Narrator: This is Science Today. University of California, Berkeley, geoengineering professor, Tad Patzek has found that using ethanol from corn, a gas additive, spends more energy than it saves. Patzek calculated that the energy spent growing corn, converting it to ethanol and shipping it was more than the energy the ethanol would provide once in use.

Patzek: We use more resources, both in terms of fuels and in terms of minerals, soil, clean water and air, than we produce useful work out of corn ethanol.

Narrator: U.S. policymakers are currently working with farmers to ramp up corn production, in an effort to double the use of ethanol as a gas additive by 2012.

Patzek: If you were to convert all the corn in the United States that was produced in 2004, which was the record crop ever in the history of the United States, you would satisfy at most 15 percent of the US gasoline consumption, and you cannot convert all the corn because you have to use it for other uses like feeding people and animals.

Narrator: For Science Today, I'm Larissa Branin.