净零目标迫使气候政策采用向后归纳法（英）

ANet-ZeroTargetCompelsaBackwardsInductionApproachtoClimatePolicy GeoffroyDolphin,MichaelPahle,DallasBurtraw,andMirjamKosch WP22-18 October2022 AbouttheAuthors GeoffroyDolphinisapostdoctoralfellowatResourcesfortheFutureandaPhDgraduatefromtheUniversityofCambridgeJudgeBusinessSchoolwhereheisanaffiliateoftheEnergyPolicyResearchGroup.Geoffroy’sresearchinterestsspanpoliticaleconomy,energy&environmentaleconomicsandclimatepolicy.Hisresearchaimstoinformthedevelopmentofclimatepolicydesignsthatarepoliticallysustainablewhilebeingenvironmentallyeffective. MichaelPahleisheadoftheworkinggroup“ClimateandEnergyPolicy”atthePotsdamInstituteforClimateImpactResearch(PIK).HeholdsaPhDineconomicsfromTUBerlin.Hisresearchfocusesonemissiontradingsystems,publicsupportforcarbonpricing,andregulatoryframeworkstoachievenet-zero.HeisPrincipleInvestigatoron“EuropeanClimateandEnergyPolicy”intheBMBFAriadneProject,Germany’slargestsocialscienceEnergiewenderesearchproject. DallasBurtrawistheDariusGaskinsSeniorFellowatResourcesfortheFuture.Burtrawhasworkedtopromoteefficientcontrolofairpollutionandwrittenextensivelyonelectricityindustryregulationandenvironmentaloutcomes.Burtraw’scurrentresearchincludesanalysisofthedistributionalandregionalconsequencesofclimatepolicy,theevolutionofelectricitymarketsincludingrenewableintegration,andtheinteractionofclimatepolicywithelectricitymarkets. MirjamKoschisanenthusiasticenvironmentalscientistandcompletedherdoctorateineconomicsatETHZurichonclimatepolicyintheelectricitysector.Aspartofherdoctoralthesis,sheempiricallyanalyzedtheimpactofrenewableenergysubsidiesandcarbonpricing.Currently,sheisworkingontheexpansionoftheEuropeanemissionstradingsystemandinvestigatingtheinterplayofdifferentpolicyinstrumentsaswellastheimpactofclimatepolicyonelectricityprices. Acknowledgments WegratefullyacknowledgefinancialsupportfromtheFederalMinistryofEducationandResearchofGermanyintheAriadneproject(03SFK5S0)andResourcesfortheFutureComprehensiveClimatePoliciesProgram.WeareindebtedtoLawrenceGoulderandGregoryNemet,aswellasparticipantstotheRFFSeminarSeries,forhelpfulcommentsonearlierversionsofthispaper. AboutRFF ResourcesfortheFuture(RFF)isanindependent,nonprofitresearchinstitutioninWashington,DC.Itsmissionistoimproveenvironmental,energy,andnaturalresourcedecisionsthroughimpartialeconomicresearchandpolicyengagement.RFFiscommittedtobeingthemostwidelytrustedsourceofresearchinsightsandpolicysolutionsleadingtoahealthyenvironmentandathrivingeconomy. Workingpapersareresearchmaterialscirculatedbytheirauthorsforpurposesofinformationanddiscussion.Theyhavenotnecessarilyundergoneformalpeerreview.TheviewsexpressedherearethoseoftheindividualauthorsandmaydifferfromthoseofotherRFFexperts,itsofficers,oritsdirectors. SharingOurWork OurworkisavailableforsharingandadaptationunderanAttribution-NonCommercial-NoDerivatives4.0International(CCBY-NC-ND4.0)license.Youcancopyandredistributeourmaterialinanymediumorformat;youmustgiveappropriatecredit,providealinktothelicense,andindicateifchangesweremade,andyoumaynotapplyadditionalrestrictions.Youmaydosoinanyreasonablemanner,butnotinanywaythatsuggeststhelicensorendorsesyouoryouruse.Youmaynotusethematerialforcommercialpurposes.Ifyouremix,transform,orbuilduponthematerial,youmaynotdistributethemodifiedmaterial.Formoreinformation,visithttps://creativecommons.org/licenses/by-nc-nd/4.0/. Abstract Jurisdictionsaroundtheworldincreasinglyaffirmtheircontributionstothe2015ParisAgreementbypledgingnetzerotargets.Wearguethatdeliveringonanet-zerotargetcompelsabackwardinductionapproachtoclimatepolicy,whichdiffersfromtheprevailingapproachbystipulatingthattheobjectivefordesigningpolicypathwaysmustchangefromminimizingthecostofthepolicytomaximizingitscredibility.Ourargumentrestsonthepremisethatprivateinvestmentsplayakeyrolefornetzero,andtoalignthemwithnetzero,gettingexpectationsrightismorerelevantthangettingthepricesright.Backwardinductioncompelsadynamicallyconsistentpathwaythatcanovercometheproblemthatemittersmayexpecttherulesandtargetsofclimatepolicyasopenforconstantpoliticalrenegotiation.Wefurthermoresketchthemainelementsforaregulatorystrategytoputthisapproachintoactionthatbuildsoninstillingcommitment. Contents 1.Introduction1 2.Investors’ExpectationsandClimatePolicyCredibility3 3.TheMainPolicyRuleforNetZero:GettingExpectationsRight5 4.ImplementingBackwardInductioninaRegulatoryStrategy9 5.Conclusion12 6.References13 1.Introduction Jurisdictionsaroundtheworldincreasinglyaffirmtheircontributionstothe2015ParisAgreementbypledgingnetzeroemissiontargets.Specifically,governmentshaveissuedstatements(Japan),submittedlegislativeproposals(Canada,EuropeanUnion),orenactedlaws(UnitedKingdom,NewZealand)toreachnetzeroemissionsbymidcentury(Haleetal.2021),assuggestedbytheIPCCspecialreportontheimpactsofglobalwarmingof1.5Cabovepre-industriallevels(IPCC,2018).Thisgoalisunderpinnedbythenotionthatachievingaspecificwarmingobjectiverequiresacommitmenttoasetcarbonbudget(Drouetetal.2021).Yetnet-zerotargetslimitpolicymakers’abilitytoaltertheemissionsreductiont