Projected water stress in 2040

Based on the ecological footprint model, the water footprint was devised to gain a better understanding of water stress. It includes blue water (pumped from groundwater), green water (used by plants to produce biomass), virtual water (contained in agricultural or manufactured and traded products) and grey water (used to remove pollution from effluents and recycle them). The map is based on data from the American think tank World Resources Institute, and shows water stress projections for 2040, which are arrived at by connecting up the total annual water abstraction and the total renewable resources available each year. The highest figures indicate more competition between users and affect a large section of the global population: the western United States, Mexico, the west coast of Latin America, the Mediterranean region, the Middle East, Western Asia, and the north of China.