The American Coalition for Ethanol (ACE) responded to the Environmental Protection Agency (EPA) Science Advisory Board (SAB) workgroup draft commentary letter to Administrator Regan regarding the Renewable Fuel Standard (RFS) “Set” Rule, particularly countering the biased allegations made by the workgroup concerning the greenhouse gas emissions (GHG) impacts of corn starch ethanol. ACE CEO Brian Jennings’ responses are aimed at setting the record straight leading up to the SAB’s September 21-22 public meeting.

Although the SAB does not have statutory authority to promulgate EPA regulations, Jennings refutes the misleading claims made by the RFS workgroup centering on the degree to which corn starch ethanol reduces lifecycle GHG emissions compared to gasoline.

The SAB workgroup letter makes the outrageous claim that corn starch ethanol may not meet the necessary scientific requirement of having no more than 80 percent of the lifecycle GHG emissions of gasoline. In fact, corn starch ethanol greatly exceeds the necessary scientific requirements as demonstrated by the best available lifecycle science (via the GREET model), which shows corn starch ethanol is at least 50 percent cleaner than the GHG emissions of gasoline on average.

“There is no fact-based debate regarding the lifecycle GHG emissions of corn starch ethanol compared to gasoline,” Jennings stated in ACE’s response. “To the degree debate exists at all, it is not vigorous, unless one takes into consideration the vigor of misinformation campaigns orchestrated by various groups who are self-interested in their opposition to ethanol.

ACE again called on EPA to replace its approach for assessing the GHG impacts of corn starch ethanol with the GREET model in the comments. The SAB letter provides no mention of the GREET model but makes multiple references to discredited studies by Tyler Lark et al., with land use change (LUC) at the center of Lark’s attacks on corn ethanol. “While the Lark paper received outsized attention from the RFS workgroup letter, his biased methodology led to a LUC “result” which is far outside GREET CCLUB [Carbon Calculator for Land Use and Land Management Change from Biofuels production] results and other comprehensive and authoritative research done on this topic,” Jennings’ comments state.

The workgroup letter closes by referring to N20 emissions from corn farming. Jennings responds with additional information on the critically important topics of how farming practices can play a meaningful role in reducing lifecycle GHG emissions for corn starch ethanol, as well as reduced tillage practices to increase soil carbon sequestration.

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