No such thing as a free (or even cheap) lunch

We read in the papers of biofuels replacing petroleum. Now the Financial Times reports that food prices are experiencing their biggest increases in 30 years ("Fears over food price inflation"), fueled by expanding use of biofuels, climate change, and growing prosperity in India and China.

Maybe conservation will have to play a bigger role compared to substitution than we may have thought (or at least than we act as if we thought).