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NaturalResourcesDefenseCouncil Embodiedcarbonreductionroadmap StrategiesandpoliciesforthestateofCalifornia September2023 Contents Executivesummary4 1Embodiedcarbonreductionroadmap6 2Embodiedcarbonreductionstrategies12 2.1Optimizeproject13 2.2Optimizesystems14 2.3Optimizeprocurement16 2.4Optimizeconstruction20 3Embodiedcarbonpolicies22 3.1Planning24 3.2Buildingcodes25 3.3Cleanprocurement29 3.4Waste&circularity30 3.5Climatecommitment31 3.6Training&education32 4Conclusionandrecommendations35 AppendixA36 AppendixB41 AppendixC51 NaturalResourcesDefenseCouncil|EmbodiedcarbonreductionroadmapArup2 Executivesummary Executivesummary Thecarbonemissionsassociatedwithmaterialsusedinthebuiltenvironment,referredtoas“embodiedcarbon,”areestimatedtocontributeto11%ofallglobalenergy-relatedcarbonemissions.1Whilecurrentlythisfigureislessthanthe28%ofglobalcarbonemissionsattributedtobuildingenergy use,itisestimatedthat,duetotherapidgrowthofnewconstructionneededtomeetthedemandofgrowingpopulations,nearlyhalfofthetotalcarbonemissionsfromnewconstructionfromnowuntil2050willbeattributabletotheembodiedcarbonofourbuiltenvironment.2 Whiletherehasbeenextensivefocusonpoliciesaddressingdecarbonizationofindustrialmaterialsandseparatelyonaddressingenergyuseinbuildings,thesepoliciesreducematerialproductionemissionsandoperationalemissions.Additionalpoliciesareneededtoreducethebalanceofwholebuildingemissionsaffectedbydesignandconstructionpractices.Thegoalofthisstudywastofullysynthesizethebroadertechnologyandpolicylandscaperelevanttoembodiedcarboninbuildings. ThestudychosetofocusonthestateofCaliforniaandlocalgovernmentswithinthestate,whichallowstheassessmenttoconsiderfeasibilitymorepracticallyandspecifically.Californiawaschosenduetoitscapacity,leverage,andtrackrecordforloweringbarriersandrisksforothersinthenationandaroundtheworld. Surelyenough,legislativemovementaroundembodiedcarboninCaliforniaisrapidlydeveloping.AssemblyBill(AB)2446,signedintolawin2022,directsthedevelopmentofaframeworkformeasuringandreducingtheaveragecarbonintensityofbuildingmaterialswithatargetsetof40%reductionby2035.Meanwhile,thepublicsectorinCaliforniahasshownmarketleadershipinlowcarbonmaterialprocurementthroughthelandmarkbillAB262,knownastheBuyCleanCaliforniaAct.Mostrecently,theCaliforniaBuildingStandardsCommissionvotedunanimouslytoadoptembodiedcarbonrequirementsintothestate’sgreenbuildingcode,knownasCALGreen. Awiderangeofstrategiescanbedeployedtoreduceembodiedcarboninthebuiltenvironment,encouragedbypolicyaction.Thisstudylookedfirstatdifferenttypesofavailablestrategiesandestimatedtherelative proportionofembodiedcarbontheycouldreduce.Thestrategieswerethenmappedagainstdifferenttypesofbuilding-sectorpolicies. Forthefirsttask,Arupquantifiedthereductionpotentialofvariousstrategiesthrough2045,whichisthenetzerotargetdateforthestateofCalifornia.Embodiedcarbonreductionstrategiesinbuildingswerecategorizedasthosethatareimplementedattheprojectscale,buildingsystemscale,orprocurement(material)scale.Strategiestooptimizetheprojectweredeterminedtohave themostreductionpotentialintheshorttermwhilestrategiestooptimizeprocurement(i.e.,material-levelreductions)hadthemostreductionpotentialinthelongterm.Thisisbecausemanyofthetechnologiestodecarbonizematerialproductionareslowertoscale.Incontrast,strategiestooptimizetheprojectthatfocusonbuildinglessormoreefficientlycanbeimplementedimmediately. Basedonevaluatingbotheaseofimplementationandmagnitudeofreductionpotential,policiestakingbothabuilding-focusedapproachandmaterial-focusedapproachwouldleadtothehighestPotentialscale.Moreover,bothabuilding-focusedapproachandmaterial-focusedapproachcanbeeffectivelyintegratedintobuildingcodes.Abuilding-focusedapproachuseswholebuildinglife-cycleassessment toevaluateperformance.Amaterial-focusedapproachusesenvironmentalproductdeclarationstoevaluateperformance.Whileexamplesofbuildingcodeintegrationareprovidedwithinthereport,mid-cyclechangestoCALGreenarealreadyunderway. Inadditiontostatewidecodeupdateefforts,localbuildingcodeauthoritiescanadoptmorestringentrequirements,andlocalplanningauthoritiescandomoretointegrateembodiedcarbonintoplanningrequirementsandzoningincentives.Addressingembodiedcarbonincityclimateactionplans andsupportingindustry-ledinitiativestoeducatepractitionersontheimportanceof,andmethodstoreduce,embodiedcarbonareadditionalleversthatcanhelpcutembodiedcarbon. Thereporthereinprovidesapolicyroadmapanddescribeshowtheresearchteamarrivedatthesespecificrecommendations. 1.WorldGreenBuildingCouncil,BringingEmbodiedCarbonUpfront(WorldGreenBuildingCouncil,September2019). 2.CarbonLeadershipForum,EmbodiedCarbonFactsandFigures,accessedJanuary7,2023,https://carbonleadershipforum.org/wp-content/uploads/2019/11/Embodied-Carbon-Facts-and-Figures.pdf. NaturalResourcesDefenseCouncil|EmbodiedcarbonreductionroadmapArup4 Embodiedcarbonreductionroadmap 1Embodiedcarbonreductionroadmap ArupquantifiedthereductionpotentialofstrategiesexploredwithinthisreportfornewresidentialandcommercialconstructioninCalifornia.Byquantifyingredu