Tuesday, November 11, 2008

EPA planning to calculate land-use changes in gauging greenhouse-gas impact of biofuels

Already under fire for making food more expensive, biofuels, "long touted as green, are being criticized as bad for the planet," reports Stephen Power in The Wall Street Journal.

Following publication of a study in the February issue of the journal Science, the Environmental Protection Agency has indicated it plans to measure each biofuel's emissions based partly on the ripple effect that its production in the U.S. can have overseas. "Environmental groups say disclosing the emissions levels associated with land-use change caused by biofuels is critical to determining which fuels will best help the U.S. reduce its dependence on oil," Power notes.

The study found that U.S. production of ethanol from corn releases 93 percent more greenhouse gases than would be released by producing gasoline, "when expected world-wide land-use changes are taken into account," Power notes. "Applying the same methodology to biofuels made from switchgrass grown on soil diverted from raising corn, the study found that greenhouse-gas emissions would rise by 50 percent."

Previous studies found that substituting biofuels for gasoline reduces greenhouse gases, but they "generally didn't account for the carbon emissions that occur as farmers world-wide respond to higher food prices and convert forest and grassland to cropland," Power reports. "But some scientists and many biofuel proponents have challenged the Science study, saying it relied on unrealistic assumptions." (Read more)

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