Study favors trees over biofuels

Restoring forests and savannahs on unused cropland would do more to limit global warming than growing so-called energy crops for biofuels on those tracts, according to a new study by researchers at the University of Leeds.

Over a 30-year period, reforestation would remove two to nine times more CO2 from the air than would be saved by using biofuels instead of gasoline, according to the researchers, who published their findings in the academic journal Science. Clearing existing forests to grow sugar beet, wheat, corn, rapeseed and other crops for ethanol production could actually increase global warming, the Leeds researchers said.

“If the point of biofuels policies is to limit global warming, policy makers may be better advised in the short term to focus on increasing the efficiency of fossil fuel use, to conserve existing forests and savannahs, and to restore natural forest and grassland habitats on cropland that is not needed for food,” said Renton Righelato, one of the two authors of the study.

Long-term, the study recommends continued work on turning biomass from woody material into fuels, as well as development of vehicles that do not emit CO2.

The full text of “Carbon Mitigation by Biofuels or by Saving and Restoring Forests?” is available at www.sciencemag.org.