4th Session of the IPCC

8/3/2019 4th Session of the IPCC

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WMO UNEP

WORLD CLIM ATE PR OG RAMME PU BLICAT IO NS SER IES

WMO/UNEP INTERGOVERNMENTAL PANELON CLIMATE CHANGE

REPORT OF THE FOURTH SESSION

OF THE WMO/UNEP INTERGOVERNMENTAL PANEL

·ON CLIMATE CHANGE (IPCC)

Sundsvall, Sweden, 27-30 August 1990

IPCC ·6

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REPORT OF THE FOURTH SESSION OF THE WMO/UNEPINTERGOVERNMENTAL PANEL ON CLIMATE CHANGE

TABLE OF CONTENTS


1 • Opening of the sess1on................................ 1

1.1 statement by Mr. Ingvar Carlsson,the Prime Minister of Sweden 1

1.2 Opening statement by Prof. G.O.P.Obasithe Secretary-General of WMO 3

1.3 Opening Remarks by Dr. M.K. TaIba,the Executive Director of UNEP 6

1.4 Opening Remarks by Prof. B. Bolin,the Chairman of the IPCC 9

1.5 Agenda and programme of work of the session 12

2. Report of the Pre-Plenary Orientation Sessionof the Special Committee, convened as anopen-ended group (Sundsvall, 24-25 August 1990) 13

3. IPCC First Assessment Report 14

4. Date and venue of the next session of the Panel 14

5. Closing of the seSS1on 14

Overview to the IPCC First Assessment Report ..•....... 15

Annex A List of Participants



reason to be impressed with theskill with which you have oonderis edinherent and unavoidable complexitiesinto conclusions accessible to usall. We are also impressed withthe work of the experts on possiblestrategies for the years ahead.

REPORT OF THE FOURTH SESSION OF THE WMO/UNEPINTERGOVERNMENTAL PANEL ON CLIMATE CHANGE


1• OPENING OF THE SESSION

The fourth plenary session ofthe WMO/UNEP IntergovernmentalPanel on Climate Change (IPCC) wasopened at 1000hrs on Monday, 27

August 1990 by Professor BertBolin, Chairman of the Panel, atthe Tonhallen Conference Centre,Sundsvall, Sweden.

The list of participants isgiven in Appendix A.

1.1 Statement by the Prime Ministerof Sweden. Mr. Ingvar Carlsson

Mr. Ingvar Carlsson welcomedthe participants to Sweden. Hesaid:

"Mr Executive Director, Mr.Secretary General, Mr. Chairman,Delegates, Ladies and Gentlemen,

It is a privilege for me toaddress the fourth session of theIntergovernmental Panel on ClimateChange.

Upon the initiative of theUnited Nations EnvironmentProgramme and the WorldMeteorological Organization, theworld's most eminent specialistsand experts on environment and

climate have been asked by theirrespective governments to addressa uniquely complex problem: doesman by his activities change thecomposition of the atmosphere andthe biosphere to the extent thateven the climate itself willchange? This is no small questionto answer. Your report is anexcellent one. I want to thank allcontributors. We laymen have every

I would like to share with youmy understanding of the issues youhave presented to us.

First, the estimates. Yourbest estimates are that the rateof climate change is now some0.3 °c per decade.The earth IS ecosystemhas never before been exposed tosuch a high rate of change.

Second, the equally clearlypresented uncertainties. Decadescould in fact pass before scientistscan claim to fully understand whethera change due to human activities

actually occurred or not.

Third, the inertia of the climate.Once knowledge is at hand, furtherchange is already unavoidable.

Fourth, the uncertain, perhapseven unpredictable but extremelyworrisome consequences of a possibleclimate change - in particular fordeveloping countries.

These four impressions aloneare sufficient to state the uniquechallenge you have presented to us.No generation of political leadershas ever been presented with a similartask.

You have also estimated thatgreenhouse gas emissions from, inparticular, fossil fuels will haveto be cut substantially. According

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to these estimates, reductions ofsome 60 per cent is necessary inorder to reduce the rate of climatechange to rates that the biospherecould conceivably cope with.

Poor use less fossil fuels than

rich. This holds for rich and poorpeople as well as rich and poornations. But poor in the thirdworld have a right to a decentliving.

Yet, there is cause for someoptimism. True, there have beensetbacks. True, there is stillpoverty. True, absolute numbershave not even fallen. But it isequally true that literacy isincreasing and health is improvingin most parts of the world. Thebattle against poverty is being wonin many areas of the world. Weknow that population, environment,natural resources and developmentare closely inter-related.Preventative and precautionaryaction is the only longer termremedy for the problems ofdevelopment and environment. Therecan be no common action againstclimate change without common

action against poverty, destitutionand, indeed, oppression andinjustice. Policies must recognizeglobal interdependence and jointresponsibilities. This was alsothe central conclusion of theBrundtland report. In my view,this underlines the necessity toadditional assistance from the richworld. The 0.7% goal should justbe a first step. The funding needsmust be based on a fair burdensharing.

Let me return to the developedworld.

The material you have presenteddemonstrates the crucial role ofthe industrialized countries.These countries are responsible forsome 75% of the total emission ofcarbon dioxide. You alsodemonstrate that the technological

-··

potential for reductions is large.

As expected, the differencesin the per capi ta emissions ofcarbon dioxide are large betweenindustrialized and non-industrializednations. But this is not the whole

picture. Differences are even largerwithin the group of Lndustrf.a.Lted.,countries. The difference between"the per capita emissions of, say;Japan and China is less than halfthe difference between the per capitaemissions of the US and Japan.

ISome countries in the OEeD

have more than twice the per capitaemissions than other DEeD countries -with no corresponding differencein living standard. Some countriesin eastern Europe have much higherper capita emissions than many WestEuropean countries - with a muchlower standard of living.

This illustrates theresponsibilitiesof the industrializedworld. Its emissions must be cut,and, judging from the differenceswithin the group of industrializedcountries, there seems to be ampleroom for improvement.

Every nation can take someaction now. Let me give only oneSwedish example on energy consumption:we have recently introduced acarbon tax, as part of a majorrestructuring of our taxationsystem. '!he gasolinepricehas increased

more than thirty per cent. Thishas turned an annual four per centincrease of gasolineuse into a projectedreduction for this year. But this,and other taxation measures, onlyaffects consumption in Sweden. Wecannot take unilateral action thatwould hurt those sectorsof our economythat are exposed to competitionfrom abroad.

Thus, concerted internationalaction in necessary. I would liketo highlight four points for thenext few years:

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a First, a global convention onclimate change should becompleted at the 1992 UNConference on Environment andDevelopment. A clearcommitment to first stabilizeand then reduce greenhouse gas

emission is necessary. TheLondon agreement on thereduction of CFCs was oneimportant step forward. Thenext steps will be taken duringautumn, when the negotiatingbody will start its work.

o Second, developing countriesmust be allowed an increasingshare of energy use. Thereis also the need for additionalaid to the poor countries. Theindustrialized nations mustbear the brunt of the burden,as a joint responsibility.

o Third, there is a need formassive expansion of researchand development in new energysources as well as energyefficiency. More efficientresource management of theenergy and transport sectorshould be promoted.

o Fourth, there is the need forinternational programs forthe future reduction ofgreenhouse gases. The OECDcountries have to take thelead in this work. I lookforward to joint programswithin the QECD group, withinthe ECE group and within theEuropean group of countries.There is for example the needfor reducing the European coaluse, particularly in CentralEurope, in order to reducepollution of acid substancesand heavy metals, but alsogreenhouse gases. Correspond-ing programs for other partsof the OECD area are necessary.

These four points should beseen as initial precautionary steps

for a more far reaching commi tment.Further steps have to be taken asknowledge and experience buildsup.

The Intergovernmental Panelon Climate Change should continue

to assess the scientific advancementof our understanding of the cLamat;e

and the impacts of climate ch~'11.ge.. , - "

You have raised the awarenessof the risks for climate change.What scientists have suspected formany years has now reached thep:>licymakersngovernmentsand businessin order for action to occur. What~ n::w have to do is to take preeautirnary

action. There is no way of turningback into ignorance.

I wish you luck with the comingfour days!

Thank you. II

1•2 Opening Remarks by Prof. G.0.p .Obasi. the Secretary Generalof the World MeteorologicalOrganization (WMO)

IIIt gives me great pleasure

to address you on this auspiciousoccasion the fourth PlenaryMeeting of the IntergovernmentalPanel on Climate Change. Auspiciousbecause at this session the Panelwill approve its report which willbe submitted to the United NationsGeneral Assembly. Prior to this,the report will be seen by theSecond World Climate Conferencewhich, I have no doubt, will reflectthe conclusions of the Panel in theMinisterial Declaration to be drawnup at that Conference. I might add,also, that the importance of thismeeting has been greatly enhancedby the reputation which the IPCChas built up in the short two yearsof its existence,not only in scientificcircles, but also in the politicalarena.

Let me first therefore takethis opportunity, through you, Mr.

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Prime Minister, to thank theGovernment of Sweden for hostingthis historic meeting and forproviding these excellentfacilities for our sessions.Sweden is, of course, one of theforemost proponents of

environmental protection. Itscons tant support to the work of theIPCC is therefore not perhapssurprising but I would like toconvey, on behalf of the WorldMeteorological Organization, ourgrateful thanks to the Governmentof Sweden for its pioneeringefforts to preserve our planet.

May I also thank youpersonally, Mr. Prime Minister, for

the penetrating and encouragingremarks you have just addressed tous and for honouring us with yourpresence on this occasion.

It was in June 1988 that theWorld Meteorological Organization'sExecutive Council first agreed toestablish an IntergovernmentalPanel on Climate Change. This wasconfirmed shortly thereafter by theUNEP Governing Council. The firstmeeting of the Panel was held in

Geneva, in November of 1988. Thesedevelopments were subsequentlyendorsed by the UN General Assemblyin its resolution on "Protectionof Global Climate for Present andFuture Generations of Mankind"passed in December of that sameyear.

It is useful to recall howshort is the history of the IPCC.I think it is fair to say that few

of us involved at the beginningbelieved that so much could beaccomplished in such a short time,or that the work of IPCC wouldassume such enormous importanceto governments, their leaders andthe people of the world.

The very difficult task setat the first meeting of IPCC, just21 months ago, is nearlyaccomplished. Reports on

scientific assessment of climatechange, on potential impacts ofclimate change, on formulation ofresponse strategies and on theparticipation of developing countrieshave been completed. They form asolid foundation for finalizing the

overview and conclusions of the Panelas a whole this week. I am surethat the overview and conclusion~emerging from this meeting, herein beautiful Sundsvall, will be soundand very influential.

This would not have hapgenedwithout outstanding leadership.We have all been fortunate to haveProf. Bolin, Dr. AI-Gain and Dr.Adejokun as leaders of the panel

as a whole, and Dr. Houghton, Prof.Izrael, Dr. Bernthal and Mr. Ripertas Chairmen of the three workinggroups and the Special Committee.Dr. Sundararaman and Mr. Tewungwaof the IPCC Secretariat have alsoworked very.hard towards this week.This leadership has been inspiringand effective. More than 1,000specialists from 70 countries haveparticipated in this great task inone way or another. I would liketo congratulate each one of you,

and thank you allan behalf of theUN system and of people everywhere.You have participated in the mostcomprehensive internationalintergovernmental assessment everundertaken of a serious environmentaland scientific problem and you havecompleted your work well, and onschedule.

I would add, also, that muchof the progress made and the many

achievements. of the Panel would nothave been possible without the strongsupport and advice of our respectedand able Executive Director of UNEP,Dr. TaIba. I very much enjoy workingwith him and I have personallybenefitted greatly from his wideexperience. I look forward tocontinuing working and collaboratingwith him on several aspects of theimportant issue of climate change.

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Despite the achievements thathave been made, I do have oneregret. The pace of the activityfor completing the IPCC FirstAssessment Report made it difficultfor experts from all interestednations to participate in all the

meetings. As it turned out, theWMO/UNEP joint IPCC Secretariat,with guidance from the SpecialCommittee, did their best, withinthe funding available to them, tofoster the active participation ofdeveloping countries. But I dorealize that furthering suchparticipation has to be one of themain goals and has to be achievedas we move into the future, whensteps towards international actionto address the issue of greenhousegases and climate change will betaken.

I believe that the nations ofthe world will not want to losesuch an effective body as the IPCC,even as more formal negotiationsof a Climate Convention areunderway or completed. At the WMOExecutive Council in June, and therecent Special Session of the UNEPGoverning Council in August, of

this year, it was agreed that acontinuing IPCC would be of greatvalue in conducting studies onpolicy options and riskassessments, and in, from time totime, undertaking assessments ofadvances in the science and impactsof climate change.

Not only has your achievementin producing this first assessmentbeen a magnificent one in the

limited time available, but theprocess has served to catalyze aworldwide understanding of probablythe most profound issue facinghumani ty. I do not say thislightly. The issue is profound intwo fundamental ways.

First, the environmentaldimension is truly global in scaleand inter-generational in time.It is clear from the IPCC working

group reports that economicacti vi ties in all countries arecontributing to major changes inthe chemistry of the whole atmosphereof our small planet. These changeswill in turn alter the climate andsea level in ways which will affect

all countries, mostly adversely,for many generations to come. ~everbefore has human interventiQ.~ innatural systems on such a ~orld-wide scale been achieved, documentedand projected. We are now face tofacewith deepmoral dilerrmasconcerningour responsibility for protectionof our Earthly home, and ourresponsibility to future generations.

'Ibesecond importantconsiderationof this issue is that its solutionwill require fundamental changesin the world Is economic order. OECDofficers have already stated that"the present patterns of economicdevelopment are not sustainable".The over-exploi tation of resources,especially fossil fuel and forestresources, has brought us to ourpresent crossroads. Recent economicpatterns have also been characterizedby huge financial transfers, thewrong way, from the poor to the rich,

as the poor countries struggle tocarry their crushing debt loads.To solve the problem of greenhousegas increases requires the industrializedcountries to change their over-consuming ways. It also requiresthat development in the lessindustrialized world goes forwardin a sustainable manner - and thiswill require a large flow of assistanceboth financial and technological,from North to South.

Are the countries of the worldready to meet these challengesimplicitin your report? We will soon see.After you have completed your workthis week, the report will go tothe Second World Climate Conferencein Genevafran 29 Oc:::tobero 7 November.The Ministerial part of thisConference will provide the firstopportunity for countries to fonnallyrespond to your report, especially

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the policy options. The scientificsessions will permit careful reviewof the science aspects of the IPCCreport as well as the 10-yearglobal scientific effort of theWorld Climate Programme.

As the executive head of ascientific and technical agency,I am particularly interested in therecommenda tions of IPCC on thefuture needs in research andmonitoring and in the outcome ofthe discussions in the Second WorldClimate Conference on the WorldClimate Programme. Further,improvements in model predictionsand determination of climatetrends, among others, are of

paramount importance to myOrganization.

Immediately following theSecond World Climate Conference,there will be consideration of yourreport and the Second World ClimateConference outcome at the 45thSession of the United NationsGeneral Assembly. This will giveall countries, including those whocould not actively participate inthe IPCC work, an opportunity to

express their views on how weshould collectively address thesubject.

Finally, in February 1991,national delegates will be invi tedto gather for the opening ofnegotiations on a FrameworkConvention on Climate Change inWashington, D.C. It is very muchto be hoped that such a Conventionwill be ready for signature by the

June 1992 UN Conf erence onEnvironment and Development inBrazil. WMO and UNEP are already,at the request of the UN GeneralAssembly, making preparations forthese formal negotiations.

In this context, I wouldpropose that this IPCC plenarysession decide on a mechanism forresponding quickly to the needs ofthe negotiators when they begin

their task on a convention and theassociated protocols.

In this year, 1990, we couldbe on the threshold of a new eramarked by respect for the environmentof planet Earth, and by environmental

and economic equity between nations.I hope that we may all continue towork together to make it so. .T

Thank you all."

1 .3 Opening Remarks by Dr. M.K.Tolba. the Executive Directorof the United Nations EnvironmentProgramme (UNEP)

"Mr Prime Minister, Prof. Obasi,SecretaryGeneral of wrvD , Mr Chainuan,Your Excellencies, DistinguishedDelegates, Ladies and Gentlemen.

It is an honour to join thisdistinguishedassembly, and to expressthe deep appreciation of the Uni tedNations Environment Programme toyou Mr Prime Minister, and throughyou to the Government and peopleof Sweden for hosting this criticalmeeting of the Intergovernmental

Panel on Climate Change. We meetto conclude the first phase of thePanel's work, and to adopt its eagerlyawaited report. UNEP comes too muchto you in Sweden, Mr. Prime Minister,in fact UNEP was born in Stockholm.Since then you never faltered inextending the required nurturingand support.

Let me also express my profoundgrati tude to my colleague and friend

Professor Obasi and his colleaguesat the W::lrldeteorologicalOrganisationfor the exemplary co-operation weare having together. A special wordof thanks goes to my friend ProfessorBert Bolin and members of his Bureauand to the Chairmen of the threeWorking Groups: Dr John Houghton,Prof. Yuri Izrael and Dr. FredBenthal - for their truly outstandingwork in preparing this FirstAssessment Report. Let me also

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thank my friend and colleague JeanRipert, Chairman of the SpecialCommittee on the Participation ofDeveloping Countries. A number ofcountries from the global Southhave participated in the IPCC.True, that number could and should

be higher. But your efforts havefaci1i tated the participation ofa number of developing countriesduring this first phase of the IPCCprocess.

Ladies and Gentlemen,

Efforts of the IPCC in the pasteighteen months have been amongstthe most daunting and intensivein the history of science.

Over one thousand leadingscientists pulled together fromdeveloping and developed countries,united in a single cause: tosharpen our understanding ofclimate change and global warming,and chart effective, equitableglobal responses. In spite ofuncertainties and lack of knowledgein a number of areas the verdictof your deliberations is clear: ourplanet is already committed to

global warming. It is now (and Iquote from Working Group I)"certain that emissions resultingfrom human activities aresubstantially increasing theconcentrations of greenhouse gasesand these increases will enhancethe greenhouse effect resulting onaverage in an additional warmingof the Earth's surface".

Scientific evidence indicateswe face warming trends faster thanat any time in 10,000 years. Ifhuman activity continues thisunsustainable strain on our livingbiosphere, average temperatures mayrise by about 0.3 degrees Celsiuseach decade, and by about 3° Cbefore the end of the twenty-firstcentury.

The current findings confirma sea-level rise of about 20 cm

1Icould happen over four decades; anda 65 cm rise by the end of the nextcen tury . Should that occur 1 coralislands and low-lying coastal areas- unless defended at great cost -face catastrophe. If only onepercent of the world's expected

population of six billion by theend of this decade are adverselyaffected by sea level rise indficedby global warming, there wi.ll be60 million more environmentalvictims{environmental refugees.

Your reports are soberinganalysesof other impacts, includ'ing thepossibility of sudden, abrupt changesin climatic patterns. Weather,pest and agricultural diseasepatterns may change. Forests face

the likelihood of increasedmortality. Biological diversitycould be further impoverished.Securing global food supplies forskyrocketing populations in poorand marginal lands, subject tounpredictable climatic regimes couldinvelve challengesunknown to humanity.In many cases, and I quote fromthe report of Working Group II,"the impacts will be felt mostseverely in regions already under

stress, mainly the developingcountries".

Mr Chairman,

The findings of this Panel arethe most authoritative to date, areal advance in scientific knowledgesince the time when experts - convenedby the WMO, UNEP and the InternationalCouncil of Scientific Unions - metin Villach several years ago. Inthe past decade, the WMO World ClimateProgramme has steadily built thecase for climate change. Now, yourreport leaves little doubt: the longeruncontrolled greenhouse gas emissionscontinue, the more difficult andcostlyinevitablecontroland adaptationmeasures will be. Stabilizationof atmospheric greenhouse gasconcentrations at present levelsdemand - in most cases - a minimuminunediatereduction of 60 % in global

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greenhouse gas emissions. That isnot the conclusion of ecologicalprophets of doom. These are thefindings of distinguishedscientists from allover the globe.

The facts before us are

horrifying, demanding we act now.While the Montreal Protocolamended in London two months back -has bought us time by ensuring thevirtual elimination of some of themost powerful and longlivedgreenhouse gases thechlorofluorocarbons we mustensure their replacements havelittle or no greenhouse potentialand we must go very much furtherin limi ting other greenhouse gasesand adapting to potential impacts

of climate change.

Ladies and Gentlemen,

No one expected the FirstReport of your Panel to answer allquestions and close all knowledgegaps. Significant unknownspersist. We need feedbacks forclimate modelling. We need toelaborate regional climaticpatterns. We need further

elaboration and costing ofnecessary actions.

The work of your Panel shouldremain the world's most reliableknowledge base scientific,economic, social, public policy -feeding into and responding to theneeds of the internationalnegotiations for a GlobalConvention on Climate Change. TheGeneral Assembly and governingbodies of the World MeteorologicalOrganisation and UNEP want suchnegotiations to commence now,immediately following the adoptionof your First Report. And yourWorking Group III points thedirection in this respect where itsays "the potentially seriousconsequences of climate change onthe global environment givesufficient reasons to begin by

adopting response strategies thatcan be justified immediately evenin the face of significantuncertainties".

~tirns 00 tbe Global O::nventioo

need to hammer out coordinated global

actions designed around specific_schedulesand targets to limitgreenhoosegas emissions in key sectors, suckas energy, industry, transportatioi,agriculture and forestry. We aretalking about changing the world'skey economic engines driven by fossilfuels, and changes in key sourcesof public income. Difficult as thatwill be, control strategies to savethe planet are beneficial in theirown right.Increasedenergyconservataonand efficiency would tackle known,

persistent environmental problems,including acid rain and chronic airpollution. But for action to occurthe on-going, expert input of theIPCC is crucial. That is why Irecommend _- and the GoverningCouncil of UNEP endorsed - thecontinuation of the work of the Panelas a joint Panel with WMO.

Mr Prime Minister, Mr Chairman,Ladies and Gentlemen,

No individual country can protectits patch of sky, or lower thelevel of greenhouse gases overhead.We need a truly global partnership,in \'him ilia gJchll &:uth isawrqriatelycompensated, financially assistedby resources additional to the currentflows, and ensured access to efficienttechnologies, to become real partnersin the required major global effort.Over and above, East and CentralEuropean oountriesmust alsobe assistedto join fully the global effort.

The London meeting of the Partiesto the Montreal Protocol has setthe tone on how to proceed, whatdifficulties are expected, whatcompromises are needed.

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I am fully aware it will bemuch more difficult to negotiatea meaningful climate convention,a convention with clout, not apaper tiger. I am also fully awarepeople everywhere will agree aplanetary hothouse can not be left

to our children.

Let us therefore leaveSundsvall committed to begin inthis decade - the last in thismillennium the difficult butunavoidable task of saving ourplanet. Let us leave Sundsvallcommitted to revising our attitudesand our actions, to opening oureyes to the damage we are causingto this fragile planet we don'town: the planet which actually

belongs to the beautiful childrenwe have just heard singing songsfor life. Our planet is theirs andtheir children IS. Let us thus leaveSundsvall committed to movingintergenerational responsibilityfrom a slogan to a belief, toaction. Let us leave Sundsvallcommitted to pulling together toensure the judgement of history oneveryone/on each of us/is not acondemnation, but a recognition

of a victory in the push towardsglobal partnership.

Thank you."

1.4 Qoeninq Remarks by Prof. B.Bolin, Chairman of theIntergovernmental Panel onClimate Change (IPCC)

"Mr Prime Minister, ProfessorObasi, Secretary-General of WMO,Dr Tolba, Executive Director ofUNEP, Delegates, Ladies andGentlemen,

The IPCC, has been working forabout one and a half year toproduce a first assessment of apossible future man-induced climatechange. Extensive reports from the

four working groups that wereformed by IPCC are available aswell as the Overview and Conclusionsand an Executive Summary that willbe the subject for discussions atthis fourth plenary meeting of thePanel. I wish to express my sincere

thanks to all those that -haveworkedso hard to achieve this. Time hasbeen short and in spite ofisomeshortcomings I expect that the ,reportcan serve as a knowledge base forsome years.

The purpose of this briefintervention is to focus ~n a fewaspects of the problem that Iconsiderimportant.

First of all it is likely that

the discussions about this subjectmight lead into analyses of a largenumber of details, which in themselvesare important, but that also mayconceal the broad and most likelyserious long-term problem that maybe confronting humankind. Let uskeep in mind I during these next fewdays that we indeed must view thisissue in a 50 year perspective.

Also there is a need to develop

further a solidarity betweennations. As a matter of fact I thinksuch a broad attitude to the problemis~ inorder far us to ultinatelyreach agreements on actions thatmay well have to be far-reachingand in the long run are going tobe costly.

We are, however, confronted witha dilerrmawhich is not easily resolved.The uncertainty of the predictionsabout future changes of climate andassociated impacts are considerableand it does not seem likely thatmuch more accurate predictionswill be available for quite some.

time. The question then being askedby some is: Is it really justifiedto prepare for actions already nowwith the aim to slow down the build

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up of greenhouse gases in the

atmosphere ~whynot wait until our

knowledge is more accurate?

Myanswer is: Weneed to reach

agreements on some action

programmes soon. The reasons are

found in the report. I wish on thisoccasion to spell out the reasons

that I consider most essential. The

task of IPCC is, however not to

draw up an action programme. This

will be a subject for negotiations.

But the work by the IPCC has

convinced me that it is urgent to

begin.

* Weknowfor sure that the

greenhouse gases are

increasing and, if specific

preventive actions are not

taken, that their collective

effect within about 40years

might be equivalent to about

a doubling of carbondioxide

in the atmosphere (over

its preindustrial

concentration).

* There will be a change of

climate, even though we

do not knowits magnitude

very well, nor howrapidlyit will comeabout. Also,

the uncertainty range given

implies that it is about

as likely that future changes

could be larger than the

most probable change that

has rem predicted as smller.

* The inertia of the climate

system delays and conceals

the climate changes that

well may be on the way,

but does not prevent them

fromoccurring. At anyone

time the observed change

is significantly less

than what the increase of

greenhouse gases already

emitted ultimately will

bring about.

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* Increased concentrations

of greenhouse gases that

may occur in the future

will return to preindustrial

levels only slowly, i.e.

00 the timescale of a century

or more, even if effectivelimitations of the emissions

were quickly agreed upon ?at that time. Changes of .~.

climate that maytake place

would be with us for a long

time.

* Admittedly, wedo not know

well howserious the impacts

of climatic changes could

be for the nations of the

world, since wecannot yet

and will probably not for

qui te some time be able to

predict their regional

distribution. It should

be recognized, however, that

S[:atial variability of re:: t i .ooalchanges of climate will be

significantly larger than

the spatial variabili ty of

the predicted global changes.

*

If no preventive measures

are taken beyond phasingout CFC-gases in accordance

with the revised protocol

for protection of the ozone-

layer, burning of fossil

fuels will be contributing

to tie i .n : : :m::Ise of tie ~effect by more than 60% of

the total in the beginning

of the next century.

* In the past it has taken

of the order of half a centuryto develop a primary energy

resource, e.g. oil, to becare

a major component of the

global energy supply system.

"!here are 00 reascns to l:::elieve

that the development of a

SlWly systemfar other energy

sources, e.g. renewable



sources, could be achievedmore quickly.

* Measures to reduce theemissions of greenhousegases tha.t w:uld be bereficial

for society in other regards

also are available and couldbe employed. We could inthisway buy time for furtherreseard1. arrl for intematia1alnegotiations with the aimto reach agreements on morefar-reaching preventivemeasures to the extentnecessary.

* It seems i.mpJrtanto explorewhat can be achieved wi thsuch an initially modest

approach, also in view ofthe need to understandbetterthe economic implicationsof a major programme forcombatting global climatechange.

Is it likely that such a morelimited action programme will beadequate in the long term? I doubtthat. But economists also point outthat a more far-reaching and

drastic programme could not besuccessfully implemented quicklyand might have major negativeimpacts on world economy.

The crucial question becomes:How much of a climate change isgoing to be acceptable, whateverwe may mean by the word acceptable?

Well, we do not know and itwill take time until we knowbetter.

It may well take another tenyears, even if a significant changeof climate is actually already onthe way. The stakes are high andsome insurance against thedevelopment towards an ever morerapid exploitation of our natural

resources would be most desirableand would represent a prudentstrategy. The later we get goingthe more difficult and costly willit be to take more stringentcounter-measures at a later time,if necessary.

Obvious measures to be agreedupon and implemented in the?nearfuture would be as follows:;

,.

* The agreement on phasingout the use of key CFC-gases should be implementedas soon as possible. It isimportant to make sure thatsubsti tutes do not havesignificantgreenh:use effects.

* Increase the efficiency bothin energy production andenergy use; this should bepursued with urgency andcould to a o:nsiderabledegreebe paid for by the energysavings that w:JUld be achieved

in this way.

* Improved forest managementcould o::ntrililteignificantlyin preventing further increase

of carbon dioxide in theatmosphere.

However, a climate change cannotbe stopped without substantialreductions of the use of fossilfuels.

In view of the very long leadtimes for the development of newenergy supply systems, it is urgentto find ways and means to establishsome long term policy for a sustainablesupply of energy for the world asa whole. Reliance on coal, oil andgas, might not only double but inthe long term perhaps even triplethe atmospheric carbon dioxideconcentrations. Breeder reactorsprobably would have to replace thetraditional reactors, if nuclear

11



energy should be a long termsolution. We do not today know muchabout their security nor the costfor such an energy supply system.A sustainable solution must,however, ultimately to asubstantial degree be based on the

use of solar energy in one way orthe other. Major financialresources are required now forresearch and development to providethe long term solutions that adecade or two from now might wellbe of crucial importance. It isremarkable that such research anddevelopment efforts at presentmerely have about 10% of theresources that are set aside fordeveloping nuclear energy.

Last but not least, most of theincreasing greenhouse gasconcentrations in the atmosphereare still due to the industrializedcountries of the world althoughthis situation is changing. It isnot surprising that developingcountries now wish to get accessto reasonably cheap energy fortheir development.

Is it not obvious that the

technologically advanced countriesdo have responsibility to aid inthe transfer of advanced andefficient techniques to thedeveloping countries in theirstriving for better livingcondi tions? It is even in theirown interests, since it couldbecome an effective measure forreducing the rate of increase ofgreenhouse gases in the atmosphereto the benefit of all nations.

I wish· finally to emphasize,that the IPCC ha~ been given thetask to assess our knowledge of thelikeliness and the characteristicsof a climatic change as well as itsimpacts and to provide informationon means to combat or mitigatesuch changes. The IPCC should,

however, not be a forum for politicalnegotiations. It is important thata scientific-technicalasisbe providedfor negotiationstowards internationalagreements on preventive actions.Such a basis should be establishedin close international cooperation,

since the process itself will helpin resolvingdifferencesanong nations..I am convinced that we will serve~our purpose best by giving as cleara description as possible of theissue.

It is of course, not possibleto avoid completely politicalconsiderations having an imprinton a report of the present kind.Simply the choice of matters to be

considered in the analysis willpartly be based on value judgementswhich may well differ from onecountry to another. It has been myaim to minimize the influences ofsuch considerationsas much as possiblein conducting the work of IPCC. Iwill welcome suggestions that wouldfurther improve the report in thisregard. It is also important thatfacts are provided as clearly aspossible not the least on issuesthat may be controversial. In this

way I hope that the report can serveas a basis for negotiations.

I am looking forward to workingwi th you during the coming fourdays. The report that will comeout of this meeting should hopefullybe a milestone in dealing with theissue of global climate change.

Thank you. II

1.5 Agenda and programme of workof the session

1 . 5 . 1 '!he Panel agreed (i) to discuss

and adopt the IPCC First AssessmentReport and (ii) as part of suchdiscussion, to consider the reportof the session of the Special Canmitteeon the Participation of Developing

12



-----

Countries, convened as an open-ended group (Sundsvall, 24-25August 1990).

1 .5.2 The Panel also agreed thatthe parts of the report of itsthird plenary session (Washington,

D.C., 5-7 February 1990) annexedas Appendices C and D be moved tothe body of the report.

1.5.3 The Panel further agreedthat, since the policymakerssummaries of the Working Groups andthe Special Committee had beenapproved by their respectiveplenaries, they would not besubject to amendment at thesession. Nonetheless, their

content could be discussed in thecourse of the consideration of theFirst Assessment Report.

1.5.4

arriveThe Panel also agreed toat its decisions by

consensus.

2. REPORT OF THE PRE-PLENARY

ORIENTATION SESSION OF THE

SPECIAL COMMITTEE, CONVENEDAS

AN OPEN-ENDED GROUP (SUNDSVALL,

24-25 AUGUST 1990)

2.1 The Chairman of the SpecialCommittee emphasized the followingpoints in his remarks to the panel:

i. It may be recalled that theSpecial Commi ttee did not formallyadopt its report during its thirdsession (Geneva, 31 May - 1 June1990); also the summary was draftedsubsequent to the third sessionby its Chairman. After discussion

and adoption of some amendments,the Committee formally adopted itsreport and summary. In the courseof this action, it decided torequest the Panel (a) to considerits report to be its policymakerssummary and (b) to consider itspreviously-called policymakerssummary as its executive summary

/

to form part of its policymakerssummary. The Special Committeerecognized that its newly-namedpolicymakers summary could not beconsidered in isolation; itshouldbe read together with the rest ofthe IPCC First Assessment Report

(see section 3 below).

ii. In the event of the continultionof the work of IPCC, the Comm2tteeagreed that a body similar toitself could serve the followingneeds:

(a) to act as a focal point fordiscussions on the science of,impacts of, and possible responseoptions to climate change;

(b) to review the progress of theimplementation of therecommendationsof the Committee.

Under (a) the Committee pointedout the need to estimate the economiccosts and benefi ts associated withthe different response options inrelation to the needs for economicdevelopment.This is critically neededparticularly in the case of small

islandstates.Cotmtry-specificstudies,following the pattern of those doneunder the Montreal Protocol wouldbe valuable; developing countriesshould make every effort to undertakesuch studies jointly or otherwise.

Under (b) regional and sub-regionalco-operation should be promoted toincreasethe capacityof the developingcountries in, inter alia,

atrrosphericesearchand rronioringin generaldetection of climate changeclimate modelingsetting up climatological databanksobservations of greenhousegasesoceanic monitoring and research.

13



Specific projects for thispurpose and for enhancing publicawareness, information exchange andtraining, especially in advancedfields of research, should bedeveloped and implemented.

iii. The Committee pointed out thatthe plethora of meetings and theirconcurrent schedulings, whilenecessitated by the time pressureplaced on IPCC in the past fewmonths, made it very difficult toenable effective participation.More care should be devoted tobetter planning of the meetings inthe future.

iv. While the attendance of the

developing countries at IPCCmeetings has shown a commendableincrease, there are still notenough of them participating. Itwould be truly beneficial toencourage fuller participation bythe developing countries as thiswould improve the relevance ofIPCC findings and reports. Fullparticipation includes thedevelopment of national capacityto address the issues of concernsuch as the appreciation of the

scientific basis for climatechange, the potential impacts ofsuch change and evaluations ofpractical response strategies fornational applications.

v. In this context, the Commi tteerequested its Chairman to conveyto the Panel:

a) its conclusion that theimplementation of its recommended

actions need not and should notawait the· outcome of futurenegotiations on a climateconvention;

b) the need toassistance ofbilateral andorganizations to

mobilize themultilateral,

other fundingimplement its

recommended actions;

c) the need to appeal togovernments and other potentialdonors for continuing and increasedcontributions to the IPCC TrustFund on an urgent basis to further

encourage the participation of thedeveloping countries in IPC~activities. ~~

3. IPCC FIRST ASSESSMENT REPORT

3 . 1 . The Panel adopted theOverview to the IPCC First Asaessment;

Report. The Overview, as adopted,is given in the following pages.

3.2 The Panel defined its First

Assessment Report as follows:

**

the Overview,the Policymakers Summaries ofits three Working Groups andits Special Committee on theParticir:atirn of r : e v e l q : > i n . : J Q:untries,andthe full reports of its threeWorking Groups.

3.3 The Panel recommended that itsOverview be read not in isolation

but in conjunction with the restof its First Assessment Report.

4. DATE AND VENUE OF THE NEXT SESSlOO"OF THE PANEL

The Panel decided to meet inits next sessionafter the 45th sessionof the UN General Assembly and thefirst negotiating session on theframework convention on climatechange. The decision on the date

and venue was left to the Chairmanof the Panel.

50. CLOSING OF THE SESSION

The fourth plenary session ofthe Intergovernmental Panel on.Climate Change closed at 0305hrson Friday, 31 August 1990.

14



WMO UNEP

.~.

I N T E R G O V E R N M E N T A L P A N E L O N

C L IM A T E C H A N G E

IPCC FIRST ASSESSMENT REPORT

OVERVIEW

31 AUGUST 1990

- 15 -



TABLE OF CONTENTS

P R EF A-CE. .. • • • • .. • • .. .. .. .. .. .. • • • .. • .. .. 'I .. .. • • • .. .. • • • • .. II .. .. oil .. .. . . . . • .. .. .. • .. I .. .. .. 'I •

1.. SCIENCE I I .

2. IMPACTS " .

2.1 Agiculture and forestry .

2.2 Natural terrestrial ecosystems .

2.3 Hydrology and water resources .

2.4 Human settlements, energy, transport, andindustrial sectors, human health and air quality ...

2 .5 Oceans and coas tal zones .

2.6 Seasonal snow cover, ice and permafrost .

3. RESPONSES STRATEGIES ~ .

3.1 Roles of industrialized and developing countries ...

3..2 Optiens.. 11 0 i • . . . • '" . . • . . . . . . ' II . . • .. .. . . . . . . .. .. .. • • . . • • .. .. .. . . • I I I . . . . . . . .

4. PARTICIPATION OF DEVELOPING COUNTRIES .

5. INTERNATIONAL CO-OPERATION AND FUTURE WORK .

APPENDIX Emissions scenarios developed by IPCC .

ii

OVERVIEW IPCC

}page,;.:

iii

1

3

5

5

6

7

8

8

9

9

10

13

15

17



PREFACE

TO THE IPCC OVERVIEW

The IPCC First Assessment Report ~onsists of

* this IPCC Overview,

* the Policymakers Summaries of the three IPCCWorking Groups(concerned with assessment respectively of the science, impactsand response strategies) and the IPCC Special Committee onthe Participation of Developing Countries, and

* the three reports of the Working Groups.

TheOVerviewbrings together material from the four Policyrnakers Sununaries.It presents conclusions, proposes lines of possible action (including suggestionsas to the factors which might form the basis for negotiations) and outlinesfurther work which is required for a more complete understanding of theproblems of" climate change resul t ingfrom human activities.

Because the Overview cannot reflect all aspects of the problem which

are presented in the three full reports of the Working Groups and the fourPolicymakers Summaries, it should be read in conjunction with them.

The issues, options and strategies presented in the Report are intendedto assist policymakers and future negotiators in their respective tasks.Further consideration of the Report should be given by every governmentas it cuts across different sectors in all countries. It should be notedthat the Report reflects the technical assessment of experts rather thangovernment positions, particularly those governments that could not participatein all Working Groups of IPCC.

iii



This Overview reflects theconclusions of the reports of (i)the three IPCC Working Groups onscience I impacts, and responsestr at egies, a nd (ii) the policyrnake-rs Summaries of the IPCC Working

Groups and the IPCC SpecialCommittee on the Participation ofD ev el op in g C ou nt ri es .

1 • SCIENCE

This section is structuredsimilarly to the PolicyrnakersSummary of Working Group I.

We are certain of the following:

* There is a natural greenhouse

effect which already keeps theEarth warmer than it wouldotherwise be.

* Emissions resulting from humanactivities are substantiallyincreasing the atmosphericcon ce nt ra tion s of the green housegases: carbon dioxi de, me thane,chlorof luoroca rbons (CFC s) andni t rous oxide. These increaseswill enhance the greenhouseeffect, resulting on average in

an additional warming of theEarth Is surface. The maingreenhouse gas, water vapour,will increase. in response toglobal warming and furtherenhance it.

We calculate with confidence that:

* Some gases are potentially moreeffective than others atchanging climate, and theirrelative effectiveness can be

estimated. Carbon dioxide hasbeen responsible for over halfof the enhanced greenhouseeffect in the past, and islikely to remain so in thefuture.

* Atmospheric concentrations ofthe 10ng-1 ived gases (carbon

1

dioxide, nitrous oxide and theCFCs) adjust c r u . y slowly to changesof emissio ns . Con ti nu ed e missio nsof these gases at present rateswould commit us to increasedccncentraticnsfor centuriesahead.

The longer emissions continueto i nc re as e a t prese nt -d ay $ at es,the gre at er red uction s wourd h av eto be far cxn:::entratiO'lS to stab;]; ze

at a given level.

* For the four scenarios of futureemissions which IPCC has developedas assumptions (ranging from onewhere few or no steps are takento limit emissions, viz. I ScenarioA o r B us in es s as Usu al Sce na rio,through others with increasing

l ev el s o f c on tr ol s r es pe ct iv el ycalled Scenarios B, C and D),there will be a ebID] ;rq of equivalent;carbon dioxide concentrationsfrom pre-industrial levels byaI : :cut 2025, 2040 arrl 2050 inScerericsA, B, and C respectively (seethe section "Which gases are theI T O S t important?" in the PolicymakersSummary of Working Group I fora description of the concept ofequivalent carbon dioxide). Seethe Appendix for a description

of the I PCC e missio ns scen arios.

* Stabilizationof equivalentcarbondi oxide conce ntratio ns at a bouttwice the pre-industrial level\Olld occur under ScenarioD I:cMardsthe end of the next century.Imm ediate re duction s of over 60 %

in the net (sources minus sinks)e mi ss io ns f ro m h um an a ct iv it ie so f l on g- li ve d g as es w ou ld a ch ie ves ta bi li za ti on o f c on ce nt ra ti onat today Is Leve ls r methane

concentrations~d be stabilizedwith a 15-20% reduction.

* The human-caused emissions ofcarbon dioxide are much smallerthan the natural exchange ratesof carbon dioxide between theatmosphere and the oceans, andbetween the atmosphere and the



terrestrial system. The naturalexchange rates were, however,in close balance before human-induced emissions began; thesteady anthropogenic emissionsinto the atmosphere representa significant disturbance of thenatural carbon cycle.

Based on current model results. wepredict:

* An average rate of increase ofglobal mean temperature duringthe next century of about O . 3°Cper decade (with an uncertaintyrange of 0.2 - 0.5 °c per decade)assuming the IEee Scenario A(Business as Usual) emissionsof greenhouse g~ses; this isa more rapid increase than seenover the past 10,000 years.This will result in a likelyincrease in the global meantemperature of about 1°C abovethe present value by 2025 (about2 °e above that in the pre- .industrial period}, and 3°Cabove today's value before theend of the next century (about4°C above pre-industrial).The rise will not be steadybecause of other factors.

* Under the other IPee emissionsscenarios· which assumeprogressively increaSing levelsof controls, rates of increasein global mean·temperature ofabout 0.2 °e per decade (ScenarioB), just above O.1°e per decade(Scenario C) and about O.1°Cperdecade (Scenario D). The risewill not be steady because ofother factors.

* Land surfaces warmmore rapidlythan the oceans, and highernorthern lati tudes warm morethan the global mean in winter.

* The oceans act as a heat. sinkand: thus delay the full effectof a g-reenhouse- warming.

Therefore, wewould be committedto a further temperature risewhich would progressively becomeapparen t in the ensuing decadesand centuries. Models predictthat as greenhouse gases increase,the realized temperature riseat any given time is between s q ram 80% of the ccmnitted t~turerise .'

* Underthe IPCC Scenario A (Businessas Usual) emissions, an averagerate of global mean sea-levelrise of about 6 cm per decadeover the next century (with anuncertainty range of 3 - 10 emper decade), mainly due to thermalexpans ion of the oceans and themelting of some land ice. Thepredicted rise is about 20 emin global meansea level by~030,and 65 emby the end of the nextcentury .. There will be significantregional variations.

With regard to uncertainties, we notethat:

* There are manyuncertainties inour predictions particularly withregard to the timing, magnitudeand regional patterns of climatechange~ especially changes inpreCipitation.

These uncertainties are dueto CJJr :incx:l1pleteroerstamirqof s:1. .11XES cn:l siriG of ~gases and the responses ofclouds, oceans and polarice sheets to a change ofthe radiative forcing causedby increasing greenhousegas concentrations.

These processes are alreadypartially understood, andwe 'are confident that theuncertainties can be reducedby further research. How'ever,the complexity of the systemmeans that. we..cannot ruleout surprises.



Our judgement is that:

* Global mean surface airtemperature has increased by0.3 to O.6°C over the last 100years, with the five global-average warmest years being inthe 1980 t s. Over the sameperiod global sea-levelincreased by 10 to 20 em.These increases have not beensmooth in time, nor uniformover the globe.

* The size of the warming overthe last century is broadlyconsistent wi th the predictionby climate models, but is alsoof the same magni tude as naturalc li ma te v ar ia bi li ty . If thesole cause of the observedwarming were the human-madegreenhouse effect, then theimplied climate sensitivitywould be near the lower end ofthe range inferred from models. 'Thus the observe d increase couldbe largely due to this naturalvaria bility; a lterna tively thisvariability and other human

factors could have offset astill larger human-inducedgreenhouse warming. Theunequivocal detection of theenhanc ed greenhous e effect fromobservations is not likely fora decade or more.

* Measurements from ice coresgoing back 160,000 years showthat the Earth t s temperatureclos~ly paralleled the amountof carbon dioxide and methane

in the atmosphere. Al thoughwe do not know the details ofc ause and effec t, calculation sindicate that changes in thesegreenhouse gases were part,but not all, of the reasons forthe large (5-7°C) globaltemperature swings between iceages and interglacial periods.

* Natural sources and sinks 0fgreenhouse gases are sensitiveto a change in climate. Althoughmany of the response (feedback)processes a re poorly und erstood,i t a pp ea rs t ha t, a s c li ma te warms,these feedbacks will lead to anoverall increase, ratherfthana d ec re as e, i n n at ur al g re en ho us egas abundances. For this leason,climate change is likely to begreater t han t he estimate s giv enabove.

2. IMPACTS

The'report on im pacts of WorkingGroup II is based on the work of an umber of subgroups, using ind epen dentstudies which have used differentmethodolo gies. Based on the e xi-stingliterature, the studies hav~ usedseveral scenarios to assess thepotential impact s of climat e cnange.These have the features of:

L) an effective doubling ofCO 2 in the a tmosphere betweennow and 2025 to 2050;

i1) a consequent increase of

global mean temperature inthe range of 1.SoC to 4° -5°C;

iii) an unequal globaldistributionof this temperatureincrease,namely a smaller increaseof half the global mean inthe tropical regions and alarger increase of twice theglobal mean in the polarregions; and

iv) a sea-level rise of abouto . 3 - O . 5 m by 2050 a nd a bo ut1 m by 2100, together witha rise in the temperatureof the surface ocean layerof between 0.20 and 2.SoC.

These scenarios pre-date, butare in line with, the assessment ofWorking Group I which, for Scenario

1



A (Business as Usual) has estimatedthe magnitude of sea-level rise atabout 20 em by 2030 and about 65 emby the end of the next century.working Group I has also predicted

the increase in global meantemperatures to be about 1°C abovethe present value by 2025 and 3°ebefore the end of the next century.

Any pred icte d eff ects of cli matechange must be viewed in the contextof our present dynamic and changingworld. Large-scale natural eventssuch as El Nino can causesignificant impacts on agricultureand human settlement. The predictedpopulation explos~on will produce

severe impacts on land use and onthe demands for energy, fresh water I

food and housing, which will varyfrom region to region according tonational incomes and rates ofdevelopment. In many cases,' theimpacts will be felt most severelyin regions already under stress,mainly the developing countries.Human-induced climate change due tocontinued uncontrolled emissionswill accentuate these impacts. Fori ns ta nc e, c li ma te c ha ng e, p ol lu ti on

and ul traviolet-B radiation fromozone depletion· can interact,reinforcing their damaging effectson materials and organisms.Increases·in a tmospheric con centra -tions of greenhouse gases may leadto irreversible change in theclimate whic~ could be detectableby the end of this century.

Comp rehe nsi ve es tima tes of .th ephysical and biological effects ofclimate change at the regional level

are difficult. Confidence inregional estimates of criticalclimatic factors is low. This isparticularly true of precipitationand soil moisture, \otherethere isconsiderable disagreement betweenvarious general circulation modelan d pa laeo anal og r esul ts. Mor eove r,there are several scientificuncertainties regarding the

OVERVIEW IPCC

rel atio nshi p betw een clim ate ch angeand biological effects and betweenthese effects and socioeconomicconsequences.

This impact study part of theOverview does not attempt toanticipateany adaptaticn,technolcgi~innovation or any other measures ~od imin ish the a dverse effects of clima techange that will take place in thesame time frame. This is especiallyimporta nt for hea vily man aged sectors,e.g., agriculture, forestry and publichealth.

Finally, the issue of timing andrates of change need to be considered;

there will be lags between:i ) emis sion s o f g reen hous e_ga ses

ani d:clllin3 of a:n::entraj:ioos;

ii) doubling of greenhouse gasconcentrations and changeil1climate;

iii) changes in climate andresultant r:hysical ani biolcgicaleffects; and .

iv) ~ in'tftysical ard emJcgicaleffects arl :re9.Jl.t:nt s:r:i, ecrranic

(including· ecological)consequences. The shorterthe lags, the less theabilityto oceeard tbegreatert he soci oeco nomi c i mpac ts.

There is uncertainty related tothese time lags. The changes willnot be steady and surprises cannotbe ruled' out. The severity of theimpacts will depend to a la:rgedegree

on the rate of climate change.

Despitetheseuncertainties,Working

Group II has been able to reach somemajor con clusions. These a re presentedbelow.

4



2. 1 Agriculture and forestry

Sufficient evidence is nowavailable from a variety ofdifferent studies to indicate thatchanges of climate would have an

important effect on agriculture andlivestock. Studies have not yetconclusively determined whether, onaverage; global agriculturalpotential will increase or decrease.Negative impacts could be felt atthe regional level as a result ofchanges in wea ther and pes tsassociated with climate change, andchanges in ground-level ozoneassociated with pollutants,necessitating innovations intechnology and agricultural

management practices. There may besevere effects in some regions,particularly decline in productionin regions of high present-dayvulnerability that are least ableto adjust. These include Brazil,Peru, the Sahel Region of Africa,Southeast Asia, and the Asian regionof the USSR and China. There is apossibility that potentialproducti vi ty of high and midtati tudes may increase because ofa prolonged growing season, but it

is not likely to open up large newareas for production and it will bemainly confined to the NorthernHemisphere.

Patterns of agricultural tradecould be altered by decreased cerealproduction in some of the currentlyhigh-production areas, such aswestern Europe, southern USA, partsof South America and westernA us tr al ia . H or ti cu lt ur al p ro du ct io nin mid-latitude regions may be

reduced. On the other hand, cerealproduction could increase innorthern Europe. Policy responsesdirected to breeding new plantcultivars, and agriculturalmanagement designed to· cope wi thchanged climate conditions, couldlessen the severity of regionalimpacts. On the balance, the

evidence suggests that in the faceof estimated changes of climate,food production at the global levelcan be maintained at essentiallythe same level as would have occurredwithout climate change; however,

the cost of achieving this is unclear.N:::neilieless,limatechangemay intensifydifficulties in coping with ,@!-apidp op Ul at io n g row th . An incrEtase orchange in UV-B radiation at groundlevel resulting from the depletionof stratospheric ozone will have anegative impact on crops and livestock.

.,

The rotation period of forestsis long and current forests will maturea nd d ec li ne d ur in g a climate in whichthey are increasingly more poorly

adapted. Actual impacts depend onthe phYSiological adaptabili~y oftrees and the host-parasiterelationship. Large losses from bothfactors in the form of forest declinescan occur. Losses from wildfire willbe increasinglyextensive. The climatezones which control speciesdistribution will move poleward andt o h ig he r e le va ti on s. Ma na ge d f or es tsr eq ui re l ar ge i np ut s in t erm s o f c hoi ceof seedlot and spacing, thinning andprotection. They provide a variety

of products from fuel to food.

'!he degree of dependency 00 prcductsvaries among countries, as does theability to cope with and to withstandloss. The most sensitive areas willbe where speCies are close to theirbiologicallimitsintermsof temperatureand moisture. This is likely to be,for example, in semi-arid areas.Social stresses can be expected toincrease and consequent anthropogenicdamage to forests may occur. These

increased and non-sustainable useswill place more pressure on foresti nv es tm en ts , f or es t c on se rv at io n a ndsound forest management.

2.2 Natural terrestrial ecosystems

Na tu ra l t er re st ri al e cos ys te msc ou ld f ace s ig ni fi ca nt c on se qu en ces

5



as a result of the global increasesin the atmospheric concentrationsof greenhouse gases and theassociated climatic changes.Projected changes in temperature and

pre ci pi t ati on s ugg est tha t cl im ati czones could shift several hundredkilometres towards the poles overthe next fifty years. Flora andfauna would lag behind theseclimatic shifts, surviving in theirpresent location and, therefore,could find themselves in a differentclimatic regime. These regimes maybe more or less hospitable and,therefore, could increaseproductivity for some species anddecrease that of others. Ecosystems

are not expected to move as a singleunit, but would have a new structureas a consequence of alterations indistribution and abundance ofspecies.

The rate of projected climatechanges is the major factordetermining the type and degree ofclimatic impacts on naturalterrestrial ecosystems. These ratesare likely to be faster than theability of some specie~ to respond

and responses may be sudden orgradual.

Some species could be lost owingto increased stress leading to areduction of global biologicaldiversity. Increased incidence ofdisturbances such as pest outbreaksaridfire are likely to occur in someareas and these could enhanceprojected ecosystem changes.

Consequences of CO2 enrichment

and climate change for naturalterrestrial ecosystems could bemodified by other environmentalfactors, both natural and man-induced (e.g. by air pollution).

Most at risk are thosecommuni ties in which the options foradaptability are limited (e.g.man tane, alpine, polar, i51and and

coastal communities, remnantvegetation, and heritage sites andr es er ve s) a nd t ho se c om mu ni ti es w he reclimatic charq!s add to exist.in; stresses.

The socioeconomic consequences of

these impacts will be significant,especially for those regions of the.globe where societies and related~economies are dependent on naturalterr estri alecosy stansfor theirwelfare.Ch ang es i n t he av ai lab ili ty of food,fuel, medicine, construction materialar:rl iocote are p::ssible as t:h:!Se ecnsystans

a re c ha ng ed . I mp or ta nt f ib re p ro d1 .1 ct scould also be affected in some regions.

2.3 Hydrology and water resources

Re la ti ve ly s ma ll c li ma te c ha ng escan cause large water resource problemsin many areas, especially arid andsemi-arid regions and those humidareas where demand or pollution hasled to water scarcity. Little isknown about regional details of.greenh:use-gas-:i.rrlJ.red hydrt:netearolcgicalchange. It appears that many areaswill have increased precipitation,soil moisture and water storage, thusaltering patterns of agricultural,ecosystem and other water use. Water

availability will decrease in otherareas, a most important factor foralready marginal situations, suchas the Sahelian zone in Africa. Thishas significant implications foragriculture, for water storage anddistribution, and for generation ofhydroelectric power. In some limi tedareas, for example, under an assumedscenario of a 1°C to 2°C temperaturei nc re as e, c ou pl ed w i t h a 1 0% r ed uc ti onin p rec ip ita ti on, a 40 -70% re du cti onin annual runoff could occur.

Regions such as southern Asia, thatare dependent on unregulated rivers ys te ms , a re p ar ti cu la rl y v ul ne ra bl eto hydrometeorological change. Onthe other hand, regions such as thew es te rn US SR a nd w es te rn Un it ed S ta te sthat have large regulatedwater resourcesystems are less sensitive to ther an ge o f h yd ro me te or ol og ic al c ha ng esin the as sum ed s cen ar io. In addition

6



to changes in water supply, waterdemand may also change through humanefforts to conserve, and throughimproved growth efficiency of plantsin a higher CO2 environment. Netsocioeconomic consequences mustconsider both supply and demand forwater. Future design in waterresource engineering will need totake possible impacts into accountwhen considering structures with alife span to the end of the nextcentury. Where precipitationincreases, water managementpractices, such as urban stormdrainage systems, may requireupgrading in capacity. Change indrought risk represents potentiallythe most serious impact of climatechange on agriculture at bothregional and global levels.

2.4 Human settlements, enerov.transport. and industrialsectors. human health and airquality

The most vulnerable humansettlements are those especiallyexposed to - natural hazards, e .g .coastal or river flooding, severedrought, landslides, severe wind

storms and tropical cyclones. Themost vulnerable populations are indeveloping countries, in the lower-income groups: res idents of coas tallowlands and islands, populationsin semi-arid grasslands, and theurban poor in squatter settlements,slums and shanty towns, especiallyin megaci ties. In coastal lowlandssuch as in Bangladesh, China andEgypt, as well as in small islandnations, inundation due to sea-levelrise and storm surges could lead to

significant movements of people.Major health impacts are possible,especially in large urban areas,owing to changes in availability ofwater and food and increased healthproblems due to heat stressspreading of infections. Changesin precipitation and temperaturecould radically alter the patterns

of vector-borne and viral diseasesby shifting them to higher lati t udes r

thus putting large populations atrisk. As similar events have in thepast, these changes could initiatelarge migrations of people, leading0l'eI a ruri:er of years to se.e:e di.s:rtpt:i.msof settlement patterns and ~cialinstability in some areas. ~. .::

Global warming can be expectedto affect the availability of waterresources and biomass, both majorsources of energy in many developingcountries. These effects are likelyto differ between and wi t hin regionswi th some areas losing and othersgaining water and bia na ss . Such cha ng esi n a re as which lose w at er m ay j eopa rd izee ne rg y s up pl y a nd m at er ia ls e ss en ti alfor human habitation and energy.Moreover, climate change itself isalso likely to have different effectsbetween regions on the availabili tyof other forms of renewable energysuch as wind and solar power. Indevelopedcountriessane of the greatestimpacts on the energy, transport andindustrial sectors may be determinedby policy responses to climate changesuch as fuel regulations, emissionfees or poliCies promoting greater

use of mass transit. In developingcountries, climate-related changesin the availability an:l prire of prcdxtim

resources such as energy, water, foodand fibre may affect the competi ti veposition of many industries.

Global warming and increasedu lt ra vi ol et r ad ia ti on r es ul ti ng f ro mdepletion of stratospheric ozone mayp ro du ce a dv er se i mp ac ts o n a ir q ua li tysuch as increases in ground-levelozone in some polluted urban areas.

An increase of ultraviolet-B radiationi nt en si ty a t t he Ea rt h Is s ur fa ce w ou ldincrease the risk of damage to theeye and skin and may disrupt the marinefood chain.

7



2.5 Oceans and coastal zones

Global warming will acceleratesea-level rise, modify oceancirculation and change marineecosystems, wi th considerablesocioeconomic consequences. Theseeffects will be added to presenttrends of rising sea-level, andother effects that have alreadystressed coastal resources, such aspollution and over-harvesting. A30-50 em sea-level rise (projectedby 2050) will threaten low islandsand coastal zones. A 1 m rise by2100 would render some islandcountries uninhabitable, displacetens of millions of people,

seriously threaten low-lying urbanareas, flood productive land,contaminate fresh water supplies andchange coastlines. All of theseimpacts would be exacerbated ifdroughts and storms become moresevere. Coastal protection wouldinvolve very significant costs.Rapid sea-level rise would change.coastal ecology and threaten manyimportant fisheries. Reductions insea ice will benefit shipping, butseriously impact on ice-dependent

marine mammals and birds.Impacts on the global oceans

will include changes in the heatbalance, shifts in ocean circulationwhich will affect the capacity ofthe ocean to absorb heat and CO2 andchanges in upwelling zonesassociated with fisheries. Effectswill vary by geographic zones, withchanges in habitats, a decrease inbiological diversity and shifts inmarine organisms and productive

zones, including commerciallyimportant species. Such regionalshifts in fisheries will have majors oc io ec on om ic im pa ct s.

2.6 Seasonal snow cover« ice andpermafrost

The global areal extent andvolume of elements of the

terrestrial cryosphere (seasonalsnow cover, near-surface layers ofpermafrost and some masses of ice)will be substantially reduced.'Trese redoctims, W"al . reflecterl regicrally

could have significant impacts onrelated ecosystems and social andeconomic activities. Compoundingth es e i mp act s in so me re gio ns is that,as a result of the associated climaticwarming posttive fee:Jbacks, the redtrtimscould be sudden rather than gradual.

The areal coverage of seasonalsnow and its duration are projectedto decreaseinnost regiens,particularlyat mid latitudes, with some regionsat high latitudespossibly experiencingincreases in seasonal snow cover.Changes in the volume of snow cover I

or the length of the snow cover season,will have both positive and negativeimpacts on regional water resources(as a resul t of changes in the volumeand t he t im in g o f r un of f fran snowmelt),-o n regional transportation (road,marine, air and rail), and on recreationsectors.

Globally, the ice contained inglaciers and ice sheets is projected

to decrease, with regional responsesc om pl ic at ed b y t he e ff ec t o f i nc re as edsnowfall in some areas which couldl ea d t o a cc um ul at io n of ice. Glacialrecession will have significantimplications for local and regionalwater resources, and thus impact onwater availabilityand an hydroelectricpower potential. Glacial recessionand loss of ice from ice sheetswill also contribute to sea-levelrise. Permafrost, which currentlyunderlies 20-25% of the land mass

of the Northern Hemisphere, coulde xpe ri en ce si gn ifi ca nt d eg rad at io nw it hi n t he n ex t 40-50 y ea rs . Pr oj ec te dincreases in the thickness of thefreeze-thaw (active) layer above thepennafrostand a recessiooof permafrostto higher latitudes and altitudescould lead to increases in terrainin st ab il i ty , er os io n a nd la nds li de si n t ho se a re as w hi ch c ur re nt ly c on ta in

8



permafrost. As a result, overlyingecosystems could be significantlyaltered and the integrity of man-made structures and facilitiesreduced, thereby influencingexisting human settlements and

development opportunities.

3. RESPONSE STRATEGIES

The consideration of climatechange response strategies presentsformidable difficulties forpolicymakers. The informationavailable to make sound policyanalyses is inadequate because of:

(a) uncertainty wi th respect to howeffective specific response

options or groups of optionswould be in actually avertingpotential climate change;

(b) uncertainty wi th respect to thecosts, effects on economicgrowth, and other economic ands oc ia l im pl ic at ion s of s pe ci fi cresponse options or groups ofoptions.

The IPCC recommends a programmefor the development and implementa-

tion of global, comprehensive andphased action for the resolution ofthe global warming problem under aflexible and progressive approach.

* A major dilemma of the issue ofclimate change due to increasingemission of greenhouse gases inthe atmosphere is that actionsmay be required well before manyof the specific issues that areand will be raised can beanalyzed more thoroughly byf ur th er r es ea rc h.

* The CFCs are being phased outto protect the stratosphericozone layer. This action willalso effectively slow down therate of increase of radiativeforcing of greenhouse gases inthe atmosphere. Every effort

OVERVIEW IPO::

should be made to find replacements

th at ha ve l it tl e o r n o gr een ho us ewa.nnin;J p::Itential or ozcne depleticnpotential rather than the HCFCsand HFCs that are now beingconsidered.

* T he s in gl e l ar ge st a nt hr op og en icsource of radiative forcing isenergy production and use. Theenergy sector accounts for anestimated 46% (with an uncertaintyrange of 38-54%) of the enhancedr ad ia ti ve f or Ci ng r es ul ti ng f ro mh um an a ct iv it ie s. 2

* It is noted that emissions duet o f os si l f ue l c om bu st io n a mo un tsto about 70-90% of the total

anthropogenic emissions ~f CO2into the atmosphere, whereas theremaining 10-30% is due to 'humanuse of terrestrial ecosys.tems.A major decrease of the ra-teofdefo rest atic nas well as an i nc re as ein afforestation would contributes ig ni fi ca nt ly t o s lo wi ng t he r at eof CO2 co nc en tr at ion s i nc re as ein the atmosphere; but it wouldbe well below that required tostop it. This underlines thatwhen forestry measures have been

introduced, other measures tolimitor reducegreenhc:use emissicns:should not be neglected.

3.1 Roles of industrialized andde vel op in g c ou nt rie s

* Industrialized and developingc ou nt ri es h av e a c ar mo n b ut v ar ie dresponsibility in dealing withthe problem of climate changeand its adverse effects. Theformer should take the lead intwo ways:

i) A major part of emissionsaffecting the atmosphere atpresent originates in

industrialized aJ\lI1trieswheret:re sa:p! fi:r d ' 1 i : l ' l 3 e is greatest.Irrlustrialized cx::untries sl'x:uld

adopt domestic measures to

9



limit climate changeadapting theireconomies in linefuture agreements to

byown

withlimit

emissions.

*

ii) To co-operate withdeveloping countries ininternational action,wi thout standing in the wayo f t he l at te r's d ev el op me ntby co ntri buti ng addi tion alfinancial resources, byappropriate transfer oftechnology, by engaging inclose co-operation inscientific observation,analysis and research, and

finally by means oftechnical co-operationgeared to forestalling andmanaging environmentalproblems.

Sustainable development1 inindustrialized as well asdeve lopi ng co untr ies requiresp ro pe r c on ce rn f or e nv ir on me nt alprotection as the basis forcontinued economic growth.Environmental considerations

must be systematicallyintegrated into all plans fordevelopment. The right balancemust be struck between economicgrowth and environmentalobjectives~

* Emissions from developingcountries are growing in orderto meet their developmentrequirements and thus, overtime, are likely to representan increasingly significant

1. Sustainable development is development·that meets the needs .of the present wi thoutcompromising the abili ty of futuregenerations to meet their own needs and doesnot imply in any ."ay encroachment uponnational sovereignty. (AnnexII to decision15/2 of the 15th sessionol the UNEPGoverning Council; ·.Nairobi, Hay 1989)

p erce ntag e o f g loba l emis sion s.As the greenhouse gas emissionsin&:!vel.cping co.ntries are :in:reas.irq

with their population and economicgrowth, rapid transfer, on a

preferential basis, to developingc ou nt ri es , o f t ec hn ol og ie s w hi chhelp to monitor, limit or adaptto climate change, with::uthin:ieringtheir economic development, isan urgent requirement. Developingcountriesshould, within the limitsfeasible,take measures to suitablyadapt their econanies. Recognizingthe poverty that prevails amongthe populations of developingcountries, it is natural thatachieving econanic growth is given

priori ty by them. Narrowing thegap between the industrializedand developing world would providea basis for a full partnershipof all nations in the worl~ andwould assist developing countriesi n d ea li ng w i th t he c li ma te c ha ng eissue.

3.2 Options

* The climate scenario studies ofW or ki ng G ro up s Iand III outline

control policies on emissionsthat would slow global warmingfrom the presently predicted valueof a bout O. 3°C per dec ade t o abo ut0.1 °C per decade (see Appendix) .

'!he potentiallyseriousCCl'lSeqUeIlCeSo f c li ma te c ha ng e g iv e s uf fi ci en treasons to begin adopting responsestrategies that can be justifiedimmediately even in the face ofs ig ni fi ca nt u nc er ta in ti es .T heresponse strategies include:

*

o phasing out of CFC emissionsand careful assessment oft he g re en ho us e g as p ot en ti alof proposed substitutes;

1'{)



o efficiency improvements andconservation in energysupply, conversion and enduse, in particular throughimproving diffusion ofenergy-efficient tech-

nologies, improving theefficiency of mass-producedgoods, reviewing energy-related price and tariffsystems to better reflecte nv ir on me nt al c os ts ;

sustainable forestmanagement and afforesta-tion; .

o use of cleaner, moreefficient energy sources

with lower or no emissionsof greenhouse gases;

o review ofpractices.

agriculture

* There is no single quick-fixtechnological option forlimiting greenhouse gasemissions. phased and flexibleresponse strategies should bedesigned to enhance . relevanttechnological research,

development and deployment,including improvement andreassessment of existingtechnologies. Such strategiesshould involve opportunities forinternational co-operation. A

comprehensive strategyaddressing all aspects of theproblem and reflectingenvironmental, economic andsocial costs and benefits isnecessary.

* Because a large, prOjectedincrease in world populationwill be a major factor incausing the projected increasein global greenhouse gases, iti s e ss en ti al t ha t g lo ba l c li ma techange strategies take intoaccount the need to deal with

11

the issue of the rate of growthof the world population.

* Subject to their particularcircumstances, individualnations, or groups of nations,

may wish tq consider takingsteps now to attempt to limit,stabi lize or reduce the emissionof greenhouse gases resultingfrom human activities and preventthe destruction and improve theeffectivenessof sinks. One optionthat ~ts nay wish to cx::nsideris the setting of targets forCO2 . and other greenhouse gases.

* A large number of options werepreliminarily assessed by IPCC

Working Group III. It app earsthat some of these options maybe e:x:n:ndcally am so:ially feasililefor implementation in the near-term w hile ot hers, because theyare not yet technically oreconomi cally viable, may be mor ea pp ro pr ia te f or i mp le me nt at io nin the longer term. In general,the Working Group found that therrosteff ectiverespcnse strategies,espeCially in the short term,are those which are:

o beneficial for reasons otherthan climate change andjustifiablen their ow n right,for exa mple increased energyefficienCyam lcwer greE!fll'x:use

g as e mi ss io n t ec hn ol og ie s,better managementof forests,a nd other n atural resources,and reduc tions in emiss ionsof CRS an cth:r ozcre d;pl.et::in;substances that are alsoradiatively important gases;

a econo mically ef ficient andcost effective,in particulart ho se t ha t u se m ar ke t- ba se dmechanisms;

o able to serve multipleSOCial, economic andenviron mental purposes;



o flexible and phased, sothat they can be easilymodified to respond toi nc re as ed u nd er st an di ng o fscien tific, techn ologicaland economic aspects ofcli mate ch ange ;

o compatible with economicgrowth and the concept ofsusta in able d evelopment;

o administratively practicaland effective in terms ofapplication, monitoring andenforcement;

o reflecting obligations ofboth industrialized anddeveloping countries inaddressing this issue,while recognizing thespecial n eeds of d evelopin gcbuntries, in particularin the areas of financinga nd t ec hn ol og y.

The degree to which options areviable will also vary considerablydepending on the region or country

invol ved . For each country, theimplications of specific optionswill depend on its social,en viro nmen tal an d ec onomi c con text .Only through careful analysis of allavailable options will it bepossible to determine which are bestsui ted to the circumstances of aparticular country or region.Initially, the highest priorityshould be to review existingpolicies with a view to minimizingconflicts with the goals of climate

change strategies. New policieswill be required.

* In the long-term perspective,work should begin on definingcriteria for selection of ap-propriate options which wouldreflect the impacts of climatechange and its costs and· bene fits on ·th e one hand, and

12

social and economic costs andbenefits of the options on theother.

* Consideration of measures forreducing the impacts of globalclimate change should begin assoon as possible, particularlywith regard to disasterprep ared ness po lici es, coas talzone management and controlmeasures for desertification,many of these being justifiedin their own right. Measpresto limi t or adapt to climatechange should be as cost-effectiveas possible while taking intoac:xxllIlt :inp:D:tcln.t sxi al inplicatials.Limitation a nd a da ptation shouldbe considered as an integ+atedpackage.

* Assessing a reas a t risk from..ea-level -rise and developingcomp rehe nsiv e man agem ent pla nsto ~educe future vulnerabilityof populations and coastaldevelopments and ecosystems aspart of coastal zone managementplans should begin as soon aspossible.

* Env iron ment al o bjec tive s can bepui's uedth roughregul ation sani l / orthrough market based economicinstruments. The latter, throughtheir encouragement of·flexibleselection of a ba tement mea sures,te nd to enco urag e inno vati on an dthe development of improvedtechnologies and practices forred ucin g emissions a nd thereforefrequen tly offer the possibili tyof achieving environmental

imp rove ment s a t lowe r co sts t hant hr ou gh r eg ul at or y m ec ha ni sm s.It is not likely, however, thateconomic instruments. will beapplicable to a_11circumstances.

* Three factors are considered aspotentialbarriers to the operatiooof markets a nd /or the a chievementof enViL'OlAliental c:bjectives.lu:ough



market mechanisms. These are:

i) information problems, whichcan often cause markets toproduce less effective or

unfavourable environmentaloutcomes;

ii) existing measures andinstitutions, which canencourage individuals tobe hav e i n e nv ir onm ent al lydamaging ways; and

iii)balancing competingobjectives (social,environmental ande co no mi c) .

An initial response strategy maytherefore be to address informationproblems directly and to reviewexisting measures which may bebarriers. For example, prior topossible adoption of a system ofemission charges, countries shouldexamine existing subsidies and taxincentives on energy and otherrelevant greenhouse gas producingsectors.

* With respect to institutionalmechanisms for providingfinancial co-operation andassistance to developingcountries, a two track approachw as c on si de re d:

i) one track built on workunderway or planned inexisting institutions.Bilateral donors couldfurther integrate andreinforce the environmental

components of theirassistance programmes anddevelop cofinancingarrangements withmultila tera l institution swhile ensuring that thisdoes not impose inap-propriate environmentalconditions.

ii) parallel to this track thepossibility of new mechanismsand facilitieswas considered.

SelIe develq>in:J a m . industrial-ized countries suggested

tha t n ew mecha nisms d irectlyrelated \::0 a future climateconventionand protocolsthatmight be agreed upon, suchas a n ew interna tion al fun d,w er e re qui red .

* Governmentsnow:

should undertake~

o accelerated and co-ordinatedresearchprogramnesto reducescien tific a nd socioecon om-

i c un cer ta int ies wi th a vi ewt owa rds i mpr ovi ng t he ba sisfor response strategiesa nd me asu re s;

o review of planning in thefi eld s of e ne rg y, i nd us try ,transportation,urban areas,coastal zones and resourceuse and management;

o encouragement of beneficialbehavioral and structural

(e.g.t:ransp:rtaticn am l'l:uslngi nf ra st ru ct ur e) c ha ng es ;

o expan sion of the globa l oceanobserving and monitoringsystems.

I t s ho ul dbe n oted tha t n o d etailedassessments have been made as of yetof the economic costs and benefits,t ec hn ol og ic al f ea si bi li ty o r m ar ke tpotential of the underlying policy

assumptions.

It is obvious that the impacton and the participation by thedeveloping countries in the further

13



development of a future strategy isessential. The IPCC has attemptedto address this specific issue byestablishing a Special Committee onthe Participation of Developing

Countries and requested it toidentify factors inhibiting the fullparticipation of the developingcountries in IPCC and recommendremedial measures where possible.The Committee stressed that fullparticipation includes not only thephysical presence at meetings bu.talso the development of nationalcompetence to address all issues ofconcern such as the appreciation ofthe scientific basis of climatechange, the potential impacts on

society of such change andevaluations of practical responsestrategies for national/regionalapplications.

The factors that kept developingcotintries from fully .participating were identified by theSpecial Committee as:

o i ns uf fi ci en t i nf or ma ti on ;o insufficient conununication;o limited human resources;

o institutional difficulties;o limited financialresources.

On some of these factors, theIPCC Working GroupS have'developed policy options which areto be found in their.respective reports.

* Developing countries will, insome cases, need additionalfinancial resources for

supporting their efforts topromote activities whichcontribute both to limitingg re en ho use ga s em is si ons an d/oradapting to the adverse effectsof climate change, while at thesame time promote economicdevelopment. Areas of co-opexat.Lorrcpuldinclude, interalia:

1i

o efficient use of energyresources, the use of fossilf ue ls w it h l ow er gr een ho us egas emission rates or non-

fossil sam:::es, the deve1q:mentof clean and renewableenergy sources, such as:b io ma ss , w in dp ow er ,w av e-power, hydroelectric andsolar, wherever applicable;

o . increased rationalutilizationof forest products, soundforest management practicesand agricultural·techniqueswhich reduce the negativeeffects on climate;

o facilitating the develop-ment and transfer of Cleanand safe technologie-s inareas which could Lnc.Iude :

o

the building andmanufacturing·irrlustries;public tzansport; systems;industry;

measures which enhance thecapacity of developing

o:u1tries to develcpprog:rauuesto address ciimate change,i,ncluding research anddevelopment activities andPublicawarenessand educationprogrammes, such as:

the development of thehuman resourcesnecessaryto tackle the problemof climate change andits adverse effects;

the provision of studya nd t ra in in g p ro gr an un esin subjectsam techniquesrelated to clinatechange;

t he p ro vi si on o f s kil ledpersonne!". and thematerial necessary toorganize educationprogrammes to develop



-

the skillsto assess

change andits adverse

locallynecessaryclimatecombateffects;

the development ofclimate-relatedresearch programmesorganized on areg iona l basi sj

o facilitating the participa-tion of developingcountries in fora andorganizations such as: theI nter nati onal Geos pher e-Biosphere programme, theL and- Ocea n In ter- acti onsin the Coastal Zone, theBiosphere Aspects of theHydrological Cycle, theGlobal Change Impac t onAgriculture and Society 1

t he W or ld C li ma te p ro gr am m-e, the Man and theB io sp he re Pr og ra mm e;

o facilitating participationb y d ev el op in g . co un tr ie s i ninternational fora onglobal climate change suchas the IPCC;

o strengthening existingeducation and. researchinstitutions and thedevelopment of new ones atnational and regionallevels.

* Further, co-operation anda ssista nce for a da ptive mea sureswould be required, noting that

for some regions and countriesI

adaptation rather than limita-t io n a ct iv it ie s a re p ot en ti al lymost i mpor tant .

* The IPCC concludes that therecommendations of the SpecialCommittee need not and shouldnot await the outcome of futurenegotiations on a climate

convention. It appeals to themultilateral and bilateralfundingorganizationsto implementits recorrunendations.It furtheraw'f!] s to gJVem'IBlts for cx:nt . i .nr i .n;J

and increased contributions tothe IPCC Trust Fund on an urgentbasis.

5. INTERNATIONAL CO-OPERATION ANDFUTURE WORK

*•

The meas ures note d abo ve r equi rea high degree of interna-tionalco-6peration with due respectfor national sovereignty ofstates. The internationalnegotiations on a frameworkconvention should start asquickly as possible afterpresentation of this Report inline with Resolution SS "-II/3Climate. C. (August 1990) of thelNEP Q:Jverni.r:g Co.m:::il arrl Resolutim

8 (EC-XLII,. June 1990) of theWMO Executive Council. Many,essentiallydevelop-ing,countriesstressed that the negotiationsmust be conducted in the forum,manner and with the timing tote decided by the W ~ Assatbly.

'!h iscon ven tioo,and any additionalprotocols that might be agreed upon,would providea firm basis for effectiveco-operation to act on greenhousegas emissions and adapt to anyadverse effects of climate change.The conventionshould recognizeclimatechange as a common concern of mankindand, at a minimum, contain generalprinciples and obligations. It should

be framed in such a way as to gaint he adh eren ce of th e l arge st p ossi blenumber and most suitably balancedrange of countries while permittingtimely action to be taken.

Ke y issu es for ne goti atio ns wil linclude the criteria, timing, legalfo rm a nd i ncid ence of any obli gati onsto centro! the ret emissicns of greenb:JUse

15



gases, how to address equitably theconsequences for all, anyinstitutional mechanisms includingresearch and monitoring that mayberequired, and in particular, the

requests of the developing countriesfor additional financial resourcesand for the transfer of technologyon a preferential basis. Thepossible elements of a frameworkconvention on climate change wereidentified and discussed by WorkingGroup III in its legal measurestopic paper, appended to itsPolicymakers Summary.

* The IPCC recommends that

research regarding the science ofclimate changein general, teclmolcqicaldevelopment and the internationaleconanic implications I be intensified.

* Because climate change wouldaffect, either directly orindirectly, almost every sectorof society, broad globalunderstanding of the issue willfaciLdtate the adoption and theimplementation of such responseoptions as deemednecessary andappropriate. Further ef£ortsto achieve such global understand-ing are urgently needed.

"_

16



l

APPENDIX

Emissions scenarios developed by IPCC

The IPCC used two methods to develop scenarios of future emissions:

* One method used global models to develop four scenarios which weresubsequently used by Working Group I to develop scenarios of futurewarming. All of these four scenarios assumed the same global economicgrowth rates taken from the world Bank projections and the same populationgrowth estimates taken from the Uni ted Nations studies. The anthropogenicemissions of carbon dioxide and methane from these scenarios areshown in Figures 1 and 2 below.

* The second method uaed studies of the energy and agriculture sectorss ubm itt ed b y o ve r 21 c ou ntr ies a nd i nt ern ati ona l o rga niz at io ns t o e st ima teCO 2 emissions. ".

Both scenario approaches indicate that CO2 emissions will grow fromabout 7 BtC (billion or 1000 million tonnes carbon) per year now co 12-15 BtC per year by the year 2025. Scenario A (Business as Usual) includesa partial phase-out of CFCs under the Montreal Protocol and lower CO 2 andCH4 emissions than the Reference Scenario. The Reference Scenario developedthrough country and international ·studies of the energy and agriculturegroups, includes higher CO2 emissions and assumed a total CFC phase-out.The results indicate that the CO 2 e qui va le nt c on ce ntr ati ons a nd t he ir e ff ec tson global climate are :similar.

Figure 1. Projected Man-Made CO2 Emissions(Billion or 1000 million tonnes carbon per year)

BUSINISS

AS-USUAL

~ ~~~~

s c : E N A A I O C

SCENARIO 0O'_~~~~~~~T-~~--~~~--1

19S0 2000 2020· 2040 2080 2010 2100

YEA"

17



Figure 2. Projected Man-Made Methane Emissions(Million tonnes per year)

seeBUS INESS

-.i ...S·USUAL" :I:J S O C (SC!HAFUO A)

1l.I)o, .

Z.....C

= , w 700

"'z1-600

iii'"cZ S C E : " iA R 1 0 B

I i S O O

'lit_c .'00...

SCENAAOO

30019'0 .2000 2020 20'0 2~60 .20'0 2100

YI iA"

Method 12

Scenario A (Business as Usual) assumes that few or no steps are takento limit greenhouse gas emissions. Energy use and clearing of tropicalforests continue and fossil fuels, in particular coal, remain the world'sprimary energy source. The Montreal Protocol comes into effect but withoutstrengthening and with less than 100 percent compliance. Under this scenario,

the equivalent of a doubling of pre-industrial CO 2 le vel s o ccu rs, ac co rd ingto Working Group I, by around 2025.

Scenario B (Low Emissions Scenario) assumes that the energy supplymix of fossil fuels shifts towards natural gas, large efficiency increases

2 All of the scenarios assumed some level of compliance withthe Montreal Protocol but not with all of the (June 1990)amendments agreed to in London. The London amendments to theMontreal Protocol, when fully implemented, would result in avirtually complete elimination of production of fully halogenatedCFCs, halons, carbon tetrachloride and methyl chloroform early

in the 21st century. The Parties of the Protocol also call forlater elimination of HCFCs. Thus, the assumptions of ScenariosA and B overestimate the radiative forcing potential of CFCs andhalons. Additionally, the UN has provided recent populationprojections that estimate high~r population than used in theglobal model scenarios (Scenarios A through D); use of thesen ewe r p ro je ct ion s wo ul d in cre as e f utu re C O2 emissions. Additionally,the Reference Scenario CO 2 emissi(:>nsare higher than Scenario A(Business as Usual), suggestin. Scenario A (Business as Usual)may be an underestimate.

18



--

are achieved, deforestation is reversed and emissions of CFCs are reducedby 50% from their 1986 levels. This results in an equivalent doublingof pre-industrial carbon dioxide by about 2040.

Scenario C (Control Policies Scenario) assumes that a shift towardsrenewable energies and safe nuclear energy takes place in the latter partof the next century, CFC gases are phased out and agricultural emissions(methane and nitrous oxide) are limited; an equivalent- doubling of pre-industrial carbon dioxide will occur in about 2050.

Scenario D (Accelerated Policies Scenario) assumes that a rapid shiftto renewable energies and safe nuclear energy takes place early in then ex t c en tu ry , s tr in ge nt e mi ss io n c on tr ol s i n i nd us tr ia l c ou nt ri es a nd m od er at egrowth of emissions in developing countries. This scenario, which aasumescarbon dioxide emissions are reduced to 50% of 1985 levels, stabilizesequivalent carbon dioxide concentrations at about twice the pre-industriallevels towards the end of the next century.

Method 2 (see footnote 2 on previous page)

Using the second method, the so-called Reference Scenario was deve.Lopedby the Energy and Industry Subgroup and Agriculture and Forestry Subgroupof Working Group III. Under the Reference Scenario, global CO2 emissj..onsfrom all sectors grow from approximately 7.0 EtC (per year) in 1985 toover 15 EtC (per year) in 2025. The energy contribution grows from about5 BtC (per year) to over 12 BtC (per year). Primary energy demand morethan doubles between 1985 and 2025 with an average growth rate of 2.1%.The per capita energy emissions in the industrialized countries increasefrom 3.1 tonnes carbon (TC) in 1985 to 4.7 TC in 2025; for the developingcountries, they rise from 0.4 TC in 1985 to 0.8 TC in 2025.

Summary

All of the above scenarios provide a conceptual basis for consideringpossible future patterns of emissions and the broad responses that mightaffect those patterns. No full assessment was made of the total economiccosts and benefits, technological feasibility, or market potential of theunderlying policy assumptions. Because of the inherent limitations inour ability to estimate future rates of population and economic growthlindividual behaviour, technological innovation, and other factors whichare crucial for determining emission rates over the course of the nextcentury, there is some uncertainty in the projections of greenhouse gasemissions. Reflecting these inherent difficulties I the IPCC's work onemissions scenarios are the best estimates at this time covering emissionsover the next century, but continued work to develop improved assumptions

and methods for scenario estimates will be useful to guide the developmentof response strategies.

19

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