U.S. corn-based ethanol worse for the climate than gasoline, study finds
By Leah Douglas, Reuters | February 14, 2022
Corn-based ethanol, which for years has been mixed in huge quantities into gasoline sold at U.S. pumps, is likely a much bigger contributor to global warming than straight gasoline, according to a study published Monday.
The study, published in the Proceedings of the National Academy of Sciences, contradicts previous research commissioned by the U.S. Department of Agriculture (USDA) showing ethanol and other biofuels to be relatively green.
President Joe Biden’s administration is reviewing policies on biofuels as part of a broader effort to decarbonize the U.S. economy by 2050 to fight climate change.
“Corn ethanol is not a climate-friendly fuel,” said Dr. Tyler Lark, assistant scientist at University of Wisconsin-Madison Center for Sustainability and the Global Environment and lead author of the study.
The research, which was funded in part by the National Wildlife Federation and U.S. Department of Energy, found that ethanol is likely at least 24% more carbon-intensive than gasoline due to emissions resulting from land use changes to grow corn, along with processing and combustion.
Geoff Cooper, president and CEO of the Renewable Fuels Association, the ethanol trade lobby, called the study “completely fictional and erroneous,” arguing the authors used “worst-case assumptions [and] cherry-picked data.”
Under the U.S. Renewable Fuel Standard (RFS), a law enacted in 2005, the nation’s oil refiners are required to mix some 15 billion gallons of corn-based ethanol into the nation’s gasoline annually. The policy was intended to reduce emissions, support farmers, and cut U.S. dependence on energy imports.