About one-third of the world’s population lives in countries suffering from moderate-to-high water stress—where water consumption is more than 10 per cent of renewable freshwater resources. Some 80 countries, constituting 40 per cent of the world’s population, were suffering from serious water shortages by the mid-1990s. Global per capita water supplies decreased by one-third between 1970 and 1990 and are likely to drop by a third over the next 20 years. Increasing water demand has been caused by population growth, industrial development, and the expansion of irrigated agriculture. China, for all these reasons, now faces severe water shortages in the northern part of the country, and thus provides a case study of freshwater shortage worldwide.