Expert credibility in climate change

环境保护,气候变化

Expertcredibilityinclimatechange

WilliamR.L.Anderegga,1,JamesW.Prallb,JacobHaroldc,andStephenH.Schneidera,d,1

DepartmentofBiology,StanfordUniversity,Stanford,CA94305;bElectricalandComputerEngineering,UniversityofToronto,Toronto,ON,CanadaM5S3G4;cWilliamandFloraHewlettFoundation,PaloAlto,CA94025;anddWoodsInstitutefortheEnvironment,StanfordUniversity,Stanford,CA94305ContributedbyStephenH.Schneider,April9,2010(sentforreviewDecember22,2009)

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Althoughpreliminaryestimatesfrompublishedliteratureandexpertsurveyssuggeststrikingagreementamongclimatescientistsonthetenetsofanthropogenicclimatechange(ACC),theAmericanpublicexpressessubstantialdoubtaboutboththeanthropogeniccauseandthelevelofscienti cagreementunderpinningACC.Abroadanalysisoftheclimatescientistcommunityitself,thedistributionofcredibilityofdissentingresearchersrelativetoagreeingresearchers,andthelevelofagreementamongtopclimateexpertshasnotbeenconductedandwouldinformfutureACCdiscussions.Here,weuseanextensivedatasetof1,372climateresearchersandtheirpublicationandcitationdatatoshowthat(i)97–98%oftheclimateresearchersmostactivelypublishinginthe eldsurveyedheresup-portthetenetsofACCoutlinedbytheIntergovernmentalPanelonClimateChange,and(ii)therelativeclimateexpertiseandscienti cprominenceoftheresearchersunconvincedofACCaresubstantiallybelowthatoftheconvincedresearchers.

citationanalysesclimatedenieranalysisscienti cprominence

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reliminaryreviewsofscienti cliteratureandsurveysofcli-matescientistsindicatestrikingagreementwiththeprimaryconclusionsoftheIntergovernmentalPanelonClimateChange(IPCC):anthropogenicgreenhousegaseshavebeenresponsiblefor“most”ofthe“unequivocal”warmingoftheEarth’saverageglobaltemperatureoverthesecondhalfofthe20thcentury(1–3).Nonetheless,substantialandgrowingpublicdoubtremainsabouttheanthropogeniccauseandscienti cagreementabouttheroleofanthropogenicgreenhousegasesinclimatechange(4,5).Avocalminorityofresearchersandothercriticscontesttheconclusionsofthemainstreamscienti cassessment,frequentlycitinglargenumbersofscientistswhomtheybelievesupporttheirclaims(6–8).Thisgroup,oftentermedclimatechangeskeptics,contrarians,ordeniers,hasreceivedlargeamountsofmediaattentionandwieldssigni cantin uenceinthesocietaldebateaboutclimatechangeimpactsandpolicy(7,9–14).

Anextensiveliteratureexamineswhatconstitutesexpertiseorcredibilityintechnicalandpolicy-relevantscienti cresearch(15).Thoughouraimisnottoexpanduponthatliteraturehere,wewishtodrawuponseveralimportantobservationsfromthisliteratureinexaminingexpertcredibilityinclimatechange.First,thoughthedegree credibleuencesofremainsincontextual,determiningpolitical,debated,whomanycountsepistemological,scholarsasacknowledgeanexpertandandculturalin-theneedwhotoisidentifycredibleexpertsandaccountforexpertopinionintech-nical(e.g.,science-based)decision-making(15–19).Furthermore,delineatingexpertiseandtherelativecredibilityofclaimsiscriti-cal,especiallyinareaswhereitmaybedif cultforthemajorityofdecision-makersandthelaypublictoevaluatethefullcomplexitiesofatechnicalissue(12,15).Ultimately,however,societaldecisionsregardingresponsetoACCmustnecessarilyincludeinputfrommanydiverseandnonexpertstakeholders.

Becausethetimelineofdecision-makingisoftenmorerapidthanscienti cconsensus,examiningthelandscapeofexpertopinioncangreatlyinformsuchdecision-making(15,19).Here,weexamineametricofclimate-speci cexpertiseandametricofoverallsci-enti cprominenceastwodimensionsofexpertcredibilityintwogroupsofresearchers.Weprovideabroadassessmentoftherel-ativecredibilityofresearchersconvincedbytheevidence(CE)ofACCandthoseunconvincedbytheevidence(UE)ofACC.OurconsiderationofUEresearchersdiffersfrompreviousworkon

http:///cgi/doi/10.1073/pnas.1003187107

climatechangeskepticsandcontrariansinthatweprimarilyfocusonresearchersthathavepublishedextensivelyintheclimate eld,althoughweconsiderallskeptics/contrariansthathavesignedpro-minentstatementsconcerningACC(6–8).SuchexpertanalysiscanilluminatepublicandpolicydiscussionsaboutACCandtheextentofconsensusintheexpertscienti ccommunity.

Wecompiledadatabaseof1,372climateresearchersbasedonauthorshipofscienti cassessmentreportsandmembershiponmultisignatorystatementsaboutACC(SIMaterialsandMethods).Wetalliedthenumberofclimate-relevantpublicationsauthoredorcoauthoredbyeachresearcher(de nedhereasexpertise)andcountedthenumberofcitationsforeachoftheresearcher’sfourhighest-citedpapers(de nedhereasprominence)usingGoogleScholar.Wethenimposedanaprioricriterionthataresearchermusthaveauthoredaminimumof20climatepublicationstobeconsideredaclimateresearcher,thusreducingthedatabaseto908researchers.Varyingthisminimumpublicationcutoffdidnotma-teriallyalterresults(MaterialsandMethods).

Werankedresearchersbasedonthetotalnumberofclimatepublicationsauthored.Thoughourcompiledresearcherlistisnotcomprehensivenordesignedtoberepresentativeoftheentirecli-matesciencecommunity,wehavedrawnresearchersfromthemosthigh-pro lereportsandpublicstatementsaboutACC.Therefore,wehavelikelycompiledthestrongestandmostcredentialedre-searchersinCEandUEgroups.Citationandpublicationanalysesmustbetreatedwithcautionininferringscienti ccredibility,butwesuggestthatourmethodsandourexpertiseandprominencecriteriaprovideconservative,robust,andrelevantindicatorsofrelativecredibilityofCEandUEgroupsofclimateresearchers(MaterialsandMethods).

ResultsandDiscussion

TheUEgroupcomprisesonly2%ofthetop50climateresearchersasrankedbyexpertise(numberofclimatepublications),3%ofresearchersofthetop100,and2.5%ofthetop200,excludingresearcherspresentinbothgroups(MaterialsandMethods).Thisresultcloselyagreeswithexpertsurveys,indicatingthat≈97%ofself-identi edactivelypublishingclimatescientistsagreewiththetenetsofACC(2).Furthermore,this ndingcomplementsdirectpollingoftheclimateresearchercommunity,whichyieldsquali-tativeandself-reportedresearcherexpertise(2).Our ndingscapturetheaddeddimensionofthed …… 此处隐藏：18698字，全部文档内容请下载后查看。喜欢就下载吧 ……