The Environmental Protection Agency (EPA) should immediately initiate a process to update its obsolete lifecycle greenhouse gas (GHG) analyses of corn and sugarcane ethanol for the Renewable Fuel Standard (RFS2), according to a letter  sent Friday to EPA Administrator Lisa Jackson from Renewable Fuels Association (RFA) President and CEO Bob Dinneen.
“There have been literally dozens of new studies and modeling improvements since EPA finalized the RFS2 almost three years ago,” Dinneen said. “Overwhelmingly, these new reports and data show that the corn ethanol process is far less carbon intensive than assumed by EPA. Corn ethanol is offering real and significant GHG savings today. Meanwhile, the carbon intensity of crude oil production continues to worsen, as we drill farther and deeper than ever before and get more of our energy from marginal crude sources like tar sands.”
Dinneen also said recent research shows that the lifecycle GHG emissions associated with Brazilian sugarcane ethanol production are worse than originally estimated by EPA for the RFS2. Harvested sugarcane area in Brazil has expanded 55 percent since 2006, with at least 70 percent of that expansion occurring on previous pasture land, research shows. EPA’s analysis assumed virtually no land use change emissions for sugarcane ethanol.
The RFA letter summarizes the results of numerous recent studies and data showing that EPA overestimated ethanol plant energy use, corn farming energy use, and land use change (LUC) emissions. “Indeed, improved modeling and better data show that the corn ethanol process is more efficient and producing less GHG emissions today than EPA assumed would be the case in 2022,” the letter states. On the issue of land use change, Dinneen wrote, “…based on newer data and improved methodologies, the independent estimates of corn ethanol LUC produced since the RFS2 was finalized have generally trended in the range of 8-18 g/MJ. This compares to EPA’s net LUC emissions estimate for corn ethanol of 28.4 g/MJ.”
When recent modeling and data improvements are combined into one analysis, as was done in a recent peer-reviewed paper by researchers at Purdue University and the Department of Energy (DOE), the results are striking. The Purdue and DOE scientists found corn ethanol, on average, reduces GHG emissions today by at least 24 percent compared to gasoline even with speculative LUC emissions included. GHG reductions for ethanol from dry mill plants are even larger.
Dinneen said it is imperative that EPA recognizes this new science and data for several reasons. “EPA has been a leader in the field of biofuels lifecycle assessment, and initiating a process to update the RFS2 analysis ensures that the Agency maintains an active and relevant role in the scientific discussion around biofuel lifecycle GHG accounting,” he wrote. “Second, an effort by EPA to update its analysis will enhance the public’s understanding of corn ethanol’s lifecycle GHG impacts and serve to inform debate on future biofuels policies. In addition, updated analyses of corn and sugarcane ethanol will allow for fairer comparisons of the two fuels moving forward. Finally, updating EPA’s analysis would help ease the Agency’s workload and reduce the backlog of petitions for new pathways.”
Click here  to read the letter in full along with supporting charts and sources.