ri 1983). D ifferent h ab itats also respond to given acidity levels in d ifferen t ways. T h u s, for exam p le, fresh w ater h ab ita ts a re m o re readily affected by acidification than soils and vegetatio n (including tree s). A lso im p o rta n t is th e en v iro n m en t o f th e a re a o ver which acid rains fall, p articularly if - as ap p ears to be th e case with W est G erm an y ’s forests - clim ate is at th e extrem e o f w hat a given vegetatio n (in this case co niferous tree s) will to lerate. If this is th e case, acidification can effectively be th e ‘straw th a t b ro k e th e cam el’s b a ck ’, an d even sm all am o u n ts o f acid rain m ight p roduce m uch w orse dam age th an w ould occur elsew here (even w ith m uch higher acid inputs). It is also tru e th at visible effects o f acidification have been d e te c te d in som e areas - such as u pland W ales (Scottish W ildlife T ru st 1985) - w here rainfall is not particularly acidic co m p ared w ith som e o f th e m ore high-risk areas (such as Sw eden and G erm an y ). T h ese a reas ten d to have high rainfall to tals, an d th e effects are cum ulative (reflecting n et fluxes of su lp h u r and n itrogen oxides - see ch a p te r 2). M o reo v er, th e affected areas have a range o f enviro n m en tal conditions th a t are collectively conducive to acidification. F o r ex am p le, fish d ea th s in W elsh rivers have been co n cen trated in areas with hard b ed ro ck , p o o r soils, an d large coniferous plantations. It is im p o rtan t also to distinguish b etw een effects th a t are ev id en t close to em ission sources (u rb an and industrial areas) and those th a t occur long distances dow nw ind. M ost o f th e local p roblem s for h u m an s, v eg eta tio n , and buildings a re caused by sh o rt-ran g e dry d eposition o f oxides and particles (see ch a p te r 2), an d they are o ften acute and th u s relatively easy to d etect. L onger-range w et and dry d eposition o f acids a p p ears to have chronic effects on terrestrial and aq u atic ecosystem s - tre e s, soils, lakes and rivers, p lan ts, and anim als - an d building m aterials, and these are m uch m ore difficult to d etec t. Strictly speaking th e acid rain d e b a te is ab o u t the effects o f long-range (tran s-fro n tier) acid d ep o sitio n , but the effects o f short-ran g e d eposition are also relev an t and they m ust be considered.

Biological acidification M oreover acid rain is only one co m p o n en t o f acidity, and it is necessary but not alw ays sim ple - to distinguish betw een acidification caused by acid deposition and acidification caused by o th e r processes, both n atu ral and m an-m ade.

Scientific complexities N atural biological processes have long been know n to cause acidification in soils and surface w aters. Biological acidification is th e result o f tw o processes (O d en 1976: 161-2) - nitrogen m etabolism and increasing excess alkalinity in plan ts - which p ro d u ce a net effect in which ions are lost from plants in a series o f pulses (m ost notably during spring and a u tu m n ). B iological acidification is en h an ced w hen th e pro d u ctio n o f organic m atter exceeds decom position , so th a t p eat bogs and forest peats a re norm ally very acidic. B ogm oss (S p hagnum species) secretes acid, h e a th e r (Calluna vulgaris) increases th e acidity o f soils and p erco latin g w ater, and pine forest naturally induces acidification o f soils. B ut th e reverse also holds tru e , and biological acidification d ecreases w hen th e re is a net loss o f organic m a tte r (e.g. w hen crops a re h arvested on fo rest an d farm land; B orm ann and L ikens 1979).

Afforestation and acidification C onsiderable atten tio n has been focused on th e links betw een acidification and forestry. T h ere are w ell-founded fears th at acid rain is dam aging forests in m any parts o f m ainland E u ro p e (see ch a p te r 5 ), but trees also affect soil acidity. T h e acidity o f soils is generally low er u n d er d eciduous trees th an u n d er conifers. C onifers increase soil acidity in tw o ways - biological acidification within and on the conifers, and chem ical en rich m en t as rainfall passes through the conifer canopy. T h e acidity o f precip itatio n can be increased by a factor of up to three as it drips from foliage, and by a factor o f betw een eight and ten when it flows dow n th e stem s o f spruce and pine (T aylor 1985). T h e w ashing o u t o f chem ical substances from conifer forest litter may increase acidity even fu rth er. In co n trast, b ro ad leav ed trees may serve to reduce the effects o f acid deposition by reducing th e co n cen tratio n of strong acids. R esearch has show n th a t com m ercial conifer p lan tatio n s can increase the possible dam aging effects o f acid d ep o sitio n , so th a t affo restatio n can increase the rate o f acidification o f rivers and lakes. B oth chem ical and physical effects are involved. T h e grow th o f trees rem oves basic ions from the soil, and this process reduces th e ability o f th e soil to neutralize acidity (i.e. it low ers th e soil’s b uffer capacity). Physical changes are in troduced via land drainage (norm ally by digging dense n etw orks o f drainage ditches), which p reced es p lanting. D rainage sp eed s th e rem oval o f w ater during w et p erio d s, and this red u ced co n tact with th e soil d ecreases the prospect o f chem ical neu tralization o f th e w ater th rough n atu ral buffering. T he net effect is to p ro m o te acid surges in stream s draining coniferous forests, which affect fish and th e p red ato ry birds (like dip p ers) th a t feed off them . T hus m any form s o f forestry m anagem ent serve to accen tu ate problem s of acidification, and a real p aradox em erges. M uch m arginal lan d , which is unsuitable for intensive farm ing use, is very sensitive to acidification

65

66 Acid Rain (because it has a low buffer capacity, o ften having acid soils overlying slow w eathering rocks) yet it is often reg ard ed as suitable for com m ercial conifer p lan tatio n s - which may fu rth e r increase th e pro b lem s o f acidification. M any p arts o f upland B ritain (including S cotland, W ales, and th e English L ake D istrict) and o th e r co u n tries are caught in this self-induced circle o f m arginality, susceptibility, an d accen tu atio n (H arrim an and M orrison 1981). T he links betw een afforestation and acidification are now becom ing clear, because the m ost w idespread fish d eath s in u pland B ritain have occurred in areas with h ard b ed ro ck , p o o r soils, and large conifer p lan tatio n s ( The Tim es, 14 Ja n u ary 1983). A s a result it is extrem ely difficult in m any areas to sep arate the possible effects o f an increased area planted w ith conifers from the possible effects o f acid d eposition (N ilsson, M iller and M iller 1982; G oldsm ith and W ood 1983; B inns 1982a).

The time dimension A n o th er critical uncertain ty is why m ost o f the p ro b lem s a ttrib u te d to acid rain in E u ro p e and elsew here are com ing to light only now , a fte r a long period during which oxide em issions have been increasing. S ulphur levels in th e atm osphere across E u ro p e as a w hole rose by aro u n d a half betw een the mid-1950s and the mid-1970s, th ough levels o v er S candinavia and central E u ro p e d o u b led o ver th e sam e p erio d ( The Tim es, 30 Ju n e 1982). M oreover, trend s in em ission levels have varied considerably fro m cou n try to country. U K p roduction o f S 0 2 and N O x reach ed a peak in th e 1960s, since w hen it has d ecreased m arkedly (p artly th rough th e rep lacem en t of sulphur-rich coal gas with low -sulphur N orth Sea gas) (see Figure 2.5) (C entral E lectricity G en e ra tin g B oard 1984; H M SO 1984). T h e puzzle is m ade even m ore com plex by th e fact th a t, although th e pH o f rainfall over these areas is presently low (i.e. rainfall is very acidic), th ere is no strong evidence to indicate th at the acidity has been increasing steadily in recent decades (see ch a p te r 2 ). T he evidence suggests th at acid rain has effects that a re indirect, cum ulative, and difficult to detect w ith precision. T h e re has been a tim e-lag betw een th e period o f peak S O i em issions and likely peak o f acid deposition (both in th e 1950s and 1960s in E u ro p e - W right 1983: 142), and the period o f m axim um dam age o bserv ed , o r at least re p o rte d (th e 1980s and probably longer). T he lag may reflect tw o tren d s superim posed on one an o th er. O ne is the gradual rundow n o f b uffer capacity o v er tim e, so th at an acid ‘w ar of a ttritio n ' slowly but progressively grinds th e enviro n m en tal system s into subm ission and eventual d efeat. T he o th e r is th e ‘d om ino effect': the progressive and cum ulative b reakdow n th rough tim e o f n atural environm ental system s (chem ical balances and biological m echanism s), so that as tim e progresses m ore and m ore elem en ts in th e system (o r dom inoes in a precariously balanced stack) are d istu rb e d , especially as ecologically significant th resh o ld s o r critical b reak -p o in ts are reach ed .

Scientific complexities Every cloud has a silver lining It is p erh ap s a p p ro p riate to end this c h ap te r on a positive no te. A cid rain has had a bad press in recen t years, and th e im plication is th at it always spells trouble for the en v iro n m en t and for hum ans. W hilst this is d oubtless tru e o verall, not all news o f acid rain is bad new s an d som e beneficial effects have been rep o rte d . T h e silver lining in som e acid rain clouds is the prospect o f gaining free nutrients. T h e su lphur and nitrogen oxides in acid precip itatio n can provide valuable n u trien ts th a t act as free fertilizers an d stim ulate p lan t grow th. It has been know n for ov er th irty years, for ex am p le, th a t atm o sp h eric S 0 2 could be usefully abso rb ed directly by th e shoots and leaves o f plants. Studies carried o ut at B rita in ’s G rasslan d R esearch In stitu te have found th at low con cen tratio n s o f atm o sp h eric S 0 2 can increase th e grow th o f th e p erennial ryegrass ( L oliu m p erenne), a com m on field grass on som e soils (C ow ling, Jo n es, and L ockyer 1973; The Tim es, 2 July 1973). M ore recently, studies o ff th e coast o f N o rth C arolina have found that nitrogen-enriched acid rains a p p e a r to en h an ce th e grow th o f p h y to p lan k ­ ton - th e m icroscopic m arine plan ts th at larger fish feed on (P aerl 1985; The Tim es, 2 July 1985). T his might significantly benefit com m ercial fisheries in shallow coastal w aters close to u rb an and industrial em ission sources o f sulphur and nitrogen oxides. Such conditions are typical o f the U nited S tates, th e U n ite d K ingdom , the B altic region, and the w estern Pacific w aters o f Ja p a n , K o rea, and C hin a, and th e poten tial econom ic benefits - as yet unassessed - should not be o v erlo o k ed w hen evaluating acid rain in global term s. O th e r exam ples o f th e p o ten tial b enefits o f n u trien t en rich m en t by acid rain are starting to em erg e from m any areas. H o w ev er, th e evidence available to d ate indicates th a t such benefits ten d to be localized. O verall, as yet, the bad new s (sum m arized in ch ap te rs 4, 5, and 6 ) far outw'eighs th e good.

CONCLUSION O ver th e last decade o r so, evidence o f env iro n m en tal dam age from acidification, which m any scientists a ttrib u te eith e r directly o r indirectly to acid rain, has started to a p p e a r in m any d eveloped co untries. T h e dam age attrib u ted to acid rain includes declining fish po p u latio n s, leaching o f acid m inerals from soils into surface w aters, forest d ecline, and increased plant disease (C ow ling 1982). T h e w idely docu m en ted evidence o f fish and tree d eath s, in particu lar, has been used extensively in political d e b a te and in th e m edia to highlight the urgency o f the acid rain problem and to stress th e need to em b ark on long-term program m es of rem edial action (particularly the reduction o f S 0 2 em issions from p o w er station chim neys) w ithout fu rth e r delay. In practice, how ever, it is extrem ely difficult to establish d efinite direct links

68 Acid Rain betw een S 0 2 em issions, rainfall acidity, an d observ ed effects on th e env iro n m en t. T his does n o t necessarily m ean th a t th ese th ree co m p o n en ts o f th e d eb ate are n o t linked causally. W hat it does m ean is th a t unequivocal evidence, stro n g enough to be en tirely convincing to politicians and th e electricity-generating a u th o rities (C E G B in B ritain) and com panies (in th e U n ited S tates), is ra th e r difficult to com e by. In th e U nited K ingdom , the P arliam en tary Select C o m m ittee th at investigated acid rain in 1984 (see ch a p te r 10) blam ed the C E G B fo r m ost o f the observed dam age to trees, lakes, and buildings, w hilst th e g o vernm ent to o k refuge in the call for m ore scientific evidence before m oney was spent on reducing em issions. But th e M em bers o f P arliam ent w ho sat on the C om m ittee w ere ‘convinced th at scientific u n d erstan d in g is sufficiently advanced to d em and action now ’, and they concluded that ‘while a direct and p ro p o rtio n al link betw een su lp h u r em issions and environm ental dam age is not scientifically p ro v en , the case against S 0 2 is telling enough and th e dam age severe enough th a t action m ust be taken before all th e evidence is in ' (W algate 1984:94). A sim ilar conclusion w as draw n in 1984 by a g ro u p o f en v iron m en tal consultants called in by th e E u ro p ean C om m unity to review th e acid rain problem in E uro p e: it has n ot been unequivocally established th a t [these] en v iro n m en tal im pacts are caused by acid p o llu tan t em issions . . . n evertheless circum stantial evidence w ould suggest th at acid em issions an d th eir su bsequent chem ical tran sfo rm atio n and precip itatio n are at least a partial contrib u to ry cause to th e observ ed effects an d m ay be giving rise to as yet unidentified im pacts, som e o f which could be irreversible. (E n v iro n m en tal R esources Ltd 1984:20) In the next th re e ch ap te rs we shall have the o p p o rtu n ity to exam ine th e m ain lines o f evidence - circum stantial o r otherw ise - th at have been used to link environm en tal dam age with acid dep o sitio n , and to ev alu ate the claim s m ade by m any enviro n m en tal groups th a t politicians in som e countries (like B ritain and th e U n ited S tates) have view ed th e acid rain problem with co n tem p tu o u s indifference.

4 EFFECTS ON SURFACE WATERS ‘Down by the riverside..

O ne may not doubt th at, som ehow , good Shall come o f w ater and of m ud; A nd, sure, the reverent eye must see A purpose in liquidity (R u p ert B rooke, Heaven) A s far as we are concerned in this book, the ‘purpose in liquidity’ is the rapid transfer o f dissolved acids through the environm ent. B oth dry and wet deposition contribute acid substances to natural biogeochemical cycles, which can show clear sym ptom s o f environm ental dam age from effective ‘overloading’. These natural cycles also move nutrients through ecosystem s, and so they widen the area over which ecological dam age from acidification can becom e evident. Thus acidification can - and indeed does - create problem s in habitats some way dow nstream from those areas that receive the acid deposition (which are them selves long distances downwind of emission sources), as well as in the im m ediate vicinity of the deposition. T he aim in this chapter is to review some o f the evidence that might link ecological changes in aquatic ecosystems with acidification (w hether this be induced by acid rain o r natural processes). Ecological dam age to lakes and rivers has been reported in many areas since the mid 1970s (H agen and Langeland 1973; A im er et al. 1974; Beamish et al. 1975; A braham sen el al. 1976; B raekke 1976; D epartm ent of E nvironm ent 1976; D rablos and Tollan 1980; From m 1980; M uniz and Leivestad 1980a, b; O verrein, Seip and Tollan 1981; M osello and T artari 1983; V angenechten 1983; W right 1983; E nvironm ental R esources Ltd 1984; Royal Society 1984; Swedish Ministry o f A griculture 1984), and the observed changes follow a series of quite clearly defined trends and patterns. T he dam age is random neither geographically nor ecologically, and this lends substance to tne claims that S 0 2 and N O x emissions ap p ear to be the ultim ate source (how ever modified in transit through the atm osphere - see chapters 2 and 3) o f the acid precipitation that appears to cause fish deaths and biological changes in freshw ater habitats.

70 Acid Rain ACIDIFICATION OF SURFACE WATERS In m any areas (p articularly in Scandinavia and th e N o rth e a st U n ited S tates) it has been suggested th a t increased acidity (declining p H ) of p recipitation has been p aralleled by a decrease in th e p H o f stream and lake w aters. Surface w aters offer m uch less p rospect of buffering acid inputs than do soils and plants. C onseq u en tly stream s an d lakes norm ally show clear signs o f acidification som e tim e b efore it becom es a p p aren t in soils, p lants, and forests. T he m ost d ram atic sym ptom s are th e decline an d possible loss o f p o pulations o f fish and o th e r species from acidified lakes, rivers, and reservoirs (L ikens et al. 1979), and it com es as no surprise th a t such evidence has been w idely used by conservationists in th eir cam paign to reduce S 0 2 and N O x em issions from pow er statio n s, houses, vehicles, and industry. In so u th ern N orw ay, fo r exam p le, fishery in sp ecto rs at th e tu rn o f the century n o ted fish kills o f salm on possibly related to acid w aters, and brow n tro u t began to d isap p ear from m any m o u n tain lakes durin g th e 1920s and 1930s. By th e 1950s, b arren lakes w ere being re p o rte d from m any p arts o f so u th ern N orw ay, and com m ercial fishery catches w ere declining in p arts o f S w eden, especially along th e w est coast (W right 1983: 137). B ut fish d eath s are m erely the tip o f th e acid iceberg, because acidification affects surface w aters in a variety o f ways that are not always visible o r easily d etec ted . It is difficult to specify at w hat precise p oint a lake o r river becom es ‘acidified’, because surface w aters in som e (w ell-buffered) a reas can to lerate m uch higher levels o f acidity than o th ers. T he definition should be based on biological criteria (e.g. dam age to fish), b u t this is closely co rrelated with a sim ple chem ical definition. It is widely ag reed th a t, once the pH o f surface w aters falls below 6 .0 , chem ical an d biological conditions change so significantly th at for all in ten ts and p urposes th e w ater can be reg ard ed as ‘acidified’. A s pH falls even low er, th e acidification intensifies and the problem s magnify and diversify.

EVIDENCE OF RECENT CHANGES A cidified lakes (p H less th an 6.0) have now been re p o rted from m any areas. T h e w orst-hit areas up to now have been so u th ern N orw ay (F igure 4.1a) and Sw eden (Figure 4 .1 b ), th e A diro n d ack M ountains in N ew Y ork state (U S A ), sou th -east O n tario (F igure 4 .1e), and o th e r p a rts o f eastern C anada (W right et al. 1980a; La B astille 1981). B ut acid lakes have also been found in B elgium , D en m ark , W est G erm an y , and th e N eth erlan d s (W helpdale 1983: 78), and scientists expect sym ptom s o f acidification to a p p e a r in m ore and m ore co u n tries if recen t increases in rainfall acidity continue unchecked. G reat B ritain h as n o t escaped u n to u ch ed . Since 1982 som e lakes in G allow ay in south-w est S cotland, an d som e rivers in th e English L ake

Figure 4.1

D istrib u tio n o f acidified lakes in so u th e rn N o rw ay , w estern S w ed en , O n ta rio , a n d a lp in e Italy

c

30

d Ita ly

La C lo c h e M o u n t a in s , O n t a r io 66 la k e s , 1 9 7 2 -3 pH=

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a lp in e l a k e s , 1981

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pH

Sources: a-c after Wright and Gjessing (1976): (d) after Mosello and Tartari (1983) Note: The data are plotted as frequency distributions of the pH in lakes, expressed as a percentage of lakes falling in each successive pH class. pH below 6.0 is taken to be ‘acidified’.

72 Acid Rain D istrict and in cen tral W ales have been ad d ed to th e casualty list (W right et al. 1980b; Sutcliffe e ta l. 1982; B a ttarb e e 1984; Scottish W ildlife T ru st 1985; Sutcliffe and C arrick 1986). M ost o f these a reas have g ran ite o r o th e r highly siliceous b ed ro ck , soft an d poorly bu ffered surface w aters, and highly acid precip itatio n (average pH below 4.5). L akes in w ell-buffered areas, such as th e alpine lakes o f n o rth e rn Italy (Figure 4. Id ) are generally m uch less acidic than those in poorly bu ffered areas (contrast Figure 4 .Id w ith 4 .1 a-c). T h e acid lakes in Belgium an d the N eth erlan d s are related m ore to th e p resence o f thick dep o sits o f siliceous sand s th an to acid precip itatio n (W right 1983; 138). It is difficult to establish how m uch th e acidity o f surface w aters has changed through tim e in m ost areas, because it is only recently th a t reliable an d regular m easu rem en ts have been tak en . W h at evidence we do have show s th at m any o f to d ay 's acidified lakes w ere not so even in the recent past. T h e pH o f 187 lakes in so u th ern N orw ay was m easu red at various d ates betw een 1923-49 and the 1970s, and the results (F igure 4.2a) show a fall in p H (in the o rd e r o f 1 p H u nit, i.e. a ten-fold increase in acidity) o ver th at perio d (W right 1977). Sim ilar m easu rem en ts indicate a m ark ed fall in pH in 51 lakes in so u th ern Sw eden betw een 1935 and 1971 (F igure 4 .2 b ), and in lakes in New Y ork sta te ’s A d iro n d ack M oun tain s betw een th e 1930s and 1975 (F igure 4.2c). O b serv atio n s o f the changing w ater chem istry o f G eorge L ake in C an ad a (B eam ish et al. 1975) show th a t pH fell on average aro u n d 0.13 units p er y ear betw een 1961 and 1975. T his re p resen ts a total fall o f aro u n d 1.7, o r a fifty-fold increase in acidity o v er th e fo u rteen -y ear period. A less dram atic b u t none th e less im p o rtan t d ro p in p H has been noted for th e R iver K laralven in S w eden, from 6.9 in 1965 to 6.5 in 1974 (O d en 1976; 154-5). H ow ever, whilst such w ater chem istry evidence provides a clear picture of changing levels o f pH in surface w aters, it does m ask considerable variability in acid levels o ver short tim e-p erio d s which m ight be o f g re ate r biological significance. F o r exam p le, sh o rt bursts o f acidity - p erh ap s during spring snow m elt o r after p ro lo n g ed d ro u g h t (see ch ap te r 2 ) - can cause w holesale biological distu rb an ce b u t escape d etec tio n in th e g eneral figures on long-term changes in surface w ater pH . Biological records can also be used to confirm how recen t m ost surface w ater acidification has b een . O v er 20 p er cent o f th e lakes in so u th ern N orw ay th a t are now b arren lost th eir fish during th e 1970s, and in over h alf o f the 700 lakes with sparse fish p o p u latio n s the decline has been very recent (W right 1983; 140). B etw een 1929 and 1937, only a few lakes in th e A d iro n d ack M ountains in th e N o rth east U n ited S tates had a p H below 5.0, but by th e m id 1970s alm ost half o f th em had (see Figure 4 .2c), and by then 90 per cent o f th e lakes had lost th eir fish stocks (Schofield 1976). T he evidence indicates a progressive decline in w ater quality (i.e. a fall in p H ) in all areas th a t receive high inputs o f acid substances (w h eth er from n atural o r m an-m ade sources). If recen t tren d s c o n tin u e u n ch eck ed , th e re fo re , we should expect to find progressively m ore and m ore stream s

Increasing acidity of lakes through time in southern Norway, southern Sweden, and the Adirondack Mountains (Northeast United States)

Figure 4.2

( c ) Ad ir o n d a c k M o u n t a i n s , New York ( 2 1 6 l ak e s ) 4.5) soils are often subject to intense agricultural m anagem ent, including fertilizer applica­ tions, drainage, and liming. D eterioration of soil quality in many agricultural areas has been prevented by the application of lime (a calcium product), which will norm ally also serve to neutralize the effects of pollutant acidity (Last and Nicholson 1982:250).

Complexities and complications T he effects of acid deposition (wet and/or dry) on soils are often difficult to detect, for various reasons. O ne is that acids can also be created by som e natural processes within the soil (Last 1982). T hese include biological processes (e.g. the breakdow n of dead organic m atter) and the w eathering of m ineral soil particles. Some soil scientists now argue th at the addition of acids to many soils through acid deposition is alm ost insignificant com pared with the levels o f production of acids by natural soil processes and agricultural soil m anagem ent (K rug and Frink 1983; T abatari 1985). A s a result, they argue, the possible interactions betw een acid rain, acid soil, land use, and vegetation on a w atershed need to be carefully assessed when evaluating the benefits that can be expected from proposed reductions in S 0 2 and NO* emissions (see P art IV). A second com plication is that acid deposition (at low levels of acidity, and in nutrient-deficient soils) can produce apparently beneficial effects on soils and vegetation, acting as a fertilizer via the provision o f free nutrients (especially o f sulphur and nitrogen) (A braham sen, Stuanes, and Tveite 1983). In many areas, acidification (w hether from natural processes o r via acid

Effects on soils and vegetation deposition) dam ages soils by altering their m icrobiology, chem istry, and fauna. T here are two main biological effects of increased soil acidity. O ne is a reduction in the rate o f bacterial decom position, through a slowdown in the organism s that break down litter on th e soil surface. The second is a reduction if not lim itation in the rate at which plant roots can absorb soluble m aterial (such as soil m oisture and dissolved nutrients). Both effects can produce significant changes in soil structure and productivity, and in turn in vegetation. A complex series of chemical reactions takes place when soil is acidified, the most im portant of which are believed to be the replacem ent of basic cations (K + , C a++ , M g+ + , N a+) by hydrogen and alum inium ions. This cation exchange process produces two chemical effects that fu rth er alter the soil and in turn produce problem s for the plants growing in that soil. The prim ary effect is to increase the leaching of cations from the soil and thus reduce the availability of nutrients within the soil. The secondary effect is to dissolve and mobilize (thus liberate) toxic heavy m etals that are present but norm ally chemically ‘bound up' (thus not freely available) in the soil. A cidification may also increase the w eathering of silicate minerals in som e soils, leading to loss o f m ineral structure and possible soil im poverishm ent (and reduced fertility).

Nutrient deficiency O ne im m ediate im pact o f an input of acids is to increase the exchange betw een hydrogen ions and the nutrient cations potassium (K ), magnesium (M g), and calcium (C a) in the soil. As a result these cations are liberated within the soil, and they can be rapidly leached out in solution in the soil w ater along with the sulphate from the acid input (A braham sen, Stuanes, and Tveite 1983; T olba 1983; Van B reem an, Driscoll, and M ulder 1984). A n increase in soil acidity (decrease in soil pH ) norm ally brings increased leaching of potassium , m agnesium , and calcium , and the greater the increase in acidity the g reater the loss of these nutrients from the soil. Poorly buffered sites often show a progressive loss of base cations (especially exchangeable Ca and Mg) through tim e. For exam ple, there are records of decreasing am ounts of potassium , m agnesium , and calcium in the soils beneath som e Swedish forests over a ten-year period during which acid deposition prom oted a decline in soil pH (A braham sen, Stuanes, and Tveite 1983). Plants require these m acro-nutrients for grow th and survival, and they take them in dissolved in soil m oisture through th eir roots (by root osmosis), in variable but generally relatively large quantities. Consequently, acid-induced leaching leads to nutrient deficiency in the affected soils, and this loss of soil fertility leads to a slowdown in the rate o f grow th o f plants and trees on acidified soils. N utrient availability within trees (and o th er plants) is also influenced by chemical exchange processes that take place on the leaf surface (A braham -

94 Acid Rain sen et al. 1976). A m m onia and nitrogen, which land on the leaf via acid deposition (wet and dry), pass through the sem i-perm eable m em brane on the leaf surface and are incorporated within the leaf cells. T h ere a chemical interaction (cation exchange) takes place, and those n utrients th at are available in abundance (e.g. potassium , calcium , m agnesium , and sulphur) are leached from and get washed off the leaf surface. It is not clear w hether this foliar leaching process significantly affects the nutrient status o f the trees o r not. It is believed that the adverse effects o f reduced nutrient uptake via soil m oisture far outweigh the problem s o f foliar leaching. N atural undisturbed ecosystems have complex nutrient cycling m echan­ isms that ensure th a t essential nutrients are available in sufficient quantities and in suitable form s. Thus the nutrients stored in living plants are released back to the soil when the plant dies and its body is decom posed by bacteria and m icro-organism s within the soil. If this cycle o f grow th and decay is allowed to proceed u n in terru p ted , natural biological mechanism s ensure long-term stability in nutrient availability. B ut w hen part or all o f the living products in an ecosystem are cropped (e.g. tim ber harvesting in forestry, o r the harvesting o f agricultural crops), the nutrient cycle is short-circuited and there is a net loss of nutrients (in the harvested produce). Fears have been expressed over the real prospect of nutrient depletion w here traditional forest felling practices are replaced (as in parts of eastern C anada) by w hole-tree harvesting techniques. In traditional practices only the main tree trunks are rem oved, and all o th er dead wood is burned o r left to decay on site (thus replenishing at least part o f the nutrient loss). In w hole-tree harvesting techniques, in contrast, all m aterial is rem oved from site and th ere is a wholesale loss o f nutrients. O ver the long term such accelerated nutrient depletion may lead to declining forest yield and further increase the susceptibility o f tree growth to the im pact o f acid deposition. A cidification can also affect nutrient cycling (thus availability of nutrients) in soils by changing the rate at which dead organic m atter is broken down and consequently the rate at which nutrients are liberated back to the soil. E xperim ental studies show that strong acidification retards the decom position o f litter o f spruce, pine, birch, and o th er cellulose-rich m aterials (T am m , W iklander, and Popovic 1977; Francis 1982; K illham, F irestone, and M cGolI 1983). This reduction in rates o f decom position can in turn produce several effects, the m ost im portant of which are: • reduced respiration by organism s within th e soil (including b acteria), • increased levels of am m onia in the soil caused by a reduction in the m obilization o f nutrients (previously released in decom position), and • decreasing soil n itrate levels (because o f am m onification). Such changes in soil chem istry may exceed the tolerance limits (see chapter 4) o f m any soil anim als, and so population changes may be expected in acidified soils. E xperim ental studies (A braham sen, Stuanes, and Tveite 1983) with soils at pH below 3.0 show a decreasing total abundance of

Effects on soils and vegetation enchytraeids, likely increases in th e ab u n d an ce o f springtails, an d no observed changes in the ab u n d an ce o f m ites.

Mobilization of heavy metals Increased soil acidity is o ften closely associated w ith increased co n c en tra­ tions o f som e toxic heavy m etals. T h e m ost com m on are alum inium (A l), cadm ium (C d ), zinc (Z n ), lead (P b ), m ercury (H g ), m anganese (M n ), and iron (F e) (T olba 1983:117). T h ese m etals, d eriv ed from n atu ral w eath er­ ing processes and sto red w ithin th e soils, are m obilized (i.e . they becom e m ore soluble in soil w ater) in th e p resence o f acids. T his m obilization encourages th e rapid sp read o f th e m etals th ro u g h soils, in n atu ral flows of soil w ater. From soils th ey can be w ashed into lakes and rivers (see c h ap te r 4) and tak en in by plants and tre es (via ro o t osm osis). T h e heavy m etals can also co n tam in ate g ro u n d w ater and be w ashed into reservoirs, and in turn passed on to h um an s (see c h a p te r 6). H ow ever, as with n u trien ts, th e position can p ro d u ce e ith e r benefits o r problem s, dep en d in g on th e co n cen tratio n s involved and critical th resholds o f biological activity. S om e m etals (such as M n an d F e) p rovide essential m icro-nutrients th a t stim ulate p lan t grow th at low co n cen tratio n s. H ow ­ ev er, at higher concen tratio n s the sam e m etals can be extrem ely toxic and greatly reduce p lan t grow th. T h ere is now little d o u b t th a t an increase in soil acidity brings higher am ounts o f alum inium an d o th e r heavy m etals in soils. B ut th e critical question rem ains: ‘W hat dam age does it cau se?’ Scientists are divided o ver th e issue, and m uch basic research rem ains to be d o n e before categorical conclusions can be draw n. It is know n, for exam p le, th at m any tre e species have ad ap te d to an acidic soil en v iro n m en t with high alum inium co n centrations (A b rah a m se n , S tu an es, and T veite 1983), and they can apparently to lerate q uite high co n cen tratio ns o f som e heavy m etals in th e soil. H ow ever, o n e view , based on findings o f large am ou n ts o f alum inium in soils in dam aged forests o f c en tral E u ro p e (U lrich , M ayer, an d K hanna 1980), is th at increased co n cen tratio n s o f alum inium dam age plants directly. T h e U lrich theo ry is th a t alum inium dam ages the fine ro o t hairs o f p lants and this reduces th e u p tak e o f p h o sp h o ru s and o th e r essential n u trien ts. In tu rn th e p lan t w ithers and may eventually die - if not from n u trien t starvation th en possibly from reduced resistance to severe w eath er (cold o r dro u g h t) o r disease. It is difficult to speculate ab o u t w h eth er o r n o t such dam age might em erge in Scandinavian forests, because as yet relatively little is know n in detail ab o u t alum inium co n cen tratio n s in forest soils th ere (A b rah am sen , S tuanes, and T veite 1983), o r ab o u t th e heavy m etal to leran ce o f the N orw ay spruce (one o f S candinavia’s most im p o rtan t tree species). B ut th e dram atic loss o f fish in m any lakes and rivers in so u th ern N orw ay and Sw eden (ch ap ter 4) d o es in dicate a clear likelihood o f heavy m etal m obilization and inw ash into surface w aters.

96 Acid Rain Sim ilarly, recently observ ed dam age to lakes and rivers in p arts o f upland B ritain (p articularly in W ales and Scotland) suggests th a t unacceptably high co ncen tratio n s o f heavy m etals (especially alum inium ) m ight well be involved.

EFFECTS ON VEGETATION It has long been know n th a t high co n cen tratio n s o f su lp h u r in the a tm o sp h ere can dam age vegetatio n . F o r exam ple, in 1913 ex p erim en ts w ere carried o ut o n th e grow th o f lettu ces in differen t p arts o f L eeds in north-w est E n g lan d , w hich show ed a close co nnection betw een v ariations in th e am o u n t o f su lp h ate in th e air o v er d ifferen t p arts o f th e city and variations in th e size and quality o f lettuce grow n (G o u d ie 1984). M ore recently, vegetation ‘d e se rts’ and clear spatial zo n atio n s o f vegetation aro u n d point sources o f S 0 2 pollu tio n (such as alum inium sm elters in N orw ay - G ilb ert 1975) have b een d o cu m en ted in m any areas. T ree canopies are o ften red u ced if not totally absent w ithin a b o u t 6 km o f sm elter p lants, an d few pine trees are found w ithin 25 km o f such p oint sources (W oodw ell 1970). M ost o f the early in terest cen tred on such local biological effects. Since th e m id-1970s, how ever, in terest has b ro ad en ed to include th e possible effects on vegetation o f long-range (p erh ap s tran s-fro n tier) d eposition (w et and dry) o f acid m aterials.

Lichens as air pollution indicators T h e best biological indicators o f air quality are lichens - flat p lan ts th at occur on a wide range o f types o f surface (including tre e tru n k s, rocks, w alls, and the g ro u n d ). D evoid o f ro o ts, lichens rely for n u trien ts on dissolved solids in rain w ater th at w ashes o v er th em . T h e w ater and n u trien ts are ab so rb ed th rough th e w hole body surface o f th e lichen (M abey 1974: 102-5); th e lack o f b uffer capacity (in th e absence o f soils) m eans th at lichens a re directly exposed to p o tentially high levels o f acidity in rainfall. L ichens (especially th e corticolous species) are very sensitive to (th u s in to leran t of) S 0 2 poisoning, and they provide a sensitive ‘biological litm us’ indicator (F erry , B addeley, an d H aw ksw orth 1973): th e w orse th e SO? pollution, th e few er th e types o f lichen th a t can survive. It is not know n exactly how acidity affects lichen co m m unities, but it is believed th a t tw o m echanism s a re involved (H ale 1974; A rvidsson 1985; B erlekom 1985d). M inerals in th e su b strate m aterial exist in differen t chem ical states u n d er different chem ical regim es, so th a t n u trien t availability to th e lichens will probably vary with varying rainfall acidity. M o reo v er, it is likely th a t th e rate o f n u trien t assim ilation in lichens varies w ith changing p H . L ichens have rarely been fo und in th e cen tres o f m ajo r cities, such as B onn, H elsinki, S tockholm , Paris, o r L ondon (G o u d ie 1984), which are

Effects on soils and vegetation - o r have been in the recen t past - often exposed to high co n cen tratio n s o f S 0 2 from traffic, industry, p o w er-g en eratin g utilities, and dom estic chim neys. Im provem en ts in air quality th at have follow ed th e in troduction of air pollution legislation have b een accom panied in m any cities (e.g. L ondon since 1960 - see c h ap te r 1) by reinvasion o f lichen species. Lichen distributions also provide a m eans o f exam ining air pollution over w ide areas. Field studies in dicate th a t by 1970 epiphytic lichens (which grow on o th e r p lan ts, m ainly trees) had d isap p eared from a b o u t a third o f E ngland and W ales (in a b elt running from L ondon to B irm ingham , through th e M idlands, and b ro ad en in g to include m ost of L ancashire and W est Y orkshire and p arts o f T yneside - th e trad itio n al heavy industrial axis) (H aw ksw orth and R ose 1970). R ecen t studies of lichen populations in th e B orro w d ale w oodlands in th e cen tral p art o f the E nglish L ake D istrict (T ay lo r 1985) indicate an increasing ab u n d an ce of acid-tolerant lichen species accom panied by a red u ctio n in th e p resence of acid-sensitive lichens, a ttrib u te d to acid d eposition.

Trees and higher plants H igher plants (h erb s and grasses, shrubs and trees) a re also adversely affected by S 0 2 and acid dep o sitio n . T he dam age arises in tw o ways through foliage (w hich is directly exposed to acid rain and fogs, an d to dry fallout o f oxides and particu lates) and th ro u g h ro o ts (w hich are affected by soil n u trien t deficiency and alum inium poisoning). Visible dam age to v eg etatio n can assum e various form s d ep en d in g on the ch aracter and level o f th e acidification, and th e buffer capacity o f th e area. C om m on sym ptom s include d irect physical dam age to p lan t tissues (especially ro o ts an d foliage) - red u ced canopy cover, crow n dieb ack , and w hole tree d eath (T am m and C ow ling 1977; T om linson 1983; B uckleyG o ld er 1985) - and red u ced grow th rate o f p lan ts (hence declining crop yields in farm ing and fo restry ). A typical sequence o f sym ptom s o f progressive dieback o f B ritish beech trees is show n in Figure 5.1. H ow ever, sym ptom s vary betw een species, and even w ithin a given species it is often very difficult to recognize th e sym ptom s o f dam age. Injury to vegetation is not alw ays m anifest by visible dam age to leaves; it can occur as reduced plan t g row th, reduced capacity for flow ering, and Figure 5.1

Typical stages in the dieback of British beech trees

Stage i (nor mat)

S ource:

a fte r A n o n (1985)

Stage 2 (pa rtia l dieback)

Staga 3 (advanced dieback)

Stage 4 (com ple te d ie b a ck)

97

98 Acid Rain reduced yield, and each o f these sym ptom s might take som e years to spot with certainty. Early signs of dam age can be overlooked even by the keen and w ell-trained eye, so th at adverse effects only becom e ap p aren t when they reach critical and perhaps irreversible proportions.

Germination and growth rates N atural regeneration o f plants is one o f n a tu re ’s inbuilt self-repair m echanism s, and it is o f critical im portance if dam aged plants are to be replaced. E xperim ental evidence is available for Norway spruce, Scots p ine, and silver birch seeds (A braham sen, Stuanes, and T veite 1983) that indicates that germ ination rates are m oderately inhibited w hen soil pH is betw een 3.8 and 5.4. The germ ination o f birch seeds is inhibited at lower soil pH . T he initial establishm ent of seedlings appears to be m ore sensitive than germ ination to soil p H , and it is known that the establishm ent of Norway spruce, Scots pine and silver birch decreases rapidly when soil pH drops below 4.2. F or this reason, reforestation of areas dam aged by acid deposition is often not possible, because new trees struggle for a few years then eventually they lose their vitality in the poisoned air and soil (H alford 1986: 16). G row th rates are best m easured by the annual rate o f increm ental increase of tree rings. T here is evidence from som e forests o f declining widths of annual grow th rings through tim e, even in healthy trees (see Figure 5.2). But studies of tree-ring grow th rates in sam ple areas of Norway and Sweden with different levels of acid input found no unam biguous trends, and grow th rates w ere not found to be reduced systematically in areas with high rates o f acid deposition (A braham sen et al. 1976). H ow ever, n either is there ‘sufficient evidence to state th at acid precipitation has no effects, as fu rth er acid deposition on forest ecosystem s Figure 5.2

Declining annual growth-ring widths in damaged silver fir trees in the Alpirsbach forest district of West G erm any, 1940-83

Source:

a fte r S c h ro te r (1985)

Effects on soils and vegetation could cause unknow n changes in th e chem ical and biological p ro p ertie s o f th e soil th a t could affect its overall pro d u ctiv ity ’ (Lesinski 1983:158). A com m on p a tte rn in tre e grow th studies is to w itness increased grow th o f tre e height and tru n k d ia m e te r in th e early years o f ex p erim en tal plots (w ith acidity levels sim ilar to those presently fo und in S candinavia) com p ared with sim ilar p lo ts with no acids a d d e d , follow ed by e ith e r no difference betw een the tw o sets o f plots o r a red u ced rate o f d iam eter grow th in the acidified o n es (A b rah a m se n , S tu an es, and T veite 1983). T he initial grow th increase p robably reflects th e stim ulatory effect o f n u trien t provision (see Figure 5.3).

Physical damage to trees It is th e visible dam age to tre e s th a t has given rise to m ost co n cern , especially in W est G erm an y , p a rts o f th e E aste rn U n ited S tates, and C an ad a, and m ore recently in Scotland. V isible dam age ten d s to be co n cen trated in o ld er and m ore established tree s, an d it a p p ears to be species specific. O n e o f th e m ost sensitive tre e species is Scots pine. T his is a very significant co m p o n en t o f the forest econom y in m any countries (such as Poland - Lesinski 1983: 158). so th a t acid-induced forest dam age may have serious conseq uen ces for national econom ies and som e aspects o f international tra d e in raw m aterials. T h e exact form and severity o f th e dam age varies according to the c h aracter and m agnitude o f th e air po llu tio n , so th a t visible evidence of Figure 5.3 Initial growth increase followed by slower growth rates in trees under acid deposition

Source: after Abrahamsen, Stuanes, and Tveite (1983) Note: Based on field experiments in a Scots pine sapling stand, in which trees were watered with 'acidified' rain

100 Acid Rain physical dam age varies considerably from place to place. Sym ptom s of dam age ap p ear with varying intensity, and in various com binations. The m ost com m on sym ptom s o f disease show n by dam aged conifers (see Figure 5.4) are yellowing needles, loss o f needles, distorted branches, thinning tops, bark injuries, trunk changes, and dam age to fine root fibres (A gren 1984a: 6). C om m on tell-tale signs in Scots pine (Lesinski 1983) include: • • • • •

needles becom e shorter durability of the needles decreases (from th ree years to one year) top buds dry up annual increm ents o f shoot length becom e sm aller the shape of the tree crown changes.

In deciduous trees (see Figure 5.1) the main visible sym ptom s are discoloured and deform ed leaves, early shedding of leaves, d eath o f part of the tree top, bark injuries, and a lack of natural regeneration (A gren 1984a: 6). U nder extrem e conditions, the tops o f injured trees (deciduous and coniferous) die earlier than the branches further dow n, giving a curiously dismal appearance to som e forests. This form o f crown dieback has been particularly pronounced in W est G erm an forests.

WALDSTERBEN - DAMAGE TO WEST GERMAN FORESTS W orld attention has been focused on the forests of W est G erm any, w here tree dam age has been most acute and is now well docum ented, and which appear to have suffered from dram atic increases in the level and type of dam age in recent years. T ree dam age first cam e to light when diseased fir trees were found in the Black Forest in the early 1960s. W hat was initially viewed as probably a local problem had clearly intensified by the late 1970s, w hen som e experts concluded that one-third of the fir trees had died already and half o f the rem aining ones may be term inally ill (H alford 1986: 15), and fears were expressed for the future o f the Black Forest (M ay 1982: 11). C oniferous trees (fir and spruce) in the Black Forest have been worst affected, and ‘instead of lush, dark green foliage that gave the Schwarzwald [Black Forest] its nam e, many trees now have only sickly yellowybrow n needles’ (H alford 1986: 15). But o th er tree species in the forest are also showing signs of dam age: half the beech and 43 per cent of the oaks are affected, and many elm trees are dying at 60 years old rath er than the m ore norm al 130 o r so years (H alford 1986: 16). T he dam age appeared to be caused by some form o f disease described as a ‘baffling form o f tree “cancer” ’ (Tifft 1985: 45), and it produced striking visible sym ptom s in affected trees. D am age in the spruce, for exam ple, was vividly described by Tim e magazine: the dark green branches at first hang limply, like Spanish moss. B etw een three w eeks and five years later, the branches are tinged with

Figure 5.4 Typical sym ptom s of dam age in coniferous trees subject to acid rain, with assum ed processes ACID DEPOSITION

m

' A Gas, aerosol * and particles Thinning of Crown ('C row n d ie -b a c k ') b

Shedding of leaves and nee

i

Decreased resistance to drought, disease frost etc.

Direct damage to TREE WEAKENED BY: needles, leaves and bark Lack of Nutrients Excess of poisons Loss of nutrients from leaves (Leaching) e.g. Ca,Mg

*

b

j, Failure of seedlings Acidification o ftop, soil ----------------------' Decomposition slowed down Nutrients Washed Away (e.g. Mg,Ca)

Changes in organic life

' Damage to fine root h a irs '\

SOIL ACIDIFICATION

I f }t t t I t t t \ \ Reduced intake of water and nutrients

Poisannus h p a w metals mptai? Poisonous heavy mobilized

Sources: m odified a fte r B inns et al. (1985), D u d ley , B a rre tt, an d B aldock (1985), Swedish M inistry o f A g ricu ltu re (1984), an d o th e r sources

102 Acid Rain yellow an d th en brow n. T h e w eak en ed tree soon d ro p s its n eed les and eventually stops grow ing new on es. It becom es bald at th e to p , an d ap p ears stu n te d , sp read in g its b ran ch es o u tw ard an d u pw ard like a sto rk ’s nest. In a d esp era te struggle fo r life, it m ay grow excessive num b ers o f cones o r sp ro u t 'an x iety sh o o ts’ - tiny b ran ch es th a t grow irregularly along th e bough. R o o ts and tru n k s begin to tw ist and shrink. Finally, d ro u g h t, fro st, insects and parasites finish o ff th e w eak en ed plant. In the e n d , it stan d s like a bony finger p o inting tow ard th e sky. (Tifft 1985:46) It was during th e au tu m n o f 1980 th a t G erm an scientists first observ ed the m ysterious w asting disease - th e so-called W aldsterben (m eaning literally ‘d eath o f the tre e s’ o r ‘dying forest sy n d ro m e’) - th a t blighted tre e s and forests. P rofessor U lrich, th e biochem ist who first re p o rted extensive tree dam age in W est G erm an y , a ttrib u te d it to acid d ep o sitio n (U lrich , M ayer, and K hanna 1980) and arg u ed th at unless step s w ere ta k e n to reduce acid deposition dam age w ould escalate and becom e irreversible. U lrich identified th ree stages in th e dam age process (see F igure 5.4) (P earce 1982a): (1) N itrates o r nitrogen oxide in th e acid rain provide n u trien ts to th e soil, th u s trees grow m ore rapidly. T he acid d eposition en d s up in lakes and rivers, leading to fish d eath s. (2) Soils progressively lose th e ir ability to n eutralize th e increased acidity, and acids begin to accum ulate and com bine with o th e r n u trien ts leached out o f th e soil. T his slows dow n tree grow th an d m ay lead to yellowing o f pine needles. S ulphate com bines with m etals in th e soil (especially alum inium ) an d m obilizes th em into toxic solutions. (3) T oxic alum inium is released (at pH 4 .2 ), which leads to destru ctio n o f tree roots an d d ete rio ra tio n o f n atu ral defence m echanism s w ithin the trees th at prev en t th e en try o f b acte ria, fungi, and o th e r viruses. Slow d eath o f the tree th rough starv a tio n , disease, and toxic poisoning ensues. G erm an forests w ere faced with a series o f p ro b lem s, including th e m ystery w asting d isease, increased storm d am ag e, an d reg en eratio n difficulties - all a ttrib u te d e ith e r directly o r indirectly to acid dep o sitio n . W est G erm an forests are believed to receive m ore acid fallout th an S candinavia, being located close to m any large cities and industrial cen tres (such as th e R uh r co rrid o r) with a b u n d a n t em ission sources. T h e speed at which dam age ap p e ared to be spreading was alarm ing. In 1982 only 7.7 p e r cent o f W est G e rm an y ’s 7.4 m illion h ecta res o f forest w ere visibly dam ag ed ; w ithin a y ear 34 p e r cen t o f tree s had suffered discolouration an d som e loss o f needles and leaves; by late 1984 aro u n d half th e co u n try ’s w oodlands show ed sym ptom s o f th e disease (Tifft 1985:47). T able 5.1 show s th a t th e g reatest absolute dam age had been

Effects on soils and vegetation Table 5.1 (a)

Spread o f forest damage in Federal Republic o f Germany, 1982-5

Forest damage by tree species % o f trees damaged

Species Spruce Pine Silver fir Beech Oak Others Total (b)

% of forest area

1982

1983

1984

1985

40 20 2 17 8 13

9 5 60 4 4 4

41 44 75 26 15 17

51 59 87 50 43 31

52 58 87 55 55 31

100

8

34

50

52

Forest damage by category

Category

~ 1982

“

% o f forest area — 1983 1984

1985

1. slightly damaged 2. damaged 3. severely damaged/dead

6 1.5 0.5

25 9 1

33 16 1.5

33 17 2.2

Total

8

34

50

52

Sources: A gren (1984a, b). A non (1986a)

suffered by spruce (over half o f the country’s 1.2 million hectares dam aged by 1984), and the greatest relative dam age had been suffered by silver fir (over 87 per cent of the trees w ere dam aged by 1984) (A gren 1984a: 6). Spruce is the most im portant tree from an econom ic point o f view, and silver fir is 'now regarded as threatened with extinction’ (A gren 1984a) in W est G erm any. T he rapid spread of dam age through previously healthy trees in B aden-W iirttem berg in W est G erm any is clear from Figure 5.5. D uring the early 1980s it was believed th at Waldsterben took betw een two and three years to kill trees, but by 1985 cases w ere being reported in which the effects becam e clear within the bewilderingly short space of five w eeks (Tifft 1985:47). A larm was also expressed at the apparently unselective nature of Waldsterben, which was affecting young saplings as well as m ature trees (firs over 120 years). M oreover, individual trees within forests w ere being affected: 'th e dead trees are usually found isolated in healthier stands. G roups o f dead trees, o r dead forest lots, are very seldom found in W est G erm any’ (A gren 1984b). The disease was also affecting a growing num ber of species (Tifft 1985).

103

Figure 5.5

R apid spread o f dam age to Norway spruce and silver fir trees in the B a d e n -W u rtte m b e rg district of W est G erm an y

1980-4 (a)

N O R W A Y SPRUCE

(b)

a v e r a g e n e e d l e loss in %

a v e r a g e n e e d l e lo ss in %

1980

1981

1981

1982

1982

1983

1983

1984

14

20

23

1980 A

1981 S

19 81 A

D am ag e s t a g e s 2

3

4 A = Autumn

h e a l t h y slig htl y dam age d severely de ad da m a ge d damaged 0-10 11-20 21-60 > 6 0 % ne e dl e loss S o u rc e : N o te :

S I L V E R FIR

S « Spring

a f te r S c h r o t e r (1985) B a s e d o n d a t a f o r 5 5 6 N o r w a y s p ru c e in 17 o b s e r v a ti o n p lo ts , a n d 1,675 s ilv e r fir in 27 p lo ts

31

1982 1982 1983 S A S A

1983 S

1984

Effects on soils and vegetation The first signs of disease were discovered in silver fir (A bies alba) in the early 1970s, but by the late 1970s dam age was also reported in the Norway spruce (Picea abies). By the early 1980s dam age was evident in pine (Pinus silvestris), beech (Fagus sylvatica), and to a m ore limited extent in o ther species such as larch, o ak , red oak, m aple, ash, and rowan (A gren 1984a: 6). The rapid spread o f dam age through species such as oak, beech, and pine during the early 1980s is evident in T able 5.1. A part from the am enity (tourism and recreation) and conservation loss, the large-scale and w idespread dam age to trees has potentially significant financial consequences. Unofficial estim ates o f the cost o f tree death, reduced grow th, and low er-quality tim ber in W est G erm any are in the region D M 7-10 billion per year (A gren 1984a: 7).

DAMAGE SPREADS By the early 1980s Waldsterben appeared to be advancing across E urope, blighting woods in countries including France, Sw itzerland, Sw eden, and Italy. By 1985 over 30,000 hectares of w oodland in France w ere showing signs o f dam age, most seriously in the Vosges and Jura M ountains. T here are two possible explanations for this apparent spread of tree dam age across E urope: that dam age was actually on the increase, o r that observers w ere becom ing m ore aw are of w hat sym ptom s to look for. In reality it is likely that both trends occurred. The ‘b etter aw areness' argum ent certainly holds true for Scandinavia - Swedish foresters only observed dam age effects in 1983 after they had been briefed by the G erm an forest authority (A non 1984a). Eastern E urope has not escaped the ravages of Waldsterben. An estim ated 86 per cent of East G erm any’s 3 million hectares of woodland and 20 per cent of C zechoslovakia’s 960,000 hectares o f w oodland are showing visible signs of dam age (Tifft 1985: 46), and dam age is believed to be evident in Poland, H ungary, and the Soviet U nion (although reported evidence is as yet scanty). D am age has not been confined to E urope, how ever, and there is mounting evidence of sick and dying trees in eastern N orth A m erica. Some of the best U nited States evidence is available for C am el's H um p, a peak forested with red spruce and balsam firs in the G reen M ountains of V erm ont (V ogelm an 1982). R esearch on the changing vegetation of the forest, carricd out at the University of V erm ont, shows that betw een 1965 and 1981 half of the spruce trees had died and seedling production, tree density, and basal area (i.e. tree grow th rates) had fallen by nearly a half. W ood volum e on C am el’s H um p fell considerably after 1965, and it was concluded that ‘if such losses in only a few years are representative of a general decline in forest productivity, the econom ic consequences for the lum ber industry will be staggering' (V ogelm an 1982). C anada, with a $20 billion forest industry, is understandably very concerned over the potential effects of acid rain (see chapter 9). The

106 Acid Rain discovery in 1984 o f su g ar m aple tre es in Q u eb ec P rovince show ing sym ptom s o f severe d ro u g h t (even in th e m idst o f a b u n d a n t m oisture) (Paw lick 1985), which som e ex p erts reg ard as sim ilar to th e evidence o f tree d eath s in E u ro p e a ttrib u ted to acid rain , has d o n e little to allay C anadian fears.

FOREST DAMAGE IN BRITAIN G iven the ap p a re n t sp read o f tree dam age th rough E u ro p e du rin g th e early 1980s, fears began to m o u nt o ver th e p ro sp ect o f acid rain dam age to trees in B ritain. T he official view in B ritain - expressed by th e F orestry C om m ission, and based on th e ir ow n field survey carried o u t in 1984 (B inns et al. 1985) - was th at th ere w as no evidence o f acid rain induced tre e dam age in B ritain. T ests w ere carried o u t on Scots p in e, N orw ay spruce, and Sitka sp ru ce, an d m ost w ere given a clean bill o f health . D r Bill B inns, lead e r o f th e F orestry C om m ission survey, co ncluded th a t ‘B ritish conifer forests reveal no sym ptom s sim ilar to th o se seen in th e d am aged areas o f w estern G erm an y - o r ra th e r, any sim ilar sym ptom s have been aro u n d fo r m any, m any years, and th ere is no dam age th a t can be described as “new " ’ (W .O . B inns re p o rte d in The T im es, 6 A ugust 1984; B inns 1984a). T his state m e n t w as very unconvincing to m any o f B ritain ’s conservationists, given th a t in D ecem b er 1984 W illiam W aldegrave (P arliam entary U n d er-S ecretary o f S tate at th e D o E ) acknow ledged th e existence o f new an d u nexplained dam age to B ritish tre e s (H a n sa rd , W ritten A nsw ers, 20 D ecem b er 1984), and in m id-1984 th e g o v ern m e n t’s ow n Select C om m ittee inquiry into acid rain stressed th e need to confirm recent rep o rts o f dam age to B ritish tre e s th a t seem ed to be sim ilar to th a t observed in W est G erm an y (T h e T im es, 12 Ju n e 1984). M o reo v er, ecologists had been aw are fo r som e tim e th a t coniferous tre es in p arts o f th e P ennines, especially aro u n d M an ch ester (F erguson and L ee 1983; L ines 1984; B ryce-Sm ith 1985), w ere show ing signs o f dam age th a t m ight be related to air p ollution from su lp h u r dioxide, an d recen t a tte m p ts to p lan t conifers th ere had not always been successful. E vidence was also em erging from w oodlands in C am bridgeshire an d Essex and forests in th e L ake D istrict and G allow ay o f ap p a re n t dam age from acidification (P earce 1982b). U nconvinced by th e F orestry C om m ission's conclusion, and incensed by th eir ‘lethargic resp o n se’, F riends o f th e E arth (S cotland) carried out B ritain ’s first survey o f acid rain dam age to tre es during 1984 (A n o n 1984a). It was a partial survey, based on forty-six sites in E n g lan d and on e in so u th ern S cotland, and led by Joachim P uhe o f th e U niversity of G o ttin g en , W est G erm an y . T h e results w ere startling: th irty -o n e o f the sites show ed signs o f dam age to conifers and hard w o o d s, and a range of species w ere affected (D ouglas fir, N orw ay and Sitka sp ru ce, b eech , and pine). T h e m ost acu te dam age was o b serv ed in th e L ake D istrict (advanced needle loss on Sitka spruce aro u n d W h in latter Pass) an d in th e F o rest o f

Effects on soils and vegetation D ean n e a r A v o n m o u th (canopy loss, b ran ch d efo rm atio n , and loss of leaves on beech). F oE (S cotland) im m ediately called fo r an u rgent and com prehensive tre e survey to ev alu ate th e e x te n t o f dam age and p o ten tial loss o f forest revenue. T his w as to be the sta rt o f a prolo n g ed series of exchanges o f rhetoric betw een F o E and th e F orestry C om m ission, b o th of w hom challenge each o th e r’s results. C onscious o f th e need to study British tre e dam age in m uch g rea te r d etail, and to have ex p ert guidance and at th e sam e tim e to m axim ize possible m edia ex p o su re, F riends o f th e E arth (w ith W orld W ildlife Fund sponsorship) flew in Swedish forest ecologist D r B engt N ihlgard in early A ugust 1985 ( The T im es, 15 A u gust 1985). N ihlgard found signs o f dam age to sev enteen B ritish tre e species (especially d eciduous ones) from eight counties, com parable to , if n o t w orse th a n , w hat he had seen in Sw eden and n o rth ern and cen tral E u ro p e. Yew trees w ere fo und w ith c h aracteristic yellow ing and early needle loss (the so-called ‘tinsel sy n d ro m e’); beech show ed typical reduced crow n gro w th , pale yellow leaves, and early leaf d ro p ; som e N orw ay spruce had high (over 50 p er cen t) needle loss, com parable to th at seen in th e w orst-hit p arts o f E u ro p e (A n o n 1985). O n 15 A ugust 1985 th e first national survey o f acid rain dam age to native B ritish trees was launched by Friends o f th e E a rth . T he n ational survey, also funded by the U K W orld W ildlife Fund, was inspired by th e findings of th e earlier partial survey and th e results of N ih lg ard ’s visit. T h e b rief - to exam ine dam age to yew and beech tre es th a t might stem from acid rain was p rep ared because en v iro n m en tal groups believed th a t official denial of dam age to young forestry p lan tatio n s overlo o k ed w idespread dieback in o ld er native trees and hedgerow s (A n o n 1985). T he 1985 F oE survey w as a direct challenge to the official B ritish opinion th a t native trees w ere not being adversely affected by acid rain. T h e F orestry C om m ission w ere quick to seek to underm ine th e basis o f th e FoE claim , pointing o u t th a t th eir own (1984) survey o f d eciduous tre es in the N ew F orest found no evidence of air p ollution dam age. B inns stressed th at ‘th e dam age do n e to tre e s by the droughts o f 1976, 1983 and 1984 still show s. T h at m ay be th e reason for the confusion’ ( The T im es, 23 A ugust 1985). By late A ugust 1985 th e re was clear evidence o f tree dam age to deciduous (especially beech ) tre e s in B ritain. N eith er p arty d o u b te d that the evidence existed, but in te rp re tatio n s d iffered. T h e F orestry C om m is­ sion blam ed clim atic factors (especially the legacy o f th e 1976 d ro u g h t) and F oE blam ed acid rain. A nxious to avoid a ‘w ar o f w ords’ w ith F riends o f the E a rth , the F orestry C om m ission agreed to carry o u t a m ore detailed sam ple survey o f beech trees {The T im es, 26 A u gust 1985). T en tativ e results o f the survey w ere released in S ep tem b er 1985, and suggested no significant link with acid rain. T h e C om m ission insisted th a t observed dam age could be a ttrib u te d to d ro u g h t, fungi, o r insects (F orestry C om m ission 1985; R ose 1985). T h e results o f th e F o E Tree D ieback Survey w ere published on 6 O cto b er 1985, and w ere in te rp re te d as clear signs o f acid rain d am ag e to

108 Acid Rain beech and yew trees in England and W ales. O nly one-third o f the 3,184 beech and yew trees exam ined at 799 sites in 49 counties w ere considered to be healthy, ten o th er species (including fir, o ak , spruce, and pine) w ere found to be at risk, and dam age sim ilar to that blam ed on acid rain in E urope was found to be w idespread. T he survey described in graphic detail the ‘death of an ancient yew’, in four stages ( The Tim es, 1 N ovem ber 1985): (1) T he tree is in good health, with green needles. (2) Patches of thinning ap p ear on the tree, o lder needles (fu rth er up the twig) often turn yellow then dro p off. The tree is covered with ragged, drooping twigs (the so-called ‘tinsel syndrom e’). (3) M ain branches becom e visible within the tree as needle loss intensifies, tinsel syndrom e causes a ‘net cu rtain ’ effect, the canopy is sem i­ transparent and casts little shade (plants can now establish them selves beneath the tree). (4) The tree is m oribund, branches have a mossy appearance, the tree silhouette is skeletal. Friends o f the E arth claim ed, proudly and defiantly, th at ‘we think it shows that acid rain dam age has definitely arrived in B ritain’ (C hris R ose, reported in The Times, 7 O ctober 1985). Professional foresters in B ritain insistent that observed effects were com patible with drought dam age w ere not convinced, and accused F oE of publishing a ‘scarem ongering’ rep o rt, based on ‘am ateurish founderings’, which ‘achieved nothing but publicity’ (correspondence from D r B. N. Howell to The Tim es, 17 O ctober 1985). T he tree dam age debate in B ritain has quietened dow n som ew hat since late 1985, but many ecologists and environm ental groups are m onitoring woods and forests in search for m ore conclusive evidence of the effects of acid deposition on both deciduous and coniferous trees. In the final analysis, the two sides in the debate are not necessarily forw arding m utually exclusive o r diam etrically opposed interpretations, because it is quite possible (if not likely) that British tree dam age is being caused by climatic effects on trees with reduced resistance as a consequence o f acid dam age.

COMPLEXITY OF FOREST DAMAGE T here is now little doubt that a growing num ber of individual trees and even whole forests are dying, especially in E urope. V arious explanations have been offered for such w idespread dam age, and the most convincing evidence points to air pollution - and especially to acid deposition - as a prim e catalyst. T he consensus view is now em erging am ongst many E uropean and N orth A m erican scientists th at, even if air pollution is not the only factor involved, tree dam age and d eath are unlikely on such a large scale w ithout air pollution. T rees are attacked by acid deposition on

Effects on soils and vegetation many fronts (see Figure 5.4), and ‘w hen death com es, it is often due to natural causes - insects, high w inds, frost and drought. M uch like an A ID S victim whose im m une system has broken dow n, the ailing tree is left defenseless against the ravages o f n a tu re ’ (Tifft 1985: 47). T he evidence suggests that the dam age is caused by acid deposition from air pollution in com bination with a whole host of contributory factors (Lesinski 1983:158; T olba 1983:117; R ibault 1984; Blank 1985). These include: • • • • • • • • • • •

the dry fallout of S 0 2 and N O x ozone heavy metals parasites and plant diseases extrem e climatic conditions (very high and very low rainfall, tem pera­ ture extrem es - especially frost) forest m anagem ent practices (e.g. forest fire prevention in some areas has kept alkaline ash from neutralizing som e acid-polluted soils) site factors (such as soil drainage) the nature of underlying soil the general state of health (and age) of the trees involved surges of naturally produced acids acid flushes (e.g. during spring snow melt o r after prolonged drought).

T here is growing interest in the possibility that ozone might be a more likely cause of tree dam age than acid deposition, through increasing the vulnerability o f individual trees to poisoning and loss o f nutrients (Skeffington and R oberts 1985; The Times, 8 May 1986). M oreover, some research suggests that increased ozone m akes trees m ore vulnerable to acid-induced dam age. O zone might play a significant role, especially at high altitudes w here sunshine (required for the photo-chem ical processes that produce the ozone) is m ore intense. Many of the dam aged trees in W est G erm any and elsew here are found above the 10,000-foot line, in rem ote areas of forest som e way away from obvious centres of pollution (A shm ore, Bell, and R u tter 1985; Tifft 1985:47), suggesting that ozone may be not only involved but perhaps of som e significance.

Puzzles and problems Many key problem s and areas of uncertainty rem ain as yet only partially resolved. Part o f the variability of response arises because much dam age may rem ain undetected or invisible until it reaches a critical, perhaps irreversible stage. D ifferent species have different dose-response rela­ tionships, so they respond to changing levels o f acid input in different ways. F urther variability arises because dam age to vegetation tends to be species specific, so that different plant species react to a given level of acidification in different ways. F u rth erm o re, not all individuals of a given

109

110 Acid Rain species are equally sensitive to pollution stress. G enetic variability gives rise to variability in response to S O i and ozone in populations o f Scots pine, Norway spruce, and o th er coniferous (and som e species of deciduous) trees, for exam ple (Lesinski 1983). M oreover, much dam age to vegetation is location specific (BuckleyG older 1985). Thus one forest might show signs o f dam age from acid deposition whilst a neighbouring one (perhaps underlain by different soils o r bedrock, with different buffer capacities) might not. T o com plicate m atters even fu rth er, synergistic (com pound) effects (see chapter 3) are often apparent. M ixtures o f S 0 2, N O x and 0 3 occurring together appear to have a far g reater effect than each gas acting on its own (B uckley-G older 1985). O ne particular puzzle is why lichens, which are very intolerant o f S 0 2 pollution, still exist in som e w oodlands w here tree dam age and death have been attributed to acid deposition. The reverse side o f the sam e coin is the puzzling lack o f reports of tree dam age and death in heavily polluted city centres from which lichens have long since disappeared (B enarie 1985). This again suggests that ozone may play a m ore critical role than some scientists have hitherto thought likely. ‘A cid rain’ is a strange and variable brew o f pollutants (see chapter 2), and the variable com position/character of the m ixture through tim e and from place to place adds a fu rther veneer o f com plexity to an already highly variable family o f responses by vegetation. T he net effect of all these problem s is extrem e difficulty in disentangling possible causal o r contribu­ tory factors. T he air o f mystery persists.

CROP DAMAGE W e have concentrated in this chapter on effects of acidification on trees and forests. This focus is ap p ro p riate, given the evidence o f serious dam age in many areas and the correspondingly high interest of conserva­ tionists in the problem . H ow ever, we should not overlook the possible effects of acidification on o th er form s o f vegetation, most especially on agricultural crops. Sulphur dioxide and wet deposition of acids affect all higher plants, eith er in reduced grow th o r in physical dam age (both result in reduced crop yields). It has been estim ated (Elsw orth 1984a) that acid rain has destroyed up to £25 million w orth o f crops in parts o f C um bria and Scotland - the areas of B ritain th a t now receive the highest atm ospheric inputs o f acids (see chapter 1). Fears have also been expressed th at acid rain might be cutting crop yields in Britain by as much as 10 per cent, costing the nation's farm ers in the region o f £200 million each year (M. U nsw orth, q u o ted in A cid N ews, 1984, 2). F arm ers m eet part o f the cost o f acid rain via increased need to add lime to acid soils, as well as through reduced crop and livestock yields (Figure 5.6). A s yet, how ever, there is no conclusive evidence of actual crop dam age

Effects on soils and vegetation Figure 5.6

Effects of acid rain on farming [ a c id r a i n

WET DEPOSITION

] DRY DEPOSITION

caused by acid rain, and lab o rato ry tests have yielded m ixed results: som e have show n reductions in crop yield, som e have show n increases, and som e have show n no n et change (L a Bastille 1981:672-3; R o b e rts et al. 1983; R o b erts 1984). P art o f th e variability m ight stem from th e fact th a t sulphur and nitrogen can act as plan t n u trien ts, ra th e r th an dam aging p ollutants. B elow critical threshold s an d in th e sh o rt te rm , acid d eposition can be an asset in providing lim iting n u trien ts (especially nitro g en ) and hence prom oting p lan t grow th (increasing forest p roductivity). L ab o rato ry studies have show n th a t, at low co n cen tratio n s, S 0 2 p ollution (o r fum igation) stim ulates th e assim ilation o f C 0 2 by plan ts, and th u s it assists p lan t grow th (L esinski 1983). M ost dam age ap p ears to stem from quite subtle indirect effects o f w et and dry deposition. T he tw o prim ary causes o f indirect effects are the changing am ounts o f available plant n u trien ts in the plan t and soil system , and the m obilization o f com p o u n d s (e.g. heavy m etals) th a t are toxic to plants. B oth involve in teractio n s betw een p lan t and soil, so th at acidifica­ tion o f soils is o f critical im portance.

TREES AS POLLUTION FILTERS T he association betw een plants and a ir pollution is sym biotic (tw o-w ay). A ir pollution affects p lan ts, directly and indirectly, generally for th e w orse. But plants also affect air po llu tio n , generally for th e b e tte r. T rees, in particular, o p erate as n atu ral air filters th a t rem ove (scavenge) p o llutants from the atm osphere an d thus im prove air q uality. F orests act as 'pollution sinks’ in tw o m ain ways - as air filters (grim e th at collects on the leaves o f trees is rem oved from circulation in th e atm o sp h ere ) and as air v entilators (trees cause air cu rren ts and eddies that help to ventilate an area th a t m ight otherw ise have very still air) (M abey 1974: 99). C oniferous trees are p articularly effective in filtering o u t gaseous p ollutants from overying air (H arrim an and M orrison 1981; Last and

111

112 Acid Rain N icholson 1982), alth o u g h this is a ra th e r m ixed blessing. T h e g o o d new s is th a t th e trees act as filters, scavenging noxious p articles from th e overlying air. T h e bad new s is th a t th e tre e s an d underlying soils ab so rb th e toxic m aterials th at are scavenged. T his m eans th a t the tre e s them selves can increase th e acidity o f rainfall (i.e. enrich it) w ithin th e fo rest. A fte r heavy rain th e sulphur particles th a t have collected (dry) on conifer n eedles are w ashed o ff on to underlying soils and into a d jac e n t stream s an d lakes. C oniferous trees can also in tercep t acid m ists (occult p recip itatio n - see ch a p te r 2) th a t m ight o therw ise have p assed o v er an a re a w ith o u t allow ing deposition o f acids, a process th at can fu rth e r en h an ce th e acidity o f throughfall b en eath th e forest canopy (B u ck ley -G o ld er 1985). B ecause o f this sym biotic link betw een trees and p o llu tio n , th e re are quite com pelling env iro n m en tal g rounds for concluding th a t a policy o f planting conifers in B ritain ’s m arginal uplands (see c h ap te r 3) m ust be seen very m uch as a m ixed blessing.

CONCLUSIONS A s with surface w aters (ch a p te r 4 ), we em erge w ith th e conclusion th a t, whilst it is difficult to find unequivocal evidence fo r o r against th e proposition that acid d eposition causes unacceptable dam age to soils, trees, and crops, th e circum stantial evidence is stro n g and convincing. T he possible im pacts are b o th biological and econom ic. Biological effects are reflected in tre e d ieb ack , red u ced p roductivity, falling crop yields, contam in atio n o f crops with heavy m etals, and so on. B ut th e econom ic dim ension is also very real. T he decline in tree p roductivity is directly tran slate d into a red u ced supply o f tim b er (h en ce incom e from fo restry ), and th e decline in crop yields is a serious com m ercial blow for th e farm er. B oth also p roduce m arket sh o rtag es th a t enco u rag e price rises, so th at consum ers also pay th e cost o f acidification. M any uncertain ties su rro u n d any evalu atio n o f th e effects o f acid rain on forests and soils, not least o f which is th e fact th a t th e biological effects o f acidification change as acid co n cen tratio n increases. A t low c o n ce n tra­ tions, dry an d /o r w et fallout can p rovide valuable free n u trien ts to plan ts, especially in nutrien t-d eficien t soils. B ut at higher co n cen tratio n s (an d th e critical threshold varies from species to species, and from area to area d epending on buffer capacities) d irect dam age to plants m ight be ex p ected . T his can tak e various form s, from reduced rates o f grow th to severe physical distortio n and disfigurem ent (especially in trees). A d d ed com plex­ ity com es from th e fact th a t re p o rte d d am ag e, to trees in p artic u la r, is w idely scattered - even w ithin one forest. D am age is n o t ubiqu itou s. T his might im ply th a t differen t explan atio ns are req u ired for d ifferen t areas. In d eed , som e scientists stress th at it is as difficult to explain why acid deposition has no t affected som e a reas, as it is to explain why it has affected o th ers.

Effects on soils and vegetation M any scientists have w arned th at unless d rastic action is tak en w ithout delay, large tracts o f E u ro p e ’s forests m ay be red u ced to b a rre n w astes by th e tu rn o f th e century (H alfo rd 1986). W holesale loss o f fo rests w ould th reaten the forestry and tim b er industries in E u ro p e , which provide m uch-needed raw m aterials an d m any jo b s. T ourism could also be affected, w ith im plications fo r em ploym ent and local econom ies. T h e sort o f action th a t is being w idely called fo r cen tres on reducing em issions (m ainly o f S 0 2, b u t also N O x) from pow er statio n s, factories, houses, and vehicles in o rd e r to reduce th e p o ten tial fo r p roducing acid deposition. A s we shall see in th e next c h a p te r, sim ilar calls are also being m ade by those w ho are co n cern ed a b o u t the possible dam age caused by acid rain to buildings and to hum ans.

6 EFFECTS ON BUILDINGS AND HUMANS Palaces and p e o p le . . .

It is a reveren d thing to see an ancient castle o r building not in decay. (F rancis B aco n , The Elem ents o f C o m m o n L aw , V olum e 14, O f N obility) M ost o f th e im m ediate controversy su rro u n d in g th e im pacts o f acid rain has cen tred on lakes and rivers, an d on forests and crops. T his focus o f concern is easy to u n d erstan d , given th e m ounting evidence o f biological dam age in S candinavia, W est G erm an y , B ritain, C an a d a , and th e U n ited S tates. W hilst th e n atu ral history and conservation in terest has o v e r­ shadow ed scientific concern o v er o th e r u nw anted im pacts, at least in term s o f m edia coverage and g eneral public aw areness, th e la tte r a re proving to be both real and significant. T hey are also proving to be costly. A recen t O E C D estim ate put th e cost o f dam age to buildings in W estern E u ro p e from industrial air pollution at aro u n d $3.5 billion p e r y ear, an d th e cost to hum an h ealth at a fu rth e r $8 billion p er y ear {The Tim es, 19 N ovem ber 1985, p. 16). Im pacts on buildings and h um ans have n o t (o r p erh ap s n o t yet) figured m ore prom inently in th e ‘acid rain d e b a te ’ largely because they affect sm aller areas (large cities and industrial areas) an d th e dam age a p p ea rs to be related m ore to dry d eposition (oxides, gases, and p articles) th an to w et deposition. M ost concern in the d e b a te has focused on th e long-range (especially th e tran s-n atio n al) effects o f w et d eposition - acid rain in the tru e sense. F orests and lakes a re being affected by acidification in th e co untryside; buildings and stru ctu res are being affected in th e cities. W e shall exam ine effects on m aterials an d buildings and effects on hum an h ealth in this ch ap ter.

EFFECTS ON MATERIALS AND BUILDINGS A ir pollution attack s sto n e , m etals, and fabrics, an d th e re is no sh o rtag e o f evidence o f th e dam aging effects o f m any form s o f a ir p o llution on buildings and stru ctu res. A cid depo sitio n (w et an d dry) is widely im plicated as th e m ost serious cause o f th e dam age.

Effects on buildings and humans T h e problem is vividly illu strated in C racow , P o lan d ’s m ajo r city, regard ed as having one o f th e w o rld ’s w orst pollution p ro b lem s, which receives acid deposition from upw ind K atow ice (a heavy industrial area ); ‘as a result C racow is crum bling. T he golden ro o f o f th e church had to be rem oved because it was dissolving. T he faces o f th e statu es are m elting. S teeples are falling dow n , balconies d isin teg ratin g ’ (M ay 1982: 9).

Perspective on the problem U rb an air pollution is n o t a new p h en o m en o n . In 1661, for exam ple, the n oted p hilanthropist Jo h n Evelyn su b m itted his text ‘Fum ifugium , o r the Sm oake o f L ondon D issip ated ’ to K ing C h arles II. H e w rote o f early seventeen th -cen tu ry L o n d o n , w hilst these [chim neys] a re belching fo rth th eir sooty jaw s, th e city o f L ondon resem bles th e face ra th e r o f M o unt E tn a . . . . o r th e suburbs o f hell, than an assem bly o f ratio n al creatu re s, an d th e Im perial Seat o f o u r Incom parable M onarch . . . . T h e w eary trav eller, at m any miles d istance, so o n er sm ells th an sees th e city to which he repairs. T his is that pernicious sm oke which foils all h er G lo ry , superinducing a sooty crust o r fur upon all th a t it lights. (q u o te d in T hom pson 1978: 6) N either is the problem o f building dam age from air p ollution new , o r newly discovered. A s far back as 1852, R o b e rt Sm ith (th e g ran d fath er o f acid rain studies, m entioned in ch ap te r 1) rep o rte d to th e C hem ical Society: it has often been observ ed th a t th e stones and bricks o f buildings, especially u n d er projectin g p arts, crum ble m ore readily in large tow ns, w here m uch coal is b u rn t, then elsew here. A lthough this is not sufficient to prove an evil o f th e highest m ag n itu d e, it is still w orthy o f ob servation, first as a fact, an d next as affecting th e value o f p ro p erty . I w as led to a ttrib u te this effect to th e slow but constant action o f th e acid rain. (Sm ith 1852) W hat is new is th e grow ing seriousness o f th e p ro b lem . A s S 0 2 co n centrations in the atm o sp h ere continue to rise, and acid deposition becom es a g re a te r and m ore w idespread p ro b lem , dam age to buildings and m aterials gets w orse an d m ore w idespread. H istoric m aterials o ffer a valuable basis fo r ch arting the progress of dam age through tim e. F o r exam ple th e Elgin M arbles, which w ere tran sp o rted from th e A cropolis in R o m e to th e B ritish M useum in L ondon in th e late eig h teen th c en tu ry , are well p reserved in th e clean m useum air, w hereas sculptures o f a sim ilar age th a t rem ain ed in situ in R o m e have since d eterio rated badly in th e pollu ted u rb an air (M cC orm ick 1985). It is generally believed th a t air pollution has caused m ore d e te rio ra tio n of ancient statu es in R om e since 1950 than had occu rred in th e previous 2,000 years (G ates 1972).

116 Acid Rain Corrosion of materials A ir pollution speeds the natural chem ical w eathering and corrosion of exposed m aterials in a variety o f ways. For exam ple, ferrous m etals are attacked by sulphur oxides, iron rusts m ore quickly, and zinc products are m ore badly corroded in urban areas. Sulphur oxides etch th e surface o f the m etals, and when iron rusts the surface becom es flaky and the flakes fall off to expose m ore m etal to the etching process. C onsequently steel buildings, railway rails and o th er structures built of iron can be very seriously affected by air pollution, with extensive econom ic losses (Lynn 1976; A non 1984/5d). N on-ferrous m etals corrode much less, because the oxides and sulphates rem ain on the surface and offer protection to the m etal below. E xperim ental tests show th at many m aterials corrode faster in polluted urban and industrial air (particularly in the presence o f high concentrations o f sulphur dioxide) than they do in the countryside: corrosion rates are com m only betw een two and ten tim es as fast (Tolba 1983:118). C orrosion rates are often speeded up even m ore in the presence o f m oisture and carbon soot and with high tem peratures; hence corrosion tests in Sweden have shown that carbon steel is corroded fifteen tim es faster in Stockholm 's polluted urban air than in a rural sub-arctic area (with low tem peratures and low S 0 2 and sulphate levels) (Perkins 1974). C orrosion tests tend to show only m arginal effects o f air pollution on m aterials like alum inium and stainless steel. T hus air pollution speeds rates o f deterioration and accelerates the spread o f dam age in m aterials like carbon steel (coated and uncoated), painted steel, galvanized steel, copper, nickel, and nickel-plated steel. C onsequently item s m ade o f these m aterials are at risk from acid deposition, particularly in the dry form (gases, oxides, and particles of sulphur). T hus, for exam ple, cars and o th er road vehicles are believed to corrode faster in m ajor cities than in the countryside (G re a ter London Council 1985: 17), with corresponding econom ic im plications for their owners! Similarly, electrical devices containing copper, silver, and gold contacts are m ore at risk from corrosion in heavily polluted areas; silver used in electrical contacts in telephone exchanges often has to be p rotected from tarnishing (G re ate r London Council 1985: 17). Sulphur oxides are only one com ponent of air pollution in many cities; o th er com ponents can also produce dam aging effects. F or instance, ozone has long been known to cause dam age to ru b b er, mainly by increasing cracking and thus speeding d eterioration. T here is a belief that the high levels of oxidants and ozone in the air of Los A ngeles (caused by exhaust emissions) seriously reduces the life o f ru b b er tyres (Strauss and M ainwaring 1984). T he vehicle ow ners also pay for air pollution in increased running costs! It has also been found th a t, when ru b b er tyres w ere stacked in w arehouses in Los A ngeles, the tyres on the bottom often cracked (by ground-level ozone concentrations) during storage (Carr 1965).

Effects on buildings and humans A ir pollution can also dam age p ain t coatings. S unlight norm ally causes m ost direct dam age to p ain tw o rk , b u t rates o f d e te rio ra tio n sp eed up considerably in the presence o f su lp h u r d ioxide, o zo n e, an d p articu lates (G re a te r L ondon C ouncil 1985). T his not only spoils visible ap p earan ces throug h d iscolouration, it fails to provide p ro p e r w eath e r proofing so th at underlying m aterials are th en directly exposed to th e ravages o f w eath er and pollution. T h e re is som e evidence to suggest th at intervals betw een repainting tend to be sh o rte r in u rb an areas than in th e countryside (G re a te r L ondon C ouncil 1985), b u t this m ight n e t just reflect observed differences in air quality. If surface and groun d w aters are affected by acidification, subm erged structures m ay be co rro d ed . T his m ight affect a m uch w ider a re a th an the im m ediate vicinity o f u rb an and industrial cen tres. T h u s bridges, dam s, industrial eq u ip m en t, w ater supply netw orks, u n d erg ro u n d storage tanks, and hydro-electric tu rb in es o v er a wide area can also be seriously affected by acid deposition (T olba 1983).

Damage to buildings T he g reatest concern o v er effects o f acid rain on m aterials has cen tred on dam age to buildings, especially those b uilt o f san d sto n e, lim estone, and m arble. R ates o f decay and dam age to stone in urban areas a re o ften two to th ree tim es as high as in rural areas (W in k ler 1970) because of accelerated w eathering from air p o llution. B oth th e stone and th e m o rtar o f buildings can be affected , and dry d eposition a p p ears to be th e principal dam aging agent. P ollutan ts are norm ally o f local origin. L im estone buildings and stru ctu res are norm ally w orst affected. D ry d eposited sulphur reacts with th e calcium carb o n ate in th e p resence of m oisture to form calcium su lp h ate. T his is soluble, and the acids so form ed are w ashed off th e surface o f th e sto n e w hen it next rains (B o ttam 1966; G re a te r L ondon C ouncil 1985). T his cycle o f dry d e p o sitio n -re a c tio n w ashing is rep eated m any tim es, and greatly speeds th e n atu ral w eathering and erosion o f the building fabric. B u t th e re is also a n o th e r process at w ork (Fassina 1978). T h e soluble su lp h ates, n itrates, ch loride an d o th e r salts th at are w ashed across th e surface o f th e stonew ork will crystallize within the stone w hen th e w ater e v ap o rates off. A s th ey tu rn into crystals, the salts expand an d this force enlarges th e cracks; this leads to a crum bling (exfoliation) o f the ston e surface, which in turn exposes u n w eath ered stone b en eath to the cycle o f d ry d ep o sitio n -re a ctio n -w a sh in g (D u n m o re 1986). In w inter, m oisture can also p e n e tra te th e cracks, and th en freeze, ex p an d , and cause fu rth er flaking. C hem ical corrosion causes all types o f lim estone to pow der, crum ble, flak e, crack , o r chip. T he direct roles in such erosion played by w et acid deposition and by dry d eposition o f n itrogen oxides are as yet n o t fully u n d ersto o d o r q uantified. D ifferent building m aterials are affected to differen t ex ten ts. W orst affected are lim estones and d olom ite. B ut since (as we shall see in

118 Acid Rain ch a p te r 7) on e o f th e p ro p o sed clean-up tech n iq u es fo r S 0 2 in po w er station em issions is to react it w ith lim e, it should com e as n o surprise to find th a t th e sam e chem ical reaction tak es place in n atu re (P erk in s 1974)! Sim ilarly cem en t (w hich has a high lime co n te n t) can b e seriously w eakened by S 0 2. In c o n tra st, san d sto n e, which is com posed m ainly of silica, is relatively unaffected by S 0 2; th e m ain visible effect is to p ro d u ce a h ard , black surface coating on exposed san d sto n es. G ran ite also blackens ra th e r than crum bles. O ne com m on effect o f acid d eposition is to discolour building m aterials and paintw ork. T his staining by su lp h u r p o llu tan ts is especially visible in industrial cities w here initially light-coloured sto n es an d bricks soon becom e dark and blackened. Such ‘d am ag e’ has a clear econom ic im plication via th e need for reg u lar and costly cleaning, rep air, and renovation w orks. B rick-built stru ctu res are less v ulnerable to air pollu tio n dam age th an stone-built structu res. A s a resu lt, relatively few recen t (brick-built) buildings face serious erosion p ro b lem s, b u t a g reat m any (sto n e-b u ilt) historic m o num en ts and buildings do. Som e o f E u ro p e 's finest G o th ic (tw elfth to sixteenth cen tu ry ) cath ed rals are show ing such serious signs of dam age an d d ete rio ra tio n th a t som e ex p erts fear th a t - w ithout m arked reductions in local u rb an air pollution - they m ight n o t survive fo r m ore than a b o u t tw o m ore cen tu ries (S trauss and M ainw aring 1984). T h e re is little d o u b t th a t m ost o f th e dam age is recen t: ‘co m parisons with old records still in existence reveal th a t th e 150 years since th e beginning o f the Industrial R evolution have caused m ore dam age th an o ccu rred in all th e previous cen tu rie s’ (L ynn 1976: 145). In som e cou n tries (especially B ritain and th e U n ited S tates) it is b elieved th a t rates o f erosion o f building m aterials may have slow ed dow n in recent years, reflecting red u ctio n s in S 0 2 levels because o f C lean A ir A cts. B ut th ere are signs th a t th ere m ay be delays betw een em ission and d am ag e, thus delays m ight be ex p ected betw een reduced em issions and red u ced erosion. It has been suggested th at m ost stone d ete rio ratio n now ev id en t is m ainly the result o f dry d eposition o f S 0 2 from th e years b efo re th e C lean A ir A cts w ere passed (th e early 1960s), ra th e r th an from c u rre n t industrial em issions (R idley 1985). T his suggests th a t we should p erh ap s be th in k in g o f an ‘acid tim e b o m b ’ - th e effects o f w hich m ight lie d o rm a n t fo r som e tim e, accum ulating to a serious level before visible evidence sta rts to ap p ear.

Erosion of the cultural heritage T h ere are grow ing concerns a bo u t th e ex ten t o f visible dam age now being caused by air p ollution to th e w o rld ’s cu ltu ral h eritag e - ancient m o n u m en ts, historic buildings, scu lp tu res, o rn a m e n ts, an d o th e r im p o r­ tan t cultural o bjects. T he catalogue o f significant casualties grow s longer each year. T h e follow ing discussion is not in ten d ed to be exhaustive; it

Effects on buildings and humans offers a selection o f the best (o r, to be m ore correct, w orst) examples. M any o f E u ro p e’s most cherished cultural treasures are housed in A thens in G reece. Y et all is not well there. Acid precipitation (wet and dry) has increased dram atically over the present century with the increased emission o f oxides from industry, vehicles, and dom estic heating systems. M any o f the city’s most fam ous artefacts are paying the toll. T he stonew ork of the A cropolis is believed to have crum bled m ore during the past forty years than it had done over the previous 2,500 years (Strauss and M ainwaring 1984). The P arthenon has suffered so much dam age from air pollution that som e official reports predict it might fall down com pletely w ithout extensive (and costly) repair w ork (Thom son 1969). Italy vies with G reece as a cultural centre; it is also faced with similar problem s from air pollution. In R om e, T ra ja n 's C olum n and M ichelange­ lo’s Statue of E m peror M arcus A urelius have been badly dam aged (the latter had to be rem oved because o f m etal corrosion) (M ay 1982: 9). Many of the finest palaces and m onum ents in Venice are also being attacked by dry deposition of pollutants, particularly ‘oil-fired [acid] carbonaceous particles [which] are am ong the main agents responsible for stone w eathering’ (C am uffo, M oule, and O ngaro 1984: 135). In many o f Italy’s m ajor cities, sulphur dioxide has dam aged frescos m ade o f pigm ented lime plaster; the plaster is changed to gypsum , and in the process it shrinks in volum e and loses its coherence (Thom son 1969). C rum bling fragm ents are all that rem ain of som e o f the country's finest artistic and cultural heritage; no am ount of m oney can replace them . D am age is not restricted to m ajor cultural o r tourist centres. In the N etherlands, for exam ple, air pollution has caused serious dam age to statues and o th er decorations outside the 457-year-old’s H ertogenbosch Saint Jo h n ’s C athedral. A m sterdam 's Royal Palace on D am Square and the nearby Rijksm useum are also suffering from black encrustations (‘stone cancer') caused by S 0 2 in the air (H oyle 1982). Sw eden, already incensed at the loss o f fish stocks in many rivers from acidification arguably im ported from abroad (see ch ap ter 4), is also faced with the ignominy of producing its own urban pollution that affects buildings and treasures. Stockholm ’s thirteenth-century R iddarholm C hurch had a cast-iron spire that was so badly corroded by acid rain that it had to be replaced in the 1960s; the church's sandstone Royal Burial C hapel is now being seriously dam aged by air pollution (H oyle 1982). N either is dam age confined to E urope. In India, the Taj M ahal has been a ‘jew el in the crow n’ o f grand architecture and a valuable tourist attraction. But sulphur pollution from pow er stations at A gra and a large oil refinery at M althura has brought many problem s to the building, including discolouration, flaking of sandstone, and blistering of many of the precious stones set in to the walls (M ay 1982: 9). D elhi’s R ed Fort and Jam a M asjid are also showing signs o f dam age from sulphur pollution, in a city that has experienced a 75 p er cent increase in air pollution since the mid-1970s (D u tt 1984).

120 Acid Rain T h e U n ited S tates, a cou n try with a b rie f if ra th e r ev entful ‘h istory’, none the less has its fair share o f dam age to buildings and stru ctu res. C le o p a tra ’s N eed le, a g ran d stone obelisk tra n sp o rted from E gypt to N ew Y ork in th e 1860s, provides a m easure o f how fast pollu tio n -accelerated dam age can be. T h e colum n was originally erec te d by th e N ile opp o site C airo , aro u n d 1500 B C ; all o f its inscriptions w ere in good condition w hen it left E gypt. T o d ay , legible hieroglyphic inscriptions survive on th e east side o f th e colum n, b u t th e w est side (facing prevailing w inds) has been e ro d ed alm ost flat (M ay 1982: 9). T his sim ple visible evidence show s th at ninety years in New Y ork have d o n e m ore dam age to th e m o n u m en t than 3.500 years in E gypt had d one. N ew Y o rk ’s fam ed S tatu e o f L iberty adm ittedly m etal ra th e r than stone - c e le b rated its h u n d red th b irthday in July 1986 (Stengel 1986) only after a massive (and costly) rep air and ren o v atio n jo b . L o n d o n , E n glan d , has long been on e o f th e w orld’s cu ltu ral cen tre s, and - as n o ted in ch a p te r 1 - it has long p ro d u ced an d suffered from air pollution. It has also p rovided som e m o n u m en tal exam ples o f building dam age. T he H ouses o f P arliam ent need reg u lar rep airs to th e sto n ew o rk , partly because of dam age caused by air p ollu tio n (O rm e ro d 1983); ex tern al repairs carried o u t in 1983/4 alone cost £624,000. A lso in L o n d o n , o n e o f fo u r bronze statu es had to be rem oved from th e R oyal A rtillery M em orial (com pleted in 1925) at H yde P ark C o rn e r late in 1984 fo r cleaning, at a cost o f a ro u n d £30,000, because acid rain had c o rro d ed its iron an d steel fixings and w as destroying th e su pportive relief carvings in soft P o rtlan d stone (T h e Tim es, 10 O cto b er 1984). C h risto p h er W ren sta rte d to build St P au l’s C a th e d ra l in 1675. B ut in 1717 a decision w as tak en to add a b a lu stra d e , an d this w as d o n e th e next year. W hen th e b alu strad e was built, th e jo in ts betw een and lifting holes w ithin th e P o rtlan d lim estone blocks w ere filled (flush w ith th e stone surface) with lead. T h e stonew ork has been e ro d e d by air p o llu tio n , th e lead has no t, so th e difference in height betw een sto n e an d lead gives a m easure o f rates o f stone erosion. B etw een 1718 and 1980 th e sto n e was being w orn dow n at a rate o f aro u n d 8 mm p e r 100 years (a ro u n d 20 mm ov er the 250 years). D etailed m easu rem en ts o f p resen t-d ay rates a re in th e range 5.8 -3 1 .9 m m p e r 100 years (S harp et al. 1982), an d o v e r tw o-thirds o f the estim ated total sto n e loss on exposed p arts (such as th e S outh P ortico) is believed to have occu rred w ithin th e last forty-five years. S tone w eathering and d iscolouration are costly to repair: cleaning an d ren o v atio n o f th e C a th e d ra l’s N orth -W est T o w er du rin g th e early 1980s cost in the region o f £300,000 (F rien d s o f th e E a rth 1985). E lsew here in L o n d o n , W estm in ster A bbey has also suffered extensive dam age from air pollution. R esto ratio n o f ex tern al sto n ew o rk began in 1973, and th e plan is to reface alm ost all o f th e A bbey surface with P o rtlan d sto n e, at a cost in excess o f £10 m illion. C om pletion is not expected before th e early 1990s (T h e Tim es, 20 S ep tem b er 1985). St P au l’s and W estm in ster are not th e only B ritish cath ed rals facing

Effects on buildings and humans serious problem s from air pollution. The U K H ouse o f C om m ons Select Com m ittee (see chapter 10) noted th at many o f B ritain’s finest grand buildings are being affected (H ouse of Com m ons E nvironm ent C om m ittee 1984) - including Lincoln C athedral, Y ork M inster, Beverley M inster, B rom pton O rato ry , Liverpool C athedral, and the Palace o f W estm inster. Friends of the E arth (1985) point out that sulphur from central heating boilers may be im portant in city centres, but pow er station emissions are most likely sources at rural sites (e.g. Lincoln C athedral). Salisbury C athedral, painted by C onstable and visited by millions, is also on the casualty list. Its fam ous spire - which has stood tall for six and a half centuries - is now endangered by crum bling stonew ork and corrosion dam age and in 1985 an appeal was launched to raise the estim ated £6.5 million cost of restoring the spire and its supporting tow er (Spence 1985).

Cultural treasures Stained glass windows are also badly affected by air pollution. A w orld-fam ous specialist in the conservation and restoration of glass concluded in late 1985 that ‘if stained glass windows are kept in situ in their present state of preservation, th eir total ruin can be predicted within o u r generation’ (Frenzel 1985: 100) simply because of the corrosive effects of air pollution. H e gives the exam ple of W est G erm any’s massive, tw in-spired, high G othic C ologne C athedral (built around A D 1200), which was heavily adorned with grand stained glass windows. C ontinuous etching by air pollution has corroded the exterior surface o f the glass, reducing its thickness year by year, and giving the decom posed surface a ‘w eathering crust’. R ain w ashes over the crust and begins the cycle of destruction again. M eanw hile the coloured glass itself breaks into tiny particles, which fall out of the panel. This relentless attack by air pollution is not confined to Cologne - many o f E u ro p e’s finest cathedrals (including C anterbury in England and C hartres in France) are suffering in a similar way. O ver 100,000 stained glass objects in E urope are believed to be th reaten ed , with glass from betw een the eighth and seventeenth centuries at greatest risk (The T im es, 29 Septem ber 1984). D am age to the cultural heritage from air pollution is not confined to m ajor structures. N either is it confined to objects exposed o ut o f doors. The air inside art galleries, m useum s, libraries, churches, and o ther buildings also contains air pollutants (derived from outside), and the treasures housed within them - paintings, draw ings, fabrics, antique costum es, and so on - have suffered accordingly. W hilst many o f the w orld’s most im portant repositories are now air-conditioned to aid preservation, it is known that dry particles of sulphur dioxide can infiltrate simple ventilation systems and thus threaten contents (H oyle 1982). Fabrics soil, fade, and lose th eir tensile strength (i.e. rip m ore easily) in the presence of air pollution; regular cleaning and renovation are required (at a cost). V aluable oil paintings in non-air-conditioned m useums have

122 Acid Rain been found to be d am aged by air p o llu tan ts, requiring careful (and costly) resto ratio n and conservation w ork (S tern et al. 1973). L ea th e r becom es b rittle w hen exposed to su lp h u r p ro d u cts, and as far back as 1843 F araday concluded that th e ro ttin g o f leath er 'u p h o lstery on chairs in a L ondon g en tlem an ’s club was being caused by su lp h u r com p o u n d s in th e a ir (S tern et at. 1973). L eath er bindings on old books are also affected, and rep eated o pening o f th e em b rittled spines can cause co nsiderable dam age. O ld papers and bo o k s are also th re a te n ed because p a p e r ab so rb s S 0 2 and converts it to sulphuric acid (H 2S 0 4), which is dam aging. D am age is confined m ainly to p a p e r m ade a fte r 1750, and p articularly to m odern p ap er m ade by chem ical processes (m etals in th e processed p ap e r speed up the conversion o f S 0 2 to sulphuric acid; o ld er p a p e r was m ade from natural m aterials and lacks chem ical im purities) - the p a p er becom es very brittle and loses its fold resistance (C arr 1965). T hus old books th a t a re not sto red in sealed cases u ndergo gradual d e terio ratio n .

Cost of damage T his review has had to be selective, b u t it does illustrate th e m any ways in which acid deposition (norm ally in th e dry form ) affects m aterials. A s noted earlier, this dim ension of th e acid rain d e b ate has a ttra c ted less atten tio n than possible effects on forests and lakes, but it is serious and it does cost m oney. T h e fo rm er G re a te r L ondon C ouncil concluded in 1985 that ‘d eterio ratio n o f m aterials and buildings is probably the m ost costly (in econom ic term s) aspect o f air p ollution d am a g e ’ (p. 17). It is sh ared widely and difficult to distinguish from norm al ro u tin e building rep air and m aintenance costs. D am age to m aterials is am ongst th e m ost easily qu an tifiab le effects o f acid deposition - decreased lifetim e, rep lacem en t valu e, o r resto ratio n costs can often be calculated o r estim ated with reaso n ab le certain ty (W helpdale 1983). V arious estim ates have been offered o f th e cost of dam age to buildings and m aterials from air pollution (S tern et al. 1973) e.g. total costs in th e U SA (late 1960s) $104 billion p e r ann u m ; total costs in G re a t B ritain (early 1950s) $1.4 billion p e r an n um ; total costs in France (early 1960s) $0.6 billion p e r annum . M uch o f th e cost o f dam age to m aterials arises from co rro sio n and ero sio n . A 1981 E co n o m ic C om m ission for E u ro p e study (T o lb a 1983; 118) found th at corrosion o f p ain ted and galvanized steel stru ctu res costs $2-10 p e r y ear for each person living in E u ro p e . T h ese figures are o f a com parable o rd e r o f m agnitude to e arlie r estim ates - e.g. o f m aterial corrosion in th e U n ite d S tates (1970) at $7.10 p er p erson p er y e a r, in Sw eden (1970) at $4.30 p er person p e r y ear (K ucera 1976). Som e p io n eer atte m p ts to estim ate costs w ere m ade in th e B eav er C om m ittee R ep o rt in 1954 (see ch a p te r 1). It was estim ated th a t total econom ic loss from air pollution in E ngland was aro u n d £250 m illion p e r year (at m id-1950s’ p rices), com prising £150 m illion d irect costs an d a

Effects on buildings and humans further £100 million indirect costs (related to loss o f efficiency - e.g. in operation of transportation facilities). T he £150 million direct costs break dow n, roughly, as follows: laundry (£25m .), painting and decorating (£30m .), cleaning and depreciation o f buildings o th e r than houses (£20m .), corrosion of metals (£25m.), damage to textiles and other goods (c. £50m.). It has recently been estim ated (G reater London Council 1985) that air pollution produces dam age to buildings, m aterials, and structures across the U nited K ingdom as a whole in the range £16-£770 million per year (£0.28-13.75 per person p er year across the U K ); and dam age to buildings, etc. in London o f £2-100 million per year (i.e. £0.30-14.90 per person per year in L ondon). It is difficult to give precise estim ates of the tru e cost of building dam age, especially given the problem s o f defining the value o f historic buildings and treasures. It is clear that ‘no am ount of research can produce a costing for heritage loss caused by the dam age to historic m onum ents and statuary . . . when such national and international treasures are dam aged beyond redem ption, the w orld loses a priceless asset, for all tim e’ (D unm ore 1986:116). A ccepting this difficulty, most estim ates are based simply on repair costs. T hus, for exam ple, acid rain is believed to cause around $10 million dam age each year to historic m onum ents in the N etherlands; dam age to Cologne C athedral in W est G erm any costs $2 million a year simply to restore (H oyle 1982). It would be unwise to place too much em phasis on estim ates o f economic costs, because o f the difficulties o f arriving at realistic and m eaningful estim ates. B ut how ever the figures are arrived at, we are talking about vast sums of money! N one the less, this is only one com ponent o f the general problem , and we must turn now to possible effects of acid deposition on hum an health.

EFFECTS ON HUMAN HEALTH An evaluation of the problem s caused by acid deposition would be incom plete w ithout giving som e consideration to possible effects on hum an health. This them e has not attracted anything like such wide public interest as dam age to forests and lakes, but this is understandable given that (unlike many form s o f pollution) acid rain cannot be felt, sm elt, tasted, or seen. Acid rain itself is a truly invisible form o f pollution. M oreover, acid rain is not known to be m utagenic (i.e. gene changing) o r carcinogenic (i.e. cancer form ing) in hum ans. No one is known to have died directly from acid rain, and there are - as yet - few clear direct links with hum an diseases and disorders. D espite this lack of strong public interest, the issue is not w ithout significance. T here is a spectrum of effects o f acid deposition on hum ans, ranging from m ere nuisance (such as bad sm ells, reduced visibility, irritation of the eyes, nose, and th ro at) through to increased m ortality (C row e 1968). T here is now firm evidence that air pollution and hum an

124 Acid Rain health are closely associated in space and tim e. F or exam ple, the region of Katowice in southern Poland (source area o f the pollution th a t falls on Cracow and dam ages buildings there) suffers 47 p er cent m ore respiratory disease, 30 p er cent m ore tum ours, and 15 per cent m ore circulatory disease than the rest o f Poland (M ay 1982: 10). F u rth erm o re, ‘although there are no official figures collated as yet [1984], there are signs that babies have actually died in certain areas of W est G erm any from a th ro at infection, and the incidence of death is highest w here th ere is a greater direct pollution p roblem ’ (T he Times, 25 Septem ber 1984, p. 4). D eath rates from bronchial problem s in London have been much higher in the past during short episodes o f severe air pollution (see pages 126-7). It is perhaps convenient to distinguish two ways in which air pollution might affect hum an health - directly and indirectly. D irect effects involve dam age to the hum an body from exposure to pollutants, and in this sense m ost dam age is caused by sulphur dioxide in the dry gaseous and aerosol form . Acid rain per se (i.e. wet deposition) has no know n direct effects on hum an health. Indirect effects involve dam age to hum ans by contact with m aterials that have them selves been affected by acidification (by wet o r dry deposition) - obvious exam ples are food and w ater supplies.

Direct effects As noted above, direct effects arise largely from the fact that S 0 2 is a highly poisonous gas. It is described as a "non-specific irritan t’, which rem ains outside the body’s biochem istry; the body reacts to its presence (as opposed to ‘systemic poisons’ like lead, which affect specific body processes) (Lynn 1976: 83). In all higher anim als (including hum ans), S 0 2 is taken in by inhalation and attacks the respiratory system (m ainly the throat and lungs). In hum ans it is associated with chronic bronchitis, pulm onary em physem a (constriction of the lungs, which m akes breathing difficult), and - it is believed - cancer of the lungs. D ose-response relationships T he greater the concentration o f S 0 2 in the air b reathed, the greater the effects on hum an health. But the toxicity of S 0 2 varies with concentration, and it is difficult to establish a ‘safe level’. L aboratory studies have established that the dose-response relationships for S 0 2, N O x, and sulphate particles are not linear (i.e. a doubling of concentration produces m ore than a doubling o f the dam age), and that there are threshold values below which effects appear to be minim al. The effects of low co ncentra­ tions (i.e. low doses) are generally small and always difficult to detect. M ost dam age to hum an health is caused by S 0 2 in gas and aerosol forms. C oncentrations below about 0.6 ppm (parts o f S 0 2 per million parts o f air) norm ally produce no detectable responses in healthy hum an beings (A ir C onservation Commission 1965). It is known that a concentration o f 1.6

Effects on buildings and humans ppm will cause a tem p o rary (an d reversible) tightening o f th e bronchi (D uffus 1980) - th e tiny passages in th e lung via which oxygen (and contam inants like S 0 2) are ab so rb ed into th e blo o d stream . A bove 1.6 ppm , breath in g becom es detectab ly m ore difficult and eye irritatio n increases (because th e S 0 2 readily dissolves in th e fluids th at coat the hum an eye). B ackground levels com m only found in th e air o f industrial areas and m ajo r cities are in th e o rd e r o f 1 ppm (b u t levels can be much higher for short p eriod s). But those who w ork in th e chem ical industry often face occupational exposure to S 0 2 co n cen tratio n s in th e range 1-5 ppm (A ir C onserv atio n C om m ission 1965). M ost p eople can detect 5 ppm (exposure for o n e h o u r causes choking), and they find 10 ppm u npleasant (exposure for o n e h o u r causes severe stress from b reathlessness and tightness o f the chest). S ulphur dioxide increases the risk o f respiratory infection am ongst those w ho already suffer from resp irato ry deficiencies (e.g. asthm a sufferers). P rolonged exposure to high levels o f S 0 2 can cause d eath in hum ans, from resp irato ry p roblem s o r h eart failure (w hen b reath in g and any form o f physical activity becom e so difficult th a t they put excess strain on the h eart). N itrogen oxides are m uch less active biologically, so they cause few er p roblem s fo r hum an health and m uch higher co n cen tratio n s can norm ally be to lerated . Studies o f o ccupational exposure show th a t m ost p eople exhibit only w eak signs o f lung d isorders (pulm onary fibrosis and em physem a) at con cen tratio n s in th e range 10-40 ppm (L ynn 1976: 83). H igh co n centrations o f n itrogen dioxide (w hich in teracts w ith som e hydrocarbons and sunlight to p ro d u ce com plex chem ical irritan ts) are also know n to cause eye irritatio n . N orm al atm ospheric levels in cities and industrial areas rarely exceed 0.5 p p m , so h ealth is rarely affected. It is difficult to draw g en eralizations a b o u t how people respond to a given level o f S 0 2 o r N O x because som e individuals can to le ra te much higher levels than o th ers. Susceptibility varies considerably betw een individuals; those m ost at risk are th e aged, those w ho suffer from h eart diseases, those with im paired lung capacity, and those w ho are h y p er­ sensitive (p erh ap s because o f e a rlie r disease). G eneralizations are also difficult to arrive at because health is most badly affected by synergistic reactions (i.e. com plex chem ical interactions that bring w orse problem s than th e individual chem icals bring on th eir ow n). S 0 2 is m uch m ore toxic and dam aging w hen com bined with aerosols, acid m ists, and suspended sm oke (L ynn 1976: 83), because these chem ical cocktails form finer suspensions th at p e n e tra te th e lungs fu rth e r than the gas alone. M o reo v er, in sm oky conditions we ten d to b reath e m ore heavily, and so - paradoxically - ensure g re a ter p e n e tra tio n of the lungs by the pollutants. M ost o f the non-term in al effects cause short-lived suffering to th e p eople w ho are exposed to th e tem porarily high atm ospheric levels o f S 0 2 (e.g. associated with a bad episode o f pollu tio n). B ut because th e p roblem s are rarely so acute th at hospitalization o r visits to docto rs are req u ired , it is

126 Acid Rain difficult to establish ju st how w idespread o r serious th ey are. O n e indicator is the n u m b er o f com plaints lodged with the au th o rities; for exam p le, o ver 32,000 com plaints w ere received a b o u t high su lp h u r levels aro u n d T okyo in July 1974, and on num ero u s occasions since th en p eople cycling o r w orking o u t o f d o o rs in T ok y o have com plained o f suffering from eye and skin irritations believed to be caused by p olluted drizzle d ro p lets (O k ita 1983: 101). D isastrous pollution episodes It is perh ap s u n d erstan d ab le th a t th e best evidence is available fo r m ajo r disasters involving large-scale d e a th , w here the association betw een air pollution and d e ath is stro n g er th an circum stantial. T h re e such events involving sm ogs are well d o cu m en ted (M eeth am 1964; P erkins 1974). T h e first began on 1 D ecem b er 1930 in th e M euse V alley n ear Liege in B elgium (F irk et 1936). T his is a heavy industrial a re a , w ith m any industrial p oint sources o f p ollution (especially S 0 2), including iron and steel w orks, zinc w orks, glass w orks, p o tteries, lime kilns, electricity-generating statio n s, and sulphuric acid plants. A th erm al inversion (cold air overlying w arm ) trap p ed p o llu tan ts in th e low-lying valley, and th e lack o f n atural ventilation in th e stagnant air m ean t th at p o llu tan t co n cen tratio n s rose o v er the five days o f thick fog. The factories p rod uced a cocktail of po llu tan ts (including S 0 2, sulphuric acid, and zinc alum inium su lp h ate), which caused severe resp irato ry p ro b lem s for several h u n d red p eo p le in th e area. B ut the cocktail was a deadly one: sixty-three p eo p le d ied , m ainly on 4 and 5 D ecem b er and mainly by heart failure a fte r prolo n g ed perio d s o f acute irritatio n o f th e resp irato ry system and vom iting. S 0 2 c o n c e n tra ­ tions w ere later estim ated to be in the range 9 -3 8 p p m , which - if tru e - is exceedingly high. Sim ilar w eath er conditions gave rise to the disaster th a t befell th e tow n o f D o n o ra, south o f P ittsb u rg h , U S A , in late O c to b e r 1948 (S chrenk et al. 1949). A fog closed o ver the tow n on th e 26th, w ith air tra p p e d close to th e ground by therm al inversion. W hen it lifted five days la te r, it left a d eath toll o f tw enty (all w ere o ver 50 years old . m ost died on the th ird day). N early half o f th e to w n ’s p o p u latio n (o f 14,100) had been m ade ill, and a ten th had been severely affected; sym ptom s included irritatio n o f th e eyes, nose, and th ro a t, coughing, resp irato ry irrita tio n , h ead ach e, an d vom iting. T h e cause o f the disaster was su lp h u r pollution from th e to w n ’s steel mill, zinc production p lan t, and sulphuric acid p lan t. A gain, no m easu rem en ts o f S 0 2 levels w ere m ade at th e tim e o f th e d isaster, but la te r estim ates put the concentratio n at 0 .5 -2 ppm . T hese tw o events w ere insignificant in com parison with th e ‘killer sm og’ th at hung ov er L o n d o n , E n g lan d , betw een 5 an d 9 D e cem b er 1952 (W ilkins 1954; W ise 1971). It sta rte d , again by inversion, on th e T hursday. A w hite fog form ed , which was soon to becom e black, m ainly from sm oke (coal was used heavily in heatin g houses and in local pow er statio n s). T his

Effects on buildings and humans was yet a n o th e r ‘p ea-so u p er’ for which L o n d o n had becom e n o to rio u s (see ch ap ter 1). T he fog becam e th ick er and p o llu tan ts built up in th e stagnant air. V isibility soon fell to alm ost zero. O n e L o n d o n e r gave a vivid description: ‘you co u ld n ’t see o n e ’s h an d in fro n t o f o n e ’s face - a w hite shirt collar becam e alm ost black w ithin 20 m in u tes - sm og was intensely irritating to eyes, th ro at an d bronchi. A cough soon develo p ed . T h e cough was to rem ain with m e for m o n th s’ (P erkins 1974: 325). H e was lucky . . . the sm og took an estim ated 4,000 lives, mainly from b reath in g problem s. T he d eath s w ere spread o v er a p erio d of w eeks, b u t m ost o ccurred betw een th e 4th and 10th. T hey w ere confined m ainly to th e ill and the elderly. T he excessive d e a th toll in this d isaster is believed to reflect the synergistic effects o f high levels o f S 0 2 co upled with high levels o f sm oke (particulates). T he m axim um daily S 0 2 co n cen tratio n was m easured at the tim e as 1.34 ppm ; the highest sm oke level was 4.46 j.ig. m 3 (P erkins 1974). T hese are average values and m uch higher co n cen tratio n s w ere doubtless experienced for sh o rt p erio d s an d in som e areas. T h e significance o f this synergistic effect is illustrated in th e fact th at a subsequent ‘killer sm og’ fell o v er L ondon from 3 to 7 D ecem b er 1962 (Scott 1963). Levels o f S 0 2 w ere sim ilar to those o f th e 1952 ev en t, but th e 1956 C lean A ir A ct (see c h a p te r 1) had by now b rought a m arked d ro p in sm oke levels over L on d o n . T h e d eath toll in 1962 was accordingly low er. 340 died in the L ondon A dm in istrativ e C o u n ty as o p p o sed to 2,000 in 1952. B etter aw areness o f th e possible health hazard o f p rolonged sm og, in the w ake o f th e 1952 event (which received w idespread publicity), is also believed to have been a factor in keeping d e ath s dow n in 1962. M any p eople with chest com plaints had th e sense not to go o u t o f d o o rs and expose them selves to risk. T hese th ree disasters highlight the very serious effects o f high levels o f atm ospheric S 0 2 on hum an h ealth . F o r every person th a t d ied , th e re w ere countless o th ers w ho survived b u t suffered in various ways and to varying extents from irritation o f th e eyes, nose, and th ro a t, coughing, difficulty in b reath in g , h eadaches, and vom iting. A p art from th e toll on hum an life and the drain on hum an w elfare, such p o llution incidents have potentially massive econom ic im plications - th e costs o f hospitalization and m edical care, loss o f productivity through absence from w ork, o r inability to w ork at full stren g th , and so on. B ackground levels a n d epidem iological studies T h ere are dangers in focusing o n ly on disasters such as th e th re e outlin ed above, because - by definition - they rep resen t highly in freq u en t and u n rep resen tativ e ex trem e conditions. It is as relev an t h ere to co n sid er the effects o f m ore ‘n o rm a l’ (th at is, back g ro u n d , o r am b ien t) levels o f pollution on hum an h e alth , which a re generally ev alu ated in ep id em io lo ­ gical studies (epidem iology is ‘th e study o f th e factors involved in the distribution an d frequency o f a disease process in a given p o p u la tio n ’ -

128 Acid Rain Perkins 1974: 325). We must not overlook the great difficulty o f estab ­ lishing how individual pollutants affect hum an health because o f the large num ber of factors and variables involved (D urzel and C etrulo 1981; Kim 1985; Lipfert 1985). T he medical literature on the epidem iology of S 0 2 is wide and reviewed elsew here (Perkins 1974), but some generalizations can be drawn from it. M ost levels of S 0 2 to which hum ans are comm only exposed are not fatal, except to unusually sensitive individuals. But it is a m ajor cause o f illness, disability, and discom fort. Sulphur dioxide appears to affect the low er respiratory tract (i.e. lungs), particularly in term s of infections, m ore than the u p p er tract (i.e. nose, th ro at, and w indpipe), which explains why it affects breathing. It also explains why S 0 2 prom otes and aggravates disorders such as bronchitis and em physem a. T he effects on breathing may produce m ore than discom fort; they bring reduced efficiency in undertaking any form of physical activity (including walking, lifting, gardening, etc.). A thletes have been found to perform much worse in polluted air than in clean air, but it is not clear w hether this is a direct causal effect o r stem s from discom fort (e.g. from eye irritation). T here w ere, for exam ple, w orries abo u t the possible effects on the health of athletes taking part in the 1984 Olympic G am es in Los A ngeles, a city with a long history of sm og problem s (Elsom 1984), but these proved to be w ithout foundation. T he im pact o f air pollution on body reactions is also illustrated in studies th at have established a statistically significant association betw een oxidant levels and rates o f m otor vehicle accidents in Los A ngeles (Perkins 1974), though again the link may not be direct and causal. Epidem iological studies also show th at it is not just short-term exposure to high concentrations o f S 0 2 that causes health problem s. L ong-term (at least several years) exposure to low levels of S 0 2 pollution (below 0.05 ppm ) can produce detectable health dam age to children and adults. T hey also show that nitrogen oxides affect health. L aboratory tests have shown that N 0 2 (nitrogen dioxide) increases the susceptibility of anim als to bacterial infections, and such effects may also occur in hum ans. For exam ple, a study in C h attanooga, U S A , found th a t high levels o f N 0 2 reduced the breathing efficiency of children and significantly increased incidence rates of illnesses am ongst parents and children (Shy et al. 1970). A study of the north-east o f England found that death rates from lung cancer and bronchitis are up to twice as high in heavily polluted urban areas as in the surrounding countryside, even taking into account sm oking habits. It concluded: ‘the im plication that air pollution might play an im portant role in relation to h ealth ’ . . . (especially lung cancer) . . . ‘is too strong to ignore’ (T he Times, 25 A pril 1978). Studies like these indicate that long-term exposure to am bient levels o f air pollution by S 0 2 and N 0 2 can have serious and detectable adverse direct effects on hum an health. The disaster studies and the epidem iologi­ cal studies, viewed alongside circum stantial evidence, indicate th at high

Effects on buildings and humans co ncentrations o f S 0 2 and N O x (and d oubtless o th e r p o llu tan ts like ozone - C olbeck 1985) - i.e. dry d eposition o f acids - can cause d irect h arm to hum ans (m ost notably bronchial an d lung com plaints) via inhalation. C on cen tratio n s o f S 0 2 and N O x high enough to cause serious health problem s are norm ally fo und only close to em ission sources - i.e . in m ajo r cities and industrial areas - a n d , even th e n , often only u n d e r unusual w eath er conditions (e.g. th erm al inversion) a n d /o r w hen em issions are unusually high (e.g. durin g w in ter, w hen large q u an tities o f fossil fuels are being b u rn ed for heatin g and pow er g en eratio n ). T he evidence suggests th at S 0 2 and N O x levels in m any m ajo r cities (such as L ondon and N ew Y o rk ) have been declining o ver the last decade as a result o f air pollution co n tro l legislation. T h e im plication is th at disasters like those at D o n o ra and L ondon should not h ap p en again, at least on such large scales, and th a t m ore general health dam age from exposure to am bient levels m ight also be expected to d ecrease in th e future.

Indirect health effects T h ere is as yet little evidence to link wet acid d eposition with d irect effects on hum an health. B ut this does not m ean th at w et depo sitio n has no effect, or th a t its effects are insignificant. T h ere are at least tw o im p o rtan t indirect routes by which acid rain m ight affect hum an h ealth , and b o th involve toxic heavy m etals. H eavy m etals (such as co p p e r, zinc, cadm ium , an d m ercury) are liberated w hen soils and deposits are acidified (see ch a p te r 5). T hese m obilized contam inants are dissolved in soil w ater, so th ey can readily infiltrate g ro u n d w ater o r seep o u t o r flow into rivers an d lakes. T hey can also be taken in - along with m oisture and n u trien ts - by plants (via root osm osis) and by the grazing anim als th a t eat those plants. T hus g roundw ater th at is d ru n k by h um ans and food (fish, m eat, and vegetables) th at is eate n by hum ans can be co n tam in ated with toxins, which are taken into the body by digestion (T h o rn to n and W ebb 1979; T h o rn to n and Plant 1980). T he hum an body stores ra th e r than releases this heavy m etal m aterial, and so high (and p o tentially very dam aging) co n cen tratio n s can build up by the accum ulation o f small doses o v er long tim e-periods. C adm ium and the o th e r heavy m etals are c o n cen trated in plan ts, th en anim al bodies, and eventually in hum ans as they m ove up the food chain; those at the to p o f th e ‘p ile’ intake th e largest (and m ost toxic) concentrations. T h ere are rep o rts o f edible fish being co n tam in ated by toxic m etals (m ainly m ercury) (T olba 1983). T his can result in m ercury poisoning in hum ans; the Jap an ese have experience o f this in th e form o f M inam ata disease. F arm ing crops can also be co n tam in ated by heavy m etals (especially cadm ium ) th rough m obilization in acidified soils. D rinking w ater supplies can be affected by increased levels o f toxic

130 Acid Rain heavy m etals (particularly alum inium , m an g an ese, co p p e r, cadm ium ) in tw o ways (M cD onald 1985) - from leaching from soils in catc h m en ts, and from corrosion o f w ater storage an d distrib u tio n system s (m ost notably from galvanized steel and co p p er w ater pipes). T h e re is evidence o f co n tam in ated g ro u n d w ater in so u th ern Sw eden, p a rts o f O n tario in C an ad a, and in th e A d iro n d ack region in N ew Y ork state (T olba 1983; A non 1984/5e). N o rep o rts have yet a p p e ared o f seriously co n tam in ated w ater supplies in B ritain. R esearch is still in progress into th e possible h ealth conseq u en ces o f drinking w ater with high levels o f heavy m etals, b u t th e re is evidence th a t it is associated with increased incidence o f osteo m alacia, an uncom m on b o n e disease which in th e past was linked with vitam in D deficiency and rickets (T he T im es, 14 S ep tem b er 1985). R esearch in th e U n ited S tates an d G reat B ritain show s th at m any m ore cases o f th e disease are observ ed in areas w ith high co ncen tratio n s o f alum inium in w ater supplies (such as M anchester and N ew castle in E n g lan d ) th an elsew here. C o n tam in ated g ro u n d w ater has also been linked with h ealth p roblem s in babies. In som e rural p arts o f west Sw eden, babies have been suffering from d ia rrh o ea on and off fo r m onths an d this has only occu rred in areas w here d rinking w ater com es from acidified wells an d has an abnorm ally high co p p er co n ten t (L a Bastille 1981:675-6). D rin k in g w ater supplies in industrial cou n tries are cleansed by p ro p er tre a tm e n t techniques. P roblem s a re m ore serious w here w ater supplies are ta k e n from w ells, springs, local p o n d s, o r lakes (B allance and O lson 1980). F o r exam ple, in Sw eden o v er I million p eople rely on w ater draw n from th e ir ow n w ells, and ab o u t h alf o f them live in areas w here acidified lakes are com m on (Sw edish M inistry of A griculture 1984). H igh co n cen tratio n s o f heavy m etals have been reco rd ed in acid well w aters in Sw eden. T h e acidification o f g ro u n d w ater brings o th e r p ro b lem s, to o . A m ongst th e m ost colourful is the effect o f p eople in so u th ern Sw eden w ashing th eir blond h air in w ater from co p p er p ipes th a t have b een c o rro d ed by acidification - th e c o p p er sulphate from th e plum bing discolours th e ta p w a te r, but it also tu rn s th e h air bright g reen (L a Bastille 1981: 659)! T he only o p tions fo r affected fam ilies are to replace th e co p p er plum bing and install filters, dig d e e p e r w ells, o r learn to like green h air.

CONCLUSION It is clear th at acid d eposition can cause serious dam age to buildings and m aterials, and it can bring serious h ealth problem s fo r hum ans. B o th wet and dry deposition create p ro b lem s, in b o th d irect an d in direct ways. M ost o f th e dam age to buildings and h u m an s arises in urban an d in dustrial cen tres (ra th e r th an across the countryside at larg e), reflecting the dom inance of local sources o f em ission o f S 0 2 and NO* an d th e d o m inance o f short-range dry d eposition. T he costs o f dam age to buildings and

Effects on buildings and humans hum ans are far from insignificant, and the inconvenience and hardship so created are far from acceptable. O ver two decades ago the following conclusion was drawn about the problem s of air pollution from sm oke: In towns and industrial districts rain w ater loses its purity; ash and o ther solids fall continuously to the ground; the air contains a suspension of fine particles which p en etrate indoors, to be deposited on walls, ceilings, curtains and furniture; o u r clothing, our skins and o u r lungs are contam inated; m etals corrode, buildings decay, and textiles w ear out; vegetation is stunted and blackened; sunlight is lost, germ s multiply; our natural resistance to disease is low ered. In a hundred and one ways the miasm a of atm ospheric pollution is lowering o u r vitality and our enjoym ent o f life. (M eetham 1964: 4) Since the mid-1950s in G reat Britain and the late 1960s in the U nited States legislation has attem pted to reduce this com ponent of air pollution, and it has been successful in doing so. H ow ever, the legislation has not been entirely successful in reducing air pollution, and a similar conclusion can be draw n today about the problem s of pollution from acid gases, mists, and aerosols.

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Part III THE TECHNOLOGY OF ACID RAIN

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7 CURES AND REMEDIES ‘We have the technology..

Progress, th e re fo re , is not an accident, hut a necessity . . . It is a p art of n ature. (H e rb e rt S pencer, Social Statics, 1850, pt i, ch. 2: 4) W e have seen in P art II th a t considerable scientific u ncertainty still surrou nds m any aspects o f the effects o f acid rain , d espite m uch research in m any areas. Som e critical q u estio n s rem ain as yet largely un an sw ered , such as the linearity o f th e relation betw een oxide em issions and acid d eposition, and o f that betw een levels o f d eposition and observed dam age. A s a result th ere is still n o universally accep ted consensus on th e need for rem edial m easures, o r on w hat types o f m easure might be most a ppropriate. In this ch ap ter we shall exam ine th e m ain p roposed solutions to the p roblem s o f acidification in th e env iro n m en t. T hey fall into tw o groups cure and prevention. C urative m easures can be applied w here the problem s (e.g. acidification o f soils and surface w aters) actually arise. Preventive m easures can be applied at source (i.e. at p oints o f em ission of the sulphur and nitrogen oxides). T h e latter are m ore effective, m ore sustainable, and m ore urgently req u ired . T hey are also the m ore expensive (at least in the short term ) and th e least acceptable to (and frequently overlooked by) industry and to som e governm ents.

CURE BY BUFFERING It is com m on sense th a t pro b lem s can best be d ealt w ith by m aking sure that they never h appen in th e first place; but if they do (o r are allow ed to) h ap p en , then they m ust be solved quickly and econom ically (i.e. cost-effectively). Ideal solutions are also sustainable and cause m inim um interference. T h e only acceptable long-term ‘so lu tio n ’ to p roblem s o f acidification is p rev en tio n , but in th e short term th e re is a pressing need to cure the dam age it has already caused. T his req u ires not simply the rem oval o f sym ptom s o f dam age (e.g. restocking fish in acidified lakes and rivers, planting new tre es in a reas affected by forest dieb ack , o r cleaning discoloured building facades); it also req u ires resto ratio n o f n atural chem ical balances to en su re th a t dam age does n o t recur.

136 Acid Rain We have already en countered th e n atural ability o f som e m aterials to buffer, o r effectively neutralize, o r counteract acid inputs. Lim e and lim estone are the m ost popular o f a range o f chemicals (including caustic soda, sodium carb o n ate, and dolom ite - T olba 1983: 118) th at can be used to buffer acidic m aterials. Lim estone bedrock and lime-rich deposits offer a natural buffer capacity to soils and catchm ents (chapter 3); similar chemical reactions explain why lim estone and dolom ite building m aterials can be badly attacked by dry and w et acid deposition (chapter 6). This buffer capacity o f lim e-based m aterials has been eagerly seized upon as a basis for ‘curing’ (i.e. counteracting) som e o f the biological dam age caused by acidification. Lim e has been added - norm ally by aerial spraying from helicopters - to rivers, lakes, soils, and forests in a num ber of areas to reduce acidity, alleviate dam age, and im prove conditions for plants and anim als (A non 1984/5c; M cCorm ick 1985). The approach has been m ost widely explored in Sw eden, w here liming of acidified lakes began on an experim ental basis in autum n 1976. W ithin two years, some 200 lakes had been lim ed, and a further 700 were lim ed betw een 1977 and 1979 mostly with governm ent support (B engtsson, D ickson, and Nyberg 1980). By sum m er 1985 over 1,500 lakes had been limed (Swedish M inistry of A griculture 1984). Liming raises the pH of w ater, thus im proving conditions for plants and anim als. It fixes the dangerous alum inium ions (see chapter 4), which are then precipitated on to the lake bed, and it also reduces the freely available m ercury in the w ater - both to the advantage of fish and o th er aquatic species. Sw eden’s experience is one of escalating costs: the budget of $2.5 million for 1980 (B engtsson, D ickson, and N yberg 1980) had risen to $7.5 million by 1983 (M ay 1982:11), and it is expected to rise much further. This is clearly an expensive ‘cu re’, but it has produced encouraging results (e.g. recolonization by indigenous phytoplankton, zooplankton, and fish B engtsson, D ickson, and Nyberg 1980) and is regarded as the only practical alternative without o r pending w idespread adoption of emissionreducing technology. Liming has also been used as a m eans of restoring acidified soils, at least tem porarily. The calcium counteracts the harm ful effects of acidity and alum inium , and im proves the productivity of acidified croplands and forests. This form o f land m anagem ent is far from new . because lime has for centuries been added to acidic and calcium -poor soils as a m eans of im proving texture and chemical status (although the application o f nutrient fertilizers usually has the reverse effect of increasing soil acidity - Friends of the E arth 1985). W hat is new, and som ewhat unacceptable, is the need to use liming to counteract the disturbing influence o f acid deposition derived from air pollution. This spreads the true cost of air pollution am ongst farm ers (see, for exam ple, Figure 5.6) and foresters, rath er than being m et by those who produce the pollutants (the pow er stations and industrial point sources). It also speeds the long-term d eterioration of soil productivity, because lime

Cures and remedies cannot simply be ad d ed to a given soil in grow ing q u an tities, seem ingly for ever, w ithout adverse w holesale changes in soil status. A lso u n acceptable is any grow ing reliance on th e need to add lime to soils simply to m aintain farm ing productivity in areas th a t receive large inputs o f acids from air pollution. In B ritain, th e need fo r lim ing in m arginal upland farm ing a reas was for m any years form ally recognized by the provision o f g ran t su p p o rt from the M inistry o f A g ricu ltu re, b u t this grant su p p o rt was rem oved in 1976. Since th en m any farm ers have eith e r ceased lim ing, o r apply lime less freq u en tly ; total applications o f lim e on B ritish farm s fell from 4.6 m illion to n n es in 1976 to 3.2 million to n n es in 1984 (F riends o f the E a rth 1985). T h ere are fears th at this reduced buffering m ight speed soil acidification, reduce soil fertility, and possibly ultim ately lead to declining agricultural yields (hence increase B rita in ’s d ependence on food im ports). Lim ing does alleviate som e o f th e w orst sym ptom s o f acidification, b u t it is not a real o r sustainable cure because it does not attack th e ro o t causes o f the problem s (T olba 1983: 118; H jelm 1984). A s a m eans o f buying tim e it has wide p o ten tial, but th e re is no escaping its in h eren t draw backs. T h e benefits can be short lived, in th a t it w orks for a tim e th en the effects becom e neutralized by fu rth e r acid inputs (th e dosages ad d ed to Swedish lakes are designed to last for five years - B engtsson, D ickson, and N yberg 1980). M oreover, it is not p racticable o r suitable for m any lakes and rivers; som etim es lim ing is o f n o help at all. Lim ing also pro d u ces its ow n problem s, through th e d eposition o f th e toxic heavy m etals (e.g. alum inium ) previously m obilized in the lake w aters, which poison lake b o ttom dw elling organism s (Sw edish M inistry o f A gricu ltu re 1984). It is certainly a costly solutio n , and one th a t needs rep eatin g frequently. D espite the conclusion by B rita in ’s W att C o m m ittee (1984) th at the lim ing of exposed lakes m ay be th e m ost effective m eans o f control for acidified lakes, which m ay cost only ‘a few p ercen t o f m easures to retrofit pow er statio n s’, lim ing is an interim m easure th at provides a sh o rt-term biological defence. It is ‘a sort o f artificial resp iratio n for dead lakes and stream s’ (M ay 1982: 11), a m eans ‘o f keeping poorly bu ffered o r acidified w aters alive’ (B engtsson, D ickson, and N yberg 1980: 35) - until oxide em issions can be reduced to ad eq u ately low levels. T his can o nly h appen through a d elib erate and su stained policy o f p rev en tio n , ra th e r than cure.

PREVENTION T he focal point o f the political d eb ate o ver acid rain (see P art IV ) is the need to reduce rainfall acidity by controlling em issions o f S 0 2 and N O x at source; i.e. prevention. A cross the U nited K ingdom as a w hole ab o u t a q u a rte r o f the acidity is derived from N O x, th e o th e r th re e -q u a rte rs from S 0 2 (C larke 1985: 5). A b o u t tw o-thirds o f th e S O z and nearly half o f the N O x com es from th e b urning o f fossil fuels (m ainly coal and oil) in conventional pow er statio n s (F igure 7.1).

F ig u re 7.1

M ain sou rces o f emissions o f sulphur dioxide an d nitrogen oxides in the U n ite d K ing do m , 1980

United Kingdom

(1980)

R e fin e rie s and Industry

S U L P HUR D IO X ID E

N IT R O G E N O X ID E S

Power S ta tio n s

D om esti 5%

T r a n s p o rt Dom estic Commercial and Public

C om m ercial a nd P u b l i c 4 . 0 % ran sp o rt 2 .0 %

T ransport28%

D om estic 23%

C o m m e rc ia l and P u b lic 3 % Source:

based on data in Table 2.3, after Scriven (1985)

Cures and remedies It is u n d erstan d ab le, in the light o f this, th a t so m uch a tten tio n in th e d eb ate has cen tred on pow er statio n s as m ajo r villains in th e piece, and th at so m any and w ell-orchestrated calls have been m ade to en su re th at pow er stations cut th eir oxide em issions sharply and w ithout fu rth e r delay. It is th erefo re o f m ore th an passing in terest to consider w hat m eans exist to reduce em issions o f S 0 2 from p o w er statio n s, an d em issions o f N O x from pow er stations and vehicles.

Reducing emissions of S 02 from power stations All fossil fuels contain som e su lp h u r, and coal has a higher su lp h u r co n ten t than oil and gas. S ulph u r occurs naturally in coal in th ree form s - as iron pyrites (F eS 2, an inorganic su lp h id e), organic com pounds (b o u n d into organic m a tte r), an d sulphates. O nly th e first tw o are o f m ajo r im portance by q u antity o r im pact (P erkins 1974: 263). H ow ever, th e total sulphur co n ten t o f coal varies considerably from deposit to deposit: in com m ercial coal it norm ally ranges betw een 0.3 p e r cent and 5 p e r cen t (by w eight). A sulphur co n ten t above a b o u t 1 p e r cent - typical o f the N o rth A m erican coal m ined from the vast dep o sits east o f th e M ississippi (P riest 1973: 75) is regarded as 'h ig h '. A s described in ch ap te r 2, oxides are form ed w hen a fossil fuel is b u rn ed at high te m p eratu re in air. T h e am o u n t o f oxides pro d u ced d ep en d s in p art on the sulphur co n ten t o f th e fuel source (both increase to g eth e r) and in p art on the te m p eratu re o f com bustion (again, both increase to g eth er). W hen coal is b u rn ed , the m ain oxide pro d u ced is sulphur dioxide ( S 0 2), the key ingredient in th e acid rain d eb ate . T h ere is only one way o f elim inating S 0 2 em issions alto g eth er, and that is to stop burning fossil fuels fo r energy pro d u ctio n . G iven o u r heavy reliance on available energy to d ay , such a solution is n o t view ed as a practical op tio n . T he altern ativ e is to reduce S 0 2 em issions, and the serious search for viable m eth od s o f doing this has been on for o v er a decade (Ludw ig 1969:23). F o r exam ple, in 1973 ten d ifferent schem es w ere being tested on large ( > 100 M W ) pow er statio n s in the U n ited S tates alone, and a fu rth er tw enty w ere at th e p ro to ty p e stage (P erkins 1974). Som e control technologies have em erged as m ore econom ically viable, energy efficient, o r operatio n ally practical th an o th ers. W hat follow s is an attem pt to sum m arize in a non-technical m an n er th e m ain options presently available; technical trea tm e n ts are available elsew here (P erkins 1974; Lynn 1976; E lsw orth 1984a). O ption 1. B urn less fo ssil fu e l This is seen by m any scientists and all conservationists as the best and certainly the m ost p erm a n e n t solution to the problem o f reducing S 0 2 (and N O x) em issions at source. T h e goal is to p ro m o te long-term red u ctio n s in consum ption o f coal and oil in conventional po w er stations. T his can be achieved in tw o w ays, applied sep arately but preferab ly to g eth er.

140 Acid Rain (a) Energy conservation: R ed u ced fuel consum ption will follow from a successful and sustained energy conservation p ro g ram m e . A significant reduction in overall energy use in dev elo p ed co u n tries in th e fu tu re seem s highly unlikely, but th e re are som e p rospects o f stabilizing an d real prospects o f reducing th e rate o f grow th o f energy use. T his w ould req u ire m ore efficient use o f existing fuels, and technical im p ro v em en ts could ensure th at processes b u rn ed fuel m ore efficiently (T olba 1983: 118). It w ould also require im proved th erm al insulation o f buildings. It w ould certainly be b oth possible an d sensible to pass on to th e energy u ser som e degree o f responsibility fo r m ore careful use o f available energy resources. F o r th e industrial user this might include tax concessions o r o th e r financial inducem ents fo r installing energy-efficient technologies. F o r the individual d om estic energy u ser, th e choice ranges from th e sim ple act o f sw itching off lighting and heatin g w h erever possible, to th e m ore d em anding act o f adjusting purchasing strategies in favour o f energyefficient goods. M ost individual energy users could red u ce th eir energy consum ption w ithout facing u ndue personal h ardship o r inconvenience indeed they w ould reap th e benefit o f low er energy bills, as well as the satisfaction o f know ing th a t they have played a role (no m a tte r how sm all) in reducing acid rain! E lectricity (externally supplied) is w idely view ed by th e individual user in the sam e way th at they view w ater from th e tap (externally su p p lied ) freely available in ab u n d an ce to be used w h ere, w hen, and how you d ecide, and at w orst you pay fo r w hat you use! C on su m ers need to be m ade aw are o f th e folly o f this view , and this is best d o n e by 'aw aren ess building’ cam paigns (ra th e r th an th ro u g h cost levels designed to p ro m o te less profligate use). G o v ern m en t initiatives th a t ed ucate energy users - like B ritain ’s national ‘M O N E R G Y ’ cam paign o f 1986 - serve a key role in this respect. A ll such conservation schem es are long te rm , so th a t any co n tribu tio n they m ight m ake to overall red u ctio n s in oxide em issions will be extrem ely difficult to d etect and quantify. B ut th e p o st-1974 ‘energy crisis’ - reflected in wildly escalating energy costs and b ro u g h t a b o u t largely by O P E C oil price rises - has en co u rag ed m ore co n sid ered use o f energy and th e search fo r suitable altern ativ es to fossil fuels. (b ) Substitution o f fu e l sources: O xide em issions from po w er statio n s can also be reduced by sw itching at least a p o rtio n o f th e total energy p ro d u ctio n capacity to non-fossil fuel sources. S ubstitution is also seen as a long-term so lutio n , with su lp h u r em issions declining slowly o v er th e p erio d o f replacem ent. T h ere are a nu m b er o f sulphur-free su b stitu tes to choose from . E nergy can be derived from w ood, natural gas (m e th a n e ), p etro l (g asoline), paraffin (k ero se n e ), an d gas oil. E lectricity can also be g e n e ra te d from renew able energy sources such as th e su n , w inds, tid es, w aves, falling w ater (hydro-electricity), an d n atu ral heat in th e e a rth ’s crust (g eo th erm al

Cures and remedies energy). T h ere are m any research initiatives u n d er way in so-called 'low energ y ’ (o r ‘altern ativ e ’ o r ‘so ft’) technology, which are based on use of renew able sources o f energy (Saw yer 1986). B u t m ost such sources are lim ited by geographical factors and they req u ire vast energy storage capacity to m atch supply and d em an d in b oth tim e and space. E ach o f these sub stitu tes m ight offer som e scope for local use, particularly in isolated co m m unities, but th eir p o ten tial fo r supplying anything like the natio n al req u irem en ts o f energy in co untries like th e U nited K ingdom and th e U n ited S tates is very lim ited by geographical, practical, and econom ic factors. T h e only viable su b stitu te, given to d ay ’s scientific und erstan d in g , is nu clear pow er (L ynn 1976) which - even its stern est critics (like F rien d s o f th e E a rth 1985) co ncede - has vast potential. C onventional nuclear pow er statio n s g e n erate electricity from rad io ­ active uranium using th e fission process, w hich involves co nverting sm all am ounts o f u ran iu m ’s mass directly into energy (Lynn 1976). U ranium reserves w orld-w ide are som ew hat lim ited, how ever, and so recen t in terest has cen tred on the scope fo r using plutonium in th e fission process. T his requires ‘b re e d e r’ (or ‘fa st-b ree d e r’) reacto rs, which ‘b re e d ’ fuel by converting non-fissionable (i.e. unusable) types o r isotopes o f uranium into fissionable (i.e. usable) fuel. R esearch is u n d er way into th e next generation o f reacto rs, which will tap th e nu clear fusion process (in which tw o sm all atom s o f th e d eu teriu m isotope o f hydrogen are fused to g eth er into a larger helium ato m , w hich co n trasts with th e fission process in which large uranium atom s a re split into sm aller pieces), b u t large, com m ercially viable, an d operationally safe fusion pow er stations are - as y et - som e way into the future. N uclear pow er presently supplies less than 5 p e r cent o f th e energy used in the U n ited S tates (Saw yer 1986) and aro u n d 8 p e r cen t o f B rita in ’s energy (Fishlock and W ilkinson 1986), b u t b o th co u n tries have a com m itm ent to expand th e nu clear pow er base (and ongoing program m es to do so). In on e sense, expansion o f nu clear pow er w ould m ake a useful contribution to reducing acid rain , because nu clear plants release no gas pollutants containing su lp h u r o r n itrate com pounds. B ut to argue in favour of a nuclear program m e sim ply from this perspective w ould be com pletely to overlook the im m ense p ro b lem s o f co nverting and storing the radioactive w aste pro d u cts so unavoidably p ro d u ced in n u clear pow er stations. It w ould also be to o verlook the very real dangers o f n uclear reactors, an d the health h azards they pose to hum ans - w hich are both direct (contam ination with radioactive fallout) and indirect (via co n tam ­ inated food and w ater supplies). In th e w ake o f th e C hernobyl (U S S R ) disaster o f M arch 1986 (Serrill 1986), and th e ‘near-m iss’ at T h re e Mile Island, H arrisburg (U S A ) in M arch 1979 (B u n y ard 1979), such an oversight w ould be h a rd to defend! W e m ust conclude th a t th e o p tio n o f large-scale substitution o f fuel sources is not w ithout its in h eren t lim itations an d a tte n d a n t d an g ers, and

142 Acid Rain concede th at O p tio n 1 m ight m ake a co n trib u tio n to th e oxide em ission p ro b lem , but not the largest one. O ption 2. Switch to low -sulphur fu e l W e n oted above th e n atu ral variability in su lp h u r c o n te n t o f fossil fuels. G iven o u r heavy reliance on conventional m eans o f producing energy w hich in practice m eans burning coal, oil, and gas - it is logical to seek to m inim ize oxide em issions at source by bu rn in g fuel with th e low est possible su lphur co n ten t. T his o p tio n offers o n e o f th e easiest ways o f controlling S 0 2 em issions from pow er statio n s, which does not req u ire costly investm ent in pollu tio n -co n tro l technology (and high recu rre n t running costs). In th e U n ited S tates during the late 1960s, th ere was m ou n tin g public pressure on n atio n al, sta te , and local gov ern m en ts to curb air po llu tio n , and this w as th e only practical m eans o f lim iting S 0 2 em issions th en available. C onsequently regulations lim iting th e su lp h u r c o n ten t o f fuels for use in com bustion installations (p o w er p la n t, industrial b u rn ers, e tc.) w ere passed in a n u m b er o f cities and states (L ynn 1976). T his ap p ro ach was ad o p ted in New Y ork City in 1965, w hen an u p p e r limit o f 1 p er cen t sulphur in fuel was im posed. A significant d ro p in S 0 2 levels o v er th e city, especially at low ( < 0.5 ppm ) c o n cen tratio n s, was n o ted o v er th e follow ing years (E isenbud 1970). W ashington D C also forced th e G en eral Services A dm in istratio n to switch to low er-sulphur fuels in th eir heatin g installa­ tions, and an im provem ent in air quality follow ed (L ynn 1976). A n interesting variant on the ‘low -sulphur fuel’ o p tio n has been tried in the U n ited States, w here som e large pow er stations have been designed w ith th e capacity to switch fuel sources as and w hen req u ired . F or exam ple, som e statio ns routinely switch fuel from season to season - partly to capitalize on variable fuel costs and partly to m inim ize su lp h u r em issions u n d er p articu lar w eath er conditions (L ynn 1976). Som e pow er statio n s in urban areas switch to low -sulphur fuel for short p erio d s (L ynn 1976), when adverse w eath er conditions w ould cause serious pollution episodes (see ch ap te r 6). T his option do es, th e re fo re , offer som e p rospect o f co n trib u tin g to a net reduction in S 0 2 em issions. B ut it does have its lim itations. A critical constraint is the lim ited availability o f low -sulphur coal in m ost co untries. In the U n ited K ingdom , for exam ple, only a sm all fraction (15 p er cen t) o f th e available coal has a su lp h u r co n ten t less than 1 p e r cent (T able 7.1). Potential supplies o f low -sulphur coal in th e U nited S tates are much higher, but m ost reserves are long distances from pow er statio n s so th at tran sp o rt costs a re very (som etim es prohibitively) high (P riest 1973:75). A n ad d ed co n strain t, closely related to relative sh o rtag e, is th e relatively high cost o f low -sulphur fuel. N orth A m erican experience during th e 1970s has show n how dem an d -led com petition - m any users sw itched from high-

Cures and remedies Table 7.1

Sulphur content o f United Kingdom coal, 1982-3

Source area

Average sulphur content (%)

Scottish South-west opencast South W ales Scottish opencast South Notts N orth Notts D oncaster N orth-east W estern South Midlands North-east opencast South Yorks N orth Derbyshire Barnsley N orth Yorks C entral east opencast Central west opencast North-west opencast

0.70

Total

Saleable output (million tonnes)

0.90 0.95 0.95 1.37 1.48 1.48 1.49 1.52 1.56 1.56 1.59 1.69 1.85 1.92 1.96 2.07 2.34

6.6 2.1 6.9 2.8 8.3 12.4 6.8 12.4 10.8 8.2 3.1 7.3 8.1 8.1 8.4 3.2 2.5 1.0

1.51

119.0

Source: D udley, B arre tt, and B aldock (1985), T able 6

to low -sulphur fuels to com ply with air-quality regulations (m any from coal to oil) - forced a m arked rise in th e price o f available low -sulphur coal and oil (L ynn 1976). A ny fu rth e r w idespread sw itching to low -sulphur fuels will force fu rth e r price rises th at could well m ake this a non-viable o ption. T h ere is also a technical lim itation in using low -sulphur fuel in conventional pow er statio n s, because such fuel d ecreases th e efficiency o f p recip itators, which are used to rem ove fly ash and particles from exhaust gases (P riest 1973). T h ere is th u s th e risk th a t increased reliance on low -sulphur fuels m ight reduce sulphur gas em issions but increase particulate pollution; th e trad e -o ff is o f q u estio n ab le value. B oth o p tions w ould reduce S 0 2 em issions from pow er statio n s, but most observers agree that em issions in E u ro p e and N o rth A m erica will only be reduced to an acceptable level if m ore co n certed efforts are m ade to rem ove the sulphur from fossil fuels and from em ission gases. T h ere are th ree m ain altern ativ es to choose from (P ersson 1976:249): reduce th e sulphur co n ten t of fuel before com b u stio n , reduce the pro d u ctio n o f S 0 2 during com bustion, o r reduce em issions o f S 0 2 a fter com bustion but before exhaust gases are em itted from chim neys into th e atm o sp h ere .

144 Acid Rain O ption 3. Fuel desulphurization T echniques are now available to reduce the sulphur co ntent o f fossil fuels before they are b urned, so that a given am ount o f desulphurized fuel will produce much less S 0 2 on com bustion than would the sam e am ount of uncleaned fuel. The sulphur content o f natural gas is routinely rem oved at source (Lynn 1976) and both oil and coal can also be ‘clean ed ’ (the latter is a bit less viable). T he two main m ethods involve eith er washing o r chemical rem oval of the sulphur. Coal washing has long been undertaken as a routine prep arato ry procedure to rem ove ash from freshly mined coal before it is tran sp o rted to pow er stations to be burned. But the washing also rem oves som e o f the pyritic sulphur from the coal (C larke 1985: 5) - a significant gain at m arginal cost so this process has been used in E urope and N orth A m erica to clean the coal before com bustion. W ashing has been m ore extensive in N orth A m erica because o f the higher sulphur content o f its indigenous coal. The econom ics of each colliery norm ally determ ine how much coal is washed o n s ite (M eetham et al. 1981:201). The process is simple and norm ally takes place at the coal preparation plant. Coal is crushed and ground into tiny (dust-sized) particles, then it is floated on w ater. The finely ground coal particles float, but the heavier m inerals sink. The washed coal is then dried in hot air: norm ally this is simply a stream o f hot exhaust gases derived from coal burning (around 2 per cent of the total coal stock is used for drying - Persson 1976: 249). The process is very efficient. W ashing rem oves up to 30 per cent o f the raw coal as ash rejects (Persson 1976: 249), and norm ally 40-60 per cent (by w eight) of its pyritic sulphur content (Tolba 1983: 118). But this often reduces the S 0 2 gas em issions from the coal by as little as 8 per cent (Persson 1976: 249) to 15 per cent (M eetham et al. 1981: 201), because washing rem oves only some of the inorganic sulphur, and it cannot rem ove any of the organic sulphur that is chemically bound to the coal (Priest 1973: 75). T he cost of washing crushed coal is relatively cheap - quoted values are in the range $1-6 per tonne of coal (T oiba 1983: 118) - but there rem ains som e doubt about the cost-effectiveness o f such treatm en t (Priest 1973: 75). Such doubts are amplified if the accounting is based solely on operating costs, and values are not attached to having clean air. Chemical cleaning m ethods for coal are as yet still being developed (T olba 1983:118), but they have the real advantage of rem oving both the organic and the inorganic sulphur from the coal (Persson 1976:249). T hey are also m ore expensive than washing - up to 95 p er cent o f the pyrites (inorganic) and half of the organic sulphur can be rem oved at a cost o f $20-30 per tonne of coal (Persson 1976: 249). W ashing adds 1-6 p er cent to electricity costs; chemical desulphurization adds 15-25 p er cent (T olba 1983: 118).

Cures and remedies Sulphur-rich coal can also be converted into a burnable gas o r a liquid, with the sulphur rem oved in the process (Priest 1973: 73). These processes are referred to respectively as gasification and liquefaction, and both can significantly reduce the sulphur content of the fuels. In the U nited States, w here natural gas reserves are very lim ited, large quantities of highsulphur coal have been converted to gas with the double advantage of reducing S 0 2 emissions and gaining more productive use o f available energy reserves (Lynn 1976). G asified coal is a relatively expensive fuel source (M eetham et al. 1981: 301). Liquid fuels can also be desulphurized; recent chemical advances m ake it possible to rem ove up to 99 per cent of the sulphur from most crude oils (M eetham et al. 1981: 301). D esulphurization of gas oil is now widely done in new refineries in E urope (Persson et al. 1976). U p to 80 per cent of the sulphur can also be rem oved from residual oil, but econom ic factors (it increases costs by 20-35 p er cent - Lynn 1976) dictate how widely this is in fact done. Because gasoline oil is so profitable, the U nited States produces relatively little residual oil; but many overseas refineries produce m ore and cheaper residual oil (some with a high sulphur content) (Lynn 1976). T he costs of desulphurization of liquid fuels ap p ear to be prohibitively high. E stim ates given to the 1982 Stockholm Acidification C onference (see chapter 8) suggest that it costs $20-40 per tonne of fuel oil to rem ove sulphur, which would add 10-20 p er cent to the cost of producing energy (Tolba 1983: 118). O n balance, therefore, fuel desulphurization is technically possible but economically questionable as a basis for reducing sulphur emissions at source. O ption 4. Sulphur reduction at com bustion The best alternative to using low -sulphur fuel is to use fuel with a higher sulphur content but ensure that most o f the sulphur is rem oved during com bustion - before it ever has the prospect o f becom ing an exhaust gas ( S 0 2) em itted from chimneys. This can be done using flu id ized bed technology (FB T ), which fixes sulphur to lime at the time of com bustion and ‘offers a prom ising way o f reducing pollution by both sulphur and nitrogen oxides in heat and pow er plants’ (T olba 1983: 118). FB T is a very efficient m eans of modifying com bustion to reduce S 0 2 production (Persson et al. 1976; A llar 1984; C larke 1985), but it requires a special type of boiler (the ‘fluidized bed boiler') in which the coal is burned. The process exploits the known buffering ability o f lim estone. Coal is fed into the com bustion cham ber from one side, and finely crushed lim estone (or a sim ilar m aterial capable of absorbing S 0 2 at com bustion tem perature) is fed in from the o ther. T hus the coal is burned in the presence o f lim estone. This takes place on a grate through which air o r gas is passed from below ; the turbulence causes constant agitation and thus com plete mixing o f the coal and lim estone (hence ‘fluidized b ed ’). This

146 Acid Rain mixing increases the efficiency o f the com bustion process (all o f the coal is burned properly), but it also ensures th at all o f the coal is exposed to the buffering agent during com bustion. T he buffer effectively strips the coal of its sulphur, form ing an ash residue (a m ixture o f calcium sulphate, calcium oxide, and calcium sulphide). T ests show that the fluidized bed technology is capable o f rem oving nearly all o f the sulphur in the fuel (Persson et al. 1976). T here are a num ber o f econom ic advantages in the FB T option. The technology is now comm ercially available to small and medium -sized plants, at costs com parable to conventional com bustion systems (Swedish M inistry of A griculture 1984). It involves no great additional capital expenses, thus is quite suitable for any new pow er stations th at might be planned (it is not an ‘add-on’ o r retrofit technology - like flue gas desulphurization (option 5) - which requires costly conversion o f existing plant). M oreover, the sulphur enriched lim estone ash is a saleable product, and can be used comm ercially as gypsum (Persson et al. 1976). B ut th ere are o th er advantages than simply the econom ic ones. Because the fuel is burned at a much low er tem p eratu re than in conventional boilers, emissions of N O x are also reduced considerably (Persson et al. 1976) (rate of production of N O x depends in part on com bustion tem p eratu re). T here is a growing belief that F B T is the m ost prom ising prospect for reducing S 0 2 from high-sulphur fuels, but the newness o f the technology cannot be overlooked. In som e senses it rem ains (in late 1987) a prospect, rath er than a reality, because although scale trials have proved successful there is still som e uncertainty over how costly, cost-effective, o r o p e r­ ationally reliable the technology will tu rn o ut to be. T he technology is believed to be feasible and econom ic in coal-fired pow er stations capable of producing up to 250 m egaw atts of energy (Swedish M inistry of A griculture 1984). E xperim ental work on fluidized beds, carried o ut on behalf o f B ritain, W est G erm any, and the U nited States, began in B ritain in the early 1970s. From 1980 onw ards testing has centred on a large trial furnace at G rim ethorpe Colliery, near Barnsley (Y orkshire) ( The Times, 25 May 1984, p. 14), and fu rth er evaluation tests by the C entral Electricity G enerating B oard and the N ational C oal B oard on larger boilers began in 1985. Pending the outcom e o f such tests, the long-term and w idespread applicability of FB T is difficult to judge.

O ption 5. Flue gas desulphurization O ne alternative to rem oving sulphur from coal during com bustion is to rem ove the sulphur gases produced in com bustion before they are released into the air (i.e. em itted from pow er station chim neys). This involves ‘effluent cleaning', o r - m ore correctly - flue (or stack) gas desulphuriza­ tion (F G D ), which is a relatively recent developm ent in comm ercially

Cures and remedies viable term s and still very much a new area o f research (M aurin and Jonakin 1970; Slack 1973). It is much m ore difficult to rem ove sulphur after com bustion than before or during because it is dispersed (in exhaust gases) rath er than concen­ trated (in coal). Sulphur gas is about a thousandth o f the density o f sulphur in solid form (M eetham et al. 1981; 201), so th at large volum es of exhaust gas with small concentrations o f S 0 2 in it have to be treated to rem ove equivalent am ounts o f the pollutant. F G D rem oves sulphur oxides from flue gases by chem ical reaction th at encourage absorption o f the sulphur on to a solid o r liquid. T here are th ree main techniques to choose from. T he dry regenerative approach involves passing the flue gas through a bed o f dry absorbant (such as activated carbon). T he absorbant reacts with the S 0 2, and by capturing and retaining the gas (on the surfaces of the particles) it prevents S 0 2 emissions in the flue gas. T he S 0 2 can be chemically rem oved from the absorbant, then converted into sulphur (S) o r sulphuric acid (H 2S 0 4) to be sold (Persson et al. 1976). T he process is ‘regenerative’ in the sense that it produces usable sulphur as a by-product, the sale o f which helps to offset the cost of rem oval (Priest 1973: 75). W et techniques have been used m ore extensively, and are likely to be adopted m ore widely in the future. In the wet regenerative approach the flue gas is passed through a liquid (the reagents are norm ally dissolved in w ater) in which the S 0 2 is absorbed. The sulphur, now in solution, can then be converted to yield saleable S o r H 2S 0 4 (Persson et al. 1976), again helping to offset costs o f rem oval. This technique is com m only referred to as ‘w et scrubbing’, and it norm ally involves bubbling the dirty flue gas up a packed tow er in which the contam inants are absorbed; clean (i.e. desulphurized) gas leaves the top of the tow er (O nnen 1972). T he wet non-regenerative approach involves passing the flue gas through a ‘scrubber’ containing a w ater slurry of lime o r lim estone. T he technique is also referred to as ‘lim estone scrubbing’ (Persson et al. 1976). T he S 0 2 and sulphate solids in the flue gas are rem oved by direct buffering on to the surface o f the lime o r lim estone particles, producing calcium sulphate (gypsum). This approach is non-regenerative because the absorbant (i.e. the slurry) is throw n away after use and its sulphur c ontent is not reclaim ed and reused. Lim estone scrubbing is the most comm on approach to effluent cleaning at present (T olba 1983: 118; M cCorm ick 1985). It also has a long history. L ondon’s B attersea pow er station (built in 1929) was the first installation in the w orld to have a successfully operating FG D system , which cleaned 80-90 per cent of the sulphur from the flue gas for most of its w orking life (Elsw orth 1984a: 61). Scrubbing equipm ent was also installed at Fulham pow er station (built in 1935) and at the oil-burning Bankside pow er station (built in 1954), both in London (M eetham et al. 1981). Scrubbing has som e distinct advantages. It can be an ‘add-on un it’ for existing pow er stations, so it does not require the building o f new stations. In fact in the U nited Kingdom all large m odern pow er stations are now

148 Acid Rain required, at the planning stage, to provide enough space on site for F G D to be installed (retrofit) if necessary (Elsw orth 1984a: 61). In addition, FG D does not require the electrostatic precipitators fitted to conventional pow er stations to reduce particulate emissions in flue gas (O glesby 1971; Perkins 1974:263). M oreover, it rem oves particulates and som e N O x from flue gas, as well as the S 0 2. But - as ever - these benefits are gained at a cost! Sludge disposal is a real problem . Large quantities o f wet sludge with no com m ercial use or value are produced (around half a ton n e of sludge - 60 per cent solid, 40 p er cent liquid - is produced per tonne o f coal; Persson et al. 1976), which generally has to be dum ped. A n o th er draw back is th at calcium is deposited on the equipm ent, which reduces its operating efficiency and requires regular cleaning (at a cost) (Lynn 1976). T he wet scrubbing process also reduces the tem perature of the flue gas, so the gas must be reheated (at a cost) after scrubbing to give it adequate buoyancy to ensure th at it does not fall to the ground close to the pow er station (Persson et al. 1976) (see Figure 2.7). W et scrubbing norm ally increases electricity costs by 8-18 per cent (H ighton and Chadwick 1982) and rem oves up to 70-90 per cent of the S 0 2 from flue gas (C larke 1985: 5). D espite its proven abilities, many large sources in the U nited States have been extrem ely reluctant to use FG D processes to reduce sulphur em issions, arguing that th eir feasibility is not yet fully established (Lynn 1976). They favour continued reliance on burning low -sulphur fuels (option 2) w ithout flue gas cleaning. This has increased dem and for rem aining low -sulphur fuel, pushed its price up, and made the long-term suitability of option 2 som ew hat questionable. O ption 6. Disperse flu e gases T here is an alternative strategy to reducing S 0 2 emissions from point sources, and that is to disperse the oxides over as wide an area as possible. This can be achieved by releasing flue gases into a region in the atm osphere where they will be relatively harm less, eith er by using tall enough stacks o r by building the pow er stations in rem ote places (M eetham et al. 1981). This was the thinking em bodied in the ‘tall stacks policies’ favoured in Britain and the U nited States som e tw enty years ago. But - as we have seen in chapter 1 - the approach is now regarded as unacceptable because, whilst it did serve to disperse gaseous emissions over a w ider area, that very process has played a key role in producing the acid rain th at is now so w idespread a problem (see Figures 2.6 and 2.7). It has turned w hat was previously a local problem o f dry deposition into a regional and trans-frontier problem o f wet deposition. It is difficult not to conclude, with the benefit o f hindsight, that this option contributes to rath er than helps to solve the problem s o f acid rain.

Cures and remedies Reducing emissions of NOx from power stations M ost atten tio n in th e acid rain d eb ate (see P art IV ) has rightly cen tred on reducing em issions o f S 0 2 from po w er stations. W hilst th e co n trib u tio n o f p ow er stations to N O x em issions (producing aro u n d 46 p e r cent o f th e m an-m ade N O x in the U n ite d K ingdom - F igure 7.1) is sm aller in term s of q uantities p ro d u ced (see T ab le 2 .2) and arguably less significant in term s o f biological effects (ch ap ters 4 and 5) an d dam age to buildings and hum ans (ch ap ter 6 ), it m ust n o t be o v erlo o k ed . N itrogen is not presen t in the fossil fuels b u rn ed in co n ventional pow er stations; it com es from th e air in tro d u ced during com bustion. C o n seq u en t­ ly, control technologies for th e reduction o f N O x m ust be applied during and a fter burning (C lark e 1985: 5); sw itching fuel sources o r cleaning fuel before burning have m inim al im pact on N O x em issions. M ost available techniques are based on relatively sim ple technologies and do n o t req u ire large capital costs. T h e re are five m ain optio n s (P erk in s 1974: 263), four of which reduce N O xem issions during burning. B ecause the nitrogen com es from a ir intro d u ced during com b u stio n , one approach (low excess air co m bustion) is to m inim ize th e a m o u n t o f air p resen t at the point o f com bustion. In m ost b u rn ers, th e re is norm ally 10-20 p er cen t o f excess air (i.e. a ir ad ditional to th a t req u ired ju st to com plete th e com bustion process). If this excess air can be reduced to a m inim um (ideally z ero ), th en N O x pro d u ctio n will be red u ced significant­ ly. Such reductions can be e n su red on oil- and gas-fired b oilers, and are also believed to be possible on coal-fired boilers. T h e rate o f productio n o f N O x also d ep en d s on th e com bustion te m p e ratu re in th e boiler. T h u s an altern ativ e ap p ro ach involves reducing the peak te m p eratu re w ithin th e b oiler. In two-stage c o m b u stio n , a b o u t 95 p er cent of the air req u ired for com bustion is released in th e boiler at th e b u rn er, and the rest is in jected above th e b u rn e r (to com plete com bustion at stage tw o). T his red u ces the p eak flam e te m p e ra tu re , an d can reduce N O x production in gas- and oil-fired boilers by up to 35 p er cent. A variant is to m o d ify burner design to allow fo r tangential firing; h ere th e b urners are located in the corners o f th e bo iler, and they fire at a tan g en t to a circle in th e centre o f the furnace. B ecause the flam es in th e co rn er-fired boiler interact with one a n o th e r less th an in a conventional b o iler, com bustion is m ore efficient and it can tak e place at a low er peak te m p eratu re . N O x production is reduced accordingly, som etim es by up to 30-40 p e r cent (C larke 1985:5). In flu e gas recirculation a p o rtio n o f th e ex h au st gas is piped back to th e com bustion cham ber. T his flue gas has a very low oxygen c o n te n t, so its presence in the ch am b er reduces peak te m p e ra tu re . N O x pro d u ctio n can be reduced by up to 90 p e r cent by sim ple recirculation o f th e flue gas. T h e final option involves reducing N O x levels after burning, by flu e gas cleaning. It is m uch m ore difficult to rem ove N O x th an S 0 2 from flue gas, partly because N O x are very stable (th u s they do n o t react very readily with

150 Acid Rain absorbants) and partly because they are present in much sm aller concentrations (about one-third o f the SC)2 levels). A s noted above ( S 0 2 option 5), som e o f the N O x com ponent o f flue gas can be rem oved in lim estone scrubbing. But the technique is of lim ited effectiveness norm ally only about 20 p er cent can be rem oved (Perkins 1974). T he control techniques for rem oving N O x from pow er stations and industrial boilers are thus o f variable effectiveness. T hose that involve m odifications o f the com bustion process seem to hold o ut most prom ise for the future (Perkins 1974).

Reducing emissions of NOx from vehicles A lthough it is difficult to arrive at precise figures, it is estim ated that just over half (51 per cent) of the m an-m ade N O x in the U nited States (Lynn 1976:63) and around 28 per cent o f the m an-m ade N O x in the U nited K ingdom (Figure 7.1) com es from tran sp o rt, being em itted in the exhaust gases o f vehicles (m ostly from petroleum engines). T h ere is a much larger n um ber of non-stationary sources o f N O x than stationary sources o f S 0 2, each one contributing a tiny fraction o f the overall pollution budget. N O x sources are therefore much m ore widely dispersed and m ore m obile; N O x production is m ore variable through time and from place to place. T here are a num ber of strategies for reducing N O x emissions from vehicle exhausts. H ere is not the place to explore in great detail the technology o f vehicle engines (Lynn 1976: 238-43), but we should note the main pollution control alternatives. Vehicle m anufacturers in the U nited States have, since the late 1960s, w restled with the problem of m eeting increasingly stringent federal pollution-control standards. C onsequently the U nited States enjoys a m onopoly on initiatives and practical experience in this field. O ption 1. M odify engines or exhausts to reduce emissions T he two most com m on approaches (Lynn 1976; Strauss and M ainwaring 1984; M cCorm ick 1985) are eith er to rem ove o r alter the pollutants within the exhaust system , by installing appropriate technical devices, o r to alter the operation o r design of the engine to minimize production o f the pollutants in the first place. Much o f th e early research (especially in the U nited States during the 1960s) was directed tow ards the form er, and involved m ufflers and after-burn systems. These proved not to be entirely successful in reducing emissions o f N O x and o th e r pollutants, and so attention has m ore recently been redirected tow ards changes in engine design. As with N O x production in pow er stations and industrial boilers, rates of production of N O x in conventional (petrol-based) vehicle engines d epend largely on the am ount o f air present at the tim e o f com bustion. This can be altered by adjusting the air-fu el ratio , which is defined as 'th e n um ber of pounds of air used to burn each pound o f fuel’ (Lynn 1976: 248). The

Cures and remedies optim um efficiency in a conven tio n al engine occurs with an a ir-fu el ratio o f 15 (th e so-called ‘stoichiom etric p o in t’), but th e ratio varies w ith m ode o f o p eratio n o f the engine (m axim um pow er for acceleration com es at a ratio o f 12-13, econom ical cruising at steady speed has a ratio above 15). M ost early vehicle pollution co n tro l legislation in th e U n ited S tates (during the 1960s) focused on reducing em issions o f carbon m onoxide (C O ) and h ydrocarbon s (th e la tte r play a role in form ing p h oto-oxidants like o zone, hence in form ing acid rain - see Figure 2.6). T his could be done by adjusting the air-fu e l ratio tow ards the chem ically op tim u m level o f 15. B ut at th at point increased com bustion efficiency raises th e te m p e ra tu re o f com bustion; consequently w hen C O and h y d rocarbon em issions are low, the form ation o f N O x is at a m axim um (L ynn 1976: 248). A s a resu lt, nitrogen dioxide em issions increased while atte m p ts w ere m ade (by optim izing engine efficiency) to m eet th e C O and hydro carb o n stan d ard s. A n altern ativ e em ission red u ctio n approach had to be sought by th e autom obile industry w hen th e first A m erican N O x stan d ard s w ere in tro d u ced , in C alifornia in 1971. It was based on recirculating p a rt o f the exhaust gases back into the engine and mixing th em with the incom ing air. A s in th e N O x ‘flue gas recircu latio n ’ o ption o u tlin ed abo v e, this reduces the oxygen level in the com bustion ch am b er, low ers th e te m p e ratu re of com bustion and thus red u ces the u ltim ate p roduction o f N O x. A s vehicle N O x em ission stan d ard s in th e U n ited S tates becam e m ore stringent th ro u g h the 1970s, fu rth e r changes w ere req u ired . T h ese include m ore com plex controls to vary th e air-fu el ratio (especially tow ards m ore ‘lean b u rn ’ m ixtures, w hich have m ore air relative to fuel) an d m odified ignition system s. M o reo v er, ad ditional devices had to be fitted to m ost cars. T he m ost com m on was to replace the co n ventional ex h au st m uffler w ith a catalytic co n v erte r in th e exhaust p ip e, which w ould fu rth e r oxidize th e incom pletely bu rn ed C O an d hyd ro carb o n s to C 0 2 and w ater and thus reduce em issions. O ption 2. C hange to a different type o f engine T h ere are, o f course, o th e r ways o f reducing N O x em issions from vehicle exhausts (L ynn 1976). O n e strategy is to switch from th e conventional petrol-driven (liquid gasoline) engine to o th e r types o f engine. O n e option h ere is to m ake m ore use o f altern ativ e form s o f in tern al com bustion engine, such as liquefied p etro leu m gas (L P G ), w hich allow s m ore efficient com bustion and significantly red u ces C O an d h y d rocarbon em issions but on its ow n w ould do little to solve th e N O x problem . A n o th e r o p tio n is to use a ro tary ra th e r th an th e co n ventional in ternal com bustion engine; th e fou r-stro k e W ankel engine is a possibility th a t w ould produce m uch less N O x but m o re C O and h y d ro carb o n s. Y et o th e r optio ns include the m ore w idespread use o f diesel an d electric form s of vehicle pow er, and o f novel form s o f p ow er, such as gas tu rb in e o r steam (R ankine-cycle) engines.

152 Acid Rain T hese types o f altern ativ e offer su b stitu te m eth o d s o f providing pow er in vehicles, but no n e looks likely to replace the co n ventional in ternal com bustion engine as the m ain m e th o d , at least in th e n e a r fu tu re. A n u m b er o f factors explain this a p p a re n t in ertia, including econom ic and technical lim itations o f th e m ain altern ativ es. T h e re is also a m arked reluctance am ongst pu rch asers o f vehicles (p riv ate and institu tio n al) to thin k seriously ab o u t th e altern ativ es, especially in a clim ate o f free choice and w hat is assum ed to be the unproven reliability and viability o f m ost of the alternatives (the ‘W hy change if you d o n ’t have to ’ m entality). O ption 3. Transport planning T h e re is grow ing aw areness th a t en lig h ten ed tra n sp o rt p lanning can m ake a substantial co n trib u tio n to th e red u ctio n o f N O x em issions from vehicles. O ne m eans o f achieving this is to im prove th e flow o f traffic in congested areas; pollution levels are red u ced if b o ttle-n eck s and traffic ja m s are m inim ized. N O x em issions rise sharply as vehicle sp eed increases, so th a t traffic planning designed to cut dow n on high-speed vehicle m ovem ents (an d p ro p e r legal en fo rcem en t o f u p p e r sp eed lim its) w ould also m ak e a co n trib u tio n to th e problem . T ra n sp o rt planning is m ost successful in reducing pollu tio n from vehicle exhausts w hen it seeks to cut dow n on th e n u m b er o f vehicles on th e road in an area by providing ‘mass tra n sit' altern ativ es. T h e o b jectiv e h ere is to encourage private car users (w ho o ften travel alo n e, o r p erh ap s with one passenger - both extrem ely inefficient m odes o f trav el) to use public tran sp o rt system s, especially du rin g ru sh -h o u r co m m u ter trips to/from busy city centres. O bvious exam ples include th e rap id rail tran sit system s in m ajo r U S cities (such as N ew Y o rk , B o sto n , an d San F ran cisco ), th e heavily used co m m u ter train s in L o n d o n , E n g lan d , an d lim ited stop c o m m u ter buses to/from m any m a jo r cities in E u ro p e and N o rth A m erica. Providing the m ass tran sit a ltern ativ e to th e p riv ate c ar is o n e thing; encouraging com m u ters to use it is a n o th e r. O ld habits die h ard , and - like sluggish snails in th eir com fo rtab le shells - co m m u ters doggedly stick to th eir ow n m ode o f tran sp o rt for co m fo rt and convenience (d esp ite its heavy relative cost). In som e cities co m m u ters are e n co u rag ed to sw itch to m ass transit system s (o r at least to car-sh are schem es) by various m easu res, such as heavy costs o r lim ited availability o f city-centre parking. P riority schem es have also been talk ed a b o u t, in which access to a given p art o f a city is lim ited on certain days to certain cars. A n in terestin g exam ple o f such a schem e in p ractice is A th en s, G reece (D icks 1985). T he city has long suffered from thick sm ogs (n e fo s) which env elo p it for m uch o f the year. W hen n efo s is p articularly b a d , private cars w ith o d d and even n u m b er plates are b an n e d from th e city c en tre on a lte rn a te d ates; private cars have also been excluded com pletely from central A th e n s fo r lim ited trial periods. Such traffic m an ag em en t schem es have num erou s ad v an tag es o th e r th an

Cures and remedies the reduction o f N O x em issions and prev en tio n o f severe pollution episodes. T h ese include red u ced overcrow ding in city cen tres, red u ced ro ad rep air and m ainten an ce costs, red u ced need to set aside land for car parking and for (m ulti-lane) highw ay co n stru ctio n , reduced accident rates and hu m an stress, and d ecreased public travel costs. All in all, these are valuable savings, w h eth er costed in purely econom ic term s o r in term s o f im proved quality o f life, and this o ption is likely to be pu rsu ed m ore widely in the future.

CONCLUSIONS Prevention is better than cure, in pollu tio n control as in o th e r aspects o f life. W hilst it is possible to ‘c u re ’ som e o f th e w orst biological effects o f acidification by adding lim e o r lim estone to affected lakes, soils, and forests, such rem edial action offers at best a palliative. Lim ing does not offer a viable long-term solution. T h e only acceptable solution is to m ake sure th a t em issions o f th e su lp h u r an d nitrogen oxides th a t provide th e precursors to acid rain are red u ced to acceptable levels. T his ch ap te r has explo red th e m ain optio n s for reducing em issions o f S 0 2 and N O x from pow er statio n s, industrial po in t sources, and vehicles. W e conclude th at viable an d technically effective m etho d s o f controlling and reducing such em issions already exist, and th at fu rth e r optio n s p erh ap s even m ore viable in econom ic bo o k -k eep in g term s - a re on the horizon. Such m ethods, applied sep arately o r in com bination (as circum st­ ances d ictate) can bring red u ctio n s to agreed levels w ithin agreed tim e-scales. 'E n erg y conservation and the sub stitu tio n o f alternatives to fossil fuels m ust be com bined with th e d esulphurization o f fuels and stack gases in o rd e r to arrive at th e o p tim u m strateg y ’, argued G o ran Persson o f the Swedish E nvironm en t P ro tectio n B oard (P ersson et al. 1976:249). P ro o f th at a solution to th e oxide em ission p roblem exists, given political recognition o f th e pro b lem and w illingness to tackle it, com es from Ja p an (L a Bastille 1981: 680). In 1968 the Jap an ese go v ern m en t issued strict S O x controls and encouraged th e use o f low -sulphur fuels and desulp h u rizatio n . By 1975 sulphur oxide em issions had halved, even as energy consum ption d oubled. Since 1975 even stricter controls have been set, and by 1982 nearly 1,200 scrubbers had been fitted in Jap an (co m p ared with aro u n d 200 in the U n ited S tates). T h e problem is thus n o t a technical o n e; it is essentially a political one (see P art IV ). U nless th ere is g enuine political goodw ill (and th e sustained public pressure to ensu re th is), th e acid rain ‘p ro b lem ’ - w hich can be solved - will n o t be solved. T h e cen tral questio n is w h eth er to spend the vast sum s required to em b ark on long-term oxide em ission p ro g ram m es o f the scale called fo r in th e E E C D irective (i.e. a 60 p e r cen t red u ctio n in S O , levels by 1995). B ut the high cost o f cleaning up is in no sense ‘m oney dow n th e d ra in ’, because m ost if not all o f th e costs m ay be offset by positive side-effects

154 Acid Rain such as the creation o f new jobs and generation o f useful by-products (such as com m ercial sulphuric acid) (La Bastille 1982:680), not to m ention the savings to be gained on corrosion o f m aterials (chapter 6), th e values of conserving fish (chapter 4), forests and crops (chapter 5), and the benefits in im proved hum an health (chapter 6). As we shall see in the next ch ap ter, the reluctance of the U nited States and B ritain to join the o th er ‘30 per cent club’ countries and curb sulphur and nitrogen oxide emissions rests in part on the questionable non-linearity of response o f acid rain to oxide emissions (see ch ap ter 3) and in part on their failure to accept (or to be convinced by) available scientific evidence (see Part II) th at acid rain is actually causing the dam age to the environm ent widely attrib u ted to it.

Part IV THE POLITICS OF ACID RAIN

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8 INTERNATIONAL CONCERN AND INITIATIVES The acid rain storm. . .

W hat is this, th e sound and ru m o u r? W hat is this th a t all m en h e a r, L ike th e w ind in hollow valleys w hen th e storm is draw ing n ear, Like the rolling on o f ocean in th e even tid e o f fear? ’Tis th e p eop le m arching on. (W illiam M orris, C han ts for Socialists, ‘T he m arch o f the w o rk ers’, 1885) R ecent prolonged drou g h ts in the Sahel and in E th io p ia in A frica, with untold and seem ingly relentless h um an m isery and dep riv atio n and a massive hum an d eath toll, reinforce o u r heavy reliance on th e rainfall th a t perm its land to sustain life. N ow here on e a rth can life survive fo r long w ithout S h ak esp eare’s ‘gentle ra in ’ which ‘d ro p p e th . . . from h eav en ’ {M erchant o f Venice, IV , i, 182). B ut it is not sim ply the quantity o f rainfall th a t m atters; the quality o f th a t rain is highly im p o rta n t as well. W e have seen in P art II how rain th at is m ore acid th an n orm al can seriously affect rivers an d lakes (an d th e life w ithin th e m ), soils, forests, crops, buildings, an d stru ctu res, even th e health and survival o f hum ans. W e have also seen (in P art I) how hum an activities cause at least p a rt o f the acidification o f rainfall th at causes these p roblem s, and (in P art III) th a t th ere are techniques available th a t can reduce this acidification. L ittle w onder, th erefo re, th at th e re is m ounting concern to do som ething about the acid rain p ro b lem , and to do it w ithout fu rth e r delay. In this P a rt we shall ex plore th e ro o ts o f this in terest and exam ine how it has em erged and been ex p ressed , especially since th e mid-1970s. W e begin, in this c h a p te r, w ith a g eneral review o f th e in tern atio n al d eb a te , before m oving on to exam ine in closer detail th e n atu re o f the d eb a te in the U SA (ch ap ter 9) and in G re a t B ritain (c h ap ter 10).

THE DEBATE OPENS - EARLY MILESTONES A s we n oted early in ch a p te r 1, acid d eposition is n o t new . W et deposition was first described by R .A . Sm ith in M an ch ester as far back as 1852, and dry deposition has long affected m any o f th e w o rld ’s m ajo r cities. W hat is

158 Acid Rain new is the depth of interest in the issue, arising from the grow th o f wet deposition and the spread of acid rain over much o f w estern E urope and N orth A m erica (see Figure 1.1).

Scandinavian concern Acid precipitation was long seen as a problem lim ited to Sweden and Norway (Paulsson 1984). M any lakes there w ere turning acidic and losing their fish populations in the 1920s and 1930s (see ch ap ter 4), but the cause of the acidification rem ained at the tim e an unsolved mystery. T he possible link with acid precipitation started to em erge when first results appeared from the E uropean A ir C hem istry N etw ork (E A C N ), which had been started in the 1950s by Sweden (by the International M eteorological Institute in Stockholm ) (O den 1976; G ran at 1977). By 1955 it was clear (from E A C N observations) that precipitation over large parts o f E urope was unusually acidic (E gner and Eriksson 1955). W ithin fifteen years the data were to show that rainfall acidity was increasing (i.e. its pH was falling), and the area over which acid rain was falling was also increasing. A m ajor breakthrough cam e in 1968, when the Swedish scientist Svente O den reported increased acidity o f lakes in southern Scandinavia (which was seen to be closely associated with large-scale fish deaths (O den 1976). But the main significance o f O d en ’s study was th at it show ed that the most likely cause of the acidification was airborne sulphur th at had been blown over to Scandinavia from o th er countries (mainly E ast and W est G erm any and G reat B ritain). This was the first tangible evidence th a t acid deposition is a serious international problem , but at the time the study was greeted with m arked indifference by the scientific world and m arked silence by politicians beyond Scandinavia. Only later was it to be hailed as a m ilestone in air pollution research, and given the w ider recognition it so clearly deserved.

Watershed year -1972 T here was m ounting evidence by 1972 (especially from E A C N ) th at the precipitation in E urope was becom ing increasingly m ore acidic, and it was becom ing clear th a t som ething must be done. It was to be a year of significant developm ents, literally a w atershed in the acid rain saga. The U nited N ations C onference on the H um an E nvironm ent - itself a m ilestone in environm ental diplom acy (W ard and D ubos 1972) - was held in Stockholm from 5 to 16 June. A wide range of environm ental problem s were discussed by delegates from many countries; this was the first serious international dialogue on many pollution issues. Sw eden used the distinguished gathering as a platform from which to air its growing concern over acid rain and to launch its since o ft-repeated call for p ro p er control of long-range sulphur pollution. Few countries to o k th e call seriously,

International concern and initiatives especially those (like Britain and W est G erm any) who were accused as m ajor sulphur em itters. H ow ever, one tangible outcom e of the Stockholm C onference was the unanim ous adoption o f twenty-six general principles relating to protection of the environm ent in and betw een UN m em ber states. Perhaps the most im portant is Principle 21, which declares: States have, in accordance with the C h arter of the U nited N ations and the principles o f international law, the sovereign right to exploit their resources pursuant o f their own environm ental policies and the responsibility to ensure that activities within th eir jurisdiction o r control do not cause dam age to the environm ent o f o th er states o r o f areas beyond the limits o f national jurisdiction. (U N G eneral A ssem bly, D ocum ent A /Res/2997, xxvii, 15) The O rganization for E conom ic C o-operation and D evelopm ent (O E C D ) took an im portant initiative th a t sam e year by launching a co-operative program m e to m easure the Long-R ange T ran sp o rt o f A ir Pollutants (L R T A P ) (O ttar 1976). It involved a netw ork o f abo u t seventy ground stations, which took daily m easurem ents o f air quality (O tta r 1976); results were reported each m onth to the Norwegian Institute for A ir R esearch, which took responsibility for analysing the results (R eed 1976). This was the first m onitoring devoted specifically to acid precipitation, and it has yielded invaluable inform ation. H ow ever, simply m easuring the acidity of rainfall does little to help understanding o f how acid rain affects the environm ent. T he Scandina­ vians had by 1972 collected sufficient evidence o f acid dam age to forests and freshw ater lakes and rivers to realize that it was becom ing an environm ental problem o f m ajor significance, about which m ore should be know n. Norway took the lead in starting a detailed research p roject on the effects of acid precipitation on forest and fish (A braham sen et al. 1976). T he project (widely referred to as the SNSF Project) was funded jointly by the Norwegian Council for Scientific and Industrial R esearch, the A gricultural R esearch Council o f N orw ay, and the N orwegian M inistry of E nvironm ent. It was initially planned to run from 1972 to 1975, but later extended to 1979.

Increasing awareness Early results from the SNSF Project were p resented at an International C onference on the Effects o f Acid P recipitation, held in T elem ark, N orw ay, from 14 to 19 June 1976 and atten d ed by delegates from tw enty countries and six intergovernm ental organizations. The conference recom ­ m ended that ‘all governm ents reconsider their approaches to the control of the emission o f relevant pollutants, bearing in mind the available range of technical solutions. A reduction o f emissions would also have beneficial effects in areas close to the emission sources’ (A non 1976).

160 Acid Rain By 1977 th ere w as no d o u b t th a t long-range tra n sp o rt o f su lp h u r dioxide and acid p o llu tan ts did occu r across E u ro p e , an d th a t this tra n sp o rt in u p p er air w inds had no resp ect fo r national bo un d aries. O E C D studies, u n d er the L R T A P p ro g ram m e (O rg an izatio n fo r E conom ic C o -o p eratio n and D evelopm en t 1977), had established th a t th e region receiving rainfall ten to thirty tim es m o re acidic th an norm al had grow n to include th e eastern half o f B ritain , m ost o f cen tral E u ro p e , an d Scandinavia up to n orth-central Sw eden and F inland (see Figure 2.3). T hey had also established th a t som e co u n tries e x p o rt acid rain , whilst o th e rs im port it. F or exam ple, it was discovered th a t u n d e r certain cond itio n s up to h alf o f B ritain ’s sulphur em issions (m ainly from p o w er statio n s) w ere e x p o rted to o th e r E u ro p ean co u n tries (w ho w ere, n o t surprisingly, not am u sed at th eir uninvited im ports!). R eliable evidence from N orth A m erica has only been collected since 1977, w hen th e C an ad ian A tm o sp h eric N etw ork fo r S am pling A ir P ollutants (C A N S A P ) began; the U S N ational A tm o sp h eric D eposition Program sta rte d in 1978 (W helpdale 1983:73). D ata from each reinforced the lack o f respect o f th e o xide-bearing w inds for political o r adm inistrative b oundaries. By th e late 1970s th e re w as also a b e tte r aw areness th at e a rlie r air p ollution control strateg ies in th e U K and U SA (th e ‘tall stacks p olicies’ see ch ap te r 1) had been successful in reducing sm oke p ro b lem s, but - by dispersing gaseous p o llu tan ts dow nw ind - had seriously ag gravated conditions in rem o te areas up to th o u san d s o f kilo m etres away. W hat w as becom ing a p p a re n t w as th a t the problem o f acid rain cannot be solved at a n ational level. A s th e Sw edes had arg u ed at S tockholm in 1972, w hilst national initiatives can m ak e significant co n trib u tio n to reducing em issions and thus d eposition rates, th e p ro b lem is truly trans-n ational in ch arac te r an d scale. In tern atio n al co -o p eratio n is n eed ed if the problem is to be resolved.

THE GAME PLAN UNFOLDS B efore we exam ine how this in tern atio n al co -o p eratio n beg an , it is useful to tak e stock o f th e im plications o f the evidence on precip itatio n acidity th at had been collected from th e m o nitoring program m es th a t began in the 1970s in E u ro p e and N o rth A m erica. A n ote o f cau tio n is a p p ro p ria te , because even by th e late 1980s it is difficult to secure reliable d irect m easurem ents o f rate s o f su lp h u r em ission an d d eposition from m any areas and som e countries; the evidence is at best patchy and o f variable quality (despite in tern atio n al schem es designed to harm onize p ro ced u res and in stru m en tatio n ). T h e problem is u n d erstan d ab le, given th e massive n u m b er o f sm all industrial and d om estic sources o f S 0 2, th e m obility o f vehicle sources o f N O x and S 0 2, and th e variability th ro u g h tim e in em issions from large sources o f S 0 2 (m ainly pow er statio n s).

International concern and initiatives Differing estimates A n u m b er o f estim ates o f rates o f em ission an d d eposition have b een m ade since the early 1970s, and o ften th e figures are not identical from on e study to an o th er. T his partly reflects th e fact th a t rates o f em ission and deposition w ithin a coun try change th rough tim e (see, fo r exam p le, Figures 1.5 and 2.5). B ut it also reflects th e fact th a t high-quality d a ta , based on direct m easu rem en t, are sim ply n o t available fo r som e co u n tries; estim ates are all we have to go on. T he best in form ation available to d a te com es from the U nited N ations E conom ic C om m ission fo r E u ro p e (E C E ) E u ro p ean M onitoring and E valuation P rogram m e (E M E P ) (D o v lan d and S altbones 1979), the W orld M eteorological O ffice B ackground A ir Pollution M onitoring N etw ork (B A P M O N ) (G eorgii 1981), th e C an ad ian A tm o s­ pheric N etw ork fo r Sam pling A ir P ollutants (C A N S A P ), and th e U nited S tates N ational A tm osp h eric D eposition Program (N A D P ). A lthough th e absolute values q u o ted for each cou ntry vary betw een surveys (e.g. the 1973 O E C D results (see T ab le 8 .1), Sw edish estim ates for 1980 - Swedish M inistry o f A gricu ltu re 1984, and th e E M E P d a ta for 1980 (see T able 8 .1 )), m ore tim es th an not th e co u n tries m aintain th e ir positions relative to each o th er. In o th e r w ords, the sam e co untries ten d to em erge as bad polluters in each study. T h u s, fo r exam p le, the U K , W est G erm an y , and F rance rem ained the ‘to p th re e ’ g roup b etw een the 1973 and 1980 estim ates (T able 8.1), even th ough th e absolute values o f th e estim ates increased by m ore than tw o-thirds o v er th e perio d . T h e m ost com prehensive d a ta are available for 1980 (although m ore recen t d ata are available fo r so m e co u n tries), and this is a convenient ‘base T able 8.1

Changing estimates o f sulphur emissions in Europe, 1973-80

Country

Total emission o f S 0 2 per country (thousand tonnes) 1973 OECD est. 1980 EM EP est.

% change 1973-80

Austria Belgium D enm ark Finland France N etherlands Norway Sweden Switzerland U nited Kingdom W est G erm any

221 499 312 274 1,616 391 91 415 76 2,803 1,964

440 809 437 595 3,270 480 137 496 119 4,680 3,200

+ 99 + 62 + 40 + 117 + 102 + 23 + 51 + 20 + 57 + 67 + 63

Total

8,662

14,633

+

69

Source: based on Organization for Economic Co-operaiion and Development (1979) and EMEP data in McCormick (1985)

162

Acid Rain y ea r’ to use for com parisons. T able 8.2 lists estim ated rates o f S 0 2 em ission by country in th a t year (based on E M E P m easurem ents), an d F igure 8.1 show s em issions in E u ro p e estim ated by a m odelling p ro ced u re. A gain, absolute values v aried , but relative positions rem ain ed relatively stable betw een the tw o. It is clear th a t th e re are tw o m a jo r em itte rs o f S 0 2 - R ussia and the U nited S tates - w hich, betw een th e m , acco u n ted for half Table 8.2

Estimated rates o f emission o f S O 2 by country, 1980

Rank

Country

SO 2 emissions (thousand tonnes)

% o f total deposition fro m within that country

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

USSR* USA China U nited Kingdom* C anada E ast Germany* Italy* France* W est Germany* Czechoslovakia* Yugoslavia* Poland*' Spain (1985) Hungary* Turkey Bulgaria* Belgium* Greece* Finland Sweden Netherlands* Austria Denm ark* Romania* Portugal Ireland* Norway Switzerland Albania* Luxembourg* Iceland

25,000 24,100 12,000 4,680 4,516 4,000 3,800 3,270 3,200 3,100 3,000 2,755 2,730 1,633 1,000 1,000 809 700 (est.) 595 496 480 440 437 200 170 170 137 119 100 (est.) 50 10

53 ? ? 79 50 65 70 52 48 37 51 42 63 42 42 45 41 37 26 18 23 15 36 36 27 28 8 10 15 27 0

Estim ated total for E E C (*) Estim ated total for N orth America Estim ated total for Eastern E urope (*) Estim ated world total Source: based on EMEP data in McCormick (1985)

17.6 million tonnes 28.6 million tonnes 40.8 million tonnes around 100 million tonnes

Figure 8.1 E stim a te d su lp h u r dioxide em issions in E u ro p e , 1980 (m illion to n n e s p e r year)

WE S T GERMANY

FRANCE

CZECHOSLOVAKIA

YUGOSLAVIA

SPAIN

HUNGARY BULGARIA

BELGIUM

| SWEDEN

| FINLAND NETHERLANDS

H

DENMARK

| |

AUSTRIA

|

RUMANIA

| REPUBLI C OF I RE L AND

fNORWAY

]SWITZERLAND

|a

l b a n i a

Source:

based on d ata in Eliassen and Saltbones (1983)

164 Acid Rain of the world m an-m ade output (T able 8.2). T he ‘top ten ' countries accounted for nearly 88 per cent o f the world total. Little w onder, therefore, that many countries look tow ards these heavy polluters to face up to their responsibilities and cut S 0 2 emissions to reduce acid rain.

Give and take T he data show th at most countries in E urope and N orth A m erica receive acidified rain (defined as rain with a pH below 5.6 - see Figure 2.1), but th at levels of acidification vary from place to place (K allend et al. 1983) (see Figure 1.1) and through time (R odhe and G ran t 1984) (see T able 2.1 and Figure 2.2). In each country, at least part of the acid deposition comes from sources within that country - i.e. it is ‘hom e-grow n’ pollution. B ut the sulphur and nitrogen oxides can travel long distances before they fall to the ground (see Figure 2.7), so that acid rain can be exported from one country to another (dow nwind). O E C D data show that som e of the sulphur that falls on E u ro p e’s w estern seaboard might well have been transported across the A tlantic from eastern N orth A m erica ( The Tim es, 12 June 1984); up to a q u a rte r of N orw ay’s sulphur receipts are believed to com e from C anada and the U nited States. Studies of A rctic haze in A laska (ch ap ter 3) also suggest long-distance tran sp o rt o f pollutants, perhaps from sources in n orthern Russia. C onsequently som e countries tend to be net im porters whilst o thers are net exporters of acid deposition. T he clash o f self-interest betw een the exporters (who are happy to get rid o f the S 0 2) and the im porters (who are reluctant to receive it) is the central pivot of the acid rain deb ate. T he records show th at B ritain, W est G erm any, Italy, and several E astern E uropean countries export large am ounts o f sulphur pollutants, whilst the Scandinavian countries receive much m ore from abroad than they produce them selves (Figure 8.2). M any o f the m ajor im porting countries are m em ber states o f the E uropean Com m unity (T able 8.3), and their growing frustration at taking in th eir neighbours’ ‘dirty w ashing’ has acted as an im portant catalyst in prom oting E E C initiatives in air pollution control. B ut the tension betw een im porters and exporters is not confined to W estern E urope. A num ber o f countries in E astern E urope im port m ost of their S 0 2 from their neighbours (Table 8.3). In N orth A m erica, large am ounts of sulphur pollutants are believed to be blown into eastern C anada from the E astern U nited States (see ch ap ter 9), although it is clear that C anada does produce a fair proportion (around half) o f its own acid rain (Table 8.2). T he m ajor em itters (Table 8.2), and those who receive relatively little S 0 2 from o th er countries (Table 8.4), tend to view the acid rain problem especially from an international perspective - with much less urgency than those who im port it. R ecipients suffer the consequences (in term s o f acid

International concern and initiatives Figure 8.2 1980

E stim a te d rate s a n d p a tte rn o f d ep o sitio n o f su lp h u r o v e r E u ro p e ,

Source: based on EMEP/ECE data, after Environmental Resources Ltd (1984) Note: Showing the estimated average monthly rate of deposition (in hundreds of tonnes) and estimated percentage of deposition that is imported from other countries. The percentage values shown differ slightly from those in Tables 8.2 and 8.3 becausc they arc based on different data sets.

d a m a g e - se e P a r t I I) o f w h a t th e y see as u n sc ru p u lo u s e x p o rtin g a n d im m o ra l in d iffe re n c e by d o n o rs .

Table 8.3

Major importers o f SO 2 , 1980 % o f sulphur deposition im ported fro m foreign sources

Country Switzerland* Austria* Luxembourg* N etherlands* Albania* Norway* Sweden* R om ania1 Czechoslovakia* Finland D enm ark Belgium Poland* Hungary* Greece* Canada

78 76 73 71 67 63

58 56 56 55 54 53 52 52 51

around 50

Source: based on EMEP data in McCormick (1985) Note: the data in this table and Table 8.2 do not add up to 100% because some proportion of the deposition remains unaccounted for in each country. * EEC countries; f Eastern European countries (see Table 8.2).

Table 8.4

Countries that receive least S 0 2 fro m foreign sources, 1980

Country U nited Kingdom* Spain Italy* Iceland E ast Germany* USSR* Ireland* Portugal France* Turkey Yugoslavia* W est Germany* Bulgaria*

% o f sulphur deposition im ported fro m foreign sources 12 18 22 25 32 32 32 33 34 39 41 45 47

Source: based on EMEP data in McCormick (1985) Note: relevant data not available for USA. * EEC countries; f Eastern European countries (see Table 8.2).

International concern and initiatives INTERNATIONAL INITIATIVES ECE LRTAP Convention (1979) International initatives began in 1979, when the E C E - a different body altogether from the E uro p ean Econom ic Com m unity (E E C ) - d rafted a C onvention on the Long-R ange T ransport o f A ir Pollutants. The L R T A P C onvention was formally signed by thirty-five countries (Table 8.5) in G eneva, on 13 N ovem ber 1979. It aim ed to encourage a co-ordinated program m e of pollution control in E u ro p ean countries, designed to reduce emissions of sulphur dioxide and thus to curb acid rain (for the benefit of all countries in E urope). T he C onvention has an interesting background, because it grew o ut of an initiative by Soviet President Leonid Brezhnev at the 1975 H elsinki C onference on Security and C ooperation in E urope (R osenkranz 1983:5). Given this strong Soviet stake in its adoption, the ap parent reluctance of E astern E uropean countries (including Russia) to ratify it, and their notable absence from the 1982 Stockholm C onference on Acidification of the E nvironm ent, seem to reflect a m arked change o f heart. T he C onvention was designed as an ‘outline convention’, not a legally binding docum ent detailing required action by the individual countries. It outlined the general responsibilities o f the signatory states to put limits on trans-frontier air pollution (covering all types o f air pollutants, not just sulphur), and reiterated Principle 21 from the 1972 Stockholm C onference on the obligation of states to ensure th at activities within th eir own territories did not give rise to environm ental dam age in o th er countries. Signatory states agreed to five things (Swedish M inistry of A griculture 1984): (a) recognition that airborne pollutants are a m ajor problem (b) declaration that they w ould ‘endeavour to limit and, as far as possible, gradually reduce and prevent air pollution, including long range trans-boundary air pollution’ (c) intention that they would use ‘the best available technology which is economically feasible’ to achieve (b) (d) intention to act together to work o ut guidelines and strategies for better control o f emissions and pollutants (e) intention to develop technical and scientific co-operation (e.g. in m onitoring effects and m easuring emissions). It was hailed at the tim e as a turning point in international air pollution control; E rik L ykke, N orw ay's M inister o f E nvironm ent, added ‘I ’m praying that this C onvention will bring a cleaner landscape 10 to 15 years from now ’ (La Bastille 1981:685). But the agreem ent was soon to be heavily criticized as ‘not sufficient’ because it ‘m akes only vague recom m endations’ (L a Bastille 1981:685). It set no targets for emission

168

Acid Rain Table 8.5 1987

Com m itm ent o f countries to the 1979 L R T A P Convention, by start o f

Signatory A ustria Belgium Bulgaria Byelorussian SSR C anada Czechoslovakia D enm ark Fed. R ep. G erm any Finland France G erm an D em . Rep. G reece Hungary Iceland Ireland Italy Liechtenstein Luxem bourg N etherlands Norway Poland Portugal R om ania San M arino Spain Sweden Switzerland Turkey U krainian SSR USSR U nited Kingdom USA Vatican Yugoslavia EEC

Date o f ratification

Date o f accession

Promised S 0 2 reduction fro m 1980

Dec July June June Dec Dec June July A pr Nov June A ug Sept May July July Nov July July Feb M ar Sept

1982 1982 1981 1980 1981 1983 1982 1982 1981 1981 1982 1983 1980 1983 1982 1982 1983 1982 1982 1981 1985 1980

June June June June June Sept June June June M ar June

50% 50% 30% 30% 50% 30% 50% 60% 50% 50% 30%

June Feb May A pr June May July Nov

1982 1981 1983 1983 1980 1980 1982 1981

1983 1984 1984 1984 1983 1984 1983 1983 1983 1984 1984

A pr 1985

Sept June June M ar June

1984 1984 1984 1984 1983

by by by by by by by by by by by

1995 1995 1993 1993 1994 1993 1995 1993 1995 1990 1993

30% by 1993

30% 30% 30% 40% 50%

by by by by by

1993 1993 1993 1995 1994

June 1983 June 1983

65% by 1995 30% by 1995

June 1984 June 1984

30% by 1993 30% by 1993

July 1982

Source: Acid News (1985), volume 4, page 3

reductions, intro d u ced no m achinery for m aking com pliance m an d ato ry , and set no tim etable. T h e initial im petus was soon to be lost; co u n tries sta rted to realize the type and scale o f sacrifices th a t w ould be expected o f them if they pressed ah e ad w ith th e initial intentions. T h ere was to be a delay o f th ree an d a half years - th ree an d a half years of grow ing fru stratio n fo r S candinavian

International concern and initiatives countries and o f heart-search in g for m any o th e r signatories - before enough countries ratified th e C o n v en tio n , and it could com e into force (in M arch 1983).

Stockholm Conference on Acidification (1982) By early 1982 th e E C E C o nvention still lacked th e necessary tw enty-four ratifications, so it had not yet com e into force. M o reo v er, even if it were to com e into force w ithout fu rth e r delay , th ere w ere still no co n crete plans on the horizon to reduce p o llution. F ru stratio n was m ost acute am ongst the Scandinavian countries. T he Sw edish governm en t took the lead, in Ju n e 1982, by hosting a large intern atio n al congress on acid rain. It was held on th e ten th anniversary of the 1972 U N C onference on th e H um an E n v iro n m en t. F u rth er poignancy was added by the fact th at it was held in S tockholm , scene o f S w eden’s 1972 call for internation al action to cut S 0 2 em issions. T h e general aim o f the M inisterial C onferen ce on A cidification o f th e E nv iro n m en t was to heighten aw areness o f th e w hole acid rain p ro b lem . B ut it had two very specific aim s - to encou rag e enough ratifications to bring the C onvention into force, and to enco u rag e n ational and in tern atio n al action to reduce S 0 2 em issions and curb acid deposition. T h e form al m eeting was p reced ed by a g ath erin g o f in tern atio n al experts (scientists and technicians) w ho ‘threw dow n th e g a u n tle t’ to th e m inisters and diplom ats to thin k seriously a b o u t action w ith th eir th re e main conclusions (Sw edish M inistry o f A g riculture 1984). T h ey ag re ed , first, th at we do know enoug h a b o u t th e n atu re and effects o f acid rain to tak e rem edial action - co n trary to th e o u td a te d b elief hung on to by m any politicians th at th ere w ere still to o many u nresolved scientific q uestions. T h eir second conclusion w as th a t all m easures th a t reduce to tal em issions will also reduce the dam age now being do n e by acid rain to sensitive lakes and stream s - even if th e link is not linear. T hey also ag reed th a t curren tly available control technologies can reduce em issions, and at an acceptable cost - the norm al caveat ad d ed by political decision m akers. T h e M inisterial C onferen ce w as atten d e d by rep resen tativ es o f tw entytw o o f the thirty-one m em b er states o f th e U N E conom ic C om m ission for E u ro p e w ho h ad originally signed th e 1979 L R T A P C o nvention (P earce 1982c; R osenkranz 1983). Several rep resen tativ es ech o ed Sw eden’s call for concerted in tern atio n al action to bring th e E C E C o nvention into o p eratio n w ithout fu rth er delay. T h e m eeting agreed th a t u rg en t action should be ta k e n u n d e r the C onvention on L ong-R ange T ran sb o u n d ary A ir P o llu tio n , including: • establish and im plem ent co n certed program m es to reduce S 0 2 a n d , as soon as possible, N O x em issions • use the best technology available th at is econom ically feasible to reduce these em issions, taking account o f th e need to m inim ize th e p roduction o f w astes and pollution in o th e r ways

170 Acid Rain • support research and developm ent of advanced control technologies • further develop the N orth A m erican m onitoring program m es and E M E P , through b etter geographical coverage, im proved data on em issions, standardizing sam pling and m easurem ent techniques, and im proved m odelling. H ow ever, there w ere three significant features of the C onference that attracted particular interest in the m edia. Perhaps the most interesting feature o f the m eeting was th e largely unexpected about-turn in attitudes tow ards acid rain shown by W est G erm any. W est G erm any, one o f the largest polluters in E u ro p e (Table 8 .2) and thus a notable bete noire, had long been on the receiving end of the Scandinavian campaign to limit oxide emissions. It had also presen ted a host of objections to , and been a som ew hat reluctant signatory of, the E C E C onvention in 1979. B ut now it em erged in support of the Scandinavian call for international action, and it took a visibly active stance and adopted a high profile. In terio r M inister G erh art Baum called on all the nations attending the m eeting to fight air pollution at source, using the best available technology. He urged them to follow his country’s exam ple and equip new and rebuilt plants with best available pollution-control technology (flue gas desulphurization (F G D ) - ch ap ter 7). H e also pledged his governm ent’s com m itm ent to a 60 per cent reduction in S 0 2 emissions from pow er stations and large factories by 1993. This 60 p er cent target was to be achieved by a program m e including introducing m andatory use of F G D systems on new and existing installations, am ending the country's basic clean air regim e, requiring the latest state o f technology in all installations, and prom oting an EEC -w ide strict regulation on m otor vehicle emissions (aim ed at reducing N O x by 50 p er cent). W est G erm any was the first m ajor E u ro p ean polluting nation to join Scandinavian countries as an ally in th eir fight against trans-boundary air pollution and acidification of the environm ent. T he prim ary reason for this sudden about-turn was the discovery o f the serious dam age being caused to their own forests ( Waldsterben - chapter 5), so there was clearly m ore than a little self-interest given the econom ic significance o f the cou n try ’s forests and tim ber industry. T he direct trigger for the change in heart was the growing influence and rising m em bership o f the G reen P arty, reflecting a rem arkable grow th o f strength of the environm ental m ovem ent in W est G erm any. Acid rain ‘becam e a potent political issue and in the elections which took place [early in 1983], hard en ed politicians swiftly announced their conversion in the face of persistent cam paigning by the “g reen ” p arty ’ (A cid N ews, 1984, 4, p. 3). This ‘greening’ of W est G erm any was a significant landm ark in the developm ent o f public environm ental aw are­ ness in E urope (P orritt 1984). T he second feature o f the C onference was the m arked absence o f most E astern E uropean countries, despite the strong Soviet vested interest in adoption o f the C onvention (recall the B rezhnev 1975 initiative). East

International concern and initiatives G erm any was the only m ajor E astern E u ro p ean polluter to attend. Bulgaria and three o f the e ast’s heaviest polluters - Poland, C zechoslova­ kia, and the Soviet U nion (T able 8.2) - boycotted it altogether. H ungary and R om ania - relative 'sm all fry’ in the international league (Table 8.2) were present but played no active role in d ebate. This exhibition of indifference alarm ed and annoyed many delegates who w ondered about the extent to which E astern E uro p ean co-operation in the E C E schem e could be counted on. T he third m ajor feature - of equal international significance to the W est G erm an about-turn - was the self-im posed isolation o f the U nited States and the U nited K ingdom . From the outset each country was clearly prepared to m ake few concessions; neither governm ent sent its senior m inister. T he U nited K ingdom , rep resen ted by G iles Shaw (Parliam entary U nder-Secretary of State for the E n vironm ent), argued th at th ere was still too little certainty about the benefits o f new control program m es to justify new control m easures. T he U S A , represented by M rs K athleen B ennett (A ssistant E nvironm ental Protection Agency A d m inistrator for Noise and R adiation), argued that fu rth er m easures to reduce acid deposition should n ot be taken until ongoing research was com pleted. These two argum ents both essentially aim ing to buy time - were to be rehearsed many tim es in public, at national and international m eetings, by both governm ents in the years ahead (see chapters 9 and 10). T he final statem ent o f the C onference was strong and positive. It concluded that further concrete action was required to reduce S 0 2 and N O x emissions, using the best available technology that was economically feasible. It also concluded that FG D had been proved as the best technology for S 0 2 control and it should be used in new and rebuilt installations (especially pow er stations). Significantly, in light o f the scientists’ views, the final statem ent stressed that any reductions in emissions would benefit sensitive areas. By now the sides were well and truly lining up for the public international deb ate. T he good guys had distinguished them selves from the bad guys, and the battle was under way.

GROWING AWARENESS AND HEATED EXCHANGES (1983) The public interest in acid rain, which had started in Stockholm in 1982, was given further m om entum the next year with the discovery o f dam age (especially to trees) in many countries across E urope. By early 1983 the Swiss governm ent was voicing alarm at evidence of dam age to trees in the Swiss A lps, and im m ediately attrib u ted it to acid rain (A c id N ew s, 1983, 2, p. 14). Plans w ere swiftly draw n up for the Swiss Federal Institute o f Forest Research to prepare a Swiss N ational Forest Inventory (1983-6), which would be updated every five to ten years. In W est G erm any, authorities were both am azed and alarm ed at the speed with which forest death (W aldsterben) appeared to be spreading (see Figure 5.5). Soon forest dam age attrib u ted to air pollution was being reported from

172 Acid Rain A ustria (w here around 11 per cent o f the country’s total forest area was showing signs of dam age). T rees in France also appeared to be under attack, in an alm ost unbroken strip running from B rittany in the west to the Vosges in the east, also in central France and the Pyrenees. Symptoms were sim ilar to those being reported from W est G erm any (see Figure 5.4), Sw itzerland, and A ustria (A c id News, 1984, 2, p. 9). Serious national attem pts to curb emissions also began in 1983. D enm ark’s Socialistic Folkesparti proposed to the Danish parliam ent that acidification o f the environm ent should be reduced (A c id N ew s, 1983, 4, p. 8), mainly by installing F G D equipm ent in m ajor pow er stations. It was estim ated that this would add 2-3 p er cent to electricity costs b u t reap much m ore in benefits from reduced corrosion, b ette r harvests, and reduced hum an health problem s. T he proposal was rejected by the governm ent, pending the outcom e of studies then under way by the E nvironm ent B oard.

Launching of LRTAP By early 1983, tw enty-four o f the original thirty-five signatories had ratified the 1979 E C E L R T A P C onvention (Table 8.5), which could then come into force on 15 M arch (A c id News, 1983, 1, p. 2; The Times, 15 M arch 1983, p. 13). Im plem entation of the C onvention was to be overseen by an Executive Body (E B ), which included representatives o f thirty-four individual countries and the E E C that had signed it. T he first m eeting o f the EB was held in Brussels from 7 to 10 June 1983. M any participants w ere well aw are of the inherent w eakness o f the C onvention as originally form ulated, in that it lacked specific pollutioncontrol targets (by quantity and d ate). Some took the initiative and offered firm proposals (A c id News, 1983, 5, p. 12). T he Swedish, N orw egian, and Finnish governm ents subm itted a proposal suggesting that total emissions of sulphur from each individual country should be reduced by 30 per cent betw een 1983 and 1993. C anada, D enm ark, A ustria, Sw itzerland, and W est G erm any supported the th ree N ordic countries. Sw itzerland, A ustria, and W est G erm any also subm itted a proposal designed to reduce N O x em issions, which was supported by C anada and the N ordic countries. No action was taken on eith er proposal. Some countries (e.g. the U SA ) expressed their general approval o f the proposals but disapproved of specific num erical targets. T he EB em erged as a body willing to m ake general statem ents and to entertain acid rhetoric, but most reluctant to set specific targets for reducing trans-boundary air pollution. It was widely viewed as a toothless watchdog, and many environm entalists bem oaned its ap p aren t inertia. Some were even angered at the low level of reductions called for in the Nordic proposal - N orw ay’s Stop Acid R ain Cam paign quickly announced th at ‘the N ordic governm ents are being too cautious. It is not sufficient to dem and that E uro p ean countries should reduce th eir air pollutants by 30 per cent in the space of ten years. If the fishkill in Scandinavia is to be

International concern and initiatives sto p p ed , acid rain m ust be red u ced m ore drastically th an this, an d at once (A c id N ew s, 1983, 4, p. 5). T hey q u o ted th e 1981 O E C D study, which show ed th at a 50 p e r cen t reduction in W estern E u ro p e ’s S 0 2 em issions was possible ov er ten years, at a cost o f aro u n d US$12 p e r person p e r year (a 2 .5 -3 .5 p er cen t rise in energy costs).

Publicity and awareness A ctivities to build public aw areness and vent public frustratio n also started in 1983, especially in W est G erm an y w here th e ravages o f Waldsterben w ere widely publicized. E arly in th e new year a new enviro n m en tal action group (called ‘R obin W o o d ’) (A c id N ew s, 1983, 2, p. 3) was form ed with around 100 m em bers (including fo rm er G re en p eace activists). Its aim was to carry out a range o f activities designed to bring acid rain to the forefront of public in terest, via the m ass m edia. T h e ir first m ajo r day o f action was 21 F ebruary, w ith activities plan n ed for five m ajo r G erm an cities, includ­ ing the occupation o f pow er station flue stacks (in B erlin and C ologne) and the ‘p lanting’ o f dead trees in tow n cen tres (in Kiel and B rem en). Building public aw areness was also a keen issue in S candinavia, w here m any initiatives to bring acid rain issues before the g eneral public w ere launched. In A p ril, th e Swedish S ecretariat on A cid R ain pro d u ced a four-colour ‘N o a h ’s A rk ' p o ster (arguing th a t ‘if acidification is allow ed to co ntin ue, we shall soon have to build a new N o ah ’s A rk ’). Its text was prin ted in E nglish, G erm a n , Sw edish, D u tch , and N orw egian, and it was to be d istributed (free) w idely (A c id N ew s, 1985, 2, p. 2). O th e r free and widely circulated Sw edish m aterial included a g eneral leaflet on acid rain aim ed at foreign tourists visiting Sw eden, which was p ro d u ced by the N ational Swedish E n v iro n m en t P rotection B oard (in English and G e r­ m an), and an illustrated b o o k let ‘A cidification - a boundless th re a t to o ur en v iro n m en t’ p roduced by th e Swedish M inistry o f A griculture (also in English and G erm an ) (A c id N ew s, 1983, 4, p. 12). A Swedish film o f acid rain (‘A n o th e r Silent S pring’) won prizes at large in tern atio n al film festivals in C zechoslovakia and th e N eth erlan d s, and it was subsequently released with soundtrack s in E nglish, G e rm a n , F ren ch , D an ish , D utch, Italian , G re e k , and Swedish (A c id N ew s, 1983, 5, p. 9). T he In tern atio n al Y o u th F ed eratio n for E nviro n m en tal Studies and C onservation (IY F ) (fifty youth o rganizations concerned with natu re conservation and th e en v iro n m en t) decla red 18-24 A pril to be 1983 In tern atio n al A cid R ain W eek (A c id N ew s, 1983, 1, p. 2; 1983, 2, p. 4). T heir objective was to en co u rag e groups to d ev o te them selves to acid rain issues over th a t w eek and to carry out activities (e.g. article w riting, public m eetings) designed to increase g en eral public aw areness o f th e problem s involved. T h e ultim ate goal w as to m ould public opinion tow ards suppo rting control m easures an d to m obilize public su p p o rt for letter w riting, cam paigning, and lobbying in o rd e r to provide th e political m om entum fo r acid rain to be tak en seriously by national governm ents.

174 Acid Rain International debate International deb ate continued in Brussels (19-20 A pril), when the E uropean Parliam ent C om m ittee on the E nvironm ent, Public H ealth and C onsum er P rotection held a public hearing on acid deposition (A cid N ew s, 1983, 2, p. 2). It was addressed by a series o f experts (in forestry, soils, and w ater) and by representatives from six organizations - the E uropean E nvironm ental B ureau (E E B ), E uropean electricity producers (U N IP E D E ), B ritain’s C entral Electricity G enerating B oard (C E G B ), the O rganization for Econom ic C o-operation and D evelopm ent (O E C D ), the U nited N ations Econom ic Comm ission for E urope (U N E C E ), and the U nited N ations E nvironm ental Program m e (U N E P ). All agreed that the adverse effects o f acid rain were clear, and the deb ate centred not on w hether o r not to reduce emissions b ut on how it should be done and who should pay for it. Views were strictly polarized. Industry and electricity producers (concerned only with the costs rath er than the benefits of pollution control) failed to accept the need for fast action and pointed instead to the need for fu rth er research. T he environm ental organizations and most researchers took the opposite view: action was needed urgently (especially to reduce emissions by 50 per cent in th e next five years), with energy conservation and use o f alternative (low-sulphur) fuels as top priorities. T he debate and concern were not confined to E urope. M ustafa T olba, executive director of U N E P , singled out acid rain as one o f th ree key issues in his official annual U N E P report The State o f the W orld E nvironm ent 1983, published to coincide with W orld E nvironm ent D ay (5 June) (A cid N ews, 1983, 4, p. 2). H e saw acid rain as a ‘particularly m odern, post-industrial form o f ruination . . . it is as w idespread and careless o f its victims and of international boundaries as the winds th a t disperse it’. ‘The only lasting solution’, he argued, ‘is to reduce the emissions of the pollutants in the first p lace.’ L ater in the year, E uropean farm ers and forestry ow ners joined the growing chorus of groups requesting wholesale cuts in oxide em issions. A resolution to control pollutants at source was adopted unanim ously by the 35th G eneral Assem bly o f the E u ro p ean C onfederation o f A griculture, held at W iesbaden, W est G erm any, 26-30 S eptem ber (A cid N ew s, 1984,1, pp. 14-15). In the sam e m onth, a consensus em erged at the E uro p ean Com m unity m eeting in K arlesruhe, W est G erm any, th at the E E C should take w hat action it could w ithout delay, and th a t m easures should include cutting em issions o f S 0 2 from pow er stations (A cid News, 1984, 1, p. 1).

ACTIONS AND DECISIONS (1984) T he m om entum gained in the international acid rain d eb ate during 1983 was to be taken much further in 1984. T he first moves w ere taken in late January, w hen the E uropean parliam ent was p resented with a rep o rt on

International concern and initiatives dam age from acid rain prepared by its E nvironm ent C om m ittee {Acid N ews, 1984, 2, p. 2). It stressed th at most estim ates o f the cost o f acid rain dam age (e.g. the 1981 O E C D estim ates o f £33-44 billion p er year across E urope) erred on the low side because they did not take into account dam age to forests (especially in W est G erm any). The rep o rt called for a program m e of international action to com bat the m enace of acid rain, including strict emission standards, increased research effort, and a long-term com m itm ent to reduce oxide emissions. It argued th a t the heavy cost of clean up should be m et at least in part by im posing a special levy on those who produce the oxides (the ‘polluter pays’ principle). W ithin days, in early F ebruary, the Parliam entary C om m ittee of the Council of E urope, then in session in S trasbourg, was reading a report presented to it by its C om m ittee on R egional Planning and Local A uthorities. This recom m ended th at the Council should prepare a proposal for a E uropean C onvention to determ ine limits for air pollution emissions (to be signed by non-m em ber countries as well as by m em bers), in o rd er to strengthen the 1979 E C E C onvention. It advocated the need drastically to reduce emissions o f S 0 2 (by at least 50 p er cent) and N O x (by 90 p er cent). The report also urged further research and b ette r inform ation exchange betw een m em ber states. E arly in the year, therefo re, the stage had already been set for further dialogue on the trans-national im plications o f acid rain, and the calls for concerted efforts in E urope had begun. T he urgency of the situation was to becom e even m ore ap p aren t in the following m onths, as reports of acidification dam age continued to come in from many countries - clearly the dam age was not going to stop, even if m om entum in coping with it was at tim es put into a state o f suspended anim ation.

Damage spreads By mid-1984, the state o f W est G erm any’s forests appeared to have deteriorated considerably. Unofficial estim ates w ere suggesting that around half o f the country’s forest land was being affected, at a cost in the region o f DM 7-10 billion per year (A c id N ew s, 1984, 1, pp. 6-7). By now the detectable forest dam age was also spreading through Scandinavia, w here fish deaths and lake acidification had been the m ajor headache for over a decade. Public concern was great in Sw eden when it was revealed that up to 10 p er cent o f the trees along som e parts o f the country’s west coast were showing similar signs of dam age to those rep o rted from central E urope {A cid N ews, 1984, 1, pp. 8-9). T he possible econom ic conse­ quences w ere not lost in a country in which 300,000 people are em ployed in a forestry industry w orth over 50 billion Swedish kroner. Similar signs w ere appearing in N orw ay, particularly in the south where up to 30 per cent of the trees in the county of V est-A gder had dam aged tips

176 Acid Rain (A cid N ews, 1985, 1, p. 3). Lake dam age was also starting to em erge in Finland. A bout half o f the lakes in the w estern p art o f Nyland province (west o f H elsinki) eith er show ed signs o f acidification o r had low buffering capacities and w ere under th reat (A cid N ews, 1984,4, p. 12). T ree dam age was also reported in softw oods (m ainly pines) along the west coast of D enm ark (A cid N ew s, 1984, 2, p. 10), and fu rth er south in L uxem bourg (w here the sam e rep o rt spoke of 19 p er cent o f the trees being dam aged, 4 p er cent badly). F u rth er south again, some 34 per cent o f the trees in Sw itzerland w ere found to be dam aged ^8 per cent badly), mainly in the southern A lps (A cid News, 1985, 1, p. 9). E astern E urope was not escaping the ravages of acid rain. T ree dam age was described over an area o f nearly 4,000 sq. km in Poland, and fears w ere expressed that this would rise to nearly 30,000 sq. km if Poland pressed ahead with its industrialization plans w ithout pollution control (A cid N ew s, 1984, 4, p. 5; K asina 1980). A ir pollution was particularly bad (ten tim es the w orld average) in Czechoslovakia, and by mid-1984 som e 37 p er cent of its forests w ere eith er dead o r spoiled beyond repair (A cid N ew s, 1985,1, p. 9). The tree death toll in C zechoslovakia was expected to rise to 60 per cent by the year 2000 if no action was taken to reduce oxide emissions and thus curb air pollution.

Political steps U nilateral decision m aking to reduce oxide emissions also started in 1984. T his was a significant step forw ard for the individual countries with the vision and conviction to m ake th eir own com m itm ents, and a strong catalyst for the international deb ate th at was by now coming to the boil. In F ebruary, France announced its intention to reduce its emissions of S 0 2 by 50 per cent by 1990 (over 1980 levels) (A cid N ews, 1984, 3, p. 6), echoing W est G erm any’s earlier declaration o f a similar 50 per cent reduction. In D enm ark, the official report of a Comm ission on A cidification specially appointed by E nvironm ent Secretary C hristian C hristensen proposed reducing D en m ark ’s S 0 2 emissions by 30 p er cent (from 1980 levels) by 1995 (A cid N ews, 1984, 2, p. 10). This would cost an estim ated 3-4 billion in D anish kro n er 1986-95 (around 50 D anish k ro n er p er year for the average fam ily), and be achieved mainly by reducing the acceptable sulphur levels in heavy and light fuels and by fitting F G D technology to pow er stations. N orw ay’s E nvironm ent Secretary R akel Surlein announced her governm ent’s intent to reduce S 0 2 em issions by 50 per cent, mainly by im posing tougher rules on use of high-sulphur fuel oils and by introducing catalytic exchange cleaning on al! new m o to r vehicles (from 1988) ( A d d N ew s, 1984, 2, p. 11). Sw itzerland, now alarm ed over the extent o f its own forest dam age, aim ed its control m easures m ore tow ards N O x from vehicle exhaust emissions - it im posed strict speed limits (effective from 1 January 1985) of 120 kph (kilom etres p er hour) on m otorw ays (down from 130 kph), 80 kph

International concern and initiatives on open highw ays (from 100 k p h ), and 50 kph in built-up areas (from 60 kph) (A c id N ew s, 1984, 5, p. 11). H ow ever, the w illingness to act unilaterally was not sh ared by all E u ro p ean countries. F o r exam p le, Belgium - which was seeing m ounting evidence o f acid dam age and facing rising public interest in acid rain - had announced (on W orld E n v iro n m en t Day 1983) a pro g ram m e to reduce S 0 2 em issions by 30 p er cent betw een 1980 and 1993; yet by th e end o f 1984 no concrete policy proposals had been forthcom ing. C ritics o f this ‘fence sitting' p osture a ttrib u te d the lack o f action to th e slow pace of governm ent actio n , the stren g th o f th e c o u n try 's p ro -n u clear lobby, and the reluctance o f industry and energv pro d u cers (A c id N ew s, 1984, 5, p. 15). By this tim e, the scale and significance o f the acid rain problem in E u ro p e w ere clear to all, even those co u n tries relu ctan t to act directly in reducing oxide em issions. A lso beyond do u b t was the tran s-fro n tier ch aracter o f the p ro b lem , in which som e co u n tries gained (they exported unw anted air pollutants) w hilst o th e rs lost (they im p o rted them ) (Figure 8.2). It was obvious to E u ro p e an scientists and politicians th a t concerted international action w as now req u ired . Tw o highly significant dev elo p ­ m ents follow ed in M arch.

EEC Directive O n 1 M arch 1984 the C ouncil o f M inisters o f th e E E C C om m ission in B russels ad o p ted a fram ew ork D irective designed to reduce em issions o f pollutants from large com bustion plants and to regulate those from vehicle exhausts (A n o n 1984/5f). T h e D irective req u ired th a t th e re should be provision for C om m unity-w ide em ission limits, based on th e best available technology, not involving excessive costs, and taking into account the natu re and qualities o f th e em issions concerned. T h e first proposal (C om m ission o f th e E u ro p ean C om m unities 1984b, c) covered 'large com bustion p lan ts’, which included p o w er statio n s, m etal m anufacturing and processing, chem ical w orks, th e food industry, and w aste disposal installations. It laid dow n specific limits for th e em ission o f S 0 2, N O x, and dust from all new plants with a th erm al o u tp u t o f 50 m egaw atts o r m o re, to be applicable from Jan u ary 1985. F o r existing plants it advocated the setting up o f national o b jectives by each m em b er state for the reduction o f total annual em issions. T he req u ired reductions - 60 p e r cent for S 0 2, 40 p e r cent fo r NO* an d 40 p e r cen t for dust - w ere to be achieved by D ecem b er 1995. T h ese targets w ere sim ilar to those already ad o p ted in W est G erm any. T he vehicle exhaust proposal (C om m ission o f the E u ro p ean C om m uni­ ties 1983, 1984a) argu ed th a t all m em b er co u n tries o f the E u ro p ean C om m unity should intro d u ce regulations sim ilar to those in the U nited S tates (the so-called US-83 regulations) for cleaning m o to r vehicle exhausts, by 1995 o r earlier. It also argued th at m em b er co u n tries should

178 Acid Rain m ake unleaded p etrol generally available from th e begining o f 1989 o r earlier. T h e proposals received a m ixed reactio n . Som e co u n tries h erald ed them as a realistic targ et. E ven B ritain saw them as a step forw ard; W illiam W aldegrave told the H ouse o f C om m ons on 5 M arch th a t they 'p ro v id e a consistent fram ew ork for fu tu re proposals on con tro l o f em issions from specific industries which will tak e full account o f th e need to balance econom ic, technical and environm ental facto rs' (E u ro p e a n C om m unities B ackground R ep o rt ISEC/84/84). O th ers sh ared th e view o f th e E u ro p e a n E nvironm ental B u reau , which w elcom ed th e C om m ission’s proposals but ‘feared th at [they] create expectations which it can n o t live up to , even w hen fully im plem en ted - the targ et and d ate p ro p o sed are to o low and too la te ’ (A c id N ew s, 1984, 3, pp. 10-11). T hey favoured a 50 p e r cent reduction o f S 0 2 em issions w ithin five years, then a fu rth e r 50 p er cent reduction in the follow ing five years (i.e. a 75 p e r cent d ro p in ten years).

Ottawa Ministerial Conference A lso in M arch, C an ad a hosted the In tern atio n al C o n feren ce o f M inisters on A cid R ain, which took place in O ttaw a. D eleg ates a tten d e d from A u stria, D en m a rk , W est G erm an y , F inland, F ran ce, th e N eth erlan d s, N orw ay, Sw eden, and S w itzerland, as well as C an ad a (A n o n 1984/5f; The T im es, 23 M arch 1984). T h e air was thick with good in ten tio n s (for exam ple, N orw ay p resen ted a p roposal to get in tern atio n al ag reem en t on a 50 p er cent reduction in S 0 2 em issions by 1993 - A c id N ew s, 1984, 2, p. 11), b ut caution was not in sh o rt supply. T he m inisters unanim ously su p p o rted a com m unique urging all signatories o f th e G en ev a L R T A P C onvention to get dow n seriously to th e business o f tackling in tern atio n al air pollution by reducing tran s-b o u n d ary fluxes o f S 0 2 and N O x by at least 30 p er cent by 1993 (from 1980 levels); th e ‘30 p e r cen t clu b ’ was form ally born in O ttaw a. A prim e purpose o f the tw o-day C o n feren ce was to g en e ra te pressure o f public and diplom atic opinion on b oth the U n ited S tates an d the U n ited K ingdom to join th e club. France and th e N eth erlan d s an n o u n ced that they w ould jo in ; the U SA and the U K again refused (T able 8.5). A n Internation al Acid R ain W eek (2 -8 A pril) was d esig n ated , as in 1983, by IY F. Its aim was again to cre a te large-scale publicity on problem s o f acidification, w ith th e hope o f influencing decision m akers to reduce em issions o f the p o llu tan t oxides. M any activities w ere o rganized in E u ro p e, including d em o n stratio n s in Sw itzerland, F inland, and B ritain. T housands o f postcards dem an d in g rapid steps to reduce em issions w ere sent from Sw eden, F inland, N orw ay, and the N eth erlan d s to g o vernm ents o f the large em itte r co u n tries (A c id N ew s, 1984, 1, p. 2; 1984, 2, p. 4).

International concern and initiatives Munich International Conference W ithout doubt the highlight o f 1984 was the m ultilateral ministerial m eeting held in M unich from 24 to 27 June. Signatories of the 1979 L R T A P C onvention and international governm ent organizations were invited to attend; all accepted and m inisters and officials from thirty-tw o countries were present. The initative for the International C onference on E nvironm ental Protection cam e from W est G erm an C hancellor H elm ut Kohl {Acid News, 1984, 2, p. 8). This was a classic ‘poacher turns gam ekeeper' tactic, in which the country previously criticized as a m ajor pollution exporter turned into a leader of the cam paign for suitable international action. H err Friedrich Z im m erm an, W est G erm any’s M inister of the Interior, com ­ m ented during the opening session th at ‘next to the strengthening o f peace, environm ental protection is the most im portant task of o u r age’ ( The Times, 26 June 1984, p. 6). G rowing aw areness o f the extent o f forest dam age in the country (especially from 1983 onw ards) was an inevitable catalyst. The m eeting had two main aims - to exchange views and research findings on dam age from acidification and experiences of how to com bat air pollution at source. B ut there was also a third item on the ‘hidden agenda', and that was to ‘oil the w heels’ of the international political m achinery in the hope o f speeding up progress on im plem enting the L R T A P C onvention. In this latter aim the Munich m eeting met with some success. The political m om entum was already under way, because ten countries (C anada, W est G erm any, France, Sw eden, N orw ay, D enm ark, Finland, the N etherlands, A ustria, and Sw itzerland) had already com m itted them selves (at the March m eeting in O ttaw a) to a 30 per cent reduction in S 0 2 emissions. Belgium , Luxem bourg, and Liechtenstein announced at Munich that they would join the ‘30 per cent club' (A cid News, 1984, 3, p. 4). Eastern E uropean countries were split in their willingness to com m it them selves to the 30 per cent targ et, which by then was being accepted as viable, if far from ideal, as a basis for reducing dam age from acid rain. Some of the east’s largest em itters o f S 0 2, including C zechoslovakia, Poland, H ungary, and R om ania, w ere most reluctant to m ake such com m itm ents, even though each adm itted having evidence of acidification dam age within its borders. O thers were m ore forthcom ing, largely reflecting their growing anxiety over the visible dam age to lakes and forests (for exam ple, extensive liming of fields was being u ndertaken in the USSR by this time - A cid N ews, 1984, 4. p. 5). H ow ever, th eir decision also highlights keen political astuteness in showing willing in the arena of international diplom atic d eb ate at a time when the o th er ‘super pow er’ (the U SA ) was clearly dragging its heels and being plain uncooperative. The U SSR, E ast G erm any, Bulgaria, and the Soviet republics o f Byelorussia

180 Acid Rain and the U kraine each co m m itted them selves to a qualified acceptance of the 30 p er cent ta rg e t, by agreeing to cut th eir S 0 2 exports (n o t em issions) by 30 p er cent by 1993. By the close o f play at M unich, th e re fo re, eig h teen nations had u n d ertak en to reduce th eir S 0 2 em issions by 30 p e r cent by 1993, so w ere in th e ‘30 p er cen t clu b ’ (T able 8.5). T his was a great advance from th e start o f play (ten n atio n s), but som e o f the h o ttest co n testan ts had escaped unscathed. Five co u ntries betw een them p ro d u ce th e bulk o f W estern E u ro p e ’s S 0 2 em issions - th e U n ited K ingdom , W est G erm an y , Italy, F ran ce, and Spain (T able 8.2) - but th e U K , Italy, and Spain refused to endorse the 30 p e r cent call and only W est G erm an y and F rance w ere club m em bers. H ow ever, o v er th e p receding y ear, several co u n tries had clearly begun to show much g re a te r aw areness o f the p roblem s o f acid rain, and g reater d eterm in atio n to act. T he U K argued th a t it w ould req u ire a m ore reaso n ab le tim e-scale, and it was not convinced th at reducing S 0 2 em issions was necessarily th e best cure for the acid dam age ailm ent (which m ight n o t even have been diagnosed correctly). T h e British sta te m e n t to th e C o n feren ce was unequivocal: ‘we see no point in m aking heroic efforts, at g re at cost, to control one out o f m any factors unless th ere is a reaso n ab le expectatio n th at such control w ould lead to a real im provem ent in th e e n v iro n m e n t’ and ‘B ritain ’s neighbours cannot expect h er to e n te r upon a crash program m e while th e re is still so much th at is speculative in th e a rg u m en t' (T h e Tim es, 26 Ju n e 1984. p. 6 ). T he U n ited States was a n o th er escap ee, arguing th a t not enough was yet know n ab o u t the likely effects o f a 30 p e r cent cut in em issions to em b ark on such a costly course o f action. B oth co u n tries stressed th a t they had m ade substantial progress in reducing air pollution since 1970, and insisted that this be recognized and ap p reciated overseas. B ritain and th e U n ited S tates em erg ed from th e M unich m eeting as ‘m arked m en’, w ith m ost o f th e ‘30 p er cent clu b ' m em bers insistent that these tw o m ajor polluting culprits should face up to th e ir in tern atio n al responsibilities and join the club. A s we shall see in th e next tw o c h ap te rs, they have m anaged to rem ain ‘fre e ’ (i.e. o u tside th e club) since th en by a com bination o f stu b b o rn n ess an d political inactivity.

Growing frustration F u rth er pressure was brought to b ear on those p arties to th e L R T A P C onvention w ho had not yet m ade a com m itm ent to red u ce th eir S 0 2 em issions w hen the C o n v en tio n 's E xecutive Body held its second m eeting in S eptem ber. A gain it m et with som e success, because tw o m ore co untries (Italy and C zechoslovakia) agreed to join th e ‘30 p er cent c lu b ’ (A c id N ew s, 1984, 5, p. 7). T he U K an d U S A w ere n o tab le in th eir persisten t lack o f w illingness to jo in . Scandinavian fru stratio n o v er B rita in ’s en tren ch ed attitu d e was clearly expressed when th e N orw egian Society for

International concern and initiatives C onservation o f N atu re a p p ealed directly to B ritain to accept th e 30 p er cent reduction in S 0 2 em issions, arguing th at ‘we can n o t afford to wait while B ritain delays m easures fo r cleaning; em issions’ (A c id N ew s, 1984, 4, p. 12). W hilst these efforts to ‘catch th e big fish’ w ere u n d er w ay, a ttem p ts w ere also in hand to tighten up th e p ollution control agreem en ts even fu rth er. T he Swedish M inistry o f A gricu ltu re was h an d ed a plan in O c to b er 1984 by the Swedish E nv iro n m en t P rotection B oard which aim ed at a 65 p e r cent reduction o f S 0 2 and a 30 p e r cent reduction o f N O x betw een 1980 and 1995 (A cid N ew s, 1984, 4, p. 10). T he fo rm er targ et w ould be reached by energy conservation, su lp h u r limits on fuels, and tight con tro l o f em issions from coal-fired furnaces; th e la tte r by g re a ter use o f unlead ed fuel and fitting o f catalytic co n v erters to vehicles, and use o f fluidized bed technology (see ch ap te r 7), low N O x b urn ers, and flue gas d enitrification in industry. Prom otion o f public in terest in and b e tte r u n d erstan d in g o f acid rain, and m obilization o f enviro n m en tal activists in publicity cam paigns, was also a hallm ark o f E u ro p e during the closing stages o f 1984. O v er 400 delegates from enviro n m en tal o rganizations in eleven W est E u ro p ean countries g ath ered for a w eekend conference o f forest d e a th at B regenz in the A ustrian A lps (A c id N ew s, 1984, 5, p. 3). T hey plan n ed various activities, including th e 1985 In tern atio n al A cid R ain W eek (15-21 A pril 1985) and d em o n stratio n s for W orld E n v iro n m en t D ay (5 Ju n e 1985). T he success o f such cam paigns to d ate was ev ident in th e results o f a 1984 survey in W est G erm an y w hich revealed th at 97 p e r cen t o f th e popu latio n had heard o f the co u n try ’s ‘dying fo rests’ (W aldsterben), m ore in fact than those w ho could nam e th e c o u n try ’s F ederal C hancellor o r P resident (M uller 1984: 2).

ENFORCEMENT AND PROGRESS (1985) W ith so m any im p o rtan t (and o ften successful) n atio n al and in tern atio n al initiatives taken during 1984, it was not surprising th at 1985 was to be a som ew hat q u ieter year on the acid rain front. It w as to be very much a year of considered reflection by politicians in E u ro p e an d N o rth A m erica, during w hich negotiatin g positions w ere re-ev alu ated and em erging scientific evidence carefully exam ined.

Low profile politics D iplom atic exchanges o v er acid rain contin u ed th ro u g h o u t 1985, but the issue was h andled in a m uch m ore ‘low p rofile’ m an n er th an in 1984. In early M arch, Swedish Prim e M inister O lo f Palm e d ep lo red B ritain ’s refusal to join the '30 p e r cent clu b ’, and urged all N ordic co u n tries to increase political pressure on B ritain to act against acid rain (T h e T im es, 5 M arch 1985).

182 Acid Rain C onciliation and gentle persuasion d o m in ated m ost in tern atio n al d ia ­ logue on acid rain. In m id -Jan u ary , for exam p le, W est G e rm a n y ’s C hancellor H elm u t K ohl, also com m enting on B rita in ’s contin u ed refusal to join th e ‘30 p e r cen t clu b ’, suggested th a t ‘we m ust discuss th e situation w ith each o th e r, as it is com pletely d ifferent in various cou n tries. Y ou [i.e. B ritain] have hardly any dying forests o r none at all. W e have areas - m ost B ritish people at least have h eard o f th e Black F o rest - w here we face a com plete cata stro p h e , and we m ust find a sensible m iddle line betw een ecology and econom y. B ut th e d eath o f the w oods is, o f co u rse, a special thing for us’ ( The Tim es, 18 Jan u ary 1985, p. 7). T h e E C E E xecutive B ody, heavily criticized for its lack o f success in its first tw o m eetings and largely eclipsed as a po w er-house for exciting innovations by the 1984 O ttaw a and M unich m eetings, held its third m eeting in H elsinki, F inland, in July 1985 (T h e Tim es, 10 July 1985, p. 8). R ep resen tativ es o f thirty co untries a tte n d e d . E n v iro n m en tal m inisters o f tw enty-one o f them (including m ost co u n tries in W estern and E astern E u ro p e , along with C an ad a) signed th e so-called P rotocol on sulphur em issions. T he P rotocol was a legally binding d o cu m en t by which these cou n tries (the so-called ‘30 p e r cent c lu b ’ - T able 8.5) prom ised to reduce th eir em issions o r tran s-b o u n d ary fluxes o f S 0 2 by at least 30 p e r cen t as soon as possible, an d by 1993 at th e latest. In his o p en in g ad d ress, K laus S ahlgren (E xecutive S ecretary o f th e U N E C E ) stressed th at ‘th e Protocol is not an end in itself, but rath er a m eans o f tu rn in g th e C onv en tio n into a reality ’ (A niansson 1985: 29). F o u rteen coun tries w ere eith e r unab le o r unw illing to sign th e P rotocol, but they did agree to sign a ‘declaratio n o f in te n t' expressing th eir will and intent to reduce th eir em issions, and th eir su p p o rt in principle o f the C onvention and th e e n d eav o u r o f th e Protocol signatories to achieve co ncrete results w ithin a fo reseeab le future. M ost o f th e fo u rteen (including Poland and Irelan d ) arg u ed that econom ic difficulties - they sim ply could not afford the costly p o llution control technologies at this tim e - prev en ted them from signing the Protocol straight aw ay. T w o - not surprisingly G rea t B ritain and the U n ited S tates - had a differen t d efence. T hey argued that th ere w ere still to o m any scientific u n certain ties, and m ore research was req u ired . B ritain also insisted that its S 0 2 em issions had fallen by 42 per cent betw een 1970 an d 1985, and by 25 p e r cent betw een 1980 and 1985, and th a t - even w ith o u t signing th e Protocol - an overall reduction o f 30 p e r cen t in S 0 2 and N O x em issions betw een 1980 an d the late 1990s seem ed highly likely (A niansson 1985:29).

NOx and vehicle exhausts By early 1985 scientists w ere startin g to switch th eir interest from S 0 2 tow ards N O x, w hen som e forest dam age studies suggested th a t N O x might play a m ore significant role than S 0 2 in producing so m e form s o f biological dam age. T his sw itch in scientific in terest was quickly accom panied by a

International concern and initiatives switch in the aren a o f th e political d e b a te , especially o ver suitable (and acceptable) control policies, because vehicle exhaust em issions produce m ost N O x (w hilst pow er statio n s and heavy industry - main targ ets o f the earlier cam paigning - p ro d u ce m ost S 0 2). Vehicle exhaust controls (using technologies o u tlin ed in ch ap te r 7) w ere introduced in a num b er o f co u n tries. S trong o v ertu res w ere being m ade in E u ro p e to adopt the tight US and Jap an ese em ission limits. A fter all, the argum ent w ent, U S N O x limits had d ro p p ed by 75 p er cent betw een 1971 and 1983 (A c id N ew s, 1985, 3, pp. 10-11), em issions o f p o llu tan ts from road vehicles in Jap an fell by 90 p e r cent betw een 1978 and 1985, and to d ay ’s Japanese vehicles are o n e-th ird m ore efficient th an corresp o n d in g m odels in 1975 (A cid N ew s, 1985, 2, p. 3). D espite such positive signs, the E E C C ouncil of M inisters decided in M arch 1985 (A c id N ew s, 1985, 2, p. 2) n ot to ad o p t such tight lim its, but instead to allow co untries to ado p t varying m ethods to m eet a staggered series o f targ ets for vehicle em issions (applicable to large cars from 1988, m edium -sized cars from 1991, and all new cars after 1993). Such a cautious m ove found little su p p o rt am ong E u ro p e ’s env iro n m en ­ tal groups. F riends o f th e E arth (E n g lan d ) found it ‘to o little to o la te ', and favoured ad o p tio n o f th e U S o r Jap an ese stan d ard s, based on the introduction o f T oyoto-type technologies (using ‘lean b u rn ’ engines with oxidative and catalytic co n v erters at different a ir-fu e l m ixtures) (A cid N ew s, 1985, 2, p. 2). T he W est G erm an g roup B B U (B un d esv erb an d B urgerinitiativen U m w eltschutz) favoured v oluntary speed limits o f 100 kph on m otorw ays and 80 kph on o th e r m ain ro ad s (A c id N ew s, 1985, 2, p. 2). T he E u ro p ean E n v iro n m en tal B u reau d escribed th e stan d ard s as ‘to o len ien t’, and argued th a t they w ould not p ro d u ce ‘the eq uivalent effect of the US stan d ard s on th e E u ro p e a n en v iro n m e n t’, as in ten d ed (A cid N ew s, 1985, 4, pp. 6 -7 ). D ifferent m easures w ere ad o p ted in different co u n tries, to m eet th e E E C targets. T h e A u strian g o v ern m en t, for ex am p le, agreed th at lead-free p etrol should be a \a ila b le at all filling statio n s in A u stria from O cto b er 1985, and tl.at U S em issions stan d ard s should be applied w ithin th e country (A c id N ew s, 1985, 2, p. 4). Financial incentives w ould be used to encourage ad option o f th e a p p ro p riate technology - a rew ard o f 7,000 schillings to be given to th e o w n er o f any car th at m et th e req u ired stan d ard s on 1 O cto b e r 1991. L iechtenstein favoured a m ore varied program m e, including im posing sp eed limits (50 kph in b uilt-up areas, 80 kph outside) from 1 Jan u ary 1985, eq uipping cars w ith catalytic co n v erters (to be ex em pted from tax ), and im p ro v em en t o f public tra n sp o rt system s (A cid N ew s, 1985 , 2, p. 4). W est G erm an y a d o p ted a policy th a t insisted th a t, from 1989 o nw ard s, all new p etrol driven cars in th e country would have to conform to the US-83 re q u irem en ts (from 1988 fo r all cars with engines larger th an 2 litres) (A c id N ew s, 1985, 1, p. 6). It concluded th a t the best way o f achieving this w as to fit catalytic con v erters. Financial incentives to speed th e volu n tary ad o p tio n o f this new technology included

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184 Acid Rain free ro ad tax fo r th e first fo u r to ten years (d ep en din g on engine size) on cars th at had it fitted , and tax red u ctio n s on existing cars w ith it already fitted. In D ecem b er 1984, th e E E C en v iro n m en t m inisters had ag reed th at un lead ed p etrol should be generally available in all m em b er co u n tries from 1 O c to b e r 1989 (A c id N ew s, 1985, 1, p. 6). L ead -free p etrol was already available in W est G erm an y and S w itzerland in 1984; it becam e available in D e n m ark , Sw eden, B elgium , and L uxem bourg at th e beginning o f 1985 (A c id N ew s, 1985, 2, p. 4).

Activism, awareness, and concern Public actions designed to bring m ore public in terest in an d co n cern ab o u t acid rain m ade 1985 very much th e ‘y ear o f th e activist’. By th en , m any o f the environm ental o rganizations had a b e tte r sense o f aw areness o f w hat w ould interest th e m edia (T V , rad io , and press) and o f how to ca p tu re and sustain public interest. In the p ast, pollution had n o t been seen as a p articularly new sw orthy topic; b u t now th e public ap p e tite had been w hetted. T h e in terest was th e re - it simply had to be fed and n u rtu red . F ebruary saw th e first ro u n d o f public actions in W est G erm an y , w hen R W E - a large pow er com pany th a t g en erates 40 p e r cent o f the c o u n try 's electricity and pum ps o u t aro u n d 0.7 million to n n es o f S 0 2 each y ear in doing so - w as ‘b ro u g h t to tria l’ b efo re a m ock trib u n al in Essen (A c id N ew s, 1985, 2, p. 12). T h e com pany was incensed, th e m edia w ere in te re ste d , th e au th o rities w ere confused, and the public w ere am used! F u rth e r action was d o tte d thro u g h th e y ear, to keep acid rain at th e fo refro n t of public aw areness. In M arch, fo r ex am p le, fo u r large sm okestacks at th e Shell oil refinery in P ernis, n e a r R o tte rd a m , w ere occupied by ten activists from F oE H o llan d , who flew b a n n ers w ith ‘S top A cid R ain N ow ’ and ‘P rofit is so u r’ slogans from th e to p (A c id N ew s, 1985, 2, p. 12). T hey stayed aloft fo r several ho u rs before descending; n o n e was arrested . T h e cam paigning m om entum th a t th e e n v iro n m en tal g ro u p s had gained at B regenz the p receding S ep te m b e r was m ain tain ed at a m eeting o f tw enty-five rep resen tativ es from W est E u ro p e ’s leading en v iro n m en tal organizations, held in L o n d o n from 15 to 17 M arch 1985. A com m on cam paigning strategy was fo rm u lated at th e m eetin g , designed to focus efforts on the m ain issues and to stren g th en alliances with o th e r interest groups and w ith industries engaged in th e p ro d u ctio n and sale o f pollu tio n -ab atem en t technologies (A c id N ew s, 1985 , 2, p. 14). In m any ways this m arked th e ‘com ing o f ag e’ o f th e acid rain public cam paign; the p enny had finally d ro p p e d th a t an effective enviro n m en tal cam paign could only be fought with stro n g co-o rd in atio n o f efforts and w ith co -o p eratio n from o th e r in terested p arties. T h e m ain show piece fo r d em o n stratio n s an d activities was th e th ird In tern atio n al A cid R ain W eek (14-21 A p ril), o rganized again by IY F.

International concern and initiatives E vents o f m any kinds, involving th e public as well as activists, w ere held in F inland, Sw eden, N orw ay, D e n m a rk , W est G erm a n y , P o lan d , C zechoslo­ vak ia, th e N eth erlan d s, B elgium , Irela n d , E n g lan d , S cotland, W ales, F rance, A u stria, Italy, P o rtu g al, C an ad a, an d th e U n ited S tates (A d d N ew s, 1985 , 2, pp. 10—11). M ost events got good coverage in th e m edia and helped to bring th e m essage hom e to th e public. O ne particularly effective action was the releasing o f balloons at em ission sources in W ales, Scotland, W est G erm an y , A u stria, an d the U n ited S tates to sym bolize the spread of acidifying oxides from identifiable po in t sources. In L o n d o n and H olland fake parking tickets explaining the N O x p roblem w ere issued to perplex ed drivers in large n um bers (30,000 in L ondon alone). T h e cam paigning w heels w ere k ep t tu rn in g fu rth e r at th e In tern atio n al C itizens C on ference on A cid R ain, held in th e N eth erlan d s from 20 to 25 M ay and organized by F o E In tern atio n al. O v er seventy d elegates from tw enty-eight cou n tries atten d e d . It was truly in tern a tio n a l, because m ost W est E u ro p ean nations w ere rep re se n te d , along with P o lan d , H ungary, C an ad a, the U nited S tates, H ong K ong, th e Philippines, M alaysia, In donesia, B razil, A rg en tin a, and M exico { A d d N ew s, 1985, 3, pp. 1516). T h e m eeting agreed to th e creation o f an A ir P ollution A ction N etw ork, designed to p ro m o te exchange o f inform ation and stim ulate co-ordination o f action betw een d ifferen t co u n tries. B ut its m ain tangible p ro d u ct was th e decision to launch serious acid rain cam paigns in th e U n ited S tates and the U n ited K ingdom (the tw o largest c o n trib u to rs to acid rain am ongst w estern industrialized nations). E u ro p ean environm en tal activists w ere keen to tak e th e b attle on to British soil. A fter all, th e U K - th e largest e m itte r o f S 0 2 in W estern E u ro p e , which exports tw en ty -th ree tim es as m uch su lp h u r as it im ports and refused to join the ‘30 p er cen t c lu b ’ - was seen as the ‘dirty old m an o f E u ro p e ’ ( A d d N ew s, 1985, 3, p. 10). T he U K cam paign was to focus on th e co u n try ’s tourist industry (its second larg est), an d involved calling on all foreign visitors to boycott th e U K as a holiday d estin atio n until it agreed to reduce dram atically its S 0 2 em issions. C itizens th ro u g h o u t E u ro p e w ere invited to send 50,000 p re-p rin ted p ostcards (w ith th e caption ‘W e love your country . . . bu t not y o u r p o llu tio n ’) to U K hotels a.id tourist inform ation offices, to reg ister th e p oint ( A d d N ew s, 1985, 4, p. 16).

CONCLUSIONS Since the m id-1970s, acid rain has been p ro je c te d to the fo refro n t of in tern atio n al political d e b a te in the w est. D am age believed to be caused by acid rain has been discovered in m ore and m ore countries. Public interest in the issue has been sp ark ed off by press coverage and by publicity events by activists. T his in terest reflects a grow ing public concern for the environm ent: a recen t O E C D o pinion poll found that 62 p e r cent of A m ericans and 59 p er cent o f E u ro p ean s rated enviro n m en tal p rotection

186 Acid Rain higher than econom ic grow th ( The T im es, 13 S ep tem b e r 1985). T h ese two forces have been im p o rtan t catalysts in en couraging m ore and m ore governm ents to realize the significance o f th e problem and to face up to th eir ow n responsibilities to act for th e collective b enefit. T h e recent history o f national and in tern atio n al in terest in acid rain reveals som e m ajo r areas o f ag reem en t and som e equally m ajo r areas of disag reem ent. Few w ould disagree with the verdict th at acid rain is o n e of the g reatest enviro n m en tal p roblem s o f o u r tim e, o r with the ob serv atio n th at acidification (how ever caused) has created p ro b lem s for lakes and rivers, forests, an d stru ctu res in m any countries. N eith er is th ere any d o u b t now th at u p p er air wind system s blow oxides and p o llu tan ts vast d istances, across national b o u n d aries and even wide o ceans. T h ere is a sm aller m easure o f a g reem en t o v er what has caused th e acidification, and even less ov er the m ost ap p ro p ria te m easures for solving th e problem . T h e lack o f unanim ity in national views on acid rain has not been for w ant o f trying. Since th e mid-1970s scientific and political m eetings on the subject have been held in m any co u n tries; th e scientific com m unity in particu lar has dev o ted much research to the key ingredients in th e 'acid rain p ro b lem ' - from em ission, th ro u g h d isp ersio n , to d ep o sitio n ; exam ining biological changes in fresh w ater, fo rest, and agricultural ecosystem s (see P art II); devising and testing various control technologies for reducing S 0 2 and NO* em issions at source (see P art III). T h e scientific literatu re on differen t acid rain th em es is now im m ense. T h ere is no escaping th e fact th at som e scientific q u estio n s are as yet far from fully answ ered. F o r exam ple, by late 1985 it had becom e ap p aren t that sulphur m ight be less im p o rtan t as a cause o f som e forest dam age than nitrogen oxides (the tru e significance o f hyd rocarb o n s was also u n d er question by th en ). If th a t conclusion turns out - with th e passage o f tim e to be tru e , then efforts to reduce biological dam age should be d irected m ore tow ards reducing vehicle ex h au st em issions o f NO* th an pow er station and industrial em issions o f S 0 2 (hence the in terest in ex h au st controls during 1985). T he key area o f u n certain ty rem ains linearity o f th e association betw een oxide em issions and acid deposition (w et and dry). If the association was linear, a given p ercen tag e reduction in oxide em issions w ould p ro d u ce a prop o rtio n al decrease in acid d ep o sitio n , a n d politicians could take com fort from th e fact that heavy investm ent in pollution con tro l w ould be likely to produce tangible im provem ents in air q uality (i.e. red u ctio n s in air pollution). B ut scientists have yet to establish th at it is linear. W hilst this uncertainty rem ains, it is all too easy fo r politicians to refuse to accept rigid targ ets for em ission red u ctio n s (like th e 30 p e r cent d ro p in S 0 2 em issions called for by ratifiers o f the E C E L R T A P C onven tio n). T h ere is uncertain ty o ver a n o th e r ‘linearity’, to o ; th at is the linearity o f the association betw een acid deposition and biological dam age. Put sim ply, if th at association is n o t linear (and th e re is no unequivocal evidence th at it is), then a given reduction in rates o f deposition m ay bring little real

International concern and initiatives reduction o f dam age in acidified lakes o r forests. U n certain ty o ver these two ‘linearities’ fu rth e r com plicates an already com plicated d eb ate. W e have seen how m any co u n tries now accept that S 0 2 em issions from pow er statio n s play a significant p art in producing acid rain , and how strong recom m endation s fo r firm em issions red u ctio n s w ithin specified tim e-periods have com e from Scandinavia and W est G erm any. T he sudden ab o u t-tu rn in W est G erm an views - previously strongly against costly pollution control but now leading the cam paign in favour o f it - once serious forest dam age had been established w ithin th at co u n try , offers a salutory rem in d er o f th e pow er o f self-interest in in tern atio n al politics (environm ental o r otherw ise). H ow ever, not all co u n tries ag ree. M any o f the E astern E u ro p ean countries, som e o f them very heavy pro d u cers o f S 0 2, have failed to accept the need for em ission controls - som e (like P oland) because they simply cannot afford it at p rese n t, but o th ers because they do not see it as a high priority area of investm ent o r ea st-w e st co -o p eratio n. T he U SSR has added an interesting twist to th e norm al su p er-p o w er ‘cat an d m ouse g am e’ by joining the so-called ‘30 p e r cen t c lu b ', leaving the U n ited S tates (w ho still refuses to jo in ) looking intransigent and unco o p erativ e in this aren a of international politics. T he U n ited K ingdom and th e U nited S tates - tw o o f the largest pro d u cers o f air pollution - have largely resisted intern atio n al scientific, diplom atic, and political en co u rag em en t to cut th eir em issions o f S 0 2 and NO*. T h e m ain platform o f th eir defence is that present scientific u nderstanding o f acid rain is still too lim ited, and much m ore research is required before they could em bark on costly pollution control program m es. A cid rain provides a fascinating illustration o f in tern atio n al politics at w ork. All the usual ingredients are th e re - hidden ag en d as, vested interests, frustration and elatio n , inspired initiatives, and raging rhetoric. M oney and m orality, as ev er, are key forces in th e political d eb ate. M oney is inevitably im p o rta n t, because pollution control on the scale favoured by som e cou n tries req u ires vast investm ent in control tech n o lo ­ gies and the m oney has to be found from som ew here. M any politicians have eagerly argued th at we can n o t afford such costly clean-up p ro g ram ­ m es, eith e r because the m oney sim ply isn’t th ere o r - m ore realistically because it is ear-m ark ed for m ore high priority uses (like defence and investm ent in nuclear pow er stations). H ow ever, the real q uestion is not w h eth er o r not society can afford to d evelop em ission contro l system s, but w h eth er o r not we can afford not to control emissions! T h ere are tw o issues intertw ined. First, the biological defence. It is questionab le w h eth er m any fresh w ater an d forest ecosystem s - on which we rely for resources and thus survival - can continue to function if acid deposition contin u es at to d ay ’s levels (i.e. if em issions are not controlled). S econd, th e econom ic defence. A lthough acid rain is a m ulti-m illion d ollar p ro b lem , savings against reduced rep air costs and so on w ould be offset against costs. T he problem s o f draw ing realistic com parisons betw een costs (easier to quantify) an d b enefits (m ore

187

188 Acid Rain difficult) are w idely recognized, but a 1981 O E C D survey concluded th at benefits w ould outw eigh costs. M orality creeps into th e d eb ate at all levels. Som e co u n tries clearly have m ore than self-interest at h e art, and they are p rep ared to m ake som e sacrifices for th e collective benefit - i.e. they will accept th e cost of pollution control within th eir cou n try because it will help to keep the environm ent at large (theirs an d o th e rs’) clean and biologically stable. O th ers place altruism low on th eir list o f p riorities. O verlying this m oral fo u n d atio n is in tern atio n al law, recognized by all civilized states. T he legal maxim sic utere tuo ut alienum non laedeas ('use your p ro p erty so as not to in jure your n eighbours’) is a general principle of international law (Johnson 1976). W hilst th ere is no g en eral pro h ib itio n to p o llu te, states cannot simply do as they please. T h eir actions sho u ld observe th ree duties (C o u rag e 1983): due diligence (‘they are obliged to observe all care so as to prevent th e pollution o f areas beyond th eir jurisdiction, and to co m b at it w hen it occurs’), g o o d neighbourliness (‘according to which every state is fo rb id d en to allow its territo ry to be used in a way prejudicial to th e rights o f o th e r sta te s'), and solidarity (u n d er which ‘states are obliged to tak e the interests o f o th e r states into account w hen engaging in o r allow ing em issions th at p revent the use o f air for o th e r p u rp o ses'). T h e ‘bottom lin e’ is self-interest. Q u ite sim ply, th e co u n tries th a t would b enefit m ost from red u ced p ollution are n o t the ones th a t w ould have to b e a r the highest costs. T he tw o co u n tries th at have swum m ost aggressively against the tide o f in tern atio n al opinion a re the U nited S tates and the U n ited K ingdom . It is fitting th at they are each exam ined in som e detail in the last tw o chapters.

9 ACID RAIN IN THE UNITED STATES Gripes of wrath. . .

O u r scientific com m unity is still u nclear as to . . . w hat control m ethods should be used. In o u r o p in io n , we ju st d o n 't know enough yet to im pose control m easures at g reat cost to th e A m erican peo p le with questionable results. (A . A lan H ill, q u o ted in La B astille, 1981:676) It is clear from w hat we have seen in th e last ch a p te r th a t th e U n ited S tates shares cen tre stage w ith th e U n ited K ingdom in th e a ren a of intern atio n al political d eb ate ov er acid rain. F our factors won the U S this pro m in en t - if totally unw anted - position in the d e b a te , and ta k e n to g e th e r they highlight the seriousness o f th e p roblem on th a t side o f th e A tlantic. O ne is the sim ple and largely un co n tested fact th a t th e U nited S tates em its vast am ounts o f S 0 2 (aro u n d o n e -q u a rte r o f th e w orld total - see T ab le 8.2), so it has a pre-em inent position in th e league o f 'b a d guys'. A second factor is th e large am o u n t o f dam age from acidification (how ever caused) now ev ident in N o rth A m erica. Signs o f serious dam age to lakes and forests sta rted to em erge in the E astern U n ited .States and in eastern C an ad a in the mid-1970s. Since th en , dam age has been rep o rted from an ever-grow ing a re a , even extending o v er to th e M idw est an d the Southw est U n ited States. F actor th ree is the tw o-dim ensional n atu re o f the N orth A m erican acid rain d eb ate , with m ajo r conflicts on th e east/w est and th e n o rth /so u th axes. T he first reflects th e grow ing fru stratio n o f states in th e N o rth east U nited S tates th at receive large q u an tities of acid d e p o sitio n , which they argue com es from large industrial a reas fu rth e r to th e w est. T h e o th e r dim ension stem s from the strong C an ad ian disen ch an tm en t at im porting acid rain from across the b o rd e r in th e N o rth east U n ited States. T he fo u rth , and dou b tless th e m ost im p o rtan t, factor is th e continued reluctance o f the US gov ern m en t to com m it itself to an in ternationally acceptable reduction in oxide em issions within an agreed tim e-scale. A lan H ill, q u o ted above, was speaking as C h airm an of the P re sid e n t’s C om m ittee on E nviron m en tal Q u ality , and he voiced th e opinion that m any U S politicians have held through the en tire d eb a te . T he U S rem ains (in late 1987) stubborn ly o utside the ‘30 p e r cent club' (T able 8.5), even

190 Acid Rain after the U K - its ‘p a rtn e r in crim e' - reluctantly conceded in S ep tem b er 1986 to a 14 p er cent cut in S 0 2 em issions by 1996 (see ch a p te r 10).

ROOTS AND ROUTES A ir pollution has long posed serious p roblem s in N orth A m erican cities. T he A m erican p eople have grow n accustom ed to New Y o rk ’s grim y and polluted air, thick photo-chem ical sm ogs in Los A ngeles, and heavy palls o f sm oke and grey skies o v er m ajo r industrial cen tres. O v er the post-w ar era the US governm ent has laun ch ed m any m ajo r initiatives designed to curb air pollution and clean th e n atio n 's skies - th e annals are littered with legislation to control pollution from industry, pow er statio n s, vehicles, and o th e r sources. M any o f these have been rem ark ab ly successful, and m any m a jo r cities now boast m ore sunshine, low er health bills, clea n er buildings, and generally im proved conditions since pollution control began. A m ajo r catalyst for recent change was th e N ational E n v iro n m en tal Policy A ct (N E P A ), passed by C ongress in 1969 u n d e r th e Nixon adm inistration (M arcus 1986:52). T he A ct declared a national policy designed (am ongst o th e r things) to 'en co u rag e . . . harm o n y b etw een m an and his enviro n m en t; [and] to p ro m o te efforts w hich will p rev en t o r elim inate dam age to the en v iro n m en t . . .’. T he E n v iro n m en tal P ro tectio n A gency (E P A ) was cre a ted to bring th e A ct to life. E n v iro n m en tal legislation bloom ed during the 1970s, fuelled by public p ressu re to co m bat declining enviro n m en tal q uality, inspired by N E P A , and stee re d by the E P A . Federal laws w ere passed on a wide range o f issues - from hu m an use o f n atu re, through pollution co n tro l, to protectio n o f en d an g ered plan t and anim al species (M arcus 1986:61). Especially relevant h ere was the replacem ent o f th e 1967 A ir Q uality A ct in 1970 w ith a C lean A ir Act (am en d ed in 1973, 1974, and 1977), which was designed to p ro tect and en h ance th e n atio n 's air q uality, set stan d a rd s for desig n ated p o llu tan ts, and establish visibility stan d ard s. M uch o f the early thinking was based on the notion o f dispersing p ollutants throu g h th e en v iro n m en t, in o rd e r to d ecrease co n cen tratio n s below levels th a t w ere found to be u n acceptable o r p ro d u ce serious local problem s. T his was the basis o f the 'tall stacks policies’ (d escrib ed in ch ap te r 1). intro d u ced in th e 1970 C lean A ir A ct. B ut scientists have since realized th at ‘w hat goes up m ust com e d o w n ’, even if it does so fu rth er afield (dow nw ind). W ith this has com e a realization th at long-distance tra n sp o rt o f S 0 2 and N O x in u p p er air w ind system s increases th e p rospect o f turning dry gases into acids (see Figure 2.7). T o a large e x te n t, th e re fo re , the legislation effectively co n v erted a local problem o f dry deposition into a m ore regional - and ultim ately tran s-fro n tier - problem o f w et deposition (acid rain).

Acid rain in the United States Dawn of awareness U p to the early 1970s, acid rain w as seen largely as a problem confined to Scandinavia. A t th e 1972 UN C o n ference in Stockholm (ch a p te r 8 ), A m erican delegates listened to Swedish rep o rts o f acidification dam age with detached academ ic in terest, and took little interest in th e th en quiet calls for p ro p er control o f long-range sulphur pollution. T h e new era daw ned on 14 Ju n e 1974, w hen a rep o rt ap p eared in the journal Science suggesting th at acid rain was falling on th e U n ited S tates (L ikens and B orm ann 1974). D rs G en e Likens and H e rb ert B orm ann respected biologists from C ornell and Yale U niversities respectively (see c h ap ter 1) - argued th at rain falling on p arts o f th e E astern US had increased in acidity to 100- 1.000 tim es norm al levels as a result of increased S 0 2 and N O v em issions, mainly from electricity and industrial p lants. Previously, they arg u ed , solid particles (i.e. so o t) w ould have neutralized these toxic em issions; this buffering capacity (see ch a p te r 3) d isappeared with the installation o f devices to elim inate these solid particles in sm okestacks. T h e Science re p o rt rang alarm bells and looked like a good story for the n ational m edia. T he N ew Y o rk Tim es (N Y T ), for exam p le, rep o rted (13 June 1975, p. 1) th at im p ro v em en ts in em ission control in cities had been offset by rapid industrialization o f rural areas (hence S 0 2 em issions had increased by ov er 45 p er cen t). It also o utlined th e b elief th at increased acidity o f rain was linked with reduced forest grow th in N ew E ngland and Sw eden, with increasing lake acidity in C an ad a, Sw eden, and th e U nited S tates, and w ith acceleration o f co rrosion dam age to m an-m ade structures. T his was the first shot in w hat was to becom e a p rolonged and at tim es acrim onious b attle to raise US aw areness o f and concern a b o u t acid rain. It was to be som e tim e before th e nation was to em b race th e acid rain issue with any sense o f urgency o r need ( N Y T , 4 July 1975, p. 10). But scientific in terest was by now aw ak en ed , and w ithin tw o years the th ree m ain scientific ingredien ts o f th e d e b a te had been established in th e US. O ne was the very presence o f acid rain; th e Science re p o rt was th e first o f a num ber th a t described high acidity in rain falling o v er the eastern side of the nation. T he second was firm evidence o f long-distance tra n sp o rt o f the culprit oxides, and this w as provided in plum e-tracking ex p erim en ts. A n early exam ple was a m an n ed balloon flight from St Louis (In d ian a) in Ju n e 1976, which show ed that pollu ted air (in this case derived from a Shell Oil refinery at A lto n , Illinois) can drift over 150 miles with little dilution ( N Y T , 23 Ju n e 1976, p. 27). T he third in g redient was reliable evidence o f acid dam age. E arly in 1977, surveys by a team from C ornell U niversity, led by D r C arl Schofield ( N Y T , 28 M arch 1977, p. 31; Schofield 1976), show ed that w ater in ov er half o f the high-level (o v er 2,000 ft) lakes in th e A dirondack M ountains in n o rth ern New Y ork S tate was th en acidic (see Figure 4.2c), and 90 p e r cent o f the lakes w ere devoid o f fish (see Figure 4.5c). Since then the A d iro n d ack lakes have yielded m uch evidence o f the

192 Acid Rain possible consequences o f fresh w ater acidification, an d they have figured large in th e public and political d e b ate in N o rth A m erica. By the mid-1970s it was clear that the quality o f the A m erican environm ent was in d ecline, even with the legislation th a t had em erged since 1969. A N ational W ildlife F ed eratio n (N W F) re p o rt, p ublished in Jan u ary 1976 (N Y T , 19 Jan u ary 1976, p. 13; 16 Ja n u ary 1976, p. 28; 14 F ebruary 1976, p. 24), n o ted th a t, although a ir pollution overall ap p eared to be on the decline, m any states had failed to m eet th e re q u irem en ts o f the federal air quality stan d ard s (laid dow n in th e 1970 C lean A ir A ct) by the mid-1975 deadline. It was also becom ing clear to a grow ing n u m b er of people th a t C ongress should, as a m a tte r o f som e urgency, am en d th e Act to p rev en t the serious d eterio ratio n o f clean air w here it th en survived - in national parks and w ilderness areas, and aro u n d national m onum ents. O ne tangible outcom e o f this b e tte r aw areness o f th e n eed fo r strong environm ental planning was th e em ergence o f public env iro n m en tal aw areness. T his was reflected in a massive grow th in m em bership o f environm ental groups (like F riends o f th e E a rth ). A n o pinion survey of conservationists, carried o u t by th e N ational W ildlife F ed eratio n early in 1977, found th at they listed air and w ater pollution as th e m ost urgent environm ental problem s o f th e day ( N Y T , 26 M arch 1977, p. 34). It was also reflected in th e em ergence o f en v iro n m en tal issues as key co m p o n en ts in the political electio n eerin g m achinery. Pollution was identified as a m ajo r area o f public concern th at should be ad d ressed by p residential aspirants in the 1976 elections ( N Y T , 28 M arch 1976, p. 14). O n 4 July 1975 - an ap t d ate - P resid en t F ord had o u tlin ed th e philosophy o f the g o vernm ent on which he w ould be seeking full-tim e re-electio n to the W hite H ouse in 1976 ( N Y T , 4 July 1975, p. 10). H e pledged total com m itm ent to co n tin u ed progress in cleaning up air and w ater, but also stressed th e need to cre a te new em ploym ent p rospects and pursue co n tin u ed econom ic progress. D espite th e glow ing rh eto ric, th e F o rd ad m in istratio n was to be a term o f hesitation and reluctance in bringing en v iro n m en tal reform s and legislation. It w as an e ra o f backsliding on environm ental reg u latio n . F or exam ple, less th an th re e w eeks a fter his 4 July speech, he an n o u n ced th e in tention to fu rth er delay (until 1982) th e in tro d u ctio n o f statu to ry em ission standard s on vehicles, originally in ten d ed fo r 1978 m odels ( N Y T , 25 July 1975, p. 9). N ew p roposals ap p ro v ed by th e S enate C o m m ittee on Public W orks in F eb ru ary 1976 ( N Y T , 7 F eb ru ary 1976, p. 24) req u ired th a t 10 p e r cent o f 1979 cars m eet th e highest em ission con tro l tests, and allow ed the o th e r 90 p e r cent to co n tin u e to m eet th e 1978 stan d a rd s up to 1980. In a m essage to C ongress in Ja n u ary 1977 ( N Y T , 8 Jan u ary 1977, p. 25), P resident F ord suggested am en d in g th e C lean A ir A ct to low er vehicle em ission stan d ard s, allow m ore use o f coal in p o w er p lan ts, and rem ove req u irem en ts prev en tin g significant d e te rio ratio n o f air quality in areas th a t already m et th e stan d ard s. A low ering o f ex p ectatio n s was also ap p a re n t w hen th e E P A ab an d o n ed its cam paign to im pose m an d ato ry tran sp o rtatio n -co n tro l plans on New Y ork City and o th e r big U S cities, as

Acid rain in the United States required by the C lean A ir A ct (N Y T , 14 Ja n u ary 1977, p. 3). It favoured instead a reliance on voluntary com pliance, because o f th e b elief th a t local opposition to m andatory schem es - by now stro n g - w ould only produce endless (and costly) litigation.

Calls for action By the mid-1970s calls w ere being m ade to a lter th e e arlier ‘tall stacks’ policies and to m ake m ore use o f th e em ission con tro l technologies then available. A n editorial in th e N ew Y o rk Tim es on 14 Ja n u ary 1976 (p. 12) called for g reater use o f scru b b ers (see ch a p te r 7) to achieve clean air stan d ard s, and n oted th a t o ver th e p receding tw o years the total n u m b er o f scrubb ers installed in th e U S had increased from 44 to 118. T his, it arg u ed , had m ade it possible for many users to use high-sulphur fuels without corres­ ponding increases in oxide em issions (beyond th e clean air stan d ard s). A featu re o f this tim e was th e grow ing chorus o f calls to am en d th e 1970 C lean A ir A ct, which by now was being widely violated and w hose im plem entation in all states an d cities was proving ra th e r difficult. C ongress considered a list o f p ro p o sed am en d m en ts to the A ct in 1976, but cost factors prev en ted them from adop tin g any ( N Y T , 9 Jan u ary 1977, p. 39). Industry was calling for relaxation o f som e o f th e m ore costly o r inhibiting clauses in th e original A ct. E arly in 1977 th e N ational A ssociation o f M anufactu rers recom m ended changes th a t w ould allow industrial pollution up to legal lim its in areas w here air was still cleaner than existing lim its, and fu rth e r changes to p erm it additional p ollution in areas w here national pollution limits had already been ex ceeded ( N Y T , 27 Jan u ary 1977, p. 45). T he A ssociation also called for rem oval o f the requirem ent that scrub bers be used to com bat industrial air po llu tio n , to allow polluters to select o th e r m eth od s (w hich m ight be m ore cost-effective for them and still produ ce th e sam e net im provem ent in air quality). W hen Jim m y C a rte r was elected to th e W hite H ouse in 1977, he pledged su pport for changing the 1970 C lean A ir A ct. By this tim e, to o , tensions w ere starting to a p p e a r betw een U S states over the inter-state tran sfer o f air pollution (and a tte n d a n t d am ag e). It had been know n for m any d ecad es th a t th e d o m in an t m ovem ent o f air m asses over the U n ited S tates was from west to east (F igure 9 .1 ), but th e im plications o f this for dispersal o f air pollution w ere becom ing painfully clear. T here w as, fo r exam ple, m ounting concern in New Y ork C ity and New Jersey state - w hich by th en had som e o f th e w orst pollu ted air in the U nited S tates - th a t they w ere becom ing victim s o f p ollution originating elsew here. A 1975 re p o rt from the Boyce T hom pson In stitu te ( N Y T , 13 O cto b er 1975, p. 33) blam ed m ost o f the air pollution in N o rth eastern states on sm okestacks in B irm ingham (A la b a m a ), Pittsburgh (P ennsyl­ vania), and G ary (In d ian a). F ears w ere also being voiced th at high acidity being found in rainfall sam ples from New Jersey m ight e n d an g er crops w ithin th e state ( N Y T , 31 A ugust 1976, p. 59) - with econom ic as well as biological consequences.

Figure 9.1

D o m in a n t p a tte rn s o f a ir flo w a c ro ss th e U n it e d S ta te s

Source: after V an C lccf (1908) Note: B ased on an analysis of 1160 low pressure ce n tres over the period 1896-1905

Acid rain in the United States H ow ever, this w as a p erio d o f serious national econom ic recession, and the cost im plications o f en v iro n m en tal p ro tectio n w ere being keenly d eb ated . E P A A d m in istra to r R ussell T rain estim ated in mid-1976 th a t it w ould cost oil-refining and electricity com panies o ver $30 billion o ver th e next ten years to com ply with existing pollution rules { N Y T , 6 Ju n e 1976, p. 51). T he US C om m erce D e p a rtm e n t estim ated th a t th e US business com m unity w ould have to spend $7.5 billion on new plan t and eq u ip m en t in 1977 alone to com bat pollution ( N Y T , 25 M ay 1977, p. 5). T h ere w ere som e d o u b ts ov er w h eth er th e ailing U S econom y could afford to shoulder such costs, an d som e calls to relax enviro n m en tal co ntrols - if only fo r a specified period - to h elp th e econom y. T h ere was also a stro n g and grow ing feeling th a t unless equally tight air quality standards w ere in tro d u ced in all state s, those with th e lowest stan d ard s w ould be at a com petitive advantage in a ttractin g new industries and keeping established o n es (w hich would not be obliged to meet the high costs of installing and o p era tin g effective em ission con tro l technologies). A gain the problem cen tred on N ew Jersey , w hich had m uch h igher stan ­ dards th an those set u n d e r the 1970 C lean A ir A ct (and 1973 am endm ents) by th e E P A and w idely a d o p ted in o th e r states ( N Y T , 11 Jan u ary 1976, p. 33; 16 January 1976, p. 63; 17 January 1976, p. 61). Early in 1976 studies were carried out in twelve areas within the state to determ ine w hether state stan d ard s could be low ered in an effo rt to keep food-processing and glass industries from leaving the sta te . O n e o ption considered was to allow the burning o f high-sulphur coal for g en eratin g electricity in th e south o f th e state. O n 12 F ebruary 1976 New Jersey G o v e rn o r B yrne stressed th e need for econom ic recovery - w here necessary above th e n eed for en v iro n ­ m ental im provem ent - in an nouncing the sta te ’s inten tio n to relax air pollution em ission stan d ard s fo r certain areas o f south Jersey to p erm it industries and pow er co m panies to burn fuels with a higher sulphur co n ten t, until sum m er 1977 ( N Y T , 12 F eb ru ary 1976, p. 65).

CARTER INITIATIVES T h e C a rte r adm inistratio n (1977-81) in h erited m any o f th e serious econom ic problem s th a t G erald F ord had w restled w ith, an d it had a sim ilarly m ixed success in dealing with en v iro n m en tal problem s. Rising energy costs during th e ‘energy crisis’ forced Jim m y C a rte r to form ulate an E nergy Plan during his first days o f office in 1977. T he plan involved - am ongst o th e r things - m aking m ore use o f the n a tio n ’s ab u n d an t coal supplies ( N Y T , 1 A pril 1977, p. 1; 23 M arch 1977, p. 4; 31 M ay 1977, p. 15). B ut th e adm in istratio n and its su p p o rters, as well as its critics, w ere w'ell aw are th a t one result o f reducing energy costs by using m ore dom estic coal and less im ported oil w ould be increasing em issions of SO? and N O x, thus increased air pollution. T h e plan recognized the need to d ep art from pristine clean air stan d ard s (th e sacrifice to be offered for th e prospect o f m ore and c h eap er en erg y ), and it included provision for

196 Acid Rain financial incentives to help pow er plants to install pollution-control equipm ent when they switched from oil o r natural gas to coal as a main fuel source. T he requirem ent that new coal-burning boilers be fitted with flue-gas scrubbers (F G D technology - see ch ap ter 7) was one of its most costly and controversial proposals. H ow ever, the plan caused concern am ongst US scientists. The N ational A cadem y of Sciences had earlier w arned that burning fossil fuels was having serious adverse effects on the w orld’s atm osphere, and the planneo increase in use of coal in the US was greeted with som e anxiety ( N Y T , 31 July 1977, p. iv). Scientists at the B rookhaven N ational L aboratories advised that the plan could shorten many p eople’s lives by up to fifteen years because of air pollution leading to chronic respiratory disease ( N Y T , 17 July 1977, p. 10). They forecast a toll of up to 35,000 p rem ature d eaths a year east of the Mississippi by the year 2010. T he C arter adm inistration also inherited its predecessor’s com m itm ent to econom ic recovery, w here necessary at the expense of environm ental quality. D ebate was heightened over w hether the federal governm ent should enforce strict pollution standards at the possible expense of industrial grow th. The adm inistration - faced with pro-relaxation lobbies on several fronts - supported com prehensive am endm ents of the 1970 C lean A ir A ct, particularly the m ovem ent away from com pliance with tight emission standards. The coal industry (via the N ational Coal A ssociation) was pressing for low ered air pollution standards to encourage electricity com panies to burn m ore coal ( N Y T , 20 A pril 1977, p. 18) - partly to support the Energy Plan but mainly to boost their profits. Vehicle emission standards were also high on the list of priorities for change. Vehicle m anufacturers - particularly F ord, C hrysler, and G eneral M otors - were keen to see standards relaxed, because otherw ise cars then being m ade would be in violation o f the 1970 schedule for reducing harm ful emissions ( N Y T , 10 F ebruary 1977, p. 19; 23 A pril 1977, p. 18; 30 July 1977, p. 8 ; 3 A ugust 1977, p. 11). The car industry had a pow erful bargaining position in arguing that unless controversial am endm ents to the 1970 A ct w ere agreed upon, they would not be able to begin legal production o f the 1978 model cars so they would quite literally have to shut down the industry and lay off vast num bers o f w orkers. T heir strong hand won the day, because it was agreed to include in the Bill a tw o-year extension of existing tailpipe exhaust standards for th ree key pollutants ( N Y T , 4 A ugust 1977, p. 1). T he H ouse of R epresentatives, in a lengthy deb ate, considered many proposed changes to the 1970 Act and on 27 May 1977 it passed a Bill (326-49) formally am ending it ( N Y T , 27 May 1977, p. 1). T h at Bill was passed by Senate on 5 A ugust ( N Y T , 5 A ugust 1977, p. 7) and signed by the President four days later. The Bill revised clean-up rules for nearly all sources o f air pollution, and gave cities with dirty air up to ten fu rth er years to m eet som e standards, while offering new protection to som e areas with clean air ( N Y T , 5 A ugust 1977, p. 9). It contained clauses to delay and

Acid rain in the United States w eaken control on vehicle exhaust fum es that co nstitu ted poten tial health hazards. It also had clauses th at w eakened existing rules th a t b arred activity resulting in d eterio ratio n in pristine a ir in national p ark s, national forests, and o th e r p ro tected areas. By S ep tem b er 1979, how ever, the In terio r D ep artm en t was to propose th a t forty-seven prim itive areas and national m onum ents aro u n d the country should be covered by the 1977 C lean A ir A ct, to protect them from uncon tro lled air pollution ( N Y T , 8 S eptem ber 1979, p. 10).

Economy or environment? By late 1977 politicians in the U S w ere well aw are o f th e p recarious links betw een environm ental policies and econom ic recovery. O n the one h an d , econom ic grow th would both req u ire and p ro m o te increased energy p roduction, and this w ould increase air pollution. T he E nergy R esearch and D evelopm ent A dm in istratio n concluded in S ep tem b er that US air pollution w ould get w orse o ver the next tw enty years because o f increased energy p ro d u ctio n , not (as critics had arg u ed ) because o f increased use of coal (as proposed in C a rte r's energy pro g ram m e) ( N Y T , 29 S ep tem b er 1977, p. 13). In tu rn , air pollution w ould cause much d am ag e, hence have high costs. T h e M idw est R esearch Institute estim ated , also in S ep tem b er, that air pollution was costing residents in large US cities at least $6 billion each year in dam age in p ro p erty an d health ( N Y T , 4 S ep tem b er 1977, p. 22). D am age in New Y ork C ity was highest at aro u n d $1 billion in 1970. The reverse side o f th e coin was th a t vast sum s w ould have to be sp en t on pollution-control eq u ip m en t, which w ould raise prices and reduce com peti­ tive abilities in som e in d u stries, especially those with large energy requirem ents. It m ight, in serious cases, lead to plant closure and unem ploym ent. A lready th e U S steel industry was facing serious difficul­ ties w hen faced with the need to spend h u n d red s o f m illions o f dollars on such equipm ent ( N Y T , 5 S ep tem b er 1977, p. 16). W hen 250 steelw orkers w ho had been laid off w ork d em o n stra te d outside th e W hite H ouse in S ep tem b er 1977 ( N Y T , 24 S ep tem b er 1977, p .27), the President n o ted that foreign industry (particularly in Ja p a n and W est G erm an y ) had sim ilar pollution-control co n strain ts, and th e ro o t problem was linked to the depressed w orld econom y ( N Y T , 30 S ep tem b er 1977. p. 19). T h e com prom ising attitu d e o f the ad m in istratio n to en vironm ental m atters w hen faced with econom ic problem s cam e to a head in F ebruary 1979, w hen the W hite H ouse w as charged with intervening in th e norm al regulatory process by frustrating E P A efforts to carry out the n a tio n ’s anti-pollution laws ( N Y T , 27 F eb ru ary 1979, p. 7). T he P resident was quick to point o u t th a t he had no intention o f underm ining these law's through his policies to fight inflation and reduce th e b urden o f federal regulation ( N Y T , 28 F eb ru ary 1979, p. 15). Six m onths later he pledged to C ongress that efforts to end th e energy crisis w ould not affect his a d m in istratio n ’s com m itm ent to clean air ( N Y T , 3 A ugust 1979, p. 24).

198 Acid Rain Acid rain drops By early 1978 the focus o f the US air p ollution d e b a te w as to sw itch, w hen concern rose ov er acid rain. G ra n te d th a t th e go v ern m en t w as tak in g air pollution seriously - o n e-th ird o f the $40.6 billion spent on th e e n v iro n ­ m ent in 1977 w ent to reduce air pollution ( N Y T . 1 M arch 1978, p. 14) progress in com bating th e problem was being seen as to o little, to o late, and too slow. A larm rose fu rth e r w hen surveys o f fishless acid lakes in the A d iro n d ack M ountains, first published in A pril 1978 ( N Y T . 29 A pril 1978, p. 25), indicated the likelihood th at the dam age was caused by co n tam in ated rain and snow originating in coal- and oil-fired pow er statio n s and industrial plan t in the O h io V alley and across the b o rd e r in e astern C an ad a. Scientific interest in acidification w as by now well ad vanced; research was even u n d er way to d evelop tro u t th a t could survive in th e A d iro n d ac k s’ acid lakes ( N Y T . 12 S ep tem b er 1978, p. 12). Political interest was also on the increase. In A ugust 1979 New Y ork state E nvironm en tal C onservation C om m issioner R o b e rt Flacke expressed concern ov er fish and w ater quality in 400 o f the A d iro n d ack 's m ajo r lakes ( N Y T , 18 A ugust 1979, p. 23). In th e sam e m onth th e C a rte r a d m in istra­ tion launched a ten -y ear pro g ram m e o f research (m an ag ed by th e A cid Rain C o-ordinatio n C o m m ittee) into acid rain and its possible effects ( N Y T , 12 A ugust 1979, p. 8 ). Scientists, env iro n m en talists, and som e politicians looked tow ards the E P A to tak e a lead in 'so rtin g out th e m ess' o f acid rain in th e U n ited States. It duly obliged in S ep tem b er 1978 ( N Y T , 12 S ep tem b er 1978, p. 12) by calling on electricity utilities to install scrubbers (at a cost o f aro u n d $10 billion) to filter o u t S 0 2 flue gases, the o u tp u t o f which had increased a lot w ith the planned massive shift to coal burning. T he N ational C om m ission on A ir Q uality re p o rted a year later th a t acid rain was getting w orse and m ore w idespread in the U n ited S tates ( N Y T , 1 O cto b er 1979, p. 61). M ost w itnesses po in ted th e finger at coal b urning in industry an d vehicle exhaust em issions.

Politics, economics, and acid rain T h e scene was now set for a p rolonged d eb ate on acid rain in th e U n ited States. Som e o f the critical early m oves w ere m ade in New Y ork sta te , w here ov er 7,000 acres o f pristine h abitats in th e A d iro n d ack s had already been seriously affected by acidification. In late Jan u ary 1980, G o v e rn o r C arey an n ounced th a t a g ro u p o f N o rth east states w ere seeking federal action against acid rain blow ing in from th e south and west ( N Y T , 28 Jan u ary 1980, p. 2). D ays la te r, th e s ta te ’s E n v iro n m en tal C onservation C om m is­ sioner R o b ert Flacke telegram m ed th e E P A to urge im m ediate action. He proposed tight federal em ission stan d ard s for S Q 2 and N O x, and

Acid rain in th