Greenhouse Gas Impacts of Ethanol from Iowa Corn: Life Cycle Analysis Versus System-Wide Accounting
Life cycle analysis (LCA) is the standard approach used to evaluate the greenhouse gas (GHG) benefits of biofuels. However, it is increasingly recognized that LCA results do not account for some impacts-including land use changes-that have important implications on GHGs. Thus, an alternative accounting system that goes beyond LCA is needed. In this paper, we contribute to the literature by laying out the basics of a system-wide accounting (SWA) method that takes into account all potential changes in GHGs resulting from biofuel expansion. We applied both LCA and SWA to assess the GHG impacts of ethanol based on Iowa corn. Growing corn in rotation with soybeans generated 35% less GHG emissions than growing corn after corn. Based on average corn production, ethanol's GHG benefits were lower in 2007 than in 2006 because of an increase in continuous corn in 2007. When only additional corn was considered, ethanol emitted about 22% less GHGs than gasoline. Results from SWA varied with the choice of baseline and the definition of geographical boundaries. Using 2006 as a baseline and 2007 as a scenario, corn ethanol's benefits were about 20% of the emissions of gasoline. If we expand geographical limits beyond Iowa, but assume the same emission rates for soybean production and land use changes as those in Iowa, then corn ethanol generated more GHG emissions than gasoline. These results highlight the importance of boundary definition for both LCA and SWA.
|Date of creation:||01 Feb 2008|
|Date of revision:|
|Publication status:||Published in Biomass and Bioenergy, June 2010, vol. 34 no. 6, pp. 912-921|
|Contact details of provider:|| Postal: |
Phone: +1 515.294.6741
Fax: +1 515.294.0221
Web page: http://www.econ.iastate.edu
More information through EDIRC
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- David A. Hennessy, 2006.
"On Monoculture and the Structure of Crop Rotations,"
American Journal of Agricultural Economics,
Agricultural and Applied Economics Association, vol. 88(4), pages 900-914.
- David A. Hennessy, 2004. "On Monoculture and the Structure of Crop Rotations," Center for Agricultural and Rural Development (CARD) Publications 04-wp369, Center for Agricultural and Rural Development (CARD) at Iowa State University.
- Hennessy, David A., 2004. "On Monoculture and the Structure of Crop Rotations," Staff General Research Papers 12004, Iowa State University, Department of Economics.
- Delucchi, Mark, 2004. "Conceptual and Methodological Issues in Lifecycle Analyses of Transportation Fuels," Institute of Transportation Studies, Working Paper Series qt8n77n6z7, Institute of Transportation Studies, UC Davis.
- Baker, Mindy L. & Babcock, Bruce A., 2008. "Value maximization from corn fractionation: feed, greenhouse gas reductions, and cointegration of ethanol and livestock," Transition to a Bio Economy Conferences, Integration of Agricultural and Energy Systems Conference, February 12-13, 2008, Atlanta, Georgia 48714, Farm Foundation.
When requesting a correction, please mention this item's handle: RePEc:isu:genres:12871. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Curtis Balmer)
If references are entirely missing, you can add them using this form.