Argument: Converting grass into fuel is tremendously inefficient
Robert Bryce. "The Cellulosic Ethanol Mirage: Verenium and Aventine Are Circling the Drain." Energy Tribune. Mar. 30, 2009: "Despite the hype, cellulosic ethanol is no closer to commercial viability than it was when Midgley first began talking about it back in 1921. Turning switchgrass, straw or corn cobs into sizable volumes of motor fuel is remarkably inefficient. It is devilishly difficult to break down cellulose into materials that can be fermented into alcohol. And even if that process were somehow made easier, its environmental effects have also been called into question. A September 2008 study on alternative automotive fuels done by Jan Kreider, a professor emeritus of engineering at the University of Colorado, and Peter S. Curtiss, a Boulder-based engineer, found that the production of cellulosic ethanol required about 42 times as much water and emitted about 50 percent more carbon dioxide than standard gasoline. Furthermore, Kreider and Curtiss found that, as with corn ethanol, the amount of energy that could be gained by producing cellulosic ethanol was negligible."