With bombs dropping in the Middle East and gas pump prices topping $3 a gallon, biofuels are being hailed as the great green hope for an alternative energy policy. But some environmentalists are starting to raise a red flag.

Writing for Environmental Science and Technology, editor Jerald L. Schnoor acknowledges the benefits of ethanol and biodiesel: They strengthen the farm economy and make the United States less dependent on foreign oil. Those pluses, though, have a negative side, says Schnoor. For example, current row-crop agriculture saps nutrients from the land and erodes the soil to a degree that makes the method unsustainable.

Julia Olmstead, a graduate fellow with the Land Institute in Salina, Kansas, created a ripple of realization with her recent article in the Prairie Writers Circle, 'The Biofuel Illusion.' An economy based on biofuels is flat-out unrealistic, Olmstead argues. 'To produce enough corn-based ethanol to meet current US demand for automotive gasoline,' Olmstead writes, 'we would need to nearly double the amount of land used for harvested crops, plant all of it in corn, year after year, and not eat any of it.' And keep in mind, she notes, those farm operations rely heavily on fossil fuels to run farm machinery.

Furthering the case against biofuel, Lester R. Brown, founder and president of the Earth Policy Institute, predicts in the organization's Eco-Economy Update that the gasoline alternative will drive up the cost of food. This already has happened with sugar, one source for ethanol. The price of sugar has doubled since producers began redirecting their harvests toward ethanol production, which now accounts for 10 percent of the world's harvest. Brown points out that most ethanol in the United States is produced from corn, a plant not only eaten by the nation's citizens, but by livestock as well. With increased demand, the price of corn and meat likely will soon be on the rise. Will grocery shoppers stand a chance against the subsidized ethanol industry? Will less affluent nations suffer as food crops are rededicated to fuel cars?