85% of the world population lives in the driest half of the planet. 783 million people do not have access to clean water and almost 2.5 billion do not have access to adequate sanitation. Various estimates indicate that, based on business as usual, ~3.5 planets Earth would be needed to sustain a global population achieving the current lifestyle of the average European or North American.
Water availability is expected to decrease in many regions. Yet future global agricultural water consumption alone is estimated to increase by ~19% by 2050, and will be even greater in the absence of any technological progress or policy intervention.
Water for irrigation and food production constitutes one of the greatest pressures on freshwater resources. Agriculture accounts for ~70% of global freshwater withdrawals (up to 90% in some fast-growing economies).
About 66% of Africa is arid or semi-arid and more than 300 of the 800 million people in sub-Saharan Africa live in a water-scarce environment – meaning that they have less than 1,000 m3 per capita (NEPAD, 2006).