世界银行-气候变化适应：证据说明了什么？（英）-2024.3_市场营销策划_2024年市场报告-3月.docx

PaUO1.nnValnsoosQ.2-qndPolicyResearchWorkingPaper10729ClimateChangeAdaptationWhatDoestheEvidenceSay?PZ'OfnValnsoosQ.2-qndJonahRexerSiddharthSharmaworldBankgroupSouthAsiaRegionOfficeoftheChiefEconomistMarch2024Poi.icyRESEARCHWorkingPaper10729AbstractAdaPtingtoclimatechangeisanincreasinglyurgentpolicypriorityinlower-andmiddle-incomecountries.Thissystematicreviewsummarizesthecurrentstateoftheliteratureonadaptationtoclimatechange,andconductsaquantitativemcta-analysisoftheeffectivenessofclimateadaptation.ThCmcta-analysisrevealsthatObSCrVCdadaptationsoffset46percentofclimatelossesonaverage,withfirmsusingmoreeffectiveadaptationstrategicsthanhouseholdsandfarmers.Thereviewidentifiesseveralkeylessons.First,purelyprivateadaptationstoclimateshockstendtobelesseffectivethanthosefrompublicinfrastructureandservices,althoughneitherbyitselfisgenerallysufficienttofullyoffsettheeffectsofclimatechange.Second,someadaptationsmayreduceclimatelossesinthepresent,butinthelong-run,households,firms,andfarmersmightbebcttcr-sencdbyreducingtheirclimateexposure.Third,theliteraturetendstofocusonadaptationbyhouseholdsandfarmers,neglectingfirms.Finally,productivitylossesfromclimateshocksmaybeoffsetifcapitalandlaborcanadjustacrosssectorsandlocations,butconstraintsonthesereallocationshavenotbeensufficientlystudied.ThispaperisaproductoftheOfficeoftheChiefEconomist,SouthAsiaRegion.ItispartofalargereffortbytheWorldBanktoprovideopenaccesstoitsresearchandmakeacontributiontodevelopmentpolicydiscussionsaroundtheworld.PolicyResearchWorkingPapersarealsopostedontheWebatTheauthorsmaybecontactedatssharmalworldbank.organdjrexerworldbank.org.TIjcPoiityRese<rcbWorkingPaperSeriesdisseminatestf)efindingofn>ork.hiprogresstoencouragetbcexcbanofideasaboutdetvfofimentissues.Anoecthfeoftheseriesisto*/tbtfindingoutquickfy,evNif'thepresentationsarelessthanfullypolished.Thepaperscanythenawtsoftbeauthorsandshouldbecited(ccorditty.Thefinding,interpretations,andconclusionsexpressedinthisp(rareentirrlyt!wse可theauthors.TheydonotnecrssarilyrrprvstrnttheviewsoftheInleniationalbankforReconstructionandDevtiopMenl/WorldBankanditsaffiliatedorganisations,orthoseoftheVlxecuihvDincforsoflbeWorldBankortheavmmentstheyrepresent.ProducedbytheResearchSupportTeamClimatechangeadaptation:Whatdoestheevidencesay?JonahRexer*1SiddharthSharma1Keywords:Climatechangeadaptation,Meta-analysis,SouthAsia,Technologyadoption,Publicgoods,Reallocation,Transfers,Diversification.JE1.codes,.Q50,Q54,Q55,Q561. IntroductionClimatechangeisleadingtohighersurfacetemperatures,acidifyingoceans,andarisingglobalmeansealevel.Theconsensusestimateisthattheaverageglobalsurfacetemperaturehasincreasedby0.85degreeCelsiussincetheindustrialrevolution,withestimatesoffutureincreaserangingfrom0.9to5.4degreesCelsiusbytheendofthiscentury(HsiangandKopp2018,IPCC2014).Withlong-termprecipitationpatternschangingincomplexways,somepartsoftheworldareexpectedtogetdrier,whileothersgetwetter(HsiangandKopp2018).Droughtsareexpectedtobecomemorecommonindrierpartsoftheworld(Collinsetal.2014).Climatechangeisalsoincreasingthefrequencyandintensityofextremeweatherevents.Forinstance,theprevalenceofintensetropicalcyclonesisexpectedtoincrease(Kossinetal.2017).Thesechangesintheearth,sclimateareprojectedtoreduceaggregateeconomicoutputbecauseoftheiradverseeffectsonagriculturalyields,industrialoutput,laborsupply,productivity,andhumancapital,amongothermechanisms(Auffhammer2018,CarletonandHsiang2016,Dell,Jones,andOlken2014,InternationalMonetaryFund2020).RecenteconometricstudiessuggestthatwarminghasasizableadverseimpactonGDP(Burke,Hsiang,andMiguel2015,Dell,Jones,andOlken2012,Hsiang2010).Basedonareviewofsuchstudies,CarletonandHsiang(2016)estimatethatfuturewarmingwillreducetheglobalGDPgrowthrateby0.28percentagepointsperyearduringthecomingcentury.SuchestimatesofaggregateGDPimpactsaresubjecttouncertaintyaboutthefuturepathofclimatechange.However,whentheeconomicimpactsofbothclimatetrends(suchasrisingtemperatures)andclimate-change-relatedextremeeventrisks(suchasmorefrequentcyclones)aretakenintoaccount,evenmoderatefutureclimatechangescenariosimplysizableeffectsonGDP(Fernando,1.iu,andMcKibbin2021).Majorstormshavesizablenegativeimpactsonsucheconomicoutcomesasper-capitaincomeandoutput(Anttila-HughesandHsiang2013,Cachon,Gallino,andOlivares2012,Nordhaus2010,Yang2008).Stormsalsodamageproductiveassets:inIndia,forexample,theaveragecyclonedestroys2.2percentofafirm'sfixedassets(Pcllietal.2023).Cyclonesanddroughtsalsoincreaseinfantmortalityandworsenotherhealthoutcomes(Anttila-HughesandHsiang2013,CurrieandRossin-Slater2013,Kudamatsu2016,Schmitt,Graham,andWhite2016).Asaresult,extremeweathereventsnotonlyreduceoutputintheshortrun,butalsoharmlong-runeconomicgrowth:a90th-percentilecycloneeventisestimatedtoreduceper-capitaincomesby7.4percenttwodecadeslater(HsiangandJina2014).Theeconomicimpactsofclimatetrends,suchasrisingtemperatu