At the behest of Corn Belt lawmakers, Congress has already done hugely lucrative favors for the ethanol industry. These include a 51-cent-a-gallon federal subsidy, an ethanol-usage requirement that has artificially inflated demand and price, and a 54-cent-a-gallon tariff on competing Latin American ethanol brewed from sugar cane.

The energy bill now before Congress offers more of the same. The most harm could come from yet another mandate to drastically increase ethanol consumption – a market intervention that will again drive up prices and deliver a windfall to agribusiness.

In theory, ethanol is a cleaner alternative to gasoline that could help the United States become less dependent on foreign oil. That theory will become reality when ethanol can be economically fermented from such cheap, high-cellulose sources as wood chips, poplar trees, switchgrass and the like.

But corn ethanol, as a solution to America’s energy problems, is a disaster.

Let us count the ways:

 • To produce it, you grow lots and lots of corn – a crop that needs large amounts of energy, water and fertilizer. Only the federal subsidies make corn ethanol “competitive” on a large scale.

 • Enormous quantities of fossil fuels are burned growing, harvesting and transporting corn. For every gallon’s worth of energy it yields, it takes most of a gallon to produce. The fossil fuels burned, of course, release greenhouse gases.

 • Ethanol production has been driving up the price of food by cutting the supply of corn for livestock feed and reducing harvests of other crops displaced by corn. It has particularly hurt Mexico, where the price of tortillas has been forced up by the diversion of U.S. corn.

 • With the subsidized expansion of corn crops has come an expansion of the use of phosphorus and nitrogen to fertilize cornfields. In some areas, the runoff of these chemicals has badly polluted streams, rivers or lakes.

All biofuels are not created equal. It’s foolish to treat corn ethanol as if it were as genuinely promising a source of energy as, say, biodiesel or cellulosic ethanol. The world needs the corn American farmers grow – for food, not fuel.