Scientists Find Corn Ethanol Reduces Carbon Emissions by Nearly 50%

By Ken Colombini

A comprehensive new study by scientists from Harvard University, Tufts University and Environmental Health & Engineering Inc. shows that using corn ethanol in place of gasoline reduces greenhouse gas emissions by almost half. The “central best estimate” of corn ethanol’s carbon intensity is 46% lower than the average carbon intensity of gasoline, according to the study’s authors, with some corn ethanol in the market today achieving a 61% reduction. The study credits recent efficiency improvements and the adoption of new technologies for the steady reduction in the lifecycle carbon intensity of corn ethanol. The new study will be published in an upcoming volume of Environmental Research Letters, a well-respected academic journal.

“This new study provides further validation that ethanol is a highly effective tool for decarbonizing liquid transportation fuels and significantly reducing greenhouse gas emissions from the transportation sector,” said Renewable Fuels Association President & CEO Geoff Cooper. “And with ethanol, we don’t have to wait and hope for technological and economic breakthroughs. It’s here today at a low cost and already has a proven track record. Ethanol can and should be allowed to do more to contribute to the fight against climate change, and that starts by breaking down the barriers to higher blends like E15, E30, and flex fuels like E85. As President Biden’s administration and the new Congress consider actions and policies to address climate change, we encourage them to examine the best available science and properly account for the critical role ethanol and other renewable fuels can play in securing immediate GHG reductions.”

Cooper pointed out that the scientists found that emissions from land-use change are only “a minor contributor” to the overall carbon footprint of corn ethanol, accounting for just 7% of total GHG emissions.