Biofuels Groups Contend EPA’s Corn Ethanol Lifecycle Emissions Woefully Out of Date

In March, the Urban Air Initiative, the Energy Future Coalition and the Governors’ Biofuels Coalition provided data to the EPA on the lifecycle emissions of ethanol.  The groups state that the agency’s own assessment of ethanol lifecycle emissions – the sum total of emissions from farming, refining, transportation – are woefully out of date. The agency last conducted a comprehensive assessment of ethanol lifecycle emissions in 2010.

Last fall, the EPA’s Office of Inspector General (OIG) announced that it would research the greenhouse gas (GHG) impacts of the Renewable Fuel Standard (RFS).  The role of the RFS in reducing U.S. GHGs fell under intense scrutiny when EPA proposed reducing the statutory volumes of renewable fuels in 2013.

According to the groups, “new data and improved methodologies have established that the lifecycle GHG emissions attributable to corn ethanol are much lower than suggested … [in] EPA’s latest estimate … [therefore], EPA should revisit and update its outdated lifecycle emissions estimate.”

Under the RFS, renewable fuels are categorized by their greenhouse gas reduction potential, as compared to traditional petroleum-based fuels. When the RFS was signed into law, Congress mandated lifecycle GHG reduction targets for renewable fuels and instructed EPA to oversee this process. Corn-based ethanol must have a GHG reduction of 20 percent relative to gasoline and cellulosic ethanol must reduce emissions by 60 percent. According to more recent modelling studies conducted by DOE’s Argonne National Lab, the lifecycle emissions of corn ethanol is on average, 24 percent less carbon intensive than gasoline. Cellulosic ethanol may be up to 96 percent lower than gasoline, according to Argonne’s research.

The groups contend that the reports which OIG will use to assess EPA’s compliance with lifecycle analysis, including a 2011 National Academy of Sciences report, are deeply flawed and out of date. The groups also state that an evolving understanding of the environmental effects of the RFS warrant a second look at post-2010 data.  They include:  

• Lower levels of land-use change due to the Renewable Fuel Standard than initially expected;
• Improved agricultural practices that reduce fossil inputs (fertilizer, fuels) and increase soil carbon storage of soils;
• Efficiency improvements at biofuels refineries, including use of waste heat at many facilities, reduction of coal and natural gas use, and the development of new co-products. 

According to the groups, the agency’s consideration of ethanol’s benefits should go beyond GHGs, to also include impacts of ethanol blending to tailpipe emissions, which reduces particulate matter, nitrous oxide (a smog precursor), and other air toxics in the urban environment.  The EPA has until August 11 to respond to the request.  

For more information see:

Evidence Shows EPA Should Boost Lifecycle GHG Benefits of Ethanol, 25x’25

EPA’s Office of Inspector General to Investigate GHG Impacts of Renewable Fuel Standard, EESI