As if rising food prices was not hard enough on the poor, a new report states that in many developing countries, the push towards bio-fuels will push poor people off of their lands, compounding their problems.
So, here we have a fuel that is highly inefficient, results in hardly any carbon savings (AAMOF, I have seen arguments that when the in-efficiencies in production are properly factored in (that is, the pollution involved in growing the base grains required), the use of bio-fuels is actually worse for the environment), drives up the cost of food, may drive up the cost of petroleum, and may start pushing poor people off of their land.
All in all, I think the last line of the linked article says it all:
"The policy on biofuels is currently running ahead of the science."