Ethanol Is Worse for the Climate Than Gasoline, Study Finds

It's just another subsidy we all pay to keep cars fat and happy.

Corn grown for Ethanol

 Scott Olson / Getty Images

Treehugger has been spotlighting the famous Andy Singer cartoon below since he drew it in 2007 while complaining about the Energy Independence and Security Act, signed by former President George Bush, and its renewable fuel standard (RFS). Environmentalists have long complained there was no real benefit, but farmers love it and every politician loves farmers.

Andy Singer Cartoon about Ethanol

Andy Singer

New research, published in the Proceedings of the National Academy of Science, led by the University of Wisconsin–Madison confirms Singer's cartoon is dead on. The researchers found RFS increased corn prices by 30%, expanded corn cultivation by 8.7%, increased fertilizer use by 3 to 8%, degraded the water supply with chemical runoff, and "caused enough domestic land use change emissions such that the carbon intensity of corn ethanol produced under the RFS is no less than gasoline and likely at least 24% higher."

“It basically reaffirms what many suspected, that corn ethanol is not a climate-friendly fuel and we need to accelerate the shift toward better renewable fuels, as well as make improvements in efficiency and electrification,” said scientist Tyler Lark, the lead author, in a press release.

As originally conceived, the RFS was supposed to encourage the development of cellulosic biofuels that didn't compete for the land where food is grown, but they have not proven to be economically viable, so corn grain ethanol fills 87% of the RFS mandate. Treehugger has long complained about feeding corn to cars instead of people, and in a time when food prices are rising fast, it seems particularly silly.

One of the major sources of the emissions due to ethanol production comes from land-use changes (LUC), which lead to increased environmental impacts. The study notes: "The previously underestimated emissions from US land conversion attributable to the policy are enough to fully negate or even reverse any GHG advantages of the fuel relative to gasoline. Our findings thereby underscore the importance of including such LUCs and environmental effects when projecting and evaluating the performance of renewable fuels and associated policies."

Or, as Lark explains:

“The EPA’s original estimates suggested that U.S. land use change would sequester carbon and help improve the carbon footprint of ethanol. But in retrospect, we now know it did just the opposite,” Lark says. “Rather than reduce the carbon intensity of ethanol to 20% lower than gasoline, it looks like it actually increases it to that much higher than gasoline.”

This has proven to be the most controversial finding and has been challenged by the Renewable Fuels Association, the group "working to drive expanded demand for American-made renewable fuels." Its president bluntly states that "the authors of this new paper precariously string together a series of worst-case assumptions, cherry-picked data, and disparate results from previously debunked studies to create a completely fictional and erroneous account of the environmental impacts of the Renewable Fuel Standard." Their backup documentation (PDF) claims increased corn supply comes from yield increases and crop switching, not from acreage expansion.

The Renewable Fuels Association is hardly an unbiased source, given that, according to the Environmental Working Group, farm subsidies ballooned under former President Donald Trump to $20 billion to compensate for losses due to Chinese tariffs on agricultural imports due to trade wars. There's real money in this, and Americans are paying for this in two ways, through increased prices for food and out of their taxes for subsidies.

Meanwhile, Lark suggests there should be more research into alternatives that are not grown on farmland.

“We use a lot of land for corn and ethanol right now,” Lark said. “You could envision replacing the existing 15 billion gallons of corn ethanol with next-generation biofuels as that production comes online. That would give an opportunity to restore millions of acres of cornfields into perennial native grasslands and other landscapes that could potentially be utilized for bioenergy, still be economically productive, and also help reduce nitrate leaching, erosion and runoff.”

One might suggest other alternatives; increasing fuel economy standards could eat up that 15 billion gallons pretty quickly. It's all just another subsidy to the automobile, the price everybody pays in air and water quality, taxes, and food prices to keep cars fat and happy.

Other researchers suggest that planting an acre of solar panels could drive an electric car 70 times the distance than an acre of corn could, and earn the farmer three times as much income. Someone should tell the Renewable Fuels Association the best renewable fuel comes from that big fusion reactor in the sky.

View Article Sources
  1. Lark, Tyler J., et al. "Environmental Outcomes of the US Renewable Fuel Standard." Proceedings of the National Academy of Sciences, vol. 119, no. 9, 2022, p. e2101084119., doi:10.1073/pnas.2101084119

  2. "Cellulosic Biofuel." ScienceDirect.

  3. Schechinger, Anne. "Under Trump, Farm Subsidies Soared and the Rich Got Richer." Environmental Working Group, 2021.

  4. Nussey, Bill. "Making Ethanol From Corn is the Least Efficient Use of Farmland." Freeing Energy, 2021.