USDA: Study shows significant GHG benefits of corn ethanol

By Erin Voegele | April 02, 2019

The USDA released a new study April 2 that finds greenhouse gas (GHG) emissions from corn ethanol are about 39 percent lower than gasoline. When ethanol is produced at natural gas-powered refineries, GHG emissions are even lower, approximately 43 percent below gasoline.

The study was led by Jan Lewandrowski of the USDA’s Office of the Chief Economist and published in the journal Biofuels. According to the USDA, the study supports findings of other research that ethanol has a significantly better GHG profile that previously estimated.

The study attributes much of these additional benefits to revised estimates of the impacts of land-use change as a result of demand for ethanol. While previous estimates anticipated farmers bringing additional land into production as a result of increased corn prices, the USDA said recent analysis has found only modest increases in crop acreage.

The USDA also said additional improvements at ethanol plants, combined with on-farm conservation practices that reduce GHG emissions, such as reduced tillage and cover crops, have further decreased emissions associated with corn ethanol. The study projects that additional improvements at ethanol plants and on farms will allow a reduction of more than 70 percent in lifecycle emissions to be possible by 2022.

“These new findings provide further evidence that biofuels from America's heartland reduce greenhouse gases even more than we thought, and that our farmers and ethanol plants continue to become more efficient and effective,” said Agriculture Secretary Sonny Perdue. “President Trump has made it abundantly clear he is unleashing the full potential of American energy production as we retake our rightful place as the world’s leader. Expanding the sale of E15 year-round will provide consumers with more choices when they fill up at the pump, including environmentally friendly fuel with decreased emissions. I appreciate EPA Administrator Andrew Wheeler moving expeditiously to finalize the E15 rule before the start of summer driving season.”

Growth Energy has spoken out to welcome the report’s findings. “This new USDA study further supports that ethanol is a win-win for all Americans,” said Growth Energy CEO Emily Skor. “Higher ethanol blends provide not only tremendous health and environmental benefits, but economic benefits as well for rural America and our farmers. Our industry remains committed to cleaner fuel options for all drivers, and ethanol’s role in reducing GHGs is among the reasons why. We look forward to drivers experiencing these benefits and more when they soon have access to E15 year-round.”

Additional information, including a link to the full study, titled “The greenhouse gas benefits of corn ethanol—assessing recent evidence,” is available on the USDA website