Biofuels: Worse for Earth Than Oil?

Feb. 8, 2008 -- Clearing raw land to produce biofuels actually contributes to global warming by emitting large amounts of greenhouse gases into the atmosphere, researchers have warned.

Carbon dioxide (CO2) emissions from new croplands carved into rainforests, savannas, wetlands or grasslands would easily surpass the overall amount of CO2 emissions reduced through the use of biofuels, according to a report in the Feb. 8 edition of Science.

"If you're trying to mitigate global warming, it simply does not make sense to convert land for biofuels production," said Joe Fargione, a founder of private environment protection agency the Nature Conservancy and co-author of the study.

"All the biofuels we use now cause habitat destruction, either directly or indirectly," he said.

"Global agriculture is already producing food for six billion people. Producing food-based biofuel, too, will require that still more land be converted to agriculture."

Converting land to grow corn, sugar cane or soy beans -- crops used in the production of biofuels -- creates a "biofuel carbon debt" by releasing 17 to 420 times as much CO2 into the atmosphere as the greenhouse gas reductions which the biofuels provide by displacing fossil fuels.

Carbon is stored in dead trees and plants as well as in the soil, and naturally seeps into the atmosphere in the form of CO2. Converting native habitats to cropland increases the release of CO2 into the air, the report said.

It would take years, and in some cases centuries, before biofuels derived from crops on converted land would lead to a net reduction of greenhouse gases, according to the report.