New research from Environmental Health & Engineering, Inc. (EH&E), a US-based research and advisory company, shows that greenhouse gas (GHG) emissions for corn-derived ethanol, are 46 percent lower than gasoline. Conventional wisdom based on a prior analysis done by the US Environmental Protection Agency (EPA) had pegged the difference to only 20 percent.
EH&E’s topical review of the latest science shows that this renewable biofuel is less carbon-intensive and more climate-favorable than previously thought. The paper “Carbon intensity of corn ethanol in the United States: state of the science“, is currently an Accepted Manuscript for Environmental Research Letters.
This research provides an up-to-date accounting of corn starch ethanol’s GHG profile in comparison to that of gasoline refined from crude oil. The results of this research are timely for the scientific, public health, legislative, and business communities seeking to establish a net-zero carbon economy while addressing related technological, political, and economic challenges said David MacIntosh, Chief Science Officer at EH&E.
The research delivers a transparent, state-of-the-science assessment on life cycle analyses of corn starch ethanol in the U.S. EH&E researchers reached their conclusions after critically reviewing earlier life cycle analysis modeling and data, and consulting with more than two dozen experts from government, academia, and nonprofits.
Their findings uncovered significant reductions in carbon intensity made possible by advances in farming technology, soil conservation practices, and the production of animal feed as a by-product of making ethanol.
Much lower land-use change than previously thought
EH&E’s assessment also shows that carbon emissions from converting prior land use to corn farming make up only 3.9 percent of the biofuel’s total GHG emissions–a much smaller amount than generally recognized.
This finding stems directly from the latest models and data that consider both the economic value and productivity of land to estimate the release of carbon when land is put into corn production.
The research’s findings suggest that the substitution of conventional gasoline with corn ethanol could deliver a net carbon sink over a much shorter period than previously estimated.
Corn-derived ethanol currently accounts for about 10 percent of liquid fuel sold at gasoline stations in the United States and has the potential to account for a greater share of liquid fuel for transportation.
The findings provide much-needed data for decisions and policies on the future role of biofuels to address climate change as well as opportunities for continued reduction of carbon emissions across the life cycle of corn ethanol.
