Environmental and resource burdens associated with world biofuel production out to 2050: footprint components from carbon emissions and land use to waste arisings and water consumption.
Environmental or 'ecological' footprints have been widely used in recent years as indicators of resource consumption and waste absorption presented in terms of biologically productive land area [in global hectares (gha)] requiredper capitawith prevailing technology. In contrast, 'carbon footprints' are the amount of carbon (or carbon dioxide equivalent) emissions for such activities in units of mass or weight (like kilograms per functional unit), but can be translated into a component of the environmental footprint (on a gha basis). The carbon and environmental footprints associated with the world production of liquid biofuels have been computed for the period 2010-2050. Estimates of future global biofuel production were adopted from the 2011International Energy Agency(IEA) 'technology roadmap' for transport biofuels. This suggests that, althoughfirst generation biofuelswill dominate the market up to 2020, advanced orsecond generation biofuelsmight constitute some 75% of biofuel production by 2050. The overall environmental footprint was estimated to be 0.29 billion (bn) gha in 2010 and is likely to grow to around 2.57 bn gha by 2050. It was then disaggregated into various components: bioproductive land, built land, carbon emissions, embodied energy, materials and waste, transport, and water consumption. This component-based approach has enabled the examination of theManufacturedandNatural Capitalelements of the 'four capitals' model of sustainability quite broadly, along with specific issues (such as the linkages associated with the so-called energy-land-water nexus). Bioproductive land use was found to exhibit the largest footprint component (a 48% share in 2050), followed by the carbon footprint (23%), embodied energy (16%), and then the water footprint (9%). Footprint components related to built land, transport and waste arisings were all found to account for an insignificant proportion to the overall environmental footprint, together amounting to only about 2.
Department of Mechanical Engineering University of Bath Bath BA2 7AY UK; Institute for Sustainable Energy and the Environment (ISEE) University of Bath Bath BA2 7AY UK.
Geoffrey P
0000-0002-0922-8728
GP
Hammond
Department of Mechanical Engineering University of Bath Bath BA2 7AY UK.
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B
Li
carbon emissions; embodied energy; energy–land–water nexus; environmental footprints; land use; sustainability; transport; waste arisings; water consumption; world biofuel production