The rise of global temperatures and cataclysmic natural disasters and weather events have hastened and intensified policy discussions around carbon’s role in climate change. With renewable fuels like ethanol, we don’t have to wait and hope for major technological or economic breakthroughs; the fuel is available now at a low cost to drive the decarbonization of liquid fuels.
Grain-based ethanol cuts greenhouse gas emissions significantly—by 35 to 50% compared to gasoline. Emerging technologies promise to boost that reduction to near 70% in the next few years, according to USDA. And ethanol made from corn kernel fiber and other cellulosic feedstocks is already delivering reductions of 80% or more.
How does this work? Plants that are made into renewable fuels absorb carbon dioxide from the atmosphere as they grow, and that same amount of carbon dioxide is re-released when the fuel is produced and combusted in an engine. In this way, ethanol and other renewables simply recycle atmospheric carbon. Even when the energy use and emissions related to the full production process are accounted for, ethanol delivers significant GHG savings compared to the fossil fuels it replaces.
Ethanol’s Significant GHG Emissions Reductions
Research from Environmental Health & Engineering Inc. (Jan. 2021) shows that greenhouse gas emissions for ethanol are 32 to 62% lower than gasoline, with a central best estimate of 46%.
The use of ethanol in gasoline in 2020 reduced CO2-equivalent greenhouse gas emissions from the transportation sector by 47.3 million metric tons, according to RFA analysis using the U.S. Department of Energy’s GREET model.
That’s equivalent to removing 10.1 million cars from the road for an entire year, or eliminating the annual emissions from 12 coal-fired power plants!