America’s ethanol fuel mandate, promoted in part as a way to reduce greenhouse gas emissions from fossil fuels, “actually leads to a net increase” in such releases by “hundreds of millions of tons,” Climate Central reports, citing researchers at the University of Minnesota, St. Paul.
The United States created its Renewable Fuel Standard (RFS) in 2005. It requires that gasoline sold in the country be blended with mandated volumes of “conventional biofuel, advanced biofuel, [or] cellulosic biofuel.” The mandate was meant to reduce America’s dependence on imported oil, but has also been promoted by farmers as a contribution to reducing the country’s greenhouse gas emissions.
About 10% of the gasoline sold in the U.S. now comes from one of the listed biofuels, which possess between 40 and 80% of the “emission intensity” of petroleum-based fuels, according to the researchers’ paper published in the journal Energy Policy.
Economic “rebound effects”, however, have led to the opposite result, they say. “Biofuels contain less energy than fossil fuels, so more must be burned to travel the same number of miles,” Climate Central writes. “And increasing the production of an alternative fuel helps make fossil fuels cheaper,” tempering the reductions in fossil fuel demand—the so-called fuel rebound effect.
Meanwhile, fossil fuels are being burned to produce ethanol. As a result, the outlet says, “for every three gallons of corn ethanol that’s being burned, Americans will avoid burning just one gallon of gasoline made from crude.”
“The fuel rebound effect is so strong, and the climate benefits of the biofuels are so small, especially for corn ethanol, that emissions increase,” explained research lead Jason Hill. Between 2006, the first year of the mandate, and 2022, his team estimates the RFS it will generate 749 million tonnes of additional emissions.
The U.S. Environmental Protection Agency, which reviewed the Minnesota study and according to Climate Central “did not disputes its findings,” launched its own investigation a year ago into whether the climate benefits claimed for ethanol add up.