New reports reveal ethanol’s potential to reduce GHG emissions
The academic studies additionally call into question the reliability of recent analysis of land use change, which have been based on apparently flawed satellite imagery-based methodologies.
According to the RFA, this new research will enable policymakers and regulators to focus on the advances being made by corn farmers and ethanol producers in sustainability and efficiency.
“As the Environmental Protection Agency (EPA) considers the GHG impacts of expanded ethanol consumption under the Renewable Fuel Standard, we urge them to strongly consider the latest science and data regarding ethanol’s tremendous carbon benefits,” said RFA President and CEO Geoff Cooper.
“At the same time, we implore EPA to exercise great caution and prudence when considering the results of flawed land use change studies reliant on data from satellites that, frankly, can’t tell the difference between a pasture and a parking lot. The land use research relied upon by EPA for its Second Triennial Report to Congress was so flawed and erroneous that it simply cannot be used for regulatory decision-making, and we urge EPA not to make the same mistake as it considers future regulatory actions on the RFS.”
One of the studies, which was carried out by the Laboratory for Applied Spatial Analysis at Southern Illinois University Edwardsville (SIUE-LASA), highlights the flaws in research into land use change based on satellite imagery, which was referenced in the EPA’s 2018 Second Triennial Report.
The review of the data sets and methodologies used in the previous research were revealed by SIUE-LASA to contain a number of considerable errors, with areas of water, forest and pasture being misclassified.
The second study, which was partially funded by the US Department of Energy (DOE) and the US Department of Agriculture (USDA), found that corn residue retained on fields results in the sequestration of approximately 0.41 metric tons of carbon per hectare per year in the soil.
This finding suggests that the carbon intensity of corn-based ethanol is significantly below current estimates by the EPA, the California Air Resources Board, and others. It also implied that leaving more residue on fields can have a larger carbon benefit than removal and conversion into ethanol.
Accurately accounting for the soil carbon sequestration benefits of corn production would reduce the existing lifecycle ‘carbon intensity score’ of corn ethanol by 20-25%, meaning most dry mill corn ethanol produced would result in 50-65% GHG savings compared to gasoline.
This research was carried out by a team of environmental and soil scientists from the DOE’s Argonne National Laboratory, the USDA’s Agricultural Research Service, South Dakota State University and the South Dakota School of Mines and Technology.