WASHINGTON – U.S. Agriculture Secretary Tom Vilsack announced a report studying the lifecycle greenhouse gas (GHG) balance of corn ethanol. The report, A Life-Cycle Analysis of the Greenhouse Gas Emissions of Corn-Based Ethanol, finds that GHG emissions associated with U.S. corn-based ethanol are about 43% lower than gasoline when measured on an energy equivalent basis.

"This report provides evidence that corn ethanol can be a GHG-friendly alternative to fossil fuels, while boosting farm economies," Vilsack said.

The new report found greater lifecycle GHG benefits from corn ethanol than earlier studies, driven by improvements in ethanol production. Farmers are producing corn more efficiently and using conservation practices that reduce GHG emissions, including reduced tillage, cover crops and improved nitrogen management. Corn yields are also improving, increasing by more than 10% between 2005 and 2015, and during that same time U.S. ethanol production increased from 3.9 to 14.8 billion gallons per year.

By 2022, the USDA report says that the GHG profile of corn-based ethanol is expected to be almost 50% lower than gasoline, primarily due to improvements in corn yields, process fuel switching and transportation efficiency.

The report also examined the benefits of improving the efficiency of ethanol refinery plants and adoption of additional conservation practices on corn-producing farms. In a scenario where these improvements and practices are universally adopted, the GHG benefits of corn ethanol are even more pronounced over gasoline, about a 76% reduction, according to the report.