Two studies say expanding biofuels production worldwide will raise greenhouse emissions

Two recent studies say increased biodiesel and ethanol production worldwide could "increase greenhouse gas emissions more than than the fossil fuels they displace because of the impact of converting forests and grasslands worldwide to crop production," reports Philip Brasher of the Washington bureau of The Des Moines Register.

Earlier studies have suggested biofuel use could reduce emissions by 20 percent compared to gasoline, but they did not consider the impact of clearing forest and other land for crops. These new studies — one released by Science magazine today, and the other from the Nature Conservancy and the University of Minnesota — focus on the effects of such land conversion as well as the use of switchgrass and palm oil, Brasher explains.

The Science study, which included researchers from Iowa State University, "said that the grass-derived fuel results in 50 percent higher carbon emissions than gasoline because additional corn acreage would have to be found somewhere else," Brasher writes. The second study said that "converting rain forests to palm oil production for biodiesel can release as much as 420 times more carbon dioxide than is saved by displacing petroleum diesel."

Biofuel production can cut carbon dioxide emissions when abandoned farmland is used for growing or when corn stover and similar waste products are used as feedstock. (Read more)