Nearly 80% of U.S. farmland would need to grow corn for ethanol to meet current biofuel targets with existing technology, finds study; authors call for realistic bioenergy targets that would not compete with food production
March 1, 2012
– A new study by The University of Montana and its partners suggests nearly 80 percent of current U.S. farmland would need to be devoted to growing corn for ethanol to meet current biofuel production targets with existing technology.
The study, “Bioenergy Potential of the United States Constrained by Satellite Observations of Existing Productivity,” was published recently in Environmental Science & Technology, a journal of the American Chemical Society.
Lead author W. Kolby Smith, a doctoral student in UM’s Numerical Terradynamic Simulation Group, said the federal 2007 Energy Independence and Security Act set a goal of increasing U.S. biofuel production from 40 billion to 136 billion gallons of ethanol by 2022.
“We learned that gaps exist in the ability to establish realistic targets for biofuel production, which the law fills with assumptions about technology developments and the availability and productivity of farmland,” Smith said. “To establish more accurate estimates, we used satellite data about the climate, plant cover and usable land to determine how much biofuel the U.S. could produce.”
The satellite analysis found that to meet goals using current technology, farmers would either need to plant biofuel crops on 80 percent of their farmed land or plant biofuel crops on 60 percent of the land currently used to raise livestock. The authors reported that both options would significantly reduce the amount of food U.S. farmers produce. They also noted that research shows increased farming could lead to more polluted freshwater and accelerate global climate change.
The other UM authors were Cory Cleveland, an assistant professor of soil sciences, and Steve Running, NTSG director and Regents Professor of Ecology. Other contributors were Sasha Reed of the U.S. Geological Survey in Moab, Utah, and Norman Miller of the Lawrence Berkeley National Laboratory in Berkeley, Calif.
“While we encourage the appropriate use of agricultural residues, forest slash and beetle-killed trees for bioenergy, the nation needs realistic targets of the capacity for bioenergy production that would not compete with food production,” Running said. “Additionally, bioenergy may be more efficiently used for electric power production instead of liquid fuels.”
The paper is available online at http://pubs.acs.org/doi/abs/10.1021/es203935d.