Under current EU law, member states must ensure at least 10% of fuel used in the transport sector is from renewable sources by 2020 – but MEPs voted last week to place a 7% cap on the amount of crop-based biofuel that can be used for transport.
Once thought to be an answer to environmental concerns associated with fossil fuels, a growing body of research suggests that crop-based biofuels may do more environmental harm than good. This latest study found that three models used to set government policy on biofuels in the US and Europe divert about 20% to 50% of net calories from corn and wheat to biofuels use, and do not replace them with planting elsewhere.
"Without reduced food consumption, each of the models would estimate that biofuels generate more emissions than gasoline," said Timothy Searchinger, first author on the paper and a research scholar at Princeton University.
The European Commission’s model to estimate emissions associated with biofuels use suggested the biggest reduction in emissions by using crops for fuel – but it also presumed a reduction in both food quantity and quality, due to replacing vegetables and oil crops with corn and wheat.
"Without these reductions in food quantity and quality, the [European] model would estimate that wheat ethanol generates 46% higher emissions than gasoline and corn ethanol 68% higher emissions," Searchinger said.
In addition, despite relying on less food consumption, policies to reduce emissions by diverting food crops to fuel so far have not built in safeguards to ensure the poorest consumers still have enough to eat.
"The impacts on food consumption result not from a tailored tax on excess consumption but from broad global price increases that will disproportionately affect some of the world's poor," Searchinger added.
“…Modellers need to make the trade-offs transparent so that policymakers can consider whether to seek climate mitigation through less food.”
Before becoming law, the proposed 7% EU limit on biofuels needs to pass a final vote from the European Parliament’s Environment Committee, due to take place on April 14.
Vol. 347 Iss. 6229 pp. 1420-1422 DOI: 10.1126/science.1261221
“Do biofuel policies seek to cut emissions by cutting food?”
Authors: T. Searchinger, R. Edwards, D. Mulligan, R. Heimlich, R. Plevin