New Study Weighs Impacts of Corn Ethanol

New Study Weighs Impacts of Corn Ethanol

A new study from the University of Minnesota finds that biofuel made from corn can be as harmful to the environment as gasoline, and that the combined costs to climate-change and health exceed that of gas.

The study published in the Proceedings of the National Academy of Sciences also finds that the benefits of second-generation cellulosic ethanol, made from grasses and crops like jatropha, are markedly greater than corn ethanol or gasoline.

The research is the latest in the debate of the merits of first generation biofuel made from corn.

According to the study, for each billion ethanol-equivalent gallons of fuel produced and combusted in the U.S., the combined climate-change and health costs are $469 million for gasoline, $472 million to $952 million for corn ethanol depending on biorefinery heat source — natural gas, corn stover or coal — and technology, but only $123 million to $208 million for cellulosic ethanol depending on feedstock — prairie biomass, Miscanthus, corn stover, or switchgrass.

The study by Jason Hill, Stephen Polasky, Erik Nelson, David Tilman, Hong Huo, Lindsay Ludwig, James Neumann, Haochi Zheng and Diego Bonta is the first to examine and monetize lifecycle climate change and health effects from greenhouse and fine particulate matter emissions from gasoline, corn ethanol and cellulosic ethanol.

"Our work highlights the need to expand the biofuels debate beyond its current focus on climate change to include a wider range of effects such as their impacts on air quality," Hill, a resident fellow in the University of Minnesota's Institute on the Environment and lead author of the report, told

"To understand the environmental and health consequences of biofuels, we must look well beyond the tailpipe to how and where biofuels are produced."

A study from the University of Nebraska-Lincoln, published in January in the Journal of Industrial Ecology, holds that corn ethanol directly emits an average of 51 percent less greenhouse gas than gas — an amount three times the reduction reported in earlier research.

Hill told the New York Times that the Nebraska research did not consider as many factors as the work of his team. He also said the findings of the studies were compatible, the times reported.