an Oak Ridge National Laboratory study (without taking from the food supply). Now, this is considering the development of cellulosic ethanol. Corn based (and sugar cane, sugar beets, etc) will not replace a large amount of the gasoline given current technology(although, Iowa State University has filed for a patent for a process using ultra-sound which boost alcohol yield from corn by about 30% (
http://www.sciencedaily.com/releases/2006/06/060601213717.htm).
But it is the quickest and most cost effective way we currently have to replace some of the gasoline and reduce our imports of oil. In about 5 to 6 years cellulosic ethanol should be cost effective and ready to be scaled up. I think the 12% figure mentioned is without touching food supplies. (but check below re cotton export subsidies)
Currently, ethanol represents about 3% of the total supply of gasoline (this takes about 12% of the acres devoted to growing corn). The production capacity under construction at the end of 2005 represented about a 62% increease in production capacity. Most of this will be coming on line during 2006. Currently, the oil companies are buying up ethanol to replace MTBE in gasoline. When this is accomplished ethanol will be 6% to 10% of the gasoline, depending on your location.
The increased production and availability of ethanol could be accelerated if there was interest in supporting it more aggressively at the national level. Considering the economic (balance of trade) and security implications (possibility of oil supply disruption) it's surprising we do not have more of a national initiative for increasing ethanol availability and supply.
for what it's worth, the World Trade Organization found the U.S. guilty of using export subsidies (costing $4 Billion per year) to support our cotton growers which enabled them to compete in world markets. Congress has sent up a bill to Bush for signature which would end export subsidies to cotton. Now, if he should deign to sign it, cotton would no longer be a profitable crop for farmers to grow and they would have to look for some other crop to grow. Given the tremendous demand for corn for ethanol they are likely to go to planting feed lot corn for ethanol. Given that the number of acres planted to cotton is about equal to the number of acres planted in corn for ethanol, if most cotton farmers chose to plant corn for ethanol this would mean about a 100% increase in the supply of corn for ethanol.
..if Bush signs the bill ending the $4 Billion dollar annual subsidies to cotton.