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1、Carbon Accounting for Sustainable BiofuelsThe IEA examines the full spectrum of energy issues including oil,gas and coal supply and demand,renewable energy technologies,electricity markets,energy efficiency,access to energy,demand side management and much more.Through its work,the IEA advocates poli

2、cies that will enhance the reliability,affordability and sustainability of energy in its 31 member countries,13 association countries and beyond.This publication and any map included herein are without prejudice to the status of or sovereignty over any territory,to the delimitation of international

3、frontiers and boundaries and to the name of any territory,city or area.Source:IEA.International Energy Agency Website:www.iea.orgIEA member countries:AustraliaAustriaBelgiumCanadaCzech RepublicDenmarkEstoniaFinlandFranceGermanyGreeceHungaryIrelandItalyJapanKoreaLithuaniaLuxembourgMexicoNetherlandsNe

4、w ZealandNorwayPolandPortugalSlovak RepublicSpainSwedenSwitzerlandRepublic of TrkiyeUnited KingdomUnited StatesThe European Commission also participates in the work of the IEAIEA association countries:Argentina BrazilChinaEgyptIndiaIndonesiaKenyaMoroccoSenegalSingapore South Africa Thailand UkraineI

5、NTERNATIONAL ENERGYAGENCYCarbon Accounting for Sustainable Biofuels Abstract PAGE|3 I EA.CC BY 4.0.Abstract The development of sustainable biofuels is at a pivotal juncture.They are recognised for their important role in decarbonising the transport sector particularly for their potential to help red

6、uce aviation and shipping emissions,and for their complementarity with EVs and energy efficiency measures in road transport.However,large-scale deployment of biofuels also raises concerns.The perceived climate benefit of biofuels depends largely on the carbon intensity of their supply.Thus,sound reg

7、ulatory frameworks supported by transparent,science-based carbon intensity calculations will be required to attract the investments needed to scale up biofuel production.Using carbon accounting for policymaking purposes is further complicated by mixed reports on biofuel GHG emission results and the

8、lack of consensus across methodologies.The present study,prepared in support of Brazils G20 presidency,examines such complexities and discusses regulatory approaches for accounting biofuel carbon intensity across various regions.It highlights the main reasons for variability of lifecycle GHG emissio

9、ns of biofuels and emphasises that impacts of land use change are a major source of disagreement across different policy frameworks.It concludes that policies need to adopt pragmatic approaches to foster verifiable and performance-based continuous improvement of sustainable biofuels.Carbon Accountin

10、g for Sustainable Biofuels Acknowledgements PAGE|4 I EA.CC BY 4.0.Acknowledgements The Carbon accounting for sustainable biofuels report was prepared by the Renewable Energy Division of the Directorate of Energy Markets and Security of the International Energy Agency.The study was designed and direc

11、ted by Paolo Frankl,Head of the Renewable Energy Division.The lead authors were Ana Alcalde Bscones,who also coordinated the report production,and Ilkka Hannula.Other authors were Jeremy Moorhouse and Toril Bosoni(Head of the Oil Market Division).The report benefitted from major analytical contribut

12、ion of external LCA-expert consultants Stefan Majer and Sophia Bothe from DBFZ,the German Institute for Biomass Research.We also thank Christiane Henning and Katja Oehmichen from DBFZ for their support.The report fed extensively on discussions and feedback gathered at an IEA workshop on Sustainable

13、Biofuels held in Paris,France(April 2024),and several events organised by the CEM Biofuture Platform Initiative at the 3rd meeting of the G20 Energy Transitions Working Group in Belo Horizonte,Brazil(May 2024).Special thanks go to the members of the Biofuture Platform Initiative Jim Spaeth(DOE/Chair

14、 of Biofuture Platform Initiative),Keith Kline(Oak Ridge National Laboratory)and Gerard Ostheimer(Manager,CEM Biofuture Campaign).Valuable comments and feedback were provided by senior management and colleagues within the IEA,including Keisuke Sadamori,Timur Gl,Uwe Remme,Elizabeth Connelly and Shane

15、 McDonagh.Many experts from outside of the IEA provided valuable input,commented and reviewed this report.They include:Countries Brazil(Las de Souza Garcia,Head of the Renewable Energy Division Ministry of External Relations,Marlon Arraes Jardim Leal,Director of Biofuels Ministry of Mines and Energy

16、,Heloisa Borges Esteves,Director of Oil,Gas and Biofuel Studies EPE,Energy Research Company);European Commission(Biljana Kulisic DG Energy),France(Guillaume Boissonnet,Senior Researcher CEA,French Alternative Energies and Atomic Energy Commission);Italy(Giovanni Perrella,Energy Department,Ministry o

17、f Environment and Energy Security);Japan(Masashi Wanatabe and Takashi Hasegawa,Ministry of Economy,Trade and Industry);United Kingdom(Brendan Bayley,Head Climate and Agriculture HM Treasury,Peter Coleman,Head of Bioenergy and Land Use Science,Carbon Accounting for Sustainable Biofuels Acknowledgemen

18、ts PAGE|5 I EA.CC BY 4.0.Department for Energy Security and Net Zero);United States(Jim Spaeth,Program Manager Bioenergy Systems Development&Integration,DOE).Other Organisations Azim Bin Norazim(International Air Transport Association,IATA),David Chiaramonti and Matteo Prussi(Politecnico di Torino),

19、Timo Gerlagh(RVO,Netherlands Enterprise Agency),Uisung Lee and Michael Wang(Argonne National Laboratory),Keith Klein(Oak Ridge National Laboratory),Marcelo Moreira(Agroicone),Renan Novaes(Embrapa,Empresa Brasileira de Pesquisa Agropecuria),Luc Pelkmans(Caprea Sustainable Solutions and Technical Coor

20、dinator at IEA Bioenergy TCP).The CEM Biofuture Campaign brought together comments from industry members.Special thanks to Gerard Ostheimer,manager of the Biofuture Campaign.The Communications and Digital Office provided production support.Particular thanks go to Jethro Mullen and his team:Astrid Du

21、mond,Liv Gaunt,Lorenzo Squillace and Poeli Bojorquez.Kristine Douaud edited the report.This report was developed in close collaboration with the Biofuture Platform,a Clean Energy Ministerial Initiative,for which the IEA acts as facilitator.Carbon Accounting for Sustainable Biofuels Table of contents

22、 PAGE|6 I EA.CC BY 4.0.Table of Contents Executive summary.7 Chapter 1.Introduction.11 Transport fuel demand.11 Tracking biofuel progress.13 Increasing emphasis on GHG emission reduction policies.15 Chapter 2.Policy environment.16 Regulatory approaches.16 Carbon accounting approaches.19 Internationa

23、l collaboration.21 Chapter 3.Carbon intensity calculation.23 Lifecycle carbon intensity of biofuels.23 Methodological decisions.24 Calculation models and tools.25 Land use change evaluation.27 Variability in calculation results.28 Relevance of different parameters on overall carbon intensity.33 Chap

24、ter 4.From lifecycle assessments to policy making.35 GHG emission thresholds.35 Improving GHG performance.36 Uncertainty and impact.40 Chapter 5.Conclusions and policy considerations.43 Methodology and data best practices.43 Policy priorities.44 Stakeholder involvement.46 General annex.48 Parameters

25、 influencing the carbon intensity of biofuels.48 Abbreviations and acronyms.52 Units of measure.52 Carbon Accounting for Sustainable Biofuels Executive summary PAGE|7 I EA.CC BY 4.0.Executive summary Carbon accounting is of increasing importance in biofuel policies around the world.Carbon accounting

26、 is a generic term that refers to the assessment of GHG emissions,based on lifecycle assessment principles,and covers the whole biofuel supply chain and final use.GHG performance is expressed as carbon intensity in grammes of CO-equivalent per megajoule of produced biofuel(gCO-eq/MJ),which includes

27、all gases with global warming potential.Carbon accounting is already considered in policymaking.Road transport,a significant generator of carbon emissions,is a sector where in the coming five years,nearly 40%of fuel demand will be covered by policies incentivising lifecycle carbon reductions,marking

28、 a shift from traditional biofuel blending mandates.The development and use of transparent and internationally agreed GHG accounting is key for the deployment of sustainable biofuels.Sustainable biofuels play an important role in decarbonising transport.They complement the carbon reductions offered

29、by electric vehicles and other energy efficiency measures in road transport and are expected to play an increasing long-term role in aviation and shipping.Sustainable biofuels can also provide benefits in terms of energy security and job creation,including in rural environments.However,large-scale d

30、eployment of biofuels,especially crop-based,raises sustainability concerns in some areas,mainly related to land use,net GHG emission balance,and unintended impacts on biodiversity or food prices.These concerns can undermine the credibility of biofuels as a sustainable option,and in some cases pose a

31、 barrier to investment and trade.Using carbon accounting for policymaking purposes is further complicated by mixed reports on biofuel GHG emission results and the lack of consensus across methodologies.The present study,prepared in support of Brazils G20 presidency,examines such complexities and dis

32、cusses regulatory approaches across regions.The study aims to identify main commonalities and differences between carbon accounting frameworks.It examines the main contributors to biofuel carbon intensity,their impact and the associated level of uncertainty in quantification.The study also reviews p

33、otential interventions to improve biofuel carbon intensity and discusses policy implications and priorities.GHG accounting is handled similarly across most biofuel policy frameworks,except regarding land use change.Results for“core LCA”values(that represent emissions associated with the supply chain

34、,excluding land-use Carbon Accounting for Sustainable Biofuels Executive summary PAGE|8 I EA.CC BY 4.0.change)can vary widely among similar biofuel pathways,but methodologies are robust,and causes are well understood.The three main causes for the wide ranges in core LCA results are related to region

35、al differences,methodological choices,and data input quality and representativeness.While some regional disparities reflect actual practices and local context(e.g.electricity emission intensity or fertiliser consumption),others can be solved by addressing issues resulting from methodological choices

36、(such as co-product handling methods or system boundary setting)or data quality.Impacts of land use change can be considerable and are a major source of disagreement across different policy frameworks.Emissions caused by direct land use change(the conversion from a previous non-cropland category to

37、bioenergy cropland)can be observed and quantified.However,indirect land use change(when bioenergy growth generates an indirect expansion of cropland into high carbon stock land elsewhere)deals with international economic dynamics that need to be modelled and cannot be measured or verified.Indirect l

38、and use change is the main cause of disagreement around biofuels GHG accounting,due to the high uncertainty of results and the risk of arbitrariness when attributing an indirect land use change(iLUC)value to a certain feedstock and biofuel pathway.This calls for alternative policy approaches.Biofuel

39、 carbon intensity can be improved with supportive policy frameworks and appropriate verification procedures.Several aspects of biofuel production can be improved to reduce GHG emissions.For example,in the cultivation process,which is one of the biggest contributors to biofuel supply chain emissions,

40、several innovative solutions have recently started being introduced.These include adopting more sustainable farming practices like multi-cropping,reduced tillage,and low-emission fertilisers.Applying compost,digestate or biochar,can also contribute to the accumulation of soil carbon stock.Emissions

41、can be further reduced by using renewable energy to supply process heat and electricity demand.New technologies such as carbon capture,coupled with biofuels production,can potentially lead to negative GHG emissions values.However,such interventions are likely to increase costs and require market and

42、 policy frameworks that reward biofuel pathways with higher GHG emission reductions,underpinned by measurable and verifiable lifecycle data.Policies need to adopt pragmatic approaches to foster verifiable and performance-based continuous improvement of sustainable biofuels Policies need to enable th

43、e measurement and verification of data for GHG accounting.To achieve this,they should be underpinned by methodology and data best practices that support the use of transparent and consistent Carbon Accounting for Sustainable Biofuels Executive summary PAGE|9 I EA.CC BY 4.0.methodologies.Relevant fra

44、meworks should foster consistent application of system boundaries across different biofuel pathways based on various feedstocks(including wastes and residues),manufacturing processes and coproducts,as well as the fossil fuels they replace.Collection and use of data that correctly reflect actual prac

45、tices and regional conditions should be systematically encouraged.To significantly accelerate the deployment of sustainable biofuels,policies should stimulate upscaling of the best technologies as well as promoting continuous improvement based on up-to-date GHG performance metrics.More specifically,

46、governments should consider:Establishing policies that reward better GHG performance and drive continuous improvement Transparent and consistent GHG accounting,accompanied by robust verification processes as appropriate,should allow policies to differentiate the performance of biofuels and promote c

47、ontinuous GHG emission reductions,regardless of the feedstock or technology.Prioritising support to measures with significant GHG reduction potential that can be quantified with high certainty and fostering additional measures with less certain quantification while ensuring robust verification steps

48、.While some GHG emission reduction impacts are easier to quantify,others present less certainty when quantifying GHG emission reduction.For this second group of measures,robust verification and certification is required to double-check their effective GHG emission reduction.Addressing indirect land

49、use change(iLUC)concerns by adopting risk-based approaches in the near term and striving to develop global land use policies over time.Indirect land use change values cannot be measured or verified,only modelled.In the short term,qualitative risk-based approaches offering the additional possibility

50、of complying with the requirements of low-iLUC-risk are a good alternative option.These can address potential impacts and encourage improvement instead of attempting to quantify indirect emissions in terms of gCO2-eq/MJ for a given biofuel pathway.In the longer term,policies should evolve from model

51、ling impacts to managing the causes of indirect land use change by enforcing everywhere direct land use regulations and supporting improved agricultural land management.Carbon accounting should be part of a broader portfolio of policies encompassing other sustainability criteria and compliance metho

52、ds to minimise undesired impacts.Policies should protect food and water security,monitor and shelter biodiversity,while taking other socioeconomic factors into Carbon Accounting for Sustainable Biofuels Executive summary PAGE|10 I EA.CC BY 4.0.account.Biofuel policies would need to be designed to be

53、 flexible during periods of tightness in global agricultural markets,to avoid amplifying the size or duration of agricultural price spikes.Enhanced stakeholder engagement and international cooperation is key for increasing consensus on carbon accounting for sustainable biofuels.This includes further

54、 strengthening active collaboration among international organisations such as the International Civil Aviation Organization(ICAO)and the International Maritime Organization(IMO),fostering cooperation with agriculture policy developers,including biofuels and relevant coproducts in broader policies pr

55、omoting an integrated circular(bio)economy,and encouraging consistent protocols and regulations for carbon accounting in voluntary carbon markets.Carbon Accounting for Sustainable Biofuels Chapter 1.Introduction PAGE|11 I EA.CC BY 4.0.Chapter 1.Introduction Transport fuel demand Global oil demand is

56、 forecast to plateau towards the end of this decade as energy transitions gather pace and transport fuel demand goes into decline(Figure 1.1).Nevertheless,led by continued expansion in air travel and petrochemical feedstock uptake,total oil consumption(excluding biofuels)is forecast to rise to nearl

57、y 102 million barrels per day(mb/d)by 2030,2.6 mb/d above the 2023 level.Some economies,notably the Peoples Republic of China(hereafter“China”)and India,will continue to register growth throughout the forecast period.By contrast,oil demand in advanced economies may have already peaked a result of th

58、e sweeping impact of vehicle efficiency improvements and electrification.Figure 1.1 World oil demand,2017-2030 IEA.CC BY 4.0.Source:IEA(2024),Oil 2024:Analysis and Forecast to 2030.Oil demand from the transport sector is set to decline from 2026 owing to efficiency improvements,rapid hybrid and elec

59、tric vehicle(EV)uptake and increased biofuel use(Figure 1.2).However,the pace of change varies across transport modes and depends on the potential for direct electrification.Global road fuel demand is already plateauing in 2024,and total transport demand is close behind.EV sales are set to remain on

60、 a strong growth trajectory,resulting in significant fuel savings.70 80 90 100 110Oil demand,mb/dBiofuelsPetrochemicalfeedstocksTransport,industrial andotherCarbon Accounting for Sustainable Biofuels Chapter 1.Introduction PAGE|12 I EA.CC BY 4.0.According to the IEAs Global EV Outlook 2024,sales cou

61、ld rise to roughly 17 million in 2024(compared with 14 million in 2023),with nearly one in five new cars sold globally being an EV(battery electric or plug-in hybrid).This ascent is set to persist in the current policy environment,with total sales projected to reach 40 million between 2023 and 2030,

62、when almost one in two new cars will be an EV.This will displace 5.2 mb/d of gasoline and diesel demand by 2030,with further reductions of 4.7 mb/d from greater fuel economy.Additionally,biofuel supply will grow from 3.1 to 3.7 mb/d in the same period.Post-pandemic changes in consumer mobility behav

63、iour(related to remote and hybrid work routines)contribute a further 1 mb/d of transport sector fuel savings.Figure 1.2 Biofuel,EV and fuel efficiency impacts on transport sector fossil fuel demand forecast,2023-2030 IEA.CC BY 4.0.Source:IEA(2024),Oil 2024:Analysis and Forecast to 2030.Fossil fuel d

64、emand for long-distance transport modes such as aviation and shipping,which is less amenable to direct substitution,will continue to grow.However,fuel efficiency improvements are progressively slowing demand gains.For instance,while global flight activity returned to pre-pandemic levels over the cou

65、rse of 2023,current jet fuel/kerosene use remains about 5%below the 2019 value.Consumption is not expected to surpass pre-Covid levels until 2027,with strong underlying demand for air travel counterbalanced by major strides in aircraft fuel efficiency.Similarly,efficiencies related to International

66、Maritime Organization(IMO)regulations are set to gradually erode marine fuel consumption.0 20 40 60 8020232024202520262027202820292030mb/dBiofuelsEfficiency savingsEV savingsTransport sectorfossil fuel demandCarbon Accounting for Sustainable Biofuels Chapter 1.Introduction PAGE|13 I EA.CC BY 4.0.Tra

67、cking biofuel progress Biofuel demand has grown steadily in the past five years to just over 4%of global transport fuel consumption in 2024 on an energy basis.In the IEAs main forecast,based on existing policies and firm projects,demand growth accelerates from the historical rate,with biofuels makin

68、g up more than 5%of global transport fuel demand by 2030.In fact,total biofuel consumption rises 20%from the 2023 level to near 6 exajoules(EJ)(3.7 mb/d)by 2030.Biodiesel and renewable diesel(hydrotreated vegetable oil HVO),blended with diesel,account for 40%of this growth,while ethanol blended with

69、 gasoline makes up 35%and biojet fuel blended with jet fuel comprises the remaining 25%.Most new biofuel demand comes from emerging economies,especially Brazil,Indonesia and India.All three countries have biofuel blending targets,rising transport fuel demand and domestic feedstocks.Ethanol and biodi

70、esel use expand the most in these regions.Although advanced economies(including the European Union EU,the United States,Canada and Japan)are also strengthening their transport policies,volume growth is constrained by factors such as rising EV adoption,vehicle efficiency improvements,high biofuel cos

71、ts and technical limitations.Renewable diesel and biojet fuel are the primary growth segments in these regions.Crops were the main source of biofuel production in 2023 and are expected to support 85%of production by 2030.The share of crops used for ethanol production remains steady between 2023 and

72、2030.By contrast,the share of vegetable oils and residue oils(such as used cooking oil and animal fats)reserved for biodiesel,renewable diesel(HVO)and biojet fuel production is expected to expand considerably by 2030.For instance,residue oils jump from 50%of estimated collectable supply to 80%by 203

73、0.Meanwhile,the use of other feedstocks such as agricultural and forestry residues and municipal solid waste more than doubles to 2030,but accounts for only 1%of biofuel production globally.Using these other feedstocks often requires new processing technologies that are not yet commercially availabl

74、e,or new agricultural practices that are not widely used(e.g.growing conventional crops on marginal land;intercropping;double-cropping;and other approaches that can expand feedstock supplies while avoiding competition with food and feed production).It is also possible to reduce the GHG emissions of

75、existing crops through activities such as reducing fertiliser use(see the Improving GHG Performance section).Additionally,there is potential for much quicker deployment growth if proposed policies are implemented,feedstock sources are diversified,and new technologies are deployed in a timely manner.

76、Under the IEA Announced Pledges Scenario(APS),biofuel demand is 80%higher than in the main case by 2030,while biojet Carbon Accounting for Sustainable Biofuels Chapter 1.Introduction PAGE|14 I EA.CC BY 4.0.fuel consumption is nearly three times higher,assuming that Brazil,India,the United Kingdom an

77、d Singapore implement their planned policies and the United States meets its Sustainable Aviation Fuel Grand Challenge targets(Figure 1.3).From a feedstock and technology perspective,new technologies and practices account for nearly 15%of biofuel demand by 2030 under the APS,compared with just 1%in

78、the main case.Technologies such as alcohol-to-jet fuel could provide a market for ethanol,for which demand will have been reduced by wider EV use and greater vehicle efficiency.Consistent carbon accounting approaches,which would assign a value to GHG emission reductions all along biofuel supply chai

79、ns and award additional merit to technologies with lower lifecycle GHG emission intensities,can support this quicker growth.Figure 1.3 Biofuel production by feedstock:Current,main case,Announced Pledges Scenario and Net Zero Emissions by 2050 Scenario,2023-2030 IEA.CC BY 4.0.Notes:APS=Announced Pled

80、ges Scenario.NZE=Net Zero Emissions by 2050 Scenario.“Conventional crops”refers to corn,sugarcane,soybeans,canola/rapeseed,palm oil and other crops.“Residue oils”refers to used cooking oil,animal fats,palm oil mill effluent and other residue oils.“New technologies and practices”refers to biofuel pro

81、duction from(lignocellulosic)agricultural and forestry residues,municipal solid waste and oil seeds grown on marginal land through intercropping,double-cropping and other approaches that do not otherwise compete with food and feed production.Sources:IEA(2024),Oil 2024:Analysis and Forecast to 2030;I

82、EA(2023),World Energy Outlook 2023.Nevertheless,this amount of growth still falls well short of the more than doubling of 2023-level production needed by 2030 to put the world on the pathway to net zero emissions by 2050.More than doubling global production would require new biofuel policies and mor

83、e ambitious deployment of new technologies.In all cases,internationally established sustainability frameworks would facilitate growth by stimulating trade and reducing investment risks while also encouraging and ensuring GHG emission reductions.024681012142023Main case forecast 2030APS 2030NZE 2030E

84、JNewtechnologiesResidue oilsConventionalcrops2.5X2XCarbon Accounting for Sustainable Biofuels Chapter 1.Introduction PAGE|15 I EA.CC BY 4.0.Increasing emphasis on GHG emission reduction policies Biofuel uptake is strongly driven by supportive policies and regulations,based on key objectives such as

85、ensuring energy security,reducing GHG emissions and diversifying fuel sources to mitigate the impacts of fossil fuel price volatility.Biofuels are recognised for their effectiveness in decarbonising transport and other hard-to-abate sectors.However,large-scale biofuel use can also be associated with

86、 a number of economic,environmental and social risks,potentially leading to negative biodiversity impacts,the depletion of organic carbon in the soil,deforestation,objectionable labour conditions,disputes over land use rights and higher food prices,among other effects.It is therefore essential to ad

87、opt sustainable practices,advance technological innovations and implement supportive policies for biofuel production and use.Policy tools such as performance-based sustainability criteria,land use planning,adaptive blending requirements and other approaches are used to mitigate impacts in biofuel pr

88、oducing countries.GHG accounting and carbon intensity Biofuel sustainability can be quantified with the help of GHG emission accounting tools,used to calculate the lifecycle GHG emissions associated with a biofuels production and use.The result is expressed in grammes of CO2-equivalent per megajoule

89、 of biofuel produced(gCO2-eq/MJ).CO2-equivalent include not only CO2 but also other gases with warming potential,such as methane or N2O.In some policy frameworks,this is also known as carbon intensity or carbon accounting.In all cases,carbon refers to CO2-equivalent,including CO2,methane,N2O and oth

90、er greenhouse gases.Common wordings in selected policy frameworks to address GHG emissions Policy framework Common wording European Union,RED GHG emission reduction/accounting United States,RFS GHG emissions/reduction California,LCFS Carbon intensity Brazil,RenovaBio GHG emissions,carbon intensity C

91、ORSIA Life cycle emissions values,GHG,carbon emissions IMO GHG emissions,GHG intensity Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|16 I EA.CC BY 4.0.Chapter 2.Policy environment Regulatory approaches Biofuel production and use is driven by supportive policies and reg

92、ulations,founded on objectives related to reducing GHG emissions,diversifying fuel sources to mitigate the impacts of fossil fuel price volatility,and improving energy security.Figure 2.1 maps selected global biofuel policy frameworks and their main features in various regions and markets.The Carbon

93、 Offsetting and Reduction Scheme for International Aviation(CORSIA)is an initiative developed by the International Civil Aviation Organization(ICAO)to address the increase in CO2 emissions from international aviation.The International Maritime Organization(IMO)is also developing a similar regulation

94、 for international shipping.Both provide good examples of international biofuel policy frameworks.Figure 2.1 Features of main regional and international biofuel policy frameworks Notes:Regions/jurisdictions featured in the map are Canada,the United States,Brazil,the European Union,India,China,Indone

95、sia and Australia.The IMO regulation is still under development,although important progress is expected before the end of 2024.Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|17 I EA.CC BY 4.0.Volumetric targets or mandates(e.g.blending mandates),the most common form of

96、biofuel regulation today,are used to develop markets and support investments.Globally,biofuel blending stands at nearly 6%on a volumetric basis,with major markets ranging from 4%(India)to 27%(Brazil).Medium-term targets for biofuels vary considerably by country in terms of ambition and type of goal.

97、Across advanced economies,targets are increasingly being presented as regulated GHG intensity reductions,for instance in Californias Low Carbon Fuel Standard(LCFS),Canadas Clean Fuel Regulations(CFR)and the EU Renewable Energy Directive(RED).These targets apply to the transport sector as a whole and

98、 not to biofuels specifically.However,these GHG targets are often implemented in concert with volume or energy targets for biofuels.For instance,EU member states continue to use biofuel blending mandates to meet the EU renewable energy targets.In the United States,the Renewable Fuel Standard sets bi

99、ofuel volume targets,and in Canada most provinces have blending mandates that often also include GHG performance requirements.In emerging economies such as India,Indonesia and Brazil,targets are set as fixed volumes.Brazil also includes GHG emission reduction ambitions in its RenovaBio programme.Suc

100、cessful biofuel programmes also depend on a number of other policy interventions,such as stimulus for flex-fuel vehicles(in the case of Brazil),production and capital incentives,fuel standards and feedstock limits.While these other policy interventions certainly support biofuel investment and use,th

101、ey fall outside the scope of this report.Table 2.1 Current biofuel shares in transport fuels and near-term targets for selected countries,regions and CORSIA Current level*Targets Brazil 27%Existing:Up to 27%ethanol blending;up to 35%under discussion 2025:Up to 15%biodiesel blending 2033:74 million c

102、arbon credit reductions in the transport sector Canada 8%2030:15%reduction in carbon intensity of liquid fuel sold in Canada from 2016 baseline China 1%2025:50 000 t of sustainable aviation fuel to be used between 2022 and 2025 European Union 7%2030:14.5%GHG intensity reduction or 29%renewable conte

103、nt on an energy basis(including double-counting provisions)India 4%2025/26:20%ethanol blending target 2030:5%biodiesel blending target 2028/29:5%compressed biogas blending target Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|18 I EA.CC BY 4.0.Current level*Targets Indo

104、nesia 17%2025:35%biodiesel blending target United States 11%2025:22.3 billion gallons of ethanol equivalent(84.4 billion litres of ethanol equivalent)ICAO 1%2030:Aspirational goal of 5%CO2 emission reduction in aviation from using sustainable aviation fuel,lower-carbon aviation fuel and other cleane

105、r aviation energy sources*Volumetric shares of biofuels in total diesel and gasoline demand as of 2023.In the next five years,nearly 40%of road transport fuel demand will be covered by policies incentivising lifecycle carbon reductions,marking a shift from traditional biofuel blending mandates.The v

106、alue of these credits differs by market,with credits worth up to USD 0.26/litre for renewable diesel in the United States under the planned Clean Fuel Production Credit,and USD 0.03/litre for ethanol in Brazil according to average 2023 credit prices.To reduce emissions from transport,most frameworks

107、 have also established thresholds for minimum GHG performance.Such requirements can be combined with additional sustainability requirements for biofuels to avoid negative impacts in other environmental categories such as biodiversity.A further measure could be to offer additional support for some sp

108、ecified feedstocks(e.g.animal manure for biogas production,or double-counting of feedstocks for advanced biofuels as defined in Annex IX of the EU Renewable Energy Directive).Some biofuel policy frameworks also incorporate mechanisms that reward biofuel producers for improved GHG performance.Such re

109、wards can take various forms:for instance,programmes such as Californias LCFS set a carbon intensity benchmark for fuels,and biofuels with carbon intensity scores below the benchmark generate credits that can be sold to producers of higher-carbon fuels,rewarding biofuel producers for reducing GHG em

110、issions.Under RenovaBio,Brazils national biofuels policy,better GHG performance results in the issuance of more decarbonisation credits(CBIOs)that biofuel producers can sell to fuel distributors that need to meet their decarbonisation targets.Finally,governments also employ various measures to bridg

111、e biofuel cost gaps,stimulate production,expand market access,and protect consumers from price increases.For instance,the United States offers a biodiesel blending tax credit of USD 0.26 per litre and plans to extend this credit through the Inflation Reduction Act(IRA)with additional incentives for

112、lower GHG emissions.India sets ethanol purchase prices at levels that allow producers to cover their costs and has reduced tax rates for ethanol and ethanol-blended fuels.In Brazil,fuel distributors must purchase decarbonisation credits(CBIOs)to meet the emission reduction targets established by the

113、 RenovaBio programme,which operates under a market-based approach.Across Europe,policy approaches vary:some countries such as France Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|19 I EA.CC BY 4.0.offer tax breaks on high-ethanol blends(85%),while others pass the costs

114、 on to consumers.Indonesia uses palm oil export levies to subsidise biodiesel costs.Despite the potential of large-scale biofuel use to reduce demand for fossil fuels,it can also present economic,environmental and social risks.Various publications and wider scientific debates have examined the role

115、and extent of these risks,prompting the adaptation of policy frameworks,the introduction of more diverse sustainability criteria and requirements in some regions and countries,and new approaches for assessing the impacts of bioenergy(e.g.ISO 13065).In any case,demonstrating the net lifecycle GHG emi

116、ssion reductions that can be gained with bioenergy is essential to obtain public acceptance and secure continuous future support through policy instruments.Carbon accounting approaches An important aspect regarding the sustainability of biofuels is GHG emissions associated with its production and us

117、e,as well as the emission savings in comparison to other fuels.These effects can be quantified with the help of carbon accounting,which involves calculating the lifecycle GHG emissions of producing and using of a biofuel.Several policy frameworks provide specific guidance on calculating GHG emission

118、s from biofuels and how compliance with GHG reduction requirements should be verified.These are based on widely recognised lifecycle assessment(LCA)methodology,including the ISOs 14000 series of environmental management standards,particularly ISO 14040 and ISO 14044.The ISO states that LCAs evaluate

119、“environmental aspects and potential impacts throughout a products life cycle(i.e.cradle-to-grave)from raw materials acquisition through production,use and disposal.The general categories of environmental impacts needing consideration include resource use,human health,and ecological consequences.”Bi

120、ofuel carbon accounting generally takes only GHG emissions into consideration.The various accounting approaches reflect regional conditions,the sectors development status and feedstock dependency(Figure 2.2).Emissions associated with producing and using biofuels excluding land use change impacts are

121、 referred to as core LCA values under the CORSIA framework and the California LCFS.Several frameworks,such as those of the United States and Brazil,permit the use of default values for total or partial emissions,or the calculation of individualised pathways with specific standardised calculation too

122、ls(e.g.GREET in the United States,CA-GREET and other GREET-based calculators in California,and RenovaCalc in Brazil).In the European Union,biofuel producers can use default Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|20 I EA.CC BY 4.0.values that correspond to upper-

123、bound(not average)emissions,or can calculate their own actual GHG emission values to demonstrate superior performance,based on a methodology defined in RED III allowing for the use of different calculators.Values are then verified through a certification system involving a third-party audit by an in

124、dependent certification body.Figure 2.2 Carbon accounting approaches in selected policy frameworks IEA.CC BY 4.0.Notes:LCA=lifecycle assessment.dLUC/iLUC=direct/indirect land use change.In core LCA values,Brazils RenovaBio presents default values for the agricultural phase only.The main biofuel poli

125、cy frameworks also differ in how emissions from direct and indirect land use change are considered.Direct land use change(dLUC)refers to the direct conversion of land from one use to another to produce biofuels,while indirect land use change(iLUC)occurs when biofuel production indirectly causes chan

126、ges in land use elsewhere.Due to the indirect nature of iLUC it cannot be measured or verified,only estimated using economic models.Frameworks such as the California LCFS,the US Environmental Protection Agencys(EPA)Renewable Fuel Standard(RFS)and CORSIA use customised models to estimate potential em

127、issions from overall land use change for biofuel pathways and include them in regulations.Meanwhile,biofuel producers selling their products in the European Union under RED III must individually calculate emissions from direct land use change based on a harmonised methodology if a relevant land use

128、change event has been identified in their production processes.Emissions from indirect land use change Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|21 I EA.CC BY 4.0.are not quantified at the biofuel producer level.However,member states report iLUC emissions resulting

129、 from their policies to the European Commission using standardised default values for iLUC emissions across the European Union.Furthermore,the EU RED III includes detailed instruments to make biofuels with low iLUC risk eligible,while biofuels with high iLUC risk are subject to progressive quota lim

130、itations or are completely excluded in some sectors.Other regulations,such as CORSIA,IMO and RenovaBio,also consider low-iLUC-risk feedstock categories.International collaboration In addition to the various national policy frameworks,dedicated incentives and rules to develop global markets for susta

131、inable fuels are required to promote the use of biofuels in international transport sectors such as aviation and shipping.The ICAO and the IMO,which are regulatory bodies under the UN framework,have formulated strategies to reduce GHG emissions in their respective sectors.For instance,the ICAO devel

132、oped the CORSIA scheme to address CO2 emissions from international aviation.ICAO has set 85%of 2019 emissions as CORSIAs baseline from 2024 until the end of the scheme in 2035.The strategy involves phased implementation,with a pilot phase(2021-2023)for voluntary participation by states.The first pha

133、se(2024-2026)is similarly voluntary,but with more states participating.In the second phase(2027-2035),the framework will be mandatory for all states with significant international aviation activities,with certain exemptions.To offset emissions that exceed the base levels,airlines are required to pur

134、chase carbon credits from projects that reduce or remove CO2,such as reforestation or renewable energy initiatives.CORSIA also allows airlines to reduce their offsetting requirements by using CORSIA-eligible fuels,which include sustainable aviation fuels and lower-carbon conventional fuels.The Fuels

135、 Task Group of the ICAO Committee on Aviation Environmental Protection develops the standards and methodologies for designating fuels as CORSIA-eligible.The Fuels Task Group has also established standards and methodologies for determining the sustainability of CORSIA-eligible fuels;requirements for

136、certification schemes and a list of approved ones;default carbon intensity values(core and land use change)for a list of pathways and regions;and a detailed methodology for calculating actual carbon intensity.This methodology also addresses how to evaluate and verify low-LUC-risk practices(based on

137、a yield-increase or an unused-land approach),and how to estimate new default LUC values using a combination of two different models(GTAP-BIO and GLOBIOM)and compare them afterwards.When direct LUC has taken place,the dLUC impact is calculated following a detailed methodology.Values from the dLUC cal

138、culation and the LUC models estimate are compared,and the higher amount is used in reporting.Carbon Accounting for Sustainable Biofuels Chapter 2.Policy environment PAGE|22 I EA.CC BY 4.0.The Fuels Task Group is continuously updating and improving methodologies related to eligible fuels for aviation

139、.This working group and all ICAO committees enable in-depth international collaboration among countries and sector-specific organisations.In fact,CORSIAs work on eligible fuels the first global market-based measure in any sector represents a co-operative approach separate from individual national or

140、 regional regulatory initiatives.Meanwhile,the IMO comprises 176 member states(which undertake to comply with IMO regulations and guidelines),three associate countries and 66 observing international organisations.IMO regulations for biofuels are included within its broader framework for reducing air

141、 pollution and GHG emissions from international shipping through various measures and regulations.Key elements are the Energy Efficiency Design Index(EEDI),which mandates minimum energy efficiency levels for new ships,encouraging the use of energy-efficient technologies and designs;the Energy Effici

142、ency Existing Ship Index(EEXI),which regulates minimum energy efficiency levels in existing ship;and the Ships Energy Efficiency Management Plan(SEEMP),which requires ships to have a management plan outlining how they will improve energy efficiency,including operational measures and best practices.F

143、urthermore,ships with gross tonnage of more than 5 000 must collect and report fuel consumption data to the IMO,which uses it to analyse and improve efficiency across the sector.The Initial IMO Strategy on Reduction of GHG Emissions from Ships(2018)and the revised 2023 strategy set targets to reduce

144、 the average carbon intensity of international shipping by at least 40%from the 2008 level by 2030,and to reduce total annual GHG emissions by at least 50%by 2050.Annual operational carbon intensity reductions are compulsory and will be measured and rated.Poor performers will be required to improve.

145、Additionally,work to develop guidelines on lifecycle GHG intensity of marine fuels started in September 2021,following a Well-to-Wake approach.The last version of the guidelines was adopted in March 2024,although the IMO LCA framework is being further developed,as well as other aspects in IMO reduct

146、ion of GHG strategy such as GHG emission pricing.The two frameworks have some notable differences,however.For example,the ICAO primarily uses market-based mechanisms(carbon offsets)while the IMOs current measures are technical(design standards)and operational(management plans).Although CORSIA has gl

147、obal application,initial participation is phased and voluntary,whereas IMO regulations also apply worldwide but are mandatory once in force.CORSIA includes land use change values,while the IMO proposes a risk-based approach for iLUC.Nonetheless,both frameworks represent significant international eff

148、orts to address GHG emissions in global transport.Carbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|23 I EA.CC BY 4.0.Chapter 3.Carbon intensity calculation Lifecycle carbon intensity of biofuels The GHG emissions performance of biofuels is influenced by various

149、calculation parameters related to technical characteristics and local supply chain conditions,affecting carbon intensity to differing degrees all along the biofuel supply chain(Figure 3.1).A typical biofuel production pathway encompasses feedstock cultivation and/or collection,feedstock upgrading an

150、d the conversion process.These elements are connected by transport primarily truck,rail and ship.Figure 3.1 Main parameters considered in carbon intensity calculation for a typical biofuel supply chain IEA.CC BY 4.0.CO2 emissions from biofuel combustion are considered carbon-neutral,as the carbon in

151、 the biomass is produced through photosynthesis,which fixes CO2 from the atmosphere and transforms it into biomass.However,when biofuels are produced from agricultural feedstocks,important parameters to consider are the emissions associated with producing and applying synthetic nitrogen fertilisers,

152、as well as emissions resulting from changes in soil carbon stocks due to either land use changes(LUCs)or specific agricultural practices.For instance,traditional nitrogen fertilisers,for which the fossil fuels used in their production must be recognised,can emit N2O a powerful GHG Carbon Accounting

153、for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|24 I EA.CC BY 4.0.when applied to a field.Concerning soil carbon stocks,some agricultural practices such as applying biochar can increase the amount of organic carbon in soil,reducing overall supply chain GHG emissions.While some c

154、hanges in land use can raise GHG emissions(e.g.transformation from grassland to agricultural land),others can reduce emissions(e.g.reconversion of marginal or degraded land into agricultural land).LUC emissions are either direct or indirect.Direct land use changes(when bioenergy cropping replaces a

155、different land use)is relatively well understood and can be measured and monitored over time.However,indirect land use change occurs when a bioenergy crop replaces a food or feed crop and,as a result,food or feed production is displaced elsewhere to compensate for the gap.Only complex models that en

156、compass energy and agricultural markets can estimate iLUC emissions.Using biogenic wastes and residues as biofuel feedstock,which is obviously independent from land use change,can further mitigate emissions from these materials,as conventional waste treatment practices may produce significant GHGs.T

157、he RED III framework includes these avoided emissions(e.g.from animal manure)in its carbon intensity calculations.As emissions from transport and conversion processes typically originate from the supply and use of energy carriers and process chemicals,using renewable fuels or renewable electricity c

158、an significantly reduce the impacts of the processing and transport stages.Furthermore,especially for fermentation and anaerobic digestion processes,capturing and subsequently using or sequestering the produced CO2 can significantly reduce biofuel supply chain GHG emissions.In some biofuel productio

159、n processes,other coproducts are generated along with the biofuel,for instance corn oil or distillers dried grains with solubles(DDGS)for animal feed in the production of ethanol from corn,and steam and electricity produced from bagasse in sugarcane mills.Feedstock and process emissions are allocate

160、d to the different end products based on mass,energy or revenue,depending on the regulatory framework.Methodological decisions Both default and individual values for biofuel carbon intensity are typically calculated based on principles set out in a lifecycle assessment(LCA)methodology(as defined in

161、ISO standards 14040 through 14044).LCA is a commonly recognised methodology for assessing environmental impacts of products and services,and it is applied widely in both science and industry.However,while LCA provides a solid framework,the ISO standards have a certain amount of flexibility in defini

162、ng key methodological aspects.Consequently,factors Carbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|25 I EA.CC BY 4.0.such as system boundaries,coproduct handling principles and impact assessment methodologies are often specified in the rules governing the calcu

163、lation of biofuel carbon intensities.Table 3.1 enumerates how some methodological aspects are defined under selected frameworks.Table 3.1 Key methodological features under selected frameworks California LCFS EU RED II/III Brazil RenovaBio ICAO CORSIA Model for calculating default and individual core

164、 values CA-GREET model Default values for multiple pathways and methodology for individual calculations in RED II,Annex V RenovaCalc tool ICAO-GREET model and other tools Model for calculating iLUC GTAP-BIO and AEZ-EF MIRAGE-BioF,GLOBIOM-Combination of GTAP-BIO and GLOBIOM Coproduct allocation or di

165、splacement method Energy allocation for fuel products;displacement method for DDGS and electricity surplus Energy-based in general;exergy allocation for combined heat and power Energy-based Energy-based LCA approach Attributional and consequential(LUC)Attributional Attributional Attributional and co

166、nsequential(LUC)Main emission factors database CA-GREET Biograce and JRC database Ecoinvent GREET and JRC,among others Global warming potential(GWP)in use IPCC protocol 100-year GWP AR4 100-year GWP AR5 100-year GWP AR5 100-year GWP AR5 Notes:GREET=Greenhouse gases,Regulated Emissions and Energy use

167、 in Technologies model.CA-GREET=California GREET.IPCC=Intergovernmental Panel on Climate Change.JRC=EC Joint Research Centre.DDGS=distillers dry grains with solubles.Sources:Californias LCFS 2020;RED III 2023.Calculation models and tools In addition to methodological principles,GHG calculation model

168、s and tools are another key element for implementing GHG-related biofuel policy requirements.However,the various GHG emission calculation processes and verification methods differ considerably.Numerous countries have implemented procedures to calculate either default and/or individualised values for

169、 biofuel pathways in a consistent manner,enabled Carbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|26 I EA.CC BY 4.0.by a harmonised methodology and centralised calculation tools.Frameworks in the United States,Canada and Brazil utilise more centralised approache

170、s,while under the EU RED and CORSIA frameworks,biofuel producers usually conduct GHG calculations themselves,followed by external verification(Table 3.2).Table 3.2 Overview of selected GHG calculation models used by the main biofuel policy frameworks GREET RenovaCalc EU RED methodology*Fuel Life Cyc

171、le Assessment Model Jurisdiction US RFS,CA LCFS,CORSIA and others,using different specific versions of the model Brazil European Union Canada Developer Argonne National Laboratory,funded by the US Department of Energy Brazilian research institutions(Embrapa,LNBR,Agroicone and Unicamp)European Commis

172、sion Joint Research Centre(JRC)Environment and Climate Change Canada Scope Transport fuels and fuel and vehicle combinations Different biofuels,transport fuels Biofuels for transport,heat and electricity Transport fuels Main purpose Comparison of energy use,vehicle emissions,fuel combinations Assess

173、ing the GHG emissions performance of biofuels Comprehensive GHG calculator for biofuel process chain elements LCA of current and future fuels for transport applications Featured feedstocks and technologies More than 100 fuel pathways including petroleum fuels,natural gas fuels,biofuels,synthetic fue

174、ls,and hydrogen and electricity produced from various energy feedstock sources First-and second-generation sugarcane ethanol,corn ethanol,biodiesel,biomethane and biokerosene First-and second-generation biofuels from rapeseed,sugar beet,sugarcane,wheat,corn,barley,rye,triticale,palm oil,wood,used co

175、oking oil,soybeans,etc.Covers fuel and feedstock combinations under the Clean Fuel Regulations Geographic input data availability United States with some pathways from other regions Brazil Global supply chains with a focus on EU application Mainly Canada,United States Mexico,India*Available in RED A

176、nnexes V and VI.Notes:Embrapa is the Brazilian Agriculture Research Institute.LNBR is Brazils National Biorenewable Laboratory.Table 3.2 calculation models focus on emissions stemming from biomass cultivation and its transformation into biofuels,and from transport.However,various other models have b

177、een developed to assess emissions linked to potential LUCs resulting from biofuel production.Some of the most relevant ones are the GLOBIOM and GTAP-BIO used in CORSIA for iLUC modelling,and the GREET CCLUB and the Blonk LUC impact model for dLUC.Carbon Accounting for Sustainable Biofuels Chapter 3.

178、Carbon intensity calculation PAGE|27 I EA.CC BY 4.0.Land use change evaluation Emissions from direct and indirect land use change can contribute significantly to the carbon intensity of biofuels.Thus,policy frameworks have recognised their importance and integrated different approaches for taking th

179、em into account.In the context of biofuel sustainability,the IPCC defines land use changes as modifications pertaining to six land categories:forest,grassland,cropland,wetland,settlements,and other land.This means,for example,that a transition from forestland or grassland to cropland is considered a

180、 land use change,while shifting from one crop to another is not.Cropland includes fallow land.Equally,changes in management activities,tillage practices or manure input are not considered land use changes under the IPCC definition.Emissions from direct land use changes can be observed and quantified

181、.Analysing alterations in carbon stocks over time before and after use changes can be a verifiable way to calculate important direct land use emission changes associated with feedstock production.Instructions on how to calculate emissions associated with direct LUC are included in the CORSIA methodo

182、logy and in RED II,Annex VI B7.In contrast,emissions from indirect land use change cannot be observed directly.Under policies such as CORSIA and the California LCFS,indirect land use change emissions are estimated by using global economic equilibrium models designed to evaluate market responses to f

183、eedstock or biofuel demand changes.Other policies such as the EU RED use a risk-based approach to promote feedstocks with low indirect land use change risks,avoiding the quantification of indirect land use change emissions.Table 3.3 Overview of land use change evaluation in selected biofuel policy f

184、rameworks Consideration of dLUC and iLUC California LCFS Includes emissions from induced land use change(direct+indirect)using a single general equilibrium model covering both domestic and international LUC.Brazil Addresses direct LUC through eligibility criteria that include complying with Brazilia

185、n environmental legislation.Biomass from areas where native vegetation has been suppressed is banned.European Union dLUC values must be calculated when there has been direct land use change.dLUC on land with high carbon stocks is prohibited.Contribution from high-iLUC-risk feedstocks is progressivel

186、y being banned.Low-iLUC-risk feedstocks can be certified.Carbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|28 I EA.CC BY 4.0.Consideration of dLUC and iLUC India Not included.Canada CFR Prohibition on high-iLUC-risk feedstocks.CORSIA Requirement to calculate and

187、report individualised dLUC when there has been land conversion.Default LUC values are calculated by combining the results of two different models.When the dLUC value is calculated,the higher value between dLUC and iLUC is chosen.Biofuels obtained from land with high carbon stocks are prohibited.Note

188、s:dLUC/iLUC=direct/indirect land use change.CFR=Clean Fuel Regulations.The need to use models to estimate iLUC arises from the complexity and interconnectedness of global agricultural markets and land use dynamics.However,the use of models is controversial,with critics highlighting several key issue

189、s.First,models often rely on numerous intricate assumptions and variables,leading to significant uncertainties and potential inaccuracies in their predictions.Second,iLUC models may overgeneralise,failing to consider regional differences in agricultural practices,land availability and economic condi

190、tions,and in general tend to inadequately account for technological advancements and improvements in agricultural efficiency that could mitigate negative impacts.Additionally,models can be sensitive to input data,meaning that small changes in assumptions or among data sources can lead to vastly diff

191、erent outcomes.Furthermore,as models used to assess the economic response do not take illegal or informal activities that also contribute to land use change into account,they may be attributing their effects to the formal economy.Hence,critics generally advocate for more transparent,robust and empir

192、ically grounded approaches to evaluate iLUC impacts.Variability in calculation results Although core lifecycle assessment of biofuels is well understood,the available literature shows a wide range of GHG emission results across different biofuel value chains.Figure 3.2 presents the carbon intensitie

193、s of several biofuels cited by various sources,compared with RED default values.The wide range of results makes generalisation difficult and,above all,emphasises the importance of recognising the diverse factors that lead to calculation variabilities.Carbon Accounting for Sustainable Biofuels Chapte

194、r 3.Carbon intensity calculation PAGE|29 I EA.CC BY 4.0.Figure 3.2 Core lifecycle GHG emission ranges in the literature for selected biofuels IEA.CC BY 4.0.Notes:HVO/HEFA=hydrotreated vegetable oil/hydroprocessed esters and fatty acids.BTL/FT=biomass-to-liquid via Fisher-Tropsch.Values represent cor

195、e LCA emissions,not including land use change emissions.For some biofuel pathways that involve the release of byproduct biogenic CO2,capturing and permanently storing this CO2 can significantly reduce the biofuels carbon intensity,even to the extent that it becomes strongly negative.Default values a

196、re from Annex V of the EU RED II.The BTL/FT default value is based on gasification of farmed wood followed by Fischer-Tropsch synthesis,HVO/HEFA on rapeseed,biodiesel on soybeans,and lignocellulosic ethanol on wheat straw.Fossil fuel range represents gasoline values.Sources:IEA internal data,and IEA

197、 analysis based on European Commission,Joint Research Centre,Padella,M.et al.(2019),Definition of input data to assess GHG default emissions from biofuels in EU legislation;Hennig,C.,et al.(2012),Bioenergy production and use:Comparative analysis of the economic and environmental effects;Mller-Langer

198、,F.,et al.(2014),Benchmarking biofuels a comparison of technical,economic and environmental indicators;Bacovsky,D.,et al.(2010),Status of 2nd Generation Biofuels Demonstration Facilities in June 2010,Majer,S.,et al.(2009);Implications of biodiesel production and utilisation on global climate A liter

199、ature review All biofuel pathways encompass specific combinations of feedstock,regional origins,production processes and final products.In each pathway,there are three primary reasons for core LCA carbon intensity variability:Regional differences geographical variations in value chains,which affect

200、factors such as biomass yield and transport distance,and data such as the emission intensity of the background energy system.Methodological differences variations in key methodological elements of GHG calculations,such as system boundaries,coproduct allocation and displacement principles.02040608010

201、0120BTL/FT(lignocellulosic)HVO/HEFA(oil crops)Biodiesel(oil crops)SilageWaste and residuesSugarcaneLignocellulosicSugar beetCornWheat,ryeFossil fuel comparatorBio-methaneEthanolgCO-eq/MJ(LHV)Fossil fuel rangeBiofuel rangeDefault valueCarbon Accounting for Sustainable Biofuels Chapter 3.Carbon intens

202、ity calculation PAGE|30 I EA.CC BY 4.0.Data source differences discrepancies in data for biofuel production,as well as for the upstream emission factors of process inputs and auxiliary materials,such as process chemicals and fertilisers.These factors can significantly influence overall GHG calculati

203、on results,potentially leading to different outcomes for the same biofuel pathway when feedstock cultivation and biofuel production are conducted by different entities in disparate locations.To better illustrate the nature and potential significance of these elements,the following section examines e

204、xamples of specific biofuel value chains and how their carbon intensity calculations are affected by variability.Regional variations Regional value chain variations involving factors such as biomass yields,transport distances and the emission intensity of the overall energy system can lead to signif

205、icant carbon intensity calculation differences.For instance,GHG emission values are not the same for ethanol made from corn in the United States and in the European Union(Figure 3.3).Figure 3.3 GHG emissions for corn-to-ethanol pathway,cultivated in United States vs European Union IEA.CC BY 4.0.Note

206、s:“United States”calculations are based on US corn cultivation values from ecoinvent 3.10 database.“European Union”calculations are based on values for corn cultivation in Switzerland and the EU electricity production mix,both from ecoinvent 3.10.Overall GHG emissions are 34 gCO2-eq/MJ for ethanol m

207、ade from corn in the United States,versus 37 gCO2-eq/MJ in the European Union.The differences stem from emissions associated with corn production(higher in the European Union)and process electricity use(lower in the European Union),leading to lower overall emissions for the US pathway.0 10 20 30 40U

208、nited StatesEuropean UniongCO-eq/MJ(LHV)Transport/distributionProcessing(other)Processing(electricity)Corn productionCarbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|31 I EA.CC BY 4.0.It is important to note that regional differences are real,and it is important

209、 to account for them correctly.Methodologies should allow to use data and pathways that are representative of each country or region characteristics.Methodological variations Variations in key methodological aspects of GHG calculations,such as system boundaries and coproduct handling(allocation or d

210、isplacement principles)can lead to significant carbon intensity calculation differences.Many biofuel pathways produce coproducts such as fodder,fertiliser and energy in addition to liquid or gaseous transport biofuels;these coproducts should be factored into the biofuels carbon intensity calculation

211、s.International standards for lifecycle assessment,such as ISO 14040,provide guidance on the allocation of coproducts but often leave room for interpretation.There are several common coproduct handling methods:using an allocation ratio based on a products properties(e.g.mass,energy or market value)o

212、r using a displacement GHG credit,assuming the coproduct is going to displace a similar product in the market.Carbon intensity calculations under policy frameworks such as the EU Renewable Energy Directive,RenovaBio and CORSIA are standardised,requiring a single defined allocation method for all cop

213、roducts within a value chain(i.e.energy-based allocation,which generally reflects a higher energy-to-mass ratio for the biofuel).This approach ensures greater comparability among different biofuel pathways and allows for easier third-party verification,as it limits subjective choices,for example in

214、displacement methods.Depending on the biofuel pathway and the number/amount of coproducts,the allocation approach can affect carbon intensity calculations for the biofuel product.Figure 3.4 illustrates this effect for a starch crop-based bioethanol pathway,with ethanol and coproduct(DDGS)emissions a

215、llocated based on mass flow(31 gCO2-eq/MJ),energy content(44 gCO2-eq/MJ)and economic value(40 gCO2-eq).Carbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|32 I EA.CC BY 4.0.Figure 3.4 Impact of DDGS coproduct allocation on the GHG emissions of starch crop-based bio

216、ethanol IEA.CC BY 4.0.Notes:LHV=lower heating value.DDGS(distillers dried grains with solubles)is a cereal byproduct of the distillation process that is commonly sold as a livestock feed.Data corresponds to EU average values.A special case is the consideration of byproducts,residues and waste stream

217、s,which,contrary to coproducts,do not share upstream emission burdens with the main products.Another potential methodological difference arises from the setting of system boundaries.While most regulatory frameworks for biofuels rely on attributional approaches for their core GHG values,estimating la

218、nd use change requires a consequential approach.Additionally,not all methodologies take account of avoided emissions throughout the process chain,which can potentially come from avoided cultivation emissions(owing to improved agricultural management,cover crops,etc.),waste treatment(animal manure an

219、d avoided methane emissions)and carbon capture.Data source variations As LCA practitioners often rely on databases for information on upstream emissions of process inputs and auxiliary materials such as process chemicals and fertilisers,data source variability can also lead to differences in carbon

220、intensity calculations for the same biofuel pathway.0 10 20 30 40 50Mass allocationEnergy allocationEconomic allocationgCO-eq/MJ(LHV)DistributionEthanolproductionTransportFeedstockcultivationCarbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|33 I EA.CC BY 4.0.Figu

221、re 3.5 Influence of different data sources on the carbon intensity of biofuel feedstock IEA.CC BY 4.0.The study Greenhouse Gas Emissions from Inorganic and Organic Fertilizer reviews available emission factors for different fertilisers,which are an important input in agricultural production and a re

222、levant parameter for calculating the carbon intensity of biofuels.For example,Figure 3.5 illustrates calculations of GHG emissions from sugar beets produced as feedstock for biofuel,using two different emission factors for the nitrogen fertiliser leading to either 28 gCO2-eq/MJ or 36 gCO2-eq/MJ.Rele

223、vance of different parameters on overall carbon intensity While all supply chain steps influence a biofuels overall lifecycle carbon intensity,some factors are more relevant than others.For instance,parameters involving biomass cultivation generally have a particularly high relative impact on overal

224、l GHG emissions.Table 3.4 summarises the main parameters influencing the carbon intensity of biofuels.A more detailed table providing additional information,including on accounting complexity and quantification uncertainty,is included in the Annex.0 5 10 15 20 25 30 35 40Emission factorEmission fact

225、orsource 1source 2kgCO-eq/kg sugarbeetNO emissionsSeedsOther agrochemicalsN-fertiliserDieselCarbon Accounting for Sustainable Biofuels Chapter 3.Carbon intensity calculation PAGE|34 I EA.CC BY 4.0.Table 3.4 Relative relevance of different of supply chain parameters for overall biofuel carbon intensi

226、ty Value chain element Relevant parameters for GHG accounting Relative relevance Biomass cultivation dLUC High iLUC High Fertilisation production of fertilisers High Fertilisation application and losses High Use of agricultural machinery for cultivation and harvesting Low Soil carbon accumulation ow

227、ing to improved agricultural practices Medium to high Use of residues for biofuel production Loss of soil organic carbon due to the use of agricultural residues Medium to high Avoided emissions in other product systems Medium Transport Transport distance and type of energy carrier Low to medium Biom

228、ass conversion to biofuel Emissions from energy consumption Medium Emissions from the production of chemicals Low Direct process emissions Low to medium BECCUS*process energy consumption Low BECCUS substitution effects Medium to high*Bioenergy with carbon capture and storage.Carbon Accounting for Su

229、stainable Biofuels Chapter 4.From lifecycle assessments to policy making PAGE|35 I EA.CC BY 4.0.Chapter 4.From lifecycle assessments to policy making While lifecycle assessment(LCA)models are already used in many countries to support policies and regulatory frameworks for biofuel sustainability,the

230、plethora of methodologies and tools available and the wide range of calculation results signals the intricacy of using carbon accounting for policy making purposes.Achieving consensus on methodologies and a better understanding of the parameters influencing the overall carbon intensity of biofuels(a

231、s described in the previous chapter)could at least partially reduce the complexity and variability of results.Nevertheless,some complexity and uncertainty will persist because it cannot be resolved at the methodological or technical expert level.Policymakers will therefore need to make decisions to

232、account for this ambiguity in the most pragmatic and effective ways.It will also be important that policies foster continuous biofuel sustainability improvements,and that methodologies for analysis and verification are designed and implemented accordingly.GHG emission thresholds Many biofuel policie

233、s establish minimum GHG emission reduction requirements for production pathways to ensure that biofuels contribute effectively to national GHG reduction targets(Table 4.1).Compliance is typically demonstrated by comparing a biofuels carbon intensity with a reference value,usually based on a mixture

234、of petroleum-derived transport fuels.To streamline the process,default or standard values are often used.These values may be included directly in policy instruments,such as the RED III Annex,or provided by authorised entities such as the US Environmental Protection Agency(EPA)for the Renewable Fuel

235、Standard.Table 4.1 Biofuel GHG reduction requirements in selected policy frameworks GHG reduction thresholds United States(RFS*)20%reduction in conventional biofuels compared with fossil fuels,50%for advanced fuels and 60%for cellulosic biofuels Brazil Specific annual GHG reduction 2024 target:16-17

236、%reduction;2033 target:25%reduction European Union(RED III)50%reduction compared with fossil fuels when operational before 2015,60%when start of operations is 2015-2020,65%in or after 2021 India No specific GHG requirements CORSIA 10%reduction compared with fossil fuels*The Renewable Fuel Standard p

237、rogramme.Carbon Accounting for Sustainable Biofuels Chapter 4.From lifecycle assessments to policy making PAGE|36 I EA.CC BY 4.0.A biofuels carbon intensity must fall below the target or threshold value to be in compliance with(and benefit from)these programmes.The required GHG reduction is usually

238、defined as a percentage decrease from the fossil fuel reference value.Furthermore,the minimum threshold can become stricter over time.For instance,the EU RED III mandated a 50%reduction before October 2015;60%between November 2015 and December 2020;and 65%for plants commissioned from 2021 onwards.Im

239、proving GHG performance The main sources of biofuel carbon intensity in core LCA are well known and can be tackled by the various parties involved in biofuel supply chains if policies are put in place to incentivise them.For example,interventions in the following three areas can improve biofuels GHG

240、 performance.Cultivation and farming Optimising the cultivation process by adopting more sustainable farming practices can reduce emissions significantly.Sustainable agriculture can be achieved through practices such as tailored fertilisation,minimising pesticide use,secondary crops,cover crops,usin

241、g a nutrient management plan,applying compost and biochar,and adopting reduced tillage to increase soil carbon stocks,decrease reliance on agricultural diesel and reduce potential nutrient volatilisation.Figure 4.1 Biofuel GHG emission reduction potential using low-emission fertilisers and fuels in

242、cultivation and farming,for sugar beet-to-ethanol pathway IEA.CC BY 4.0.Source:IEA analysis based on RED II;Vaneeckhaute,C.and E.Walling,(2020),Greenhouse Gas Emissions from Inorganic and Organic Fertilizer.0 10 20 30 40 50Reference caseReduced-emissions casegCO-eq/MJ(LHV)TransportProcessingCultivat

243、ion:Other(cultivation)NO emissionsAgrochemicalsDieselCarbon Accounting for Sustainable Biofuels Chapter 4.From lifecycle assessments to policy making PAGE|37 I EA.CC BY 4.0.Figure 4.1 illustrates GHG emissions from the cultivation and farming of sugar beet-based ethanol in two different cases.While

244、the reference case assumes the use of conventional fertilisers in cultivation and fossil fuels to run the agricultural machinery,low-emission organic fertilisers and biofuels are employed in the improved case,resulting in a 48%drop in cultivation-related GHG emissions.Policy programmes should theref

245、ore recognise and incentivise emission reductions at the farming stage to promote GHG performance improvements.Processing of biofuels In palm oil-based biofuel pathways,the treatment of palm oil mill effluent(POME)is a significant source of emissions,mainly because of the substantial CH(methane)emis

246、sions released during the anaerobic digestion of organic material in the wastewater.However,these emissions can be addressed by enclosing POME treatment systems and flaring the methane emissions or using them for electricity,heat or biogas production.Figure 4.3(left panel)shows a reference-case open

247、 palm oil mill effluent treatment system and an improved case in which POME is treated in a closed system that captures CH emissions,leading to an overall 44%reduction in GHG emissions.Figure 4.2 Biofuel GHG emission reduction potential using palm oil mill methane capture(left)and renewable energy t

248、o process sunflower seeds into biodiesel(right)IEA.CC BY 4.0.Notes:Calculations are based on the Biograce I model.Right graph:electricity grid carbon intensity is the average for the EU grid mix.0 25 50 75ReferenceMethanecasecapturegCO-eq/MJ(LHV)CultivationOil extractionRefiningEsterification0 25 50

249、ReferenceLow-emissioncaseenergygCO-eq/MJ(LHV)CultivationProcessingTransportCarbon Accounting for Sustainable Biofuels Chapter 4.From lifecycle assessments to policy making PAGE|38 I EA.CC BY 4.0.The right-hand panel of Figure 4.3 illustrates a sunflower-to-biodiesel pathway.In a typical biodiesel pr

250、oduction process,the largest contributor to GHG emissions is the transesterification step,primarily due to steam generation,electricity consumption and the production and transport of chemicals consumed in the reaction.As the electricity used in the production processes of several biofuel pathways i

251、s typically sourced from the local electricity grid,the grids carbon intensity can significantly influence the carbon intensity of biofuel production.However,these emissions can be addressed by,for example,switching to low-emission electricity sources.In Figure 4.3(right),the reference case uses fos

252、sil-based energy inputs and electricity from a local grid,while the improved case demonstrates low-emission energy inputs,leading to a 43%reduction in GHG emissions.Capture and storage of biogenic CO2 Some biofuel production processes are associated with the release of considerable biogenic CO2 as a

253、 byproduct,including pathways that use fermentation or gasification,or the upgrading of biogas to biomethane.In these examples,CO2 is released in a highly concentrated form,making its capture relatively affordable(less than USD 30/tCO2).Storing the captured CO2 permanently underground would remove C

254、O2 from the atmosphere and result in negative carbon intensity for biofuels produced in this manner.Other ways to achieve negative carbon intensities for biofuels include producing a solid,high-permanence biochar coproduct(a mixture of carbon and ash)that can be applied to soil.Figure 4.3 GHG emissi

255、on reduction potential using carbon capture and storage for forest residue-based Fischer-Tropsch production using gasification IEA.CC BY 4.0.Note:CCS=carbon capture and storage.Source:IEA analysis based on IEAGHG(2021),Biorefineries with CCS.-125-100-75-50-250 25Reference caseWith CCSgCO-eq/MJ(LHV)C

256、arbon Accounting for Sustainable Biofuels Chapter 4.From lifecycle assessments to policy making PAGE|39 I EA.CC BY 4.0.Figure 4.3 shows how the capture and underground storage of biogenic byproduct CO2 from a biomass gasification plant producing synthetic(Fischer-Tropsch)hydrocarbon fuels can genera

257、te a significantly negative carbon intensity.In the example case,based on forest residues,emissions fall from 5 gCO2-eq/MJ to a deeply negative-117 gCO2-eq/MJ.Direct land use change Direct land use changes(dLUCs)are yet another key source of biofuel emissions.dLUC refers to the conversion of land to

258、 biofuel feedstock production,which can lead to either losses or increases in biomass,dead organic matter and soil organic carbon stocks.Other emissions,such as from biomass burning,are also often accounted for in dLUC.Emissions from land use change are not inherent to any specific biofuel pathway a

259、nd are highly context dependent.In fact,they can result from any production activity in general if appropriate safeguards are not in place.Figure 4.4 illustrates a wheat-to-ethanol pathway based on two different changes in direct land use:the conversion of grassland into agricultural land(for biofue

260、l feedstock production),and the conversion of marginal land into agricultural land.In the grassland case,carbon stocks drop significantly and overall emissions for the biofuel pathway are higher.In contrast,for the marginal land,feedstock cultivation leads to an increase in carbon stocks and decreas

261、ed emissions.Figure 4.4 How direct land use change can affect net wheat-to-ethanol GHG emissions IEA.CC BY 4.0.Direct LUC impacts vary significantly depending on the type of land converted and the resultant changes in biomass,dead organic matter and soil organic carbon-60-40-200 20 40 60 80 100Biofu

262、els fromprevious grasslandBiofuels from previousmarginal landgCO-eq/MJ(LHV)Direct land use changeTransport and distributionProcessingCultivationTotal emissionsIncrease ofcarbon stockDecrease ofcarbon stockCarbon Accounting for Sustainable Biofuels Chapter 4.From lifecycle assessments to policy makin

263、g PAGE|40 I EA.CC BY 4.0.stock.For instance,converting grassland or forest into agricultural land can result in substantial emissions,whereas converting degraded or marginal land can lead to emission savings,reducing total GHG emissions from 92 gCO2-eq/MJ to 12 gCO2-eq/MJ(Figure 4.4).It is important

264、 to note that dLUC effects must be calculated based on actual data whenever possible,as it is difficult to make generalisations regarding the magnitude of these emissions.In contrast with dLUC effects,which can generally be observed explicitly,measured and attributed to a specific activity,the impac

265、ts of indirect land use change have to be modelled because they cannot be generally observed directly.Frameworks such as CORSIA and the LCFS use economic equilibrium or partial equilibrium models to assess market responses to additional demand for biofuel feedstocks.iLUC emissions of the produced fu

266、el can be estimated based on this information.Uncertainty and impact The foregoing examples illustrate the complex and diverse array of factors affecting the carbon intensity of biofuels.As a result,biofuel pathways based on identical feedstocks and employing the same conversion technologies can yie

267、ld significantly divergent GHG emission reductions.However,understanding the significance of the various factors is crucial to develop effective incentives to further reduce GHG emissions.Figure 4.5 groups the main determinants of GHG emissions in biofuel pathways by their relative impact on emissio

268、n reductions(vertical axis)and by the uncertainty associated with quantifying their emission reductions(horizontal axis).For factors that have higher uncertainty,final GHG reductions after their implementation can be very different from initial theoretical calculations,so final achievements must be

269、verified.The visual representation of these two axes can help policymakers identify how policy interventions could most effectively improve GHG performance.The green circle highlights parameters that have a potentially high impact on the carbon intensity of biofuel pathways.Additionally,the quantifi

270、cation of these effects is associated with relatively lower uncertainty.These interventions which include advanced wastewater treatment to reduce emissions from oil mills;CO2 capture and storage from conversion processes;and the use of renewable energy throughout the biofuel value chain are accessib

271、le strategies for biofuel producers to improve their GHG performance.Leveraging the GHG reduction potential associated with these parameters may,however,require additional technical installations,leading to increased production Carbon Accounting for Sustainable Biofuels Chapter 4.From lifecycle asse

272、ssments to policy making PAGE|41 I EA.CC BY 4.0.costs.Nevertheless,they can be addressed relatively quickly and easily if the right incentives are in place,such as price premiums for biofuels that achieve additional GHG2 reductions.Figure 4.5 Impacts and uncertainties of the main biofuel carbon inte

273、nsity determinants IEA.CC BY 4.0.Notes:BECCS=bioenergy with carbon capture and storage.BECCU=bioenergy with carbon capture and utilisation.POME=palm oil mill effluent.dLUC=direct land use change.iLUC=indirect and use change.Parameters in the yellow circle,such as direct land use change emissions,emi

274、ssions associated with nitrogen fertiliser application and the capture and utilisation of biogenic CO2,have a relatively strong impact but are more complex to quantify for various reasons and present greater uncertainty.Policy or market incentives that economically reward biofuels with high GHG redu

275、ction potential could help mitigate emissions associated with these parameters.However,it is important that policy measures include additional effort and attention to verify GHG reduction effects in practice,as emission reduction calculations can be unreliable.Using certification as a verification i

276、nstrument could be a viable option for policymakers to ensure that expected GHG reductions are in fact achieved.Finally,emissions from indirect land use change(iLUC,in the red circle)have potentially high impact,influenced by factors such as overall biofuel targets and the market shares of different

277、 biofuel feedstocks.Quantifying iLUC emissions within policy frameworks that promote biofuels typically relies on models that assess how markets respond economically to increasing biofuel demand and the resulting land use changes.Therefore,this quantification cannot be performed by Carbon Accounting

278、 for Sustainable Biofuels Chapter 4.From lifecycle assessments to policy making PAGE|42 I EA.CC BY 4.0.individual market actors or biofuel producers.Given that the impacts of iLUCs are beyond the direct control of biofuel producers or verification instruments such as certification schemes,additional

279、 policy measures are essential.Effective land use policies,including the protection of food security,natural forests and areas with high biodiversity or carbon stock,are necessary to address these challenges.Some regulations,such as those in the European Union and Canada,include an iLUC risk approac

280、h,wherein feedstocks that have a high potential iLUC risk are banned or limited.To recognise improved agricultural practices that do not involve iLUCs,several frameworks have a category for low-iLUC-risk feedstocks(the European Union,Canada and CORSIA).These practices,contrary to general iLUC estima

281、tes,can be verified at the project level and are therefore recommended as a way to minimise iLUC effects.Carbon Accounting for Sustainable Biofuels Chapter 5.Conclusions and policy considerations PAGE|43 I EA.CC BY 4.0.Chapter 5.Conclusions and policy considerations To significantly accelerate the d

282、eployment of sustainable biofuels,policies should stimulate their continuous improvement based on up-to-date GHG performance metrics and compliance with other sustainability criteria,as well as upscaling of the best technologies.Countries should also demonstrate strong leadership by promoting consis

283、tent political guidance for GHG accounting,adhering to transparent methods and developing international standards.Governments should employ pragmatic,impact-oriented approaches to account for the varying levels of complexity and uncertainty inherent in lifecycle assessments of various biofuel pathwa

284、ys.While detailed policy descriptions and roadmaps for their implementation are beyond the scope of this study,a list of key policy priorities is given below,underpinned by methodological and data best practices and international and stakeholder involvement.Methodology and data best practices Suppor

285、t the use of transparent and consistent methodologies,and the best available measurable and verifiable data for GHG accounting.GHG accounting relies on lifecycle assessments(LCAs)that are highly data-intensive and entail consistency-and representativity-related challenges.Data should come from credi

286、ble,publicly accessible sources that can be cited and used for replicable analyses that strive to represent relevant geographical contexts and situations.Foster consistent application of system boundaries across different biofuel pathways and the fossil fuels they replace.Sustainable biofuels can be

287、 produced using a wide range of pathways based on various feedstocks(including wastes and residues),manufacturing processes and coproducts.GHG assessments need to be transparent and comparable across different pathways to enable incentives for continual improvement and promote innovation.Performance

288、 evaluations should use actual supply chain data and reflect any improvements that could produce the best-performing biofuels,regardless of technological features or feedstock.Comparisons should be based on equivalent system boundaries.Encourage the collection and use of data that correctly reflect

289、actual practices and regional conditions.As information related to agricultural Carbon Accounting for Sustainable Biofuels Chapter 5.Conclusions and policy considerations PAGE|44 I EA.CC BY 4.0.practices,processing and other biofuel production steps can vary significantly across countries and over t

290、ime,policymakers need to ensure that models use up-to-date data that cover all current practices and uncertainties.Additionally,as regional circumstances(e.g.climate,type of land use and soil quality)can differ significantly from one area to another,data should represent real conditions,avoiding gen

291、eralisations and extrapolations from one region to another.Most frameworks make this possible by allowing the use of actual rather than default values,making it possible to producers to demonstrate better performance by certifying their value chains.However,new and streamlined approaches must be dev

292、eloped and put in place to allow small producers in all jurisdictions to participate using actual values.Provide guidance on monitoring and measuring the verifiable effects of land use changes.Emissions from direct land use changes are relatively well understood and can be observed and quantified ac

293、cording to the IPCCs six land use categories.Analysing alterations in carbon stocks over time before and after use changes is a measurable and verifiable way to assess important direct land use emission changes associated with feedstock production.Direct land use changes should be systematically inc

294、luded in carbon accounting methods and relevant policies.In contrast,quantitative impacts of indirect land use changes allocated to a specific biofuel pathway cannot be measured or verified,only modelled.This makes it extremely difficult to objectively compare the GHG intensities of different biofue

295、ls or with other sustainable fuels(e.g.hydrogen and derived fuels).Policy priorities Establish policies that reward better GHG performance and drive continuous improvement.The carbon intensity of a biofuel pathway,expressed in gCO2-eq/MJ,can be influenced and significantly improved over time if supp

296、ortive policies are in place.Transparent and consistent GHG accounting,accompanied by robust verification processes,makes it possible to differentiate the performance of biofuels and to promote continuous GHG emission reductions,regardless of the feedstock or technology.Successful policies have been

297、 implemented in some jurisdictions for several years already notably Brazil and California,where carbon credits are allocated based on individual GHG performance.Prioritise support measures that have significant GHG reduction potential and can be quantified with low uncertainty.Such measures include

298、 energy efficiency improvements,methane capture from the treatment of manure and palm Carbon Accounting for Sustainable Biofuels Chapter 5.Conclusions and policy considerations PAGE|45 I EA.CC BY 4.0.oil mill effluent,improved biogas/biomethane plant design and CO2 removal through enhanced agricultu

299、ral practices or new industrial processes such as biogenic CO2 capture and storage.Foster the use of additional measures that have relatively strong emission reduction impacts but less certain quantification,and put appropriate verification procedures in place.These include soil carbon stock improve

300、ments,more sustainable fertiliser production and use,and the capture and utilisation of biogenic CO2 for other purposes(e.g.e-fuel production).Carbon intensity calculation methodologies and verification procedures should be adapted to reflect improvements in a transparent and consistent manner.Addre

301、ss indirect land use change(iLUC)concerns with risk-based approaches in the near term and strive to develop global land use policies.Although the potential for iLUC impacts is considerable,this parameter is the most complex and uncertain one to quantify.iLUC values cannot be measured quantitatively

302、or verified,only modelled.Moreover,different modelling runs can produce divergent iLUC estimates for the same biofuel pathway,not providing the consistency needed to formulate effective GHG reduction policies.Nevertheless,governments must take iLUC into account.Given concerns with respect to uncerta

303、inties and the risk of arbitrariness inherent in iLUC modelling,when policymakers address potential impacts they should consider alternatives such as risk-based approaches and direct measurements that are effective and broadly applicable for global iLUC analysis,instead of attempting to quantify ind

304、irect emissions in terms of gCO2-eq/MJ for a given biofuel pathway.In the short term,qualitative risk-based approaches that offer the additional possibility of complying with low-iLUC-risk requirements are a good option to address potential impacts and encourage improvement.In the long term,policies

305、 should evolve from modelling impacts to managing iLUC causes by enforcing everywhere direct land use regulations and supporting improved agricultural land management.At all times,governments should consider transitory measures to address exceptional food security concerns triggered by economic,geop

306、olitical or extreme weather conditions.Biofuel policies need to be designed to be flexible during periods of tightness in global agricultural markets,to avoid amplifying the size or duration of agricultural price spikes.Provide clear,consistent guidance on other sustainability criteria.Lifecycle GHG

307、 emissions are only one of several biofuel sustainability attributes to be considered when expanding biofuel production and use.Importantly,sustainability criteria should be the same for all biofuels and other sustainable fuels.A growing number of policies are also being designed to protect food and

308、 water security,monitor biodiversity,take other socioeconomic factors into account-including the Carbon Accounting for Sustainable Biofuels Chapter 5.Conclusions and policy considerations PAGE|46 I EA.CC BY 4.0.supply of secure and affordable energy-and mitigate impacts of land use changes beyond GH

309、G emissions.Stakeholder involvement Foster co-operation with agriculture policy developers for more effective holistic policies.Promoting improvements in agricultural management is crucial to boost agricultural efficiency and yields;increase land productivity(through the use of cover crops and multi

310、cropping);and enhance soil carbon stocks(by employing sustainable practices and applying organic soil improvers such as biochar and biofertilisers).Collaboration with the agriculture sector is essential to promote improvements in crop-based biofuel sustainability while addressing the broader issue o

311、f sustainability in agriculture in general.Include biofuels and relevant coproducts in broader policies to promote an integrated circular(bio)economy.Including biofuel coproducts and waste in support measures and fostering positive synergies with other sectors(e.g.agriculture and municipal waste tre

312、atment)can create a ripple effect in GHG emission savings from biofuel production.Biogenic CO2,digestate,oilseed cake,biorefinery residues and similar products are part of a circular(bio)economy that complements climate action with resource efficiency.Strengthen active international collaboration on

313、 carbon accounting,both within and among international organisations.Co-operation in scientific and technical areas remains dynamic,with data and model revisions,updates and developments ongoing.In the policy arena,key international collaborations are led by the International Civil Aviation Organiza

314、tion(ICAO)and more recently the International Maritime Organization(IMO),both regulatory bodies under the UN framework.Through these organisations,countries are building consensus to measure and verify internationally used and traded biofuels.In the medium and longer term,the approaches should conve

315、rge.Moreover,international collaboration on carbon accounting should be as inclusive as possible,reflecting the global diversity and potential of biofuel pathways,encompassing not only advanced economies but also emerging and developing ones.Support innovation in technologies that can provide negati

316、ve-emission fuels.Bold long-term commitments to achieve net zero(such as in the CORSIA and IMO schemes)will rely on negative-emissions to offset residual releases in hard-to-abate sectors.Biofuels have the potential to be coupled with carbon dioxide removal(CDR)technologies such as BECCS and biochar

317、 production.Unlocking the high-level emission reduction potential of biofuels will require innovation and regulatory incentives that reward accordingly.Carbon Accounting for Sustainable Biofuels Chapter 5.Conclusions and policy considerations PAGE|47 I EA.CC BY 4.0.Encourage consistent protocols and

318、 regulations for carbon accounting,including in voluntary carbon markets.Other initiatives not regulated by national legislation,such as international GHG protocol corporate accounting and reporting standards to drive corporate climate action,are also emerging in the wider portfolio of tools to redu

319、ce fuel emissions.Governments should recognise the increasing importance of the private sector and voluntary market programmes in helping accelerate low-emission-technology development.However,carbon accounting rules should be transparent and consistent with the best regulatory practices recognised

320、by international platforms(as outlined in this report)to avoid misalignment and,consequently,lower predictability for investors.Carbon Accounting for Sustainable Biofuels General annex PAGE|48 I EA.CC BY 4.0.General annex Parameters influencing the carbon intensity of biofuels Value chain element Pa

321、rameters relevant for GHG accounting Why are they relevant?Relative relevance What makes the accounting complex?Level of complexity Level of quantification uncertainty Verification of parameter calculation Biomass cultivation dLUC Can result in a change in cultivation site carbon stocks High Account

322、ing of the carbon inventory is based on regional/local parameters.Medium to high Medium Identification of LUC event;quantification of change in carbon stock on the land iLUC effects High High High Not quantified at the producer level but modelled for the system Fertilisation Nitrogen application and

323、 losses High Regional/local parameters influence the amount of N2O released;detailed actual data are required.Low to medium High Usually verified based on the amount of nitrogen applied at the cultivation stage,and on standardised assumptions Upstream emissions from synthetic nitrogen fertiliser pro

324、duction High Synthetic fertiliser production can create significant emissions if not based on renewable energy.Process-specific data are often not available.Low Low to medium Emissions are typically calculated based on emission factors from LCA databases and recognised sources.Carbon Accounting for

325、Sustainable Biofuels General annex PAGE|49 I EA.CC BY 4.0.Value chain element Parameters relevant for GHG accounting Why are they relevant?Relative relevance What makes the accounting complex?Level of complexity Level of quantification uncertainty Verification of parameter calculation Biomass cultiv

326、ation(continued)Use of agricultural machinery for cultivation and harvesting Diesel and gasoline use Low Can be estimated based on upstream emission factors for diesel and gasoline supply as well as for combustion processes Low Low Typically verified based on actual consumption data and emission fac

327、tors from recognised sources Soil carbon accumulation with improved agricultural practices Can result in a change in carbon stocks on the production site Medium to high Soil organic carbon has to be measured regularly Low Low Can be verified based on actual measurements of soil organic carbon over t

328、ime Use of residues for biofuel production Loss of soil organic carbon Agricultural residue use can deplete soil organic carbon Medium to high Regional/local production site data are necessary for individual assessments.Assessments should consider agricultural management effects on soil organic carb

329、on over a longer time frame.High Medium Can be verified based on actual measurements of soil organic carbon over time Avoided emissions in other product systems Using wastes as bioenergy feedstock can help avoid emissions from the conventional treatment of these materials(e.g.manure,POME)Medium Assu

330、mptions regarding avoided emissions are necessary.Medium Medium Can be verified based on standardised assumption and default values Carbon Accounting for Sustainable Biofuels General annex PAGE|50 I EA.CC BY 4.0.Value chain element Parameters relevant for GHG accounting Why are they relevant?Relativ

331、e relevance What makes the accounting complex?Level of complexity Level of quantification uncertainty Verification of parameter calculation Transport Transport distance and type of energy carrier Consumption of energy carriers and associated direct and upstream emissions Low to medium Can be estimat

332、ed based on energy consumed in the transport process,and on upstream emission factors for diesel and gasoline supply as well as for combustion.Low Low Typically verified based on actual consumption data and emission factors from recognised sources Biomass-to-biofuel conversion Energy consumption Ups

333、tream emissions from fossil and renewable energy chains Medium Process-specific energy consumption data as well as the sources of process energy have to be known.Low Low Typically verified based on actual consumption data and emission factors from recognised sources Auxiliary materials Upstream emissions from the production of chemicals Low Process-specific consumption of input materials has to be