Ethanol isn’t as green as you might think, researchers say
The study, Environmental outcomes of the US Renewable Fuel Standard, will be published in the March issue of Proceedings of the National Academy of Sciences of the United States of America. The work was supported by the U.S. Deptartment of Energy and the National Wildlife Federation, among others. The Bloomberg news service noted that the National Wildlife Federation is a vocal critic of the RFS.
'Precarious' conclusions, shouts trade group
The Renewable Fuels Association, which aims to expand demand for American-made biofuels, said the RFS is the "single most successful clean fuels policy in the U.S." The group said ethanol has saved Americans money, reduced the country's dependence on foreign fuels, and supported job growth.
The Renewable Fuels Association accused the researchers of "precariously" connecting a series of "worst-case scenarios." The trade group's president and CEO, Geoff Cooper, said that the RFA previously met with the study's author and offered to collaborate on research but never heard back.
RFA released a line-by-line rebuttal of the University of Wisconsin study. The group references a study released in 2021 by authors linked to Harvard University and the Massachusetts Institute of Technology that found well-to-wheel greenhouse gas emissions of corn ethanol to be 40% lower than gasoline produced from crude oil.
The authors of Carbon intensity of corn ethanol in the United States attributed declining carbon intensity to improved farming practices, more efficient use of natural gas, and an increasing share of electric generation by ethanol refineries.