CEI put out a study recently on just what an expanded ethanol requirement would mean. Here’s one of the main conclusions:

The United States might well have to clear an additional 50 million acres of forest—or more—to produce economically significant amounts of liquid transport fuels. Despite the legend of past U.S farm surpluses, the only large reservoir of underused cropland in America is about 30 million acres of land—too dry for corn—enrolled in the Conservation Reserve. Ethanol mandates may force the local loss of many wildlife species, and perhaps trigger some species extinctions. Soil erosion will increase radically as large quantities of low-quality land are put into fuel crops on steep slopes and in drought-prone regions.

Green environmentalists like Lester Brown and George Monbiot are right on ethanol – it comes with environmental consequences of its own, no matter how efficient the conversion plants are. Free-market environmentalists like me are happy to recognize that.