Corn-based Ethanol is 24% More Carbon Intensive Than Gasoline: Study

According to a recent study published in the Proceedings of the National Academy of Sciences, corn-based ethanol, which has been blended in massive amounts into gasoline sold at U.S. pumps for years, is likely a significantly greater contribution to global warming than plain gasoline.

The study finds that using corn-based ethanol to fuel our automobiles may have done more damage than good.

The research, first reported by Reuters, says the carbon intensity of corn-based ethanol is “likely at least 24 percent greater” than normal gasoline, which is not a promising statistic.

This research looks at how land and water resources were used in the United States over the eight years of the government’s Renewable Fuel Standard program, which ran from 2008 to 2016. “The RFS is a national program that mandates a particular amount of renewable fuel to substitute or reduce the quantity of petro – based transportation fuel, heating oil, or jet fuel,” according to the US Environmental Protection Agency.

But what is ethanol, which appears to be made from pure maize, so much worse than gasoline? Petroleum-based fuels are extremely filthy when drilling, refining, and transporting them are all taken into account. This research takes a comprehensive approach, looking at a variety of factors: “Here we combine econometric studies, land use observations, and biophysical models to estimate the realized impacts of the RFS in aggregate and down to the size of individual agricultural fields across the United States.” In other words, researchers looked at much more than simply what came out of a car’s exhaust.

According to this study, the RFS increased corn demand, which raised maize planting by 8.7 percent and fertilizer usage by up to 8 percent. This reduced ecosystem carbon reserves, resulting in increased nitrate leaching, phosphorus runoff, and soil erosion, but that’s not all. According to researchers, the RFS boosted maize prices by a stunning 30% and other crop expenses by a shocking 20%.

These findings contradict a 2019 research by the United States Department of Agriculture, which claims corn-based ethanol is considerably cleaner than petroleum, emitting 39% less greenhouse gas than gasoline. However, it appears that the research did not take land usage into account in its estimations.

The RFS has mandated an increasing quantity of renewable energy to be utilized each year. 36 billion gallons will need to be generated by 2022. This appears to be a positive thing for the environment, but it might be quite the reverse. According to the research, “…our findings demonstrate that current corn ethanol production is unlikely to contribute to climate change mitigation.” If fuels like cellulosic ethanol or biomass-based diesel can be ramped up, the picture may change, but for the time being, such possibilities appear restricted.