Biofuels researchers question land use conversion studies

A number of prominent biofuels researchers have reacted strongly to the findings of two questionable papers published by Sciencexpress. The papers, authored by Timothy Searchinger and Joseph Fargione, reach debatable conclusions regarding the greenhouse gas emissions associated with potential land use changes caused by increasing biofuels demand.

The National Corn Growers Association (NCGA) believes the reactions from the scientific community to these two papers demonstrates that proper analysis of the causes and effects of land use change defies the simplistic and assumption-laden approaches taken by Searchinger and Fargione.

“There are no real, verifiable data in either of these papers on the land use changes that actually occur as more corn is processed to ethanol — hence these papers are not lifecycle analysis studies,” wrote Bruce Dale, a Michigan State University professor and expert in the field of biofuels lifecycle analysis, in a response to the article. “They are in fact highly speculative and uncertain scenarios for what might happen as a result of increased demand for corn grain.”

Michael Wang, of the U.S. Department of Energy’s (DOE) Argonne National Laboratory, and Zia Haq, of DOE’s Energy Efficiency and Renewable Energy, similarly responded that the issue of land use change requires much more thorough analysis.

“While scientific assessment of land use change issues is urgently needed in order to design policies that prevent unintended consequences from biofuel production, conclusions regarding the GHG emissions effects of biofuels based on speculative, limited land use change modeling may misguide biofuel policy development,” Wang and Haq wrote in a letter to Science.

Wang and Haq challenge a number of the specific assumptions used by Searchinger, including the assumption that corn ethanol production levels will be double what is actually required under the new Renewable Fuels Standard by 2015. Wang and Haq point out that the authors “…examined a corn ethanol production case that is not directly relevant to U.S. corn ethanol production in the next seven years.”

Kenneth Cassman, professor of agronomy and horticulture at the University of Nebraska, said a number of other critical factors must be considered in any attempts to model the effect of land use changes on the biofuels lifecycle.

“The ability to accurately predict the indirect impact of biofuel expansion on land use change cannot be evaluated in isolation from other major factors that influence land use change, which makes it a complex and challenging task,” Cassman said. “In fact, there has not been sufficient research linking the agriculture and energy sectors, and the other factors affecting land use, to allow accurate estimation of the indirect effect of biofuels alone.”

David Morris, vice-president of the Institute for Local Self-Reliance and author of an analysis released today on ethanol and land use changes, said “…the authors’ declarations that ethanol increases greenhouse gas emissions, a conclusion that has made headlines around the world, is not supported, and may be contradicted, by their own data.”

According to NCGA President Ron Litterer, the reaction from the scientific community to the findings of these papers demonstrates the need for much more careful evaluation and research of these issues.

“Stakeholders must demand that the best science is brought to bear in this debate,” Litterer said. “It is obvious from the lack of agreement on these issues that analyzing the impact of increased biofuels production on domestic and international land use change is a complex process and a relatively new area of study for the scientific community. The scientific community should be discouraged from rushing to judgment on these issues simply to satisfy political timetables.”

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