Panel gives mixed review to U.S. biofuel rules

EPA ordered the independent review in May, when it proposed regulations for expansion of U.S. biofuel output. They would require biofuels to show an overall reduction in greenhouse gases, including land that may be converted to crops overseas.

Growth Energy, an ethanol industry group, said the peer review showed EPA's estimates were not reliable. It said Congress should eliminate indirect land use change from EPA regulations or order an Academy of Sciences study of the concept.

Rep. Collin Peterson, Democrat of Minnesota, said the peer review proved EPA used "incomplete and unreliable models" to link farming decisions overseas and U.S. biofuel output. Peterson, the House Agriculture Committee chairman, played a leading role in a House vote to require a five-year study of indirect land use change.

The four scientists who examined EPA's models of U.S. and international land use agreed EPA's use of elements of two land-use models was reasonable and preferable to using a single, global model, said EPA in a summary of the review.

The scientists said the global model did not produce data with sufficient detail. On the other hand, they suggested ways to improve the models that EPA used in part, such as more attention to U.S. forests as a source of new cropland.

One reviewer, Michael Wang of Argonne National Laboratory, "questioned whether the modeling capabilities currently available in the field are sufficient to generate results for use in development of regulation," said EPA, summarizing responses to the question of whether there were better ways to estimate agricultural impacts.

EPA wants to implement the new biofuel regulations this year.

(Reporting by Charles Abbott; Editing by David Gregorio)