Carbon and Environmental Footprinting of Global Biofuel Production

What is it about?

The environmental and carbon footprints of the global biofuel production have been determined on both a historic timescale and in accordance with international projections. Methodologies employed were consistent with those developed by the Global Footprint Network and related bodies. Annual environmental footprints have been computed from a baseline of 2007–2009 and projected forward to 2019. Estimates of future global biofuel production were adopted from OECD–FAO (and effectively US DOE) projections. In order to determine the footprints associated with these biofuel resources, the overall environmental footprint was disaggregated into bioproductive land, carbon emission (effectively cf), embodied energy, materials and waste, transport, and water components. The global carbon footprint of biofuels was estimated to be 0.248 billion (bn) global hectares (gha) in 2010; arising to 0.449 bn gha by 2019. The total environmental footprint for the global production of biofuels was estimated to be 0.720 billion gha for 2010; rising to 1.242 bn gha by 2019. Bioproductive land use proved to give rise to the highest element of the footprint, with the ‘carbon footprint’ as the next highest, followed by the water footprint, and then the transport component. The waste, built land, and embodied energy components contributed an insignificant amount to the total environmental footprint.These mainly reflect the impact of first generation biofuels (FGB) as second generation technologies will have a relatively low output up to 2020.

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Why is it important?

Transport underpins the mobility of people around the world, but presently accounts for around 20% of global anthropogenic carbon dioxide (CO2) emissions [4,5]: an unwanted side-effect. The adoption of liquid biofuels in the transport sector has therefore been seen, particularly by the EU, as a means for meeting climate change mitigation targets, enhancing regional energy or fuel security, and contributing to rural development (through the provision of an alternative source of income in otherwise depressed agricultural communities). Biomass can be converted into premium-quality liquid biofuels and biochemicals. Bioethanol and biodiesel also hold out the prospect of retaining the existing transport infrastructure (e.g., refuelling or ‘petrol’ stations), in contrast to other low carbon options such as hydrogen-fuelled or electric vehicles. This has significant benefits in terms of limiting capital expenditure and the potential speed of take-up. But the deployment of biofuels has been linked to significant impacts in terms of direct and indirect land use change (LUC and iLUC), loss of biodiversity and eco-system services, and competition with food production. First generation biofuels (FGB), for example, are produced primarily from food crops, and are limited by their inability to achieve targets for oil-product substitution (without threatening food supplies and biodiversity) and for GHG reductions. In contrast, more advanced or second generation biofuels (SGB) are generally produced from agricultural or crop ‘wastes’ (such as straw) and from non-food energy crops, which significantly reduces these negative impacts. Potential feedstocks and conversion routes therefore need to be assessed against the full range of sustainability considerations and over the full life-cycle of the biofuel supply chain: from ‘field-to-(‘gas’ or petrol station) forecourt’ or ‘seed-to-wheel’. Only in this way will the true consequences of a given biofuel – environmental, economic and social – be determined.

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