Lower renewable volume obligations under the Renewable Fuel Standard could mean putting the equivalent of one million more passenger cars on the road in the U.S., a University of Illinois at Chicago analysis finds.
The analysis, prepared by the UIC Energy Resources Center, is based on peer-reviewed research and the Greenhouse gases, Regulated Emissions, and Energy use in Transportation model developed by Argonne National Laboratory.
The model examines the full life cycle emissions impacts of energy sources.
As part of the analysis, carbon emissions related to the planting, growing, harvesting, transportation and production of corn into ethanol were compared to that of oil recovery and production.
The findings come just a few weeks after the U.S. EPA wrapped up a public comment period on the revised RVOs, which determine the amount of ethanol blended in gasoline.
If the RFS RVOs are adopted as proposed, a total of 17.5 billion gallons of ethanol would be blended with gasoline by 2016, 3.75 billion fewer gallons than originally mandated by Congress in the 2005 law that authorized the RFS.
"Our work has demonstrated that, over the last 10 years, steady reductions in greenhouse gas emissions have materialized as biofuels became a more efficient, high quality product," said Dr. Steffen Mueller, principal economist at ERC.
Under the EPA's proposed rules, conventional starch ethanol would likely be reduced to 13.4 billion gallons from 15 billion gallons in 2015. In this scenario, the analysis found that 4,520,000 tonnes of additional CO2 emissions would be incurred in 2015.
The single year of carbon emissions is the equivalent to the annual GHG emissions of 951,600 passenger vehicles, according to the EPA's equivalency calculator.
Corn and ethanol groups have been pushing for reinstatement of the RFS RVOs to statutory levels, though EPA said its proposed levels were "ambitious."
At the time, the agency said lower levels were due to constraints in the fuel market to accommodate increasing volumes of ethanol, "along with limits on the availability of non-ethanol renewable fuels."
"The volume targets specified by Congress in the Clean Air Act for 2014, 2015 and 2016 cannot be achieved," EPA's May announcement said.
The National Corn Growers Association helped coordinate a rally earlier this year to support the RFS and continue to push for higher production and blending levels.
Ken Hartman, president of NCGA-affiliated Illinois Corn Growers Association, said it was disappointing that the "same federal agency charged to protect human health and the environment is proposing a rule change that would directly lead to greater greenhouse gas emissions."
EPA also took criticism for the 18 months it took to propose the new levels, a departure from required timelines.
Hartman said after those 18 months, "EPA has chosen not only to shirk its legal obligation as set forth by Congress, but to lose sight of its own mission."
EPA is expected to conclude the rulemaking process and issue a final rule in November.
News source: UIC