"The headlong rush in many parts of the world to replace oil with biofuels (ethanol and biodiesel) illustrates how the best of intentions can run afoul of the law of unintended consequences. While positive effects have been elusive -- and, in fact, are unlikely with current policies -- starvation and malnourishment are becoming worse among the poorest of the poor.
The reality is that with current technology, almost all of this biofuel would have to come from corn because there is no other feasible, proven alternative. But because of the inefficiencies inherent in producing ethanol from corn and the relatively meager amount of energy yielded by burning ethanol, the demands on farmland would be staggering. An analysis by the Paris-based Organization for Economic Cooperation and Development suggested that replacing even 10 percent of America's motor fuel with biofuels would require that about a third of all the nation's cropland be devoted to oilseeds, cereals and sugar crops. Achieving the 15 percent goal would require the entire current U.S. corn crop, which represents a whopping 40 percent of the world's corn supply."
I know this has been over-discussed, but every little bit helps.