Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 27 January 2006:
Vol. 311. no. 5760, pp. 506 - 508
DOI: 10.1126/science.1121416
Prev | Table of Contents | Next

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

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Sexual development in the industrial workhorse Trichoderma reesei.
V. Seidl, C. Seibel, C. P. Kubicek, and M. Schmoll (2009)
PNAS 106, 13909-13914
   Abstract »    Full Text »    PDF »
Amino acid digestibility of distillers dried grains with solubles, produced from sorghum, a sorghum-corn blend, and corn fed to growing pigs.
P. E. Urriola, D. Hoehler, C. Pedersen, H. H. Stein, and G. C. Shurson (2009)
J Anim Sci 87, 2574-2580
   Abstract »    Full Text »    PDF »
More Productive Than Maize in the Midwest: How Does Miscanthus Do It?.
F. G. Dohleman and S. P. Long (2009)
Plant Physiology 150, 2104-2115
   Abstract »    Full Text »    PDF »
Between Development and Environment: Uncertainties of Agrofuels.
T. E. Leon Sicard (2009)
Bulletin of Science Technology Society 29, 226-235
   Abstract »    PDF »
Greater Transportation Energy and GHG Offsets from Bioelectricity Than Ethanol.
J. E. Campbell, D. B. Lobell, and C. B. Field (2009)
Science 324, 1055-1057
   Abstract »    Full Text »    PDF »
Climate change and health costs of air emissions from biofuels and gasoline.
J. Hill, S. Polasky, E. Nelson, D. Tilman, H. Huo, L. Ludwig, J. Neumann, H. Zheng, and D. Bonta (2009)
PNAS 106, 2077-2082
   Abstract »    Full Text »    PDF »
Cellulosic ethanol production from AFEX-treated corn stover using Saccharomyces cerevisiae 424A(LNH-ST).
M. W. Lau and B. E. Dale (2009)
PNAS 106, 1368-1373
   Abstract »    Full Text »    PDF »
Cellodextrin and Laminaribiose ABC Transporters in Clostridium thermocellum.
Y. Nataf, S. Yaron, F. Stahl, R. Lamed, E. A. Bayer, T.-H. Scheper, A. L. Sonenshein, and Y. Shoham (2009)
J. Bacteriol. 191, 203-209
   Abstract »    Full Text »    PDF »
Comparative Genomics of Grasses Promises a Bountiful Harvest.
A. H. Paterson, J. E. Bowers, F. A. Feltus, H. Tang, L. Lin, and X. Wang (2009)
Plant Physiology 149, 125-131
   Full Text »    PDF »
Carbon neutral hydrocarbons.
F. S Zeman and D. W Keith (2008)
Phil Trans R Soc A 366, 3901-3918
   Abstract »    Full Text »    PDF »
Productivity and Nutrient Dynamics in Bioenergy Double-Cropping Systems.
A. H. Heggenstaller, R. P. Anex, M. Liebman, D. N. Sundberg, and L. R. Gibson (2008)
Agron. J. 100, 1740-1748
   Abstract »    Full Text »    PDF »
Energy production with agricultural biomass: environmental implications and analytical challenges.
J.-E. Petersen (2008)
Eur. Rev. Agric. Econ.
   Abstract »    Full Text »    PDF »
Metabolic engineering of a thermophilic bacterium to produce ethanol at high yield.
A. J. Shaw, K. K. Podkaminer, S. G. Desai, J. S. Bardsley, S. R. Rogers, P. G. Thorne, D. A. Hogsett, and L. R. Lynd (2008)
PNAS 105, 13769-13774
   Abstract »    Full Text »    PDF »
Progress in Metabolic Engineering of Saccharomyces cerevisiae.
E. Nevoigt (2008)
Microbiol. Mol. Biol. Rev. 72, 379-412
   Abstract »    Full Text »    PDF »
Climate change, biofuels and eco-social impacts in the Brazilian Amazon and Cerrado.
D. Sawyer (2008)
Phil Trans R Soc B 363, 1747-1752
   Abstract »    Full Text »    PDF »
Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change.
T. Searchinger, R. Heimlich, R. A. Houghton, F. Dong, A. Elobeid, J. Fabiosa, S. Tokgoz, D. Hayes, and T.-H. Yu (2008)
Science 319, 1238-1240
   Abstract »    Full Text »    PDF »
Net energy of cellulosic ethanol from switchgrass.
M. R. Schmer, K. P. Vogel, R. B. Mitchell, and R. K. Perrin (2008)
PNAS 105, 464-469
   Abstract »    Full Text »    PDF »
Molecular Breeding to Enhance Ethanol Production from Corn and Sorghum Stover.
W. Vermerris, A. Saballos, G. Ejeta, N. S. Mosier, M. R. Ladisch, and N. C. Carpita (2007)
Crop Sci. 47, S-142-S-153
   Abstract »    Full Text »    PDF »
Maize Biomass Yield and Composition for Biofuels.
K. S. Dhugga (2007)
Crop Sci. 47, 2211-2227
   Abstract »    Full Text »    PDF »
Biofuels in Brazil: An Overview.
L. L. Nass, P. A. A. Pereira, and D. Ellis (2007)
Crop Sci. 47, 2228-2237
   Abstract »    Full Text »    PDF »
Feedstock Crop Genetic Engineering for Alcohol Fuels.
M. B. Sticklen (2007)
Crop Sci. 47, 2238-2248
   Abstract »    Full Text »    PDF »
Potential for Enhanced Nutrient Cycling through Coupling of Agricultural and Bioenergy Systems.
R. P. Anex, L. R. Lynd, M. S. Laser, A. H. Heggenstaller, and M. Liebman (2007)
Crop Sci. 47, 1327-1335
   Abstract »    Full Text »    PDF »
Response to Comment on "Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass".
D. Tilman, J. Hill, and C. Lehman (2007)
Science 316, 1567c
   Abstract »    Full Text »    PDF »
Impact of High-Lignin Fermentation Byproduct on Soils with Contrasting Organic Carbon Content.
J. M.-F. Johnson, B. S. Sharratt, D. C. Reicosky, and M. Lindstrom (2007)
Soil Sci. Soc. Am. J. 71, 1151-1159
   Abstract »    Full Text »    PDF »
Energy: The Issue of the 21st Century.
A. M. Macfarlane (2007)
Elements 3, 165-170
   Abstract »    Full Text »    PDF »
A Two-Component System Regulates the Expression of an ABC Transporter for Xylo-Oligosaccharides in Geobacillus stearothermophilus.
S. Shulami, G. Zaide, G. Zolotnitsky, Y. Langut, G. Feld, A. L. Sonenshein, and Y. Shoham (2007)
Appl. Envir. Microbiol. 73, 874-884
   Abstract »    Full Text »    PDF »
Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass.
D. Tilman, J. Hill, and C. Lehman (2006)
Science 314, 1598-1600
   Abstract »    Full Text »    PDF »
Enzyme-microbe synergy during cellulose hydrolysis by Clostridium thermocellum.
Y. Lu, Y.-H. P. Zhang, and L. R. Lynd (2006)
PNAS 103, 16165-16169
   Abstract »    Full Text »    PDF »
From the Cover: Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels.
J. Hill, E. Nelson, D. Tilman, S. Polasky, and D. Tiffany (2006)
PNAS 103, 11206-11210
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)