Food production will have to increase in the next 50 years to meet the demand from a growing population and changed food habits, as e.g. for higher meat consumption. The increased production will have to be based on rain-fed agriculture or more effective irrigation strategies, and will have to be mainly in the tropics, since further enhancement in productivity in the western agriculture is a slow process, if possible at all. Climate change will become a major threat to this demand/supply equation, since many new problems will hamper the productivity gain that otherwise could have been...