06/12/2009 05:12 am ET | Updated May 25, 2011

EPA's New Biofuel Standard: No Joy in Cornville

In its newly proposed rules for biofuels, the U.S. Environmental Protection Agency concludes ethanol is a loser when it comes to reducing greenhouse gas emissions. It's a finding that upset one Congressman so much that he won't "trust anybody anymore."

Corn Ethanol and Washington: The Backstory

The relationship between corn ethanol and the U.S. government has been long and checkered. For nearly three decades the government has subsidized [pdf] ethanol production (and by extension corn growers) by incentivizing its production, even though a gallon of ethanol is typically more expensive than a gallon of regular fossil fuel-based gasoline. (The government has also effectively blocked the import of potentially cheaper ethanol like Brazil's sugar-based variety through high tariffs.)

The arguments in favor of ethanol have been two-fold -- it's supposedly a winning formula for:

  1. national security - using ethanol displaces conventional gasoline and therefore lowers our dependence on foreign oil; and
  2. the planet - because the carbon in ethanol comes from plants that removed it from the atmosphere during photosynthesis, burning ethanol does not add more carbon dioxide (CO2), the main greenhouse gas pollutant, to the atmosphere.

The scientific community has never been entirely sold on these virtues. And many have suspected that the federal largess for corn ethanol has had more to do with putting extra dollars into the hands of farmers. The corn lobby is rather, shall we say, influential. And don't forget that presidential campaigns always start in Iowa -- a corn state if there ever was one. Can you imagine trying to win the Iowa caucuses on a campaign position against subsidies for corn ethanol?

Those Pesky Scientists -- Giving an Earful About the Downsides of Corn

Scientifically speaking, the problem with corn ethanol is that growing corn, transporting it to a factory, and converting it to ethanol all require energy, the vast majority of which comes from fossil fuels that lead to greenhouse gas emissions. So every gallon of ethanol does not displace a full gallon of gasoline, and burning a gallon of ethanol does not avoid all the CO2 emissions from conventional fuel. The question for more than a decade has been: on which side of the balance sheet does corn ethanol lie. Does it end up saving gasoline or using more? Does it lead to less or more greenhouse gas emissions?

To answer these questions, scientists use a life-cycle or cradle-to-grave assessment. And here is my take on where these assessments lead.

The gasoline savings from corn ethanol appear to be significant. For example, in a paper published in Science in 2006, Alexander Farrell of the University of California, Berkeley, and colleagues estimated that corn ethanol cuts petroleum use by as much as 80 percent or more. (Note that the total energy savings of corn ethanol relative to all fossil fuels used, including natural gas and coal, were estimated to be much more modest.)

corn ethanol is a global warming loser
Will the new biofuels rules proposed by EPA spell trouble for the cozy relationship the corn states have had with the federal government? (NREL)

The stickier question has been whether corn ethanol saves any greenhouse gas emissions. As I described in a previous post, complications arise because the corn that that goes into ethanol is obviously not being used to feed humans or livestock.

In two separate papers published in Science in 2008, Tim Searchinger (from Princeton University) and Joseph Fargione (of The Nature Conservancy) et al. argued that taking cropland out of food production requires converting forest land to cropland (primarily in Brazil) to make up for the food deficit, a conversion that results in huge emissions of CO2 to the atmosphere. The authors calculated that it would take many decades of ethanol use to offset or pay back the greenhouse gas emissions from the destruction of those forests. In other words, from a global warming point of view, corn ethanol is not a winner.

Congress and EPA Take Biofuels into the New Millennium

With the Energy Policy Act of 2005 [pdf] Congress decided to get serious about energy independence, mandating a renewable energy standard requiring ever larger amounts of biofuels in the gasoline sold in the United States with ever larger increases in production from year to year.

In the 2007 Energy Independence and Security Act [pdf], Congress amended the Renewable Fuel Standard to include even more biofuels and went one step further. It added language addressing climate change:

  • The new biofuels requirement mandated that corn ethanol must reduce greenhouse gas emissions by 20 percent.
  • EPA was charged with implementing the program.

Last week, EPA came out with new proposed regulations governing the Renewable Fuel Standard. And lo and behold, they concluded the same thing that Searchinger and colleagues found last year: when land use changes are accounted for, corn ethanol ends up emitting a lot of greenhouse gases. EPA reported results for two scenarios:

  • Over a 30-year horizon, corn ethanol emits five percent more greenhouse gases than conventional gasoline when the ethanol is made using natural gas, and 34 percent more if it is made using coal.
  • Over what seems to me to be a rather long 100-year horizon, corn ethanol reduces greenhouse gas emissions by only about 16 percent, when made using natural gas -- or four percent shy of the Congressional standard. (Ethanol made using coal still emits 13 percent more greenhouse gas than conventional gasoline.)

Corn State Unhappiness?

The corn-producing states are used to special treatment from the federal government. Now, EPA's proposed ruling threatens to shut them out of future biofuels markets.

House Agriculture Chairman Collin Peterson (D-MN) was angered. Upon hearing of the proposal he stated: "I will not support any kind of climate change bill. ... I don't care. Even if you fix this. I don't trust anybody anymore." Somebody needs to find that man a binky.

Will that spell trouble for the Obama administration? Maybe so, if you listen to folks like Robert Dinneen, president of the Renewable Fuels Association, who criticized the proposed rule for not comparing apples to apples (shouldn't that be corn to corn?).

But wait a minute: the administration has moved to soften the blow by announcing a bunch of new federal handouts to the ethanol industry. Will that work? Maybe so if you listen to folks like ... well ...  Robert Dinneen, who praised the administration for sending "an incredibly important signal that biofuels are going to be a key component in his strategy to address energy, economic, and environmental challenges."

Isn't politics great.

Dr. Bill Chameides is the dean of Duke's Nicholas School of the Environment and a member of the National Academy of Sciences. He blogs regularly at