While biologists say a lot of other plant material from wild grass to weeds could be used to brew ethanol, the industry so far is set up around corn. Dennis Keeney, a senior fellow at the Institute for Agriculture and Trade Policy, says he doesn’t think the explosion of corn production will continue indefinitely.

He sees the corn industry "settling down" to a steady production of ten to fifteen-Billion gallons of ethanol a year. It’s a good fuel for increasing the octane rating of fuel, he says, and while corn will probably always be used to make ethanol he sees a future for other cellulosic sources of ethanol that can be made from "long-lasting plants" that would help control erosion.

"In the end…I think we cannot ‘grow ourselves out’ of this problem," Keeney says. He says the trouble is with our habits of consumption and they cannot be supported in our current system. "The world is not sustainable as it’s going right now." Keeney says growing corn to try and meet the nation’s energy needs will have an impact on everything from the size of farms to water supplies and bio-diversity.

"The concern is building and it’s not just me," Keeney says. "It’s a widespread concern." He says some countries have considered a moratorium on building new ethanol plants until the market settles down, though he says it hasn’t happened in the United States and probably won’t.

An international expert in sustainable farming and pioneering environmental scientist in water quality, Keeney is former director of Iowa State University’s Leopold Center for Sustainable Agriculture. Keeney spoke at the University of Iowa today.