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 achieved. Simple movement of genetic material or management techniques (North ? South or South ? North) to overcome future climate change, are doubtful, since photoperiodic control of most tropical species are very strong. Establishing more local breeding programs in a wider number of tropical species than currently, is highly relevant for continuously adapting to changing climate. Apart from crop breeding, many new research areas within plant physiology needs further work.