Biofuels from switch grass and post-harvest corn waste could reduce carbon emissions related to climate change more effectively than conventional corn ethanol, experts from the Environmental Working Group (EWG) and University of California at Davis concluded in a new report.
EWG measured the carbon emitted over the lifecycle of ethanol made from switchgrass and from corn stover, the stalks and leaves left on fields after harvesting. It found that the lifecycle carbon intensity of corn stover ethanol is 96% lower than gasoline and that of switchgrass ethanol is 47% lower.
By contrast, the Nov. 3 report continued, a 2010 US Environmental Protection Agency study found that corn ethanol’s lifecycle carbon emissions are greater than gasoline’s. “Yet current federal policies strongly favor the production of conventional biofuels such as corn ethanol at the expense of lower-carbon alternatives,” it said.
It urged Congress to reform the RFS by eliminating the mandate to add corn ethanol to gasoline, and further reform the program, which the 2005 Energy Policy Act established and 2007 Energy Independence and Security Act expanded, to accelerate biofuels development from lower carbon feedstocks.
Federal lawmakers also should adopt new protections to ensure that fuels from grasses and crop waste also meet soil and water quality goals, the report added. It said that if Congress fails to act, EPA should employ the RFS’s “reset” provisions to gradually reduce the corn ethanol mandate and encourage development of lower-carbon second-generation fuels.
“When the Renewable Fuel Standard was established, corn ethanol was touted as being cleaner than gasoline, but 10 years later we know it’s just the opposite,” said EWG Research Analyst Emily Cassidy, who wrote the report. “It’s time to break up the corn ethanol monopoly to make room for next-generation biofuels that could reduce carbon emissions.”
A corn ethanol lobbyist responded that a US Department of Energy study found that corn ethanol represents a 34% reduction from carbon emissions compared to gasoline. Third Way, a centrist think tank, has said that corn ethanol and other first-generation biofuels are essential to make cellulosic and other advanced biofuels commercially viable, the lobbyist added.
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