As biofuels continue to get battered for all sorts of evils, discussions at a U.N. summit in Rome have turned to emerging technologies such as creating fuel from plant waste rather than the crops themselves.

The summit is considering a draft declaration that would urge more research into non-food biofuel crops, such as jatropha trees, and “second-generation technologies … which are focused on cellulose from stalks and leaves rather than food sources”. Such new fuels would shift away from crops such as corn, wheat, maize, soya, palm oil or sugar, blamed for driving up food prices alongside factors such as a rising human population, changing diets, high oil prices and bad weather.