Biofuel carbon emissions ‘higher than expected’ – study
Last updated on 24 March 2014, 12:35 pm
Green credentials of biofuels face further scrutiny after study shows indirect emissions more than previous estimates
By Gerard Wynn
The indirect carbon emissions from producing biofuels from food crops are much higher than previously calculated, a European Union study has found.
The study may be bad news for the European biofuel industry, already suffering from doubts over continued EU support.
Two years ago, the European Unionâs executive Commission proposed to halve the original mandatory biofuel blending target, concerned about the possible impact on food prices.
The European Commission also proposed to include a wider definition for carbon emissions.
That wider definition would include indirect emissions as a result of land use change, such as deforestation caused by planting more crops to produce biofuels.
That would add to direct emissions from planting and harvesting crops such as maize and oil seeds, and refining them into biofuel.
Two years on, EU member states are yet to agree on the Commissionâs proposals.Â The EUâs research arm, the Joint Research Centre (JRC), this week published new estimates for indirect land use change (ILUC) emissions.
The new study found ILUC emissions were 3% to 62% higher, under new assumptions, compared with a previous study which had informed the original European Commission proposals.
The JRC report was carried out in collaboration with the Washington-based International Food Policy Research Institute (IFPRI).
Testing several new assumptions, it found that the original IFPRI study had assumed higher wheat yields in 2020 than most others.
Lower yields led to a 15% hike in calculated ILUC emissions for wheat-based ethanol, because lower yields implied that more land must be ploughed up to produce biofuels.
In addition, the previous study had assumed that the farmed area for cereals could be expanded by displacing oil seeds including olives, which are not in fact so flexible, being a perennial rather than an annual crop.
Making the expansion of the farmed area less flexible raised ILUC emissions by 0-29%, depending on the crop.
Finally, the new JRC study removed the assumption that biofuels would cause food consumption to drop, an undesirable outcome for poor people.
The impact on ILUC emissions of fixing consumption varied according to the crop, from a 20% decrease for sugar beet to a 30% increase for soy beans.
The overall, combined effect from the three changes was a 3% to 62% increase in ILUC emissions.
In 2012 the European Commission proposed to amend both the fuel quality and renewable energy directives which regulate biofuel production.
The proposals would require biofuels to make bigger savings in direct greenhouse gas emissions than previously, compared with burning conventional crude oil-based fuels.
The Commission also proposed to require member states to report the ILUC emissions of crop-based biofuels, and said it would decide in 2017 whether the science was sufficiently robust to take ILUC emissions into account when calculating carbon savings.
Those proposals were in addition to halving the 2020 biofuel blending target, to 5% of all transport fuel from 10%, for crop-based fuels.
EU member states have since failed to agree on whether to adopt the proposals, but the latest study will do nothing to reassure the industry.