Scientists from the Department of Energy’s Argonne National Laboratory and others around the country are calling into question the assumptions and conclusions of researchers who published their findings last week in Science.

Dr. Michael Wang of Argonne’s Transportation Technology R&D Center and Zia Haq of the DOE’s Office of Biomass Program sent a letter commenting on the studies, which generated headlines this week that biofuels are worse for global warming than fossil fuels.

Wang and Haq note that the study authors “used the GREET model developed by one of us at Argonne National Laboratory in their study.” However, the model uses outdated data and the study authors used a worst-case scenario approach.

Searchinger et al. modeled a case in which U.S. corn ethanol production increased from 15 billion gallons a year to 30 billion gallons a year by 2015. However, in the 2007 Energy Independence and Security Act (EISA), Congress established an annual corn ethanol production cap of 15 billion gallons by 2015. Congress established the cap — based on its awareness of the resource limitations for corn ethanol production — to help prevent dramatic land use changes. Thus, Searchinger et al. examined a corn ethanol production case that is not directly relevant to U.S. corn ethanol production in the next seven years.

Wang and Haq conclude, “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.”

The full text of the Argonne response letter can be found here.

The Renewable Fuels Association notes others in the scientific community who are questioning the studies.

Dr. Lou Honary, Director of the National Ag-Based Lubricants Center at the University of Northern Iowa, notes in a letter to the editor of the New York Times:

“In technology forecasting, some predictions can be self-defeating just as others can become self-fulfilling. In this case, both reports and their projections of a pending global disaster due to inappropriate land use are overly simplistic and do not take into account many other related factors. The assumption that corn and soybeans are and will continue to be the long term source of raw materials for biofuels production is incorrect, and it is this assumption that leads us to make self-defeating projections.

Joining Dr. Honary in his caution about putting too much credibility in the conclusions of the reports is Dr. Bruce Dale, Chairman of the Department of Chemical Engineering and Materials Science at Michigan State University; and Chris Somerville, director of the BP-funded Energy Biosciences Institute at the University of California, Berkeley, in a Cleantech.com article.

Somerville said one of the papers’ fundamental claims, that using land for biofuels will inevitably lead to the expansion of agriculture, doesn’t have a historical precedent. “In the case of cereals, over the last 50 years there’s been a doubling of demand, but there’s not been an expansion of acreage,” he said to Cleantech.com.
“Expanding demand has generally not led to a corresponding increase in demand for land use. I would say it’s a speculative response for a speculative paper.”