Biofuels do harm, aren't they?

Biofuels based on ethanol, vegetable oil and other renewable sources are increasingly popular with government and environmentalists as a way to reduce fossil fuel dependence and limit greenhouse gas emissions.

Biofuels have been hailed as a green alternative to oil by some, but in the US, where there are massive plants converting maize (corn), it has been criticised for making food more expensive and being environmentally unfriendly.

But new research led by a biologist at the University of Washington, Bothell, shows that some of the most popular current biofuel stocks might have exactly the opposite impacts than intended. The authors of a paper published in the June issue of the journal Conservation Biology offer a dozen policy recommendations to promote sustainability and biodiversity in biofuel production.

The study looked at factors such as the energy needed to produce a renewable fuel source compared with how much energy is produced, the impact on soil fertility and effects on food supply when fuels based on crops such as corn and soybeans are mixed with fossil fuels. Based on those factors, the authors determined that corn-based ethanol is the worst alternative overall.

"It's foolish to say we should be developing a particular biofuel when that could mean that we’re just replacing one problem with another," said lead author Martha Groom of the UW Bothell. Co-authors are Elizabeth Gray of The Nature Conservancy and Patricia Townsend of the UW Seattle.

Britain produces about 55,000 tonnes a year of bioethanol, which is added to petrol, mostly from sugarbeet, and 75,000 tonnes of biodiesel, added to diesel, from tallow and rape, soya and palm oil. Two million tonnes a year would be needed to meet the 5 per cent target.