title: Accounting for indirect land-use change in the life cycle assessment of biofuel supply chains.
abstract: The expansion of land used for crop production causes variable direct and indirect greenhouse gas emissions, and other economic, social and environmental effects. We analyse the use of life cycle analysis (LCA) for estimating the carbon intensity of biofuel production from indirect land-use change (ILUC). Two approaches are critiqued: direct, attributional life cycle analysis and consequential life cycle analysis (CLCA). A proposed hybrid 'combined model' of the two approaches for ILUC analysis relies on first defining the system boundary of the resulting full LCA. Choices are then made as to the modelling methodology (economic equilibrium or cause-effect), data inputs, land area analysis, carbon stock accounting and uncertainty analysis to be included. We conclude that CLCA is applicable for estimating the historic emissions from ILUC, although improvements to the hybrid approach proposed, coupled with regular updating, are required, and uncertainly values must be adequately represented; however, the scope and the depth of the expansion of the system boundaries required for CLCA remain controversial. In addition, robust prediction, monitoring and accounting frameworks for the dynamic and highly uncertain nature of future crop yields and the effectiveness of policies to reduce deforestation and encourage afforestation remain elusive. Finally, establishing compatible and comparable accounting frameworks for ILUC between the USA, the European Union, South East Asia, Africa, Brazil and other major biofuel trading blocs is urgently needed if substantial distortions between these markets, which would reduce its application in policy outcomes, are to be avoided.
authors.affiliation: Life Cycle Associates, LLC, 985 Portola Road, Portola Valley, CA 94028, USA. sanchez@lifecycleassociates.com
authors.forename: Susan Tarka
authors.initials: ST
authors.lastname: Sanchez
authors.forename: Jeremy
authors.initials: J
authors.lastname: Woods
authors.forename: Mark
authors.initials: M
authors.lastname: Akhurst
authors.forename: Matthew
authors.initials: M
authors.lastname: Brander
authors.forename: Michael
authors.initials: M
authors.lastname: O'Hare
authors.forename: Terence P
authors.initials: TP
authors.lastname: Dawson
authors.forename: Robert
authors.initials: R
authors.lastname: Edwards
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Liska
authors.forename: Rick
authors.initials: R
authors.lastname: Malpas
mesh_terms: D056804:Biofuels / Q000600:supply & distribution*; D002245:Carbon Dioxide / Q000032:analysis*; D058572:Carbon Footprint / Q000706:statistics & numerical data*; D003247:Conservation of Natural Resources / Q000706:statistics & numerical data*; D004777:Environment; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D006802:Human Activities; D008962:Models, Theoretical; D006113:United Kingdom
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide