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ISBN: 978-92-807-3890-2

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©2021UnitedNationsEnvironmentProgrammeISBN:978-92-807-3890-2Jobnumber:DEW/2388/NAThispublicationmaybereproducedinwholeorinpartandinanyformforeducationalornon-profitserviceswithoutspecialpermissionfromthecopyrightholder,providedacknowledgementofthesourceismade.TheUnitedNationsEnvironmentProgrammewouldappreciatereceivingacopyofanypublicationthatusesthispublicationasasource.NouseofthispublicationmaybemadeforresaleoranyothercommercialpurposewhatsoeverwithoutpriorpermissioninwritingfromtheSecretariatoftheUnitedNations.Applicationsforsuchpermission,withastatementofthepurposeandextentofthereproduction,shouldbeaddressedtotheDirector,CommunicationDivision,UnitedNationsEnvironmentProgramme,P.O.Box30552,Nairobi00100,Kenya.DisclaimersThedesignationsemployedandthepresentationofthematerialinthispublicationdonotimplytheexpressionofanyopinionwhatsoeveronthepartoftheSecretariatoftheUnitedNationsconcerningthelegalstatusofanycountry,territoryorcityoritsauthorities,orconcerningthedelimitationofitsfrontiersorboundaries.Someillustrationsorgraphicsappearinginthispublicationmayhavebeenadaptedfromcontentpublishedbythirdpartiestoillustratetheauthors’owninterpretationsofthekeymessagesemergingfromsuchthird-partyillustrationsorgraphics.Insuchcases,thematerialinthispublicationdoesnotimplytheexpressionofanyopinionwhatsoeveronthepartofUnitedNationsEnvironmentProgrammeconcerningthesourcematerialsusedasabasisforsuchgraphicsorillustrations.MentionofacommercialcompanyorproductinthisdocumentdoesnotimplyendorsementbytheUnitedNationsEnvironmentProgrammeortheauthors.Theuseofinformationfromthisdocumentforpublicityoradvertisingisnotpermitted.Trademarknamesandsymbolsareusedinaneditorialfashionwithnointentiononinfringementoftrademarkorcopyrightlaws.TheviewsexpressedinthispublicationarethoseoftheauthorsanddonotnecessarilyreflecttheviewsoftheUnitedNationsEnvironmentProgramme.Weregretanyerrorsoromissionsthatmayhavebeenunwittinglymade.©Maps,photosandillustrationsasspecifiedSuggestedcitationUnitedNationsEnvironmentProgramme(2021).EmissionsGapReport2021:TheHeatIsOn–AWorldofClimatePromisesNotYetDelivered.NairobiProductionUnitedNationsEnvironmentProgramme(UNEP)andUNEPDTUPartnership.https://www.unep.org/emissions-gap-report-2021Supportedby:UNEPpromotesenvironmentallysoundpracticesgloballyandinitsownactivities.OurdistributionpolicyaimstoreduceUNEP'scarbonfootprint.TheHeatIsOnAworldofclimatepromisesnotyetdeliveredEmissionsGapReport2021VEmissionsGapReport2021:TheHeatIsOnAcknowledgementsAcknowledgementsTheUnitedNationsEnvironmentProgramme(UNEP)wouldliketothankthemembersofthesteeringcommittee,theleadandcontributingauthors,reviewersandthesecretariatfortheircontributiontothepreparationofthisassessmentreport.Authorsandreviewershavecontributedtothereportintheirindividualcapacities.Theiraffiliationsareonlymentionedforidentificationpurposes.SteeringcommitteeJulianeBerger(GermanEnvironmentAgency),JohnChristensen(CONCITO[Denmark’sclimatethinktank]),NavrozK.Dubash(CentreforPolicyResearch,India),JamesFoster(UKDepartmentforBusiness,EnergyandIndustrialStrategy),SamuelKarslake(UKDepartmentforBusiness,EnergyandIndustrialStrategy),MikeKeoghan(UKDepartmentforBusiness,EnergyandIndustrialStrategy),GerdLeipold(ClimateTransparency),JianLiu(UNEP),SimonMaxwell(independent),SurabiMenon(ClimateWorksFoundation),BertMetz(EuropeanClimateFoundation),KatiaSimeonova(independent),OksanaTarasova(WorldMeteorologicalOrganization)andXuehongWang(UnitedNationsFrameworkConventiononClimateChange[UNFCCC])AuthorsChapter1Authors:AnneOlhoff(UNEPDTUPartnership,Denmark),JohnChristensen(CONCITO[Denmark’sclimatethinktank])Chapter2Leadauthors:TakeshiKuramochi(NewClimateInstitute,Germany),MicheldenElzen(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),TarynFransen(WorldResourcesInstitute,USA),GlenPeters(CenterforInternationalClimateResearch[CICERO],Norway)Contributingauthors:AndrzejAncygier(ClimateAnalytics,Germany),AyşeCerenSarı(SHURA,Turkey),AnnaChapman(ClimateAnalytics,Australia),MonicaCrippa(JointResearchCentre[JRC],Italy),MengpinGe(WorldResourcesInstitute,USA),JohannesGütschow(PotsdamInstituteforClimateImpactResearch,Germany),MarianaGutierrez(IniciativaClimatica,Mexico),DiegoGuizzardi(JRC,Italy),GaheeHan(SolutionsForOurClimate,RepublicofKorea),NiklasHöhne(NewClimateInstitue,Germany),LouiseJeffery(NewClimateInstitute,Germany),KimonKeramidas(JRC,Spain),CarolineLee(CanadianInstituteforClimateChoices,Canada),EnriqueMaurtuaKonstantinidis(FundaciónAmbienteyRecursosNaturales[FARN],Argentina),VictorMaxwell(ClimateAnalytics,Australia),MalteMeinshausen(UniversityofMelbourne,Australia),MarilenaMuntean(JRC,Italy),LeonardoNascimento(NewClimateInstitute,Germany),JosOlivier(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),MarkRoelfsema(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),EfisioSolazzo(JRC,Italy),HajimeTakizawa(InstituteforGlobalEnvironmentalStrategies,Japan),KentaroTamura(InstituteforGlobalEnvironmentalStrategies,Japan),HeleenvanSoest(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),JorgeVillareal(IniciativaClimatica,Mexico),SachiVohra(TheEnergyandResourcesInstitute[TERI],India),LisaWijayani(InstituteforEssentialServicesReform[IESR],Indonesia),WilliamWills(EosEstratégia&Sustentabilidade,Brazil),RyanWilson(ClimateAnalytics,Germany)Chapter3Leadauthors:JoeriRogelj(ImperialCollegeLondon,UK;InternationalInstituteforAppliedSystemsAnalysis[IIASA],Austria),StephenM.Smith(OxfordUniversity,UK),ShaYu(PacificNorthwestNationalLaboratory[PNNL],USA)Contributingauthors:JiyongEom(KoreaAdvancedInstituteofScienceandTechnology[KAIST],RepublicofKorea),TarynFransen(WorldResourcesInstitute,USA),ClaireFyson(ClimateAnalytics,Germany),ThomasHale(OxfordUniversity,UK),FredericHans(NewClimateInstitute,Germany),JohnLang(Energy&ClimateIntelligenceUnit,UK),SilkeMooldijk(NewClimateInstitute,Germany),KatieRoss(WorldResourcesInstitute,USA)Chapter4Leadauthors:MicheldenElzen(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),JoanaPortugal-Pereira(GraduateSchoolofEngineering[COPPE],UniversidadeFederaldoRiodeJaneiro,Brazil),JoeriRogelj(GranthamInstitute,ImperialCollegeLondon,UK;InternationalInstituteforAppliedSystemsAnalysis[IIASA],Austria)Contributingauthors:IoannisDafnomilis(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),JohannesGütschow(PotsdamInstituteforClimateImpactResearch,Germany),KimonKeramidas(JointResearchCentre[JRC],Spain),RobinLamboll(ImperialCollegeLondon,UK),JaredLewis(UniversityofMelbourne,Australia),MalteMeinshausen(UniversityofMelbourne,Australia),ZebedeeNicholls(UniversityofMelbourne,Australia)Chapter5Leadauthors:BrianO’Callaghan(UniversityofOxford,UK;HarvardUniversity,USA),Jean-PaulAdam(UnitedNationsEconomicCommissionforAfrica[UNECA],Ethiopia)Contributingauthors:BartholomewArmah(UNECA,Ethiopia),JeanPaulBoketsuBofili(UNECA,Ethiopia),HopestoneKayiskaChavula(UNECA,Ethiopia),FredericHans(NewClimateInstitute,Germany),AndrewPrag(OrganisationforEconomicCo-operationandDevelopment[OECD],France),DavidTritsch(UniversityofOxford,UK)Chapter6Leadauthors:DrewShindell(DukeUniversity,USA),MarielleSaunois(UniversitédeVersaillesSaint-Quentin[UVSQ],LaboratoiredesSciencesduClimatetdel'Environnement[LSCE],France)VIEmissionsGapReport2021:TheHeatIsOnContributingauthors:DominikBrunner(SwissFederalLaboratoriesforMaterialsScienceandTechnology[EMPA],Switzerland),LenaHöglund-Isaksson(InternationalInstituteforAppliedSystemsAnalysis[IIASA],Austria),KevinKarl(FoodandAgricultureOrganizationoftheUnitedNations[FAO],Italy),EuanNisbet(RoyalHolloway,UniversityofLondon,UK),StefanSchwietzke(EnvironmentalDefenseFund[EDF],USA),FrancescoTubiello(FAO,Italy)Chapter7Leadauthors:ShaYu(PacificNorthwestNationalLaboratory[PNNL],USA),MaoshengDuan(TsinghuaUniversity,China),JaeEdmonds(PNNL,USA)Contributingauthors:KatherineCalvin(PNNL,USA),StefanoDeClara(InternationalCarbonActionPartnership[ICAP],Germany),DirkForrister(InternationalEmissionsTradingAssociation[IETA],Switzerland),StephanieLaHozTheuer(adelphi,Germany),LucaLoRe(InternationalEnergyAgency[IEA],France),RubenLubowski(EnvironmentalDefenseFund[EDF],USA),AxelMichaelowa(PerspectivesandUniversityofZurich,Switzerland),ClaytonMunnings(UniversityofCalifornia,Berkeley,USA),KarenHolmOlsen(UNEPDTUPartnership,Denmark),MandyRambharos(Eskom,SouthAfrica),ChandraShekharSinha(WorldBank,USA),DetlefvanVuuren(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands)ReviewersJesicaAndrews(UNEPFinanceInitiative),JulianeBerger(GermanEnvironmentAgency),ThomasBernheim(EuropeanCommissionDirectorate-GeneralforClimateAction),NathanBorgford-Parnell(ScientificAdvisoryPanelandClimateandCleanAirCoalition[CCAC]),DerikBroekhoff(StockholmEnvironmentInstitute),LouiseBurrows(UKDepartmentforBusiness,EnergyandIndustrialStrategy),ManfrediCaltagirone(UNEP),CyrilCassisa(BHP),OliverChaplin(UKDepartmentforBusiness,EnergyandIndustrialStrategy),JohnChristensen(CONCITO[Denmark’sclimatethinktank]),LauraCozzi(InternationalEnergyAgency[IEA]),NavrozK.Dubash(CentreforPolicyResearch,India),VirenderK.Duggal(AsianDevelopmentBank),JamesDyke(UniversityofExeter),VeronikaElgart(FederalOfficefortheEnvironmentoftheSwissConfederation),KateErvine(SaintMary’sUniversity),KaiRemcoFisher(UNEPFinanceInitiative),ShinichiroFujimori(KyotoUniversity),JamesFoster(UKDepartmentforBusiness,EnergyandIndustrialStrategy),OliverGeden(GermanInstituteforInternationalandSecurityAffairs),MuhammadArifGoheer(GlobalChangeImpactStudiesCentre),MartinHession(EuropeanCommissionDirectorate-GeneralforClimateAction),AndreaHinwood(UNEP),AndrewHoward(KoruClimate),JasonJabbour(UNEP),YasukoKameyama(NationalInstituteforEnvironmentalStudies,Japan),MaartenKappelle(UNEP),KarstenKarschunke(GermanEnvironmentAgency),SamuelKarslake(UKDepartmentforBusiness,EnergyandIndustrialStrategy),MikeKeoghan(UKDepartmentforBusiness,EnergyandIndustrialStrategy),KatreKets(EuropeanCommissionDirectorate-GeneralforClimateAction),GerardusKlaassen(EuropeanCommissionDirectorate-GeneralforClimateAction),GerdLeipold(ClimateTransparency),ThomasLiesch(Allianz),JianLiu(UNEP),MichaelLuker(UKDepartmentforBusiness,EnergyandIndustrialStrategy),JamesMabbutt(UKDepartmentforBusiness,EnergyandIndustrialStrategy),KathleenMcAfee(SanFranciscoStateUniversity),SimonMaxwell(independent),SurabiMenon(ClimateWorksFoundation),BertMetz(EuropeanClimateFoundation),BrendanMoore(UniversityofEastAnglia),SusanMutebi-Richards(UNEP),NickNuttall(WeDon’tHaveTime),MilesPerry(EuropeanCommissionDirectorate-GeneralforClimateAction),FrederikPischke(GermanEnvironmentAgency),RulaQalyoubi(UNEP),MarkRadka(UNEP),AkkihebbalRamaiahRavishankara(ColoradoStateUniversity),YannRobiouduPont(Climate&EnergyCollege),KatieRoss(WorldResourcesInstitute),ChristianSchoder(WorldBank),HimanshuSharma(UNEP),KatiaSimeonova(independent),ThomasSpencer(IEA),JamalSrouji(WorldResourcesInstitute),OksanaTarasova(WorldMeteorologicalOrganization),JacopoTattini(IEA),MelvinvanVelthoven(EuropeanCommissionDirectorate-GeneralforClimateAction),XuehongWang(UnitedNationsFrameworkConventiononClimateChange[UNFCCC]),CarstenWarnecke(NewClimateInstitute),BobWatson(EastAngliaUniversity),DanielWetzel(IEA),ZhaoXiusheng(TsinghuaUniversity),JinhuaZhang(UNEP),YuqiangZhang(DukeUniversity),EdoardoZandri(UNEP),CarolineZimm(InternationalInstituteforAppliedSystemsAnalysis[IIASA])ChiefscientificeditorsAnneOlhoff(UNEPDTUPartnership),JohnChristensen(CONCITO[Denmark’sclimatethinktank])EditorialsupportJuliaRochaRomero(UNEPDTUPartnership)Secretariat,productionandcoordinationAnneOlhoff(UNEPDTUPartnership),JuliaRochaRomero(UNEPDTUPartnership),KaisaUusimaa(UNEP),MaartenKappelle(UNEP),EdoardoZandri(UNEP)MediaandlaunchsupportDanielCooney(UNEP),DavidCole(UNEP),KatieElles(UNEP),FlorianFussstetter(UNEP),MariaVittoriaGalassi(UNEP),NancyGroves(UNEP),RuneKier(UNEP),ViolaKup(UNEP),NicolienSchoneveld-deLange(UNEP),MichaelLogan(UNEP),BeverleyMcDonald(UNEP),PoojaMunshi(UNEP),KeishamazaRukikaire(UNEP),LailaSaada(UNEP),ReaganSirengo(UNEP),NehaSud(UNEP)andseveralothermembersoftheUNEPCommunicationDivision,MetteAnnelieRasmussen(UNEPDTUPartnership),LasseHemmingsen(UNEPDTUPartnership),MonnaHammershøyBlegvad(UNEPDTUPartnership)VIIEmissionsGapReport2021:TheHeatIsOnDesignandlayoutJoseph&Sebastian(cover),StrategicAgenda(figuresandlayout)TranslationsoftheexecutivesummaryandlanguageeditingStrategicAgendaThanksalsoto:MagdaBiesiada(UNEP),AngelineDjampou(UNEP),JohanFalk(ExponentialRoadmapInitiative),OwenGaffney(StockholmResilienceCentre),FrankGeels(UniversityofManchester),DanyGhafari(UNEP),NiklasHagelberg(UNEP),SuzanaKahnRibeiro(UniversidaeFederaldoRiodeJaneiro),YawoKonko(UNEP),KellyLevin(BezosEarthFund),PazLopez-Rey(UNEP),OmarMasera(UniversidadNacionalAutónomadeMéxico),SofíaMéndezMora(UNEP),JaneMuriithi(UNEP),EkaterinaPoleshchuk(UNEP),JoyashreeRoy(AsianInstituteofTechnology),SybrigSmit(NewClimateInstitute),NanditaSurendran(UNEP),YingWang(UNEP)UNEPwouldliketothanktheClimateWorksFoundation,theDanishMinistryofForeignAffairs,theDutchMinistryofEconomicAffairsandClimatePolicy,theGermanFederalMinistryfortheEnvironment,NatureConservationandNuclearSafety(BMU)anditsInternationalClimateInitiative(IKI),theNordicWorkingGroupforClimateandAir(NKL)oftheNordicCouncilofMinistersandtheSwedishInternationalDevelopmentCooperationAuthority(SIDA)forsupportingtheworkoftheEmissionsGapReport2021.VIIIEmissionsGapReport2021:TheHeatIsOnIXEmissionsGapReport2021:TheHeatIsOnContentsAcknowledgementsVGlossaryXIForewordXVChapter1Introduction11.1ContextoftheEmissionsGapReport202111.2Focus,approachandstructureofthereport1Chapter2Trendsinglobalemissions,newpledgesfor2030andG20statusandoutlook32.1Introduction32.2Currentglobalemissions:statusandtrends42.3TrendsandimplicationsoftheneworupdatedNDCsandotherannouncedmitigationpledgesfor203062.4AssessmentofG20members’progresstowardsNDCsandmitigationpledgesfor203012Chapter3Net-zeroemissionstargets183.1Introduction183.2Thescienceofnet-zeroemissionstargets183.3Net-zeroatthenationallevel223.4Trackingnationalnet-zerotargetsglobally243.5Acloserlookatnet-zerotargetsintheG2025Chapter4Theemissionsgap294.1Introduction294.2Scenariosconsideredforthe2030gapassessment294.3Theemissionsgap324.4Temperatureimplicationsoftheemissionsgap36Chapter5AreCOVID-19fiscalrecoverymeasuresbridgingorextendingtheemissionsgap?385.1Introduction385.2HowcouldCOVID-19-relatedpublicspendingbridgetheemissionsgap?395.3Whatarethecharacteristicsoffiscalrescueandrecoveryspendingtodateandhowmaytheyimpacttheemissionsgap?415.4Dolower-incomenationsfacegreaterbarriersforlow-carbonrecoveryspending?Ifso,whatcanbedone?43Chapter6Theroleofanthropogenicmethaneemissionsinbridgingtheemissionsgap476.1Introduction476.2Optimizingmethaneemissionreductions486.3Short-andlong-termmitigationpotentials496.4Linkbetweenmethanemitigationandpathstonet-zeroCO2526.5MethanemitigationinthefirstNDCs526.6Measurement-basedverificationofuncertainemissionreporting54Chapter7Theroleofmarketmechanismsinbridgingtheemissionsgap567.1Introduction:Theroleofcarbonmarketsandcurrentstatus567.2ThepotentialroleofinternationalcarbonmarketsundertheParisAgreement:near-termversusnet-zeroimplications587.3Usingmarketmechanismsunderarticle6617.4Thewayforward62References63XEmissionsGapReport2021:TheHeatIsOnXIEmissionsGapReport2021:TheHeatIsOnGlossaryGlossaryThisglossaryiscompiledaccordingtotheLeadAuthorsoftheReportdrawingonglossariesandotherresourcesavailableonthewebsitesofthefollowingorganizations,networksandprojects:IntergovernmentalPanelonClimateChange,UnitedNationsEnvironmentProgramme,UnitedNationsFrameworkConventiononClimateChangeandWorldResourcesInstitute.Anthropogenicmethane:Methaneemissionsderivedfromhumanactivities.Anthropogenicemissionsourcesincludecoalmining,agriculturalpractices,wastewatertreatment,certainindustrialprocessesandoilandgassystems,amongothers.Baseline/reference:Thestateagainstwhichchangeismeasured.Inthecontextofclimatechangetransformationpathways,theterm‘baselinescenarios’referstoscenariosthatarebasedontheassumptionthatnomitigationpoliciesormeasureswillbeimplementedbeyondthosethatarealreadyinforceand/orarelegislatedorplannedtobeadopted.Baselinescenariosarenotintendedtobepredictionsofthefuture,butrathercounterfactualconstructionsthatcanservetohighlightthelevelofemissionsthatwouldoccurwithoutfurtherpolicyeffort.Typically,baselinescenariosarecomparedtomitigationscenariosthatareconstructedtomeetdifferentgoalsforgreenhousegasemissions,atmosphericconcentrationsortemperaturechange.Theterm‘baselinescenario’isusedinterchangeablywith‘referencescenario’and‘nopolicyscenario’Inmuchoftheliterature,thetermisalsosynonymouswiththeterm‘businessasusual(BAU)scenario’,althoughtheterm‘BAU’hasfallenoutoffavourbecausetheideaof‘businessasusual’incentury-longsocioeconomicprojectionsishardtofathom.Carbonborderadjustmentmechanisms:Mechanismsthatacttoequalizethepriceofcarbonbetweendomesticproductsandimportstoeliminatefinancialincentivesinordertorelocateproductionoutsideofregionswithstrongclimatecontrols.Carbondioxideemissionbudget(orcarbonbudget):Foragiventemperatureriselimit,forexamplea1.5°Cor2°Clong-termlimit,thecorrespondingcarbonbudgetreflectsthetotalamountofcarbonemissionsthatcanbeemittedfortemperaturestostaybelowthatlimit.Stateddifferently,acarbonbudgetistheareaunderacarbondioxide(CO2)emissiontrajectorythatsatisfiesassumptionsaboutlimitsoncumulativeemissionsestimatedtoavoidacertainlevelofglobalmeansurfacetemperaturerise.Carbondioxideequivalent(CO2e):Awaytoplaceemissionsofvariousradiativeforcingagentsonacommonfootingbyaccountingfortheireffectonclimate.Itdescribes,foragivenmixtureandamountofgreenhousegases,theamountofCO2thatwouldhavethesameglobalwarmingability,whenmeasuredoveraspecifiedtimeperiod.Forthepurposeofthisreport,greenhousegasemissions(unlessotherwisespecified)arethesumofthebasketofgreenhousegaseslistedinAnnexAtotheKyotoProtocol,expressedasCO2eassuminga100-yearglobalwarmingpotential.Carbonmarkets:Atermforacarbontradingsystemthroughwhichcountriesmaybuyorsellunitsofgreenhousegasemissionsinanefforttomeettheirnationallimitsonemissions,eitherundertheKyotoProtocolorotheragreements,suchasthatamongmemberstatesoftheEuropeanUnion.ThetermcomesfromthefactthatCO2isthepredominantgreenhousegas,andothergasesaremeasuredinunitscalledcarbondioxideequivalent.Carbonneutrality:Thisisachievedwhenanactor’snetcontributiontoglobalCO2emissionsiszero.AnyCO2emissionsattributabletoanactor’sactivitiesarefullycompensatedbyCO2reductionsorremovalsexclusivelyclaimedbytheactor,irrespectiveofthetimeperiodortherelativemagnitudeofemissionsandremovalsinvolved.Carbonoffset:SeeOffset.Carbonprice:ThepriceforavoidedorreleasedCO2orCO2eemissions.Thismayrefertotherateofacarbontaxorthepriceofemissionpermits.Inmanymodelsthatareusedtoassesstheeconomiccostsofmitigation,carbonpricesareusedasaproxytorepresentthelevelofeffortinmitigationpolicies.Cleandevelopmentmechanism(CDM):AmechanismundertheKyotoProtocol,thepurposeofwhich,inaccordancewitharticle12oftheProtocol,istoassistnon-AnnexIpartiesinachievingsustainabledevelopmentandincontributingtotheultimateobjectiveoftheUnitedNationsFrameworkConventiononClimateChange,andtoassistAnnexIpartiesinachievingcompliancewiththeirquantifiedemissionsXIIEmissionsGapReport2021:TheHeatIsOnlimitationandreductioncommitmentsunderarticle3oftheProtocol.Conditionalnationallydeterminedcontribution(NDC):AnNDCproposedbysomecountriesthatarecontingentonarangeofpossibleconditions,suchastheabilityofnationallegislaturestoenactthenecessarylaws,ambitiousactionfromothercountries,realizationoffinanceandtechnicalsupport,orotherfactors.ConferenceoftheParties(COP):ThesupremebodyoftheUnitedNationsFrameworkConventiononClimateChange.ItcurrentlymeetsonceayeartoreviewtheConvention’sprogress.Doublecounting:Doublecountinginvolvestwocountriestakingcreditforthesameemissionsreductions,therebygivingtheimpressionthattheworldhasreducedemissionsmorethanitactuallyhas.Forexample,emissionsreductioncreditsfromonecountrymightbesoldtoanothercountry,butthereductionsmaystillbecountedtowardstheachievementoftheNDCofthecountrywherethecreditsoriginated.Emissionpathway:Thetrajectoryofannualgreenhousegasemissionsovertime.Emissionstrading:OneofthethreeKyotomechanisms,bywhichanAnnexIpartymaytransferKyotoProtocolunitsto,oracquireunitsfrom,anotherAnnexIparty.AnAnnexIpartymustmeetspecificeligibilityrequirementstoparticipateinemissionstrading.EUEmissionsTradingSystem(ETS):TheEUETSisatradingsystemforcarbonemissionsandthefirstinternationalemissionstradingsystemintheworld.TheEUETScoversthefollowingsectorsandgases:electricityandheatgeneration,energy-intensiveindustrysectors(includingoilrefineries,steelworksandproductionofiron,aluminium,metals,cement,lime,glass,ceramics,pulp,paper,cardboard,acidsandbulkorganicchemicals,commercialaviationwithintheEuropeanEconomicArea),nitrousoxidefromproductionofnitric,adipicandglyoxylicacidsandglyoxal,andperfluorocarbonsfromproductionofaluminium.Globalwarmingpotential:Anindexrepresentingthecombinedeffectofthedifferingtimesgreenhousegasesremainintheatmosphereandtheirrelativeeffectivenessinabsorbingoutgoinginfraredradiation.Greenhousegases:Theatmosphericgasesresponsibleforcausingglobalwarmingandclimaticchange.Themajorgreenhousegasesarecarbondioxide(CO2),methane(CH4)andnitrousoxide(N2O).Lessprevalent,butverypowerful,GHGsarehydrofluorocarbons(HFCs),perfluorocarbons(PFCs)andsulfurhexafluoride(SF6).Greenhousegasremoval:Withdrawalofagreenhousegasand/oraprecursorfromtheatmospherebyasink.Integratedassessmentmodels:Modelsthatseektocombineknowledgefrommultipledisciplinesintheformofequationsand/oralgorithmsinordertoexplorecomplexenvironmentalproblems.Assuch,theydescribethefullchainofclimatechange,fromproductionofgreenhousegasestoatmosphericresponses.Thisnecessarilyincludesrelevantlinksandfeedbacksbetweensocioeconomicandbiophysicalprocesses.Intendednationallydeterminedcontribution(INDC):INDCsaresubmissionsfromcountriesdescribingthenationalactionsthattheyintendtotaketoreachtheParisAgreement’slong-termtemperaturegoaloflimitingwarmingtowellbelow2°C.OnceacountryhasratifiedtheParisAgreement,itsINDCisautomaticallyconvertedtoitsNDC,unlessitchoosestofurtherupdateit.KatowiceClimatePackage:TheKatowiceClimatePackage,alsoknownas‘theKatowiceoutcome’,isacomplexpackagecontainingoperationalguidanceoninformationprovision,communicationandrulesforthefunctioningoftheclimatetransparencyframework,theglobalstocktakingofoverallprogressandtheevaluationofprogress,andtheprovisionofpriorinformationonfinancialassistance.ThepackagesetsouttheessentialproceduresandmechanismsthatoperationalizedtheParisAgreement.Theguidelinesofthepackageaimtobuildgreatertrustandstrengtheninternationalcooperation.KyotoProtocol:Aninternationalagreement,standingonitsown,andrequiringseparateratificationbygovernments,butlinkedtotheUnitedNationsFrameworkConventiononClimateChange.TheKyotoProtocol,amongotherthings,setsbindingtargetsforthereductionofgreenhousegasemissionsbyindustrializedcountries.Landuse,land-usechangeandforestry(LULUCF):Agreenhousegasinventorysectorthatcoversemissionsandremovalsofgreenhousegasesresultingfromdirecthuman-inducedlanduse,land-usechangeandforestryactivities.Leakage:Aphenomenonwherebythereductioninemissions(relativetoabaseline)inajurisdiction/sectorassociatedwiththeimplementationofmitigationpolicyisoffsettosomedegreebyanincreaseoutsidethejurisdiction/sectorthroughinducedchangesinconsumption,production,prices,landuseand/ortradeacrossthejurisdictions/sectors.Leakagecanoccuratanumberoflevels:project,state,province,nationorworldregion.XIIIEmissionsGapReport2021:TheHeatIsOnLeast-costpathway:Suchscenariosidentifytheleastexpensivecombinationofmitigationoptionstofulfilaspecificclimatetarget.Aleast-costscenarioisbasedonthepremisethat,ifanoverarchingclimateobjectiveisset,societywantstoachievethisatthelowestpossiblecostsovertime.Italsoassumesthatglobalactionsstartatthebaseyearofmodelsimulations(usuallyclosetothecurrentyear)andareimplementedfollowingacost-optimal(cost-efficient)sharingofthemitigationburdenbetweencurrentandfuturegenerationsdependingonthesocialdiscountrate.Likelychance:Alikelihoodgreaterthan66percentchance.Usedinthisassessmenttoconveytheprobabilitiesofmeetingtemperaturelimits.Mitigation:Inthecontextofclimatechange,mitigationrelatestoahumaninterventiontoreducethesources,orenhancethesinksofgreenhousegases.Examplesincludeusingfossilfuelsmoreefficientlyforindustrialprocessesorelectricitygeneration,switchingtosolarenergyorwindpower,improvingtheinsulationofbuildingsandexpandingforestsandother‘sinks’toremovegreateramountsofCO2fromtheatmosphere.Nationallydeterminedcontribution(NDC):SubmissionsbycountriesthathaveratifiedtheParisAgreementwhichpresentstheirnationaleffortstoreachtheParisAgreement’slong-termtemperaturegoaloflimitingwarmingtowellbelow2°C.NeworupdatedNDCswereexpectedtobesubmittedin2020andshouldbesubmittedeveryfiveyearsthereafter.NDCsthusrepresentacountry’scurrentambition/targetforreducingemissionsnationally.Offset(inclimatepolicy):AunitofCO2eemissionsthatisreduced,avoidedorsequesteredtocompensateforemissionsoccurringelsewhere.Recovery-typemeasure:Fiscal,monetaryorregulatoryinterventionbyagovernmenttoreinvigorateeconomicactivityinresponsetoacrisis.Rescue-typemeasure:Immediatefiscal,monetaryorregulatoryinterventionbyagovernmenttoprotectcitizens’livesandsocioeconomicwell-beingand/ortoprovideemergencysupporttobusinessesandtheeconomyinresponsetoacrisis.Scenario:Adescriptionofhowthefuturemayunfoldbasedon‘if-then’propositions.Scenariostypicallyincludeaninitialsocioeconomicsituationandadescriptionofthekeydrivingforcesandfuturechangesinemissions,temperatureorotherclimatechange-relatedvariables.SharedSocioeconomicPathways(SSP):Scenariosofprojectedsocioeconomicglobalchangesupto2100.Theyareusedtoderivegreenhousegasemissionsscenariosassociatedwithdifferentclimatepoliciesscenarios.Source:Anyprocess,activityormechanismthatreleasesagreenhousegas,anaerosoloraprecursorofagreenhousegasoraerosolintotheatmosphere.XVEmissionsGapReport2021:TheHeatIsOnForewordForewordClimatechangeisnolongerafutureproblem.Itisa'now'problem.Aswesawthisyear,devastatingimpactsarespreadingacrosstheglobeandgrowingeverstronger.TheIntergovernmentalPanelonClimateChangetoldusafewmonthsagothatwehavea50percentchanceofexceedinga1.5°Ctemperaturethresholdwithinthenextfewdecades.Climateactionsofarhasbeencharacterizedbyweakpromises,notyetdelivered.AstheEmissionsGapReport2021shows,theupdatednationallydeterminedcontributions(NDCs)undertheParisAgreementfallintothesametrap.Thesepledgesonlytake7.5percentoffpredicted2030emissions,comparedtothepreviousroundofcommitments.Thisisfarfromadequate.Reductionsof30percentareneededtostayontheleast-costpathwayfor2°Cand55percentfor1.5°C.IfnationsonlyimplementunconditionalNDCsastheystand,wearelikelytohitglobalwarmingofabout2.7°Cbytheendofthecentury.Currentnet-zeropledgescouldcutanother0.5°Coffglobalwarming–butthesepledgesarestillambiguous,delayedinmanycasesandnotfoldedintoNDCs.Atthesametime,thisyear’sEmissionsGapReportshowsthattheopportunitytousepandemicrecoveryspendingtoreduceemissionshasbeenlargelymissed.Togetontracktolimitglobalwarmingto1.5°C,theworldneedstotakeanadditional28gigatonsofcarbondioxideequivalent(GtCO2e)offannualemissionsby2030,overandabovewhatispromisedinupdatedunconditionalNDCs.Forthe2°CParisAgreementtarget,theadditionalneedislower:adropinannualemissionsof13GtCO2eby2030.Tobeclear:wehaveeightyearstomaketheplans,putinplacethepolicies,implementthemandultimatelydeliverthecuts.Theclockistickingloudly.Nationsmustputinplacethepoliciestomeettheirnewcommitmentsandstartimplementingthemimmediately.Thentheymustzeroinonnetzero,ensuringtheselong-termcommitmentsarelinkedtotheNDCs,andthatactionisbroughtforward.Itistimetogetthepoliciesinplacetobacktheraisedambitionsand,again,startimplementingthem.Thiscannothappeninfiveyears.Orinthreeyears.Thisneedstostarthappeningnow.Wecanstilldoit.Asthisyear’sEmissionsGapReportshows,thereishugepotentialforlargecutsinmethaneemissionsfromtheoilandgas,wasteandagriculturesectors.Carbonmarketscouldhelptoaccelerateactionbydecreasingmitigationcosts.COVID-19recoveryfundingcanstillbegreened.AndaspreviousUNEPEmissionsGapReportsshow,thereispotentialinnature-basedsolutions,renewables,energyefficiencyandsomuchmore.Weshouldnotdespair.Wehavealreadyshownthatclimateactioncanmakeadifference.In11years,from2010to2021,wehaveputinplacepoliciesthatwilllowerannualemissionsby11GtCO2ein2030comparedtowhatwouldhavehappenedwithoutthesepolicies.Butweneedtomakethedifference,notadifference.Wecannotkeepdoingthesamethingsandexpectabetterresult.Theworldhastowakeuptotheimminentperilwefaceasaspecies.Weneedtogofirm.Weneedtogofast.Andweneedtostartdoingitnow.IngerAndersenExecutiveDirectorUnitedNationsEnvironmentProgrammeXVIEmissionsGapReport2021:TheHeatIsOnExecutivesummaryIntroductionThistwelftheditionoftheUnitedNationsEnvironmentProgramme(UNEP)EmissionsGapReportcomesduringayearofconstantremindersthatclimatechangeisnotinthedistantfuture.Extremeweathereventsaroundtheworld–includingflooding,droughts,wildfires,hurricanesandheatwaves–havecontinuouslyhitthenewsheadlines.Thousandsofpeoplehavebeenkilledordisplacedandeconomiclossesaremeasuredinthetrillions.Bearingwitnesstotheincreasinglyclearsignsofclimatechange,theIntergovernmentalPanelonClimateChange(IPCC)publishedthefirstreportinitsSixthAssessmentcycleaddressingthe“PhysicalScienceBasis”inAugust2021.Dubbeda“coderedforhumanity”bytheUnitedNationsSecretary-General,theIPCCreportdocumentsinfargreaterdetailandwithhighercertaintythanpreviousassessmentshowclimatechangeandextremeeventscanbeattributedtothebuild-upofanthropogenicgreenhousegas(GHG)emissionsintheatmosphere.Thereisafifty-fiftychancethatglobalwarmingwillexceed1.5°Cinthenexttwodecades,andunlessthereareimmediate,rapidandlarge-scalereductionsinGHGemissions,limitingwarmingto1.5°Coreven2°Cbytheendofthecenturywillbebeyondreach.BuildingonthenewevidencefromtheIPCC,thetwenty-sixthUnitedNationsClimateChangeConferenceoftheParties(COP26)ischargedwiththegrowingurgencyofacceleratingglobalambitionandactiononbothmitigationandadaptation.Thisyear,thespotlightisonthenewandupdatednationallydeterminedcontributions(NDCs)thatcountrieswererequestedtosubmitinadvanceofCOP26.AstheSeptember2021versionoftheNDCSynthesisReportpublishedbytheUnitedNationsFrameworkConventiononClimateChange(UNFCCC)illustrates,thenewandupdatedNDCsareinsufficienttoachievethetemperaturegoaloftheParisAgreement.ThisEmissionsGapReportconfirmsthefindingsoftheUNFCCCreport.Itexpandstheassessmenttoconsiderannouncedmitigationpledgesfor2030inadditiontothenewandupdatedNDCs.ThereportshowsthatneworupdatedNDCsandannouncedpledgesfor2030haveonlylimitedimpactonglobalemissionsandtheemissionsgapin2030,reducingprojected2030emissionsbyonly7.5percent,comparedwithpreviousunconditionalNDCs,whereas30percentisneededtolimitwarmingto2°Cand55percentisneededfor1.5°C.Ifcontinuedthroughoutthiscentury,theywouldresultinwarmingof2.7°C.Theachievementofthenet-zeropledgesthatanincreasingnumberofcountriesarecommittingtowouldimprovethesituation,limitingwarmingtoabout2.2°Cbytheendofthecentury.However,the2030commitmentsdonotyetsetG20members(accountingforcloseto80percentofGHGemissions)onaclearpathtowardsnetzero.Moreover,G20membersasagroupdonothavepoliciesinplacetoachieveeventheNDCs,muchlessnetzero.Turningtosomeoftheopportunitiesforbridgingtheemissionsgapandgettingontracktonetzero,thereportassessestheextenttowhichCOVID-19fiscalrecoverymeasuresareusedtoaccelerateagreentransition.Itexaminesthescopeforreducingemissionsfrommethane,thesecond-most-importantGHGintermsofcurrentanthropogenicclimateforcing,tobridgethegapandgetontracktonetzero.Finally,thereportlooksintoakeynegotiationissueforCOP26:reachingagreementonhowtomoveforwardwitharticle6oftheParisAgreementdealingwithcooperativeapproachesandmarketmechanisms.AlargenumberofcountrieshaveincludedtheuseofmarketmechanismsintheirNDCimplementationplansandarewaitingforthemodalitiestobeagreed.Atthesametime,theuseofmarketsandoffsetsinmeetingnet-zeroemissiongoalsisoftenunclear.Asinpreviousyears,the2021EmissionsGapReporthasbeenguidedbyanexperiencedsteeringcommitteeandpreparedbyaninternationalteamofleadingscientists,assessingallavailableinformation,includingthatpublishedinthecontextoftheIPCCreports,aswellasinotherrecentscientificliterature.Theassessmentprocesshasbeentransparentandparticipatory.Theassessmentmethodologyandpreliminaryfindingsweremadeavailabletothegovernmentsofthecountriesspecificallymentionedinthereporttogivethemanopportunitytocommentonthefindings.XVIIEmissionsGapReport2021:TheHeatIsOn1.Followinganunprecedenteddropof5.4percentin2020,globalcarbondioxideemissionsarebouncingbacktopre-COVIDlevels,andconcentrationsofGHGsintheatmospherecontinuetorise.▶TheCOVID-19pandemicledtoanunprecedented5.4percentdropinglobalfossilcarbondioxide(CO2)emissionsin2020(figureES.1).DataarenotyetavailableforallGHGemissionsin2020,butthedropintotalglobalGHGemissionsisanticipatedtobesmallerthanthedropinfossilCO2emissions.▶Astrongreboundinemissionsisexpectedin2021.PreliminaryestimatessuggestfossilenergyFigureES.1.Globalgreenhousegasemissionsfromallsources,1970–2020CO2emissionscouldgrowby4.8percentin2021(excludingcement),andglobalemissionsin2021areexpectedtobeonlyslightlylowerthantherecordlevelof2019.▶DespitethelargedeclineinCO2emissionsin2020,theconcentrationofCO2intheatmospheregrewbyaround2.3partspermillion,inlinewithrecenttrends.Itisunlikelythatthereductionsinemissionsin2020willbedetectibleintheatmosphericgrowthrate,asthenaturalvariabilityofaroundonepartpermillionisfargreaterthantheeffectofa5.4percentreductioninCO2emissionsinasingleyear.Solvingtheclimateproblemrequiresrapidandsustainedreductionsinemissions.2.Newmitigationpledgesfor2030showsomeprogress,buttheiraggregateeffectonglobalemissionsisinsufficient.▶Asat30September2021,120countries(121parties,includingtheEuropeanUnionandits27memberstates)representingjustoverhalfofglobalGHGemissions,havecommunicatedneworupdatedNDCs.Thisyear'sassessmentconsiderstheneworupdatedNDCscommunicatedtotheUNFCCCaswellasannouncementsofnewmitigationpledgesfor2030byChina,JapanandtheRepublicofKoreanotsubmittedasNDCsby30September.▶Justunderhalf(49percent)oftheneworupdatedNDCssubmitted(fromcountriesaccountingfor32percentofglobalemissions)resultinlower2030emissionsthanthepreviousNDC.Around18percentoftheNDCs(fromcountriesaccountingfor13percentofglobalemissions)willnotreduce2030emissionsrelativetothepreviousNDC.Theremaining33percentofNDCs(fromcountriesaccountingfor7percentofglobalemissions)containinsufficientdetailtoassesstheirimpactonemissionsrelativetothepreviousNDC(figureES.2).Typically,thisisduetoalackofinformationinthepreviousNDC,ratherthanthecurrentone;thecurrentNDCsaremoretransparent.202020152010200520001995199019851980197519700605040302010CH4LULUCFCO2FossilCO2N2OF-gases2020dataonlyavailableforfossilandLULUCFCO2Globalgreenhousegasemissions(GtCO2e)XVIIIEmissionsGapReport2021:TheHeatIsOnFigureES.2.Effectofneworupdatednationallydeterminedcontributionson2030greenhousegasemissionsrelativetopreviousnationallydeterminedcontributions▶OfthecountriesthathavesubmittedneworupdatedNDCs,more(89percent)haveGHGtargetsthanbefore(75percent).However,thesetargetsareonlymarginallymorecomprehensiveintermsofsectorandgascoverage.TheshareofneworupdatedNDCsthatarecompletelyunconditionalhasincreasedfrom24percentto26percent,whiletheshareofNDCsthatarecompletelyconditionalhasdroppedfrom31percentto18percent.▶TheaggregateimpactoftheneworupdatedNDCsformallysubmittedislimited:neworupdatedunconditionalNDCsareestimatedtoleadtoatotalreductionin2030globalGHGemissionsofabout2.9gigatonsofCO2equivalent(GtCO2e),comparedwiththepreviousNDCs(figureES.3).Thisestimateincludesreductionsofaround0.3GtCO2eresultingfromotherfactors,includinglowerprojectionsofinternationalaviationandshippingemissions,andadjustmentsofcountriesthatareprojectedtooverachievetheirNDCtargets.IftheannouncedpledgesofChina,JapanandtheRepublicofKoreaarealsoincluded,thisaggregatereductionincreasestojustover4GtCO2e.Theimpactofconditionaltargetsisofsimilarmagnitude.▶TakingacloserlookattheG20members,thecombinedimpactofsubmittedNDCsandannouncedGHGreductiontargetsfor2030isanannualreductionofabout3GtCO2ecomparedwiththepreviousNDCs.SixG20membershaveformallysubmittedupdatedNDCswithenhancedGHGmitigationpledges:Argentina,Canada,theEU27(countingtheEU27anditsthreeindividualG20memberstatesFrance,GermanyandItalyasone),SouthAfrica,theUnitedKingdomandtheUnitedStatesofAmerica–allofwhichentailreducedemissionsin2030ofabout2.1GtCO2ecomparedwithpreviousNDCs.TwoG20members(BrazilandMexico)havesubmittedtargetsthatleadtoanincreaseinemissionsof0.3GtCO2e,bringingthenetreductioninglobalGHGemissionsofneworupdatedNDCssubmittedbyG20membersto1.8GtCO2eannuallyby2030.Inaddition,China,JapanandtheRepublicofKoreahaveannouncedenhancedpledgesthatresultinannualreductionsofabout1.2GtCO2e,buthavenotyetformallycommunicatedthemtotheUNFCCC.▶ThelargestreductionscomefromtheUnitedStatesofAmerica,theEU27,theUnitedKingdom,ArgentinaandCanada(submitted)andChinaandJapan(announced).TwoG20members(AustraliaandIndonesia)havesubmittedNDCtargets,whichareassessednottoleadtoadditionalreductionrelativetothepreviousNDCs.OneG20member(theRussianFederation)hassubmittedanNDCthatimprovesuponitspreviousNDC,butstilldoesnotgobeyonditscurrentpoliciesandanotherthreeG20members(India,SaudiArabiaandTurkey)havenotyetsubmittedaneworupdatedNDC.NeworupdatedNDCwithlower2030emissionsthanpriorNDCNeworupdatedNDCnotcomparabletopriorNDCNeworupdatedNDCwithequalorhigher2030emissionsthanpriorNDCNoneworupdatedNDCsubmittedXIXEmissionsGapReport2021:TheHeatIsOn▶Incomparison,theaggregateimpactoftheneworupdatedNDCsubmissionsforthenon-G20membersisanannualreductionof0.8GtCO2eby2030.3.Asagroup,G20membersarenotontracktoachieveeithertheiroriginalornew2030pledges.TenG20membersareontracktoachievetheirpreviousNDCs,whilesevenareofftrack.▶Whenconsideringtheimpactofnewpledges,itshouldbenotedthatcollectivelytheG20membersarenotyetontracktoachievetheirpreviousNDCs.IfcurrentpolicyprojectionsareusedforthosecountrieswherepolicyprojectionsarelowerthanwhatNDCswoulddeliver,theG20membersasaFigureES.3.Impactof2030pledges(nationallydeterminedcontributionsandotherannouncedpledges)on2030globalemissionscomparedwithpreviousnationallydeterminedcontributionsubmissionsgroupareprojectedtofallshortofachievingtheirunconditionalNDCsby1.1GtCO2eannually.▶Only10G20members(Argentina,China,EU27,India,Japan,theRussianFederation,SaudiArabia,SouthAfrica,TurkeyandtheUnitedKingdom)arelikelytoachievetheiroriginalunconditionalNDCtargetsundercurrentpolicies.Amongthem,threemembers(India,theRussianFederationandTurkey)areprojectedtoreducetheiremissionstolevelsatleast15percentlowerthantheirpreviousunconditionalNDCemissionstargetlevelsundercurrentpolicies,indicatingthatthesecountrieshavesignificantroomforraisingtheirNDCambition.Asat30September2021,IndiaandTurkeyhavenotyetsubmittedaneworupdatedNDC,whiletheRussianFederationhassubmittedanewNDCthatreducesemissions,butstillresultsinhigheremissionsthanimpliedbycurrentpolicies.Non-G20OtherfactorsOtherfactorsTotalTotalMexicoSaudiArabiaIndonesiaChinaArgentinaSouthAfricaAustraliaTurkeyUSABrazilCanadaJapanEU27IndiaUKIncreasedemissionsReducedemissionsMtCO2e0-4,000-3,000-2,000-1,000500-500-4,500-3,500-2,500-1,500ImpactofannouncedpledgesTotalimpactRussianFederationRepublicofKoreaXXEmissionsGapReport2021:TheHeatIsOnAustralia,Brazil,Canada,Mexico,theRepublicofKoreaandtheUnitedStatesofAmericaareallassessedtorequirestrongerpoliciestoachievepriorNDCs,whilethereisinsufficientinformationtoassesstheprogressofIndonesia.▶G20membershaveadoptedarangeofpoliciesinrecentyears.Whiletherearemanypositivedevelopments,therearealsonegativeexamples,suchasfossilfuelextractionprojectsandcoal-firedpowerplantconstructionplansmovingforwardaswellasrollbackofenvironmentalregulationsduringtheCOVID-19pandemic.Basedonthecentralestimatesofindependentstudies,alargenumberofG20members(Argentina,Brazil,China,India,Indonesia,Mexico,theRussianFederationandSaudiArabia)areexpectedtoemitmorein2030underimplementedpoliciesthantheydidin2010.▶Collectively,theG20membersareprojectedtofallshortoftheirneworupdatedunconditionalNDCsandotherannouncedmitigationpledgesfor2030.Thisistobeexpectedanditwouldindicatealackofenhancedambitionifthenew2030pledgeswereprojectedtobeachievedwithcurrentlyimplementedpolicies.ItisworthnotingthatCanadaandtheUnitedStatesofAmericahavesubmittedstrengthenedNDCtargets,whileindependentstudiessuggestthattheyarenotontracktomeettheirpreviousNDCtargetswithcurrentlyimplementedpolicies.ThesetwocountriesthereforeneedtomakesignificantadditionaleffortstomeettheirnewNDCtargets.4.Apromisingdevelopmentistheannouncementoflong-termnet-zeroemissionspledgesby50parties,coveringmorethanhalfofglobalemissions.However,thesepledgesshowlargeambiguities.▶Net-zeroemissionsisastatewherethesumofallanthropogenicemissionsandremovalsiszero.Net-zeroemissionstargetsarebeingdefinedinavarietyofways–themostimportantaspectfromaglobalgeophysicalperspectivebeingwhethertheycoverallGHGsorCO2only.Globalnet-zeroCO2emissionsstabilizeglobalwarming,whereasnet-zeroGHGemissionsresultinapeakthenadeclineinglobalwarming.Toalignwitha1.5°Climit,globalCO2emissionsmustreachnetzeroaround2050,withglobalGHGemissionsreachingnetzero15–20yearslater.Adelayof15–20yearsineithernet-zeroCO2ornet-zeroGHGsimplieslimitingwarmingto2°Cratherthan1.5°C.▶Globally,49countriesandoneparty(theEU27inadditiontothenet-zeropledgesmadebyitsindividualmemberstates)havepledgedanet-zeroemissionstargetthatisstatedinnationallegislation,inapolicydocumentorinapublicannouncementbythegovernmentorahigh-levelgovernmentofficial.ThesepledgescovermorethanhalfofcurrentglobaldomesticGHGemissions,overhalfofgrossdomesticproduct(GDP)andonethirdoftheglobalpopulation.Eleventargetscovering12percentofglobalemissionsareenshrinedinlaw.▶Bynumber,themajorityofthesetargets(38)arefor2050,coincidentwiththemid-centurytimescaleforglobalCO2emissionsindicatedbytheIPCCasnecessaryforlimitingwarmingto1.5°C.Eighttargetsareaimedatearlieryears(2030–2045)andfouratlateryears.Intermsofemissions,however,thetargetsaresplitalmostentirelyandequallybetween2050(duetotheEuropeanUnionandUnitedStatesofAmericapledges)and2060(duetoChina’spledge).▶ExistingtargetsshowvariationsinscopeandlargeambiguitieswithrespecttotheinclusionofsectorsandGHGs.Themajorityarefurthermoreunclearorundecidedontheinclusionofemissionsfrominternationalaviationandshippingandtheuseofinternationaloffsets.5.FewoftheG20members'NDCtargetsputemissionsonaclearpathtowardsnet-zeropledges.Thereisanurgentneedtobackthesepledgesupwithnear-termtargetsandactionsthatgiveconfidencethatnet-zeroemissionscanultimatelybeachievedandtheremainingcarbonbudgetkept.▶TwelveG20memberscoveringjustoverhalfofglobaldomesticGHGemissionshavecurrentlypledgedanet-zerotarget,ofwhichsixareinlaw,twoareinpolicydocumentsandfouraregovernmentannouncements.Allarefortheyear2050,withtheexceptionofChina’s2060targetandGermany’stargetfor2045.TheremainingeightG20membershavesofarnotsetnet-zerotargets,butthreeofthemhavecommunicatedlong-termlowGHGemissiondevelopmentstrategiestotheUNFCCC(Indonesia,MexicoandSouthAfrica).▶G20pledgesalsoshowambiguity.Mosttargetsareunclearorundecidedontheinclusionofoffsetsandofinternationalaviationandshippingemissions.LackofclarityisalsonotableoncoverageofXXIEmissionsGapReport2021:TheHeatIsOnsectorsandgases,butpledgesthatareclearshowatendencyforcomprehensivecoverage.However,mostshowalackoftransparencyregardingtheapproachtakentofairness,theplansforachievement(includingonuseofremovals),andprogressreportingandreview.OnlyCanada,theEuropeanUnion,France,GermanyandtheRepublicofKoreahavepublishedtheirplansatthetimeofcompletingthisreport,andonlythesecountriesplustheUnitedKingdomhaveaccountableprocessesforreviewingtheirtargets.▶Thepathwaytonetzerocounts:thepathfollowedfromtodayuntilnet-zeroCO2emissionsarereacheddeterminesthetotalamountofemittedCO2andtherebythetotalcarbonbudgetused(seebulletbelow).Whetheralinear,anaccelerated,oradelayedpathisfollowedwillaffecttheclimateoutcome(figureES.4).▶GlobalwarmingisclosetolinearlyproportionaltothetotalnetamountofCO2thathaseverbeenemittedintheatmosphereasaresultofhumanactivities.Therefore,limitingglobalwarmingtoaspecifiedlevelrequiresthatthetotalamountofCO2emissionseveremittedbekeptwithinafinitecarbonbudget.NewIPCCestimatesputtheremainingcarbonbudgettolimitwarmingto1.5°Crelativetopre-industriallevels,with66percentchance,at400GtCO2.For2°C,theestimateis1,150GtCO2.CurrentannualglobalCO2emissionsareabove40GtCO2/year,meaningthaturgentanddeepemissionsreductionsoverthenextdecadearerequiredtostaywithintheremainingbudgets.▶Asanindicationoftheconsistencybetweennearer-termactionsandnet-zerotargets,figureES.5plotstheemissionspathsforasubgroupofG20membersimpliedbytheircurrentNDCsandFigureES.4.Near-termtargetsarecriticaltosetglobalemissionsonaclearpathtowardsachievinglong-termnet-zerotargetsandstringentclimategoals02040Globaltotalgreenhousegasemissions[GtCO2e/yr]60onadelayedpath=near-termtargetssettingemissions...Additionalcumulativeemissionsleadingtohigherwarming,highermitigationchallenges,andgreaterdifficultyinachievingthenet-zerotargetonalinearpath,oronanacceleratedpath...towardsachievingthelong-termnet-zerotarget2020204020602080210020102030205020702090Accelerated:theNDCreducesemissionsfurtherthanimpliedbyalinearpathtowardsthenet-zerotarget.Cumulativeemissionsarefurtherreducedcomparedtoalinearpath.Linear:theNDCsetsemissionsapproximatelyonalinearpathtowardsachievingthenet-zerotarget.Delayed:theNDCreducesemissionsmoreslowlythanimpliedbyalinearpathtowardsthenet-zerotarget.Cumulativeemissionsandresultingglobalwarmingarehighercomparedtoalinearpath.XXIIEmissionsGapReport2021:TheHeatIsOnFigureES.5.Overviewofnet-zeropathwaysimpliedbyclimatepledgesbyselectedG20members20202004000MtCO2e/yr20402060ArgentinaMtCO2e/yr5000202020402060CanadaMtCO2e/yr1,0000202020402060Brazil202020402060ChinaMtCO2e/yr05,00010,000MtCO2e/yr1,0005000202020402060JapanMtCO2e/yr2,0000202020402060EU27MtCO2e/yr202020402060RepublicofKorea0500MtCO2e/yr202020402060UnitedStates5,0000MtCO2e/yr0500202020402060UnitedKingdomNote:OnlyG20memberswithnetzerotargetsareincluded.MemberstatesoftheEuropeanUnionhavenoseparateassessmentoftheirpathtonetzero,becausetheirNDCisnotassessedseparatelyaspartofthisreport.XXIIIEmissionsGapReport2021:TheHeatIsOntheirnet-zerotarget.OfthenineG20membersforwhichanemissionspathcanbeestimatedbasedontheirnet-zerotargetandtheirNDC,nonehaveNDCtargetsthatputthemonanacceleratedpathtowardstheirnet-zeroemissionstargets.Fiveoftheseninemembers,accountingforaboutonefifthofglobaldomesticGHGemissions,haveNDCtargetsthatputthecountry’sdomesticemissionsontoalinearpathtowardsachievingtheirnet-zerotargets.Intheotherfourcases,theNDCsleadtoemissionsin2030thatareabout25percentto95percenthigherthanalinearpathtowardstheirnet-zerotargetswouldimply.Recognizingthatcountriesfaceverydifferentcircumstances,thesecountriesurgentlyneedstrengthenedandmoreambitiousnear-termclimateplansfortheirnet-zerotargetstoremainachievable.▶Thereisanurgentneedfor(i)moreG20members–andindeedallcountries–topledgenet-zeroemissions,(ii)allcountriestoincreasetherobustnessoftheirnet-zeropledges,and(iii)allnet-zerotargetstobebackedupbynear-termactionsthatgiveconfidencethatthenet-zerotargetscanultimatelybeachieved.6.Theemissionsgapremainslarge:comparedtopreviousunconditionalNDCs,thenewpledgesfor2030reduceprojected2030emissionsbyonly7.5percent,whereas30percentisneededfor2°Cand55percentisneededfor1.5°C.▶Asinpreviousreports,theemissionsgapfor2030isdefinedasthedifferencebetweentotalglobalGHGemissionsfromleast-costscenariosthatkeepglobalwarmingto2°C,1.8°Cor1.5°CwithvaryinglevelsoflikelihoodandtheestimatedtotalglobalGHGemissionsresultingfromthefullimplementationoftheNDCs.▶Thisyear,theNDCscenariohasbeenexpandedtoincludeallthemostrecentNDCs(neworupdatedNDCsifsubmitted,andpreviousNDCsotherwise)aswellasallofficiallyannouncedclimatechangemitigationpledgesfor2030withacut-offdateof30August2021.Thethreeleast-costscenariosconsistentwiththeParisAgreementhavebeenupdatedandtheirtemperatureoutcomesre-assessedbasedontheContributionofWorkingGroupItotheSixthAssessmentReportoftheIntergovernmentalPanelonClimateChange.Asaresult,globalemissionsin2030consistentwithkeepingglobalwarmingbelow2.0°Cwitha66percentchancearenowestimatedat39GtCO2e,whichisabout2GtCO2elowerthaninearlierreports.Similarly,theestimatefor1.8°Cisabout2GtCO2elowerthanthe1.8°Cestimateofpreviousreports.Therearenochangestothe1.5°Cestimate(tableES.1).Thisimpliesthatwhiletheaggregateeffectonglobalemissionsin2030ofneworupdatedNDCsandannouncedpledgesisestimatedat4GtCO2e(seepointtwoofthissummary),thegapwithrespectto2°Cisonlyreducedby2GtCO2ecomparedwithlastyear.▶TheupdatedcurrentpoliciesscenarioisestimatedtoreduceglobalGHGemissionsin2030toabout55GtCO2e(range:52–58GtCO2e)in2030,whichis4GtCO2elowerthanthemedianestimateofthe2020EmissionsGapReportand9GtCO2elowerthanthe2010-policiesscenario(tableES.1).Aroundhalfofthedecreasebetweenthe2020and2021Reportsreflectsclimatepolicyprogressinthecountries,whiletheotherhalfisbecauseofthegeneralslowdownofeconomiesduetotheCOVID-19pandemic.▶Collectively,countriesarefallingshortofmeetingtheirneworupdatedNDCsandannouncedpledgeswithcurrentpolicies.Thisimplementationgapin2030is3GtCO2eforunconditionalNDCsand5GtCO2eforconditionalNDCs.▶Comparedtolastyear,theemissionsgapisonlyslightlynarrowedbytheneworupdatedNDCsandannouncedmitigationpledges.By2030,annualemissionsneedtobe13GtCO2e(range:10–16GtCO2e)lowerthancurrentunconditionalNDCsimplyforthe2°Cgoal,and28GtCO2e(range:25–30GtCO2e)lowerforthe1.5°Cgoal.Bothestimatesarefora66percentchanceofstayingbelowthestatedtemperaturelimit.IfconditionalNDCsarealsoconsidered,thesegapsarereducedbyaround2GtCO2eand3GtCO2erespectively(figureES.6,tableES.1).XXIVEmissionsGapReport2021:TheHeatIsOn7.Globalwarmingattheendofthecenturyisestimatedat2.7°Cifallunconditional2030pledgesarefullyimplementedand2.6°Cifallconditionalpledgesarealsoimplemented.Ifthenet-zeroemissionspledgesareadditionallyfullyimplemented,thisestimateisloweredtoaround2.2°C.▶Toestimatetheglobalwarmingimplicationsattheendofthiscentury,estimatedemissionsfortheyear2030areprojectedoutto2100,andtheirclimateoutcomesassessedusingaclimatemodel.Thisapproachassumesacontinuationofclimateactionbeyond2030,withoutfurtherstrengthening.ExtrapolationsuntiltheendoftheTableES.1.Totalglobalgreenhousegasemissionsin2030underdifferentscenarios,temperatureimplications,andtheresultingemissionsgapScenario(roundedtothenearestgigaton)NumberofscenariosinsetGlobaltotalemissionsin2030[GtCO2e]EstimatedtemperatureoutcomesClosestcorrespondingIPCCSR1.5scenarioclassEmissionsgapin2030[GtCO2e]50%chance66%chance90%chanceBelow2.0°CBelow1.8°CBelow1.5°CYear2010policies664(60–68)Currentpolicies955(52–58)15(12–18)22(19–25)30(28–33)UnconditionalNDCs(updatedNDCsandannouncements)852(49–55)13(10–16)19(16–22)28(25–30)ConditionalNDCs(updatedNDCsandannouncements)850(46–52)11(7–13)17(13–19)25(22–28)Below2.0°C(66%chance)7139(33–49)Peak:1.7–1.8°CIn2100:1.3–1.7°CPeak:1.8–2.0°CIn2100:1.5–1.9°CPeak:2.2–2.4°CIn2100:1.9–2.4°CHigher-2°CpathwaysBelow1.8°C(66%chance)2333(27–41)Peak:1.6–1.7°CIn2100:1.2–1.6°CPeak:1.7–1.8°CIn2100:1.4–1.8°CPeak:2.0–2.2°CIn2100:1.8–2.2°CLower-2°CpathwaysBelow1.5°C(66%chancein2100withnoorlimitedovershoot)2625(17–33)Peak:1.5–1.6°CIn2100:1.0–1.3°CPeak:1.6–1.7°CIn2100:1.2–1.5°CPeak:1.9–2.1°CIn2100:1.5–1.9°C1.5°Cwithnoorlimitedovershootcenturyareinherentlyuncertainandsubjecttoscenarioassumptions,suchasthelevelatwhichclimateactioncontinuesortechnologycosts.Thisuncertaintyiscurrentlyoftheorderof±0.5°Caroundthebest-estimate2.7°Cprojection,butisreducedto±0.3°Cwhentakingintoaccountcountries’net-zerotargets.Furthermore,itshouldbenotedthatthisyear’sestimatesarebasedonimprovedmethodsandthelatestclimateassessmentofWorkingGroupIintheIPCCSixthAssessmentReport(AR6).ThesemethodologicalupdatesalonelowertemperatureprojectionsforunconditionalNDCsbyabout0.2°Ccomparedtolastyear'sestimates.XXVEmissionsGapReport2021:TheHeatIsOnFigureES.6.Globalgreenhousegasemissionsunderdifferentscenariosandtheemissionsgapin2030(medianestimateandtenthtoninetiethpercentilerange)20.030.040.050.060.070.0201520202025GtCO2e0.010.020.030.040.050.060.070.020152020202520302035204020452050Currentpoliciesscenario2010policiesscenarioRemaininggaptostaywithin2°ClimitRemaininggaptostaywithin2°ClimitConditionalNDCandpledgescenarioUnconditionalNDCandpledgescenario13GtCO2e28GtCO2e25GtCO2eMedianestimateoflevelconsistentwith2°C:39GtCO2e(range33–49)Medianestimateoflevelconsistentwith1.5°C:25GtCO2e(range17–33)GtCO2e112°Crange1.8°Crange1.5°CrangeEstimatedglobalwarmingover21stcenturyCurrentpoliciesscenario:2.8°C(66%chance)UnconditionalNDCandpledgescenariowithnet-zerotargets:2.2°C(66%chance)UnconditionalNDCandpledgescenario:2.7°C(66%chance)GtCO2eTurquoiseareashowspathwayslimitingglobaltemperatureincreasetobelow2°Cwithabout66%chance.Greenareashowspathwayslimitingglobaltemperatureincreasetobelow1.5°Cwitha66%chanceby2100andminimum33%chanceoverthecourseofthecentury.2°Crange1.8°Crange1.5°CrangeXXVIEmissionsGapReport2021:TheHeatIsOnFigureES.7.GlobalrecoveryspendingasatMay2021acrosssectorsbyregion(US$billion).Low-carboninitiatives(top)andhigh-carboninitiatives(bottom)Note:R&Dstandsforresearchanddevelopment.▶Acknowledgingthesecaveats,acontinuationoftheneworupdatedunconditionalNDCsandpledgeannouncementsisestimatedtolimitwarmingto2.7°C(range:2.2–3.2°C)bytheendofthecenturywitha66percentchance.Ifconditionalpledgesarealsofullyimplemented,theseestimatesareloweredto2.6°C(range:2.1–3.1°C).Bycontrast,acontinuationofcurrentpolicies,whichareinsufficienttomeetthe2030pledges,isestimatedtolimitwarmingto2.8°C(range2.3–3.3°C).▶Thefullimplementationofthenet-zeropledges,inadditiontoneworupdatedunconditionalNDCsandannouncedpledges,furtherlowerthesetemperatureestimatesmarkedlyto2.2°C(range2.0–2.5°C)with66percentchance.Evenunderthisscenario,thereisstillmorethan15percentchancethatglobalwarmingwillexceed2.5°Cbytheendofthecentury,andjustshortof5percentchancethatitwillexceed3°C.Finally,theseestimatedimprovementsfromnet-zerotargetsshouldbecaveatedbythefactthatonlyafewcurrentNDCssetcountries’emissionsonalinearpathtowardsreachinglonger-termnet-zerotargets.8.TheopportunitytouseCOVID-19fiscalrescueandrecoveryspendingtostimulatetheeconomywhilefosteringalow-carbontransformationhasbeenmissedinmostcountriessofar.Poorandvulnerablecountriesarebeingleftbehind.▶TheCOVID-19pandemichasprecipitatedanenormousincreaseinpublicexpenditure,intheformof:(i)short-termrescuespending,tokeepbusinessesandpeoplealive;(ii)longer-termrecoveryinvestment,toreinvigoratetheeconomy;and(iii)reinforcementspending,toembedneweconomictrajectoriesintolong-termdevelopmentplans.Low-carbonrescuespendinghasincentivizeddecarbonizationthroughgreenconditionalitiesattachedtoshort-termbusinesssupport.Low-carbonrecoveryinvestmenthassetouttoacceleratethelow-carbontransitiondirectlybysupportinggreenprojectsandindirectlybyincorporatinggreenincentivesintotraditionalinvestment.Greenreinforcementinitiativesdeliverlong-termsupporttotheprojectsandsectorstargetedbygreenrecoveryinvestment.▶ApproximatelyUS$16.7trillionwasspenttoMay2021onCOVID-19-relatedrescueandrecoverypackages(excludingunallocatedEuropeanUnionfunds).However,mostresourceshavebeenforimmediaterescuespending,mostlyonunemploymentandworkersupportprogrammes,pandemicmanagement,andhealth-care050100150200US$250bnCleanenergy(4.1%)Naturalinfrastructure(3.8%)Cleantransport(3.3%)Traditionalenergy(1.6%)Armedforces(0.8%)Traditionaltransport(9.2%)CleanR&D(1.6%)Energyefficiency(2.2%)EuropeAfricaAsiaLatinAmerica&theCaribbeanNorthernAmericaOceaniaLow-carbonmeasuresHigh-carbonmeasuresFigure5.4XXVIIEmissionsGapReport2021:TheHeatIsOnservices.US$2.25trillionisconsideredrecoveryspending.Ofthis,onlyaround17–19percent(US$390–440billion)islikelytoreduceGHGemissions.▶Low-carbonfiscalspendinghascoveredawiderangeofsectors.Over500greenrescueandrecoverymeasureshavebeenintroducedglobally.Policieshavecoveredmostemergingandestablishedgreenindustries(figureES.7).Therangeofspendinghasbeennotablywiderinadvancedeconomies,withemergingmarketanddevelopingeconomiesfocusingtheirgreenrecoveryfundsoncleanenergygenerationandnaturalcapitalinvestments.▶Internationaldisparitiesarelargeintermsofbothtotalspendingandlow-carbonspending.Almost90percentofrecoveryspendingisaccountedforbysevencountries:theRepublicofKorea,Spain,Germany,theUnitedKingdom,China,FranceandJapan.TheGlobalRecoveryObservatoryfindsthat,uptoMay2021,France,Germany,Canada,Finland,NorwayandDenmarkcanbeclassifiedas‘leaders’ongreenrecovery,withgreenspendingasashareofrecoveryspendingrangingfrom39percentto75percent.TheUnitedKingdom,SpainandSwedenalsorankhighly,accordingtoVividEconomics’GreennessofStimulusIndex.▶Vulnerablenationsarebeingleftbehind.COVID-19spendinghasbeenfarlowerinlow-incomeeconomies(~US$60perperson)thanadvancedeconomies(~US$11,800perperson)(figureES.8).Lessdiversifiedeconomies,risingdebtasapercentageofGDP,andcorrespondinglimitedfiscalspacehaveconstrainedtheabilityofemergingeconomiesandlow-incomecountriestomobilizeresources.▶Withoutasubstantialincreaseinforeignaid,thedifferenceinspendingbetweenadvancedeconomiesandemergingmarketsanddevelopingeconomieswillexacerbategapsindevelopmentandrestrictprogressagainstclimatechange.Additionally,withoutsignificantlyincreasedclimatefinance,emergingmarketsanddevelopingeconomiesarelikelytobecometheworld’stopGHGemitters,allwhiledisproportionatelysufferingtheburdenofclimatechange,whichhashistoricallybeencausedprimarilybyhigh-incomenations.9.Reductionofmethaneemissionsfromthefossilfuel,wasteandagriculturesectorscancontributesignificantlytoclosingtheemissionsgapandreducewarmingintheshortterm.▶Methaneisthesecond-most-importantGHGintermsofcurrentanthropogenicclimateforcing,andglobalanthropogenicmethaneemissionscontinuetoincrease.▶Withalifetimeofabout12years,andaglobalwarmingpotential(GWP)ofapproximately82overa20-yearperiodand29overa100-yearperiod,reducingmethaneemissionsrepresentsFigureES.8.COVID-19-relatedspendingpercapitaacrossdevelopmentcategories(US$)AdvancedeconomiesUS$11,826perpersonEmergingmarketanddevelopingeconomiesUS$578perpersonLow-incomeeconomiesUS$57perpersonXXVIIIEmissionsGapReport2021:TheHeatIsOnanimportantopportunitytoslowdowntherateofwarmingintheshortterm,reducepeakwarmingduringthiscenturyandhelpbridgetheemissionsgapbetweencurrenttrajectoriesandthoseconsistentwiththe2°Cor1.5°Ctemperaturegoals.▶Strongabatementpotentialexistsatnet-negativeandlowcosts(<US$600/tCH4;<~US$20/tCO2eusingGWP100),especiallyinthefossilfuelsector,evenwithoutaccountingfortheavoidedcostsofenvironmentaldamages.Abatementpotentialviatechnicalmeasuresisalsolargeinthewastesectorandtoalesserextentinagriculture,whereitwillbedifficulttogreatlymitigateemissionswithoutchangingdietsattheglobalorregionallevels.▶Availablenet-negativeorlow-costtechnicalmitigationmeasuresalonecouldreduceanthropogenicmethaneemissionsbyapproximately20percentby2030,whereasalltargetedmeasurescouldreduceemissionsbyaboutonethird.Additionalmeasures,suchasswitchingfromnaturalgastorenewables,dietarychangesandfoodwastereductioncouldadd15percenttothe2030mitigationpotential.Thisisconsistentwithmethanereductionsinmost2°Cand1.5°Cpathways,whichareapproximately34percentand44percent,respectively,atthegloballevelin2030comparedto2015.▶CurrentNDCscoveronlyaboutonethirdofthemethanereductionrequiredtobeconsistentwitha2°Ctemperaturegoal,andonlyabout23percentofwhatisneededforthe1.5°Cgoal.Thereare,however,excellentopportunitiestoincludeadditionalmethanereductionmeasuresinNDCs,asseveralcountriesarealreadydemonstrating,forexamplethroughactionssuchasupstreamleakdetectionandrepairinoilandgassystems,eliminationofgasflaring,energyrecoveryfromlandfillgas,andreducingfoodwasteandloss.▶Actionisoftenhamperedbythefactthatreportedmethaneemissionsarehighlyuncertaingiventhelargenumberandcomplexityofemissionsourcesandtheuncertaintyoveremissionfactors.Recentdevelopmentsinmeasurementcapabilitiesenabletotalemissionsratestobemonitored,includingatthefacilityscaleforlargeremissionsources.Althoughthesemeasurementswillprovideamuchbetterbasisfordecisiveactions,theyneedtobeusedsystematicallyandtobecomeakeyelementinpreparingnationalpolicies.10.Carbonmarketscandeliverrealemissionsabatementanddriveambition,butonlywhenrulesareclearlydefined,designedtoensurethattransactionsreflectactualreductionsinemissions,andsupportedbyarrangementstotrackprogressandprovidetransparency.▶Article6oftheParisAgreementandinternationalmarketsarenotadirectsourceofambitionbutcanfunctionasaleverforimplementingandunlockinggreaterambition.Marketscanprovideanopportunityforcountries,companiesandotheractorstoachievetheiremissionreductiongoalsatlowercostsandtherebycreateroomtoenhancetheirambitioninboththenear-andlongterm.Particularly,participantswithhard-to-abateemissionswouldbeenabledtomeettheirmitigationgoalsatlowercosts.▶Fromamarket-integrityperspective,theoptimalsituationwouldbeforNDCstocomewithcomprehensiveGHGcoverage,clearlyquantifiablemitigationgoals,androbustaccounting,butNDCsarecurrentlyveryheterogeneous.Thiscreateschallengesfordevelopingarobustinternationalmarket.Theagreedrulesneedtoensureenvironmentalintegrityandencourageenhancedambition.AglobalmarketsystemwouldbestfacilitateprogresstowardsmeetingtheParisgoals,ifcountriesarenotallowedtocapturethebenefitsoflowercostwithoutraisingambition,orifcountriesthataresellingoffcheapmitigationoptionssubsequentlyensuredeliveryonthecostlierones.▶Theuseofmarketmechanismscouldhaveimportantimplicationsforbothmitigationandsustainabledevelopmentpathways.Inadditiontopotentiallyloweringthecostofadditionalambitioneverywhere,marketscouldleadtoashiftincapitalinvestmenttowardssellingregions,andinthiswayaffectmetricssuchaslocalairquality,employmentandsustainability,andshiftcosts.Nevertheless,thereisariskthatthiscouldleadtoreducedincentivesfortechnologicalinnovationinbuyingregions.▶GlobalmodellingstudiesestimatethatifallNDCsweretransformedintotradableemissionsabatementandallcountrieshadeconomy-widetargets,around4–5GtCO2ecouldbetradedperyearby2030.Ifthesavingsfrommorecost-XXIXEmissionsGapReport2021:TheHeatIsOneffectiveglobalimplementationofNDCswereredeployedtowardsincreasedambition,theemissionsreductionsplannedincurrentNDCscouldberoughlydoubledoverthenextdecadeatnoaddedcosttoparties,comparedtopartiesactingalonetoimplementtheircommitments.▶Thesestudiesindicatethesignificanttheoreticalpotentialofcarbonmarkets.Forthispotentialtoberealized,thesetheoreticalfindingsneedtobetranslatedintoreal-worldpolicychanges.ThechallengeforCOP26negotiationsistodecideonthenecessaryguidanceforarticle6thatcanlaunchaglobalmarketthatisabletograduallyexpandandimproveaspledgesevolveandexperiencesaregained.▶ThenumberofcountriesthatintheirneworupdatedNDCshaveindicatedtheplannedorpossibleuseofvoluntarycooperativeapproacheshasalmostdoubledcomparedtothepreviousNDCs,indicatingsignificantlyincreasedinterest.▶Formarketstoplayaroleintheprocesstowardsnet-zeroemissions,NDCsshouldcoverallsectorsandgasesandhaveeconomy-widequantitativegoals.Withnarrowingcostdifferencesovertime,thevolumeoftradingwouldlikelydiminish,whilethetransactionalvaluewouldincrease.ThemarketwouldincreasinglyfocusonCO2removalfromtheatmosphere.1EmissionsGapReport2021:TheHeatIsOnIntroductionAuthors:AnneOlhoff(UNEPDTUPartnership),JohnChristensen(CONCITO[Denmark’sclimatethinktank])11.1ContextoftheEmissionsGapReport2021ThistwelftheditionoftheUnitedNationsEnvironmentProgramme(UNEP)EmissionsGapReportcomesduringayearofconstantremindersthatclimatechangeisnotinthedistantfuture.Extremeweathereventsaroundtheworld–includingflooding,droughts,wildfires,hurricanesandheatwaves–havecontinuouslyhitthenewsheadlines.Thousandsofpeoplehavebeenkilledordisplacedandeconomiclossesaremeasuredinthetrillions.Bearingwitnesstotheincreasinglyclearsignsofclimatechange,theIntergovernmentalPanelonClimateChange(IPCC)publishedthefirstreportinitsSixthAssessmentcycleaddressingthe“PhysicalScienceBasis”inAugust2021.Dubbeda“coderedforhumanity”bytheUnitedNationsSecretary-General,theIPCCreportdocumentsinfargreaterdetailandwithhighercertaintythanpreviousassessmentshowclimatechangeandextremeeventscanbeattributedtothebuild-upofanthropogenicgreenhousegas(GHG)emissionsintheatmosphere.Thereisafifty-fiftychancethatglobalwarmingwillexceed1.5°Cinthenexttwodecades,andunlessthereareimmediate,rapidandlarge-scalereductionsinGHGemissions,limitingwarmingto1.5°Coreven2°Cbytheendofthecenturywillbebeyondreach.BuildingonthenewevidencefromtheIPCC,thetwenty-sixthUnitedNationsClimateChangeConferenceoftheParties(COP26)ischargedwiththegrowingurgencyofacceleratingglobalambitionandactiononbothmitigationandadaptation.Thiscoincideswithanimportantmilestoneinthefive-yearambition-raisingcycleoftheParisAgreement,wherebycountrieswererequestedtosubmitneworupdatednationallydeterminedcontributions(NDCs)thatrepresentaprogressioncomparedwithpreviousNDCsbeforeCOP26.Thereisthereforeaspecialfocusbothintheinternationaldiscussionsandinthisyear'sEmissionsGapReportontheambitionlevelinthenewandupdatedNDCs.AstheSeptember2021versionoftheNDCSynthesisReportpublishedbytheUnitedNationsFrameworkConventiononClimateChange(UNFCCC)illustrates,thenewandupdatedNDCsareinsufficienttoachievethetemperaturegoaloftheParisAgreement(UnitedNationsFrameworkConventiononClimateChange2021).ThisEmissionsGapReportconfirmsthefindingsoftheUNFCCCreport.ItexpandstheanalysistoconsiderneworupdatedNDCsandmitigationpledgesthathavebeenannouncedfor2030andassessestheimpactsoftheseonglobalemissions,theemissionsgapandprojectedglobalwarmingattheendofthecentury.Furthermore,itprovidesanin-depthassessmentofthenet-zeropledgesthatanincreasingnumberofcountriesarecommittingto,includingwhether2030planssetcountriesonaclearpathtowardstheirlonger-termnet-zeropledges.1.2Focus,approachandstructureofthereportEachyear,theEmissionsGapReportprovidesanupdatedassessmentofthegapbetweeni)estimatedfutureglobalGHGemissionsifcountriesimplementtheirclimatemitigationpledgesandii)theglobalemissionlevelsfromleast-costpathwaysthatarealignedwithachievingtheParisAgreementgoaloflimitingglobalwarmingtowellbelow2°Candpursuing1.5°C.Thisdifferencebetweenwherewewilllikelybeandwhereweneedtobeisnowwellknownasthe‘emissionsgap’.Thisyear,theneworupdatedNDCsaswellasofficiallyannouncedmitigationpledgesfor2030,withacut-offdateof30September2021,areincludedintheassessment.OneoftheUnitedKingdom’skeygoalsforitsCOP26presidencyistosecureglobalnetzerobymid-centuryandkeep1.5°Cwithinreach(UnitedNationsandUnitedKingdomundated).Todate,49countries(50parties,includingtheEuropeanUnion)havefirmlypledgednet-zeroemissiongoalsbyaroundmid-century,andalargenumberofnon-stateactorshavejoinedtheHigh-LevelClimateChampionsintheRaceToZerocampaignthataimstoelevateambitionandmobilizecredibleclimateactionamongcities,regions,businessesandinvestors.Giventheincreasingimportanceofandattentiontonet-zeroemissionpledges,thereportincludesaspecialchapteronnetzerowhichassessesthetrendsinandrobustnessofthesegoals,includingwhether2030commitmentssetcountriesonaclearpathtowardstheirlonger-termnet-zeropledges.2EmissionsGapReport2021:TheHeatIsOnThereportalsoincludesthreechaptersonopportunitiestobridgetheemissionsgapthatarepertinenttothecurrentglobalsituationandtheCOPnegotiations.First,anupdatedassessmentisprovidedontheextenttowhichCOVID-19fiscalrecoverymeasuresareusedtoaccelerateagreentransition.Second,thescopeforreducingemissionsfrommethane,thesecondlargestGHG,tobridgethegapandgetontracktowardsnetzeroisexamined.Finally,thereportlooksintoakeynegotiationissueforCOP26:reachingagreementonhowtomoveforwardwitharticle6oftheParisAgreementdealingwithcooperativeapproachesandmarketmechanisms.AlargenumberofcountrieshaveincludedtheuseofmarketmechanismsintheirNDCimplementationplansandarewaitingforthemodalitiestobeagreed.Asinpreviousyears,this2021EmissionsGapReporthasbeenpreparedbyaninternationalteamconsistingof78leadingscientistsfrom44expertinstitutionsacross24countries,assessingallavailableinformation,includingthatpublishedinthecontextoftheIPCCreports,aswellasinotherrecentscientificstudies.Thetransparentandparticipatoryassessmentprocesshasbeenoverseenbyanexperiencedsteeringcommittee.Allchaptershaveundergoneexternalreviewandtheassessmentmethodologyandpreliminaryfindingsweremadeavailabletothegovernmentsofthecountriesspecificallymentionedinthereportinordertoprovidethemwiththeopportunitytocommentonthefindings.Thereportisorganizedintosevenchapters,includingthisintroduction.Chapter2assessesthetrendsinglobalGHGemissionsandhowtheyareaffectedbyCOVID-19,andprovidesaglobalandG20-member-specificoverviewofnew,updatedandannouncedNDCs.Chapter3providesanassessmentofnet-zeroemissionpledges.Chapter4updatestheassessmentofthelikelyemissionsgapin2030,basedonneworupdatedNDCsaswellasofficiallyannouncedmitigationpledgesfor2030.Thechapterthenlooksattheimplicationsoftheemissionsgaponthefeasibilityofachievingthelong-termtemperaturegoaloftheParisAgreement.Chapter5assessestheextenttowhichCOVID-19fiscalrescueandrecoverymeasurestodatecansupportlow-carbonorhigh-carbondevelopment.Italsolooksatthedisparitiesbetweenhigh-incomeanddevelopingcountries.Chapter6assessestheroleofmethaneintheNDCsandinbridgingtheemissionsgap,andconsidersoptionsforcost-effectivereductionsoftheotherwisegrowingemissionsofmethane.Finally,chapter7looksatthepotentialroleofmarketmechanismsinimplementingNDCsandenhancingfutureambitions,anddiscusseswhatisrequiredtomaketheuseofmarketsenvironmentallyeffective,transparentandcredible.3EmissionsGapReport2021:TheHeatIsOnTrendsinglobalemissions,newpledgesfor2030andG20statusandoutlookLeadauthors:TakeshiKuramochi(NewClimateInstitute,Germany),MicheldenElzen(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),TarynFransen(WorldResourcesInstitute,USA),GlenPeters(CentreforInternationalClimateResearch[CICERO],Norway)Contributingauthors:AndrzejAncygier(ClimateAnalytics,Germany),AyşeCerenSarı(SHURA,Turkey),AnnaChapman(ClimateAnalytics,Australia),MonicaCrippa(JointResearchCentre[JRC],Italy),MengpinGe(WorldResourcesInstitute,USA),JohannesGütschow(PotsdamInstituteforClimateImpactResearch,Germany),MarianaGutierrez(IniciativaClimatica,Mexico),DiegoGuizzardi(JRC,Italy),GaheeHan(SolutionsForOurClimate,RepublicofKorea),LouiseJeffery(NewClimateInstitute,Germany),KimonKeramidas(JRC,Spain),CarolineLee(CanadianInstituteforClimateChoices,Canada),EnriqueMaurtuaKonstantinidis(FundaciónAmbienteyRecursosNaturales[FARN],Argentina),VictorMaxwell(ClimateAnalytics,Australia),MalteMeinshausen(UniversityofMelbourne,Australia),MarilenaMuntean(JRC,Italy),LeonardoNascimento(NewClimateInstitute,Germany),JosOlivier(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),MarkRoelfsema(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),EfisioSolazzo(JRC,Italy),HajimeTakizawa(InstituteforGlobalEnvironmentalStrategies,Japan),KentaroTamura(InstituteforGlobalEnvironmentalStrategies,Japan),HeleenvanSoest(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),JorgeVillareal(IniciativaClimatica,Mexico),SachiVohra(TheEnergyandResourcesInstitute[TERI],India),LisaWijayani(InstituteforEssentialServicesReform[IESR],Indonesia),WilliamWills(EosEstratégia&Sustentabilidade,Brazil),RyanWilson(ClimateAnalytics,Germany)22.1IntroductionThischapterreviewsthecurrentstatusofglobalgreenhousegas(GHG)emissionsaswellastheoutlookfor2030emissionsunderneworupdatednationallydeterminedcontributions(NDCs)andannouncedmitigationpledges.Italsoreviewsprogresstowardsimplementing2030pledges,withaspecialfocusonG20members.1Section2.2providesanoverviewofcurrenttrendsintotalglobalGHGemissionsandglobalcarbondioxide(CO2)emissionsfromfossilfueluseandindustry-relatedsources,consideringtheimpactofCOVID-19on2020and2021emissions.Section2.3presentsneworupdatedNDCscommunicatedundertheParisAgreement,aswellasadditionalpledgesfor2030thatareyettobeformallysubmittedasNDCs.Itdiscussesthecharacteristicsofthesepledges(inaggregate)andassessestheirimpact1ThemembersoftheG20are:Argentina,Australia,Brazil,Canada,China,France,Germany,India,Indonesia,Italy,Japan,Mexico,theRepublicofKorea,theRussianFederation,SaudiArabia,SouthAfrica,Turkey,theUnitedKingdom,theUnitedStatesofAmericaandtheEuropeanUnion.2TheUnitedKingdomhaslefttheEuropeanUnionbutwasinatransitionperioduntiltheendof2020,duringwhichtheEuropeanUnion’sNDCstillappliedtothecountry.onglobalandG202030emissions.Section2.4presentsG20members’pledges,assessingwhetherandhowtheyhavebeenupdated,alongwithprogresstowardstheirimplementation.TheassessmentcoversallindividualG20membersandregions,exceptEuropeanUnionmemberstates.2Thecut-offdatefortheassessmentsofneworupdatedNDCswassetas30September2021.ForthisEmissionsGapReport,progresstowardsachievingtheCancunPledgeshasnotbeenassessed,duetothelargeuncertaintyaround2020emissionsasaresultoftheCOVID-19pandemic.AmorecomprehensiveassessmentontheachievementoftheCancunPledgesisexpectedintheEmissionsGapReport2022.AllGHGemissionfiguresinthisreportareexpressedusingthe100-yearglobalwarmingpotentials(GWPs)fromtheIntergovernmentalPanelonClimateChange(IPCC)4EmissionsGapReport2021:TheHeatIsOnFourthAssessmentReport,3unlessotherwisenoted.Intermsofhistoricalemissionsdata,section2.2usesgloballyconsistentandindependentdatasetsratherthanofficiallyreportedUnitedNationsFrameworkConventiononClimateChange(UNFCCC)inventoryreports,whereassections2.3and2.4useUNFCCCinventoryreportswhencomparinghistoricalemissionstoindividualG20members’NDCtargets.Themethodologyandpreliminaryfindingsofthischapterweremadeavailabletothegovernmentsofthecountriesspecificallymentionedtoprovidethemwiththeopportunitytocommentonthefindings.2.2Currentglobalemissions:statusandtrendsAtpresent,therearenoestimatesavailableoftotalglobalGHGemissionsfor2020.However,theCOVID-19pandemicledtoanunprecedented5.4percentdropinCO2emissionsin2020(figure2.1),withasmallerdropintotalGHGemissionsexpectedfortheyear.From2010to2019,GHGemissionsgrewby1.3percentperyearonaverage,bothwithandwithoutland-usechange(LUC).GHGemissionsreachedarecordhighof51.5gigatonsofCO2equivalent(GtCO2e)in2019withoutLUCemissionsand58.1GtCO2ewhenincludingLUC4(figure2.1).These2019estimatesofglobalGHGemissionshavebeendownwardadjustedcomparedwiththeEmissionsGapReport2020,asmorecompletedatahavebecomeavailable.3Thischangewasmadetobemoreinlinewiththedecisionsofthetwenty-fourthUnitedNationsClimateChangeConferenceoftheParties(COP24)heldinKatowice,wherepartiesagreedtouseGWPsfromtheIPCCFifthAssessmentReportforreportingreasons.However,afullswitchtousingFifthAssessmentReportGWPsinthisreportisnotyetpossibleastheliteratureisstillnotuptodateonthisdecision.4TheGHGemissionsdatainthisreportarebasedontheEmissionsDatabaseforGlobalAtmosphericResearch(EDGAR;Crippaetal.2021),PBLNetherlandsEnvironmentalAssessmentAgency(OlivierandPeters2021)andLUCfromtheGlobalCarbonProject(Friedlingsteinetal.2020).EDGARdataareavailableuntil2020forCO2,butonlyuntil2018fornon-CO2emissions.Non-CO2emissionswereextrapolatedto2019basedontheEmissionsGapReport2020.GWPswereusedfromtheIPCCFourthAssessmentReport.Allestimatesfor2019and2020shouldbeconsideredpreliminary.DifferentGHGsplaydifferentrolesinthechangesintotalGHGemissions(figure2.1).FossilCO2emissionsdominatetotalGHGemissionsincludingLUC(66percentsince2010),aswellasthegrowthinGHGemissions.FossilCO2emissionsreachedarecord37.9GtCO2in2019,butdroppedto36.0GtCO2in2020.CO2emissionsfromLUChaveconstituted10percentofcumulativeGHGemissionssince2010,andcanchangesignificantlyfromyeartoyearduetoclimateconditions(Friedlingsteinetal.2020;Canadelletal.2021).EstimatesinthischapteronlyconsiderthedirecteffectsofLUCandrepresenttheaverageofthreebookkeepingmodels(Friedlingsteinetal.2020).Furthermore,theestimatesassumethat2020emissionsaresimilartothe2010–2019average,basedonpreliminaryestimatesoffiredata.Nopreliminaryestimatesareavailableforthegrowthofnon-CO2emissionsin2020.5EmissionsGapReport2021:TheHeatIsOnFigure2.1.Globalgreenhousegasemissionsfromallsources,1970–2020202020152010200520001995199019851980197519700605040302010CH4LULUCFCO2FossilCO2N2OF-gases2020dataonlyavailableforfossilandLULUCFCO2Globalgreenhousegasemissions(GtCO2e)Notes:LULUCF–landuse,land-usechangeandforestry.EDGARdatawereuseduntil2018formethane,nitrousoxideandfluorinatedgases,butwereextrapolatedto2019usinggrowthratesfromthepreviousversionofEDGAR(publishedintheEmissionsGapReport2019).Sources:EDGAR–Crippaetal.(2021);OlivierandPeters(2021);LUC–Friedlingsteinetal.(2020)Asmentionedpreviously,theCOVID-19pandemicledtoanunprecedenteddeclineinfossilCO2emissionsin2020,bothinrelativeandabsoluteterms.GlobalfossilCO2emissionsfell5.4percentaccordingtothisreport’sdataset,withotherestimatessuggestingdeclinesof5.8percent(GlobalCarbonProject,updatedbasedonFriedlingsteinetal.2020),5.8percent(excludingcement)(InternationalEnergyAgency[IEA]2021)and6.3percent(BP2021,excludingcement).ThechangeinfossilCO2emissionsvariedacrosscountries.Despitethepandemic,ChinesefossilCO2emissionsgrew1.3percentin2020,thoughmostothermajoremitterssawadeclineinemissions,includingtheUnitedStatesofAmerica(10percent),theEU27(10percent),India(6.2percent),withinternationaltransportation(shippingandaviation)droppingby20percent.Astrongreboundinemissionsisexpectedin2021(figure2.2).InApril2021,theInternationalEnergyAgency(IEA)estimateda4.8percentincreaseinemissionsin2021,afterthe5.8percentdeclinein2020(IEA2021).CarbonMonitor(Liuetal.2020)estimatesnearreal-timeestimatesofdailyCO2emissions,andbasedondatafromJanuarytoJuly2021,globalfossilCO2emissionsareonlyslightlylower(1percent)thanthesameperiodin2019.Ofthemajoremitters,onlyBrazil,ChinaandtheRussianFederationshowanincreaseinemissionsfromJanuarytoJuly2021relativeto2019.BasedontheIEAandCarbonMonitordata,fossilCO2emissionsareexpectedtohaveanearfullrecoveryin2021,withemissionlevelsonlyslightlylowerthantherecordhighin2019.6EmissionsGapReport2021:TheHeatIsOnFigure2.2.Changeinemissionsin2020and2021,bothrelativeto2019levelsduetoCOVID-19lockdowns2020/20192021/20190%-20%10%-10%5%-5%-25%-15%BrazilChinaEU27FranceGermanyIndiaItalyJapanRestofworldRussianFederationSpainUKUSAWorldSource:Liuetal.(2020)5Allfigurespresentedinsection2.3reflectneworupdatedNDCssubmitteduntil30September2021.DespitethelargedeclineinCO2emissionsin2020,theconcentrationofCO2intheatmospheregrewbyaround2.3partspermillion,inlinewithrecenttrends.Itisunlikelythatthereductionsinemissionsin2020willbedetectibleintheatmosphericgrowthrateforthreereasons.First,althoughemissionlevelsdeclined,theywerestillhighandaroundthesamelevelsasthoseseenintheearly2010s,meaningtheamountofCO2remainingintheatmosphereisexpectedtobeonlymarginallylessthanifemissionsgrew.Second,CO2isacumulativepollutantwithalonglifetime,sosustainedemissionreductionsareneededtoseeachangeintheatmosphericsignal.Finally,thenaturalvariabilityofaroundonepartpermillionisfargreaterthantheeffectofa5.4percentreductioninemissions.Similarfactorsmeanthatmethaneandnitrousoxideconcentrationsalsocontinuedtogrowinlinewithtrends,withtheincreaseintheseconcentrationsin2020thehighesteverrecorded.Thelackofchangeinatmosphericconcentrationsdespitearecorddropinemissionshighlightsthatsolvingtheclimateproblemrequiresrapidandsustainedreductionsinemissions.2.3TrendsandimplicationsoftheneworupdatedNDCsandotherannouncedmitigationpledgesfor20302.3.1GlobalsummaryoftrendsintheneworupdatedNDCsThedecisiontextthataccompaniedtheParisAgreement(1/CP.21)requestedthatpartieswhoseintendednationallydeterminedcontributions(INDCs)containedatimeframeupto2025communicateanewNDC,andthatpartieswhoseINDCcontainedatimeframeupto2030communicateorupdatethatcontributionby2020.Asat30September2021,5121parties(includingtheEuropeanUnionandits27memberstates,whichsubmitasingleNDC),representingaround52percentof2018globaldomesticGHGemissions(ClimateWatch2021),hadsubmitted94neworupdatedNDCs.TheNDCscommunicatedthusfarreflectemergingtrendsrelatedtotheambition,form,coverageand7EmissionsGapReport2021:TheHeatIsOnconditionalityofGHGmitigationpledges,aswellastheexpecteduseofmarketmechanismsintheirachievement.Effecton2030emissions:Ofthe94neworupdatedNDCs,justunderhalf(46NDCsfromcountriesrepresenting32percentofglobalGHGemissions)wouldresultinlower2030emissionsrelativetothepreviousNDCs(figure2.3).Eighteenpercent(17NDCsfromcountriesrepresenting6ThesefiguresincludeonlythosecountriesthathavesubmittedneworupdatedNDCs.13percentofglobalGHGemissions)hadcommunicatedaneworupdatedNDCthatwouldnotreduce2030emissionsrelativetothepreviousNDCs.Thirty-fourpercent(32NDCsfromcountriesrepresenting7percentofglobalemissions)couldnotbecomparedwiththepreviousNDCsintermsof2030emissions,typicallyduetoinsufficientinformationinthepreviousNDCs,astransparencyhasimprovedinthecurrentNDCs.Figure2.3.Effectofneworupdatednationallydeterminedcontributionson2030greenhousegasemissionsrelativetopreviousnationallydeterminedcontributionsNeworupdatedNDCwithlower2030emissionsthanpriorNDCNeworupdatedNDCnotcomparabletopriorNDCNeworupdatedNDCwithequalorhigher2030emissionsthanpriorNDCNoneworupdatedNDCsubmittedSource:ClimateWatch(2021)Pledgeform:OftheneworupdatedNDCs,more(89percent)haveGHGtargetsthanbefore(75percent).6ThesecompriseseveraltypesofGHGtargets,includingbase-yeartargets(commitmentstoreduceorcontroltheincreaseinemissionsbyaspecifiedamountrelativetoabaseyear)andbaselinescenariotargets(commitmentstoreduceemissionsbyaspecifiedamountrelativetoaprojectedemissionsbaselinescenario),amongotherformulations.Base-yeartargetstypically(thoughnotalways)resultinemissionsdecreasingovertimerelativetohistoricallevels,whereasbaselinescenariotargetsaretypically(thoughnotalways)formulatedtoallowabsoluteemissionstocontinuetogrow.TheformofGHGtargetsinneworupdatedNDCsevolvedrelativetothepreviousround,withaslightlylargershareofNDCsnowsettingbase-yeartargets(from19percentto28percentofNDCs).MostcountriesadoptingaGHGtargetforthefirsttimeintheirneworupdatedNDCadoptedabaselinescenariotarget.Sectorandgascoverage:GHGtargetscanbeformulatedtocoveracountry’sentireeconomyoronlyasubsetofit.Targetswithfullcoverageincludetheenergy,industrialprocessandproductuse,wasteandlandsectors,aswellasCO2,methane,nitrousoxide,hydrofluorocarbons(HFCs),perfluorochemicals(PFCs),sulfurhexafluorideandnitrogentrifluoride.TheGHGtargetsinthecurrentroundofNDCsareonlymarginallymorecomprehensiveintermsofsectorandgascoveragethaninthepreviousround.OftheneworupdatedNDCs,19percenthadfullsectorandgascoverage,upfrom14percentinthosecountries’firstNDCs.While8EmissionsGapReport2021:TheHeatIsOnsevencountriesimprovedtheirNDCsfrompartialcoveragetofullornearlyfullcoverage,threecountriesdowngradedtheirNDCsfromnearlyfullcoveragetopartialcoverage.Conditionality:SomepartieshavesubmittedNDCsthatareentirelyorpartiallyconditionalonfactorssuchasinternationalsupport(e.g.financeortechnologytransfer),whileothershavesubmittedNDCsthatarenotconditional.ThisroundofNDCsincludesmoreunconditionalelementsthanthelastround,with26percentcompletelyunconditional,upfrom24percentincountries’firstcontributions.ThiswaslargelyduetocountriesmakinganymixedconditionalandunconditionalelementscompletelyunconditionalintheirneworupdatedNDCs.Likewise,theshareofcompletelyconditionalNDCsfellfrom31percentto18percent.Finally,partiesareincreasinglyrecognizinggenderintegrationasameanstoenhancetheambitionandeffectivenessoftheirclimateactionintheirneworupdatedNDCs(UnitedNationsFrameworkConventiononClimateChange[UNFCCC]2021).2.3.2ImpactsonGHGemissionsby2030attheglobalandG20levels,consideringneworupdatedNDCsandannouncedmitigationpledgesThissectionquantifiestheimpactsoftheneworupdatedNDCsandannouncedmitigationpledgesonglobal2030emissions,relativetothepreviousNDCs.TheanalysisisbasedonthedifferenceinprojectedGHGemissionsby2030underthefullimplementationoftheneworupdatedNDCsubmissionsandannouncedpledgescomparedwiththepreviousNDCs.Thedataarefromfivemodelgroupsandtwoopen-sourcetools.7,8AggregateimpactonglobalGHGemissionsin2030TheanalysisshowsthattheaggregateimpactoftheneworupdatedunconditionalNDCsisestimatedtoleadtoareductionin2030globalGHGemissionsofabout2.9GtCO2e,comparedwiththepreviousNDCs(figure2.4).Thisestimateincludesreductionsofaround0.3GtCO2eresultingfromotherfactors,includinglowerprojectionsofinternationalaviationandshippingemissions,andadjustmentsofcountriesthatareprojectedtooverachievetheirNDCtargets.IftheannouncedpledgesofChina,JapanandtheRepublicofKoreaareincluded,thisreductionincreasesto4.1GtCO2e.Fortheconditionaltargets,thesereductionsare2.8GtCO2eand4.0GtCO2e,respectively.7ClimateActionTracker(2021a;2021b);JointResearchCentrewiththeProspectiveOutlookonLong-termEnergySystems(POLES)model(JointResearchCentre2021);PBLNetherlandsEnvironmentalAssessmentAgencywiththeIntegratedModeltoAssesstheGlobalEnvironment(IMAGE)model(denElzenetal.2021,inpreparation;Nascimentoetal.2021).Thetwoopen-sourcetoolsthatprovideNDCemissionsprojectionsformanycountriesare:ClimateResource(Meinshausenetal.2021)andtheWorldResourcesInstitute’sClimateWatch(2021).AllGHGemissionsprojectionsoftheClimateActionTrackerandClimateResourceexcludeLULUCF.8Thefollowingdatasourceshavebeenusedtoassessannouncedpledgesthathavenotyetbeenformallysubmitted:ClimateActionTracker,PBLandtheJointResearchCentre.ClimateActionTrackeraccountsfortheimpactoftheannouncementsofChinaandJapan,JointResearchCentreforChinaandJapan,andPBLfortheimpactofChina,JapanandtheRepublicofKorea.9EmissionsGapReport2021:TheHeatIsOnFigure2.4.Impactof2030pledges(nationallydeterminedcontributionsandotherannouncedpledgesasat30September2021)on2030globalemissionscomparedwithpreviousnationallydeterminedcontributionsubmissionsNon-G20OtherfactorsOtherfactorsTotalTotalMexicoSaudiArabiaIndonesiaChinaArgentinaSouthAfricaAustraliaTurkeyUSABrazilCanadaJapanEU27IndiaUKIncreasedemissionsReducedemissionsMtCO2e0-4000-3000-2000-1000500-500-4500-3500-2500-1500ImpactofannouncedpledgesTotalimpactRussianFederationRepublicofKoreaG20membersTakingacloserlookattheG20members,thecombinedimpactofsubmittedNDCsandannouncedGHGreductiontargetsfor2030isanannualreductionofabout3GtCO2ecomparedwiththepreviousNDCs.SixG20membershaveformallysubmittedupdatedNDCswithenhancedGHGmitigationpledges:Argentina,Canada,theEU27(countingtheEU27anditsthreeindividualG20memberstatesFrance,GermanyandItalyasone),SouthAfrica,theUnitedKingdomandtheUnitedStatesofAmerica–allofwhichentailreducedemissionsin2030ofabout2.1GtCO2ecomparedwithpreviousNDCs.TwoG20members(BrazilandMexico)havesubmittedtargetsthatleadtoanincreaseinemissionsof0.3GtCO2e,bringingthenetreductioninglobalGHGemissionsofneworupdatedNDCssubmittedbyG20membersto1.8GtCO2eannuallyby2030.Inaddition,China,JapanandtheRepublicofKoreahaveannouncedenhancedpledgesthatresultinannualreductionsofabout1.2GtCO2e,buthavenotyetformallycommunicatedthemtotheUNFCCC.ThelargestreductionscomefromtheUnitedStatesofAmerica,theEU27,theUnitedKingdom,ArgentinaandCanada(submitted),andChinaandJapan(announced).TwoG20members(AustraliaandIndonesia)havesubmittedNDCtargets,whichareassessednottoleadtoanadditionalreductionrelativetothepreviousNDCs.OneG20member(theRussianFederation)hassubmittedanNDCthatimprovesuponitspreviousNDC,butstilldoesnotgobeyonditscurrentpoliciesandanotherthreeG20members(India,SaudiArabiaandTurkey)havenotyetsubmittedaneworupdatedNDC(table2.1).Non-G20membersIncomparison,theaggregateimpactoftheneworupdatedNDCsubmissionsforthenon-G20membersisanannualreductionofabout0.8GtCO2eby2030.OtherfactorsFinally,additionalreductionsofaround0.3GtCO2ecomefromthedecreasedinternationalaviationandshippingemissionsprojections,andfromcountriesthatareprojectedtooverachievetheirNDCtargets.Asexplainedpreviously,forsomecountries,NDCemissionlevelsareexpectedtobeabovetheestimatedcurrentpoliciesscenario,withtheprojectionsofthecurrentpoliciesscenarioassumedfortheglobalemissionsestimate.DuetotheimpactonCOVID-19onGHGemissionsprojectionsunderthecurrentpoliciesscenario,theemissionsprojectionsofmanycountrieshavelowered.ThismeansthatalargernumberofcountriesareexpectedtooverachievetheirNDCtargets,inparticularIndia,theRussianFederationandTurkey,whichlowersglobalGHGemissions.Inaddition,themethodologyoftheunderlyingmodelsmayhavealsobeenupdated,whichcouldleadtochangesinglobalemissionsestimatesbetweenscenarios.10EmissionsGapReport2021:TheHeatIsOnTable2.1.SummaryofgreenhousegasmitigationpledgesinpreviousandneworupdatednationallydeterminedcontributionsbyG20membersG20memberOriginalNDCNeworupdated2030pledgeChangein2030emissionsrelativetooriginalNDCBasedonmodellingstudies(medianandrange)G20membersthathavesubmittedneworupdatedNDCsArgentinaCap2030netemissionsat483megatonsofCO2equivalent(MtCO2e)(unconditional)and369MtCO2e(conditional)Cap2030netemissionsat359MtCO2e(unconditional)-0.12GtCO2e(range:-0.11–-0.13)AustraliaReduceGHGemissionsby26–28percentfrom2005levelsby2030ReduceGHGemissionsby26–28percentfrom2005levelsby2030NochangeBrazilReduceGHGemissionsby37percentfrom2005levelsby2025and(indicatively)43percentfrom2005levelsby2030ReduceGHGemissionsby43percentfrom2005levelsby203090.3GtCO2e(range:0.15–0.4)CanadaReduceGHGemissionsby30percentfrom2005levelsby2030Emissions40–45percentbelow2005levelsby2030-0.09GtCO2e(range:-0.08–-0.1)EU27ReduceGHGemissionsbyatleast40percentfrom1990levelsby2030(appliedoriginallytoEU28collectively)ReducenetGHGemissionsbyatleast55percentfrom1990levelsby2030-0.6GtCO2e(range:-0.5–-0.7)IndonesiaReduceGHGemissionsby29percent(unconditional)and41percent(conditional)relativetobusinessasusual(BAU)by2030ReduceGHGemissionsby29percent(unconditional)and41percent(conditional)relativetoBAUby2030NochangeMexicoReduceGHGemissionsby22percent(unconditional)and36percent(conditional)fromBAUby2030ReduceGHGemissionsby22percent(unconditional)and36percent(conditional)fromBAUby2030MarginalincreaseduetochangeinBAUscenarioRussianFederationLimit2030emissionsto70–75percentof1990levelLimit2030emissionsto70percentof1990levelsReduced,butthetargetstillresultsinhigheremissionsthanthecurrentpolicyprojectionSouthAfricaLimit2025–2030emissionsto398–614MtCO2eLimit2030emissionsto350–420MtCO2eReduced9TheupdatedNDCleadstoanabsoluteincreaseinemissions.BothNDCspresentthesamereductiontargetof43percentby2030below2005emissionlevels.Brazil’sNDCemissions(andthereforetheabsoluteemissionsintheNDCscenario)varyagreatdealduetorevisionsofthe2005baseyear.Thecountry’ssecondandthirdinventoryreportsandFourthNationalCommunication(itslatest)givedifferentvalues.ThefirstNDCreferstothesecondinventoryreport,whiletheupdatedNDCcitesthe2005baseyearemissionsofthethirdinventoryreport(FifthAssessmentReviewmetrics),butalsospecifiesthat“informationonemissionsin2005andreferencevaluesmaybeupdatedandrecalculatedduetomethodologicalimprovementsapplicabletotheinventories”(Brazil2020).11EmissionsGapReport2021:TheHeatIsOnUnitedKingdomContributiontoEU28-wideemissionstarget:reductiontargetofatleast40percentReduceGHGemissionsbyatleast68percentfrom1990levelsby2030-0.17GtCO2e(range:-0.1–-0.2)UnitedStatesofAmericaReduceGHGemissionsby26–28percentfrom2005levelsby202510ReduceGHGemissionsby50–52percentfrom2005levelsby2030-0.85GtCO2e(range:-0.8–-0.9)11G20membersthathaveannouncedmitigationpledgesfor2030ChinaPeakCO2emissionsaround2030ReduceCO2/grossdomesticproduct(GDP)by60–65percentfrom2005levelsby2030Increasetheshareofnon-fossilfuelsinprimaryenergyconsumptiontoaround20percentby2030Increaseforeststockvolumebyaround4.5billionm3by2030PeakCO2emissionsbefore2030ReduceCO2/GDPby65percentfrom2005levelsby2030Increasetheshareofnon-fossilfuelsinprimaryenergyconsumptiontoaround25percentby2030Increaseforeststockvolumebyaround6billioncubicmetresin2030Increasetheinstalledcapacityofwindandsolarpowerto1,200GWby2030-0.8GtCO2e(range:-0.5–-1.2)JapanReduceGHGemissionsby26percentfrom2013levelsby2030ReduceGHGemissionsby46percentfromfiscalyear2013levelsbyfiscalyear2030,witheffortstoreduceby50percent-0.27GtCO2e(range:-0.17–-0.32)RepublicofKoreaReduceGHGemissionsby37percentfromBAUby2030ReduceGHGemissionsby35percentfrom2018levelsby2030ReducedG20membersthathavenotyetsubmittedneworupdatedNDCsorannouncedpledgesIndiaReduceemissions/GDPby33–35percentfrom2005levelsby2030Increasetheshareofnon-fossilfuelsinprimaryelectricityproductionto40percent(conditional)N/AN/ASaudiArabiaAnnuallyabateupto130MtCO2eby2030N/AN/ATurkeyReduceGHGemissionsbyupto21percentfromBAUby2030N/AN/ANotes:Australia’soriginalNDCwas‘tobedevelopedintoanemissionsbudget’overthe2021–2030period.TheupdatedNDCofDecember2020providedanindicativeemissionsbudgetof4,832–4,764MtCO2e.On31August2021,theNationalAssemblypassedtheFrameworkActonCarbonNeutrality,whichoutlinesthenew2030target(RepublicofKorea,MinistryofEnvironment2021).Thereisnostudyavailableyetthatcomparestheambitionofthenew2030targetwiththepreviousNDC.Sources:ClimateWatch(2021)10ForcomparisonwiththeupdatedNDC,modellingstudiesinterpolatetheprevious2025and2050targets(80percentfrom2005levels).11ClimateActionTracker(2021a)alsoreportsthecalculatedimpactrelativetothecurrentpoliciesscenario.AsthewithdrawaloftheUnitedStatesofAmericafromtheParisAgreementtookeffecton4November2020,thecountrynolongerhadanofficialNDCin2020.ThecalculatedimpactoftheupdatedNDCrelativetothecurrentpoliciesscenariowouldthereforebeareductionofabout2.0GtCO2e.12EmissionsGapReport2021:TheHeatIsOn2.4AssessmentofG20members’progresstowardsNDCsandmitigationpledgesfor2030ThissectionassessestheprogressofG20memberstowardstheirpreviousNDCtargetsandindicatesprogresstowardsnew,updatedorannounced2030targetsbasedonemissionsprojections.GHGemissionsprojectionswerecompiledandreviewedtoassesstheemissionlevelsexpectedforG20membersunderexistingpolicies,i.e.thecurrentpoliciesscenario,12andwhethermembersarelikelytomeettheirrespectiveemissionreductiontargetsfor2030.Projectionsofthecurrentpoliciesscenarioassumethatnoadditionalmitigationpoliciesandmeasuresaretakenbeyondthoseadoptedand/orimplementedasofacertaincut-offdate(denElzenetal.2019).Thisreport’sassessmentisbasedon‘point-in-time’emissionsprojectionsintheNDCtargetyear.2.4.1MethodsandlimitationsCurrentpoliciesscenarioprojectionswerecomparedagainsttheoriginalunconditionalNDCsatthetimeofpublicationoftheEmissionsGapReport2020(November2020),aspresentedintable2.1.ThisassessmentfollowsthemethodologyofdenElzenetal.(2019)toenablearobustcomparisonofprojectionspublishedbyindependentresearchinstitutions.EuropeanUnionmemberstatesareassessedastheEU27(andnotindividually),withtheUnitedKingdomnowassessedseparately.Officialassessmentspublishedbynationalgovernmentswerecomparedwithindependentassessments.AlldatasourcesarepresentedinappendixA(availableonline).Policycut-offdatesrangedfrom2017to2021acrossstudies.Theprogressassessmentwasbasedonemissionsfiguresincludinglanduse,land-usechangeandforestry(LULUCF;seeappendixAonhowtheemissionsprojectionsexcludingLULUCFwereadjusted).RecentlypublishedemissionsprojectionsforthecurrentpoliciesscenarioandNDCscenariowerecollectedfromindependentstudiesandconsidered.AsatOctober2021,onlyafewoftheinstitutionsregularlypublishingnational-levelCO2andGHGemissionsprojectionsforthecurrentpoliciesscenariohadreleasedupdatesthatconsideredthepotentialimpactofCOVID-19.Annuallypublishedglobalstudies,suchasClimateActionTracker(2021b),JointResearchCentreoftheEuropeanCommission(JointResearchCentre2021)andPBLNetherlandsEnvironmentalAssessmentAgency(Nascimentoetal.2021;PBLNetherlandsEnvironmentalAssessmentAgency2021),aswellasnationalstudies,suchastheRhodiumGroupstudyfortheUnitedStatesofAmerica(Pittetal.2021),allincludetheimpactofCOVID-19andrecentpolicies.Forthesestudies,theprogressassessment12Currentpolicyscenarioprojectionsassumethatnoadditionalmitigationactionistakenbeyondcurrentpolicies,evenifitresultsinNDCtargetsnotbeingachievedorbeingoverachieved(UnitedNationsEnvironmentProgramme[UNEP]2015;denElzenetal.2019).Currentpoliciesscenarioprojectionsreflectalladoptedandimplementedpolicies,whichforthepurposeofthisreportaredefinedaslegislativedecisions,executiveordersortheirequivalent.Thisimpliesthatofficiallyannouncedplansorstrategiesalonewouldnotqualify,whileindividualexecutiveorderstoimplementsuchplansorstrategieswouldqualify.13COMMIT–Climatepolicyassessmentandmitigationmodelingtointegratenationalandglobaltransitionpathways.usedNDCtargetemissionestimatesfromtheirpreviousupdates(usedintheEmissionsGapReport2020).OtherrecentstudiesincludedseveralnewnationalmodelscenariosfromFragkosetal.(2021)andtheCOMMIT13scenariodatabase(InternationalInstituteforAppliedSystemsAnalysis[IIASA]2021;vanSoestetal.2021)forAustralia,China(twonationalstudies),theEU27andtheUnitedStatesofAmerica.Thesestudiesupdatedsome2020nationalmodelscenarioprojectionsfromtheEuropeanHorizon2020LinkingClimateandDevelopmentPolicies–LeveragingInternationalNetworksandKnowledgeSharing(CD-LINKS)project(Roelfsemaetal.2020).However,itshouldbenotedthatthesescenariosdidnotincludetheimpactofCOVID-19.Afterexaminingtheprojectionsfromthestudiescollected,anumberofpre-2020studieswereexcludedwhose2020emissionestimatesweremorethan10percenthigherthanthehighestestimatesofthethreestudiespublishedin2021thatconsideredtheimpactofCOVID-19andrecentpolicies(ClimateActionTracker2021b;JointResearchCentre2021;Nascimentoetal.2021).Up-to-dateofficialemissionsprojectionspublishedsinceNovember2020werecollectedfromvarioussources,includingcountries’recentlypublishednationalcommunicationsandbiennialupdatereports,andothernationalgovernmentreports(seeappendixA).SuchinformationincludedannuallyupdatedprojectionsmadebytheAustralianandCanadiangovernments(Australia,DepartmentofIndustry,Science,EnergyandResources2020;Canada,EnvironmentandClimateChangeCanada2021).Themostimportantlimitationforthe2021assessmentistheimpactoftheCOVID-19pandemiconthecurrentpoliciesscenarioprojections.AsatSeptember2021,severalrecentprojectionshadeitherbeenpublishedorpreparedpriortothepandemic,andthereforedidnotaccountforitspotentiallysignificantimpactonemissiontrendsin2020and2021,andintheperioduntil2030.OtherimportantlimitationsaresimilartothoseofpreviousEmissionsGapReports(seeappendixA).2.4.2G20progresstowardspreviousNDCtargetsandindicationsofprogresstowardsnew,updatedorannouncedtargetsfor2030Collectively,theG20membersareprojectedtofallshortoftheirneworupdatedunconditionalNDCsandotherannouncedmitigationpledgesfor2030.Similarly,G20membersareprojectedtocollectivelyfallshortoftheirpreviousunconditionalNDCs(asatNovember2020)by1.1GtCO2eperyear,iftheunconditionalNDCsofthethreeG20membersthatareprojectedtosignificantlyoverachieve13EmissionsGapReport2021:TheHeatIsOntheirtargets(India,theRussianFederationandTurkey;seetable2.2)aresubstitutedwithcurrentpoliciesscenarioprojections.However,theG20membersarecollectivelyexpectedtoslightlyoverachievetheirpreviousunconditionalNDCsbyabout0.3GtCO2eperyearby2030,basedonscenarioprojectionsbyindependentstudies.Table2.2showstheprogressofG20memberstowardstheirpreviousNDCtargetsasofNovember2020,organizedbythestatusandassessmentoftheirneworupdatedNDCtargetsandotherannounced2030targetssubmittedorannouncedthereafter.Tenof1714G20membersarelikelytoachievetheirunconditionalNDCtargetsbasedonpreviousorfirstNDCsubmissionsundercurrentpolicies(i.e.Argentina,China,theEU27,India,Japan,theRussianFederation,Saudi14AnassessmentofindividualEuropeanUnionmemberstateswasnotconducted.Arabia,SouthAfrica,TurkeyandtheUnitedKingdom–asaformerEuropeanUnionmemberstate;seetable2.2).ThreeG20members(India,theRussianFederationandTurkey)areprojectedtobeatleast15percentlowerthantheirpreviousunconditionalemissiontargetlevelsandthereforehavesignificantroomtoincreasetheambitionoftheirNDCs(figure2.5).Centralestimatesofemissionsprojectionsfor2030undercurrentpolicieswerelowerthanthoseoftheEmissionsGapReport2020forallpreviouslymentionedG20members,withtheexceptionofArgentina,whoseestimateremainedlargelyunchanged.Forexample,fortheEU27andSouthAfrica,currentprojectionsareroughly10percentand20percentlowerthantheprojectionsoflastyear’sassessment,respectively,duetoenhancedpoliciesandtheimpactofCOVID-19.14EmissionsGapReport2021:TheHeatIsOnTable2.2.AssessmentofprogresstowardsachievingthepreviousunconditionalnationallydeterminedcontributiontargetsforG20membersundercurrentpoliciesbasedonindependentstudiesmainlypublishedaftertheCOVID-19outbreakProjectedprogresstowardsthepreviousNDCtarget[xstudiesmeetthetarget/outofystudies]Achieveprevioustarget(indicatedby+,ifoverachievedbymorethan15percent)MissprevioustargetUncertainStatusofNDCorannouncedtargetSubmittedstrongertargetArgentina[3/3],EU27[inEmissionsGapReport2020forEU27+UK;1/3,onewithinreach],1,2RussianFederation+[4/5],1SouthAfrica[3/3],UK(formerlypartoftheEU)USA[0/5],Canada[1/3]AnnouncedstrongertargetChina[4/6],Japan[3/3]RepublicofKorea[0/3]3NonewtargetsubmittedIndia+[4/6],SaudiArabia[2/2],Turkey+[3/3]SubmittedequivalentorweakertargetAustralia[1/4],Brazil[1/4,onewithinreach],Mexico[0/3]Indonesia[0/3,twowithinreach]Notes:SeeappendixAforthelistofstudiesreviewed.ThenumberofindependentstudiesthatprojectacountrytomeetitspreviousorfirstNDCtargetwerecomparedwiththetotalnumberofstudiesandareindicatedinsquarebrackets.‘Withinreach’indicatesthatonlythelowerboundestimateofthecurrentpoliciesscenarioiswithintheNDCtargetrange.1.Currentpoliciesscenarioprojectionswerealsoexaminedfromofficialpublications.Thenumberofofficialpublicationsthatprojectedcountrieswouldachievetheirpoint-in-timeNDCtargetwere:Australia:0of1,Canada:0of1,EU27:0of1,RussianFederation:0of1andtheUnitedKingdom:0of1.2.TheEUReferenceScenariowasusedfortheEU27,whichassumesfullimplementationofthenationalenergyandclimateplansbyEuropeanUnionmemberstatesandseesEuropeanUnionemissionsreducebyaround43percentbelow1990levelsby2030(EuropeanCommission2021).IncludingnetremovalsfromLULUCFincreasesthereductionto45percent.ThisbaselinescenarioindicatesthatadditionaleffortwouldberequiredtomeettheEuropeanUnion’scurrent2030energy-efficiencytarget,thoughitscurrent2030renewableenergytargetwouldbemet.Additionalmeasuresformemberstatesarebeingpreparedtofullyimplementnationalenergyandclimateplanssubmittedin2020(EuropeanCommission2020).3.TheRepublicofKorea’sEmissionsTradingScheme(K-ETS)isaninstrumentusedtofullyachievethecountry’sNDCtargetandcoversabout70percentofitsGHGemissions.Amongthethreeindependentstudies,onlyone(PBLNetherlandsEnvironmentalAssessmentAgency)explicitlyquantifiedtheimpactoftheK-ETSupto2025basedontheMasterPlansforK-ETSPhaseIII(2021–2025)andPhaseIV(2026–2030)andthePhaseIIINationalAllowancesAllocationPlan.ThispartiallyexplainswhythestudiesprojectthattheRepublicofKoreawillmissitsNDCtargetundercurrentpolicies.ForChina,fouroutofsixindependentstudiesprojectedthatthecountrywouldachieveitsoriginalNDCtarget.However,sincefiveofthesixstudiesreviewedonlyprovidedasingleNDCtargetvaluefor2030–despiteChina’sNDCcontainingmultipletargets,whicharepartlydependentonGDPgrowthrates–itwasnotpossibletoanalyseindetailwhichtargetswouldlikelybemetoroverachieved.Thelong-termimpactsofCOVID-19onGHGemissionswerealsohighlyuncertain,especiallygiventhefactthatChina’sfossilCO2emissionsreboundedstronglyinthesecondhalfof2020andin2021(section2.2).Thisstronger-than-expectedreboundwasnotconsideredinChina’slatestemissionsprojectionsthatestimatedtheimpactofCOVID-19(ClimateActionTracker(2021b),JointResearchCentre(2021)andPBLNetherlandsEnvironmentalAssessmentAgency(2021)).SixG20members’GHGemissionswereprojectedtofallshortandthereforerequirefurtheractionofvaryingdegreetomeettheirprevious(ororiginal)unconditionalNDCtargets.TheseG20membersareAustralia,Brazil,Canada,Mexico,theRepublicofKoreaandtheUnitedStatesofAmerica.15EmissionsGapReport2021:TheHeatIsOn▶ForAustralia,officialprojectionsshowedthatitwillfallshortofachievingitspoint-in-timetargetof26–28percentby2030withimplementedmeasures.Australiaisalsoprojectedtomissitsemissionsbudgettargetsfor2021–2030withoutrelyingonpastoverachievement(Australia,DepartmentofIndustry,Science,EnergyandResources2020).However,theofficialprojectionsalsoindicatedthatAustraliawouldachieveitspoint-in-timeNDCtargetifitsTechnologyInvestmentRoadmapisfullyimplemented(‘Hightechnology’scenario)(Australia,DepartmentofIndustry,Science,EnergyandResources2020).▶ForCanada,officialprojectionsindicatedthatifitsstrengthenedclimateplan,AHealthyEnvironmentandaHealthyEconomy,introducedinDecember2020,isfullyimplemented,itsGHGemissionswouldbereducedby31percentbelow2005levels,thusoverachievingitspreviousNDCtargetof30percentbelow2005levels(Canada,EnvironmentandClimateChangeCanada2021).▶ForMexico,allthreeindependentstudiesreviewedinthisassessmentshoweda(minor)increasein2030emissionsprojectionscomparedwithpreviousassessmentsincludedintheEmissionsGapReport2020,findingthatthecountrywouldnarrowlymissitsoriginalNDCtarget.▶TheUnitedStatesofAmericahasreturnedtotheParisAgreementandreversedmanypoliciesoftheTrumpAdministrationthatwouldhaveledtoincreasedemissions.Thecentralestimateforthecountry’s2030emissionsinthisyear’sassessmentdecreasedbyabout0.5GtCO2e/year(about10percent).Themainreasonsforthisresultincludetheexclusionoftwoprojectionsdevelopedwitha2017cut-offdateforpolicies(Chaietal.2017;Roelfsemaetal.2020),whichwerereplacedwithoneupdatednationalmodelprojectionoftheCOMMITscenariodatabase,andtheinclusionofprojectionsthatquantifiedthepotentialimpactoftheCOVID-19pandemiconemissionsin2020andbeyond,andtoalesserextentonthequantifiedimpactofthereversalofthepreviousAdministration’spolicies.15Thereareseveralotherfactorsfortheloweremissionsprojections,includingrevisionsinGHGinventorydataandchangesinemissionsscenariomethodologies,alongwithotherunderlyingassumptions.ItisworthnotingthatCanadaandtheUnitedStatesofAmericahavestrengthenedtheirNDCtargets,thoughindependentstudiessuggestthattheyarenotontracktomeettheirearlierNDCtargetswithimplementedpolicies.Althoughpositivetrendshavebeenobservedasdescribedpreviously,thesetwocountriesneedtomakesignificantadditionaleffortstomeettheirnewNDCtargets.IndependentstudieseitherdonotagreeorareinconclusiveonwhetherIndonesiaisontracktomeetitsunconditionalNDCs.ThisismainlyduetotheuncertaintyofLULUCFemissionsprojectionsasaresultofpeatfires.Thecentralestimatefor2030emissionsinthisyear’sassessmentarehigherthanthatofthe2020assessment,partiallyduetothemajorrevisionofLULUCFemissionsdataandprojections.TheaggregateemissionsforG20membersin2030undercurrentpoliciesareprojectedtobeabout2GtCO2elowerthanthatofthe2020assessment.Considerationof2020emissionreductionsandthelong-termimpactofCOVID-19ontheglobaleconomyhascontributedsignificantlytotheloweremissionsprojections.AnotherkeyfactorbehindtheseestimatedloweremissionsistheimpactofpoliciesadoptedbyG20membersinrecentyears,whichwillaffecttheirprogresstowardsachievingtheirNDCtargets.15AlistofkeypolicymeasuresthatmayhavesignificantdirectimpactsonfutureGHGemissionsadoptedin2020and2021arepresentedinappendixA.Manyofthesepolicieswereadoptedafterthepublicationofthescenariostudiesreviewedinthissection.Althoughtherehavebeenmanypositivedevelopments,therehavealsobeenseveralnegativeones,suchastheimplementationoffossilfuelextractionprojectsandcoal-firedpowerplantconstructionplans,aswellastherollbackofenvironmentalregulationsduringthepandemic.Basedonthecentralestimatesofindependentstudies,severalG20members,namelyArgentina,Brazil,China,India,Indonesia,Mexico,theRussianFederationandSaudiArabia,areexpectedtoemitmoreemissionsin2030thantheydidin2010underimplementedpolicies.Figure2.5providesamoredetailedoverviewofG20members’projectedGHGemissionsundervariousscenarios,whicharealsocomparedwithhistoricalemissions.16EmissionsGapReport2021:TheHeatIsOnFigure2.5.Greenhousegasemissions(allgasesandsectors,includinglanduse,land-usechangeandforestry)oftheG20anditsindividualmembersby2030underthecurrentpoliciesscenario,previousnationallydeterminedcontributionsandnew,updatedorannouncedpledgescomparedwithhistoricalemissionsFigure2.5a024681012141618ChinaEU27IndiaUSAEmissions(GtCO2e/yr)0.00.51.01.52.02.53.0ArgentinaAustraliaBrazilCanadaIndonesiaJapanMexicoRepublicofKoreaRussianFederationSaudiArabiaSouthAfricaTurkeyUKEmissions(GtCO2e/yr)3GtCO2e3GtCO2eHistoricaldatafromnationalinventoryreportfor2010Currentpolicies2030(independentstudies)UnconditionalNDC(previous)UnconditionalNDC(neworupdated)AnnouncedpledgeNotes:Forcurrentpoliciesscenarioprojections,estimatesbasedonindependentstudiesarepresented.ForNDCs,officialvalues(adjustedtoFourthAssessmentReportGWPs)arepresentedwhereavailable.Forreportingreasons,theemissionsprojectionsforChina,theEU27,IndiaandtheUnitedStatesofAmericaareshowninfigure2.5a,andtheothercountriesshowninfigure2.5b,usingtwodifferentverticalaxes.SeeappendixAfordetails.FortheUnitedStatesofAmerica’spreviousNDC,theaverageof2030estimatesfromtwostudiesareshown(JointResearchCentre2021;ClimateActionTracker2021b).ForChinaandSouthAfrica,theestimatedemissionsunderthenew2030announcedtargetsarebasedonClimateActionTrackerandPBLNetherlandsEnvironmentalAssessmentAgencystudies(Nascimentoetal.2021;ClimateActionTracker2021b).EstimatesforChina,JapanandtheRepublicofKoreauseannouncedtargets.Tosupplementthefindingspresentedabove,figure2.6presentspercapitaGHGemissionsunderthecurrentpoliciesscenario,NDCtargetsandotherannounced2030pledgesasat30September2021,aswellasthe2010historicalestimatesforthe17G20members(countingtheEU27anditsthreeindividualG20memberstatesasone).In2030,theaveragepercapitaemissionsofG20membersunderlatestNDCsandotherannounced2030pledgesareprojectedtobeslightlylower(7tCO2e)thanunderthecurrentpoliciesscenario(7.4tCO2e)andthepreviousNDCs(7.2tCO2e).However,comparedwith2010levels,averageemissionsarenotexpectedtobelowerandasthefigureillustratestheyarestillfaroffthemedianestimatesconsistentwith2°Cand1.5°Cscenariosby2050,whichare1.9tCO2e(tenthFigure2.5b17EmissionsGapReport2021:TheHeatIsOnandninetiethpercentilerange:1.2–2.3tCO2e)and0.6tCO2e(0.3–1.1tCO2e),respectively.16PercapitaemissionsvarysignificantlyacrossG20members,withIndia’semissionsabouthalftheG20averageforexample,andSaudiArabia’sthreetimesgreater.TheEU27andtheUnitedKingdomperformwellinbothabsoluteandpercapitaemissionlevelsby2030andtheirreductionratescomparedwith2010levels.AustraliaandSouthAfricaarealsoprojected16EstimatedbasedonemissionestimatesfromtheIPCCSpecialReportonglobalwarmingof1.5°CandUnitedNationspopulationprojections.Themediumfertilityvariantwasused(UNDESA,PopulationDivision2019).toreducetheirpercapitaemissionsbymorethanonethirdbetween2010and2030undercurrentpolicies.MexicoalsoperformswellintermsofitsprojecteddevelopmentofpercapitaemissionsunderbothcurrentpoliciesandNDCscenarios.PercapitaemissionsundercurrentunconditionalNDCtargetsareprojectedtoincreasebetween2010and2030forsevenG20members.Figure2.6.PercapitagreenhousegasemissionsoftheG20anditsindividualmembersby2030undernationallydeterminedcontributionsandotherannounced2030pledgesasat30September2021,currentpoliciesscenarioprojectionsfromindependentstudiesmainlypublishedaftertheCOVID-19outbreak,and2010historicallevels0302010525152010UnconditionalNDCCurrentpoliciesPercapitaemissions(tCO2e/capita)Levelsofpercapitaemissionsconsistentwith2°Cand1.5°Cscenariosby2050MexicoSaudiArabiaIndonesiaChinaArgentinaSouthAfricaAustraliaTurkeyUSABrazilCanadaJapanEU27IndiaUK1.6tCO2e/capita0.9tCO2e/capitaAnnouncedpledgeG20RussianFederationRepublicofKoreaNotes:i)FiguresincludeLULUCF.ii)Centralestimatesareamedianvaluewhenfiveormorestudieswereavailable,otherwisetheyareaveragevalues.iii)Dataonhistoricalandprojected(mediumfertilityvariant)populationpercountryaretakenfromthe2019RevisionofWorldPopulationProspects(UnitedNationsDepartmentofEconomicsandSocialAffairs[UNDESA],PopulationDivision2019).iv)Thefigurespresentedheremaynotexactlymatchofficialdataduetothedifferencesindatasources.v)G20membersaresortedindecreasingorderofNDCemissionsprojections.vi)ToestimateG20totalemissionsfortheNDCandannounced2030pledgesscenario,emissionsprojectionsunderthecurrentpoliciesscenariowereusedforIndia,theRussianFederationandTurkey.18EmissionsGapReport2021:TheHeatIsOnNet-zeroemissionstargetsLeadauthors:JoeriRogelj(ImperialCollegeLondon,UK;InternationalInstituteforAppliedSystemsAnalysis,Austria),StephenM.Smith(OxfordUniversity,UK),ShaYu(PacificNorthwestNationalLaboratory,USA)Contributingauthors:JiyongEom(KoreaAdvancedInstituteofScienceandTechnology[KAIST],RepublicofKorea),TarynFransen(WorldResourcesInstitute,USA),ClaireFyson(ClimateAnalytics,Germany),ThomasHale(OxfordUniversity,UK),FredericHans(NewClimateInstitute,Germany),JohnLang(Energy&ClimateIntelligenceUnit,UK),SilkeMooldijk(NewClimateInstitute,Germany),KatieRoss(WorldResourcesInstitute,USA)33.1IntroductionAchievingglobalnetzeroinlinewiththeParisAgreementrequiresrapidanddeepreductionsinglobalgreenhousegas(GHG)emissions,andthescaling-upofremovals.Emissionsreductionsareessentialtokeepthechallengeofhaltingglobalwarmingasmanageableaspossible.Removalsareusedtobalanceoutemissionsfromactivitiesforwhichwehavenotreducedemissionstozero–hencetheconceptof‘netzero’–aswellastodelivernet-negativeglobalemissionsthatcangraduallyreversethewarmingalreadycaused.Onepromisingdevelopmentistheannouncementoflong-termnet-zeroemissionspledgesbyanincreasingnumberofcountriesthatcurrentlyaccountformorethanhalfofglobalemissions.However,thesepledgeshavelargeambiguitiesandfewofthelatestnationallydeterminedcontributions(NDCs)putcountriesonaclearpathtowardstheirnet-zeropledges.Thereisanurgentneedtobacknet-zeropledgesupwithnear-termtargetsandactionsthatgiveconfidencethatnet-zeroemissionscanultimatelybeachieved.Thischapterlooksathownet-zeroemissionstargetshaveemergedfromthescientificunderstandingoftheclimatesystemandthegoalsoftheParisAgreement(section3.2).Itsetsouttheconsiderationswhentranslatingnetzerofromaglobalscientificconcepttonationalpolicytargets(section3.3),andassessescurrenttargetsintermsoftheirambition,scope,transparencyandconsistencywithnear-termplansandactions(sections3.4and3.5).3.2Thescienceofnet-zeroemissionstargetsNet-zeroemissionsisastatewherethesumofallanthropogenicemissionsandremovalsiszero.Net-zeroemissionstargetsarebeingdefinedinavarietyofways–themostimportantaspectfromaglobalgeophysicalperspectivebeingwhethertheycoverallGHGsorcarbondioxide(CO2)only(Rogeljetal.2015).Net-zeroGHGemissionsareachievedwhentotalaggregateGHGemissionsoveragivenperiodareequaltoanequivalentamountofaggregateGHGremoval(IntergovernmentalPanelonClimateChange[IPCC]2021b).Net-zeroCO2emissionsaredefinedsimilarlybutforCO2only.Othertermssuchas‘carbonneutrality’and‘climateneutrality’areoftenusedinterchangeablyfornet-zeroCO2andnet-zeroGHGemissions,respectively.However,astheirmeaningcandifferdependingoncontextandlanguage,furtherspecificationisneededtoavoidambiguity(seeglossaryforvariousdefinitionsofnet-zeroterms).3.2.1.Net-zeroCO2emissionsstabilizeglobalwarming,whereasnet-zeroGHGemissionsresultinapeakanddeclineinglobalwarmingAsaconcept,net-zeroemissionswereintroducedwelloveradecadeagoasawayofthinkingaboutminimizingsociety’simpactontheclimateandtheenvironment(UnitedNationsEnvironmentProgramme[UNEP]2008;Worth2005).Theconceptgainedtractionafterseveralscientificstudiesinthe2000sestablishedanear-linearrelationshipbetweenglobalwarmingandthetotalamountofnetanthropogenicCO2emissionseveremitted.Reachingnet-zeroCO2emissionsresultsinCO2concentrationsgraduallydecliningovertimetowardsalong-termequilibriumaspartoftheexcessCO2intheatmosphereisredistributedbytheuptakeinthebiosphereonlandandintheocean.Asaresult,CO2-inducedtemperaturestabilizes(Allenetal.2009;Collinsetal.2013;Joosetal.2013;KnuttiandRogelj2015;Leeetal.2021;MacDougalletal.2020;Matthewsetal.2009;MatthewsandCaldeira2008;Meinshausenetal.2009;Solomonetal.2010;Zickfeldetal.2009).19EmissionsGapReport2021:TheHeatIsOnTheseinsightswereconsolidatedintheFifthAssessmentReportoftheIntergovernmentalPanelonClimateChange(IPCC)wheretheywereusedtoestablishthegeophysicalrequirementsforhaltingglobalwarmingandtoestimatecarbonbudgetsconsistentwithpreventingwarmingfromexceedingspecifiedlevels(Collinsetal.2013;IPCC2014,2013;Stockeretal.2013)(seebox3.1).ThemostrecentIPCCassessmentreport(theSixthAssessmentReport,AR6)confirmsthatwarmingisexpectedtostabilizeonceglobalCO2emissionsreachnet-zerolevels(IPCC2021a;Leeetal.2021).Fornon-CO2emissions,theglobaltemperatureimpactofachievingnet-zeroemissionsdependsonhowlongtheGHGpersistsintheatmosphere(Pierrehumbert2014;Solomonetal.2010).Methane,currentlythesecond-largestcontributortowarming,hasamuchshorterlifetimethanCO2.Therefore,ifmethaneemissionsreducetozero,concentrationsfallfaster,andtheircontributiontoglobaltemperaturewilldecline.Achievingnet-zeroGHGemissionsexpressedwiththedefaultGWP-100metricthroughacombinationoflow1PartiestotheParisAgreementaremandatedtoreportaggregatedgreenhousegasemissionsbyusingtheGWP-100metric,whileadditionalinformationthatusesotheraggregationscanalsobeprovided.Notethatinaddition,emissionsofthevariousGHGsalsohavetobereportedindividually.residualnon-CO2emissionsandCO2removalresultsinapeakthenadeclineinglobalwarming(figure3.1)(Forsteretal.2021;Fuglestvedtetal.2018;IPCC2021b;Rogeljetal.2021).Themagnitudeofthisdeclinedependsontheminimumleveltowhichnon-CO2GHGscanbereduced,butcouldpotentiallybearound0.02–0.05°C/decade(Fuglestvedtetal.2018).Atpresent,noneoftheavailablemitigationscenariosfullyeliminateallCO2orotherGHGemissions(Clarkeetal.2014;Gernaatetal.2015;Rogeljetal.2018;Smithetal.2014).Toreachnet-zeroemissions,residualemissionsarethusbalancedbyremovalsfromtheatmosphere:hencetheinclusionof‘net’innet-zerotargets.ThemostscalableformsofGHGremovalareCO2removalmeasures(Fussetal.2018;Nemetetal.2018).Thismeansthatnet-zeroCO2emissionsareachievedbeforenet-zeroGHGemissions.Reachingnet-zeroGHGemissionstargetsthereforeinvolvesatleasttwo,andinmostcasesthree,interlinkedstrategies:deepreductionsinCO2emissions,theupscalingofCO2removal,anddeepreductionsinotherGHGemissions(figure3.1).Box3.1.CarbonbudgetsGlobalwarmingisclosetolinearlyproportionaltothetotalnetamountofCO2thathaseverbeenemittedintotheatmosphereasaresultofhumanactivities.Therefore,limitingglobalwarmingtoaspecifiedlevelrequiresthatthetotalamountofCO2emissionseveremittedbekeptwithinafinitecarbonbudget.Recently,AR6publishednewestimatesoftheremainingcarbonbudgetforlimitingwarmingto1.5°Cor2°Crelativetopre-industriallevels(Canadelletal.2021;IPCC2021b).Accordingtothese,humanactivitiesresultedinabout2,390GtCO2between1850and2019,contributingaroundthreequartersofthe1.07°Cofhuman-inducedwarmingfrom1850-1900to2010-2019.Tolimitwarmingto1.5°Cwitha66percentor50percentchance,theremainingcarbonbudgetisestimatedat400and500GtCO2,respectively.For2°C,theseestimatesare1,150and1,350GtCO2,respectively.CurrentannualglobalCO2emissionsareabove40GtCO2/year,meaningthaturgentanddeepemissionsreductionsoverthenextdecadearerequiredtostaywithintheremainingbudgets.AR6clarifiesthatmethodologicalimprovementscausetheestimatesinthelatestreporttobemarkedlylargerthaninAR5(Stockeretal.2013),butverysimilartothosereportedintheIPCCSpecialReportonglobalwarmingof1.5°C(Rogeljetal.2018)(seebox5.2inCanadelletal.(2021)formoreinformation).Carbonbudgetsarenottheonlydeterminantofglobalwarming.Thewarmingthataccompaniesnon-CO2emissionsalsoplaysarole.AR6carbonbudgetsassumethatnon-CO2emissionsarereducedfollowingthemedianreductionsfromdeepmitigationscenarios(Canadelletal.2021;Rogeljetal.2018).Formethane,thisimpliesatleasta30percentreductionin2030comparedwith2010,andabouta50percentreductionin2050.Remainingcarbonbudgetsmayvarybyanestimated220GtCO2ormore,dependingonhowdeeplyfuturenon-carbon-dioxideemissionsarereduced(Canadelletal.2021).Chapter6assessestheroleofmethaneinmeetingtheseemissionsreductionsandbridgingtheemissionsgap.TotalGHGemissionsareaggregatedinunitsofCO2equivalence.Althoughseveraldifferentmetricsfordefiningthisequivalenceexist(Myhreetal.2013),undertheParisAgreementGHGemissionsmustbeaggregatedusingtheglobalwarmingpotentialovera100-yeartime-horizon(GWP-100)metric1(UnitedNationsFrameworkConventiononClimateChange[UNFCCC]2018).20EmissionsGapReport2021:TheHeatIsOnFigure3.1.Illustrationofhownet-zerocarbondioxideornet-zerogreenhousegasemissionsarereachedatagloballevel(top)andthetypicalglobalwarmingimplicationsofreachingtheserespectivetargets(bottom)Figure3.1bGlobalwarmingimplicationsFigure3.1aGlobalgreenhousegas(GHG)emissionsandtimesofachievingnetzeroforanillustrativepathwaythatkeepswarmingwellbelow2°C201020202030204020502060207020802090210000.51.01.52.0Globalaveragetemperatureincrease(°Crelativeto1850–1900)2.5Net-zeroCO2emissionsGlobalwarmingroughlystabilizesNet-zeroGHGemissionsGlobalwarmingpeaksthendeclines2010202020302040205020602070208020902100–200204060GlobalCO2-equivalentemissions(GtCO2e/yr)NettotalGHGemissionsNet-zeroCO2emissionsachievedwhenresidualCO2emissionsarebalancedbyanequalamountofCO2removalNet-zeroGHGemissionsachievedwhenresidualCO2andotherGHGemissionsarebalancedbyanequivalentamountofCO2removalNetCO2emissionsContinueddeclineacceleratedfurtherifnet-negativeGHGemissionsareachievedGrossCO2emissionsNon-CO2emissions(CH4,N2OandflourinatedgasesinGWP-100)Net-negativeGHGemissionsGrossCO2removalNote:GWP-100standsforglobalwarmingpotentialovera100-yeartime-horizon,andisthemetricthatismandatedtobeusedundertheUnitedNationsFrameworkConventiononClimateChange(UNFCCC)toreportaggregatedanthropogenicemissionsandremovalsofGHGs.Reachingnet-zeroCO2emissionsresultsinglobalwarmingstabilizing,providedthatnon-CO2forcingisalsostabilized(Allenetal.2018;IPCC2018),whilereachingnet-zeroGHGemissionsdefinedwithGWP-100resultsinglobalwarmingpeakingandsubsequentlygraduallydeclining(Fuglestvedtetal.2018).FigureadaptedfromRogeljetal.(2021).PathwaytakenfromHuppmannetal.(2018a,2018b)andclimateoutcomeassessedusingtheModelfortheAssessmentofGreenhouseGasInducedClimateChange(MAGICC)(Meinshausenetal.2011).Notethatthisfigureshowsoneillustrativescenarioinwhichthenet-zerotimingsofCO2andtotalGHGemissionsarenotnecessarilyequaltothemedianestimatesoftheIPCCSpecialReportonglobalwarmingof1.5°C(IPCC2018).21EmissionsGapReport2021:TheHeatIsOn3.2.2.TheParisAgreementandthetimingofnet-zeroemissionsInthelead-uptotheParisAgreement,thesegeophysicalconceptsofcarbonbudgetsandnet-zeroemissionswereproposedaskeyelementsforalegalarchitecture(Haites,YaminandHöhne2013),andstudiesproposednet-zerodatesforglobalCO2andtotalGHGemissionsinlinewithspecifictemperaturelimits(Rogeljetal.2015).TheParisAgreementmarkedtheincorporationofthenet-zeroconceptintointernationalpolicy,aimingto“achieveabalancebetweenanthropogenicemissionsbysourcesandremovalsbysinksofgreenhousegasesinthesecondhalfofthiscentury,onthebasisofequity,andinthecontextofsustainabledevelopmentandeffortstoeradicatepoverty”(UNFCCC2015).Subsequently,theIPCCSpecialReportonglobalwarmingof1.5°Chighlightedthattolimitwarmingto1.5°Cabovepre-industriallevelswithnoorlimitedovershoot,globalCO2emissionsshouldreachnetzeroaroundmid-century(IPCC2018).Thelatterspurredawaveofnet-zerotargetdeclarations.Table3.1providesglobalnet-zerotimingsfrommodelpathwaysalignedwith1.5°Cand2°Climits.For1.5°C,CO2emissionsmustreachnetzeroaround2050,withGHGemissionsreachingnetzero15–20yearslater.Adelayof15–20yearsineithernet-zeroCO2ornet-zeroGHGsimplieslimitingwarmingto2°Cratherthan1.5°C.Table3.1.Globaltimingofnet-zerocarbondioxideandnet-zerogreenhousegasemissions.MedianandinterquartilerangePathwaycategoryNo.ofscenariosTimingofreachingnetzeroTimingofreachingnetzeroGlobalCO2emissionsGlobalGHGemissionsSR1.5:1.5°Cwithnoorlimitedovershoot(50–66%chancein2100withmaximumof0.1°Covershootuntilthen)422050(2046,2055)2067(2061,2084)SR1.5:Lower-2°C(66%chance)542070(2063,2079)Post-2100(2090,post-2100)1.5°Cpathways(66%chancein2100,andminimum33%chanceoverthecourseofthecentury,UNEPCh4)262054(2049,2059)2071(2058,post-2100)1.8°Cpathways(66%chance,UNEPCh4)232067(2057,2083)2086(2068,post-2100)2°Cpathways(66%chance,UNEPCh4)712069(2059,2089)2090(2077,post-2100)Note:SR1.5standsforIPCCSpecialReportonglobalwarmingof1.5°C.IPCCestimatesasreportedintable2.4ofSR1.5(Rogeljetal.2018).ValuesshowthemedianandinterquartilerangeacrossscenariosavailableintheSR1.5scenariodatabase(Huppmannetal.2018a).Inthepathwaycategoriesasusedinchapter4ofthisreport,pathwayswithemissionsreductionsbefore2020areexcluded.ThetemperatureoutcomesofthesepathwayshavealsobeenreassessedbasedonthephysicalclimateassessmentoftheIPCCAR6–seecross-chapterbox7.1inForsteretal.(2021).3.2.3.Thepathwaytonet-zerocountsCarbonbudgetscomewithclimateimplicationsfornet-zerotargets:thepathfollowedfromtodayuntilnet-zeroCO2emissionsarereacheddeterminesthetotalamountofemittedCO2andtherebythetotalcarbonbudget.Whetherwefollowalinear,anaccelerated,oradelayedpathimpactstheclimateoutcome(figure3.2).Followingadelayedpathcomparedtoanacceleratedpathtonet-zeroGHGemissionsby2065couldleadtoabout0.1°Cmorewarming.Atworst,adelaycouldresultinacompletefailuretoachievethenet-zerotarget,resultinginhigherwarming.Near-termemissionsreductionsthatsketchalinearoracceleratedpathtowardsalonger-termnet-zerotargetthereforeprovidehigherconfidencethatthenet-zerotargetcanultimatelybeachieved.22EmissionsGapReport2021:TheHeatIsOnFigure3.2.Near-termtargetsarecriticaltosetglobalemissionsonaclearpathtowardsachievinglong-termnet-zerotargetsandstringentclimategoals02040Globaltotalgreenhousegasemissions[GtCO2e/yr]60onadelayedpath=near-termtargetssettingemissions...Additionalcumulativeemissionsleadingtohigherwarming,highermitigationchallenges,andgreaterdifficultyinachievingthenet-zerotargetonalinearpath,oronanacceleratedpath...towardsachievingthelong-termnet-zerotarget2020204020602080210020102030205020702090Accelerated:theNDCreducesemissionsfurtherthanimpliedbyalinearpathtowardsthenet-zerotarget.Cumulativeemissionsarefurtherreducedcomparedtoalinearpath.Linear:theNDCsetsemissionsapproximatelyonalinearpathtowardsachievingthenet-zerotarget.Delayed:theNDCreducesemissionsmoreslowlythanimpliedbyalinearpathtowardsthenet-zerotarget.Cumulativeemissionsandresultingglobalwarmingarehighercomparedtoalinearpath.Globalnet-zeroemissionstargetsinisolationsetonlyaweaklimitonthemaximumlevelofglobalwarming(Rogeljetal.2015),asthemaximumlevelofwarmingislargelydefinedbythecumulativeamountofCO2emissionsemitteduntilnetzero(IPCC2018).3.3.Net-zeroatthenationallevelSettingnet-zeroemissionstargetsatthenationallevelinvolvesseveralstepsinadditiontotheaforementionedglobalconsiderations.Thesestepsrepresentbothtechnicalchoicesandnormativedecisionsrelatedtoequityandfairness.Althoughthischapterfocusesoncountries,therearesimilarstepstotranslateglobalnet-zerotargetstosectors,companies,investmentportfoliosandotherentities(seebox3.2).First,atatechnicallevel,thescopeofemissionscoveredbyanet-zerotargetneedsdefining(Levinetal.2020;Rogeljetal.2021).ThisincludesdefiningtheGHGsandactivitysectorsthatarecovered.Forcountries,theUNFCCC'srequirementthatpartiesreportemissionsandremovalsofabasketofGHGsonaterritorialbasisinformsthescopeofnationaltargets.Countriescouldhoweverexcludesomegasesoractivities,includeotherssuchasinternationalaviationandshipping,ortakeadifferentapproachsuchasconsumption-basedaccounting(DavisandCaldeira2010;MunksgaardandPedersen2001;WyckoffandRoop1994).Afurtherchoiceinscopeistheinclusionanduseofcarbonoffsets,whicharecreditsgeneratedbyprojectscarryingoutemissionsreductionorremovaloutsideacountry’s(orotherentity's)boundary.Thesecreditsaretransferredtobeaccountedforwithintheboundary,often–butnotalways–byfinancialpurchasethroughamarket.Marketscanallowentitiestomeettargetsinamoreeconomicallyefficientway(Grubbetal.2011).However,experienceshowsthatinternationalcarbonmarketscanhavepitfalls.Largenumbersofcredit-generatingprojectsintheCleanDevelopmentMechanism–themarketoperatedundertheKyotoProtocol–werefoundnottofullyrepresentadditionalcarbonbenefits23EmissionsGapReport2021:TheHeatIsOn(Camesetal.2016).TheParisAgreementanticipatesanewinternationalregimeforcarbonmarketsunderarticle6,theoperationofwhichisstillundernegotiation.Thiswillrequireclearlydefinedrulesandrobustaccountingmechanismstotrackprogress,deliverrealemissionsreductionsanddriveambition.Chapter7furtherdiscusseschallengesandopportunitiesinusingmarketsinachievingParisAgreementtargetsinboththenear-termandnet-zerocontext.Second,normativechoicesarerequiredwhentranslatingglobalnet-zerotargetstothecountrylevel,involvingquestionsofequityandfairness.Adeadlineforglobalnet-zeroemissionsdoesnotrequireallcountriestoachievenetzeroatthesametime(RobiouduPontetal.2016;Rogeljetal.2021).Factorssuchasresponsibility,capacityandlevelofdevelopmentimplythatsomenationsshouldachieve(andgobeyond)net-zeroemissionsmorequicklythanothers(Dubashetal.2021;Rogeljetal.2021).Furthermore,thecostsofandpotentialforachievingemissionsreductionsandremovalsaregeographicallyunevenlydistributed.Reachingglobalnet-zeroemissionsisthereforelikelytoinvolveacombinationofpositiveandnegativeemissionscontributionsacrosscountriesandsectors,keepinginmindthattheglobalpotentialfornegativeCO2emissionsislimitedbecauseoftechnical,socialandsustainabilityreasons(IPCC2019,2018).Thisvariationbetweencountriesisillustratedbythedifferenttimesatwhichregions(Rogelj2018)ormajoremittingcountries(vanSoestetal.2021)reachnet-zeroCO2orGHGemissionsaspartofagloballeast-costtransition,irrespectiveofadditionalequityorfairnessconsiderations.2Seehttps://unfccc.int/process/the-paris-agreement/long-term-strategies.Asidefromquestionsofequityandscope,debateshaveemergedoverwhethernet-zerotargetspromoteorhinderactionsconsistentwiththeParisAgreement.Net-zeroisseenasmoreactor-centredandeffectivethanatemperaturelimit(Geden2016).Italsorepresentsgreaterambitionthanthecurrentlong-termpledgesofmostcountries.2Nevertheless,theconceptofnet-zerohasfacedcriticismonthegroundsthatitmayslowmitigation,eitherthroughover-relianceoncarbonremoval(McLarenetal.2019)oroncarboncredits(Stabinsky,BhatnagarandShaw2021),orbecauseanemphasisonlong-termtargetscandistractfromalackofnear-termactions.Othercriticshighlightthatanarrowfocusonnet-zerotargetscanlosesightofdifferencesinnationalclimatepolitics,orthecredibilityofpledges,aswellasequity(Dubashetal.2021;Rogeljetal.2021).Net-zerotargetsarenottobeviewedinisolationasthesolepolicymechanismforeffectingchange;theyshouldbeaccompaniedbynear-termactionsaswellasdetailedandtransparentplansfordelivery(Rogeljetal.2021;Smith2021).TheParisAgreementencouragesthesethroughthesubmissionofNDCsandlong-termstrategiestotheUNFCCC.Inresponsetotheseissuesandcriticisms,severalrecentstudieshavefocusedonidentifyingasetofcriteriaagainstwhichtherobustnessofnet-zeropledgescanbeassessed(Blacketal.2021;ClimateActionTracker2021;Levinetal.2020;Rogeljetal.2021).Theyshareseveralcommonfeatures,summarizedintable3.2.24EmissionsGapReport2021:TheHeatIsOnTable3.2.Overviewofcriteriausedtoassessnationalnet-zeropledgesStudiesClimateActionTracker(2021)Energy&ClimateIntelligenceUnit–Oxford(Blacketal.2021)Rogeljetal.(2021)WorldResourcesInstitute(Levinetal.2020)GoalTargetyearWhenwillnetzerobeachieved?xxxxLegalstatusIsthetargetbindingindomesticlaw,orwhatotherformofcommitmentisit?xxxGlobalclimategoalWhatglobaltemperaturelevelisthetargetdesignedtocontributeto?xInterimtargets/actionWhatisthepathtonetzero?xxxPathwayafternetzeroIstheintenttomaintainnetzero,ortoreachnetnegative?xReferencetofairnessHasthetargetbeenjustifiedasafairandadequatecontributiontotheglobalgoal?Ifso,how?xxxxScopeGascoverageDoesthetargetincludeallGHGsundertheParisAgreement,orasubset?xxxxSectorcoverageDoesthetargetincludealldomesticactivities,orasubset?xCoverageofinternationalaviationandshippingDoesthetargetincludeashareofinternationalaviationand/orshipping?xxxUseofinternationaloffsetsDoesthetargetallowsuchoffsetstobecountedtowardsthetarget?xxxxTransparencyPublishedplanHasthegovernmentsetoutaplanofactionstoachievethetarget?xxxReviewprocessIstherearegular,bindingprocessforreviewingandrevisingthetarget?xReportingofprogressIsthereregularreportingofprogressagainstthetarget?xSeparatereductionsandremovalsDoesthetargetincludeseparatesubtargetsforemissionsandremovals?xxxTransparencyonremovalsAreassumptionsaboutuseofremovalmethods,bothinthelandandindustrysectors,transparent?xxMetricforaggregatingemissionsIfthetargetisformultipleGHGs,doesitusetheGWP-100metricundertheParisAgreement?Ifnot,whynot?xNote:“x”indicateswhichcriteriaareincludedineachofthefourpublishedstudies.3.4.Trackingnationalnet-zerotargetsgloballyThenumberofnationalnet-zerotargetshasgrownrapidlyoverthelastfouryears.Bythebroadestdefinition,asmanyas136countriescoveringmorethanhalfofglobalGHGemissionseitherhavesomeformofcommitmenttosuchatargetorareconsideringit(ClimateActionTracker2021;Energy&ClimateIntelligenceUnit[ECIU]2021;UNEP2020;WorldResourcesInstitute2020).Thisincludescountrieswhosegovernmentsaremerelydiscussingnet-zerotargets,andsignatoriestotheClimateAmbitionAlliancewhichcitesworkingtowardsnet-zeroCO2emissionsby2050amongitsaims(ClimateAmbitionAlliance2019).25EmissionsGapReport2021:TheHeatIsOnHerewedefineanet-zerotargetasastatementinnationallegislation,inapolicydocument(i.e.anNDCorlong-termstrategycommunicatedtotheUNFCCC,orasimilardocumentpublishedbyanationalgovernment),orapublicannouncementbythegovernmentorahigh-levelgovernmentofficial(e.g.HeadofState).Weincludereferencestonet-zeroemissions,net-zerocarbon,carbonneutral(ity),GHGneutral(ity),climateneutral(ity)andadecarbonizedeconomyorsociety.Ouranalysisreflectsdevelopmentsupto13September2021.Usingthisclassification,50parties(49countriesplustheEuropeanUnion)havepledgedanet-zerotarget.Thesecoveraround57percentofcurrentglobaldomesticGHGemissions,60percentofgrossdomesticproduct(GDP)and34percentoftheglobalpopulation(ClimateWatch2021;WorldResourcesInstitute2021).Eleventargetsareenshrinedinlaw,covering12percentofglobalemissions(table3.3).Table3.3.Overviewofcurrentnationalnet-zeropledgesacrossallUnitedNationsFrameworkConventiononClimateChange(UNFCCC)parties,byyearandbylegalstatusPartiesEmissionsGDPPopulationInlaw1112%10%3%Inpolicydocument2415%24%7%Governmentannouncement1530%26%24%Sources:Totalcoverageofcurrentnet-zeropledgesbypercentageofglobaldomesticemissionsin2018(WorldResourcesInstitute2021),GDP(WorldBank2019,inpurchasingpowerparity(PPP)constantinternational$terms)andpopulation(UNWorldPopulationProspects2019)Bynumber,themajorityofthesetargets(38)arefor2050,coincidentwiththemid-centurytimescaleforglobalCO2emissionsindicatedbytheIPCCasnecessaryforlimitingwarmingto1.5°C.Eighttargetsareaimedatearlieryears(2030–2045)andfouratlateryears.Intermsofemissions,however,thetargetsaresplitalmostentirelyandequallybetween2050(duetothepledgesbytheEuropeanUnionandUnitedStatesofAmerica)and2060(duetoChina’spledge).Itisimportanttonotethatapproachestocountingcarbonsourcesandsinkscandifferbetweenglobalstudiesandnationalreporting.Somecareisthereforeneededwhenassigningnet-zerostatustocountries,orinterpretingclaimsbycountriesthat‘carbonneutrality’hasbeenachieved.Inparticular,nationalGHGinventorieslabelallcarbonuptakeonmanagedland(includingnaturallyoccurringuptake)asanthropogenic,resultingingreaterremovalnumbersthaninthescientificmodellingstudiesthatformthebasisfortheglobalemissionspathwaysassessedinchapter4ofthisreport(Grassietal.2021,2018).However,oneavailablestudyindicatesthatdifferencesbetweenthetwoapproachesatthegloballevelleadtoanegligibledifferenceintermsoftimingofnet-zeroemissions(Grassietal.2021).Furtherin-depthstudiesarerequiredtoconfirmthis.Existingnet-zerotargetsshowvariationsinscope,aswellaslargeambiguities(WorldResourcesInstitute2020).Thirty-fourareclearinincludingallsectorsofdomesticactivity,whiletheremaining16areunclearorundecided.RegardinginclusionofGHGs,17targetsareunclearorundecided,howeverthosethatareclearallincludeatleastsomenon-CO2gasesaswellasCO2.Themajority(39)areunclearorundecidedoninclusionofemissionsfrominternationalaviationandshipping.However,threeexplicitlyincludethem.Similarly,onuseofoffsets,fiveincludethemexplicitly,eightrulethemoutand37areunclearorundecided.Asalreadyexplained,achievingnet-zeroemissionsiskeytohaltingorevengraduallyreversingglobalwarming.Withanincreasingshareofglobalemissionscoveredbynet-zerotargets,theirimpactontemperatureprojectionsisalsoincreasinglyimportant.Chapter4–whichprovidesanoverviewofglobalwarmingimplicationsofcurrentpolicies,NDCsandnet-zerotargets–estimatesthatiffullyachieved,net-zerotargetscouldreduceglobalwarmingprojectionsbyabout0.5°CrelativetoprojectionsthatonlytakeintoaccountunconditionalNDCs.3.5.Acloserlookatnet-zerotargetsintheG20TwelveoftheG20members,covering54percentofglobaldomesticGHGemissions,currentlyhavepledgedanet-zerotarget,ofwhichsixareinlaw,twoareinpolicydocumentsandfouraregovernmentannouncements.Allarefortheyear2050,withtheexceptionofChina’s2060targetandGermany’stargetfor2045.26EmissionsGapReport2021:TheHeatIsOnFigure3.3providesanassessmentofthesetargetsagainstmostofthecriteriaprovidedintable3.3.Whereinformationrelevanttothecriteriaisavailablefromcountries,figure3.3highlightsitsexistenceratherthanassessingitssufficiency.Forinstance,aplanmaybepublishedanditmayrefertothefairnessofitscontributiontoglobalefforts,howeveradditionalassessmentisrequiredtoestablishwhethertheplanisdetailedenoughandthefairnessappropriate.Similartotheglobalassessmentofnationalnet-zerotargets,anotablefeatureofcurrentnet-zerotargetsofG20membersistheirambiguity.Regardingscope,mosttargetsareunclearorundecidedoninclusionofoffsetsandofinternationalaviationandshippingemissions.Lackofclarityisalsonotableoncoverageofsectorsandgases,butthosethatareclearshowatendencyforcomprehensivecoverage.Mostshowalackoftransparencyregardingtheapproachtakentofairness,theplansforachievement(includingonuseofremovals),andonreportingandreviewingprogress.OnlyCanada,theEuropeanUnion,France,GermanyandtheRepublicofKoreahavepublishedtheirplanssofar,andonlythesecountriesplustheUnitedKingdomhaveaccountableprocessesforreviewingtheirtargets.Asanindicationoftheconsistencybetweennearer-termactionsandnet-zerotargets,figure3.3alsoplotstheemissionspathsforG20membersimpliedbytheirmostrecentNDCsorannouncedmitigationpledgefor2030andtheirnet-zerotarget.Ashighlightedinsection3.2andfigure3.2,near-termtargetsneedtobealignedonaclearpathtowardsachievingnet-zerotargetsandlimitingcumulativeemissions.Indeed,theEmissionsGapReport2020(UNEP2020)arguedthatthelitmustestofnet-zeropledgesistheextenttowhichtheyarereflectedinnear-termpolicyactionandinsignificantlymoreambitiousNDCsfortheperiodto2030.Near-termemissionsreductionsthatfollowalinearoracceleratedpathtowardsanet-zerotargetprovidehigherconfidencethatthenet-zerotargetcanbeachieved.Tosummarize,eightG20membershavesofarnotsetnet-zerotargets,whereas12(covering54percentofglobaldomesticGHGemissions)have.OfthenineG20membersforwhichwecanestimateanemissionspathbasedontheirnet-zerotargetandtheirNDC,nonehaveNDCtargetsthatputthemonanacceleratedpathtowardstheirnet-zeroemissionstargets.Fiveoftheseninemembers(covering21percentofglobaldomesticGHGemissions)haveNDCtargetsthatputthecountry’sdomesticemissionsontoalinearpathtowardsachievingtheirnet-zerotargets.ForfourG20members(covering28percentofglobaldomesticGHGemissions),theNDCsleadtoemissionsin2030thatareabout25percentto95percenthigherthanalinearpathtowardstheirnet-zerotargetswouldimply.Thesecountriesurgentlyneedstrengthenedandmoreambitiousnear-termclimateplansfortheirnet-zerotargetstoremainachievable.Thereisanurgentneedfor(i)moreG20members–andindeedallcountries–topledgenet-zeroemissions,(ii)allcountriestoincreasetherobustnessoftheirnet-zeropledges,and(iii)allnet-zerotargetstobebackedupbynear-termactionsthatgiveconfidencethatthenet-zerotargetscanultimatelybeachieved.27EmissionsGapReport2021:TheHeatIsOnFigure3.3.Analysisofcurrentnet-zerotargetsofG20membersCountryPathtonetzeroYearTargetstatusReferstofairnessAllgasesAllsectorsInt.aviation&shippingExcludesoffsetsPub-lishedplanReviewprocessReportingprogressSeparatetargetsRemovalstransparencyArgentina2050Governmentannouncement????Brazil2050Governmentannouncement???Canada2050Inlaw??NotannuallyChina2060Governmentannouncement???EuropeanUnion2050Inlaw?NotannuallyFrance2050InlawAnnuallyGermany2045InlawAnnuallyItaly2050Governmentannouncement????Japan2050Inlaw??NotannuallyRepublicofKorea2050Inpolicydocument????NotannuallyUK2050InlawAnnuallyUSA2050Inpolicydocument??Key:202020402060SchematicillustrationofwhetherNDCsareputtingnationalGHGemissionsonadelayed,linearoracceleratedpathtowardsachievingthenationalnet-zerotarget(seebox3.1)YesNoUnclearorundecidedNotannually(reportingprogressbutlessfrequentlythanannually)205020502050206020502050205020502050Note:OnlyG20memberswithnetzerotargetsareincluded.MemberstatesoftheEuropeanUnionhavenoseparateassessmentoftheirpathtonetzero,becausetheirNDCisnotassessedseparatelyaspartofthisreport.Table3.2providesdefinitionsofwhatiscoveredunderthevariousheaders.28EmissionsGapReport2021:TheHeatIsOnBox3.2.Non-stateactiononnetzeroBusinesses,cities,regions,investors,civilsocietygroups,andothernon-stateandsubnationalactors(NSAs)playanincreasinglyimportantroleinraisingambitionandacceleratingimplementation.TheParisAgreementinstitutionalizedtheengagementofNSAsinachievinglong-termclimategoalsandcreatedanongoingprocesstocatalyseclimatecommitmentsmadebyNSAs,includingnet-zerotargets(Chan,EllingerandWiderberg2018;Hale2016;Hsuetal.2018).EffortsbyNSAstowardsglobalnet-zeroemissionsarestrengtheningandbroadening,whichhelpsmobilizestakeholderstoachievenetzero(Data-DrivenEnviroLabandNewClimateInstitute2020;Hsuetal.2020).TheUnitedNationsRaceToZerocampaignralliesNSAsgloballytotakerigorousactionstoreduceemissionsby50percentby2030andachievenet-zerocarbonemissionsby2050atthelatest,vettingmembersviaanindependentexpertgroup.Morethan3,000businesses,730cities,170investors,30regionsand600universitieshavejoinedRaceToZero,togethercoveringaround25percentofglobalCO2emissionsand50percentofGDP(Blacketal.2021;NewClimateInstituteandData-DrivenEnviroLab2020;SmitandKuramochi2020;UNFCCC2021).ActionstakenbyNSAscanalsocontributetoachievingnet-zerotargetssetbygovernments,whileatthesametimecreatingmorefavourableconditionsforgovernmentstoincreasetheirambitiongoingforward.Arecentstudyofmajornon-stateactorinitiativesfoundtheyhadthepotentialtoreduce2030emissionsby5–15GtCO2e(Blacketal.2021;Haleetal.2021;Hsuetal.2019;NewClimateInstituteandData-DrivenEnviroLab2020;NewClimateInstituteetal.2021).Atthenationallevel,NSAsaresupportingimplementationandenhancementofclimategoals.Forinstance,AmericaIsAllIn(AAI),acoalitionofover1,800institutionsrepresenting65percentoftheUnitedStatesofAmerica’spopulationand70percentofitsGDP,isaninitiativetoenhancenon-stateactionstocuttheUnitedStatesofAmerica’sGHGemissionsby50percentbelow2005levelsby2030andputthecountryonatrajectoryconsistentwithlimitingglobaltemperatureriseto1.5°C(Hultmanetal.2021).Meanwhile,theEuropeanCommissionlaunchedtheEuropeanClimatePacttomobilizeNSAsandcommunitiestoparticipateinclimateactions.TheJapanClimateInitiative,madeupofbusinessesandmunicipalities,hasplayedakeyroleinsupportingthegovernment’snewNDC.However,theincreaseinNSAnet-zeropledgesneedstobetreatedwithcaution,becauseastheyhaveproliferated,theyhavevariedinrobustness.Thescopeandcoverageofnet-zerotargets;theexistenceofimplementationplans,transparencyandreportingtotrackprogress;thealignmentbetweennear-termactionsandlong-termnet-zerotargets;andtherobustnessofcarbonoffsetsarecriticaltocrediblenet-zerotargets(Blacketal.2021;Haleetal.2021;Hsuetal.2019;NewClimateInstituteandData-DrivenEnviroLab2020;NewClimateInstituteetal.2021).NSAshavestartedtotakeactionstoaddresstheseissues.Forexample,theTaskforceonScalingVoluntaryCarbonMarkets,aprivate-sector-ledinitiative,aimstodevelopathresholdstandardtoensurehighintegrityoffsetcreditsandcreaterobustandtransparentmarkets.29EmissionsGapReport2021:TheHeatIsOnTheemissionsgapLeadauthors:MicheldenElzen(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),JoanaPortugal-Pereira(GraduateSchoolofEngineering(COPPE),UniversidadeFederaldoRiodeJaneiro,Brazil),JoeriRogelj(GranthamInstitute,ImperialCollegeLondon,UK;InternationalInstituteforAppliedSystemsAnalysis[IIASA],Austria)Contributingauthors:IoannisDafnomilis(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands),JohannesGütschow(PotsdamInstituteforClimateImpactResearch,Germany),KimonKeramidas(JointResearchCentre[JRC],Spain),RobinLamboll(ImperialCollegeLondon,UK),JaredLewis(UniversityofMelbourne,Australia),MalteMeinshausen(UniversityofMelbourne,Australia),ZebedeeNicholls(UniversityofMelbourne,Australia)44.1IntroductionTheemissionsgapisestimatedasthedifferencebetweenprojectedglobalgreenhousegas(GHG)emissionsassumingfullimplementationofthemitigationpledgesthatcountrieshavemadefor2030,andemissionsunderleast-costpathwaysconsistentwiththeParisAgreement’slong-termgoaloflimitingglobalaveragetemperatureincreaseto“well-below2°C”andpursingeffortstolimititto1.5°C,comparedwithpre-industriallevels.Thisyear,theupdateoftheemissionsgapisparticularlyinterestingasitisthefirsttimecountrieshavesubmittedneworupdatednationallydeterminedcontributions(NDCs)aspartoftheParisAgreement’sfive-yearambition-raisingcycle.Thus,theupdateoftheemissionsgapprovidesanindicationoftheextenttowhichtheNDCprocessundertheParisAgreementisworkingandtheprogressmade.Toestimatetheemissionsgap,updatedscenariosthatunderlieitsquantificationareassessed(section4.2).Thisyear,themitigationpledgescenariosincludethelatestavailableNDCsaswellasannouncedmitigationpledgesfor2030withacut-offdateof30August2021.Further,scenariosconsidertherepercussionsoftheCOVID-19pandemicandpossibleeconomicrecoverypaths.Theemissionsgapassessmentfor2030ispresentedinsection4.3,whiletheimplicationsoffailingtobridgetheemissionsgapforglobaltemperaturerisearediscussedinsection4.4.Inthiscontext,thekeyquestionsassessedinthischapterare:Whatisourcurrentbestestimateoftheemissionsgapfor2030takingintoaccounttheneworupdatedNDCs,announcedpledgesandtheimpactoftheCOVID-19pandemicandassociatedrecoverymeasures?Whataretheglobalwarmingimplicationsoverthecourseofthecentury?4.2Scenariosconsideredforthe2030gapassessmentThissectionupdatestheeightscenariosconsideredforthe2030emissionsgapassessment.Thesescenarioscomprisereferencescenarios(4.2.1),NDCscenarios(4.2.2),andleast-costmitigationscenariosstartingin2020consistentwithspecifictemperaturetargets(4.2.3).Table4.1listsanddescribesallscenariosincludedintheassessment30EmissionsGapReport2021:TheHeatIsOnTable4.1.SummaryofassessedscenariosScenarioCut-offyearDescriptionReferenceYear2010policies2010Thisscenarioincludesonlyclimatepolicesimplementedupto2010(noadditionalmeasuresfrom2010onward).Currentpolicies2020/21Currentpoliciesupdatedtoreflectclimatemitigationpoliciesadoptedandimplementedasof2020/21.Scenarioalsoadjustedtoreflectshort-andmidtermsocioeconomicimpactsfromCOVID-19.1NDCsandannouncedmitigationpledgesUnconditionalNDCsandannouncedmitigationpledges2021ThisscenarioreflectsneworupdatedNDCsaswellasofficiallyannouncedmitigationpledgesfor2030thathavebeenindicatedtobeimplementedwithoutanyexplicitexternalsupport.(Cut-offdate:30August2021)ConditionalNDCandannouncedmitigationpledges2021Inadditiontotheunconditionalpledges,thisscenarioconsidersneworupdatedNDCsaswellasofficiallyannouncedmitigationpledgesfor2030tobeimplementedconditionaluponreceivinginternationalsupport(finance,technologytransferand/orcapacity-building).(Cut-offdate:30August2021)MitigationscenariosconsistentwiththeParisAgreementBelow2°CStartingfrom2020Long-termleast-costpathwayconsistentwithholdingglobalwarmingbelow2°Cthroughoutthetwenty-firstcenturywithatleast66percentchance.Below1.8°CStartingfrom2020Long-termleast-costpathwayconsistentwithholdingglobalwarmingbelow1.8°Cthroughoutthetwenty-firstcenturywithatleast66percentchance.Below1.5°CStartingfrom2020Long-termleast-costpathwayconsistentwithholdingglobalwarmingbelow1.5°Cthroughoutthetwenty-firstcenturywithlimitedornoovershooting.Globalwarmingin2100isprojectedtobebelow1.5°Cwithatleast66percentchance,whilethroughoutthetwenty-firstcenturyitiskeptbelow1.5°Cwithatleast33percentchance.1Theupdatedcurrentpolicyscenarioadjustsoriginalmodellingstudiestoaccountfordifferentpolicycut-offdates,whichrangefrom2017to2020,andvaryingconsiderationoftheimpactoftheCOVID-19pandemiconsocioeconomicdrivers.31EmissionsGapReport2021:TheHeatIsOn4.2.1ReferencescenariosandupdatesTworeferencescenariosareconsidered:the‘year2010policies’scenarioandthe‘updatedcurrentpolicies’scenario.Onlythelatterhaschangedcomparedtolastyear.Theyear2010policiesscenarioassumesthatnoadditionalclimatemitigationpoliciesareimplementedafter2010.Asinpreviousgapreports,globalGHGemissionsinthisscenarioarebasedonthebaselineprojectionsofSharedSocioeconomicPathwayscenariosfromsixmodellingstudiesassumingmiddle-of-the-roadsocioeconomicassumptions(SSP2)(Frickoetal.2017)thatalsounderpinthecurrentpoliciesscenarioprojectionsasof2019(McCollumetal.2018;Roelfsemaetal.2020).2TheupdatedcurrentpoliciesscenarioprojectsglobalGHGemissionsassumingallcurrentlyadoptedandimplementedpolicies(definedaslegislativedecisions,executiveorders,orequivalent)arerealizedandthatnoadditionalmeasuresareundertaken.ItalsoconsiderstheimpactofCOVID-19.Thedataforthisscenarioarebasedonupdatesbyfourmodellingstudies3thatincludetheimpactsofCOVID-19andhaveacut-offdateofNovember2020andfourinternationalmodellinggroups.4Theinternationalmodellinggroupshave31December2016astheircut-offdateforcurrentpolicies(Roelfsemaetal.2020)anddonotincludeCOVID-19effects.TheyareincludedtoensureconsistencyofthedatasetandmethodologyacrosstheEmissionsGapReports.TheirresultswereadjustedtoreflectupdatesofpoliciesuntilNovember2020bycomparingthemtotheresultsofthefourmodellingstudiesthatprovideestimatesforbothcut-offdates(denElzen,HöhneandJiang2017).Followingthisapproach,themedianestimateoftheimpactofrecentpoliciesisareductioninglobalGHGemissionsof1.5gigatonsofcarbondioxideequivalent(GtCO2e)(range:3.0–0.4).TocapturetheimpactofCOVID-19,thefourinternationalmodellinggroups'estimateswereadjustedbasedonthreeofthefourmodellingstudies(ClimateActionTracker,InternationalEnergyAgency[IEA]andPBL)thatprovideglobalGHGemissionsprojectionsbasedonconsistentcurrentpoliciesscenarios,includingaswellasexcludingtheimpactoftheCOVID-19pandemic.Followingthisapproach,theimpactofCOVID-19isanestimatedreductioninglobalGHGemissionsofabout2.5GtCO2e(range:3.2–1.4)by2030.Consideringbothoftheseimpacts,themedianestimateofglobalGHGemissionsin2FromtheCD-LINKSScenarioDatabase,version1.0.3ClimateActionTracker(2021);JointResearchCentre'sPOLESmodel(JointResearchCentre,forthcoming);PBLNetherlandsEnvironmentalAssessmentAgency'sIMAGEmodel(Dafnomilisetal.2021;denElzenetal.inreview;Nascimentoetal.2021)(seealso:www.pbl.nl/ndc);andthestatedpoliciesscenariooftheInternationalEnergyAgency[IEA]’sWorldEnergyOutlook2020(IEA2020).Themore-optimisticstatedpoliciesscenariooftheIEAWorldEnergyOutlook2020thatwasusedasacurrentpoliciesscenarioisnotyetincluded.Furthermore,theenergy-relatedCO2emissionsofIEAweresupplementedwiththemedianestimatesofthenon-CO2GHGemissionsandCO2land-use-relatedemissionsofthecurrentpoliciesscenariosfromtheCOMMITdatabase.4InternationalInstituteforAppliedSystemsAnalysis(IIASA)withtheMESSAGE–GLOBIOMmodel(Frickoetal.2017);NationalInstituteforEnvironmentalStudies(NIES)withtheAIMmodel(Fujimorietal.2017);PotsdamInstituteforClimateImpactResearch(PIK)withtheREMIND–MAgPIEmodel(Ludereretal.2015)andCOPPE,UniversidadeFederaldoRiodeJaneiro(COPPE/UFRJ)withtheCOFFEEmodel(Rochedoetal.2018).2030fortheupdatedcurrentpoliciesscenariobecomes55GtCO2e(rangeof52–58GtCO2e;seetable4.2)in2030,whichis4GtCO2elowerthanthemedianestimateofthe2020UNEPEmissionsGapReport.ItremainscriticallyimportanttounderstandthepotentialstructuralchangesoftheCOVID-19pandemicandthepost-COVIDrescueandrecoverypackagesonemissionlevelsoutto2030(seechapter5).Thisisparticularlyimportantgiventheuseof2030asatargetyearinmanycountries’NDCsubmissionsandasabenchmarktogaugeglobalclimateaction.Researchisongoinginthisarea,butnotyetpublishedinthepeer-reviewedliterature.Whileunderstandingofenergy-relatedGHGemissionstrendsduringtheCOVID-19pandemicisimproving(Forsteretal.2020;LeQuéréetal.2021,2020;Liuetal.2020),thereismoreuncertaintyaroundtrendsinagriculture,forestryandotherland-use(AFOLU)-basedGHGemissions.However,theseemissionsseemtocontinuetoincrease.In2020,agriculturalactivitieshadlimitedlossesduetotheCOVID-19pandemicandsomecommoditiesevenincreasedtheirproduction(FoodandAgricultureOrganizationoftheUnitedNations[FAO]2021a,2021b;WorldBank2021).Furtherglobaldeforestationratesincreasedsignificantly,resultinginalossoftreecoverby25.2Mha,12percentmorethanin2019(Hansenetal.2013;WorldResourcesInstitute[WRI]2021).Althoughnear-termimpactsonland-usedynamicsareyettobebetterknown,asinthe2000sand2010s,productionofagriculturalcommodities(mainlybeef,soy,andpalmoil),illegallogging,miningextractionandwildfiresweremajordriversofdeforestation(Curtisetal.2018;FAO2021c).Therisingtrendofpricesformostfoodandmetalcommodities(FAO2021a,2021b;WorldBank2021),alongwithgovernmentalstimulusintoagribusinessactivities,extractiveindustries,anddevelopmentofroadinfrastructureinprotectedlandregionsdrovedeforestationandforestdegradation,mainlyinthetropics(Brancalionetal.2020;FerranteandFearnside2020).DuringtheCOVID-19crisisandduetolimitedfinancingresources,somegovernmentshavealsorelaxedenvironmentallawsanddecreasedtheirnationalbudgetsofregulatorymechanisms,whichhasreducedtheenforcementofenvironmentalprotectionlaws(Amador-Jiménezetal.2020;Valeetal.2021).Furthermore,nationallockdownsanddisruptionofnon-foresteconomicactivitieshavelimitedtheincomeofforest-dependentcommunities,32EmissionsGapReport2021:TheHeatIsOntherebyincreasingpressureonforestproducts(Golaretal.2020;Rahmanetal.2021).Anotherissuerelatedtoland-useemissionsisthatabouthalfoftheglobalscenariosanalysesandnationalGHGinventoriesusedifferentdefinitionsforanthropogenicremovalsintheland-usesector,resultingindifferentamountsofnetland-usecarbondioxide(CO2)emissionsbeingreported,withahistoricdifferenceofupto4GtCO2e/yearbetweennationalGHGinventoriesandglobalemissionpathwaystudies(Grassietal.2018).Thesolutionsthathavebeenpublishedtoaccountandcorrectforthisdiscrepancyareintegratedinthesestudiesbyapplyingaconstantadjustmenttermoverthe2010–2030period.54.2.2NDCandannouncedpledgescenariosandupdatesTheNDCandannouncedpledgescenariosincludeallthemostrecentNDCs(neworupdatedNDCsandpreviousNDCsforcountrieswherenoupdatesareavailable)aswellasannouncedclimatechangemitigationpledgesfor2030thatcouldbelinkedtoupdatedNDCsandthatfocusonindicatorsortargetsalsoincludedintheirNDCs.TheestimatedimpactofrevisedreductiontargetsintheneworupdatedunconditionalNDCsubmissionsandannouncementslowerstheemissionsprojectionoftheunconditionalNDCscenariobyabout4GtCO2e(about15percent)comparedwiththepreviousNDCs.FortheconditionalNDCscenarioincludingannouncedpledges,asimilarimpactisfound.ThisresultsinamedianestimateofglobalGHGemissionsof52GtCO2eand50GtCO2e,iftheunconditionalandconditionalNDCsarefullyimplemented.Thisisabout4GtCO2elowerthanlastyear’sprojections(basedonpreviousNDCs,seefigure4.1).TheNDCandannouncedpledgescenarioestimateisbasedonfourmodelstudies(ClimateActionTracker,PBL,JRCandClimateResource)(Meinshausenetal.2021),6allofwhichincludetheNDCupdates(asatendofAugust2021),whileonlythefirstthreestudiesconsidertheimpactoftheannouncements.7,8Inaddition,itisbasedonprojectionsoffourmodelgroups(IIASA,theNationalInstituteforEnvironmentalStudies[NIES],thePotsdamInstituteforClimateImpactResearch[PIK]andResourcesfortheFutureandEuroMediterraneanCenteronClimateChange[RFF–CMCC])thathavebeenadjustedtoreflecttheimpactoftheneworupdatedNDCsandannouncedpledges.5ThisapproachisconsistentwiththedetailedadjustmentscalculatedbyGrassietal.(2021),whicharevirtuallyconstantuntil2030foremissionsscenariosinlinewithupdatedcurrentpoliciesorNDCsscenarios.Previousreportsalreadyappliedasimilaradjustmentmethod,whencomparingmodelstudies(suchastheintegratedassessmentmodelstudies)orintheemissionsgapcalculations.Althoughtheliteraturenowprovidesamoreelaborateevidencebaseinsupportofthisadjustment,thisapproachdoesnotresultinshiftsinestimatesoftheglobalemissionsgap.6ClimateActionTracker:https://climateactiontracker.org/global/cat-emissions-gaps/;PBL:www.pbl.nl/ndc;JRC:https://ec.europa.eu/jrc/en/geco.7TheClimateActionTrackeraccountsfortheimpactoftheannouncementofJapanandChina,JRCforChinaandJapan,andPBLincludestheimpactofChina,JapanandtheRepublicofKorea,andalsoincludestheimpactofthelatestNDCofSouthAfrica.8Asthesestudiesdonotfullyaccountforallannouncedpledges,theestimateisslightlylowerthantheestimateinchapter2,butithasbeenroundedtoavoidapparentinconsistencies.4.2.3MitigationscenariosconsistentwiththeParisAgreementandupdatesEmissionprojectionsofthelatestNDCsandannouncedpledgesscenarios,andupdatedcurrentpoliciesscenariosarecomparedtoleast-costmitigationscenariosthatmeetspecifictemperaturetargetsrelativetopre-industriallevels.Here,wecategorizeemissionspathwaysfromtheliteraturebasedontheirprojectedpeakwarmingoutcomesoverthecourseofthiscentury(Huppmannetal.2018b,2018a;Rogeljetal.2018.Seealsochapter3).Wedefinethreescenariosthatdifferintheirestimatedmaximumwarmingoverthecourseofthiscentury(seetable4.1).Thisyear,thescenarioshavebeenupdatedbyre-assessingtheirtemperatureoutcomesbasedontheIntergovernmentalPanelonClimateChange(IPCC)AssessmentReport6WorkingGroupIassessment.Thetemperatureoutcomeofthescenariosisassessedwiththereduced-complexitycarbon-cycleandclimatemodelMAGICC(Meinshausenetal.2011)inasetupthatcapturestheuncertaintiesinradiativeforcingaswellasclimateandcarbon-cycleresponse(Nichollsetal.2021)asassessedincross-chapterbox7.1oftheIPCCSixthAssessmentReport(Forsteretal.2021).Asaresultoftheupdates,globalemissionsin2030consistentwithkeepingglobalwarmingbelow2.0°Cwitha66percentchanceareestimatedat39GtCO2e,whichisabout2GtCO2elowerthaninearlierreports.Similarly,theestimatefor1.8°Cisabout2GtCO2elowerthanthe1.8°Cestimateofpreviousreports.Therearenochangestothe1.5°Cestimate(table4.2).Aspathwaysoftenassumenet-negativeCO2emissionsinthesecondhalfofthecentury,theestimatedglobalwarmingintheyear2100istypicallylowerthanthemaximumwarmingoverthecourseofthetwenty-firstcentury.4.3TheemissionsgapTheemissionsgapfor2030isdefinedasthedifferencebetweenglobaltotalGHGemissionsfromleast-costscenariosthatkeepglobalwarmingto2°C,1.8°Cor1.5°CwithvaryinglevelsoflikelihoodandtheestimatedglobalGHGemissionsresultingfromafullimplementationofNDCsandannouncedreductionpledges.Thissectionupdatesthegapbasedonthescenariosdescribedinsection4.2.33EmissionsGapReport2021:TheHeatIsOnTable4.2providesafulloverviewof2030emissionlevelsfortheeightscenariosconsidered,aswellastheresultingemissionsgapbetweenthescenarioandthe2°C,1.8°Cor1.5°Cpathways.Table4.2.Globaltotalgreenhousegasemissionsin2030underdifferentscenarios,temperatureimplications,andtheresultingemissionsgapScenario(roundedtothenearestgigaton)NumberofscenariosinsetGlobaltotalemissionsin2030[GtCO2e]Estimatedtemperatureoutcomes†ClosestcorrespondingIPCCSR1.5scenarioclassEmissionsGapin2030[GtCO2e]50%chance66%chance90%chanceBelow2.0°CBelow1.8°CBelow1.5°CYear2010policiesi664(60–68)Currentpoliciesii955(52–58)15(12–18)22(19–25)30(28–33)UnconditionalNDCs(updatedNDCsandannouncements)852(49–55)13(10–16)19(16–22)28(25–30)ConditionalNDCsiii(updatedNDCsandannouncements)850(46–52)11(7–13)17(13–19)25(22–28)Below2.0°C(66%chance)7139(33–49)Peak:1.7–1.8°CIn2100:1.3–1.7°CPeak:1.8–2.0°CIn2100:1.5–1.9°CPeak:2.2–2.4°CIn2100:1.9–2.4°CHigher-2°CpathwaysBelow1.8°C(66%chance)2333(27–41)Peak:1.6–1.7°CIn2100:1.2–1.6°CPeak:1.7–1.8°CIn2100:1.4–1.8°CPeak:2.0–2.2°CIn2100:1.8–2.2°CLower-2°CpathwaysBelow1.5°C(66%chancein2100withnoorlimitedovershoot)2625(17–33)Peak:1.5–1.6°CIn2100:1.0–1.3°CPeak:1.6–1.7°CIn2100:1.2–1.5°CPeak:1.9–2.1°CIn2100:1.5–1.9°C1.5°CwithnoorlimitedovershootiAllscenariosrepresentpre-COVID-19estimates.Valuesrepresentthemedianandtenthtoninetiethpercentilerangeacrossscenarios;iiAllscenariosareadjustedtoreflecttheimpactofCOVID-19andrecentpolicies(cut-offdate2020).Valuesrepresentthemedianandtenthtoninetiethpercentilerangeacrossscenarios;iiiValuesrepresentthemedianandtenthtoninetiethpercentilerangeacrossscenarios.†Temperatureoutcomesareestimatedforglobalsurfaceairtemperature(GSAT)withthereduced-complexitycarbon-cycleandclimatemodelMAGICC(Meinshausenetal.2011)inasetupthatcapturestheuncertaintiesinradiativeforcingaswellasclimateandcarbon-cycleresponse(Nichollsetal.2021).Valuesrepresentthemedianandtenthtoninetiethpercentilerangeacrossscenarios.Probabilities(‘chances’)refertopeakwarmingatanytimeduringthetwenty-firstcenturyforthebelow-1.8°Candbelow-2.0°Cscenarios.Whendeployingnet-negativeCO2emissionsinthesecondhalfofthecentury,globalwarmingcanbefurtherreducedfromthesepeakwarmingcharacteristics.Forthebelow-1.5°Cscenario,itappliestotheyear2100,whilethe“noorlimitedovershoot”characteristiciscapturedbyensuringprojectionsdonotexceed1.5°Cwithatleast33percentchanceoverthecourseofthetwenty-firstcentury.Note:Thegapnumbersandrangesarecalculatedbasedontheoriginalnumbers(withoutrounding),andthesemaydifferfromtheroundednumbers(thirdcolumn)inthetable.NumbersareroundedtofullGtCO2e.GHGemissionshavebeenaggregatedwith100-yearglobalwarmingpotential(GWP)valuesoftheIPCCAR4(tobeconsistentwithtable2.4ofIPCCSpecialReportonGlobalWarmingof1.5°C).IPCCSR1.5referstotheIPCCSpecialReportonglobalwarmingof1.5°C.34EmissionsGapReport2021:TheHeatIsOnFigure4.1.Overviewofchangesingreenhousegasemissionsprojectionsfor2030fordifferentscenarios010203040506070=EmissionsGapReport2020=ChangebetweenEmissionsGapReport2020andEmissionsGapReport2021GlobalGHGemissions(GtCO2e/yr)valuesfor2030Year2010policiesCurrentpoliciesUnconditionalNDCsandpledgesConditionalNDCsandpledges2°Cpathways1.8°Cpathways1.5°Cpathways-4-4-2-2-4Note:NumbersinbubblesareroundedtonearestGtCO2e.ThecurrentpoliciesscenarioisestimatedtoreduceglobalGHGemissionsin2030toabout55GtCO2e(52–58),whichis9GtCO2elowerthanintheyear2010policiesscenario.Itisalso4GtCO2elowerthanthemedianestimateofthecurrentpoliciesscenarioofthe2020UNEPEmissionsGapReport.Theimplementationgap,whichisthedifferencebetweenemissionsexpectedunderthecurrentpoliciesscenarioandthoseneededtoachievetheNDCsandannouncedreductionpledges,isestimatedtobe3GtCO2eand5GtCO2efortheunconditionalandconditionalNDCsandpledgescenariosrespectively.Figure4.2illustratestheemissionsgapin2030,highlightingthatwhilethenewandupdatedNDCstogetherwithannouncedmitigationpledgesnarrowthegapslightlycomparedtopreviousNDCs,theyarehighlyinsufficienttobridgethegap.Theytakeonly7.5percentoffprojected2030emissions,comparedtoearlierunconditionalNDCs,whereas30percentisneededfor2°Cand55percentisneededfor1.5°C.Figure4.2showsthatfullimplementationofunconditionalNDCsandannouncedreductionpledgesisestimatedtoresultinagaptoa1.5°Cpathwayof28GtCO2e(range:25–30).Thisisabout4GtCO2elowerthanthegapassessedinthe2020report(UnitedNationsEnvironmentProgramme[UNEP]2020),duetotheupdatedNDCsandannouncedreductionpledges.IftheconditionalNDCsandannouncedreductionpledgesarealsofullyimplemented,theemissionsgapisfurtherreducedbyabout3GtCO2e.TheemissionsgapbetweenunconditionalNDCsandannouncedreductionpledgesandbelow2°Cpathwaysisabout13GtCO2e(range:10–16GtCO2e),whichisabout2GtCO2elowerthanlastyear.WhileNDCandannouncedmitigationpledgesreduceglobalemissionsbyabout4GtCO2ecomparedwithpreviousNDCs,theupdated2°Cscenarioestimatefor2030isabout2GtCO2elowerthaninpreviousEmissionsGapReports(section4.2.3),whichmeansthatthegapisonlyreducedbyabout2GtCO2e.35EmissionsGapReport2021:TheHeatIsOnFigure4.2.Globalgreenhousegasemissionsunderdifferentscenariosandtheemissionsgapin2030(medianestimateandtenthtoninetiethpercentilerange)20.030.040.050.060.070.0201520202025GtCO2e0.010.020.030.040.050.060.070.020152020202520302035204020452050Currentpoliciesscenario2010policiesscenarioRemaininggaptostaywithin2°ClimitRemaininggaptostaywithin2°ClimitConditionalNDCandpledgescenarioUnconditionalNDCandpledgescenario13GtCO2e28GtCO2e25GtCO2eMedianestimateoflevelconsistentwith2°C:39GtCO2e(range33–49)Medianestimateoflevelconsistentwith1.5°C:25GtCO2e(range17–33)GtCO2e112°Crange1.8°Crange1.5°CrangeEstimatedglobalwarmingover21stcenturyCurrentpoliciesscenario:2.8°C(66%chance)UnconditionalNDCandpledgescenariowithnet-zerotargets:2.2°C(66%chance)UnconditionalNDCandpledgescenario:2.7°C(66%chance)GtCO2eTurquoiseareashowspathwayslimitingglobaltemperatureincreasetobelow2°Cwithabout66%chance.Greenareashowspathwayslimitingglobaltemperatureincreasetobelow1.5°Cwitha66%chanceby2100andminimum33%chanceoverthecourseofthecentury.2°Crange1.8°Crange1.5°Crange36EmissionsGapReport2021:TheHeatIsOn4.4TemperatureimplicationsoftheemissionsgapNeithercurrentpoliciesnorthelatestNDCsandannouncedpledgesareconsistentwithlimitingwarmingtothegoaloftheParisAgreement.TounderstandhowfaroffthemarkcurrentpoliciesandNDCsare,estimatedemissionsfortheyear2030foreachofthesescenariosareprojectedoutto2100,andtheirclimateoutcomesassessedwithaclimatemodel(seebox4.1).Thisapproachassumesacontinuationofclimateactionbeyond2030withoutadditionalstrengthening.Extrapolationsuntiltheendofthecenturyareinherentlyuncertainandsubjecttoscenarioassumptionssuchasthelevelatwhichclimateactioncontinuesortechnologycosts.Thisyear,themethodtoextendemissionsto2100andtheclimatemodelsetupusedwasupdatedbasedonimprovedmethodsandthelatestclimateassessmentofIPCCAR6WorkingGroupI.Theseupdatesaloneresultintemperatureprojectionsthatareabout0.2°ClowerthaninpreviousEmissionsGapReports,whichshouldbefactoredinwhencomparingtheresultsbelowwithpreviousestimates.AcontinuationoftheeffortimpliedbythelatestunconditionalNDCsandannouncedpledgesisatpresentestimatedtoresultinwarmingofabout2.7°C(range:2.2–3.2°C)witha66percentchance.9Thisimpliesa50percentchancethat9ThisrangereflectstheuncertaintyduetoextrapolationofGHGemissionsaftertheyear2030andisgivenforthecentralestimateof2030emissionsimpliedbycurrentpolicies,NDCsand/orotherpledges.Takingthehigherorlowerendoftherangesurroundingthe2030emissionsestimateswouldleadtoanadditionalincreaseordecreaseinthetemperatureprojectionsbyabout0.1°C,respectively.Geophysicaluncertaintiesintheclimateresponsearereflectedbytheestimatesfordifferentwarmingpercentiles(50percent,66percentand90percent).warmingiskeptto2.5°C(range:2.0–2.9°C)bytheendofthecenturyanda90percentchancethatitiskeptto3.3°C(range:2.7–3.9°C).AcontinuationofconditionalNDCsandannouncedpledgeslowerstheseestimatesbyabout0.1°Cto2.6°C(2.1–3.1°C),2.4°C(1.9–2.8°C)and3.2°C(2.6–3.8°C),respectively.Bycontrast,acontinuationofcurrentpolicies,whichareinsufficienttomeetthe2030pledges,increasetheestimatesbyabout0.1°Cto2.8°C(range2.3–3.3°C),2.6°C(range2.1–3.0°C)and3.4°C(range2.8–3.9°C),respectively.Net-zeropledges,whichhavebeenannouncedbymanycountries(chapter3),furtherlowerthesetemperatureestimatesmarkedlybyabout0.5°C,iffullyimplemented.Median(50percent),66percentand90percentpercentileglobalwarmingprojectionsofpathwaysassumingunconditionalNDCsandnet-zerotargetswouldthenbecome2.2°C(2.0–2.5°C),2.0°C(1.8–2.3°C),and2.7°C(2.3–3.1°C),respectively.EvenwiththeimplementationofcurrentNDCsandallnet-zerotargets,thereisstillmorethana15percentchancethatglobalwarmingwillexceed2.5°Cbytheendofthecentury,andajustshortof5percentchancethatitwillexceed3°C(figure4.3).Finally,theseestimatedimprovementsfromnet-zerotargetsshouldalsobecaveatedbythefactthatinmanycases,currentNDCsdonotyetsetcountries’emissionsonadirectpathtowardsreachinglonger-termnet-zerotargets(seechapter3).37EmissionsGapReport2021:TheHeatIsOnFigure4.3.Rangeofglobalwarmingoutcomesprojectedifunconditionalnationallydeterminedcontributionsandannouncedpledgescontinue(left)andifadditionallynet-zerotargetsannouncedbycountriesareachieved(right)>4.0°C3.0–4.0°C3.0–4.0°C2.5–3.0°C2.5–3.0°C2.0–2.5°C2.0–2.5°C1.5–2.0°C1.5–2.0°C<1.5°C<1.5°C1.5–2.0°C2.0–2.5°C2.5–3.0°C3.0–4.0°C>4.0°CUnconditionalNDCsandpledgesUnconditionalNDCswithnet-zerotargetsandpledgesNote:Seebox4.1forbackground.Box4.1.EstimatingglobalwarmingimplicationsofNDCsAvarietyofmethodsexisttoextendnear-termemissionsuntiltheendofthecentury(Gütschowetal.2018).WefirstestimatetheglobalcarbonpriceimpliedbytheNDCemissionsreductionsin2030fromano-policiesbaseline.Here,weusethemarkerquantificationofthesecondSharedSocioeconomicPathway,calledSSP2,whichassumesacontinuationofhistoricalsocioeconomicdynamics(Frickoetal.2017;Riahietal.2017),toestimatetherelationshipbetweenemissionreductionsandimpliedcarbonpricesin2030.Subsequently,thecarbonpriceimpliedbytheglobalNDCreductions(e.g.globallyaboutUS$202010in2030forunconditionalNDCs)isextendedoutuntiltheendofthecenturybyapplyingthesameannualgrowthrateasforprojectedglobalgrossdomesticproduct(GDP)underSSP2.BasedontherelationshipbetweenimpliedcarbonpricesandglobalGHGemissionslevelsoverthecourseofthecentury,anemissionstrajectoryisestimatedanddividedintoitsconstitutinggases(Lambolletal.2020).Subsequently,theglobalwarmingoutcomeofeachpathwayisassessedwiththereduced-complexitycarbon-cycleandclimatemodelMAGICC(Meinshausenetal.2011)inasetupthatcapturestheuncertaintiesinradiativeforcingaswellasclimateandcarbon-cycleresponse(Nichollsetal.2021)asassessedincross-chapterbox7.1oftheIPCCAR6(Forsteretal.2021).Countries’net-zerotargets,describedandassessedinchapter3,furtherbringdownemissionsprojectionsoverthecourseofthiscentury(Höhneetal.2021).Theimpactofthisstrengtheningofclimateactionafter2030isalsoestimated.Thisapproachisanupdatecomparedtopreviousreports,bothintermsofthemethodusedtoextendemissionsto2100andtheclimatemodelsetupused.IftheNDCestimatesofthisreportareassessedusinglastyear’smethods,thetemperatureprojectionsforunconditionalNDCswouldbeabout0.2°Chigherthanthisyear’sestimates.38EmissionsGapReport2021:TheHeatIsOnAreCOVID-19fiscalrecoverymeasuresbridgingorextendingtheemissionsgap?Leadauthors:BrianO’Callaghan(UniversityofOxford,UK;HarvardUniversity,USA),Jean-PaulAdam(UnitedNationsEconomicCommissionforAfrica[UNECA],Ethiopia)Contributingauthors:BartholomewArmah(UNECA,Ethiopia),JeanPaulBoketsuBofili(UNECA,Ethiopia),HopestoneKayiskaChavula(UNECA,Ethiopia),FredericHans(NewClimateInstitute,Germany),AndrewPrag(OrganisationforEconomicCo-operationandDevelopment[OECD],France),DavidTritsch(UniversityofOxford,UK)55.1IntroductionInresponsetoCOVID-19,governmentfiscalinvestmentinclimatechangemitigationandadaptationcanbolsterlong-termprosperitybycreatingjobsandacceleratingeconomicgrowthwhilealsomeetingenvironmental,genderandsocialobjectives.Academicevidenceandpoliticalnarrativessupportthisapproach(Barbier2020;O’CallaghanandMurdock2021).Countriesthatfailtocapitalizeonthisopportunityforlow-carbonandclimate-resilienteconomictransformationrisktheireconomicprosperity,environmentalsustainabilityandlong-termsocialcohesion.Despitethis,mostgovernmentshavesofarfailedtoprioritizeatransformativelow-carbonrecovery,withtherelativelyinsignificantlow-carboninvestmentannouncedtodatelikelytomaintaincurrentunsustainablesituations.1AsatMay2021,only2.5–12.1percentofUS$16.7trillionintotalCOVID-19spending(excludingunallocatedEuropeanUnionspending)hasbeenlow-carbonorhadmitigationco-benefits,whileofatotalUS$2.25trillioninannouncedCOVID-19‘recovery’spending,2only17–19percenthasgonetowardslow-carbonspending,representinganinsufficientcommitmenttoalignfiscalpolicieswiththeParisAgreement(Andrijevicetal.2020;O'Callaghanetal.2021;OrganisationforEconomicCo-operationandDevelopment[OECD]2021;VividEconomics2021).Asmallnumberofwealthyeconomiesaccountfortheoverwhelmingmajorityoflow-carbonspending,3withemergingmarket1Low-carboninvestmentisdefinedinthischapterasspendingthatislikelytoreducenetgreenhousegas(GHG)emissions.2Fiscal‘recovery’initiativesaredefinedinthischapterastaxationorexpendituremeasuresthataimtoreinvigorateeconomicgrowth.Recoveryinitiativesaredistinctfrom‘rescue’initiatives,whichactovertheshorttermandaimtokeepbusinessesandpeoplealiveinthefaceofimmediatecrisis.3China,France,Germany,theRepublicofKorea,SpainandtheUnitedKingdomtogetheraccountfor77.4percentoftotallow-carbonspending(O’Callaghan,BirdandMurdock2021a).4Hard-to-abatesectorsarethoseinwhichlow-carbonmeansofproductionaresignificantlymoreexpensiveorlackinginscalabilitythantraditionalmeansofproduction.ManyofthesesectorswillrequiresignificanttechnologicalinnovationtoenableeconomicallycompetitiveGHGabatementwithoutproductivityloss.anddevelopingeconomiesindangerofbeingleftbehind.Althoughlow-carbonrecoveryfundshavesupportedarangeofinitiatives,theyhavesofarbeenskewedtowardscleanenergyandnaturalcapitalinvestments.Thischapterexploresthreequestions:1.HowcouldCOVID-19-relatedpublicspendingbridgetheemissionsgap?Section5.2summarizeskeyprinciplesforlow-carbonpublicspendinginresponsetothepandemic.Thesectionconsiders:(i)short-termrescuespending,tokeepbusinessesandpeoplealive;(ii)longer-termrecoveryinvestment,toreinvigoratetheeconomy;and(iii)reinforcementprocesses,toembedneweconomictrajectoriesfromrecoveryinvestmentintolong-termdevelopmentplans.Targetedlow-carbonrescuespendingincentivizesthedecarbonizationofhard-to-abatesectors4byincludinglow-carbonconditionalitiesorcommitmentsinliquidityandothershort-termbusinesssupportand/orbysustainingtheindustrieslikelytofosterlow-carboneconomicgrowth(Barbier2020).Low-carbonrecoveryinvestmentacceleratesthelow-carbontransitionbothdirectlyandindirectlybyincorporatinglow-carbonincentivesintotraditionalinvestment.Low-carbonreinforcementinitiativesbuildlong-termsupportfortheprojectsandsectorstargetedbylow-carbonrecoveryinvestment,aligninglong-termdevelopmentpathwayswithalow-carbonandclimate-resilienttransformationoftheeconomy.Ateverystage,low-carbonspendingandregulatoryreformsshouldbe39EmissionsGapReport2021:TheHeatIsOnconsideredintandem,assuccessfulimplementationofthelattercanamplifytheimpactoftheformer.2.Whatarethecharacteristicsoffiscalrescueandrecoveryspendingtodateandhowmaytheyimpacttheemissionsgap?Section5.3showsthatlow-carbonrecoverymeasureshavereceivedonly17–19percentoffiscalinvestmentandpolicyfocustodate.Statusquopolicymakingrisksalock-inandpossibleexpansionofhighlevelsofgreenhousegas(GHG)emissionstowardsandbeyond2030.Whileexamplesoflow-carboninvestmentarenumerousandwide-ranging,theylargelycomefromasmallsetofadvancedeconomies.Long-termhumancapitaldevelopment,includingskillsdevelopment,remainsunderprioritized.Withoutasubstantialpivottowardshigherlow-carboninvestment,countriesrisklowereconomicandsocialreturns,aswellasasignificantreboundinGHGemissions(UnitedNationsEnvironmentProgramme[UNEP]2020).3.Dolower-incomenationsfacegreaterbarriersforlow-carbonrecoveryspending?Ifso,whatcanbedone?Section5.4indicatesthatalthoughemergingmarketanddevelopingeconomieshavesuffereddisproportionatelyunderthepandemicandaremoreexposedtoclimaterisk,5Concessionalfinancereferstoloansandotherfinancialinstrumentsthatareextendedontermssubstantiallymoregenerousthanmarketfinancialinstruments.theirrecoveryspendinghasbeenlow,inhibitedbyrestrictedaccesstoaffordablefinance.Aglobalgreenrecoverywillrequireconcessionalfinance,includingdirectgrants,tovulnerablecountriesthataresignificantlyabovecurrentproposals.55.2HowcouldCOVID-19-relatedpublicspendingbridgetheemissionsgap?Thissectiondiscussestrendsinfiscalresponsetowardsrecoveryinvestmentbeforeaskingwhyalow-carbonrecoveryshouldbepursuedandwhatitshouldincorporate.Intheearlystagesofthepandemic,fiscalpackagesfocusedoverwhelminglyon‘rescue’throughtheimmediateprotectionoflives,livelihoodsandbusinesscontinuity.Asdeathrateshavegraduallybeencontrolledinmanyadvancedeconomies,packageshaveslowlyshiftedtoincorporatefundsforreinvigoratingtheeconomythrough‘recoveryspending’(figure5.1).However,recoveryeffortscontinuetobeinhibitedbypersistentCOVID-19outbreaksinmanycountries,particularlyemergingmarketanddevelopingeconomies(InternationalMonetaryFund[IMF]2020).Figure5.1.Announcedrescue,recoveryandunclearspendingforadvancedeconomiesandemergingmarketanddevelopingeconomiesAdvancedeconomiesEmergingmarketanddevelopingeconomiesAnnouncedspending(US$tn)May21Apr21Mar21Feb21Jan21Dec20Nov20Oct20Sep20Aug20Jul20Jun20May20Apr20Mar20Feb20Jan20010864218161412RecoveryRescueUnspecifiedRecoveryRescueUnspecifiedSource:O’Callaghanetal.(2021)40EmissionsGapReport2021:TheHeatIsOnOpportunitiesforrescuespending:Low-carbonrescuespendingcaneaseindustrialdecarbonization,particularlyinhard-to-abatesectors,throughincludinggreenincentivesinbusinessliquiditysupportandothershort-termsupportmechanisms(e.g.reducedtaxation)and/orbydirectingsupporttoindustrieslikelytofostergreengrowth(InternationalRenewableEnergyAgency[IRENA]2020).6Theseprogrammesshouldempowerbusinessestomakecost-efficientchoicestotransitiontocarbonneutralitywithoutcompromisingjobsandlivelihoods.Opportunitiesforrecoveryspending:Growingevidencesuggeststhatlow-carboninvestmentcandeliverstrongereconomicreturnsthanconventionalstimulus,whilestrengtheningclimatemitigation,adaptation,airpollutionreduction,naturalcapitalprotection,7healthoutcomes,inequalityreduction,humanmobilityandbroadsocialprogressandprosperity.8Carbon-intensiverecoverypackagesthatgrowfossilfuelindustrieswithoutconditionsforasustainabletransitionendangereconomicreturnsasfossilfuelassetsbecomedevaluedwithreduceddemandfortheiroutputs(Mercureetal.2018;AnsariandHolz2020;vanderPloegandRezai2020).AnexpertsurveyinHepburnetal.(2020)identifiedtraditionaltransportandenergyinfrastructureinvestmentasthemostharmfulrecoverypoliciesforlong-termGHGemissions,althoughthisanalysisdidnotconsiderarmedforcesinfrastructurespending,whichisalsoharmfulcomparedwithothers(O’Callaghan,MurdockandYau2021).Someofthemostattractiverecoverymeasuresforreducingemissions–thosewhichbalancethepotentialtospureconomicgrowthinacontractionaryenvironmentandthepotentialtomitigateemissions–includeelectricvehicleincentivesandpublictransportmodernization,cleanenergyinfrastructureinvestments,energyefficiencyupgrades,naturalcapitalinvestmentsandcleanresearchanddevelopmentprogrammes(Barbier2020;Garrett-Peltier2017;UnitedKingdom,ClimateChangeCommittee6Publicly-financedliquiditysupportandothershort-termbusinesssupporthelpbusinessesmeettheirimmediatecostsandcontinueoperations,withoutthethreatofexpeditiousliquidation.Low-carbonconditionalitiesmayrequirebusinessestotakeenvironmentalcommitmentsasaconditionofreceivingpublicfunds(orhavingalowertemporarytaxorexpenseload).Sincethesemeasuresincentivizeinnovation,theymayincreasetheeconomicimpactoftaxpayerspendingwhilealsodeliveringenvironmentalandsocialbenefits(O’CallaghanandHepburn2020).7Naturalcapitalreferstoecosystems,biodiversehabitats,cleanwaterandair,productivesoilsandastableandresilientclimate.8Hepburnetal.(2020),OECD(2020a),Georgieva(2021),O’CallaghanandMurdock(2021)andUnitedNationsEconomicCommissionforAfrica[UNECA](2021),amongothers,expandonexistingevidencetosupporteconomic,environmentalandsocialnarrativesforlow-carbonpublicinvestment.9SeeInternationalEnergyAgency[IEA](2020);Mallietetal.(2020);Pollittetal.(2020);VividEconomicsmodellinginO’Callaghan,BirdandMurdock(2021a);VividEconomicsmodellinginO’Callaghan,BirdandMurdock(2021b);Kiss-Dobronyietal.(2021);SchreinerandMadlener(2021).Ongoinginitiativestoimprovecomparativemodellingmethodsalsopresentasimilarfinding(Batinietal.2021).10Forinstance,inrenewableenergygeneration,streamlinedapprovalprocesses,contractsfordifferencemodels,andfeed-intariffsdrasticallyaccelerateduptakeinpre-pandemictimes(Haasetal.2011;Schumacher2019;WelischandPoudineh2020).2020;Hepburnetal.2020).ContinentalunionsandregionaleconomiccommissionsoftheUnitedNationshavehighlightedsimilarpriorities(seeappendixB.1).Althoughtheaccessibilityoftheseoptionsdependsonthedevelopmentoftechnologicalinfrastructureandtheavailabilityofnaturalandhumanresources,input-outputmodellingindicatesthatlow-carboninvestmentcouldgeneratesignificantlymorejobsandgreatereconomicvaluethantraditional‘dirty’and‘neutral’alternatives.9Thisistrueforbothadvancedeconomiesandemergingmarketanddevelopingeconomies.Opportunitiesforreinforcementspending:Theroleoflow-carbonreinforcementmeasuresfollowingrecoveryremainslargelyundiscussedinacademicandprofessionalliterature.However,asCOVID-19spendingbecomesintegratedintroregulatorybudgetaryprocesses,itbecomesincreasinglylessdistinguishablefromnormal‘peacetime’spending.Goingforward,sustainability-proofingtheentirebudgetaryprocessandincreasingpolicycoherenceacrosssectorsandlevelswillbecrucialtomaximizetheimpactofalow-carbonrecovery.Thiscouldbeachievedthroughimplementinggreenbudgettaggingprocesses(Eltokhyetal.forthcoming)orapplyingmoreadvancedgreenpublicfinancialmanagementframeworks.Non-governmentalandacademicadviserscollectivelyproposeatleastsevenkeyprinciplesfordesigningalow-carbonfiscalresponsetothepandemic,assummarizedinfigure5.2.Consensusopinionsuggeststhatpolicydesignshouldbeconsultative,evidence-basedandgender-sensitive,whileensuringpromptimplementationthatisconsiderateofpandemicrealities.Importantly,fiscalactionrepresentsonlyoneofseveralmechanismsavailabletoadvanceclimateactionandstimulateeconomicgrowthfollowingCOVID-19.Regulatoryandmarketinterventions,amongothers,canplayakeyrole.10Fiscalmeasuresarealsolikelytoprovemosteffectivewhencombinedwithappropriateregulatoryandmarketinterventions(OECD2020b).41EmissionsGapReport2021:TheHeatIsOnFigure5.2.PrinciplesforagreenrecoveryUpholdingcommitmentsNeedtouphold2030SDGsandtheParisAgreementFiscalspendingasanindicatorofprogressagainstNDCsBuildingresilienceMitigatingclimateriskbyemphasizingnature-basedsolutionsInvestmentineffectivedisastermanagementCentringparticipationProtectingthemostvulnerableandsynthesizingthediverseprioritiesofdifferentsocioeco-nomicgroups,genders,ethnicitiesandagegroupsSupportingtheprivatesectorSmallandmedium-sizedenterprisesandinformalenterprisesarevulnerable,accountformostofglobalemploymentandcanrapidlytakeupgreeninnovationsCreatingalliancesBuildingtradeandinnovationnetworkscansupportrecoverySharedgovernanceapproachescancreatefiscalspaceforrecoveryindevelopingcountriesAcceleratingthetransitionStimulatingmarketswherethetransitioniswellunderway(e.g.renewableenergy)LimitingfossilfuelsubsidiesandmakingdirtyenergybailoutsconditionalongreentransformationsPrioritizingtransparencyTransparentandinclusivepolicyconsultationisessentialSpendingshouldnotundermineenvironmentalprotectionsorgenerateunsustainabledeficitsSources:SynthesizedfromButterworth(2020);C40(2020);Corkaletal.(2020);GreenGrowthKnowledgePlatform(2020);PartnersforInclusiveGreenEconomies(2020);UnitedKingdom,ClimateChangeCommittee(2020);OceanConservancy(2021);TheLancetCOVID-19CommissionTaskForceonGreenRecovery(2021)11Proposedeconomicindicatorsincludeshort-andlong-termmultipliereffectsandlabourimpacts,environmentalindicators,suchasGHGemissionsandairandwaterquality,andsocialindicators,suchascost-of-living,inequality,publichealthandgenderequityimpacts(Jotzo,LongdenandAnjum2020;WorldBank2020).Tosupportaccountabilityandtransparency,low-carbonrecoveryinvestmentofallkindsshouldincludeappropriatemanagementstructuresformonitoring,reportingandverifyingtheeffectiveimplementationanduseofrecoveryfunds(Agrawalaetal.2020),aswellasdesignatedfundsandstandardsforex-postimpactassessment.Suchmeasuresmayalsoimproveunderstandingoftherelativestrengthsoflow-carbonfiscalinvestmentoveralternatives.11Oversighttools,suchasthe‘donosignificantharm’principleincludedintheEuropeanUnion’sRecoveryandResilienceFacilityregulation,cancountermeasuresthatendangerenvironmentalobjectives(EuropeanCommission2021).5.3.Whatarethecharacteristicsoffiscalrescueandrecoveryspendingtodateandhowmaytheyimpacttheemissionsgap?Thissectionprovidesahigh-levelassessmentofthecharacteristicsofglobalCOVID-19rescueandrecoveryspendingsofarwithrespecttomitigation.Acrosscountriesanddatasources,severalprimarythemeshaveemerged:1)Only2.5percentofUS$16.7trillionintotalCOVID-19fiscalspending(excludingunallocatedEuropeanUnionspending)hasbeenlow-carbon,withonly17–19percentofatotalUS$2.25trillioninannouncedCOVID-19recoveryspendinglikelytoreduceGHGemissions(O’Callaghanetal.2021).Sevencountriesaccountforalmost90percentofthisspending:China,France,Germany,Japan,theRepublicofKorea,SpainandtheUnitedKingdom(figure5.3).ThepercentageofrecoveryspendingthatislowcarbonhasslowlyincreasedsinceEmissionsGapReport2020(UNEP2020),perhapsdriveninpartbyabetterunderstandingofthepotentialforlow-carboninvestmentstodeliverstrongeconomic,environmentalandsocialreturns.High-carbon,neutralandunclearspending(87.9–97.5percentoftotalspending)eitherworsensormaintainstheunsustainablestatusquoofthecurrentglobalemissionstrajectory(O’Callaghanetal.2021;OECD2021;VividEconomics2021).42EmissionsGapReport2021:TheHeatIsOnFigure5.3.Non-exhaustiveoverviewoftotalfiscalrescueandrecoverymeasuresofG20memberswithhigh-carbon,neutralandlow-carbonimpactsasashareof2020grossdomesticproduct12GROGROOECDGROOECDGROOECDGROOECDGROOECDE3GGROOECDE3GGROOECDGROOECDGROOECDE3GGROOECDGROGROOECDGROGROGROOECDGROGROOECDGROOECD10%10%0%0%ArgentinaAustraliaCanadaChinaFranceGermanyIndiaIndonesiaItalyJapanMexicoRussianFederationSaudiArabiaSouthAfricaTurkeyUKUSARepublicofKoreaBrazilTotal(US$bn,GRO)%ofGDP%ofGDPHighlynegativeUS$354.98bnNegativeUS$327.16bnRelativelyneutralUS$13,706.29bnPositiveUS$15.3bnHighlypositiveUS$61.71bnUnclearUS$2,112.94bnNotes:GRO–GlobalRecoveryObservatoryoftheUniversityofOxford,UNEP,GreenFiscalPolicyNetworkandUnitedNationsDevelopmentProgramme(UNDP);OECD–OECDGreenRecoveryDatabase;E3G–GreenRecoveryTrackerofThirdGenerationEnvironmentalism(E3G)andWuppertalInstitute.12DatafortheoverallspendingbararefromtheGlobalRecoveryObservatory,asitistheonlycurrenttrackerthataccountsfor‘neutral’measures.TheInternationalMonetaryFund(IMF)andClimateActionTracker(CAT)havediscontinuedtheirtrackerssincethereleaseofthe2020EmissionsGapReport.TheGreennessofStimulusIndexfromVividEconomicshaschangeditsmethodology,suchthatitnolongerdirectlyassessespolicy-levelclimateimpacts.Instead,theGreennessofStimulusIndexassignsa‘greennessvalue’(positiveornegative)toeachsectorofeverytrackedcountry,withthefinalindexforeachcountrybeinganaverageofsectoralimpact.Asthismethodologyisnotcomparablewithothertrackers,VividEconomicsadvisedexcludingtheGreennessofStimulusIndexinformationfromthefigure.TheIEA’sSustainableRecoveryTrackerandtheEnergyPolicyTrackeronlycoverenergyspendingandarethereforeexcludedfromthisanalysis.Manydiscrepanciesbetweentheincludedtrackersrelatetokeydifferencesinmethodology:forinstance,theGreenRecoveryTracker(E3Gundated)doesnotincludecertaintypesofrescuespending,whiletheGlobalRecoveryObservatory(O’Callaghanetal.2021)accountsforallfiscalmeasures.Trackersalsovaryintheirdefinitionsof‘low-carbon’:onemeasuremayreceivealow-carbontagbyonetrackerandaneutraltagbyanother,resultinginsubstantialdifferencesinspendingrecordedineithercategory.AcomparisonoftrackersandtheirmethodologiescanbefoundinappendixA.3.43EmissionsGapReport2021:TheHeatIsOn2)Low-carbonfiscalinvestmenthascoveredawiderangeofpolicytypes.Over500low-carbonrescueandrecoverymeasureshavebeenintroducedworldwide,coveringmostemergingandestablishedlow-carbonindustries(figure5.4).Therangeofspendinghasbeennotablywiderinadvancedeconomies,withemergingmarketanddevelopingeconomiesfocusingtheirlow-carbonrecoveryfundsoncleanenergygenerationandnaturalcapitalinvestments.Spendingonworkerretraininginitiativesremainslowacrosscountries,indicatinganinsufficientfocusonlong-termhumancapitaldevelopment.Aminorportionofinvestmentinwhathavetraditionallybeenconsidered‘neutralsectors’includeaccompanyinglow-carbonincentives(appendixB.2listsafewexamplesofthistypeofinvestment).13Leaders’areclassifiedashavingspentabove1percentofgrossdomesticproduct(GDP)onfiscalrecoveryandabove30percentofthisonlow-carbonmeasures(O’CallaghanandMurdock2020).TheGreennessofStimulusIndexscoreiscalculatedbycombiningtheflowofstimulusintofivekeysectorswithanindicatorofeachsector’senvironmentalimpact(VividEconomics2021).3)Internationaldisparitiesaresignificantinbothtotalspendingandlow-carbonspending.Somecountriesarealreadywellintotheireconomicrecoverywhileothershavebeenunabletoactatall,constrainedbylowaccesstocapitalandcontinuingCOVID-19mobilityrestrictions.Ofthosewhohavespentsignificantly,somehaveintegratedgreenprioritiestoaconsiderabledegree,withothershavingfailedtoconsiderenvironmentalconcernsinanyway.TheGlobalRecoveryObservatoryhasfoundthatCanada,Denmark,Finland,France,GermanyandNorwaycanbeconsideredas‘leaders’inlow-carbonrecovery,withtheirlow-carbonspendingasashareofrecoveryspendingrangingbetween39and75percent.Spain,SwedenandtheUnitedKingdomalsorankhighlyaccordingtoVividEconomics’GreennessofStimulusIndex.13Figure5.4.GlobalrecoveryspendingasofMay2021acrosssectorsbyregion(US$billions)050100150200US$250bnCleanenergy(4.1%)Naturalinfrastructure(3.8%)Cleantransport(3.3%)Traditionalenergy(1.6%)Armedforces(0.8%)Traditionaltransport(9.2%)CleanR&D(1.6%)Energyefficiency(2.2%)EuropeAfricaAsiaLatinAmerica&theCaribbeanNorthernAmericaOceaniaLow-carbonmeasuresHigh-carbonmeasuresFigure5.4Note:Low-carboninitiatives(top)andhigh-carboninitiatives(bottom).Source:O’Callaghanetal.(2021)Aschapter2shows,globalemissionsdroppedin2020,butareexpectedtobouncebackin2021.Studiesontheimpactofannouncedfiscalinvestmentonglobalemissionssuggestthatdecisionsmadesofarwillmaintaintheunsustainabletrajectoryofpre-pandemiceconomies(Forsteretal.2020;Mallietetal.2020;Melesetal.2020;Pollittetal.2020;IEA2021;Shanetal.2021).Inlinewiththe2020EmissionsGapReport,thestudiessuggestthatamorecarbon-intensiverecoverywouldincreaseemissionssubstantiallyinthemediumtolongterm,whilealow-carbonrecoverywouldsignificantlyreduceemissions(seealsoappendixB.3).5.4.Dolower-incomenationsfacegreaterbarriersforlow-carbonrecoveryspending?Ifso,whatcanbedone?ThissectiondescribesthedisproportionatelynegativeimpactsofCOVID-19onvulnerablenations.Itthendiscussestheneedforsignificantlyincreasedinternationalaidtosimultaneouslysupporteconomicrecovery,long-termeconomicdevelopmentandclimatepriorities.44EmissionsGapReport2021:TheHeatIsOn5.4.1.VulnerablenationsarebeingleftbehindTheCOVID-19crisishashadanespeciallynegativeimpactonvulnerablenations:globalextremepovertyrosein2020forthefirsttimeinover20years,withanestimated120millionadditionalpeopleestimatedtobelivinginpovertyduetothepandemic(WorldBank2021a).Foreigndirectinvestmentfellby8percentindevelopingcountriesin2020comparedwith14Foreigndirectinvestmentreferstocross-borderinvestmentwhereaninvestorestablisheslastingfinancialinterestinandinfluenceoveranenterprisedomiciledinanothereconomy.15Althoughmanyadvancedcountrieshaveannounceddramaticincreasesinexpenditureatnear-orbelow-zerofinancingcosts(Blanchard2019),thesameisnottrueofmostemergingmarketanddevelopingeconomies.Severepandemic-inducedeconomiccontractionsinmostemergingmarketanddevelopingeconomieshavecausedadramaticriseindebt-to-GDPratios(IMF2021b),temporarilyincreasedcreditdefaultinsurancepremiumsasmeasuredbycreditdefaultswapspreads(CouncilonForeignRelations[CFR]2021)andreducedcurrentaccountbalances(WorldBank2021b),leavingemergingmarketanddevelopingeconomiesintheLatinAmericaandtheCaribbean,andEurope,theMiddleEastandAfricaregionswithhistoricallylowcreditriskratings(S&P2021a;S&P2021b).Acrossbothadvancedeconomiesandemergingmarketanddevelopingeconomies,climatechangeislikelytoexposesomeformsofdebttoevenmorerisk,particularlydebttofinanceclimate-exposedinvestmentssuchasagriculture(Dibley,WetzerandHepburn2021;EuropeanCentralBank2021).2019,drivenbya15.6percentdeclineinAfricaanda45.4percentdeclineinLatinAmericaandtheCaribbean(UnitedNationsConferenceonTradeandDevelopment[UNCTAD]2021).14Despitethesetrends,COVID-19spendinghasbeenfarlowerinlow-incomeeconomies(~US$60perperson)thanadvancedeconomies(~US$11,800perperson;seefigure5.5).Figure5.5.COVID-19-relatedspendingpercapitaacrossdevelopmentcategories(US$)AdvancedeconomiesUS$11,826perpersonEmergingmarketanddevelopingeconomiesUS$578perpersonLow-incomeeconomiesUS$57perpersonSource:O’Callaghanetal.(2021)UnequalaccesstofinanceisakeydriverofdisparitiesinCOVID-19spendingbetweenhigh-andlow-incomenations(O’CallaghanandMurdock2021).15In2020,developmentpartnerscommittedUS$89.5billiontosupportAfricannationsinresponsetoCOVID-19,ofwhichUS$59.5billionhasbeendisbursed(figure5.6).Thisrepresentsjust0.4percentoftotalglobalCOVID-19spending.Withoutasubstantialincreaseinforeignaid,thedifferenceinspendingbetweenadvancedeconomiesandemergingmarketanddevelopingeconomieswillexacerbategapsindevelopment,whilealsorestrictingprogressagainstclimatechange.Emergingmarketanddevelopingeconomiesarealsolikelytobecometheworld’stopGHGemittersifclimatefinancedoesnotsignificantlyincrease(WorldResourcesInstituteundated),allwhiledisproportionatelysufferingtheburdenofclimatechange,whichhashistoricallybeencausedbyhigh-incomeeconomies(seeIMF2021a).45EmissionsGapReport2021:TheHeatIsOnFigure5.6.FundingcommitmentsanddisbursementstoAfricabydevelopmentpartnersin2020–2021(US$billions)Multilateraldevelopmentbanks(MDBs)US$60.1bnKey:Multilateralfinancialinstitutions(MFIs)U$29.4bnGavi,theVaccineAllianceUS$0.1bnGlobalPartnershipforEducationUS$0.3bnMDBsUS$18.8bnMFIsUS$24.9bnWorldBankDebtServiceSuspensionInitiativeUS$9.0bnActualsCommitmentsEuropeanUnionUS$6.4bnWorldBankAfricanDevelopmentBankIslamicDevelopmentBankArabBankforEconomicDevelopmentInternationalMonetaryFundAfricanExport-ImportBankArabMonetaryFundWBDebtServiceSuspensionInitiativeEuropeanUnionGaviVaccineAllianceGlobalPartnershipforEducationSource:Non-publicUNECAanalysis(2021)16Debtforclimate-resilienceswapsexchangethecancellationofadevelopingcountry’spublicdebtforincreasedinvestmentinclimate-relatedprojectsinthatsamecountry.Theseinstrumentsofferavehicleforgeneratinglow-carbonrecoveryinvestmentinsectorsthatfacilitatethetransitiontolow-carbongrowth.5.4.2.HowtosupportvulnerablenationsAsinadvancedeconomies,low-carboninvestmentinemergingmarketanddevelopingeconomieshasthepotentialtoshortenthedurationofCOVID-19impacts,addressclimateconcernsandsetstronglong-termdevelopmentpathways.Naturalresourceendowmentsinmanylow-incomenationsmakeinvestmentsinrenewableenergygenerationfacilitiesandnaturalcapitalsolutionsparticularlyattractive(Kim2020).Byprioritizinglocalsupplychains,long-termpartnershipsbetweenemergingmarketanddevelopingeconomiesandhigh-incomeeconomiescanenablesustainablegrowthandbuildfuture-proofinfrastructure.Wealthiereconomiescouldsupportvulnerablenationsinseveralways:●DebtforgivenessBasedonIMFandWorldBankdebtsustainabilityanalysis,debttreatments,includingdebtwrite-offs,mustbeconsideredforvulnerablecountries.Debtreliefprogrammes,includingdebt-for-climateswaps,couldhelpsupportlow-carbonrecoveryandatransitiontolow-carbongrowth.16Ahaircutof10percentindebtrepaymentscouldresultinsavingsofUS$100billionforreinvestmentinlow-carbonrecoveries(Jensen2021).Debtrestructuring,includingprivatedebt,throughnewbondissuancesalignedwiththeSustainableDevelopmentGoals(SDGs)andtheParisAgreementcouldhelpaverta‘lostdecade’andprovidefiscalresourcesforinvestmentinalow-carbonrecovery(Volzetal.2021).●DirectgrantsandconcessionalfinanceNewlow-carbonandclimate-resilientrecoveryinvestmentscanimproveinclusionwhileadvancingprogressontheSDGs.Advancedeconomiescanacceleratethisbyprovidingresourcescommensuratewiththescaleoftherequiredtransformation,i.e.significantlymorethanthecommitmentsagreedatthesixteenthUnitedNationsClimateChangeConferenceoftheParties(COP16)ofUS$100billionperyear46EmissionsGapReport2021:TheHeatIsOn(UnitedNations2010).Disjointedinterventionsmaywidenfurtherdivergence.●ConcessionalfinanceforgreenandbluebondsTheproceedsofgreenandbluebondissuancesrespectivelyfinanceenvironmentally-friendlyprojectsandoceanconservationprojects,oftenunlockingnewfinancetoadvanceclimategoals(Banga2018;WorldBank2008).Greenandbluedebtmarketsaregrowinginemergingmarketanddevelopingeconomies,yetseveralchallengesremain,includingonlyasmallpricingbenefitofgreenandbluebondsoverregularbonds(DoranandTanner2019;OtekNtsamaetal.2021).17Foreignmonetaryauthoritiesandgovernmentscouldcommittopurchasinggreenandbluebondsatlowerinterestratesinemergingmarketanddevelopingeconomies(Liaw2020).Robust,standardizedandstringentcertificationandmonitoringsystemscouldprovidegreatercredibilityforsuchissuances.●GuaranteeingprivatesectordebtTheimpactofpublicinvestmentinclimateresilienceandmitigationcanbesignificantlyimprovedby‘crowding-in’additionalprivatesectorresources.Blendedfinanceandpartialguaranteeshaveakeyroleinsupportingthisforemergingmarketanddevelopingeconomies,particularlyfollowingthepandemic-inducedcrashininternationalprojectfinanceandotherformsofforeigndirectinvestment(UNCTAD2021).●RedistributingmultilateralfinancetovulnerablenationsTheproposedIMFissuanceofUS$650billioninnewspecialdrawingrightscouldstronglysupportalow-carbonrecoveryiffundsaredirectedtofuture-orientedlow-carbonandclimate-resilientinvestments.On-lendingasubstantialamountofsuchfundstotheworld’smostvulnerablecountriescouldsignificantlyenhancetheissuance.Withoutsuchanaction,only3.2percentoftheissuancewillbedirectedtolow-incomecountries(TheEconomist2021).WhilethecurrentIMFcallforUS$100billiontobeon-lentispositive,itremainsinsufficientgiventheextremedisparityinfiscalspacebetweenadvancedandvulnerableeconomies.AppendixA.4comparesalternativeapproachesthatcouldbeimplemented.17Forexample,Egypt’sOctober2020issuanceofaUS$750milliongreenbondwasbroadlypricealignedtoitsnormalstandardbondissuances(LondonStockExchange2020).18Carbonborderadjustmentmechanismsactto“equalisethepriceofcarbonbetweendomesticproductsandimports”toeliminatefinancialincentivestorelocateproductionoutsideofregionswithstrongclimatecontrols(EuropeanCommissionundated).19Emergingtools,suchasthesustainabledevelopmentandclimateactiongreenrecoveryscreeningtool(SCREEN,oftheNewClimateInstitute)canassistinidentifyinghigh-potentialopportunities.●Considerationsforcarbonborderadjustmentmechanisms18Carbonborderadjustmentmechanisms,suchasthoseproposedbytheEuropeanUnion,couldprovidehighlyeffectivetrade-basedregulationstodrivedownemissionsandrewardsustainablesupplychains.However,althoughsuchmechanismsareprimarilyintendedasprotectiveenvironmentalmeasures,theirunequaltradeimplicationsandpotentiallyhighburdenonvulnerablenationsmustbeacknowledged.Ifcarbonborderadjustmentmechanismsareimplemented,standardsandcontrolsmustbedevelopedthatbothsupportglobalenvironmentalneedsanddevelopmentprioritiesofvulnerablenations.Thesemechanisms(andtheirstandardsandcontrols)mustbeimplementedwithsignificantfinancialandtechnicalresourcestosupportcapacity-buildinginvulnerablenations(seeGore2021).Toensureasuccessfulsustainableandinclusivetransition,emergingmarketanddevelopingcountriesrequiresignificanttechnologytransferandcapacity-buildinginadditiontofinancialsupport,needsthatshouldbereflectedinupdatednationallydeterminedcontributions(NDCs).Supportforlow-carbonrecoveryinemergingmarketanddevelopingeconomiesoftenreliesdirectlyonthenation’sdemonstratedinteresttopursuepublicpolicyreformsthatareconsistentwiththeParisAgreementgoals,suchas,forexample,considerationofandactiononcarbonpricing,fossilfuelsubsidiesreform,greenbudgetingsystemsandregulationsforfinancialsectorgreening.1947EmissionsGapReport2021:TheHeatIsOnTheroleofanthropogenicmethaneemissionsinbridgingtheemissionsgapLeadauthors:DrewShindell(DukeUniversity,USA),MarielleSaunois(UniversitédeVersaillesSaint-Quentin[UVSQ],LaboratoiredesSciencesduClimatetdel'Environnement[LSCE],France)Contributingauthors:DominikBrunner(SwissFederalLaboratoriesforMaterialsScienceandTechnology[EMPA],Switzerland),LenaHöglund-Isaksson(InternationalInstituteforAppliedSystemsAnalysis[IIASA],Austria),KevinKarl(FoodandAgricultureOrganizationoftheUnitedNations[FAO],Italy),EuanNisbet(RoyalHolloway,UniversityofLondon,UK),StefanSchwietzke(EnvironmentalDefenseFund[EDF],USA),FrancescoTubiello(FAO,Italy)66.1IntroductionMethaneemissionsarethesecondlargestcontributortoglobalwarmingtodateaftercarbondioxide(CO2),accountingforaboutonethirdofthewarmingimpactofallwell-mixedgreenhousegas(GHG)emissionsand45percentofthenetwarmingimpactofallanthropogenicactivitiesin2019(IntergovernmentalPanelonClimateChange[IPCC]2021).Alongwithblackcarbon,troposphericozoneandsomehydrofluorocarbons(HFCs),methaneisashort-livedclimatepollutant(SLCP),aclassthathasmuchgreaterwarmingimpactspertonthanCO2,butamuchshorteratmosphericresidencetime.MethaneaccountsformorethanhalfofthewarmingofallSLCPs.Atmosphericobservationsshowthatemissiongrowthrateshaveacceleratedoverthepast15years,withmethaneatmosphericconcentrationsreaching1,879partsperbillionin2020onannualaverage,whichwas6percenthigherthanin2000(Dlugokenckyundated)and260percenthigherthanduringpre-industrialtimes(WorldMeteorologicalOrganization[WMO]2020).Anthropogenicemissionsaccountforroughly60percentoftotalmethanefluxestotheatmosphere,amountingtoaround365±30megatonsofmethane(MtCH4)/year.Approximately35percentcomefromfossilfuels(twothirdsfromoilandgasandonethirdfromcoal),40percentfromagriculture(threequartersfromentericfermentationandmanuremanagementandonequarterfromrice)and20percentfromwaste(mostlylandfillsandsolidwaste),withtheremaining~5percentemittedthroughbiofuelandbiomassburning(Saunoisetal.2020).Theremainingroughly40percentoftotalmethaneemissionsaregeneratedbyseveralnaturalsources:inlandfreshwaters(includingwetlands,lakes,reservoirsandrivers),geologicalreleases,wildanimals,termitesandpermafrost.Sectoralpartitioningofmethaneemissionsvariesgreatlyamongcountries/regionsandlargeuncertaintiesremaininbothanthropogenicandnaturalemissions(figure6.1).Overthelasttwodecades,themaincauseofincreasingatmosphericmethaneislikelyincreasinganthropogenicemissions,withhotspotcontributionsfromagricultureandwasteinSouthandSouth-EastAsia,SouthAmericaandAfrica,andfromfossilfuelsinChina,theRussianFederationandtheUnitedStatesofAmerica(Jacksonetal.2020).Emissionsfromnaturalsourcesmayalsobeincreasing,aswetlandswarm,tropicalrainfallincreasesandpermafrostthaws.Thesizeofmethanesinks(mainlyoxidationintheatmosphere),andhowthisvariesovertime,remaindifficulttopredictandstudy.UnlikeCO2,littleattentionhasbeengiventocapturingmethanefromtheair,andfurtherassessmentofthefeasibilityofmethaneremovalisthereforerequired(Jacksonetal.2019).Althoughmethaneemissionreductionsareanecessarypartoflong-termmitigationstrategiesalongsideCO2reductions(Rogeljetal.2018),mitigatingmethaneemissionswouldespeciallycontributetoreducingclimatechange-relateddamagesinthenearterm,whilereducingthelevelofeventualtemperaturestabilizationanddecreasingpeakwarmingduringthiscentury.Asaresult,therehasbeenincreasedfocusinrecentyearsontheimmediateneedandopportunitytoreducemethaneemissions.TheUnitedNationsEnvironmentProgramme(UNEP)andClimateandCleanAirCoalition(CCAC)releasedaGlobalMethaneAssessmentinMay2021,whichanalysedthebenefitsofreducingmethaneemissions,the48EmissionsGapReport2021:TheHeatIsOnpoliciesandcostsofmitigationactionsandthereductionsneededtomeetParisAgreementgoals(UnitedNationsEnvironmentProgramme[UNEP]andClimateandCleanAirCoalition[CCAC]2021).Severalgroupshaverecentlyanalysedabatementpotentialsformethane,whileothershavebothexaminedmitigationanddescribedtheimpacts1Thetroposphereisthelowestleveloftheatmosphere,whichincludessurfaceair.ofsuchmitigationontheabilitytomeetclimatetargets(Nisbetetal.2020;Ockoetal.2021;UNEPandCCAC2021).Themainfindingsofthesestudiesareassessedbelow,withsomeelementshighlightedandimplicationsfornationallydeterminedcontributions(NDCs)explored.Figure6.1.Averagemethaneemissionsfor2008–2017inMtCH4/yearfor18continentalregions010203040BrazilCanada010203040CentralAmerica010203040EquatorialAfrica010203040Europe010203040MiddleEast010203040NorthernAfrica010203040NorthernSouthAmerica010203040Oceania010203040RussianFederation010203040SouthAsia010203040SouthernAfrica010203040South-WesternSouthAmerica010203040USA010203040CentralAsia010203040China0010203040KoreaandJapan010203040South-EastAsia010203040TDWETLBUWETLTDFOSBUFOSTDAGRIWBUAGRIWNote:Emissionsareshownforthreemainemissioncategories:wetlands(WETL),fossilfuel-related(FOS)andagricultureandwaste(AGRIW).Colouredbarsrepresenttheminimumandmaximumrangeofavailableestimatesfromtop-down(TD)andbottom-up(BU)approaches.Blackdotsshowtheaverageforeachapproach(basedonSaunoisetal.2020datasets).Thecoloursinthemapindicateregionsonly.6.2OptimizingmethaneemissionreductionsThelevelofmethaneemissions(andothershort-livedsubstances)atthetimeofreachingnetzeroforlong-livedGHGswillplayanimportantroleindeterminingthelevelatwhichtemperaturesstabilize.Methanestabilizationatalevelgreaterthanthepre-industriallevelwillmeanalong-termcommitmenttowarmingrelativetothepre-industriallevel,whereaschangesinmethaneemissionswillcontributefurthertofuturetemperaturechanges.AsaGHGthatdoesnotaccumulatesemi-permanentlyintheatmosphere,achievingnet-zeromethaneemissionsisnotrequiredforclimatestabilization,norisitexpected,inmarkedcontrasttothesumofCO2andnitrousoxide(N2O),forwhichnet-zeroemissionsarerequiredforstabilization(Rogeljetal.2018;seealsochapter3).Methaneabatementwouldaffectwarmingratesinthenearterm,resultinginbenefitsforecosystemsandtheabilityofhumanstoadapt.Asaprecursoroftroposphericozone,1whichcanbetoxictobothhumansandplants,methaneemissionsaffectpublichealthandcropyieldsviaairpollution.Definingtheoptimalpathformethaneemissionreductionsisthereforearguablymoresuitedtoamultiple-benefitsanalysisthanotherGHGs,ratherthanananalysis49EmissionsGapReport2021:TheHeatIsOnonlydefinedbyaclimatemetric(thoughotherGHGsmayalsohaveco-benefitsthataffectairpollutionandhealth).Capturedmethanehasaclearuseandmarketvalueasnaturalgas.Asaresult,manymethanereductionmeasureshaveloworevennegativecosts,withmanymodelsexaminingleast-costpathwaystomeetlowwarmingtargetsreducingmethanesharplyinthecurrentdecade(Harmsenetal.2019a;UNEPandCCAC2021),thoughsuchreductionsarenotyetoccurring.Dependingonprogressinmitigatingemissionsoflong-livedGHGs,rapidreductionsofmethanearealsolikelytoplayaroleinlimitingpeakwarming(chapter3).ThatroledependsheavilyonhowquicklyemissionsofCO2arereduced,howmuchCO2removalisdeployed,andontheemissionstrajectoriesofothershort-livedclimateforcers.6.3Short-andlong-termmitigationpotentialsTheUNEPandCCACGlobalMethaneAssessmentassessedthemethanemitigationpotentialandcostestimatesproducedbyseveralteams.Thisassessmentincludedsector-specificassumptionsabouttechnologyturnovertimes,estimatesforimprovementsintechnologyovertimeandtheachievablepaceofregulations.Costsincludeestimatesforthefuturevalueofrecoveredgasaswellasthediscountingoffuturereturnswithratesof4–10percent.Implementationofreadilyavailablemethane-targetedabatementmeasuresalongsidebroaderstructuralandbehaviouralmeasurescouldreducemethaneemissionsbyapproximately180Mt/yearby2030,whichisequaltonearly50percentofcurrentmethaneemissions.Implementationofreadilyavailablemethane-targetedmeasuresalone(i.e.excludingstructuralandbehaviouralmeasures)couldreduce2030methaneemissionsbyaround30percent.Thefossilfuelsectorshowsthelargestall-cost(i.e.notrestrictingtheanalysistolowornegativenetemissioncontrolcosts)absolute2030abatementpotentialinanalysesbythreeteams(Harmsenetal.2019b;UnitedStatesEnvironmentalProtectionAgency[U.S.EPA]2019;Höglund-Isakssonetal.2020).Methaneemissionsfromthissectorcouldbereducedbyapproximately75Mt/year(~2.2gigatonsofCO2equivalent(GtCO2e)/yearusingglobalwarmingpotentialover100years–GWP100)intheshort-term(2030)usingmethane-specificemissionabatementmeasuresrelativeto~130Mt/yearinprojected2030business-as-usual(BAU)emissions.Withinthesector,oilandgashasasubstantiallylargerreductionpotentialthancoalintwooftheanalysesandroughlyequalpotentialinthethirdanalysis.BasedontheGlobalMethaneAssessment,all-costoilandgasemissionmitigationpotentialis25–58Mt/yearby2030and35–95Mt/yearby2050(relativetoprojectedBAU2050emissionsof~155Mt/year).Averagedoverallmeasures,abatementcostsarequitesimilarforthecoalsubsector,butvarysubstantiallyfortheoilandgassubsector.Restrictingtheanalysistolowcost(<US$600/tCH4;<~US$20/tCO2eusingGWP100)measuresonly,~17–32Mt/yearcanbeabatedby2030intheoilandgassubsector,comparedwith~8–24Mt/yearinthecoalsubsector.Thelargestandmostcost-effectiveabatementpotentialswithinthefossilfuelsectorfor2030aretopreventallventingofassociatedgasduringoilandgasextraction(includingfrominefficientflaring),toinstallleakdetectionandrepairprogrammesfornaturalgasinfrastructureandtoutilizeventilationairmethaneoxidationtechnologyincoalmines(table6.1).Reducingmethaneemissionsfromwasteandagriculturewillbemorechallengingbutiscrucialtoachievinglowwarmingtargets.Forwaste,thethreeanalysesassessedintheGlobalMethaneAssessmenthaveverysimilar2030all-costabatementpotentialsrelativetoprojected2030BAUemissions(~28–32Mt/year;~30–35percent;~0.9GtCO2e/yearusingGWP100),butwithwidelyvaryingcostestimates(+US$3to-US$200/tCO2eusingGWP100).Thelargestandmostcost-effectiveabatementinthewastesectorcomesfrommunicipalsolidwaste,typicallyeitherbydivertingorganicwastefromthewastestreamorcapturingandutilizinglandfillgas.Moresimply,coveringlandfillswithsoilisaveryeffectiveandlow-costmeasure,andreducesfires,odoursandairpollution.Thiscouldbeanattractiveoptionformanytropicalandsubtropicalmegacities,whichtypicallyhaveextremelylargeandill-managedlandfills.Cropwastefiresarewidespreadinthetropics,leadingtosignificantairpollutionandmethaneemissionsfrompartialcombustion.Suchcropwastecouldinsteadbeburnedundercontrolledconditionstogenerateelectricityorreturnedtothesoiltoprovidenutrients.All-costabatementestimatesforricecultivationhavesimilarabatementpotentials(~7–10Mt/year)butvarymarkedlyincosts(roughlyUS$3–100/tCO2eusingGWP100),whereaslow-costabatementpotentialsandcostsarequitesimilaracrossanalyses.Abatementwithinricecultivationispossiblethroughchangesinagriculturalproductiontechniques,suchasalternatewettinganddryingofpaddyfields,thoughthebenefitscanbeunderminedbyincreasedN2Oemissions(table6.1).Incontrast,all-costabatementpotentialestimatesforthelivestocksectorhavesimilarcosts(~US$13–30/tCO2eusingGWP100)butsignificantlyvariedabatementpotentials(4to>40Mt/year).Thesedifferencesarelargelyattributabletoassumptionsaboutthefeasibilityofsomecountriesbeingabletoswitchtohigher-yieldinglivestockbreeds.Theaverageabatementpotentialisthereforesmallestintheagriculturesectorat~20–25percent.Severallesswell-establishedabatementoptionsarealsounderstudyforthelivestocksector,includingfeedsubstitutesandmethaneinhibitors(UNEPandCCAC2020;Ockoetal.2021).Atthesametime,substantialmitigationoflivestock-relatedmethanecouldbeachievedthroughwidespreadchangesinhumandietarychoices,possiblyreaching30Mt/year(~0.9GtCO2e/yearusingGWP100)by2050,withadditionalCO2andN2Oreductions(Willettetal.2019;UNEPandCCAC2021).50EmissionsGapReport2021:TheHeatIsOnFor2050,abatementpotentialstendtoincreasemoderatelycomparedwith2030,withtheexceptionofwasteandoilandgasinoneanalysisthatshowsverylargeabatementincreases.Theaverageabatementpotentialforwasteacrossthethreeestimatesroughlydoublesbetween2030and2050.Similarly,theaverageall-costabatementpotentialinoilandgasincreasesto~80percentofthe2050value,withroughlyhalfoftheseemissioncontrolsavailableatlownetcost.Targetedabatementestimates(withoutbehaviouralchanges)increaseonlymodestlyinagriculture,whichisexpectedtobecomethemainanthropogenicsourceofemissionsinlowwarmingscenarios(e.g.Rogeljetal.2018).Abatementcostsalsochange,withsomeofthemostnoticeableshiftsbeingthatoilandgasabatementwillbecomemoreexpensiveonaverage.Changesinlivestockabatementcostsvarysignificantlyamonganalyses.Thereareadditionalopportunitiestoreducemethanebeyondmethane-targetedabatementmeasures.Theseincludefuelswitchingfromnaturalgastorenewablesinelectricitygenerationandinbuildings,andbehaviouralchangessuchasreducedconsumptionofcattle-basedfoodsandreducedfoodwasteandloss.Integratedassessmentmodelsshowlargerangesinpotentialmethanemitigationduetotheseprocesses.Onaverage,thesemodelsindicatethatsuchactionscouldreducemethaneemissionsbyanother15percentbeyondthetargetedmeasures,foratotal2030reductionunder1.5°Cscenariosof45percentrelativetoBAU(UNEPandCCAC2021).BoththeGlobalMethaneAssessmentandOckoetal.(2021)emphasizethatfastmethaneaction,asopposedtoslowerordelayedaction,cancontributegreatlytoreducingmidterm(2050)temperatures,i.e.peakwarmingiflong-livedGHGemissionsarealsocontrolled.Fastactiontoreducemethanetoatrajectoryconsistentwith1.5°Cscenarioswasfoundtobeabletoreduceboth2050and2100globalmeantemperatures,by0.2–0.4°Cand0.4–0.8°C,respectively,comparedwithabroadsetofpotentialbaselinescenarios(UNEPandCCAC2021).51EmissionsGapReport2021:TheHeatIsOnTable6.1.Globalannualabatementpotentialin2030and2050(MtCH4andMtCO2e)SectorTechnicalabatementmeasure2030MtCH42030MtCO2e2050MtCH42050MtCO2eLivestockManureanaerobicdigestionwithbiogasrecoveryonlargefarms>100livestockunits1.2352.677Breedingforimprovedproductivity,longevityandreproduction1.23612.2354Feedmanagementandfeedadditives1.8549.5274RicecultivationImprovedwatermanagement,useofalternativehybridsandsoilamendments6.11773.9112BurningofagriculturalwasteresidualsBanandenforcementofbans1.8523.189CoalminingPre-miningdegasification4.412817.7513Ventilationairmethaneoxidation6.017316.8488Floodingofabandonedcoalmines1.7508.0231OilproductionIncreasedrecoveryofassociatedpetroleumgas14.842912.6366Leakdetectionandrepairprogrammes4.713617.5507GasproductionLeakdetectionandrepairprogrammes9.427414.4416GastransmissionpipelinesLeakdetectionandrepairprogrammes2.77910.6308GasdistributionnetworksReplacementofgreycastironpipesandleakdetectionandrepair6.719518.0522FoodindustrywasteAnaerobicdigestionwithbiogasrecovery3.29321.3617Paper,textileandwoodindustrywasteRecyclingandincinerationwithenergyrecovery1.8535.1147MunicipalsolidwasteSourceseparationandanaerobicdigestionwithbiogasrecovery6.117711.8341Sourceseparationandrecycling5.917014.1410Sourceseparationandincinerationwithenergyrecovery3.710913.3385Wastewater–industryTwo-stageanaerobicandaerobictreatmentwithbiogasrecovery6.719523.1671Wastewater–municipalUpgradeofprimarytosecondary/tertiarywithbiogasrecovery1.2355.8169Allsectors912,6502417,000Source:Höglund-Isakssonetal.(2020)52EmissionsGapReport2021:TheHeatIsOn6.4Linkbetweenmethanemitigationandpathstonet-zeroCO2Thereareimportantlinksbetweenmethaneemissionsandthepathtonet-zeroCO2.Scenarioswithstrongclimatechangemitigationpoliciesincludedecarbonizingtheeconomy,whichwouldreducemethaneleakagefromfossilfuelsystemsduetoreduceddemand.However,decarbonizationwillleadtomoreabandonedoilandgaswellsandcoalmines,whichwouldneedtargetedactionstoreducemethaneemissionsthataredistinctfromdirectdecarbonizationpolicies(e.g.Kholodetal.2020).By2050,methaneabatementassociatedwithdecarbonizationaloneisonlyabout30percentofthemethaneabatementseenunderabroadmulti-pollutant,multi-policy2°Cscenario,emphasizingthelargeroleplayedbymethane-specificpolicies.Onamorefundamentalphysicallevel,thelessmethaneisreduced,thesmallertheavailablecarbonbudgetwillbethatisconsistentwithagiventarget(e.g.Rogeljetal.2018).Quantitatively,every~100Mtofmethaneemissionsreducedandkeptreducedincreasesthecumulativetwenty-firstcenturycarbonbudgetbyaround450GtCO2.Therearealsomanylinkagesbetweenmethanereductionactionsandopportunitiesfordecarbonization.Forexample,withinlanduse,theabatementoflivestock-relatedmethanetypicallyinvolvesreduceddemandforcattle,whichthenfreesuppastureandfeedlandsforpotentialproductionofbiofuelsorafforestation.Methane-formedsurfaceozoneisknowntoreducethegrowthrateofmanyplants,affectingbothcrops(andthereforelanduse,asagreaterareawouldberequiredtoproducethesameyield)anddecreasingCO2uptakebyforests(e.g.Sitchetal.2007).Finally,usingorganicmaterialfromlandfillsasplasticsubstitutescouldreducetheneedforpetroleum-basedplastics,whichcouldplayaroleinthetransitionawayfromfossilfuels(thoughlikelyamodestrole),whilereducinglandfill-relatedmethaneemissions.Asshown,severalmethanemitigationpathwaysalsohavethepotentialtocontributetoCO2mitigation.6.5MethanemitigationinthefirstNDCsManycountriespresenttheirmitigationpledgesforGHGemissionreductionsinvariouswaysintheirNDCs.2Someemissionstargetsarenotquantitative,whilemostthatarequantitativetendtobeprovidedasaggregatedGHGs,whichmakesitdifficulttodiscernprojectionsforindividualgases(atpresent,individualgasesareonlyreportedinnationalcommunicationsubmissionsbyAnnexIcountriesfortrajectoriesbasedoncurrentpolicies).Theemissionsimplicationsofmanymajoremitters’firstNDCcommitmentshavebeenanalysedaspartofalargeinternationalresearchproject.Usingasuiteofglobalandnationalmodelsand2TheassessmentinthischapteronlyconsidersthefirstroundofNDCs.NeworupdatedNDCsarenotconsidered.informedbypolicy-specificinputfromnationalexperts,theprojectdevelopedarangeofplausibleimplementationpathwaystoachievetheNDCs(Roelfsemaetal.2020).Theprojectalsoexaminedaleast-cost2°Cscenario(accountingformitigationcostsonly,andexcludingenvironmentalcosts),withreductionsstartingin2020anda66percentchanceofstayingbelow2°C.Accordingtothoseestimates,somecountrieshavemadepledgesthatwouldleadtosubstantialdecreasesintheirmethaneemissionsby2030(table6.2).Extrapolatingcountries’NDCsrevealsthatmostareprojectedtoachievesubstantiallygreaterreductionsby2050than2030.Japanistheexception,showingasmallerreductionin2050.Agroupofmajoremittingcountries,includingtheUnitedStatesofAmerica,EuropeanUnionnations,JapanandCanada,haveNDCsthatwilllikelyresultinreductionsof~80–88percentofthoseseenin2°Cleast-costpathwaysby2030comparedwith2015,and~69–77percentby2050.However,mostoftheworldisnotyetascloseto2°Cpathways,soattheglobalscale,NDCsareexpectedtodeliveronlyaboutathirdof2030methanereductionsexpectedunder2°Cscenarios.Amongthemajoremittingcountriesanalysed,China,theRussianFederation,IndiaandAustraliashowthegreatestemissiongapsformethane,withtheirNDCreductionsrelativetotheir2°Creductionslessthantheglobalmeanforboth2030and2050.Methanereductionsin1.5°Cleast-costpathwaysare44percentatthegloballevelby2030comparedwith2015,ratherthan34percentfor2°C.TheNDCsarethereforeprojectedtodeliveronlyaboutonequarterof2030reductionsin1.5°Cpathways.TheInternationalInstituteforAppliedSystemsAnalysis(IIASA)hasalsocarriedoutanalysesoftheimpactofNDCsonmethanefortheEuropeanUnion,whichshowdecreasesof21percentby2030and34percentby2050(relativeto2015),resultsthatareverysimilartothoseshownintable6.2.53EmissionsGapReport2021:TheHeatIsOnTable6.2.Projectedchangesinmethaneemissionsrelativeto2015undernationallydeterminedcontributionsandundera2°Cscenario203020302030203020302030Country%decreaseinNDC%decreasein2°CNDC/2°CfractionCountry%decreaseinNDC%decreasein2°CNDC/2°CfractionRepublicofKorea262989USA445777USA303488EU375074Canada445187Japan395571Japan465486Canada507269EU222880Indonesia406561Indonesia234059Brazil213856Turkey223858RepublicofKorea316449Brazil112348Turkey265944Global113434Global235541Restofworld103430Restofworld225739Australia2918China185930RussianFederation53516RussianFederation196330China64015India84617India1263Australia54312Note:ProjectionsforboththeNDCsandthe2°CscenarioarebasedonRoelfsemaetal.(2020)andPBLNetherlandsEnvironmentalAssessmentAgency(undated).Althoughrangesacrossthemodelswerenotspecifiedformethanealone,thetenthtoninetiethpercentilerangeoftheemissionsgapbetweentheNDCsand2°CscenarioforallGHGswas~36percentatthegloballeveland30–55percentatthenationallevel,indicatingthatasimilaruncertaintyrangeisappropriateformethaneestimates.TheassumptionsandunderlyingdataaredescribedinRoelfsemaetal.(2020).Althoughtherearesignsthattransformationistakingplaceinsomepartsoftheworld,moreambitiouseffortsareclearlyneedediftheworldistoaimfor2°Cor1.5°Cpathways.Incountriesorregionswithlargeprojecteddecreasesinmethaneemissions,specificpolicieshavebeenputintoplacetoachievesuchreductions.Examplesincludethe2016NorthAmericanLeaders’Summitagreementtoreduceoilandgasmethaneemissionsby40–45percentby2025(relativeto2012)inCanada,MexicoandtheUnitedStatesofAmerica,theEuropeanUnion’s2020strategytoreducemethaneemissions(COM/2020/663final)andthegoalsofNigeriaandCôted'Ivoiretoreduceoilandgasmethaneemissionsby60–75percentby2030aspartoftheUNEPandCCACGlobalMethaneAlliance.InSeptember2021,theUnitedStatesofAmericaandtheEuropeanUnionannouncedaGlobalMethanePledgetoreduceanthropogenicmethaneemissionsbyatleast30percentgloballyrelativeto2020levelsby2030.On11October2021,theyreportedthatmorethan30additionalcountrieshadcommittedtojoiningthePledge,withcoveragenowincludingnineofthetop20methaneemittersglobally,andurgedotherstosignonbeforetheofficiallaunchatthetwenty-sixthUnitedNationsClimateChangeConferenceoftheParties(COP26).Thereisaclearneedforincreasedambitionalmosteverywhere,withpossibleactionsthatpolicymakerscouldconsiderincludingincreasedeffortstobuildongrowingmomentumtomonitorandaddressenvironmentalimpactswithintheprivateinvestmentcommunity.Moretransparentdataonsector-specific‘bestpractice’methaneemissionswouldhelpsupportamarketforbothmonitoringandmitigationservicesbyfacilitatingtheidentificationofthebest-performingcompanies.54EmissionsGapReport2021:TheHeatIsOnNDCstypicallyincludemoreinformationabouttheenergysectorthantheagricultureorwastesectors.EverycountryemitsGHGsfrommunicipalwaste,whichislargelygeneratedbythehumanpopulation(Eggelstonetal.2006).InNDCsrepresenting174countries,137includedgeneralwastesectormitigationcommitments,with67citingspecificmitigationactions(Powelletal.2018).Themostcommonmitigationactionwasimprovedlandfilling,followedbyconvertingwasteintoenergy(e.g.incinerationandconversionoflandfillgasintoenergy).Improvementsinwastemanagementsystemscouldprovidepublichealthco-benefits,suchasreducinghazardsassociatedwithwastewatermismanagement,improvingairqualityanddiminishinglandandwatercontamination(Mittaletal.2017;Cohenetal.2021).Agriculturalmethaneemissionsprimarilyderivefromanimalstocksandricecultivation,aswellasdeliberatebiomassburning,factorsthatvarywidelyfromcountrytocountry(FoodandAgricultureOrganizationoftheUnitedNations[FAO]2021).IntheirfirstNDCs,32countriesreferredto‘climate-smartagriculture’,withaimstooptimizeagriculturalsystemstoincreaseproductivityandincomes,enhanceresilienceandreduceGHGemissions(Strohmaieretal.2016).However,countriesrarelyincludedquantitativetargetsforreducingagriculturalmethaneemissions(Hönleetal.2019).Infact,ofthetop46countriesthatcontributeto90percentofglobalagriculturalemissions,onlyaquarterincludedbroadly-statedmeasurestargetingemissionsfromruminantlivestock.Thismaybeduetorelativelyhighabatementcostsandtheimpactsuchmeasuresmayhaveoneconomicallyimportantsectorssuchasbeefanddairy.Mitigationmeasuressuchassustainableintensificationofricecultivationweremorelikelytobeincluded,inpartbecausetheypresentclearco-benefitsformodernizationorproductivity(Hönleetal.2019).Themagnitudeofagriculturalmethaneemissionssuggeststhatagricultureshouldreceivemoreattentionthanitcurrentlydoesinmethanemitigationstrategies,andthatstrategiesthatincludechangesinconsumptionthroughafoodsystemsapproachwillneedtobeconsidered(Tubielloetal.2021).Settingquantitativegoalsforcroplandandlivestockmanagement,whichcouldcomeintheformoftargetsforbestpractices,wouldhelpcountriesraisetheirambitioninthissector.6.6Measurement-basedverificationofuncertainemissionreportingInmanycases,methanemitigationeffortsarehamperedbyuncertaintiesrelatingtoactualemissionnumbers,makingitimportanttourgentlyimproveapproachesformeasuringandreportingemissions.Improvedmonitoringatthefacilitylevelcouldservetomotivateactiontoreduceemissionsandtoverifytheeffectivenessofsuchaction.Thiswouldopenupopportunitiesforregulatorstouseflexiblepolicyinstrumentsthatdirectlytargetmeasurableemissionreductionscomparedwithmoreprescriptivebestavailabletechnologystandards.Effectivelyprioritizingmethanesources,reducingmethaneemissionsandtrackingmitigationprogressnecessitatesabroadsuiteofmeasurement-basedtechnologiesthatdrawontheuniqueadvantagesofeach.Traditionalbottom-upapproaches,basedonsource-specificemissionfactorscombinedwithstatisticalactivitydata(forexample,livestocknumbers,amountofoilandgasextracted),haveinherentuncertaintiesthatcanbelargeatthenational/sectoralscale(figure6.1),especiallyfornon-Annex1countrieswithlimitedinstitutionalcapacityanddataavailability(Solazzoetal.2021).EvenincountriessuchasGermanyandtheUnitedKingdom,whichhavewell-establishedemissionreportingsystems,methaneinventorieshavebeenrevisedbyupto60percentbetweensubsequentsubmissions(Bergamaschietal.2010).Newtop-downapproacheshavebeendevelopedthatuseatmosphericobservations(atthesurface,airborneorfromsatellites),whichwhencombinedwithatmospherictransportmodels,canbeappliedtodetermineemissionsforaspecificfacility,sector,regionorotheraggregation.Thesetop-downapproacheshaveproveneffectiveincorrectingemissionfactorsandinrevisingsectoralmethaneemissionsinmultiplegeographies(e.g.Alvarezetal.2018;Zavala-Araizaetal.2021),andinthiswayhaveprovidedopportunitiesforidentifyingspecificsourcesandmitigationopportunities(Lyonetal.2016;Johnsonetal.2017).Top-downapproachescanalsosupportthetransparencyofreportingprocesses,withtheupdatedIPCCreportingguidelinesrecommendingtheapplicationofsuchapproachesasadditionalqualitycontrol(Bartrametal.2019).However,atpresent,onlySwitzerlandandtheUnitedKingdomincludetop-downmethaneestimatesinanannextotheirnationalinventoryreports(Manningetal.2011;Henneetal.2016).Newobservationalcapabilitiesarerevealingemissionhotspotsandfacility-orcity-scaleemissionsthroughmeasurementsfromcars,dronesandaircraft,andsatelliteremotesensing,especiallyinremoteworldregions,whichinatleastafewcaseshasledtoindustryactiontoeliminatemajoremissionpointsources(Nisbetetal.2020).However,atalargerscale,top-downmethodsdependhighlyonthedensityofobservationsandarechallengedbythedifficultyindisentanglingdifferentsourcesandseparatingnaturalemissionsfromanthropogenicemissions,whichiscrucialformanycountrieswithlargenaturalemissions.Comparedwithhigh-frequencyinsitusurfacemeasurements,satelliteobservationshaveabroadercoveragebutlesssensitivitytomethanesources,andarelimitedbycloudcoverage.Furtherdeploymentofmobilemeasurementsandfixedstationsshouldthereforebesupportedtobettermonitormethaneconcentrations,especiallyovertropicalandborealregions.55EmissionsGapReport2021:TheHeatIsOnInthenearfuture,wideruseoftop-downapproacheswillbefacilitatedbyanewInternationalMethaneEmissionsObservatory(IMEO)hostedbyUNEP.TheInternationalEnergyAgency(IEA)MethaneTracker(2020)alreadyincludesdataonleakedmethaneofsuperemitters,whichisdetectedbytheTROPOsphericMonitoringInstrument(TROPOMI),withanewgenerationofsatellites,suchasGHGSat(Varonetal.2020),beingspecificallydesignedtomapandquantifypointsources.56EmissionsGapReport2021:TheHeatIsOnTheroleofmarketmechanismsinbridgingtheemissionsgapLeadauthors:ShaYu(PacificNorthwestNationalLaboratory[PNNL],USA),MaoshengDuan(TsinghuaUniversity,China),JaeEdmonds(PNNL,USA)Contributingauthors:KatherineCalvin(PNNL,USA),StefanoDeClara(InternationalCarbonActionPartnership[ICAP],Germany),DirkForrister(InternationalEmissionsTradingAssociation[IETA],Switzerland),StephanieLaHozTheuer(adelphi,Germany),LucaLoRe(InternationalEnergyAgency[IEA],France),RubenLubowski(EnvironmentalDefenseFund[EDF],USA),AxelMichaelowa(PerspectivesandUniversityofZurich,Switzerland),ClaytonMunnings(UniversityofCalifornia,Berkeley,USA),KarenHolmOlsen(UNEPDTUPartnership,Denmark),MandyRambharos(Eskom,SouthAfrica),ChandraShekharSinha(WorldBank,USA),DetlefvanVuuren(PBLNetherlandsEnvironmentalAssessmentAgency,theNetherlands)77.1.Introduction:TheroleofcarbonmarketsandcurrentstatusIntheParisAgreement,cooperationamongcountriesisconsideredawaytobothimplementnationallydeterminedcontributions(NDCs)andpromotegreaterambition,whilealsofosteringsustainabledevelopmentandencouragingbroadparticipationfromtheprivateandpublicsectors.Marketmechanismsarethereforeseenasanimportantcomponentincollectiveactiontoachievethelong-termgoalsoftheParisAgreement.Inprinciple,theroleofmarketswithinthecontextoftheagreementistoenableallpartiesengagedinmitigationactionstoimplementtheseinacost-effectivemanner,whilesimultaneouslyprovidinganopportunitytoenhancetheirambition.Underarticle6,theParisAgreementprovidesforaninternationalframeworkformarketmechanismstoenablegreaterambitioninbothmitigationandadaptationactions(Bodanskyetal.2016).ItalsoallowscountriestovoluntarilycooperatetoachievetheirNDCs,“promotesustainabledevelopmentandensureenvironmentalintegrityandtransparency”(article6.2),solongaspartiesavoiddoublecountingmitigationoutcomes.Thefactthat87percentofnewandupdatedNDCsspecifycountries’intentionstopossiblyusevoluntarycooperationunderarticle6(UnitedNationsFrameworkConventiononClimateChange[UNFCCC]2021)confirmsasignificantlyincreasedinterestinthisapproach,comparedwithpreviousNDCs.Althougharticle6establishedtheseprinciples,therulesthatfacilitatetheirimplementationinpracticearestillthesubjectofnegotiations,includingguidanceforcooperativeapproaches(article6.2),whichcoversallformsofinternationalmitigationmarkets,therulesforamechanism(article6.4),andaframeworkandworkprogrammetopromotenon-marketcooperation(articles6.8and6.9).Theserules,modalitiesandproceduresareananticipatedkeyoutcomeoftheoftwenty-sixthUnitedNationsClimateChangeConferenceoftheParties(COP26).Thereisalreadyconsiderableexperienceindesigningandimplementingmarketmechanismstocontrolpollutants,includingdifferentformsofcarbonmarkets(SchmalenseeandStavins2017;Michaelowaetal.2019a;WorldBank2021a).Thecurrentstateofcarbonmarketsisverydiverse.Suchmarketsincludebothvoluntaryandcompliance-drivenprogrammes,whichareusedbothdomesticallyandinternationallytoreduceemissions,andinvolvedifferenttypesofallowancesandcreditsandbothpublicandprivatesectorentitiesasbuyersandsellers(box1,figure7.1).57EmissionsGapReport2021:TheHeatIsOnBox7.1.CurrentstateofcarbonmarketsCompliancecarbonmarketsaremarketplacesinwhichparticipantsactinresponsetoanobligationestablishedbyaregulatorybody.Themostprominentexamplesofsuchmarketsarenationalorregionalemissionstradingsystems.Innationalemissionstradingsystems,governmentssetacapontheaggregatelevelofgreenhousegas(GHG)emissionsthatregulatedentitiescanemitoveraperiodoftime.Theseentitiesarerequiredtosubmitanemissionpermit(orallowance)foreachtonofcarbondioxideequivalent(tCO2e)theyemit.Emissionstradingsystemscanberestrictedtodomesticbordersormayhaveinternationalelementsthroughlinkswithotheremissionstradingsystems(e.g.theEuropeanUnion,theEuropeanUnion-SwisslinkandtheCalifornia-Quebeclink)and/ortheacceptanceofinternationaloffsets(e.g.theRepublicofKorea’sEmissionsTradingScheme–K-ETS).Involuntarycarbonmarkets,participantsareundernoformalobligationtoachieveaspecifictarget.Instead,companies,privateentitiesandnationalgovernmentsseektovoluntarilyoffsettheiremissions,forexample,aspartofasocialresponsibilitystrategy.Voluntarybuyerscanprocuredomesticorinternationalcarboncreditsfromvariousdifferentcreditingprogrammes,aswellasallowancesfromcompliancemarkets(Dodaetal.2021).Compliancecarbonmarketshavehistoricallygeneratedmoremitigationactionandstrongerincentivesfordecarbonizationthanvoluntarycarbonmarkets,thoughtheymayfacemorepoliticaloppositionandentailhigherregulatoryburdens.Voluntarycarbonmarketscanbeanimportanttooltomobilizetheprivatesectorandexpandthereachofcarbonmarketsbeyondsectorsandregionssubjecttoexplicitclimateregulation.Intermsofstructure,domesticcarbonmarketshavetheadvantageofnormallyallowingbetteroversightandcontrolthroughfullregulatorycontrolbyarelevantauthority,withlittleriskofspillovereffectsfromothersystemsorjurisdictions,andallmitigationbenefitsaccrueddomestically.Addinginternationalelementstomarketswillincreasetheircomplexity,butalsopresentsasignificantadvantageofpotentiallyreducingcompliancecostsbymakinguseofcheapermitigationopportunitiesinotherjurisdictions.Figure7.1aMarkettypologyDomesticComplianceVoluntaryInternationalDomesticcarbonmarketsGovernmentcompliancewithinternationalcountrytargets(UNFCCC)Figure7.1aMarkettypologyPrivateentitiesGovernmentsInternationallylinkedETSsAviationoffsetting(CORSIA)DomesticcarbonmarketswithintloffsetsCorporateandpersonalcarbonfootprintoffsettingGovernmentvoluntaryoffsettingSource:AdaptedfromLaHozTheuer(2021)58EmissionsGapReport2021:TheHeatIsOnFigure7.1bCross-borderunittransfersFigure7.1bCross-borderunittransfersPrivateentitiesPublic/PrivateGovernmentsSellersAssetAssetoversightframeworkBuyersGovernmentsCarboncreditsAllowancesOverachievementofNDCsParisAgreementarticles6and13Creditingprograms:•UN-operated•Government-operated•IndependentCompliancebuyers(countries,companies,airlines)EmissionstradingsystemsPrivateentitiesVoluntarybuyers(companies,individuals,governments)Source:AdaptedfromLaHozTheuer(2021)Experiencesfromthesevariousmarketsandapproachesprovideimportantlearningsforthedesignofnewcooperativeapproaches.ThischapterinitiallyprovidesanassessmentofthepotentialroleofmarketmechanismsundertheParisAgreementinboththeneartermandinachievinglong-termclimategoals(section7.2),thenexaminestechnicalissuesthathaveimplicationsfortheeffectiveimplementationofarticle6(section7.3),andfinallydiscussesactionsthatcanbetakentounlockmarketpotentialsandenhanceambition(section7.4).7.2.ThepotentialroleofinternationalcarbonmarketsundertheParisAgreement:near-termversusnet-zeroimplications7.2.1.Near-termimplicationsNDCsdefinethemitigationcontributionofeachpartytomeetingthegoalsoftheParisAgreement.CountrieshavepreparedtheirNDCsusingdifferenttargettypesandmetricsrangingfromreductionsinallgreenhousegas(GHG)emissionsrelativetoafixedemissionslevel(e.g.a50percentreductioninallGHGsin2030relativeto2005),tospecificactionssuchasplantingaspecificnumberoftreesbyaspecificdate,toconditionalcontributionsthatapplyonlyifanadditionalconditionismet(HoodandSoo2017).TheheterogenousnatureofthecurrentNDCsinthiswaycreateschallengesforbothnegotiatingandestablishingeffectivereal-worldmarkets,aswellastherisksofdoublecounting,emissionleakagesandunattainabletargets.ThereisgrowinginterestfromcountriesinusingmarketsandvoluntarycooperationtoimplementtheirNDCs.Asof30July2021,theshareofpartiesthatindicatedanintentionorpossibilityofusingvoluntarycooperationhasnearlydoubled,from44to87percentintheneworupdatedNDCs,comparedwithpreviousNDCs.Moreover,theshareofpartiesthathavesetqualitativelimitsonvoluntarycooperation,suchasusingcertainstandardsandguidelinestoensureadditionalityandavoiddoublecounting,hasincreasedfrom19to39percent(UNFCCC2021).TheexistingquantitativeliteraturethatestimatesthemaximumpotentialgainsfromcooperationgenerallyassumesthattheheterogeneousNDCscouldbetranslatedintoacommoncomprehensive,transferableemissionsmitigationmetric.Thisisevidentlynotsomethingthatisgoingtohappenquickly,ifatall,andtheresultsmustthereforebeinterpretedasestimatesofpotentialgainsfromcooperationcomparedwithindependentimplementationofthesametargets.Thesestudiesdonotincludeancillarydomesticbenefitsthatmayhavemotivatedcountries’choiceofNDCtargetmethods.ArelativelylimitednumberofstudieshavesofarprovidedquantificationofthegainsfromcooperativeimplementationofNDCpledges(e.g.Fujimorietal.2016;Hofetal.2017;Edmondsetal.2019;Böhringeretal.2021;Edmondsetal.59EmissionsGapReport2021:TheHeatIsOn2021).WiththeaimofachievingthecurrentNDCambitionthroughglobalcooperation,mostmodelsestimateaglobalcarbonpriceofUS$9–38/tCO2between2025and2030.1Incontrast,thestudiesfindthatduetothevaryingstringencyinNDCs,theshadowpriceofcarbonforacountrytoindependentlyandcost-effectivelyachieveitsunconditionalNDCpledgeby2030rangesfromUS$0/tCO2tooverUS$250/tCO2acrossmodelsandstudies(witheachstudyanalysingthen-currentNDCpledges),highlightingthepotentialgainsthroughinternationalemissionstrading.Asaresult,theestimatedmitigationcostsby2030inanidealsituationcouldbereducedby40–60percentthroughthefulluseofmarketmechanisms(Aldyetal.2016;Fujimorietal.2016;Hofetal.2017;Edmondsetal.2019;Edmondsetal.2021).Althoughthereareuncertaintiesassociatedwitheconomicmodelling,resultsinallstudiessuggestsignificantpotentialcostreductionsandeconomicgainsfromusingmarketmechanisms.Theseresultsprovideastrongincentiveforcountriestonegotiateacredibleagreementonarticle6andtomovetowardsmorecompatibleNDCsovertime.Themodellingstudiesestimatethataround4–5GtCO2ecouldbetradedperyearby2030withamarketvolumeofUS$60–100billionperyearifNDCsaretransformedintotradableemissionmitigationactions(Fujimorietal.2016;Edmondsetal.2019;Edmondsetal.2021).Netmarkettransactionsconstitutebalance-of-tradechangesandthereforechangestoparticipants’grossdomesticproduct(GDP)and/orexchangerateposition.Forsellingregions,thiswouldrepresentapotentiallysignificantnewnetexport(Piris-Cabezasetal.2019;Edmondsetal.2021;Kachietal.2020).Theextenttowhichthiswillactuallyoccurisveryuncertain,withmanypartiesemphasizingdomesticimplementationandmentioningflexiblemechanismsasanadditionalityintheirNDCs.Carbonmarketsshiftbothemissionmitigationactionsandemissionmitigationinvestmentsfrombuyerstosellers.Providedthatsellersareprimarilydevelopingcountries,carbonmarketshavethepotentialtotransferemissionmitigation-relatedcapitaltowardsdevelopingeconomies,helppreventlock-instocarbon-intensiveinfrastructureandcontributetocapacity-buildingtofurtherreduceemissions.Redistributingcapitalinvestmentspotentiallycarriesimplicationsforothersustainabilitymetrics,suchaslocalairquality,forestconservation,rurallivelihoods,foodprices,waterqualityandenergyaccess,aswellasfortheregionaldistributionofincentivesfortechnologydevelopmentandinnovation.Whileincreasingemissionmitigationinnovationsinsellingregions,carbonmarketscouldreduceincentivesinbuyingregions.Inbuyingregionswithgreatercapacityto1TheAsia-PacificIntegratedModel/ComputableGeneralEquilibrium(AIM/CGE)2.0ADVANCEDanalysisfromtheIntergovernmentalPanelonClimateChange(IPCC)SpecialReportonglobalwarmingof1.5°Cdatabaseestimatesasubstantiallyhighervalueofcarbonprice(US$73/tCO2)by2030.developcapital-intensiveemissionmitigationtechnologies,theoverallpaceoftechnologicalchangethatfavoursemissionsmitigationcouldbereducedifambitionsarenotincreasedatthesametime.However,underdifferentpolicydesigns,near-termflexibilityfacilitatedbylow-costmitigationoptions,suchasreducingtropicaldevastation,canfreeresourcestoboostinvestmentsintoresearchanddevelopmentandyieldimprovedtechnologiesinthelongerterm(Szolgayová,GolubandFuss2014;Kochetal.2017).Studiesofpotentialemissionsmitigationwithinternationalmarketsindicatethatland-useemissionmitigationopportunitiesareundertakenearlierthanunderindependentNDCimplementation(Edmondsetal.2021).Byvaluingland-usechangeemissions,internationalcarbonmarketscanalsoprovideincentivestopreventdeforestationandincreaseafforestationandreforestation(LubowskiandRose2013;Fujimorietal.2016;Edmondsetal.2019;Piris-Cabezasetal.2019;Edmondsetal.2021;Fuss,LubowskiandGulub2021).TheneedforaninterlinkedimplementationofclimategoalsandtheSustainableDevelopmentGoals(SDGs)isbeingincreasinglyrecognizedatthepoliticalleveltoenhancesynergiesandmaximizeco-benefits.However,toolsandapproachestoassessandreportonsustainabledevelopmentimpactsofarticle6cooperativeapproachesarelackingandremainanunresolvedtopicinnegotiations(Olsen,ArensandMersmann2018;KachiandMooldijk2020).Similarly,thereareunresolvedissuesabouthowtheuseofcooperativeapproachescanbedesignedtocontributetofinancingadaptationinvulnerablecountrieswithlimitedpotentialfordirectparticipation.7.2.2.Net-zeroimplicationsForclimatechangetostabilize,globalanthropogenicnetemissionsmustdeclinetozero(chapter3).Asof13September2021,50partiestotheUnitedNationsFrameworkConventiononClimateChange(UNFCCC)haveannouncednet-zerotargets,ofwhichfivepartieshaveexplicitlyindicatedtheirintenttouseinternationaltradingtoachievetheirnet-zeropledges.Inaddition,agrowingnumberofnon-Stateandsubnationalactorshavemadenet-zeropledgeswithtradingconsidered.Whenglobalnetcarbonemissionsstarttoapproachzero,carbonmarketconditionswillbeverydifferenttohowtheyarecurrently.Reducingglobalcarbonemissionstonetzeroinvolvesreducingcarbonemissionstonearzeroinallsectorsinallregions,withemissionsthatremainpositivebeingoffsetbyso-callednegativeemissionsorcarbondioxide(CO2)removal(seechapter3).Thissuggeststhattheoverallscopefortransactionsinphysical(i.e.tonsofCO2–tCO2)willshifttowardsnegativeemissionsovertime.60EmissionsGapReport2021:TheHeatIsOnThemarginalcostofremovingthefinaltonsofCO2fromsomehard-to-abatesectorsandregionscouldbecomehigh,implyingthattransactionsthatoccurcouldbeveryvaluable.Asdiscussedinchapter3,net-zeropledgesacrosscountriesandorganizationshavedifferenttimings,sectoralcoverage,gascoverageandlegalstatuses.Inadditiontothechallengesdiscussedinsection5.3,ambiguityofnet-zerotargetscreatesadditionalbarrierstousingmarketmechanismstoachievenet-zerotargets.FurthercomplexityarisesfromuncertaintyinhowtotreatthevariousformsofCO2removal(NationalAcademiesofSciences,Engineering,andMedicine2019)incarbonmarkets.Somecarbonmarkets(Australia,Colombia,NewZealandandtheRepublicofKorea,andCalifornia,AlbertaandChina’sregionalsystems)alreadyrecognizetheroleofnature-basedremovalcreditsandthelong-termimportanceofbringingemissionsourcesandsinksintoacommonmarketframeworkaimedatachievingnet-zeroemissions(LaHozTheueretal.2021).Toreachglobalnet-zeroemissions,countrieswithemissionsgreaterthanzeromayneedtobebalancedbycountrieswithnegativeemissions.Almostallglobalnet-zeroscenariosassessedintheIntergovernmentalPanelonClimateChange(IPCC)SpecialReportonglobalwarmingof1.5°CandFifthAssessmentReportdatabaseshavesimilarmarginalcostsacrossworldregions,whichimplicitlyassumeinternationalcooperationtoachieveglobalnet-zeroscenarios.VanSoestetal.(2021)examinedcost-optimalemissionphase-outyears,withoutfairnessconsiderations,forboth1.5°Cand2°Ctargetsacrosssixintegratedassessmentmodels.Theirfindingsrevealedsignificantvariationsinthetiminginwhichcountriesreachednet-zeroemissions,whichindicatesthatthereispotentialforusingmarketmechanismstoachieveaglobalnet-zerogoal.Themagnitude,valueandpatternsofemissionstradingtoreachaglobalnet-zerotargetaredynamicanddependonseveralfactors,suchastheuseofCO2removaltechnologiesandthetimingofreachingnetzeroineachregion(Yuetal.2021).Marketsize,forexample,reachesUS$300–400billionin2030andaroundUS$1trillionin2050inscenarioswithdifferentnet-zerotimings.Studieshavefoundthatlandresourcesalsoplayanimportantrole(IntergovernmentalPanelonClimateChange[IPCC]2018;Yuetal.2021).Removalcreditsbytechnology-basedCO2removalapproachescouldplayanincreasinglyimportantroletoachievenet-zeroemissionsbutwillbelimitedbytheglobalremovalcapacityofthesetechnologies(Allenetal.2020;LaHozTheueretal.2021).Box7.2.EnhancingambitionthroughcarbonmarketsThemaingoalofarticle6oftheParisAgreementistoenablepartiestoincreasetheirambitiontowardsachievingtheagreement’slong-termgoals.Manyresearchershavedocumentedthattheinitialnationallydeterminedcontributions(NDCs)areinsufficienttobealignedwithtrajectoriestoreachthelong-termParisAgreementgoals(Fawcettetal.2015;UnitedNationsEnvironmentProgramme[UNEP]2020).However,recentstudiesbyPiris-Cabezasetal.(2019)andEdmondsetal.(2021)haveshownthatifthesavingsfrommorecost-effectiveglobalimplementationofNDCswereredeployedtowardsincreasedambition,globalemissionreductionscouldberoughlydoubledoverthenextdecadeatnoaddedcosttopartiescomparedwithpartiesactingalonetoimplementtheircommitments(figure7.2).Amajorpartofthepotentialambitionincreasesderivesfromnaturalclimatesolutions,notablyforests.Piris-Cabezasetal.(2019)estimatethatthisdoublingofclimateambitionprovidesabouttwothirdsofthereductionsnecessarytogetona2°Cpathwaythrough2035,closingabouthalfofthecurrentgapwithoutanyaddedcostcomparedwithpartiesactingindependently.Althoughthesecalculationsareevidentlyspeculative,theyhighlightboththepotentialpowerofcarbonmarketsandhowfarNDCsneedtobeenhancedtocapturethatpotential.Carbonmarketsdonotcreateambitionforparties.Rather,theycreateconditionsthatmakeenhancedambitionsmoreattractivethroughtheimplicitincentivethatemissionsmitigationiscost-effective,therebyloweringpoliticalandstakeholderresistancetotighteningtargetsandfacilitatingemissionreductionsandstrengthenedtargetsovertime.Experiencefromtheworld’scurrentmajoremissionstradingsystemssupportsthisapproach(Parker2019).Emissionswithintradingsystemshavealwaysfallenfasterandatalowercostthaninitiallyexpected(Haites2018).Periodsoflowpriceshavebeenfollowedbyaperiodofpolicyreassessmentandmoreambitioustargets,asseenundertheEuropeanUnionEmissionsTradingSystem(EUETS),theRegionalGreenhouseGasInitiative(RGGI)andCalifornia’scap-and-tradeprogramme.Variousexplicitmechanismshavebeenproposedtoincreaseambition.Theseinclude,forexample,taxingor‘cancelling’aportionofemissionmitigationtrades.Underafixedemissionsbudget,suchschemescouldincreaseoverallemissionsabatementinthenearterm.However,accordingtoPiris-Cabezasetal.(2019),suchanapproachappliedonapertransactionbasisfunctionsasatypeoftariffonmitigationexportsandhinderstheabilityofmarketstodelivercost-effectivemitigation.Inthelongterm,thispreventsmarketsfromloweringcostsandtherebyfromfacilitatingincreasesinambition.61EmissionsGapReport2021:TheHeatIsOnFigure7.2.Increasedambitionpotentiallyavailablefromeconomicefficiencysavingsavailablefromtheidealimplementationofarticle6203020252020201512015=10.51.5ConditionalNDCsEnhancedambitionfromarticle6CurrentpoliciesSource:AdaptedfromEdmondsetal.(2021)7.3Usingmarketmechanismsunderarticle6AlthoughthereispotentialforinternationalcarbonmarketstoreducecoststoachieveNDCgoalsandincreaseambition,suchpotentialwillremainunknownuntilimportantdetailsaredeterminedunderarticle6.Theseincludeestablishingrobustrulestoensureenvironmentalintegrity,includingtheavoidanceofdoublecounting,capacity-buildingandthemanagementofpotentialcarbonleakages.7.3.1.GettingtheaccountingrightToavoiddoublecountingthesameemissionreductions/removals,theParisAgreementrequirespartiesparticipatinginarticle6.2cooperativeapproachestoapply‘correspondingadjustments’,i.e.adjustingthebalanceoftheiremissionsorremovalscoveredbytheirNDCstoreflectinternationallytransferredmitigationoutcomes.Toensureenvironmentalintegrityunderarticle6.4,partiesarenegotiatingtheapplicationofcorrespondingadjustments,thoughtheirimplementationisbeingcomplicatedbythediversescopeandformulationoftheparties’NDCpledges(Greineretal.2019;AsianDevelopmentBank2020).PartieshavedifferentviewsonhowtodefinethescopeofNDCs,forexample,whethertodefinethemintermsofsectors,gasesand/orpoliciesandmeasures.Thereisalsodisagreementoverwhethercorrespondingadjustmentsshouldberequiredforinternationallytransferredmitigationoutcomesgeneratedoutsidethescopeofsellingcountries’NDCs.ManyNDCsonlyincludesingle-yeartargets,suchas2025or2030,whichraisesthequestionofhowtotreatnon-complianceyearswhenaccountingforinternationallytransferredmitigationoutcomes.Severalaccountingmethodshavebeenputforwardtoaddressthischallenge(Greineretal.2019;LoReandVaidyula2019;AsianDevelopmentBank2020).7.3.2.TradewhenthebasicpolicyenvironmentlacksafixedemissionslimitTargetsettingintheNDCsisstillveryheterogeneous.SomeNDCemissionmitigationtargets(Graichen,CamesandSchneider2016;VaidyulaandHood2018;Schneideretal.2019)areexpressedinnon-GHGterms,suchasenergyefficiencyandforestry,whileothersareframedasintensitytargetsand/ortargetsrelativetoprojectedbusiness-as-usual(BAU)emissions.UncertaintiesinBAUemissionprojectionsmayweakentheactualambitionofmitigationtargets(Hood,BrinerandRocha2014;Graichen,CamesandSchneider2016;HoodandSoo2017;VaidyulaandHood2018;andRochaandEllis2020).ThescopeofNDCsalsodifferintermsofsectorsandGHGs:somecoverallsectorsandallGHGs,somehavemorelimitedcoverageandothersareunclearandonlyincludeindicators,suchaspoliciesandmeasures.ThelackofafixedemissionslimitinmanyNDCsmakesaccountingcomplex.Someresearchershaverecommendedtheuseofeconomy-wideabsoluteemissiontargetsforallNDCstofacilitaterobustaccountingandreducecomplexity62EmissionsGapReport2021:TheHeatIsOn(Graichen,CamesandSchneider2016;Schneideretal.2019).Althoughthisisnotlikelytohappenanytimesoon,partiescouldberequestedtoprovideclearerandmoretransparentNDCtargetsasapotentialshort-termstep.Forthispurpose,theKatowiceClimatePackageincludesdetailedprovisionsonhowcountriesshoulddescribeorclarifythescopeoftheirNCDs.However,someprovisionsofthispackageareonlymandatoryforsecondandsubsequentNDCsorrequirecountriestoproviderelevantinformationby2024(Schneideretal.2020).ThetreatmentofmitigationoutcomesgeneratedoutsidethescopeofNDCsisanimportantissueinnegotiations.ThemainadvantagesofallowingemissionreductionsoutsidethescopeofNDCsincludethefullutilizationofmitigationpotential,reducedmitigationcosts,improveddataqualityofuncoveredsectorsandthefacilitationoftheirinclusionintofutureNDCs(Spalding-Fecher2017;Schneideretal.2020).DisadvantagesincludedisincentivestoenhancingthescopeofNDCs,alackoffairness,scrutinyandqualityassurance,anddouble-countingrisks(Spalding-Fecher2017;Howard2018;Warneckeetal.2018;Hood2019;Michaelowaetal.2019b;SchneiderandLaHozTheuer2019;Schneideretal.2020).Manyoptionshavebeenraisedtoaddresstheabovecitedconcerns,suchasapplyingcorrespondingadjustmentsregardlessofNDCscope,bringingrelevantsectorsandGHGsintothescopeofnextNDCs,imposinginternationaloversightonthequalityofNDCsandrestrictionsonthenumberofanddeadlineforachievinginternationallytransferredmitigationoutcomes,quantifyingNDCtargetsintermsofGHGemissionsandspecifyingthescopeofNDCs(Marcuetal.2017;Mizuno2017;Spalding-Fecher2017;Howard2018;Greineretal.2019;Warneckeetal.2018;SchneiderandLaHozTheuer2019;Schneideretal.2020).Careneedstobetakeninframingsuchoffsetprogrammessothatmacroscaleoutcomesdelivertheintendedaggregateemissionsmitigation.Calvinetal.(2015)showedthatwell-intentionedoffsetprogrammeshavethepotentialtoinadvertentlyloweroverallambition.Althoughsomeoftheproposedoptionsareidealintheory,theymaylackpoliticalfeasibility.Manypartieshavebeenconcernedbypotentiallimitationsonarticle6participationandthreatstothebottom-upnatureofNDCs.7.4ThewayforwardOnepossibleoutcomeofCOP26isthatinitialarticle6ruleswillbeagreedupon,withtheintentionthattheybeimprovedgraduallyovertimeandstrengthenedthroughothermarketarrangements.ThishasbeenthecaseforotherpartsoftheParisAgreement.TheCleanDevelopmentMechanism(CDM)couldbeausefulreferenceinthisregard,asdespitereceivingmanycriticisms,ithasplayedacrucialroleinfacilitatingorenhancingmanycountries’mitigationefforts.Inmanydevelopingcountries,thecapacitiesdevelopedthroughparticipationintheCDM(e.g.tomeasureandverifyemissions)havehelpedthempreparetheirinitialNDCs.Insomecountries,suchasChinaandtheRepublicofKorea,participationintheCDMprovidedvaluablelessonsandcapacitiesforestablishingdomesticcarbonmarkets.SuccessoftheParisAgreementmarketarrangementswillrequiretheestablishmentofsolidmanagerial,technicalandinstitutionalcapacity.Partiesparticipatinginarticle6.2willneedtojointlyagreeonacooperativeframeworkforemissionreductions,decidehowtoestablishdomesticmodalitiesandprocedurestocompletetheauthorization,quantification,monitoring,verificationandreportingofinternationallytransferredmitigationoutcomesandmakecorrespondingadjustmentsafterthetransferoftheseoutcomes(WorldBank2021b).Participationinthearticle6.4mechanismwillbemoredemandingforhostpartiesthantheCDM,asitwillinvolvedocumentingtransparentreductions,aswellasshowingadditionalitytotheirNDCsandsupportingsustainabledevelopment.63EmissionsGapReport2021:TheHeatIsOnReferencesUABCDEChapter1UnitedNationsandUnitedKingdom(undated).COP26goals.Availableathttps://ukcop26.org/cop26-goals/.Accessed11October2021.UnitedNationsFrameworkConventiononClimateChange(2021).NationallyDeterminedContributionsundertheParisAgreement.SynthesisReportbytheSecretariat.17September.FCCC/PA/CMA/2021/8.https://unfccc.int/sites/default/files/resource/cma2021_08_adv_1.pdf.Accessed24September2021.Chapter2Australia,DepartmentofIndustry,Science,EnergyandResources(2020).Australia’sEmissionsProjections2020.BP(2021).StatisticalReviewofWorldEnergy.London.Brazil(2020).ParisAgreement.Brazil'sNationallyDeterminedContribution(NDC).https://www4.unfccc.int/sites/ndcstaging/PublishedDocuments/Brazil%20First/Brazil%20First%20NDC%20(Updated%20submission).pdf.Canada,EnvironmentandClimateChangeCanada(2021).Canada’sGreenhouseGasandAirPollutantEmissionsProjections2020.Gatineau,Quebec.Canadell,J.G.,Monteiro,P.M.S,Costa,M.H.,CotrimdaCunha,L.,Cox,P.M.,Eloseev,A.V.etal.(2021).Globalcarbonandotherbiogeochemicalcyclesandfeedbacks.InClimateChange2021:ThePhysicalScienceBasis.ContributionofWorkingGroupItotheSixthAssessmentReportoftheIntergovernmentalPanelonClimateChange.Masson-Delmotte,P.,Zhai,V.,Pirani,A.,Connors,S.L.,Péan,C.,Berger,S.,etal.Cambridge:CambridgeUniversityPress.Chai,Q.,Feng,S.Xu,H.,Li,W.andZhong,Y.(2017).Thegapreportofglobalclimatechangemitigation,finance,andgovernanceaftertheUnitedStatesdeclareditswithdrawalfromtheParisAgreement.ChineseJournalofPopulationResourcesandEnvironment15(3),196–208.ClimateActionTracker(2021a).ClimateSummitMo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