No, Corn Ethanol Isn’t Agriculture’s Walter White. But Our Ethanol Rules Might End Up Breaking Bad


(Somebody call the headline police. That’s just embarrassing.)

This Think Progress article wondering if corn was breaking the law by being transformed into ethanol is poorly written, poorly sourced and pretty much just wrong, but it does inadvertently highlight an odd set of contradictory incentives baked into the renewable fuel standard.

Corn ethanol may be breaking the law, according to a study from last month, “Cropland Expansion Outpaces Agricultural and Biofuel Policies in the United States.”

It appears that corn was caught yellow-handed by University of Wisconsin-Madison researchers in a plot with other crops like soy to replace “millions of acres of grasslands.” But scientists named corn the ring-leader: “Corn was the most common crop planted directly on new land.”

I know you’re wondering, “since when is it illegal to replace carbon-storing grassland with the Walter White of Biofuels?” Answer: Since the federal Renewable Fuel Standard (RFS), “which requires blending of gasoline with biofuels that are supposed to be grown only on pre-existing cropland, in order to minimize land-use change and its associated greenhouse gas emissions,” as the UWM news release explains.

Now if only anybody were actually enforcing the law, the anti-hero of biofuels would be perp-walked to prison for destroying the very environment it was supposed to help protect.

The problem is that there hasn’t been the expansion in crop land under cultivation that would trigger enforcement of the restriction. The way the law is written, if the amount of US cropland under cultivation goes above what it was in 2007, then producer are required to show that the corn they are using came from acreage that was already under cultivation in 2007. We aren’t there yet. (And the paper that the Think Progress paper is reporting on has some issues of it’s own.)

What struck me was how the incentives written into the law cut against each other. The Renewable Fuel Standard program creates demand for corn for ethanol by mandating it’s use. But it also constrains the supply by limiting the acres that the corn can be grown on. This kind of dissonance can lead to perverse outcomes. Pushing up demand while limiting supply seems like a recipe for fraud. What else would you expect if you raise the price paid for corn and then tell some farmers that they aren’t allowed to grow corn. Thankfully, that scenario is only theoretical. The trend line for the amount of land under cultivation is downward sloping. Between the remarkable increases in agricultural productivity (high yields, low losses) and the decrease in meat consumption, agriculture is using less and less land to produce more food for a growing population (growing in more ways than one). That’s a very real environmental upside of technologically advanced agriculture.

However, setting a limitation on cultivating new land for ethanol corn calls the question of the sustainability of corn ethanol. One might ask how sustainable it could be if it doesn’t pencil out if you need to plow up new land to produce it. But that says more about how big an impact plowing up new land is than it says about the relative merits of corn ethanol. Plowing up land releases a lot of sequestered carbon and disturbs the existing eco-system more than any other subsequent choice that a farmer makes after that.

The premise of the legislators was that it IF it is produced on existing farmland, THEN it is a net gain for the environment. But IF it requires plowing under new land, THEN the carbon emissions from plowing up that land will swamp the gains from switching to ethanol from petrol. That may be fine. I haven’t done the deep dive into understanding how all the numbers on ethanol crunch out, but while it shows that corn ethanol is no slam dunk for the environment, hence the conditional logic, it’s OK to recognize that somethings are good under one set of conditions and not good under another set of conditions. I’ve long thought that it’s a shame that more people didn’t learn to program in BASIC during the 80’s. IF that had been the case, THEN more people would have internalized the usefulness of conditional logic. Now that’s a crime.

The FAFDL discussion that inspired and informed this post can be found here.

I’m overdue for a deep dive into the pros and cons of corn ethanol, but I think this lecture by David Tilman of the University of Minnesota is the best point of departure that I’ve come across thus far.


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1 Comment

  1. I think in order to get a full perspective on corn ethanol, it’s important to take a peek at the story of sugar ethanol in Brazil. The wiki page alone took me a few days to read and digest, it’s incredibly rich and detailed. I highly recommend checking it out. U.S. trade policy with Brazil that has changed over the years, and there’s been recent political changes in Brazil due to the discovery of oil in their own country that have really flipped things around.

    While not applicable to all areas in the U.S., sugar ethanol could be viable (possibly even more appropriate) in some of our southern states, and certainly in other areas of the world, -being watchful for deforestation or conversion issues.

    I don’t know how I really feel about ethanol mandates here in the U.S. – I think a carbon tax would let ethanols compete if they truly deliver a favorable energy/carbon ratio. The video you linked makes a strong case for food being a huge 3rd variable as well.

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