A new analysis from a renowned carbon accounting firm finds that the greenhouse gas emission reductions achieved under the Renewable Fuel Standard far exceed the reductions originally projected by EPA. Between 2008 and 2020, the use of biofuels under the RFS has resulted in cumulative savings of 980 million metric tons of carbon dioxide-equivalent greenhouse gas emissions.
The research, which updates the results from a previously published study, was conducted for the Renewable Fuels Association by Stefan Unnasch and Debasish Parida of Life Cycle Associates.
The greater-than-expected GHG savings are attributable to several factors: corn ethanol provided larger GHG reductions than anticipated by EPA; the actual carbon intensity of gasoline and diesel was worse than estimated by EPA; and use of biodiesel and renewable diesel exceeded EPA’s original expectations.
“The Renewable Fuel Standard has been the single most effective and efficient policy we’ve ever had for decarbonizing our nation’s transportation fuels,” said RFA President and CEO Geoff Cooper. “This research clearly demonstrates that the RFS has already put us firmly on the path toward net-zero GHG emissions by mid-century, and the program will continue to serve as the bedrock for future efforts to combat climate change. The RFS has overachieved its original expectations, and renewable fuel producers and farmers across the country should be extremely proud of their important role in securing 1 billion metric tons of carbon reduction.”
According to the report, the carbon intensity of corn-based ethanol used toward the RFS is now 45% below the carbon intensity of gasoline, having dropped 20% between 2008 and 2020. The authors attribute ethanol’s shrinking carbon footprint primarily to improvements in the corn ethanol production process, growth in the use of low-carbon biogas as the process fuel, and the elimination of coal as a thermal energy source for dry mill ethanol plants.
Cooper noted that the Life Cycle Associates study is consistent with recently released research from Environmental Health & Engineering Inc., which showed that GHG emissions for ethanol are 32% to 62% lower than gasoline, with a central best estimate of 46%. In addition, the assessment showed that carbon emissions from converting prior land uses to corn farming make up only 7% of the biofuel’s total GHG emissions—a much smaller amount than generally recognized.