@ Amphibious54- Although ethanol is considered a renewable resource, it is only marginally so. In addition, the use of ethanol as an alternative renewable energy source is hardly sustainable.
There are a few major areas of concern with ethanol production in its current state:
1) Ethanol crops are also food crops, causing the price of food to skyrocket.
2) Ethanol does not decrease demand for liquid fuels.
3) Ethanol production is a main cause of the deforestation of the Amazon and Borneo rainforests.
4) Ethanol production only creates marginal gains in reducing carbon emissions.
There are other issues with current biofuel technology, but these are the big ones. The amount of food crops needed to fill a tankful of ethanol in an E85 Suburban is enough to feed an African village for over a year and a half (approx. half ton of corn per 39-gallon fuel tank). Facts like these make food-based biofuels not worth the trouble.