GETTINGTONETZEROAreportledbyCalifornia-ChinaClimateInstitute(CCCI)IncollaborationwithEnergyandEnvironmentalEconomics,Inc.(E3)andLawrenceBerkeleyNationalLaboratory(LBNL)APRIL2021NETZEROREPORTAUTHORSCalifornia-ChinaClimateInstituteDr.FanDai,Dr.FredrichKahrl,Dr.JessicaGordon,JenniferPerron,YuqingZhuE3RawleyLoken,AmberMahoneLawrenceBerkeleyNationalLaboratoryNinaKhanna,Dr.NanZhou,LynnPriceSERIESOVERVIEWThisseriesexploreswaysinwhichtheUnitedStatesandChinacancoordinatetheirnear-termandmid-termeffortstoachievecarbonneutralitybyaroundthemiddleofthiscentury,basedonareviewofdeepdecarbonizationpathwaysstudiesinbothcountries.Theseriesincludesthreereports:asynthesisreportthatdevelopsaframeworkandproposesmilestonesforU.S.-Chinacoordinationoncarbonneutrality,andtwosupportingreportsthatreviewandanalyzerecentdeepdecarbonizationstudiesintheUnitedStatesandChina,respectively.ThisreportcontainstheU.S.-Chinaframeworkandmilestonesforcarbonneutrality.ABOUTTHECALIFORNIA-CHINACLIMATEINSTITUTETheCalifornia-ChinaClimateInstitutewaslaunchedinSeptember2019andisaUniversityofCalifornia-wideinitiativehousedjointlyatUCBerkeley’sSchoolofLawandtheRausserCollegeofNaturalResources.ItisChairedbyJerryBrown,formerGovernoroftheStateofCalifornia,andVice-ChairedbytheformerChairoftheCaliforniaAirResourcesBoardMaryNichols.TheInstitutealsoworkscloselywithotherUniversityofCaliforniacampuses,departmentsandleaders.Throughjointresearch,traininganddialogueinandbetweenCaliforniaandChina,thisInstituteaimstoinformpolicymakers,fostercooperationandpartnershipanddriveclimatesolutionsatalllevels.1ACKNOWLEDGMENTSThisreportispartofa“GettingtoNetZero”seriesthatlooksatpossiblepathwaysfortheU.S.andChinatoworktogetherinachievingtheircarbonneutralitytargets.ThepolicyreportsaresponsoredbytheHewlettFoundationandproducedbyapartnershipoftheCalifornia-ChinaClimateInstituteattheUniversityofCalifornia,theChinaEnergyGroupatLawrenceBerkeleyNationalLaboratory,andE3.TheauthorswouldliketothankXiliangZhangofTsinghuaUniversity,DanFarber,MaxAuffhammerandKenAlexofUCBerkeley,AlexWangoftheUCLASchoolofLaw,VanceWagneroftheEnergyFoundationChina,JimWilliamsoftheUniversityofSanFrancisco,MarkLevineandDavidFridleyoftheLawrenceBerkeleyNationalLaboratoryfortheirreview,feedbackandcontributiontothisreport.DISCLAIMERThisdocumentwaspreparedasanaccountofworksponsoredbytheUnitedStatesGovernment.Whilethisdocumentisbelievedtocontaincorrectinformation,neithertheUnitedStatesGovernmentnoranyagencythereof,norTheRegentsoftheUniversityofCalifornia,noranyoftheiremployees,makesanywarranty,expressorimplied,orassumesanylegalresponsibilityfortheaccuracy,completeness,orusefulnessofanyinformation,apparatus,product,orprocessdisclosed,orrepresentsthatitsusewouldnotinfringeprivatelyownedrights.Referencehereintoanyspecificcommercialproduct,process,orservicebyitstradename,trademark,manufacturer,orotherwise,doesnotnecessarilyconstituteorimplyitsendorsement,recommendation,orfavoringbytheUnitedStatesGovernmentoranyagencythereof,orTheRegentsoftheUniversityofCalifornia.TheviewsandopinionsofauthorsexpressedhereindonotnecessarilystateorreflectthoseoftheUnitedStatesGovernmentoranyagencythereof,orTheRegentsoftheUniversityofCalifornia.ErnestOrlandoLawrenceBerkeleyNationalLaboratoryisanequalopportunityemployer.ThisworkwassupportedbytheCalifornia-ChinaClimateInstitute,underLawrenceBerkeleyNationalLaboratoryContractNo.DE-AC02-05CH11231.CopyrightNoticeThismanuscripthasbeenauthoredbyanauthoratLawrenceBerkeleyNationalLaboratoryunderContractNo.DE-AC02-05CH11231withtheU.S.DepartmentofEnergy.TheU.S.Governmentretains,andthepublisher,byacceptingthearticleforpublication,acknowledges,thattheU.S.Governmentretainsanon-exclusive,paid-up,irrevocable,worldwidelicensetopublishorreproducethepublishedformofthismanuscript,orallowotherstodoso,forU.S.Governmentpurposes.2CONTENTSExecutivesummary41Introduction81.1ReportOverview81.2Motivation91.3DefiningCarbonNeutrality102FrameworkBuildingBlocks112.1Pillars122.2Sectors142.3TimePeriods142.4Milestones152.5PolicyFocus163ASharedFrameworkandMilestonesforCarbonNeutrality173.1KeyDifferencesbetweentheUnitedStatesandChina173.2CarbonNeutralityPillars183.3SectoralStrategies203.4Milestones203.5KeyTechnologyStrategies,PolicyFocus,andPolicyandTechnologyGaps263.6AreasforU.S.-ChinaCoordination294Conclusions325AppendixA:DocumentationofCalculations345.1GeneralCalculations345.2WindandSolarGenerationCalculations365.3IndustrialCO2IntensityCalculations366References383GETTINGTONETZEROU.S.-ChinaFrameworkandMilestonesforCarbonNeutrality“Gettingtonetzeroisthechallengeofourtime,butit’salsoahistoricopportunitytomakeourfuturebetter.Everysinglegovernment,businessandorganizationhasaparttoplay,butit’stheUnitedStatesandChinathatwilldeterminehowfarwego.Readthisreportcloselyandlet’sgettowork—together.”-California-ChinaClimateInstituteChairJerryBrownandViceChairMaryNicholsEXECUTIVESUMMARYGlobalmomentumandambitionaroundclimateactionarenowhigherthantheyhavebeensincethe1990s.TheEuropeanUnion(EU)announcedin2019thatitwouldbeclimateneutralby2050,ChinaannouncedinSeptember2020thatitwouldbecarbonneutralby2060,theUnitedStatesannounceda2050carbonneutralitytargetthroughexecutiveorderinJanuary2021,andagrowingnumberofU.S.stateshavesetmid-centurycarbonneutralitytargets,followingCalifornia’sleadin2018.NationalandsubnationalcollaborationbetweentheUnitedStatesandChinacanacceleratethismomentumandsupportachievementoflonger-termcarbonneutralitygoals.Thetwocountriesaretheworld’sdominantgreenhousegas(GHG)emitters,itslargesteconomies,andtheirbilateralrelationshipwasinstrumentaltoformationoftheParisAgreement.Collaborationcouldtakemanyforms,but,ataminimum,itrequirescoordination:transparentandsharedmilestonestogaugeprogress;regulardialogueandexchange;asharedunderstandingofresearch,development,anddeployment(RD&D)priorities;andcoherentinternationalleadership.ThisreportprovidesaframeworkforsupportingcoordinationoncarbonneutralitybetweentheUnitedStatesandChina,identifyingsharedtechnologypathways,commonmilestones,andpriorityareasfordialogue,RD&D,andinternationalleadership.Theanalysisinthereportisbasedonareviewofrecentmid-centurydeepdecarbonizationandcarbonneutralitystudiesfortheUnitedStatesandChina.Inbothcountries,thesestudieshavebeguntoshedlightonthekindsandpaceoftechnologicaltransitionsneededtoachievecarbonneutralitybymid-century.Despitetheirdifferentnationalcontexts,theUnitedStatesandChinawillhavesimilarapproachesforachievingcarbonneutrality,reflectedinsix“pillars”thatspanenergy-relatedcarbondioxide(CO2)emissions,non-energyCO2emissions,andCO2sequestration(Figure1).AlthoughthisreportfocusesonCO2emissions,significantreductionsinnon-CO2GHGemissionswillalsobenecessaryinbothcountriesbymid-centurytolimitincreasesinglobalaveragetemperatures.11Non-CO2GHGreductionscouldbeincludedinPillar5.Figure1SixPillarsForAchievingCarbonNeutrality4Pillar1EnergydemandreductionsPillar2ElectricitydecarbonizationEnergy-relatedCO2emissionsPillar3FuelsdecarbonizationPillar5Non-energyCO2reductionsPillar6CO2sequestrationOurreviewofrecentstudiessuggeststhat,foreachpillar,theUnitedStatesandChinaareexpectedtohavesimilarhigh-levelstrategiesforreachingtheircarbonneutralitygoals,describedinTable1.Intandem,andinbothcountries,thesestrategiescouldresultin80%to90%reductionsinfossilfuelconsumptionbymid-century,relativetocurrentlevelsofconsumption.HigherlevelsofremainingfossilfuelconsumptionwouldtranslateintogreaterrelianceongeologicalCO2sequestration.Similarlong-termgoalsandhigh-levelstrategiessuggestthattheUnitedStatesandChinacandevelopsharedcarbonneutralitymilestonesfor2030,2040,and2050-2060.Unlikeinternationalcommitments,milestonesaretransparent,non-bindingmeasuresofprogresstowardlong-termgoals.Theyhelptosetminimumlevelsofpolicyambitionovertime,providingaclearsignaltoproducersandconsumersontheexpectedpaceandscaleoftechnologicalchange.Havingasharedsetofmilestonesforbothcountrieswouldprovideapowerfulcommonpointofreference,facilitatinginnovation,largermarkets,andcostreductionsforzeroemissionstechnologies.ThisreportproposessevencategoriesofcommonmilestonesandtargetlevelsfortheUnitedStatesandChinain2030,2040,and2050-2060(Figure2).Theproposedtargetlevelsforeachcategoryofmilestonearelargelythesameforbothcountries,andareconsistentwithnationalandprovincialpoliciesinChina,state-levelpoliciesandproposedfederalpoliciesintheUnitedStates,andlonger-termcarbonneutralitygoalsinbothcountries(Section3.4,Milestones).Theadvantageofcommontargetlevelsforbothcountriesisinthepowerofitssimplicity.However,eveniftheUnitedStatesandChinachoosedifferenttargetlevelsforthesemilestones,havingcommonly-definedmeasuresofprogresswoulditselfbeasignificantachievement.Thesemilestonescanguidebothnationalandstate-provincialpolicyandcanbeadaptedandupdatedovertime.Measuredintermsofnationalpoliciesfor2025and2030,ChinaisclosertobeingonatrajectorytomeetthesetargetmilestonelevelsthantheUnitedStates,whichcurrentlylacksanationalclimatepolicyframeworkorcoherentsector-specificpolicies.Intermsofstate-andprovincial-levelimplementation,however,leadingU.S.statesareinastrongerpositiontomeetmilestonesthantheircounterpartsinChina.SeveralU.S.states,suchasCaliforniaandNewYork,havedevelopedexpertiseinlong-termplanning,policymaking,andregulationinresponsetocarbonneutralitygoals.InChina,provinceshaveonlyjustbeguntodeveloptheplanning,policymaking,andinstitutionalcapacitytomeetanationalcarbonneutralitygoal.ThesedifferencessuggestthattheUnitedStates’andChina’sstrengthsarecomplementaryandprovideastrongrationaleforsubnationalcollaborationasacomplementtocollaborationatthebilaterallevel.PILLARHIGH-LEVELSTRATEGY1.EnergydemandreductionsFlatteningorreducingpercapitafinalenergyconsumptionthroughelectrification,end-useefficiency,andconservation2.ElectricitydecarbonizationReducingCO2emissionsfromelectricitygenerationbymorethan95%by20503.FuelsdecarbonizationReducingCO2emissionsfromsolid,liquid,andgaseousfuelsbymorethan50%by20504.ElectrificationDoublingtotriplingeconomy-wideelectrificationratesby20505.Non-energyCO2emissionreductionsReducingCO2emissionsfromindustrialprocessesthroughprocessormaterialschangesorcarboncaptureandstorage(CCS)6.CO2sequestrationMaintainingorexpandingterrestrialCO2sinksanddevelopinggeologicalCO2sinksTable1High-LevelStrategiesForAchievingCarbonNeutralityByPillar5Toachievenearer-andlonger-termmilestones,theUnitedStatesandChinawillneedtoovercomearangeofpolicyandtechnologygaps,fromtheinstitutionalchallengesofexpandingrenewablegenerationtoterawatt(TW)scaletothemanufacturingandadoptionchallengesarounda20-foldincreaseinelectricvehicle(EV)salesby2030.Atahighlevel,thetwocountrieshavesimilargaps,particularlytechnologygaps,eventhoughtheireconomic,societal,anddemographiccontextsarequitedifferent(Section3.5,KeyTechnologyStrategies,PolicyFocus,andPolicyandTechnologyGaps).SimilarpolicyandtechnologygapsunderscorethevalueofU.S.-Chinacoordinationoncarbonneutrality:Iftheworld’stwolargesteconomiescandirecttheirattentionandresourcestothesameproblemsatthesametime,eveniftheyworkinparallel,thechancesoffindingsolutionswillbemuchhigher.Tothisend,weidentifyfourpotentialareasofU.S.-Chinacoordination.•Commonmilestoneswhichwouldprovideclearsignalstoproducersandconsumersandwouldcreatelargermarketsforzeroemissiontechnologiesthatencourageinnovationanddrivedowncosts.Figure2RecommendedCarbonNeutralityMilestonesfortheUnitedStatesandChina30%0%10%20%30%40%50%60%70%80%90%100%36%CNCNCNCNUSUSUSUS0%2%~0%5%3%50%70%90%100%20305%204030%60%100%203050%2040100%65%2040203030%204070%90%100%203015%204040%80%90%20304204082050-20601253%2030U.S.Milestones80%70%80%Shareofnon-fossilgenerationintotalelectricitygenerationElectricityShareoflow-carbonfuelsintotalfuelsFuelsZEVsalesshareoftotalon-roadpassengervehiclesalesPassengerTransportZEVsalesshareofon-roadfreightvehiclesalesFreightTransportPercentreductioninyear2019industrialCO2emissionsIndustryNetincreaseinforestvolume(Bm³)ForestryShareofelectricityinbuildingfinalenergyconsumptionBuildingsNotes:Verticalgreybarsrepresentbaseyear(2018)values,whereapplicable.Targetvaluesforeachperiodareshownbeloweachperiodmarker.Seethemaintextforsourcesandhowthesevaluesweredetermined.204033%45%203060%90%100%2050-20602050-20602050-20602050-20602050-20602050-206020302040ChinaMilestones6•Dialogueandtechnicalexchangewhichwouldseektobuildconfidenceandtrust,createsharedunderstandingoftechnologypathwaysandhigh-levelstrategiestoachievecarbonneutrality,andshareimplementationexperience.•RD&DprioritizationwhichwouldidentifycommonandcomplementarypriorityareasforRD&Dspending,helpingtofocusRD&D,encouragehealthycompetition,andincreasethechancesofbreakthroughtechnologies.•InternationalleadershipwhichwouldpromotesolutionsforreducingCO2emissionsininternationalshippingandaviation,seektoalignU.SandChinainterestsoninternationaltechnologytransferanddevelopmentassistance,andbeginconversationsaroundthecreationofasystemofinternationalgovernancefortheglobalCO2sink.ActivitiesinthesefourareascouldtakeplacethroughaCarbonNeutralityWorkingGroup,anaturalsuccessortotheU.S.-ChinaClimateChangeWorkingGroup(2013-2017).ThisWorkingGroupcouldcomplementregulartrilateraldialoguewithEuropeandsupportongoingglobalclimatenegotiations.CoordinationoncarbonneutralitydoesnotrequiretheUnitedStatesandChinatoresolvetheirdifferencesaroundtradeandintellectualproperty,thoughdoingsowouldlikelyreducethecostsofmeetingGHGemissionsgoalsinbothcountries.Instead,itonlyrequiresthatthetwocountriesrecognizethattheyhavecommongoals,similarpathstoachievingthosegoals,andasharedinterestinharmonizingthepaceandscaleoftechnologicalchangealongthosepaths.Byworkingtogether,theUnitedStatesandChinawillbeabletoachievefarmorethaneithercountrycouldinisolation.7CHAPTERONEINTRODUCTION1.1ReportOverviewTheIntergovernmentalPanelonClimateChange(IPCC)projectsthatmeetingtheParisAgreementgoalsof“holdingtheincreaseintheglobalaveragetemperaturetowellbelow2°Cabovepre-industriallevelsandpursuingeffortstolimitthetemperatureincreaseto1.5°Cabovepre-industriallevels”willrequireallcountriestoachievenetzeroCO2emissionsbyaroundthemiddleofthiscentury,withsignificantaccompanyingreductionsinnon-CO2greenhousegas(GHG)emissions.2FortheworldtoachieveGHGemissionreductionsonthisscalebymid-century,theUnitedStatesandChinamustplayleadingrolesinpolicy,technologicalinnovation,investmentandtechnologyadoption,andinternationalgovernance.Together,thetwocountriescurrentlyaccountformorethan40%ofglobalfossilfuel-relatedCO2emissions(Figure3).Giventhescaleandscopeofthisemissionreductionchallenge,neithercountrywilllikelybeabletosucceedandleadwithouttheother;ataminimum,coordinationandsomelevelofcooperationbetweenthemwillbecritical.Inthenearterm,themostimportantareasofU.S.-Chinacoordinationwillbeinidentifyingcommonmeasuresofprogress,establishingregulardialogueandtechnicalexchange,developingashared2IPCC(2019).8Figure3FossilFuel-RelatedCO2Emissions,China,U.S.,andRestofWorld,1970-2019Source:DataarefromtheEmissionDatabaseforGlobalAtmosphericResearch(EDGAR)database,https://www.eea.europa.eu/themes/air/links/data-sources/emission-database-for-global-atmospheric.understandingofprioritiesforRD&D,andcoordinatinginternationalleadership.Coordinationcanbuildtrustandconfidence,createlargermarketsforzeroemissionstechnologiesanddrivereductionsintheircosts,facilitatedialoguearoundcommonproblems,focusandincreasethescaleofR&Dfor“missing”technologies,spurCO2emissionreductionsininternationalaviationandshipping,supportGHGemissionreductionsandincreasesinterrestrialsinksinmiddle-incomecountries,andfurtherthedevelopmentofinstitutionsneededforinternationalgovernanceofCO2sinks.ThisreportdevelopsaframeworktosupportcoordinationbetweentheUnitedStatesandChinaonmid-centurycarbonneutralitygoals,drawingonreviewsofrecentdeepdecarbonizationandcarbonneutralpathwaysstudiesinbothcountries.Theframeworkfocusesonthreeareas:•Strategiesandmilestones.Whatarethedifferenttechnologystrategiesandmilestones(2030,2040,2050-2060)thatwouldbeneededtoachievecarbonneutralityinbothcountriesbyaroundmid-century?•Policyandtechnologygaps.Whatarethetechnologicalandpolicygapstoachievingcarbonneutrality?•Opportunitiesforcoordination.WhereshouldtheUnitedStatesandChinafocustheircollaborativeefforts?Thereportincludesfoursections:•Introductionwhichprovidesanoverviewofthereportanditsmotivation,aswellasadefinitionofcarbonneutralityusedthroughoutthereport.•FrameworkBuildingBlockswhichdescribesthefivemainelementsofourframeworkforU.S.-Chinacoordination:pillars,sectorsandactivities,timehorizons,policystrategies,andmilestones.•ASharedFrameworkandMilestonesforCarbonNeutralitywhichcompareshigh-levelstrategiesforcarbonneutrality,developsintermediateandlong-termmilestonesforbothcountries,andidentifiesareasforcoordination.•Conclusionswhichoffersconcludingthoughts.TheanalysisinthisreportissupportedbyreviewsofrecentdeepdecarbonizationandcarbonneutralpathwaysstudiesinboththeUnitedStatesandChina,whicharecompanionreportsinthisseries.31.2MotivationThisreportrespondstoacombinationofneedandopportunity.Inits2019report,GlobalWarmingof1.5°C,theIPCCemphasizedthe2020sasacriticaltransitionperiodforreorientingnationalenergyandindustrialsystemstomeettheParisAgreement’stemperaturegoals.4Duringthelastfiveyears,innovationsinenergyandinformationtechnologieshavedrivendownthecostofrenewableenergy,zeroemissionvehicles,andbuildingenergytechnologiestolevelsthathavemadethemincreasinglycost-competitivewithfossilfuelalternatives.Since2018,bothofthesefactorshavecontributedtogovernments’increasedclimatepolicyambition.3Lokenetal.(2021);Khannaetal.(2021).4TheIPCCprojectedthat“Avoidingovershootandrelianceonfuturelarge-scaledeploymentofcarbondioxideremoval(CDR)canonlybeachievedifglobalCO2emissionsstarttodeclinewellbefore2030(highconfidence).”IPCC(2019),p.18.9InChina,thisincreasedambitionisreflectedinrecentnationalcommitments.InSeptember2020,China’sPresidentXiJinpingpledgedthatChinawouldachievecarbonneutralitybefore2060andwouldpeakCO2emissions“before”2030,insteadof“by”2030perChina’scommitmentundertheParisAgreement.5IntheUnitedStates,climateandenergypolicyambitionhasbeendrivenbyasubsetofstates.Since2018,agrowingnumberofstates—California,Hawaii,Louisiana,Maine,Massachusetts,Michigan,Montana,Nevada,NewYork,Virginia,andWashington—havecommittedtocarbonneutralitygoalsbymid-century.6Alargernumberofstateshavesetmid-century100%cleanenergygoals.7Atafederallevel,theBidenadministrationsignedanexecutiveorderinJanuary2021committingtheUnitedStatestoa2050carbonneutralitygoal.8Withthisincreasedmomentum,thenexttwotothreeyearspresentawindowofopportunityformakingsubstantiveprogressonthetransitionsneededtolimittheimpactsandrisksofclimatechange.1.3DefiningCarbonNeutralityNarrowlydefined,‘carbonneutrality’iswhenanthropogenicCO2emissionsarebalancedbyanthropogenicCO2removalsfromtheatmosphere.9TheUnitedStatesandChinamay,however,definecarbonneutralitydifferently.IntheUnitedStates,statelegislationsincetheearly2000shassetcarbonneutralitytargetsintermsoftotalGHGemissionsratherthanCO2emissions.TheChinesegovernmenthasnotyetspecifiedhowitwilldefinecarbonneutrality.TheIPCC’sanalysisofGHGemissionspathwaystolimitwarmingto1.5°Celsius(C)foundthatglobalanthropogenicCO2emissionswouldneedtoreachnetzerobyaround2050(2045-2055interquartilerange)andnon-CO2GHGemissionswouldneedtofallsignificantlyby2050,butnottozero.10Thisreportdoesnotseektoprovideaprescriptivedefinitionofcarbonneutrality.However,becausethedeepdecarbonizationandcarbonneutralitystudiesthatformtheevidencebaseforthisreportfocusmoreonCO2thannon-CO2gases,thescopeofthisreportislimitedmorenarrowlytoCO2:energy-relatedCO2emissions,non-energyCO2emissions,andCO2sequestration.Thisnarrowerfocusisnotintendedtodiminishtheimportanceofreducingnon-CO2GHGsorsuggestthattheUnitedStatesandChinashouldnotincludenon-CO2GHGsintheirdialogueonclimatechange.InSection3.6(AreasforU.S.-ChinaCoordination),wehighlightareaswhereU.S.-Chinadialogueandexchangeonnon-CO2GHGscouldbefruitful.5MinistryOfForeignAffairs(2020).6Foralistofstategoals,seeNaturalResourcesDefenseCouncil,“Raceto100%Clean,”https://www.nrdc.org/resources/race-100-clean,andCenterforClimateandEnergySolutions,“U.S.StateGreenhouseGasEmissionTargets,”https://www.c2es.org/document/greenhouse-gas-emissions-targets/.7Ibid.8TheWhiteHouse(2021).9Rogeljetal.(2015).10IPCC(2019).10CHAPTERTWOFRAMEWORKBUILDINGBLOCKSEventhemostexpertobserverin1980couldhavebeenforgivenforfailingtoaccuratelypredictthechangesinglobalenergysupplyanddemandthatwouldemergeoverthenextfourdecades:aplateauinglobalenergydemandfollowingthefalloftheSovietUnionin1991;therapidriseindemandfollowingChina’sascensiontotheWorldTradeOrganizationin2001;sustained,innovation-ledgrowthinglobalnaturalgassuppliesoverinthe2000sand2010s;chronicconstructionandsafetysetbacksslowingthedevelopmentofnuclearpower;andimpressivegrowthinsolarphotovoltaic(PV)andwindenergyinthe2010swithaccompanyingsteepdeclinesintheircosts.Thesamewillundoubtedlybetrueforthenext30to40years:thetechnologiesof2060,andthesocietalforcesthatwillshapethem,arebeyondthereasonablelimitsofprognostication.Thatbeingsaid,long-termplanningand“visioning”willbeindispensabletothesuccessofaglobalprojectasambitiousasthetransformationoftheworld’senergy,industrial,andlandusesystemsoverlessthanhalfacentury.Achievingglobalcarbonneutralitybymid-centurywillentailalevelofongoingfocusandsocio-technology“forcing”thatisunparalleledinhumanhistory.Itwillrequiresecular,sustainedreductionsinCO2emissionsovertimethroughcontinuousreplacementoffossilfueltechnologiesandlimitsonindustrialsourcesofCO2.Thismeansstepchangesratherthanincrementalchange—zeroemissionvehiclesratherthanincrementalimprovementsinthefuelefficiencyofinternalcombustionenginevehicles,forinstance.Withoutlong-termplanningthatexploresthemagnitudesandkindsofchangesintechnology,institutions,andbehaviorrequiredtoachievesteepreductionsinCO2emissions,carbonneutralitywillbeanelusivegoal.Long-termplanningprovidesameanstomaintainfocus,aworkingunderstandingoftherequiredpaceandscaleoftechnologicalchange,andanevidentiarybasisforpolicystrategies.Long-termplanningstudiesalsounderpintheframeworkandmilestonesinthisreport.TheUnitedStatesandChinawilltakedifferentpolicyapproachestocarbonneutrality.Thetwocountries’differencesineconomy,demography,administration,andpoliticaleconomymeanthatpolicystrategiesthatareeffectiveinonecountrymaynotbeasrelevantintheother.Despitetheirdifferentpaths,manyofthecoretechnologiesneededtoachievecarbonneutralitywilllikelybethesameintheUnitedStatesandChina,andindeedglobally.Commonzeroemissiontechnologiesaretheresultofacommonglobalgoalandaninterconnectedworldwhere,despiterecentprotectionism,internationaltradetendstoleadtotechnologyconvergence.HavingcommontechnologiessuggeststhattheUnitedStatesandChinacandrivetechnologicalinnovationandcostreductionsthroughstrategiccoordinationthatleadstofocused,large-scaleRD&D,largermarkets,andmanufacturingeconomiesofscaleforzeroemissionstechnologies.Thismodel,wheretheUnitedStates,China,andtheEuropeanUniondevelopandbuydownthecostsoftechnologiesneededtoreduceCO2emissionsinmiddle-incomecountries,isimplicitinmid-centurygoals.Withoutlowercosts,themiddle-incomecountriesthatwillaccountformostoftheworld’sgrowthinCO2emissionsto2050areunlikelytosacrificeeconomicgrowthinordertoreduceCO2emissions.Thus,withoutaggressiveeffortstospurinnovationinandreducethecostsofzeroemissionstechnologies,theUnitedStates’andChina’smid-centurygoalsarelessmeaningfulbecausemiddle-incomecountriesarelesslikelytofollowtheirlead.11Coordinationonlong-termcarbonneutralityplanningbetweentheUnitedStatesandChinawillbeakeyelementofzeroemissionstechnologyinnovationandcostreductions.Coordinationoncarbonneutralitydoesnotrequirejointplanning,policymaking,orinvestment.Itonlyrequiresasharedunderstandingoftechnologypathwaysandsectoraltransitions,whichinturncansupportcommonmeasuresofprogress,dialogueandexchange,somedegreeofalignmentonRD&Dpriorities,andsynchronizedstrategiesforinternationalleadership.Thisreportaimstoprovideafoundationforthiskindofcoordination.Ourframeworkforcarbonneutralitycoordinationhasfivecomponents:1.Pillars;2.Sectors;3.Timehorizons;4.Policystrategies;5.Milestones.2.1Pillars“Pillars”arehigh-levelstrategiesforreducingGHGemissions.11Althoughdifferentstudiesidentifyandfocusondifferentpillarsbasedonnationalorlocalcontext,therearegenerallysixpillars:energydemandreductions,electricitydecarbonization,fuelsdecarbonization,electrification,non-energyCO2emissionreductions,andCO2sequestration.Eachpillarcanbeassessedthroughhigh-levelmetrics(Table2).Thesemetricsareusefulanalytically,butinsomecasesmaynotbethemostusefulindicatorsofprogress(seeMilestones).Thecontributionsofthesedifferentpillarsvaryacrossdifferenttechnologypathways.Forinstance,atechnologypathwayforreachingcarbonneutralitythatreliesmoreonelectrificationwillhavelessrelianceonlow-carbonfuels.Atechnologypathwaythathaslargerresidualenergy-relatedCO2emissionswillneedhavehigherCO2sequestrationtoachieveneutrality.ThepillarsandtheirmetricsprovideareasonablysimpleandstraightforwardwaytocalculatetotalnetCO2emissions(NC).Thebelowequationfirstcalculatesfinalenergyconsumptionastheproductofpercapitafinalenergyconsumption(PE)andpopulation(PP),multipliesfinalenergyconsumptionbytheshareofelectricity(α)andfuels(1-α)infinalenergyconsumptionandtheirrespectivegrossemissionfactors(EFeandEFf),12andthenaddselectricandfuelCO2emissionstonon-energyemissions(NE)andsubtractssequesteredCO2emissions(CS).13Tobecarbonneutral(NC=0),theamountofCO2sequesteredmustequalenergy-relatedandnon-energyCO2emissions.Althoughcountrieshavenotyetestablishedmoreformaldefinitions,mostlikelycarbonneutralitywillbedefinedasnetzeroCO2emissionsoversomeperiodoftime—forinstance5or10years—toaccommodateannualvariabilityintheterrestrialCO2sink.11Williamsetal.(2012);Williamsetal.(2014).12Therewillbeoverlapbetweentheelectricityandfuelemissionfactorsbecauseelectricitymaybeusedtoproducelow-carbonfuels,suchashydrogenviaelectrolysis.SeparateelectricityandfuelemissionfactorscanbecalculatedbyfirstcalculatingCO2emissionsforfinalelectricityandfuels,basedonemissionfactors,andthendividingthesebyfinalelectricandfuelenergyconsumption.GrossCO2emissionfactorsheredonotincludecarboncaptureandstorage(CCS)atenergyfacilities,whichisincludedseparatelyinCS.AnalternativeapproachwouldbetousenetCO2emissionfactors(netofCCS)andthenlimitCStoCO2sequestrationthatisnotassociatedwithenergyconversion,suchasdirectaircapture.13CSherewouldalsoincludecarbonsequesteredinbuildingmaterialsandplastics.12Thisframeworkofpillarsandmetricscapturesthetradeoffsinpolicystrategiestoachieveacarbonneutralitytarget(Figure4).Forinstance,higherfinalenergyconsumption(lessenergydemandreductionthroughelectrification,end-useefficiency,andconservation)requireshigherelectricityandfuelsdecarbonization(lowerEFvalues),morenon-energyCO2emissionreductions(lowerNEvalues),andagreaterrelianceonCO2sinks(greaterCSvalues).Higherfossilfuelconsumption(lowerelectricityandfuelsdecarbonization)requiresmoreenergydemandreduction,morenon-energyCO2emissionreductions,andagreaterrelianceonCO2sinks.Figure4IllustrationofTradeoffsinPolicyStrategiesFECαEFeEFfNECSLessenergydemandreduction(FEC,PE×PP↑)↑↓↓↓↑Lowerelectrification(α↓)↓↓↓↓↑Lowerelectricitydecarbonization(EFe↑)↓↓↑↓↓↑Lowerfuelsdecarbonization(EFf↑)↓↓↓↑↓↑Lessnon-energyCO2emissionreduction(NE↑)↓↓↓↑↑Notes:FECisfinalenergyconsumption,istheeconomy-wideelectrificationrate,EFeistheelectricityemissionfactor,EFfisthefuelemissionfactor,NEisnon-energyCO2emissions,andCSisCO2sequestration.13PILLARMETRICMETRICUNITENERGYDEMANDREDUCTIONReducingenergydemandthroughelectrification,end-useefficiency,andconservationPercapitafinalenergyconsumptionGJ/personELECTRICITYDECARBONIZATIONReducingCO2emissionsfromelectricitygenerationbyincreasingtheshareofnon-fossilgenerationGrossemissionsintensityoffinalelectricityconsumptiontCO2/TJFUELSDECARBONIZATIONReducingCO2emissionsfromfuelsthroughincreasingtheshareofnon-fossilenergyinfuelsGrossemissionsintensityoffinalfuelconsumptiontCO2/TJELECTRIFICATIONIncreasingtheshareofelectricityconsumptioninbuildings,transportation,andindustryElectricityshareoffinalenergyconsumption%FECNON-ENERGYCO2EMISSIONREDUCTIONReducingnon-energyCO2emissionsfromindustrialprocessesAnnualCO2emissionsfromindustrialprocessesMtCO2/yrCO2SEQUESTRATIONPermanentlysequesteringCO2emissionsinterrestrialecosystemsorgeologicalsinksAnnualterrestrialorgeologicalCO2sequestrationMtCO2/yrUnits:GJisgigajoules,tCO2ismetrictonsofCO2andMtCO2ismillionmetrictonsofCO2,TJisterajoules,FECisfinalenergyconsumption,yrisyear.Notes:Thedefinitionsoffinalelectricityandfinalfuelconsumptionshouldbeconsistentwiththatusedinelectrificationinitstreatmentofenergyconversionanddistributionlosses.Non-energyusesoffuels,suchasfeedstocks,aretypicallyincludedinfinalenergyconsumptionandwouldthusbein“fuels.”Table2SixPillarsandTheirMetrics2.2SectorsFromasectoralperspective,netCO2emissionreductionscanbeorganizedintotwoenergysupplysectors(electricity,non-electricfuels),threeenergy-endusesectors(buildings,industry,transportation),non-energyCO2emissions,andtwoCO2sinks(terrestrialandgeologicalCO2sequestration).CO2emissionswithintheenergyend-usesectorsaredrivenbyenergyconsumingactivities.Forinstance,traveldemandandmodalsharesdrivetransportationenergyuseandemissions.Figure5showsactivitydriversforeachend-usesectorandtheirrelationshiptoenergyend-useandsupplysectors.Overaperiodofthreetofourdecades,activitydriversarehighlyuncertain,highlightingtheimportanceofadaptivepolicyandplanning.Reductionsinactivitydrivers,forinstancelowertraveldemandfromtelecommutingorreducedindustrialenergyintensityduetolowermaterialsthroughput,arealsoanimportantformofconservationandarepartoftheenergydemandreductionspillar.2.3TimePeriodsAfocusedapproachtoreducingCO2emissionsoverthreetofourdecadesrequiresasenseofthepaceandsequencingoftechnologicalchangeovertime,whichcanbeaidedbyorganizingthe2020to2060timehorizonintodiscreteperiods.Inthisreport,weorganizetimeintothreephases,showninFigure6.PhaseIcoversthetimeperiodbetween2020and2030,withamilestonedatein2030.Phase2coverstheperiodbetween2030and2040,withamilestonedatein2040.PhaseIIIcoversthetimeperiodbetween2040and2060,withalongertimehorizonthatcapturesthefinalyearsofallcarbonneutralitygoals.Eachphaserequiresadifferentpolicyfocusandwillposedifferentchallenges.Figure5ActivityDrivers,End-UseSectors,andEnergySupplySectors142.4MilestonesRegardlessofnationalcontext,theendpointforcarbonneutralitygoalsisthesame:netzeroCO2emissions.Thefactthatcountriessharesimilartimelinesandtechnologiesforcarbonneutralitysuggeststhat,atahighlevel,theyshouldhavesomecommonmilestones.Forinstance,whatpercentageofelectricityshouldcomefromnon-fossilsourcesby2030and2040?BecausethepaceofCO2emissionreductionsislimitedbythephysicalandfinancialinertiaofinfrastructureandequipmentturnover,milestonesarealsolikelytobebestframedintermsofongoingstepchanges.Milestonesprovideameanstoenvisiontechnologychangeovertimeandgaugeprogressagainstlong-termgoals.Figure7illustratesthisaspectofmilestones,showingkeymilestonesinCalifornia’slong-termdecarbonizationplanning.Figure6IllustrationofThreePhases15Figure7IllustrationofKeyMilestonesinCalifornia’sDecarbonizationPlanningSource:FigureisfromE3,basedondatafromMahoneetal.(2018).Inthisreport,wedevelopasetofcommonmilestonesfortheUnitedStatesandChina,acrosssectors,foreachofthetimeperiodsidentifiedabove.Thesecommonmilestonesarenotintendedtobeatemplateforbindingcommitmentsandcanbeadaptedovertimeastechnologieschange.Nevertheless,milestonesdoprovidetransparency,high-levelaccountability,andmetricstotrackprogress.2.5PolicyFocus‘Policyfocus’referstothefocusofpoliciestosupportthecommercializationanddeploymentofzeroemissiontechnologiesindifferentsectorsduringdifferenttimeperiods.Policyfocuscanbeorganizedintothreecategories:deployment,markettransformation,andRD&D(Table3).Asectormayhavemorethanoneareaofpolicyfocusduringatimeperiod,butitwillgenerallyhaveadominantfocus.Forinstance,asdiscussedbelow,theelectricitysectorhascommerciallyavailable,scalablezeroemissiontechnologiesbutrequirescontinuedRD&Dtodeveloptechnologiestomanagesolarandwindvariabilityanduncertainty.Inthiscase,deploymentisadominantpolicyfocuswhileRD&Disasecondarypolicyfocus.POLICYFOCUSDESCRIPTIONEXAMPLERD&DZeroemissiontechnologiesstillrequiresignificantRD&DbeforetheywillbecommerciallyviableAdvancedbiofuelsMarkettransformationZeroemissiontechnologiesmaybeclosetocommercialviabilitybutrequiresignificantpolicysupport,forinstance,toenablesupplychaindevelopmentormanufacturingscaleHydrogenDeploymentZeroemissiontechnologiesarecommerciallyviableandscalablebutmayrequiresomepolicysupportSolarPVTable3PolicyFocusAreas16CHAPTERTHREEASHAREDFRAMEWORKandMILESTONESFORCARBONNEUTRALITY3.1KeyDifferencesbetweentheUnitedStatesandChinaTheUnitedStatesandChinahavemyriaddifferences,fromeconomytoindustrialorganization,thatwillshapetheircarbonneutralitypathways.Anunderstandingofsomeofthemorefundamentaldifferencesisimportantforcontextualizingtheframeworkandmilestonesinthissection.EconomicStructureAndEnergyConsumption.Overthelastfourdecades,China’sremarkableeconomicgrowthhasbeendrivenbyinvestment,ontheexpendituresideofgrossdomesticproduct(GDP)andindustry,ontheproductionsideofGDP.ThisindustrialorientationoftheChineseeconomymeansthatindustryisasignificantlylargershareofenergyandCO2emissionsinChinathanintheUnitedStates(Figure8).ItalsomeansthatwhatisarguablyChina’smostimportantclimatepolicystrategy,theshifttowardaconsumption-drivenandservices-orientedmodelofeconomicgrowth,islessrelevantfortheUnitedStates.Industrialorganization.InChina,manyofthefirmsthatwillbemostaffectedbyclimatepolicy—electricitygenerators;gridcompanies;fossilfuelproducersandrefiners;steel,cement,andchemicalproducers—arefullyorpartiallystate-owned,whereasintheUnitedStatestheyareamixtureofprivatefirmsandregulatedutilities.Additionally,agricultureandforestryinChinaare17Figure8ComparisonofEnergy-RelatedCO2EmissionsinChinaandtheUnitedStates,2019Sources:EmissionsforChinaarefromLBNLestimates.DatafromtheUnitedStatesarefromEnergyInformationAdministration,“U.S.Energy-RelatedCarbonDioxideEmissions,2019,”https://www.eia.gov/environment/emissions/carbon/.0%20%40%60%80%100%U.S.ChinaShareofEnergy-RelatedCO2EmissionsIndustryBuildingstypicallymuchsmallerscaleandoftenmoresubsistence-orientedthanintheUnitedStates.Thesedifferencesinindustrialorganization,politicaleconomy,andlevelofeconomicdevelopmentwillresultindifferentpolicyapproachesandtoolstoachievethesamesectoralgoal,suchasincreasingnon-fossilgenerationorincreasingforestarea.Energyresourceendowments.ThemostimportantdifferenceinenergyresourceendowmentsbetweentheUnitedStatesandChinaisChina’scurrentlackoflow-costnaturalgasreserves,whichhasseveralimplications.Itmeansthattheshiftfromprimarycoaltonaturalgasuseinindustry,buildings,andelectricitythattookplaceintheUnitedStatesthroughoutthe20thcenturymaybealessattractivestrategyforimprovingairqualityandreducingCO2emissionsinChina.Additionally,itmaymeanthatstrategiesto“firm”renewableenergyinChina’selectricitysectorwillbedifferentthanintheUnitedStates,wherenaturalgasgenerationisoftenassumedtoprovideareliable,backup(lowutilization)energyresourceevenin2050.14Infrastructureageandgrowth.Fromtheperspectiveoflong-livedinfrastructure,suchaspowerplants,distributionnetworks,roads,factories,andbuildings,ChinaisamuchyoungercountrythantheUnitedStates.Forinstance,theaverageageofcoal-firedpowerplantsintheUnitedStatesisabout45years,whereasinChinaitisaround15years.15Additionally,China’sinfrastructureisexpectedtocontinuetoexpandmorerapidlythanintheUnitedStatesoverthenext10to20years.China’syoungerinfrastructureimpliesthatthepaceoftechnologicalchangeinChinamightbeslowerthanintheUnitedStates,butChina’shigherexpectedgrowthimpliesthatitwillbeparticularlyimportantinChinatoalignnewinfrastructureinvestmentswithlong-termcarbonneutralitygoals.Demographicsandpopulationdensity.Chinahasamuchlargerpopulation,higherpopulationdensity,andlargercitiesthantheUnitedStates,thoughitislessurbanized.HigherpopulationdensitymeansthatsomeinfrastructurestrategiesandtransportationmodesthathaveproveddifficultintheUnitedStates,suchasdistrictheating,transit,andintercityrail,arethenorminChina.Thesehigherdensitysolutionslendthemselvestomorecentralizedenergysupplyandlocalinitiativeandlessconcernoverend-useradoption.Forinstance,citiesinChinacansignificantlyreducepassengertransportationCO2emissionsbyprocuringzeroemissionbuses,ratherthanhavingtorelyalmostexclusivelyonpoliciestoencourageadoptionofzeroemissioncars,whichwilllikelybethecaseintheUnitedStates.China’slowerurbanizationrate,60%comparedwith83%intheUnitedStates(2019),meansthatpolicymakersinChinawillplacegreateremphasisonurbaninfrastructure.163.2CarbonNeutralityPillarsIngeneral,theU.S.andChinastudiesreviewedinthisreportdrawconsistentconclusionsonthekindsofstrategies(pillars)andtheirlevelofeffort(metricvalues)forachievingcarbonneutrality.Table4comparespillarmetricsforeachcountryin2050,basedontworecentstudies:a)theCentralscenario(netzeroCO2emissions)fromCarbon-NeutralPathwaysfortheUnitedStates(Williamsetal.,2021)andb)the1.5°CscenariofromChina’sLong-termLow-carbonDevelopmentStrategyandPathway(He,2020).Thesetwostudiesillustratebroadlycommonstrategies:dramaticreductionsintheCO2intensityofelectricity,significantbutsomewhatlowerreductionsintheCO2intensityoffuels,adoublingortriplingofelectrificationrates,andsomeamountofgeologicalCO2sequestration.Differencesinmetricvaluesreflectdifferentpolicystrategies,resourceendowments,and,inthecaseofpercapitaenergyconsumption,differentlevelsofeconomicdevelopmentbetweentheUnitedStatesandChina.Forinstance,higherelectrificationintheChinastudymaybea14See,forinstance,Williamsetal.(2021)andLarsonetal.(2020).15U.S.dataarefromFormEIA-860Data.ChinaestimateisbasedonCarbonTrackerdata.16UrbanizationratedataarefromtheWorldBank’sWorldDevelopmentIndicators,https://databank.worldbank.org/.18consequenceoflowernaturalgasuseinindustry.Table4alsoillustratestherelationshipsamongdifferentpillars.Higheremissionfactors(tCO2/TJ)forelectricityandfuelsintheChinastudyrequirelargerCO2sinkstoreachnetzeroCO2emissions.However,whilethesemetricscanbeausefulbasisforcomparinghigh-levelstrategies,theyarelessmeaningfulforgoalsettingbecausepolicystrategies—forinstance,thelevelofelectrification—mayreasonablydifferacrossgeographiesandovertime.Animportantmetricthatisimplied,butnotexplicitlyreported,inTable4istotalremainingfossilfuelconsumptionin2050andthepercentagereductioninfossilfuelconsumptionin2050relativetocurrentconsumption.AcrosstheU.S.studiesreviewedforthisreport,remainingfossilfuelcombustionin2050rangesfromzerotoaround30EJ(60-100%reductionbelow2020levels).17IntheChinastudies,remainingfossilfuelcombustionin2050rangesfromaround5to25EJ(approximately200to800milliontonsofcoalequivalent(Mtce),80-95%reductionbelow2020levels).18Higherfossilfuelusein2050impliesalargerrelianceongeologicalCO2sequestration,assumingthattherearepracticallimitstoexpandingtheterrestrialCO2sink.Higherremainingnon-energyCO2emissionsalsoimplyhigherlevelsofgeologicalCO2sequestration.Non-energyCO2emissionsinbothcountriesarebothdiverseandsignificant.IntheUnitedStates,theEnvironmentalProtectionAgency(EPA)estimatedthatannualnon-energyCO2emissions17ThisrangeisbasedontheLarsonetal.(2020)E+RE+andE+RE-scenarios,whichencompassestherangesinallotherstudiesreviewedinLokenetal.(2021).18ThisrangeisbasedonmodelresultsreviewedinShaetal.(2020),whichappearstoencompasstherangesinotherstudies.Thepercentagereductionhereassumesfossilfuelconsumptionofaround4,100Mtcein2020,basedonHe(2020).19PILLARMETRICUNITEDSTATESCHINA20182050A20182050BEnergydemandreduction(FECshowninparentheses)GJ/person(EJ)203(66)130(50)60(86)60(85)ElectricitydecarbonizationtCO2/TJ131522410FuelsdecarbonizationtCO2/TJ54256735Electrification%21%50%25%70%Non-energyCO2reductionMtCO2/yr258/1,320250CO2sequestrationGtCO2/yr/0.8/1.7Notes:FECisfinalenergyconsumption.All2050estimatesareroundedtothenearestfive,exceptforCO2sequestration.All2018energyandemissionsdataisbasedonInternationalEnergyAgency(IEA)(2019a)andpopulationdatafortheenergyefficiencypillarmetricisfromtheUnitedNationsDepartmentofEconomicandSocialAffairs(UNDESA)(2019).U.S.non-energyCO2emissionsarefromtheEnvironmentalProtectionAgency(EPA)(2020);Chinanon-energyCO2emissionsisa2020estimatefromHe(2020).ABasedonthe“Central”scenariofromWilliamsetal.(2021).Thestudy’sCO2accountingdidnotincludetheU.S.terrestrialCO2sink.TheCentralscenarioincluded0.5GtCO2ofCO2utilizedinproducts,whichisincludedinCO2sequestrationhere,and53MtCO2ofinternationalbunkeroffsets,whicharenotseparatelyaccountedforinthetable.ThestudyusedCCS,includedinCO2sequestration,toreducenon-energyCO2emissions.BBasedonHe(2020).Thenumbershereassumefinalenergyconsumptionof83EJ(roundedto85EJinthetable)in2050(LBNL,2020),apopulationof1,402billionin2050(UNmediumvariantestimates),andthat40%/60%ofenergy-relatedCO2emissionsin2050arefromelectricity/fuels(basedonthefigureinp.20).Non-energyCO2emissionreductionsinthisstudymayhaveusedCCS,whichmeansthatthenon-energyCO2reductionmetricmaynotbecomparablewiththeWilliamsetal.(2021)study.Table4PillarMetricValuesin2018andIllustrativeValuesin2050,BasedonTwoRecentStudieswere258MtCO2in2018,coveringindustrialprocessesasdiverseascementproductiontosodaashmanufacturing.19Strategiesformitigatingnon-energyCO2,andnon-CO2GHGemissionsmorebroadly,havetraditionallynotbeenafocusofdeepdecarbonizationandcarbonneutralitystudies,andwillneedtobegivenmoreattentionoverthenextdecade.3.3SectoralStrategiesMostsectorshavea“dominant”mitigationstrategy,oramaintechnologyorsetofsimilartechnologiesthatisexpectedtoaccountformostCO2emissionreductions.Inmanysectors,expectationsofwhatthesedominantstrategieswillbearesimilaracrossUnitedStatesandChinastudies,thoughinsomeinstancesexpectationsreflectdifferentassumptionsandstructuraldifferences(Table5).•Intheelectricitysector,solarandwindenergyareexpectedtobethedominantscalablenon-fossilenergyresourcesoverthenextthreedecades.Differencesbetweentheassumedsharesofsolarandwindgenerationin2050reflectChina’slargerhydropowerresourcesanddifferencesinassumptionsaboutthescalabilityofnuclearpowerinChina.20•Thetwodominantstrategiesforlow-carbonfuelsacrossU.S.andChinastudiesincludeasignificantexpansionofbiofueland,toalesserextent,hydrogensupply.ThelargerangesinTable5illustratetheuncertaintyanddifferencesofopinionaroundthehighestvalueusesofscarcebioenergysuppliesandthescalabilityandeconomicsofhydrogenproducedthroughelectrolysis.Inbothcountries,bioenergyisexpectedtoplayamuchlargerroleinenergysystemsthanitdoestoday.•Differencesinsectoralelectrificationratesmayreflectdifferencesinindustrystructureandtechnologies,butalsodifferencesinassumptionsthatmayultimatelyconvergeovertimeastechnologiesandmarketsmature.Forinstance,higherbuildingelectrificationintheUnitedStatesmaybeduetoChina’slargerdistrictheatingnetwork.ThelowerrangeofelectrificationratesinindustryinU.S.studiesandthelowerrangeinChinastudiessuggeststhatindustrydoesnotyethaveacleardominantstrategy.•Inbothcountries,thedominantstrategyforterrestrialCO2sequestrationislikelytobeafforestationandreforestation,thoughthereisstilldebateoverthesizeoftheexistingforestcarbonsinkandthepotentialforexpandingitby2050.TechnologicalinnovationwillmeanthatthedominantstrategiesinTable5willevolveovertime.However,thepathwayto2030isrelativelyclearinbothcountries:usingrenewablegenerationtodecarbonizetheelectricitysector,electrificationinthebuildingandtransportationsectors,landusepoliciesthatencourageCO2sequestration,andinitialeffortstodecarbonizefuelsandachievelargerCO2emissionreductionsinindustry.ThecomparisoninTable5illustratesagainthat,whiletheUnitedStatesandChinamaydifferinthespecificsofsectoralstrategies,toasignificantextenttheirtechnologypathwaystocarbonneutralitywilllikelybesimilar.3.4MilestonesThesharednatureoftechnologypathwayssuggeststhattheUnitedStatesandChinacouldhaveacommonsetofmilestonesby2030,2040,and2050-2060.Weidentifysevenmilestonesmetricsthatareimpactful,willbecommontobothcountries,andarereasonablystraightforwardtomeasureandmonitor.Table6showsthesemilestones,their2018baselinevalues,andproposedtargetvaluesfor2030,2040,and2050-2060.19EPA(2020).20SeeKhannaetal.(2021)forarangeofestimates.20Table5DominantStrategiesand2050MetricValuesbySector,BasedonRecentStudiesNotes:ZEVreferstozeroemissionvehicles,which,withcurrenttechnologies,wouldprimarilybefullelectricvehicles(EVs)andfuelcellvehicles(FCVs).BaselinevaluesarefromIEA(2019a)exceptforZEVsales,whicharefromIEA(2019b).For“on-roadpassenger,”theemphasisisoncarsbutcouldincludebusesaswell;for“on-roadfreight,”theemphasisisonlighterandheaviertrucks.“Totalsales”includesnewvehiclesalesandleases.Chinahadanelectriclightcommercialvehiclefleetofaround140,000vehiclesin2018(IEA,2019b),butintermsoftotalannualfreightvehiclesalesZEVsalesarenegligible.Baseline(2019)industrialCO2emissionswouldincludeprimaryfuelconsumptionandenergyfeedstocks.Wepropose2019asabaselineyearduetothedistortionaryeffectsoftheCOVID-19pandemicon2020industrialemissions.Asdescribedlaterinthetext,werecommendthatthesevaluesbeexpandedtoincludeindustrialprocessCO2emissionsaswell.SECTORDOMINANTSTRATEGY2050METRICU.S.CHINAElectricityScaleupsolarandwindgenerationSolarandwindshareofelectricitygeneration(%)70-90%40-70%FuelsIncreasebiofuelsupplyPrimarybiofuelsupply(EJ)10-15EJ2-10EJIncreasehydrogensupplyDeliveredhydrogen(EJ)2-20EJ5-15EJBuildingsElectrificationElectrificationrate(%)70-90%55-75%TransportationElectrificationElectrificationrate(%)45-55%35-55%IndustryElectrificationElectrificationrate(%)20-50%50-70%TerrestrialCO2sequestrationAfforestationandreforestationAnnualforestsequestration(GtCO2/yr)0.3-1.50.7-0.8Units:EJisexajoulesandGtCO2isgigatonsofcarbondioxide.Notes:Allvaluesexceptforafforestationandreforestationareroundedtothenearestfivebutnottozero.AllvaluesarefromLokenetal.(2021)andthe1.5°CscenariosinKhannaetal.(2021)exceptforfuelsandterrestrialCO2sequestration.PrimarybiofuelrangesintheU.S.arebasedonWilliamsetal.(2021)(lowerrange)andLarsonetal.(2020)(B+scenario)(higherrange).Larsenetal.(2020)allowforupto23EJofprimarybioenergysupplyin2050intheirB+scenario,butaround500TWhisusedforbioenergywithCCS(BECCS)powergenerationandisnotincludedinthistotal.PrimarybiofuelrangesinChinaarefromJiangetal.(2018)(lowerrange),whichassumesmostbioenergyisusedinBECCSpowergeneration,andfromShaetal.(2020)(higherrange).DeliveredhydrogenrangesintheU.S.arebasedonWilliamsetal.(2021)(lowerrange)andLarsonetal.(2020)(higherrange).DeliveredhydrogenrangesinChinaarefromShaetal.(2020).AfforestationandreforestationrangesarefromLarsonetal.(2020)andHe(2020).21Table6CarbonNeutralityMilestonesfortheUnitedStatesandChinaThetargetvaluesinTable6areintendedtobecommonpointsonatransitionpathwayto2050and2060carbonneutralitygoals.Eithercountrycouldexceedthesetargetvalues;21theyofferacommonfloorofambitionforbothcountries.Shareofnon-fossilgenerationintotalelectricitygenerationProposedmilestonesfortheshareofnon-fossilelectricitygenerationintotalgenerationincreaseapproximatelylinearly(1-2percentagepointsperyear)from2018to2050.Becausetheactualamount(TWhenergy)ofnon-fossilgenerationdependsonseveralotherfactors—totalfinalenergyconsumption,theelectrificationrate,andtheamountoffuelsproducedwithelectricity—alinearincreaseintheshareofnon-fossilgenerationwilllikelytranslateintoanon-linearincreaseinthetotalamountofnon-fossilgeneration.22Figure9illustratesthiseffectforbothcountries,basedonthemilestonesinTable6andassumingtheshareofnon-fossilgenerationreaches90%by2050.IntheUnitedStates,a50%non-fossilgenerationshareby2030wouldimplyaroundadoubling(1,600TWhincrease)ofnon-fossilgenerationbetween2020and2030.23Ifsolarandwindgenerationaccountformostofthisincrease,generationfromtheseresourceswouldneedtoincreasefour-foldbetween2019and2030.24A50%shareofnon-fossilgenerationinChinaby2030alsoimpliesaroundadoubling(3,300TWhincrease)ofnon-fossilgenerationby2030andaroundafour-fold(2,900TWh)increaseinsolarandwindgeneration.25Thelatterwouldrequireroughly1.6TWofnewsolarandwindgenerationcapacity(2.1TWtotal)by2030,anincreaseofaround900GWabovetheChinesegovernment’srecent(2020)pledgetoincrease21Forinstance,arecentU.S.NationalAcademiesstudyrecommendedincreasingtheshareofnon-fossilgenerationto75%intheUnitedStatesby2030(NASEM,2021).22Lowerfinalenergyconsumptionwillleadtolowernon-fossilgeneration,butahigherelectrificationrateandmoreelectricfuelswillleadtohighernon-fossilgeneration.Thedynamicsamongthesevariables—decliningorflatteningfinalenergyconsumption,anincreasingelectrificationrate,andslowbutthenrapidincreasesintheshareofnon-fossilenergyinfuels—willlikelytranslateintoanon-linearexpansionofnon-fossilfuelgeneration.23SeeAppendixA.24IntheUnitedStates,solar(includingdistributedPV)andwindgenerated402TWhin2019(EIA,2021).25SeeAppendixA.InChina,solarandwindgenerated728TWhin2020(CEC,2021).22Notes:SeeAppendixAformoredetailonthecalculationsbehindthisfigure.Figure9IllustrationofaLinearChangeintheShareofNon-FossilGenerationandaNon-LinearIncreaseinTotalNon-FossilGenerationsolarandwindgenerationcapacityto1.2TWby2030.26Forthetwocountriestogether,meetinga50%non-fossilgenerationgoalby2030impliesatotalofaround2TWofnewsolarandwindgenerationcapacity,or200GWperyearincreasesininstalledcapacitybetween2020and2030.27Thisamountisroughlyequivalenttoexistingglobalsolarandwindmanufacturingcapacity.28Shareoflow-carbonfuelsintotalfuelsProposedmilestonesfortheshareoflow-carbonfuelsintotalfuelsbeginatlowlevelsandincreaserapidlyin2040and2050.Thisapproachreflectstwoconsiderations:(a)fuelscurrentlyaccountforaround80-85%offinalenergyconsumptioninboththeUnitedStatesandChinabuttheshareandamountoffuelconsumptionisexpectedtodeclineduetoelectrification,whichmeansthatalinearincreaseintheshareofnon-fossilenergywillleadtoanon-linearincreaseintotalnon-fossilenergy;and(b)significantuncertaintyintheavailabilityofbioenergysuppliesandbusinessmodelsforlowcarbonfuels.Figure10illustratesthefirstconsiderationforbothcountries,basedonthemilestonesinTable6andassumingtheshareoflow-carbonfuelsreaches80%by2050.Ineachcountry,a5%milestonefortheshareoflow-carbonfuelswouldtranslateintoroughly2-3EJoflow-carbonfuelsby2030.Ifhalfofthesefuelsarebiomass-basedandhalfarederivedfromelectricity,theprimarybiomasssupplyrequirementswouldbearound2-3EJperyearandtherequiredincreaseinelectricitygenerationwouldbearound900-1,500TWhperyear.Thismoregradualscalingupoflow-carbonfuelswouldallowtimeforsupplychaindevelopment,toaddressconcernsoversustainabilityforbioenergyandtodevelopregulatoryframeworksthatfacilitatebusinessmodels.A30%milestonein2040wouldrequirearound10-15EJoflow-carbonfuelsineachcountry,26SeeAppendixA.Generationcapacityrequirementsdependoncapacityfactorsforsolarandwind,whichinturndependonenergyconversionefficiencyandresourcequality.AtU.S.averagecapacityfactorsforwind(0.35)andsolar(0.25)in2019,forinstance,China’stotalwindandsolarcapacityrequirementsin2030wouldbearound1.4TWratherthan2.1TW.Ultimately,themainreasonthatinstalledcapacityisimportantisduetolanduseimplications.27SeeAppendixA.28IEA(2020a)estimatesthatglobalsolarmanufacturingcapacityin2020was165GW;theIEA(2020b)projectsthatnetwindcapacityadditionsin2020were65GW.23Notes:SeeAppendixAformoredetailonthecalculationsbehindthisfigure.Figure10IllustrationofaNon-LinearChangeintheShareofLow-CarbonFuelsandaNon-LinearIncreaseinTotalLow-carbonFuelsincreasingto20-27EJby2050.29Forreference,intheUnitedStatesbiomassaccountsforaround1EJoffuels,mostlyethanolthatisblendedwithgasoline,withtheremainder(98%)beingfossilfuels.30InChina,outsideoftraditionalbiomassuseinruralareas,biomassuseinfuelsisnegligibleandfossilfuelsaccountfornearly100%offuels.31ItisnotcleartheextenttowhichcurrentbiomassfuelproductionineithercountrycouldbeconsideredtohavenetzeroCO2emissions,whichunderscorestheneedforrigorousandeffectiveregulatoryframeworkstoensurethatbioenergycontributestomitigation,ratherthanexacerbation,ofclimatechange.Inthenearterm,absoluteenergy-based(EJ)milestonesmightbemoremeaningfulthanrelativeshare-basedones,forencouragingthedevelopmentofalow-carbonfuelsindustry.However,overthelongertermshare-basedtargetsaremoreflexibleandmeaningful.Inthelongerterm,thebalancebetweenfuelsversuselectricityandstrategiesfordecarbonizingfuelsshouldbedrivenbyeconomicfundamentalsandarobustregulatoryframework,ratherthanenergy-basedtargets.ZEVsalesshareofon-roadpassengerandfreightvehiclesalesProposedmilestonesforzeroemissionvehicle(ZEV)salesofbothpassengerandfreighton-roadvehiclesimplyasignificantincreaseinsalesofthesevehiclesby2030and2040.Milestonesareintermsofsales(aflow)ratherthantotalvehicles(astock),soifpassengerandfreightvehicleshaveroughly10-15-yearand15-20-yearlifetimes,respectively,thesemilestoneswouldimplythatmostinternalcombustionengine(ICE)passengervehicleswillhavebeenretiredby2050andremainingICEfreightvehiclesretirebetween2050and2060.29SeeAppendixA.30Williamsetal.(2021).31USDA(2020)estimatesthatethanolandbiodieselproductioninChinawere3and0.8billionlitersin2020,equivalenttoaround0.09EJofenergy(21MJ/Lethanol,33MJ/Lbiodiesel).Mostoftheapproximately1EJofbioenergyconsumptioninChinaiseitherconsumedinsolidformorconvertedtoelectricity(Panetal.,2018).24Notes:ZEVsalesinthisfiguredonotincludeplug-inhybrids.ZEVsalesdataarefromDOE(2020)andtheChineseAssociationofAutomobileManufacturers(CAAM).TotalvehiclesalesfortheUnitedStatesarefromtheBureauofTransportationStatistics(BTS)(2020)andforChinaarefromCAAM.U.S.salestotalsalesdataincludebothsalesandleases.Chinatotalpassengervehicleforecaststo2025arebasedonannualaveragegrowthconsistentwith30millionpassengervehiclesalesby2030.ChinaZEVandtotalsalesdataarelimitedtopassengervehicles.Figure11ActualZEVSales(U.S.,China)andPolicyGoals(China)RelativetoaGenericS-ShapedAdoptionCurvethatMeetsMilestonesChina’scurrentpoliciestargeta20%shareof“newenergyvehicles”innewpassengervehiclesalesby2025,whichcouldbeconsistentwitha50%ZEVtargetby2030and100%by2040assumingS-shapedadoption(Figure11).32TheUnitedStatesdoesnothavefederaltargets,policies,orregulationsthatareconsistentwiththislevelofpassengerZEVadoption,butsomestateshavesetorproposedZEVtargetsthatarealignedwithorexceedthesemilestonesandthesemilestoneswereproposedinCongressionallegislationin2019.33Meetingthe2030milestonewouldimplytotalannualZEVsalesofbetween20and25millionvehiclesinbothtwocountriesby2030,amorethan20-foldincreaserelativeto2020ZEVsales.34NeithertheUnitedStatesnorChinahavedevelopednationaltargetsforzero-emissionsfreightvehiclesandsalesofthesevehiclesarestilllow.A30%milestonewouldthusbeambitiousbutisconsistentwithU.S.state-levelpolicies.Forinstance,in2020acoalitionof15U.S.statessignedamemorandumofunderstandingsettingatargetof30%ZEVsalesformedium-andheavy-dutyvehiclesby2030.35ShareofelectricityinbuildingfinalenergyconsumptionProposedmilestonesforresidentialandcommercialbuildingsarebasedonthetotalelectricityconsumedinbuildingsasashareoffinalenergyconsumption.Thismetrichastheadvantageofbeingrelativelyeasytomeasureandregularlypublishedingovernmentenergystatistics.ItsdownsideisthattheUnitedStatesandChinaarestartingatverydifferentbaseyearvalues(33%inChinaversus53%intheUnitedStates)andhavehistoricallytakendifferentapproachestoheatingsystems(districtheatinginChina,naturalgasdistributionintheUnitedStates),whichmakesitdifficulttousethesametargetvalues.Theshareofelectricityinbuildingfinalenergyconsumptioncanincreaseasnewall-electricormostlyelectricbuildingsarebuilt,asexistingbuildingsareelectrified,andthroughreductionsintheamountoffinalenergyconsumedinbuildings.GiventherelativelyslowpaceofnewconstructionrelativetoexistingbuildingsandanS-shapedadoptioncurveforretrofits,theshareofelectricityinbuildingfinalenergyconsumptionwilllikelychangeslowlyatfirst.Theproposedmilestonevaluesworkbackwardfromthe2050electrificationratesinTable5andassumethatincreasesinelectrificationratesfrom2020to2030and2030to2040willbeslower.Evenwithslowerincreasesfrom2020to2030,thesemilestonevaluesimplyeitherthatasignificantfractionofnewbuildingswouldbeall-electricorthatasignificantnumberofexistingbuildingswouldreplacefossilfuel-basedheatingsystemswithelectricheatpumps.ForChina,theyassumethatitwillbemorecost-effectiveinmanycasestoreduceCO2emissionsfrombuildingsthroughelectrificationthanwithdistrictheating.Ifthisprovesnottobethecase,themilestonevaluesin2050-2060andintheintermediateyearswouldbelower.Twoalternativemetricswouldbe(1)theshareofelectricheating,theshareofall-electric,ortheshareofzeroemissionnewbuildings,butthesearemoredifficulttomeasureanddonotcapturetheimportanceofretrofittingexistingbuildings,or(2)buildingCO2intensity(kgCO2perm2peryear),whichisdifficulttomeasureandinterpretbecauseitisanaggregatemeasure(them2inthedenominatoristotalbuildingfloorarea),itoverlapswithelectricityandlow-carbonfuelmilestones(mixesenergysupplyandend-use),andneithercountryregularlyestimatesandreportstotalbuildingarea.32TheMinistryofIndustryandInformationTechnology’s(MIIT’s)definitionof“newenergyvehicles”currentlyincludesfullEVs,plug-inhybridEVs,andFCVs,butwouldneedtobenarrowedtoincludeonlyfullEVsandFCVsby2030tobeconsistentwiththismilestone.33Forinstance,California’sExecutiveOrderN-79-20requires100%ofnewvehiclesalestobeZEVsby2035.Washington’sproposedHB1204/SB5256wouldrequireall2030-modelandlaterpassengercarsandlightdutytrucksregisteredinthestatetobeelectric.Atanationallevel,the2030milestoneisconsistentwithNationalAcademiesrecommendations(NASEM,2021).The2030and2040milestonesareconsistentwiththeZero-EmissionVehiclesAct,whichwasproposedin2019.34Thisestimateassumestotalannualpassengervehiclesalesofaround20millionintheUnitedStatesand30millioninChinain2030,consistentwithindustryforecasts(Schilleretal.,2020),butdoesnotincludevehicleleases.PassengerZEVsales(excludinghybrids)intheUnitedStateswere0.24millionin2019(DepartmentofEnergy(DOE),2020)andinChinawere1.00millionin2020(ChineseAssociationofAutomobileManufacturers(CAAM),2021).35California’sAdvancedCleanTruckProgramrequires30%ofallnewmedium-andheavy-dutyvehiclessoldinCaliforniatobeaZEVby2030and100%by2045.NASEM(2021)alsorecommendsa30%ZEVtargetforheavy-dutyvehiclesintheUnitedStates.25Percentreductioninyear2019industrialCO2emissionsThemilestoneforindustryiscross-sectorandmeasuredinabsolutereductionsratherthanintensity.IndustrialCO2emissionscovermultipleeconomicsectorsthatoftenhaveverydifferentproductionprocessesandemissionssources,butindustrialCO2emissionscanbereasonablywellmeasuredandmonitoredintheaggregate.ThemilestoneisalsobasedonCO2emissionsfromfinalenergyconsumption(notincludingelectricityemissions)andindustrialprocessCO2emissions,whichfocusesontheemissionsthatindustryhasamoredirectabilitytomanage.ThisapproachtodefininganindustrymilestonewouldallowtheUnitedStatesandChinatousearangeofdifferentstrategies—structuraleconomicchange(reducingtheshareofindustryinGDP),end-useefficiency,electrification,fuelswitching,andCCS—toreduceindustrialCO2emissions.TheproposedtargetvaluesassumeasignificantlylargerdeclineinabsoluteCO2emissionsfromindustryinChinafrom2020to2030becauseChina’sindustrialemissionsarearoundfivetimeslargerthanindustrialemissionsintheUnitedStates.36However,intermsofpercentagereductionsinindustrialCO2intensity(CO2emissionsperunitindustrialvalueadded),the2030valueshavesimilarimplicationsforbothcountries.BothwouldneedtoreduceindustrialCO2intensitybyaround35%by2030tomeetthe2030milestoneofa15%reductioninyear2019emissions.37NetincreaseinforestvolumeInbothcountries,thecurrentterrestrialCO2sinkismainlyduetoreforestationandafforestationoverthepasttwodecades.38Expanding,orevenmaintaining,existinglevelsofthissink(0.7-0.8GtCO2/yrineachcountry)overthenext30yearswouldrequireasignificantlevelofforestpolicyeffort.ThemilestonesaimtocapturealevelofCO2sequestrationinforests,involumetricterms,thatisequivalenttomaintainingthecurrentannualforestrysinkforthenextthreedecades.393.5KeyTechnologyStrategies,PolicyFocus,andPolicyandTechnologyGapsAssuggestedbythemilestones,keytechnologystrategieswithindifferentsectorsareatdifferentstagesofthepolicyfocuscategoriesintroducedintheFrameworkBuildingBlockssection.Asaresult,differenttechnologystrategieshavedifferentpolicyortechnologygaps.TheUnitedStatesandChinafacesimilarchallengesforeachtechnologystrategy,asdiscussedbelow,butatthelevelofmoredetailedpolicytheirdifferentchallengesreflectdifferentsocial,economic,andregulatorycontexts.Table7showskeytechnologystrategiesforeachsector,policyfocusforeachstrategy,andpolicyandtechnologygapsforthestrategy.KeytechnologystrategiesarebasedonthedominantstrategiesinTable5buttheend-usesectorsinTable7providemoregranularity.36Thisestimateisbasedonanestimateof7,087MtCO2ofindustrialsector(includingagriculture)emissionsin2019,fromLBNL,andtheEIA’sestimate(EIA,2020)of1,423MtCO2fortheUnitedStatesin2019.Theseestimatesincludeelectricitysectoremissions.TheratioofindustrialprocessCO2emissionsforbothcountriesiscomparabletotheratiooftheirenergy-relatedindustrialCO2emissions:1,320MtCO2inChinain2020(He,2020)and258MtCO2intheUnitedStatesin2019(EPA,2020).37SeeAppendixA.38TheU.S.EPAestimatesthatthenetfluxfor“forestlandremainingforestland”and“landconvertedtoforestland”was-773MtCO2in2019,whichwasequivalenttothetotalnetamountofCO2sequesteredinthatyear(EPA,2020).EstimatesofChina’sterrestrialCO2sinkvarywidely.He(2020)reportsa0.7GtCO2/yrsinkin2020,butWangetal.(2020)estimateChina’slandsinkat3-4GtCO2/yrbetween2010and2016.39Themilestonesassume800MtCO2/yrover30years,acarbonfractionofdrywoodof0.5tC/t,andabiomassconversionexpansionfactorof1t/m3.Thistranslatesto425Mm3/yr(=800MtCO2/(44tCO2/12tC)/(0.5tC/t×1t/m3)ofnewforest,orroughly4Bm3every10years.26TheaccompanyingU.S.andChinareviewstudiesprovidemoredetailonpolicyfocus.40Theremainderofthissectiondescribespolicyandtechnologygapsingreaterdetail.Electricity.Inbothcountries,thesharesinTable5implyTW-scaledevelopmentofsolarandwindresourcesoverthenexttwodecades,whichmaycreatelanduseconflictsandwouldrequireasignificantexpansionofelectrictransmissionsystems.Forinstance,intheir“Central”scenarioWilliamsetal.(2021)projectthattheexpansionofwindandsolarrequiredtomeeta2050carbonneutralitygoalfortheUnitedStateswouldrequire36millionhectaresoflandandwouldentailanear-doublingofinterstatetransmissioncapacity.Toprovideasenseofscale,theUnitedStateshasatotallandareaof915millionhectaresand152millionhectaresofarableland.4140Lokenetal.(2021);Khannaetal.(2021).41DataarefromtheWorldBankWorldDevelopmentIndicators,https://databank.worldbank.org/.27SECTORKEYTECHNOLOGYSTRATEGIESPOLICYFOCUSPOLICYANDTECHNOLOGYGAPSDPMTRD&DElectricityScaleupwindandsolargenerationLandusetradeoffs,integrationobstaclesLackofcost-effectivereliableenergyandlong-durationstoragetechnologiesFuelsIncreasebiofuelandhydrogensupplyHighcost,lackofregulatoryframeworksLackofcost-effectiveadvanced(landefficient)biofueltechnologiesOn-roadpassengertransportElectrificationAdoptionbarriersandnewchargingandelectricitydistributioninfrastructurerequirementsOn-roadfreighttransportElectrificationandfuelswitchingAdoptionbarriersandnewchargingandelectricitydistributioninfrastructurerequirementsBuildingsElectrificationfornewbuildingsAdoptionbarriersandnewelectricitydistributioninfrastructurerequirementsElectrificationforexistingbuildingsHighcost,adoptionbarriers,andnewelectricitydistributioninfrastructurerequirementsIndustryElectrificationandfuelswitchingHighcostandlackofbusinessmodelsLackofcost-effectivealternativeenergytechnologiesforsomeindustrialprocessesTechnologiestoreduceindustrialCO2processemissionsLackofcost-effectivetechnologiesforreducingprocessemissionsForestry/agricultureAfforestation,reforestation,andsoilcarbonsequestrationLackoffunding,monitoring,verification,andcompliancemechanismsGeologicalsinkPowerandindustryCCSLackoffunding,monitoring,verification,andcompliancemechanismsKEYPrimarypolicyfocusSecondarypolicyfocusTable7KeyTechnologyStrategies,PolicyFocus,andPolicyandTechnologyGapsDP=DeploymentMT=MarketTransformationRD&D=Research,Development&DeploymentNeithercountryhasnationalpoliciesthatwouldencouragesolarandwinddevelopmentonthisscale,thoughsomeU.S.stateshavesetbindingintermediateandlonger-termcleanenergygoalsthatcoulddoso.42Inaddition,bothcountriesfaceinstitutionalbarrierstogenerators.IntheUnitedStates,electricutilityregulationisamoreimportantbarriertotherapiddeploymentofsolarandwindgeneration,becauseutilitiesprocurepoweronbehalfofmostelectricitycustomersbutmayalsoownfossilfuelgeneration.RecentstudiesintheUnitedStatessuggestthatelectricitysystemsmaybeabletocost-effectivelyandreliabilityoperatewithnon-fossilpenetrationsapproaching80-90%oftotalgeneration,butbeyondthattheircostswouldrisesignificantlytomaintainexistinglevelsofreliability.43Althoughthischallengecouldberesolvedwithexistingtechnologies,44developingnewlow-costzeroemissionsourcesofreliableelectricitygeneration,suchasadvancednuclearorbiogas,andlong-durationelectricitystoragetechnologieswouldgreatlyreducetherequiredlevelofeffortandcomplexityneededtomeetcarbonneutralitygoals.Fuels.Biofuelsareexpectedtoplayanimportantroleinlow-carbonenergysystemsinbothcountries,buttherearequestionsaroundwhetherbiofuelscanbeproducedatthe5-10EJscaleshowninTable5ineithercountrywithoutnegativelanduseimpactsandcompetitionwithfoodandotherusesofbiomass.AdvancedbiofuelsthataremorelandefficientarethusakeycommonRD&Darea,thoughevenwithinnovationsinbiofueltechnologiesnewregulatoryframeworkswillstillbeneededtoensurethatsustainabilityconcernscanbeaddressed.Costsforliquidbiofuels,biogas,hydrogen,andsyntheticfuelsremaintoohightobecompetitiveanditisnotyetclearwheretheirhighestvalueapplicationswillbe.Policiesandregulatoryandbusinessmodelsthatwouldsupporteitherbiofuelsorelectricity-derivedfuelsatmulti-EJscaledonotexistineithercountry.On-roadpassengerandfreighttransport.ElectrificationislikelytobethedominanttechnologyforreducingCO2frompassengertransport,whiletechnologystrategiesforfreightarelikelytobemoremixed.AlthoughEVsarenowclosertolifecyclecostparitywithICEvehicles,costandconvenienceconcernsandthelackofamoreextensivechargingnetworkstillhampermorewidespreadadoptionofEVs.Someformofadditionalpolicypushisneededinbothcountriestoreacha50%ZEVmilestoneby2030,thoughinnovationandincreasesinmanufacturingscaleneededtomeetthismilestonewouldsignificantlydrivedownEVcosts.TheUnitedStatesdoesnotyethavenationalpoliciesorregulationsforencouragingthemanufacturinganddeploymentoffreightZEVs,thoughCalifornia’sAdvancedCleanTruckProgramisanexampleofastate-levelinitiativethatcouldserveasamodelfornationalpolicy.China’sMinistryofFinancehasofferedsubsidiesforheavy-duty“newenergyvehicles”since2015,butthescaleofpolicyandregulationinChinawouldneedtoincreasedramaticallytomeeta30%ZEVsalesmilestoneforon-roadfreighttransportby2030.45Buildings.ElectrificationandimprovementsinbuildingshellefficiencyarelikelytobedominantstrategiesforreducingCO2emissionfrombuildings.Implementingthesestrategiesinnewandexistingbuildingswillposedifferentchallenges.Innewbuildings,electricspaceandwaterheatingmaybecost-effectiveinsomeclimatesbutRD&Disneededtoaddresstheheatpumpperformancechallengesandelectricdistributionrequirementsincolderweatherclimates.Forexistingbuildings,innovationsinpolicy,diagnostictools,andretrofitstrategiesareneededtoreducecosts.InChina,anadditionalchallengewillbetheroleofelectrificationversusdistrictheatingsystems.Greaterelectrificationandbuildingsandtransportationinbothcountrieswill42Forinstance,California’selectricitygenerationpoliciestarget60%cleanenergyby2030and100%by2045anNewYork’starget70%renewablesby2030and100%zeroemissionselectricityby2040.Bothofthesetargetsarebackedbyexistinganexistingregulatoryframework,thoughNewYork’sisnotbinding.Foranoverview,seetheNationalConferenceofStateLegislatures,“StateRenewablePortfolioStandardsandGoals,”https://www.ncsl.org/research/energy/renewable-portfolio-standards.aspx.ChinahasnationalgoalsforTW-scalesolarandwinddevelopmentbutdoesnotyethaveapolicyorregulatoryframeworktoimplementthesegoals.43See,forinstance,E3(2018)andSepulvedaetal.(2018).44See,forinstance,Williamsetal.(2021)andLarsonetal.(2020).45SeeMinistryofFinance,2015,NoticeonFinancialSupportforEncouragingAdoptionofNewEnergyVehicles2016-2020(关于2016-2020年新能源汽车推广应用财政支持政策的通知),http://fgk.mof.gov.cn/law/getOneLawInfoAction.do?law_id=83837.28requirethoughtfulconsiderationofhowtomanagethereliability,resilience,andsecurityneedsofmoreelectricenergysystems.Industry.IndustrialCO2emissionsareheterogeneousbutaredominatedbyafewkeysectors.IntheUnitedStates,refining,chemicals,andironandsteelproductionaccountforabout65%ofenergy-relatedCO2emissionsfromindustry.46InChina,ironandsteel,non-metallicproducts(mostlycement),andchemicalsaccountforabout75%ofenergy-relatedCO2emissionsfromindustry.47Thissuggeststhat,whiletechnologystrategiesforreducingCO2emissionsinindustrymaybesectorspecific,keysectorsoffocusthatarecommontotheUnitedStatesandChinawouldincludethesteel,chemicals,andcementindustries.ThesesectorsdonotyethaveclearpathwaysforreducingGHGemissionsandrequireRD&D.Inadditiontoamoresector-specificfocus,theremayalsobecross-cuttingstrategies,suchasefficiencyimprovementsformotors,processheatingsystems,andsteamsystems,thatwarrantattentionandRD&D.Acrosssectors,itisstillunclearwhattherightmixofincentivesandregulationwillbeforencouragingthedevelopmentandadoptionofnewtechnologies.Forinternationallytradedproducts,thischallengeiscompoundedbythedesireofgovernmentstoavoidreducingthecompetitivenessofdomesticmanufacturing.Forestryandagriculture.TherearebroadlytwostrategiesforincreasingCO2sequestrationinforestryandagriculture:(1)nationalprograms,whichoftenpaylandownersforconservation,and(2)offsetsincap-and-tradeprograms,whichpaylandownersforsequesteringCO2permanentlyoratleastoverlongperiodsoftime.Theformeristypicallytaxpayerfundedandissubjecttotheavailabilityoffunding,thoughbothcountrieshavehistoricallyhadlargenationalconservationprograms.Thelattermayhaveareadysourceoffunding,throughcap-and-tradesystems,butrequiresmonitoring,verification,andenforcementmechanismstoensurethatpaymentsleadtoCO2sequestration.NeithertheUnitedStatesnorChinahavethemethodologiesorinstitutionstorunrigorousoffsetprogramsatmillionmegatontogigatonCO2peryearscale.Geologicalsink.TechnologiesforcapturingandgeologicallysequesteringCO2areincreasinglymature,butgeologicalCO2sequestrationlacksbothabusinessmodelandamodelforinternationalgovernanceoftheCO2sink.WhileothermeasuresformitigatingCO2canbejustifiedintermsofdomesticbenefits—airqualityimprovements,publichealth,technologyinnovation,landconservation—theonlybenefitofgeologicalCO2sequestrationislowerglobalCO2emissions,whichmeansthataneffectivesystemofinternationalgovernancewillbeneededtoverifyandmonitorsequesteredamounts,withmechanismstoencouragecompliance.3.6AreasforU.S.-ChinaCoordinationTheabovesectionsillustratethatmanyofthehigh-leveltechnologyandpolicystrategiesforachievingcarbonneutralitywillbecommontoboththeUnitedStatesandChina.WhatdoesthisimplyforU.S.-Chinacoordinationoncarbonneutrality?Weidentifyfourmainformsofcoordination:1)Commonmilestones,whichwouldseektodevelopcommonmeasuresofprogresstowardmid-centurycarbonneutralitygoals,withthegoalofcreatinglargermarketsthatspurinnovationandreducetechnologycosts.2)Dialogueandtechnicalexchange,whichwouldestablishregulardialogueandtechnicalexchangeontopicswherethetwocountriesfacesimilarchallengesandwherediscussioncouldhelptopromoteconvergenceintechnologystrategies.46DataarefromEIA(2020).47BasedonWangetal.(2019).293)RD&Dprioritization,whichwouldseektoidentifycommonorcomplementarypriorityareasforRD&D,tofocusandincreasethescaleofRD&Defforts,encouragehealthycompetition,andenhancethechancesofbreakthroughtechnologies.4)Internationalleadership,whichfocusesonadvancingU.S.-Chinagloballeadershipontechnologyandgovernanceissues.Foreachofthesefourforms,Table8describespotentialfocusareas.Fordialogueandtechnicalexchange,thesefocusareasarekeyquestions;forRD&Dprioritization,theyarekeytechnologyareas;forinternationalleadership,theyareareaswheretheUnitedStatesandChinacanexertcoordinatedleadership.CoordinationaroundthesefourareascouldoccurthroughaU.S.-ChinaCarbonNeutralityWorkingGroup,whichwouldbeanaturalsuccessortotheU.S.-ChinaClimateChangeWorkingGroup.ThisCarbonNeutralityWorkingGroupcouldhavenationalandsubnationaltracks,inrecognitionofthecomparativestrengthsofU.S.andChineseclimatepolicy:China’snationalclimatepolicyinitiativehasbeenearlierandstrongerthantheUnitedStates’,whereas,becauseofalackofnationalleadership,U.S.subnationalgoalsetting,planning,andpolicydevelopmentformeetinglong-termGHGemissionreductiontargetshavebeenstrongerthaninChina.CreatingspaceforsubnationaldialogueandtechnicalexchangeunderaWorkingGroupwouldenableU.S.statesandcitiestosupportthedevelopmentofsubnationalplanningandpolicymakingcapacityinChinaandwouldprovideaforumforsharingimplementationexperience.AsubnationalcomponenttoU.S.-Chinacoordinationaroundcarbonneutralityalsorecognizesthat,fortheUnitedStatesandChinatoachievemid-centurygoals,somestates-provincesandcitieswillneedtoleadbyachievingcarbonneutralityaheadofnationaltargets.SubnationalinitiativesunderaU.S.-ChinaCarbonNeutralityWorkingGroupcouldthusfocusonsettinggoalsandmilestonesthatmayexceedthoseatanationallevel.30COLLABORATIONFORMSFOCUSAREASCommonMilestonesDevelopingcommonandspecificmilestonesfor2030,2040,and2050-2060,alongthelinesofthemilestonesproposedinthisreport,andsharinginformationoneffectivepoliciesandprogramsforachievingmilestonesDialogueandTechnicalExchangeMedium-andlong-termplanning.Whatarepotentialtechnologypathwaystoachievingcarbonneutralitygoalsandwhatarethekeypolicyandtechnologypathwaysalongdifferentpathways?Finance.Howcanthefinancialindustrysupportthetransitiontolowercarbonenergysystemsandmoresustainableagriculture,forestry,andwastemanagementsystems?Justtransition.Howcangovernmentssupportthetransitiontocarbonneutraleconomieswhileatthesametimereducinginequality?Renewableelectricitysystems.Howcanelectricitysystemsbeoperatedcost-effectivelyandreliablywithmuchhigherpenetrationsofsolarandwindgeneration?Low-carbonfuels.Whatarepotentialregulatoryandbusinessmodelsthatcansupportanindustryforlow-carbonfuels—biofuels,hydrogen,andsyntheticfuels?Howcanthesustainabilityandfoodsecurityconcernsaroundbiofuelsbeaddressed?Zeroemissionvehicles.Whatpolicyandregulatorymeasurescansupportthescalingupinmanufacturingandadoptionneededtoelectrifypassengertransport?Whatarepotentialregulatorymodelsforencouragingzeroemissionvehiclesinfreighttransport?Zeroemissionbuildings.Whatpolicyandregulatorymeasurescansupportelectrificationandbuildingshellefficiencyimprovementsfornewandexistingbuildings?Industrydecarbonization.WhatarethetechnologiesandpotentialpolicyandregulatorymeasurestoencourageCO2reductionsinindustry,focusingonthesteel,cement,andchemicalssectorsandcross-cuttingtechnologiesinothersectors?Forestryandagriculturalextension.Whatmanagementandextensionpracticescanpromoteforestandagriculturalsoilcarbonsequestrationonalargescale,andhowcansequestrationbefunded,monitored,andverified?Non-CO2GHGmitigation.Whattechnologiesandregulatoryapproachescanreducemethaneemissionsinenergysystemsandmethaneandnitrousoxideemissionsinagriculture?Whatregulatoryapproachescansupportalternativestohydrofluorocarbons(HFCs)?RD&DPrioritizationReliablezeroemissionenergyandlong-durationstoragetechnologies,whichwouldfacilitatelow-cost,reliable100%renewableelectricitysystemsAdvancedbiofuels,whichwouldreducethelanduseimpactsandfoodsecurityconcernswithbiofuelsScalablebuildingretrofittechnologiesandtools,whichwouldreducethecostsofelectrifyingorimprovingbuildingshellefficiencyinexistingbuildingsLowemissionstechnologiesforindustry,whichwouldprovidelow-costtechnologyoptionsforreducingCO2emissionsinthesteel,cement,andchemicalsectorsandforothercross-cuttingtechnologiesInternationalLeadershipInternationalshippingandaviation.LeadershipininternationalorganizationsthatcreatesapathtozeroemissionsshipsandplanesTechnologytransfer.IncorporatingCO2emissionsstandardsintoguidelinesforinternationaldevelopmentaidCO2sinkgovernance.Developmentofinternationalinstitutionstomonitor,verify,andenforceCO2sequestrationTable8PotentialFocusAreasforU.S.-ChinaCoordinationonCarbonNeutrality31CHAPTERFOURCONCLUSIONSMomentumfromrecentnationalcarbonneutralitycommitmentsiscreatingawindowofopportunityformakingmeaningfulprogressagainstthetemperaturetargetsratifiedintheParisAgreement.TheUnitedStatesandChinawillbeprimemoversineffortstogettonetzeroemissionsgloballybyaroundmid-century,buttheirbilateralrelationshipwillbeequallycritical.Giventhescaleandscopeofthetransitionchallenge,neithercountrywillbeabletoachievethesegoalsinisolation.AlthoughrecentattentionhasfocusedondifferencesbetweentheUnitedStatesandChina,thethreereportsinthisserieshighlightthatthereisasignificantamountofconvergenceintechnologypathwaystoachievecarbonneutralitybetweenthetwocountries.Overall,strategiesforachievingcarbonneutralityareexpectedtobesimilar.Thisconvergenceistheresultofcommontechnologies,afundamentallyinterconnectedworld,andphysicalresourcelimits.Convergencesuggeststhat,thoughchallengesintheU.S.-Chinabilateralrelationshipmaylimitthedepthoftheircollaboration,thereishighvaluetocoordination.Coordinationdoesnotrequirejointandverifiablecommitmentsorresolvingdifferencesasaprecondition.Atitssimplest,coordinationonlyrequiresasharedunderstandingofthepaceanddirectionoftechnologytransition.AnimportantformofU.S.-Chinacoordinationwillbearoundsettingintermediateandlong-termsectoralmilestonesforachievingcarbonneutrality.Unlikenationalcommitments,milestonesarenon-bindingmeasuresofprogresstowardlonger-termgoals.Theycanbedesignedtocapturekeysectortransitions—suchastheshifttowardnon-fossilgenerationintheelectricitysectorortheshifttonon-internalcombustionenginevehiclesintransportationsector—inwaysthatarereadilymeasurableandprovideameaningfulreferenceforpolicymaking.IftheUnitedStatesandChinacandevelopcommonandcrediblemilestones,asproposedinthisreport,thiswouldprovideasimple,powerfulsignalonthepaceanddirectionofexpectedtechnologychange,bothdomesticallyandinternationally.Coordinatedmilestonescouldspurthetechnologicalinnovationandcostreductionsthatwillbepracticallyneededforsuccess.Milestoneswouldalsofillanimportantgapbetweenlong-termgoalsandthenearer-termtransitionsrequiredtoachievethem.Althoughtherehasrecentlybeenagrowingfocusinbothcountriesonthechangesintechnologiesrequiredtomeetmid-centurycarbonneutralitygoals,therehasbeenlessfocusonwhatlong-termstudiesimplyforneededactionsoverthenextdecade.Thisisanimportantoversight.Inmanyways,thechallengesofbuildingmomentumandre-orientingcapitalandpoliticaleconomyacrosstheenergy,buildings,industrial,andtransportationsectorswillbelargeroverthenextdecadethantheywillinsubsequentdecades.Insetting2030and2040milestones,itisimportanttoworkbackwardfrommid-centurygoalsratherthanfocusingonincrementalchangefrom2020,intermsofthinkingaboutfeasibility.Thescaleof2030milestonesmayseemdaunting,butlowereffortinthenextdecade(a2030milestone)willmeansignificantlymoreeffortinthefollowingdecade(a2040milestone).Inessence,workingbackwardfroma2050-2060goalofnetzeroemissionswillraisethetrajectoryofrequiredintermediatemilestones.Milestonescanbeadaptedovertimeastechnologieschange.Indeed,thetechnologiesof2050—energy,vehicle,building,industrial,wastemanagement,agricultural,forestry—willlikelybeverydifferentthanthoseoftoday.Thenecessarystepsforwardoverthenextdecadetomeet32mid-centuryemissionstargets,however,arerelativelyclear.Theyincludeasignificantscaling-upofrenewableenergytodecarbonizeelectricitysystems,rapidgrowthinEVandheatpumpadoption,landusepoliciesthatsupportCO2sequestration,methanecontrolsinenergysystems,andinitialeffortstodeveloplow-carbonfuelsandreduceCO2emissionsinindustry.Moreambitiouseffortsoverthenextdecadecouldreducetheneedforexpensiveorinstitutionallychallengingsolutions,suchasdirectaircaptureandsequestrationofCO2,inthelongerterm.Thissuggestsnewwaysofconsideringtheinsurancevalueprovidedbypolicy-driveneffortstolowerenergydemandthroughconservationandend-useefficiency.Greaternearer-termambitionwouldalsohelptobuydownthecostsofreducingGHGemissionsinmiddle-incomecountries,whichwillaccountformostglobalemissionsgrowthoverthecomingdecades.Althoughmostofthedeepdecarbonizationandcarbonneutralitystudieswereviewedinthisseriesarebasedonexistingtechnologies,RD&Dthatimprovesuponexistingtechnologiesorenablesnewtechnologieswillbecriticalforreducingcostsoraddressingphysicalchallenges.Forbothcountries,themostcriticalRD&Dproblemisindevelopingadditionallow-costreliablegenerationandlong-durationstoragetechnologiesforfirmingrenewableelectricitysystems.BydevelopingasharedunderstandingofRD&Dpriorities,focusingoncommonorcomplementaryproblems,andatleastpublishingresults,theUnitedStatesandChinawillbeabletoachievefarmorethaneithercountrycouldinsoinisolation.TheremarkablecostreductionsandglobalgrowthofsolarPVtechnologiesoverthepastdecadeunderscoretheupsideofparallel,coordinatedRD&DandthefactthataglobalRD&Deffortdoesnotrequirecentralizedmanagement.ThefocusinthisreportwasmorenarrowlyonCO2emissions,butthereareamplereasonstoextendU.S.-ChinacoordinationtoGHGemissionsmorebroadly,particularlyfordialogue,technicalexchange,andRD&D.Reductionsinmethane,nitrousoxide,andhydrofluorocarbon(HFC)emissionscouldreducetheneedfornegativeemissionstechnologiesoverthenextfourdecades.Tocoordinateeffectively,theUnitedStatesandChinawillneedtoreconstitutebutalsoreimaginetheClimateChangeWorkingGroupthatfacilitatedtheirclimate-relateddialogueandnegotiationsfrom2013to2017.Thesuccessorproposedhere,aU.S.-ChinaCarbonNeutralityWorkingGroup,wouldincludeparticipationofsubnationalgovernmentsinrecognitionofthetwocountries’comparativestrengthsoftheUnitedStatesandChina.InclusionofasubnationalfocusintheWorkingGroupwouldalsoprovidespaceforleadingstates-provincesandcitiestodevelopcommitmentsandmilestonesthatexceednationalambition.33CHAPTERFIVEAPPENDIXA:DOCUMENTATIONOFCALCULATIONS5.1GeneralCalculationsTheestimatesinthemilestonesectionrelyonahigh-levelmodelthatdrawsoninputsfromtheU.S.andChinareviews.Thisappendixprovidesadetaileddescriptionofthemodelandcalculationsinthemaintext.Themodelseparatesfinalenergyconsumptionintoelectricityandfuels.Finalelectricityconsumptioninyeary(EFy)iscalculatedasfinalenergyconsumptioninyeary(FEy)multipliedbytheeconomywideelectrificationrate(αy)Fuelsarenon-electricsolid,liquid,andgaseousformsoffinalenergyconsumption.Finalfuelsconsumptioninyeary(FFy)iscalculatedasfinalenergyconsumptioninyeary(FEy)multipliedbyoneminustheeconomywideelectrificationrateinyeary(αy)Someportionoffuelsconsumptionwillbeintheformofelectricityderivedfuels.Theamountofelectricityconsumedinfinalfuelsconsumptioninyeary(EFLy)willbefinalfuelsconsumptioninyeary,multipliedbytheshareofzeroemissionfuelsinthatyear(βy),multipliedbytheshareofelectricityinzeroemissionfuels(θy)Theportionofzeroemissionfuelsthatarenotelectricfuelsareassumedtobefinalbiofuels(BFLy)Primarybiofuelsconsumptioninyeary(PBy)isfinalbiofuelsconsumptioninyeary(BFLy)dividedbyaconversionrate(ρ)Themodelcalculatestotalelectricitygenerationinyeary(EGy)asthesumoffinalelectricityconsumptioninyeary(EFy)andfinalelectricfuelsinyeary(EFLy)dividedbyanelectricity-to-fuelconversionrate(μ),dividedbyoneminustransmissionanddistribution(T&D)losses(γ).EGyinEJunitsisconvertedtoTWhbydividingby3.6andmultiplyingby1,000.34ThisapproachassumesthatelectricfuelshavethesameT&Dlossesasdirectelectricityconsumption,whichlikelyoverestimateselectricitygenerationaselectricfuelproductionmaybeinterconnectedatsub-transmissionandtransmissionvoltages.Totalnon-fossilgenerationinyeary(NFGy)iscalculatedastotalgenerationmultipliedbytheshareofnon-fossilgenerationinyeary(σy)Table9showstheinputvaluesusedforcalculationsinthemaintextandTable10showscalculatedparametervalues.VARIABLESYMBOLVALUESUNITEDSTATESCHINA203020402050203020402050Finalenergyconsumption(EJ)FEy6357511019283Electrificationrateαy30%40%50%35%45%60%Shareofzeroemissionfuelsβy5%30%80%5%30%80%Shareofelectricfuelsθy50%60%70%50%60%70%Electricfuelsconversionrateρ50%50%50%50%50%50%Biofuelsconversionrateμ50%50%50%50%50%50%T&Dlossesγ7%7%7%7%7%7%Shareofnon-fossilgenerationσy50%70%100%50%70%100%Notesandsources:U.S.finalenergyconsumptionandelectrificationratevaluesfor2050arefromWilliamsetal.(2021);2030and2040valuesarelinearinterpolationsbetweenthe2020and2050valuesinWilliamsetal.(2021).Chinafinalenergyconsumptionvaluesfor2030and2050arefromLBNL(2020);the2040valueisalinearinterpolationbetweentheLBNL2030and2050values.ElectrificationrateforChinain2050isbasedontherangeofestimatesinKhannaetal.(2021);2030and2040valuesareinterpolatedusinga25%electrificationratein2020,basedonIEA(2019a).Theshareofelectricfuelsin2030isbasedonWilliamsetal.(2021)andincreasesovertimeassuminglimitstobiofuelsupplies.Electricfuelsandbiofuelsconversionratesaremiddle-of-the-roadapproximationsbasedonWilliamsetal.(2021).T&Dlossesarebasedonrule-of-thumbvaluesintheUnitedStates.Sharesofzeroemissionfuelsandnon-fossilfuelgenerationarebasedonmilestones.PARAMETERSYMBOLVALUESUNITEDSTATESCHINA203020402050203020402050Finalelectricityconsumption(EJ)FEy192326354150Finalfuelsconsumption(EJ)FFy443426665133Electricfuelsconsumption(EJ)EFLy16142919Biofuelsconsumption(EJ)BFLy146268Primarybiofuelsupply(EJ)PBy281231216Netelectricitygeneration(TWh)EGy6,30410,48716,14711,53917,80625,981Non-fossilgeneration(TWh)NFGy3,1527,34116,1475,76912,46525,981Table9InputValuesUsedforCalculationsintheMainTextTable10CalculatedParameterValues355.2WindandSolarGenerationCalculationsWeusedifferentassumptionstocalculatetheamountofwindandsolargenerationfortheUnitedStatesandChinathatwouldresultfroma50%non-fossilgenerationmilestonein2030(Table11).FortheUnitedStates,weassumethatallincrementalnon-fossilgenerationcomesfromsolarandwindgeneration,duetothelimitedavailabilityofnewhydropowerresourcesandlimitsonthescalabilityofnuclearpowerintheUnitedStates.ForChina,weassumethathydropowercanprovideanadditional100TWh(25-30GW)from2020to2030,consistentwith2030forecastsinIEA(2019a)and2050hydropowergenerationinHe(2020)andtakingChina’stotalhydropowergenerationcapacitycloseto400GWby2030.48Weassumethatnuclearcanprovideanadditional300TWh(~40GW)from2020to2030,whichisconsistentwith2050projectionsbyHe(2020)andequivalenttobuildingapproximately80%ofChina’scurrentnucleargenerationcapacity(49GW)overthenextdecade.495.3IndustrialCO2IntensityCalculationsWeestimatethepercentagereductioninindustrialCO2intensitytomeeta15%industrialCO2emissionreductionmilestoneby2030using48ThehydropowerdataandcapacityfactorsusedintheseestimatesarebasedonCEC(2021)data.49Ibid.UNITEDSTATESCHINANon-fossilgenerationin2019/2020(TWh)1,5722,449Non-fossilgenerationin2030(TWh)3,1525,769Newhydroandnucleargeneration,2020-2030(TWh)0400Newwindandsolargeneration,2020-2030(TWh)1,6532,920Windgeneration/(wind+solargeneration)60%60%Windcapacityfactor(%)0.350.25Solarcapacityfactor(%)0.250.15Windgenerationcapacityin2030(GW)402999Solargenerationcapacityin2030(GW)3751,111Totalwindandsolarcapacityin2030(GW)7772,110Totalwindandsolarcapacityin2020(GW)165535Notesandsources:Non-fossilgenerationandcapacityintheUnitedStates(2019)andChina(2020)arefromEIA(2021)andChinaElectricityCouncil(CEC)(2021),respectively.Windshareofwindandsolargenerationisaroughestimate,basedonitsshareinChinain2020(64%)(CEC,2021)andthe69%2050shareinWilliamsetal.(2021).SolarandwindcapacityfactorsfortheUnitedStatesarebasedonEIA(2021)andforChinaarebasedonCEC(2021).Table11AssumptionsandProjectionsfor2030SolarandWindGenerationandInstalled36WhereCIisthepercentagechangeinindustrialCO2intensity,CEisCO2emissions,VAisindustrialvalueadded,αistheindustrialCO2emissionreductionmilestone,ristheannualaveragerateofrealGDPgrowth,Tandtaretheinitialandfinalperiods,andβistheshareofindustrialvalueaddedintotalvalueadded(GDP).ForChina,weuseanannualaveragerealgrowthrateof5%peryearfrom2020to2030.BasedonWorldBankdata,theshareofrealindustrialvalueaddedinrealGDPin2019inChinawas0.45;ifthisvalueweretofallto0.35by2030,comparabletowhatitwasintheearly1990s,thepercentagereductioninindustrialCO2intensitywouldbe33%.50Ifthisvalueweretofallto0.40by2040,thepercentagereductionwouldbe41%.ThisillustratestheroleofstructuralchangeinreducingindustrialCO2emissionsinChina.FortheUnitedStates,weuseanannualaveragerealgrowthrateof2.5%peryearfrom2020to2030.BasedonWorldBankdata,theshareofrealindustrialvalueaddedinrealGDPin2019intheUnitedStateswas0.19;ifthisvalueweretoholdsteadyto2030,thepercentagereductioninindustrialCO2intensitywouldbe34%.5150DataarefromWorldBankWorldDevelopmentIndicators,https://databank.worldbank.org/.Theshareofindustrialvalueaddedhereisrealindustrialvalueadded(2010$)dividedbyrealGDP.51Ibid.37CHAPTERSIXREFERENCESChinaAssociationofAutomotiveManufacturers(CAAM).(MultipleYears).VehicleIndustryEconomicOverview(汽车工业经济运行情况),ChinaAssociationofAutomotiveManufacturers,http://www.caam.org.cn/chn/21.html.ChinaElectricityCouncil(CEC).(2021).NationalElectricityStatisticsBrieffor2020(2020国电力工业统计快报一览表),ChinaElectricityCouncil,https://www.cec.org.cn/upload/1/editor/1611623903447.pdf.EnergyandEnvironmentalEconomics(E3).(2018).DeepDecarbonizationinaHighRenewablesFuture.CaliforniaEnergyCommissionReport,CEC-500-2018-012,https://efiling.energy.ca.gov/GetDocument.aspx?tn=223785.Fu,S.,DuX.,Clarke,L.,andYu,S.(2020).China’sNewGrowthPathway:Fromthe14thFiveYearPlantoCarbonNeutrality.Beijing:EnergyFoundationChina,https://www.efchina.org/Reports-en/report-lceg-20201210-en.He,J.(2020).ChinaLow-carbonDevelopmentandTransitionPathwaysResearch:OverviewofProjectResults.(中国低碳发展战略与转型路径介绍:项目成果介绍).Jiang,K.,He,C.,Dai,H.,Liu,J.,Xu,X.(2018),“EmissionscenarioanalysisforChinaundertheglobal1.5°Ctarget,”CarbonManagement9(5):481-491,https://doi.org/10.1080/17583004.2018.1477835.InternationalEnergyAgency.(2019a).WorldEnergyOutlook2019,InternationalEnergyAgency,https://www.iea.org/reports/world-energy-outlook-2019.InternationalEnergyAgency.(2019b).GlobalEVOutlook2019,InternationalEnergyAgency,https://www.iea.org/reports/global-ev-outlook-2019.InternationalEnergyAgency(IEA).(2020a).SolarPVmodulemanufacturinganddemand,2014-2020,InternationalEnergyAgency,https://www.iea.org/data-and-statistics/charts/solar-pv-module-manufacturing-and-demand-2014-2020.InternationalEnergyAgency(IEA).(2020b).Renewables2020:AnalysisandForecaststo2025,InternationalEnergyAgency,https://www.iea.org/reports/renewables-2020/wind.IPCC,2018:SummaryforPolicymakers.In:GlobalWarmingof1.5°C.AnIPCCSpecialReportontheimpactsofglobalwarmingof1.5°Cabovepre-industriallevelsandrelatedglobalgreenhousegasemissionpathways,inthecontextofstrengtheningtheglobalresponsetothethreatofclimatechange,sustainabledevelopment,andeffortstoeradicatepoverty[Masson-Delmotte,V.,P.Zhai,H.-O.Pörtner,D.Roberts,J.Skea,P.R.Shukla,A.Pirani,W.Moufouma-Okia,C.Péan,R.Pidcock,S.Connors,J.B.R.Matthews,Y.Che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