Rodrigo Wagner and I have estimated that there are some 95 countries that have more than 700m hectares of good quality land that is not being cultivated. Depending on assumptions about productivity per hectare, today’s oil production represents the equivalent of some 500m to 1bn hectares of biofuels. So the production potential of biofuels is in the same ball park as oil production today.
...Biofuels policy needs to stop being seen through the prism of agricultural support policy – which justifies a 54 cents a gallon US tariff on Brazilian ethanol – and instead become the purview of energy and environmental policies.
I've been a big biofuels skeptic, because of all the subsidies and rent-seeking involved. But read the entire article. As Tyler Cowen says, it goes against one's mental model.
The MIT guys say that we should not be prejudiced against any form of energy, because we are going to need everything--conservation, coal, nuclear, biomass, etc.