A surge in global food prices has prompted fresh criticism of U.S. subsidies for ethanol, which diverts massive amounts of corn from global food supplies for energy.
Producers of ethanol argue that the biofuel helps blunt the impact of high imported petroleum prices, but critics say the U.S. policy giving tax breaks for ethanol used in motor fuel ends up being bad for food, energy and the environment.
The issue has created unusual political alliances, with environmental groups and some lawmakers from both parties clashing with farm interests and legislators from the corn-producing Midwest states.
Senators Tom Coburn, a Republican from Oklahoma, and Ben Cardin, a Maryland Democrat, introduced a measure last month to scrap the tax credit of 45 cents per gallon for ethanol in gasoline.
The lawmakers cited a Government Accountability Office report describing the tax credit as "largely unneeded today to ensure demand for domestic ethanol production."
C. Ford Runge, a University of Minnesota professor of applied economics and law, argues that ethanol from crops has many "hidden costs" that should dissuade the government from subsidies.
Runge, who raised concerns about ethanol policy as early as 2007, says his research suggests some 30 percent of food price increases come from diversion of U.S. corn for ethanol.
The U.N.'s Food and Agriculture Organization has warned that rising food prices are driving unrest around the world, including recent uprisings in the Middle East and North Africa.
