Ensuring that the world's food needs are met by 2050 will take a doubling of global food production. To improve agricultural yields on that scale will require a radical rethink of global water-management strategies and policies.
Sub-Saharan Africa is the epicentre of this challenge. The region's population is set to more than double by 2050 to almost 2.5 billion, or 25% of the world's projected population. Half of its current one billion inhabitants lives in extreme poverty, one-quarter is undernourished, and one-fifth faces serious water shortages. Although almost two-thirds of the population are rural, agriculture on much of the land is limited by scarce, variable and unpredictable water resources.