Evidence debatable on greenness of corn ethanol

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BY JOE DUGGAN / Lincoln Journal Star

Is corn ethanol truly green?

It’s a tough question to answer, because supporters and detractors of the biofuel can cite legitimate scientific studies to support their positions. Plus, the question involves many effects on air, water and land, which means no single test or standard can be applied to declare ethanol all good, or all bad, for the environment.

Some environmental advocates bash ethanol outright, but most believe it represents an important first step in building a system that moves away from fossil fuels. Still, they argue, the public needs to understand the limitations and environmental costs of ethanol, which are often brushed off by policymakers and politicians who trumpet the economic benefits of the fuel.

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Ethanol and the environment

(Illustration by Kim Stolzer, animation by Laura Meerkatz / JournalStar.com)...

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Here’s a quick summary of the main flash points in the debate over ethanol and the environment:

Energy balance

* Most studies show ethanol generates more energy in automobiles than it takes to grow corn, distill alcohol and transport the fuel to market, according to a 2006 analysis of such studies published in the Journal of Cleaner Production.

In other words, the fuel produces a net gain in energy balance, albeit a small one.

* Hogwash, says Tad Patzek, a geoengineering professor at the University of California-Berkeley.

When the energy required to grow seed and make fertilizer and other ag chemicals is factored in, Patzek has said, it takes six times as much energy to make ethanol than ethanol yields.

Emissions

* Ethanol fuels produce less carbon monoxide, cancer-causing emissions and particulate matter, says the National Corn Growers Association.

Also, the fuel releases a lower volume of greenhouse gases than regular gasoline, according to the Renewable Fuels Association. A study at the Argonne National Laboratory in Illinois found that in 2006, E10

(10 percent ethanol/90 percent gasoline) use in the United States reduced carbon dioxide-equivalent greenhouse gas emissions by about 8 million tons, equal to removing the annual emissions of more than 1.21 million cars from the road.

* The scientific community holds differing views over the emissions question.

Mark Jacobson, a Stanford University civil and environmental engineering professor, ran a computer model this year that shows burning E85 fuel (85 percent ethanol/15 percent gasoline) increases smog, and therefore, smog-related deaths. Burning E85 produces more ozone, a major component of smog, Jacobson found.

* One reputable analysis says E85 also produces greater volumes of gases that contribute to the greenhouse effect, according to a 2006 analysis published in the Proceedings of the National Academy of Sciences.

Biodegradable fuel

* Alcohol biodegrades faster than the chemicals and compounds in gasoline.

Because it occurs naturally in the environment, alcohol also is considered nontoxic — at least in small quantities, according to the National Corn Growers Association. So, while a large spill of ethanol wouldn’t be good, it wouldn’t be as bad as an equivalent spill of gasoline.

Changing the landscape

* Farmers are planting more corn to capitalize on higher prices.

The 11 million acres of corn estimated in Nebraska this year represent an increase of 1.1 million acres over 2006 and the most corn acres since 1936. All corn-growing states are seeing similar trends, which the U.S. Department of Agriculture has attributed to ethanol demand.

* More corn means more ag chemicals in the environment. Nitrogen fertilizer, phosphorus and pesticides all can run off. In fact, studies have shown that close to half of the fertilizer applied in farm fields runs off into nearby streams.

* More corn acres also means more irrigation. Those who study Nebraska’s underground water supply say this is their most pressing concern about the ethanol boom.

* Wildlife conservationists fear a loss of grasslands in Nebraska and other states as landowners till ground for additional corn production. Current grain prices certainly are more lucrative than payments landowners earn through the federal Conservation Reserve Program.

* Ethanol advocates counter that corn is a renewable resource, unlike fossil fuels. And corn plants capture CO2 during growth, essentially recycling a major greenhouse gas released during fuel combustion.