Corn Ethanol Investigated

Just like cholesterol, there's the good kind and the bad kind when it comes to ethanol. While ethanol is often promoted by politicians as a solution to our dependence on foreign oil, corn ethanol (the type of ethanol slated for large government subsidies) seems to be worse in terms of fuel efficiency, much worse in terms of toxic formaldehydes, and only slightly better in terms of greenhouse gas emissions.
The Union of Concerned Scientists reports that the energy required to grow corn crops and produce corn ethanol, is about the same as the fuel's energy output. It's a break-even proposition at best. So while corn ethanol is not a long-term solution, it could provide a bridge to cellulosic ethanol, which is much more sustainable.

Cellulosic ethanol (the good kind) provides a solution -- it is produced from agricultural byproducts (such as corn stalks) so does not cause additional greenhouse gases. The biofuel company Verenium is on the forefront of developing enzymes that can digest cellulose, so cellulosic ethanol may soon be a viable alternative for producing renewable fuel in agricultural regions.

Watch an ABC News video about the controversy around corn ethanol, which investigates some of the problems with Corn ethanol, and the reason why the industry needs to be subsidized.