EPA is vigorously questioning results of a U.S. Department of Energy (DOE)-funded study that concludes ethanol produced from crop residues such as corn stover can have higher lifecycle greenhouse gas (GHG) emissions than conventional gasoline, arguing that the findings are based on an "extremely unlikely scenario" of unsubstantiated agricultural practices. RFA is also highly critical of the new study, claiming its "methodology is fundamentally flawed and its conclusions are highly suspect." RFA made available a useful fact sheet that is available online.

The DOE-funded study was published on April 20, 2014, in Nature Climate Change. The study claims to demonstrate that ethanol produced from corn stover and other crop residues does not meet EPA's criteria for achieving a 60 percent GHG emission reduction compared to gasoline in order for the fuels to qualify under the RFS. The study could raise questions over EPA's ability to raise the cellulosic target in the final version of the 2014 RFS, especially if the fuel's GHGs disqualify them under the program.

EPA is also refuting the study as hypothetical, and lacking a firm basis in current agriculture practices. An EPA spokeswoman reportedly stated the "paper is based on a hypothetical assumption that 100 percent of corn stover in a field is harvested; an extremely unlikely scenario that is inconsistent with recommended agricultural practices." More information is available online.