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Science 27 January 2006:
Vol. 311. no. 5760, pp. 506 - 508
DOI: 10.1126/science.1121416
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Reports

Ethanol Can Contribute to Energy and Environmental Goals

Alexander E. Farrell,1* Richard J. Plevin,1 Brian T. Turner,1,2 Andrew D. Jones,1 Michael O'Hare,2 Daniel M. Kammen1,2,3

To study the potential effects of increased biofuel use, we evaluated six representative analyses of fuel ethanol. Studies that reported negative net energy incorrectly ignored coproducts and used some obsolete data. All studies indicated that current corn ethanol technologies are much less petroleum-intensive than gasoline but have greenhouse gas emissions similar to those of gasoline. However, many important environmental effects of biofuel production are poorly understood. New metrics that measure specific resource inputs are developed, but further research into environmental metrics is needed. Nonetheless, it is already clear that large-scale use of ethanol for fuel will almost certainly require cellulosic technology.

1 Energy and Resources Group, University of California, Berkeley, CA 94720–3050, USA.
2 Goldman School of Public Policy, University of California, Berkeley, CA 94720–3050, USA.
3 Renewable and Appropriate Energy Laboratory, University of California, Berkeley, CA 94720–3050, USA.

* To whom correspondence should be addressed. E-mail: aef{at}berkeley.edu

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