Did we ever figure out whether corn-based ethanol is good or bad for our beloved planet?

Kicking off a new Doublethink category for this blog…. “Biden will allow summertime sales of higher-ethanol gas as prices remain elevated.” (NYT):

Gasoline that contains ethanol reduces pollution, as indicated by the “Cleaner Air for Iowa” sticker (not to be confused with an “I did that” Joe Biden sticker, which can lead to being arrested).

The text of the article, however, says that gasoline that contains ethanol increases pollution:

Ethanol is made from corn and other crops and has been mixed into some types of gasoline for years as a way to reduce reliance on oil. But the blend’s higher volatility can contribute to smog in warmer weather. For that reason, environmental groups have traditionally objected to lifting the summertime ban…

Oil refiners are required to blend some ethanol into gasoline under a pair of laws, passed in 2005 and 2007, intended to lower the use of oil and the creation of greenhouse gases by mandating increased levels of ethanol in the nation’s fuel mix every year. However, since passage of the 2007 law, the mandate has been met with criticism that it has contributed to increased fuel prices and has done little to lower greenhouse gas pollution.

Perhaps the contradiction is only an apparent one in that the ethanol blend will reduce pollution in colder weather.

This reminded me to wonder if anyone has ever figured out definitively whether this 17-year-old policy helps or harms Planet Earth. Consider “U.S. corn-based ethanol worse for the climate than gasoline, study finds” (Reuters, February 14, 2022):

Corn-based ethanol, which for years has been mixed in huge quantities into gasoline sold at U.S. pumps, is likely a much bigger contributor to global warming than straight gasoline, according to a study published Monday.

The study, published in the Proceedings of the National Academy of Sciences, contradicts previous research commissioned by the U.S. Department of Agriculture (USDA) showing ethanol and other biofuels to be relatively green.

The research, which was funded in part by the National Wildlife Federation and U.S. Department of Energy, found that ethanol is likely at least 24% more carbon-intensive than gasoline due to emissions resulting from land use changes to grow corn, along with processing and combustion.

Under the U.S. Renewable Fuel Standard (RFS), a law enacted in 2005, the nation’s oil refiners are required to mix some 15 billion gallons of corn-based ethanol into the nation’s gasoline annually. The policy was intended to reduce emissions, support farmers, and cut U.S. dependence on energy imports.

As a result of the mandate, corn cultivation grew 8.7% and expanded into 6.9 million additional acres of land between 2008 and 2016, the study found. That led to widespread changes in land use, including the tilling of cropland that would otherwise have been retired or enrolled in conservation programs and the planting of existing cropland with more corn, the study found.

Tilling fields releases carbon stored in soil, while other farming activities, like applying nitrogen fertilizers, also produce emissions.

A 2019 study from the USDA, which has been broadly cited by the biofuel industry, found that ethanol’s carbon intensity was 39% lower than gasoline, in part because of carbon sequestration associated with planting new cropland.

We have Scientific Certainty (TM) on all subjects related to COVID, e.g., the effectiveness of ordering schoolchildren to wear masks, the ability of vaccines to end the global pandemic (just one more shot for all of us and SARS-CoV-2 will be gone!), and the need to require incoming travelers from zero-COVID China to produce a negative test while the undocumented may stream over the southern border and stay indefinitely with no testing or vaccination prerequisite. The question of whether growing more corn to burn in our pavement-melting SUVs increases or decreases CO2 emissions should be a comparatively simple one and yet Science cannot agree with him/her/zir/theirself.

Readers: What do we think? Do we go with the obvious “corn-based ethanol is bad”? Or are we convinced by the USDA??

Separately, for California readers, a couple of photos from Sunday, April 10 at Florida’s Turnpike Exit 152:

Related:

  • Factory farms may be killing coral reefs, not a warming planet (fertilizer dumped on corn fields eventually finds its way into the ocean)
  • Book that explores the biggest issue of our age: About 40 percent of the fertilizer applied in the last sixty years wasn’t assimilated by plants; instead, it washed away into rivers or seeped into the air in the form of nitrous oxide. Fertilizer flushed into rivers, lakes, and oceans is still fertilizer: it boosts the growth of algae, weeds, and other aquatic organisms. When these die, they rain to the ocean floor, where they are consumed by microbes. So rapidly do the microbes grow on the increased food supply that their respiration drains the oxygen from the lower depths, killing off most life. Where agricultural runoff flows, dead zones flourish. Nitrogen from Middle Western farms flows down the Mississippi to the Gulf of Mexico every summer, creating an oxygen desert that in 2016 covered almost 7,000 square miles.
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