CORN ETHANOL GHG EMISSIONS UNDER VARIOUS RFS IMPLEMENTATION SCENARIOS

The Clean Air Task Force (CATF) argues that US corn ethanol's lifecycle GHG emissions are significantly higher than EPA estimates. By shifting the analysis period to 2010-2044, CATF finds that corn ethanol emissions are approximately 28% higher than gasoline. The paper further examines scenarios where the shortfall in cellulosic biofuel production is filled by other fuels, finding that allowing sugarcane ethanol imports or additional corn ethanol would substantially increase total CO2 emissions.

• A reanalysis of EPA data indicates that if the 30-year lifecycle GHG emissions for corn ethanol were measured starting from the 2010-2015 ramp-up period rather than 2022, net emissions would be approximately 28% higher than those from gasoline.
• The EPA's 2010 lifecycle analysis is criticized for using 2022 as a starting point, which the CATF claims obscures the impact of indirect land use change (ILUC) and assumes lower production emissions than were present in 2012.
• Between 2010 and 2015, corn ethanol added 745 million tons of CO2 equivalent to the atmosphere, compared to 149 million tons from an energy equivalent amount of gasoline.
• The document identifies a 'cellulosic void' where cellulosic biofuel production is projected to fall short of the Energy Independence and Security Act of 2007 targets; for 2022, the OECD forecasts a maximum of 4.7 billion tons available against a target of 16 billion gallons.
• Under 'Option 2', where the US imports Brazilian sugarcane ethanol to fill the cellulosic void and Brazil imports US corn ethanol in return, CO2 emissions would increase by 34% relative to the RFS2 baseline for the period 2010-2040.
• Under 'Option 3', where conventional biofuels are allowed to directly fill the cellulosic void, CO2 emissions for the period 2010-2040 would more than double, representing a 117% increase over the RFS2 baseline.

APA

Brick, S., & Lewis, J. (2013). CORN ETHANOL GHG EMISSIONS UNDER VARIOUS RFS IMPLEMENTATION SCENARIOS. Clean Air Task Force. https://cdn.catf.us/wp-content/uploads/2019/10/21093500/20130405-CATF-White-Paper-Corn-GHG-Emissions-Under-Various-RFS-Scenarios.pdf

Chicago

Brick, Steve, and Jonathan Lewis. CORN ETHANOL GHG EMISSIONS UNDER VARIOUS RFS IMPLEMENTATION SCENARIOS. Clean Air Task Force, 2013. https://cdn.catf.us/wp-content/uploads/2019/10/21093500/20130405-CATF-White-Paper-Corn-GHG-Emissions-Under-Various-RFS-Scenarios.pdf.

Wikipedia

{{cite report |last1=Brick |first1=Steve |last2=Lewis |first2=Jonathan |title=CORN ETHANOL GHG EMISSIONS UNDER VARIOUS RFS IMPLEMENTATION SCENARIOS |publisher=Clean Air Task Force |date=April 2013 |url=https://cdn.catf.us/wp-content/uploads/2019/10/21093500/20130405-CATF-White-Paper-Corn-GHG-Emissions-Under-Various-RFS-Scenarios.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{brick2013corn, author = {Brick, Steve and Lewis, Jonathan}, title = {{CORN ETHANOL GHG EMISSIONS UNDER VARIOUS RFS IMPLEMENTATION SCENARIOS}}, institution = {Clean Air Task Force}, year = {2013}, month = apr, url = {https://cdn.catf.us/wp-content/uploads/2019/10/21093500/20130405-CATF-White-Paper-Corn-GHG-Emissions-Under-Various-RFS-Scenarios.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }