‘w A T E ESGT VIEWS
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1 jures ater scarcity typically conup visions of drought,
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those temporary dry spells that nature inflicts from time to time. But while droughts capture headlines and grab our attention, the far greater threat posed by our escalating water consumption goes largely unnoticed. In each area of water use--agriculture, industry, and cities-demands have increased rapidly. Global water use has more than tripled since 1950 and now stands at an estimated 4340 km3per year-eight times the annual flow of the Mississippi River. For decades, planners have met this rising demand by turning to ever more and larger “water development” projects, particularly dams and river diversions. Engineers have built more than 36,000 large dams around the world to control floods and to provide hydroelectric power, irrigation, industrial supplies, and drinking water to an expanding global population and economy. But limits to this ever-expanding supply are swiftly coming to light. Water tables are falling, lakes are shrinking, wetlands are disappearing,and numerous species of aquatic life are at risk of extinction. Engineers propose solving water problems by building ever more mammoth river diversion schemes, with exorbitant price tags and damaging Views am insightful commentaries on timely environmental topics, represent an author’s opinion, and do not necessarilyrepresent a position of the society or editors. Contrasting views ore in-
environmental effects. Around Beijing, New Delhi, Phoenix, and other water-short cities, competition is brewing between city dwellers and farmers who lay claim to the same limited supply.And people in the Middle East have heard more than one leader voice the possibility of going to war over scarce water. Perhaps the clearest sign of water scarcity is the increasing number of countries in which population has surpassed the level that can be sustained comfortably by the water available. As a rule of thumb, hydrologists designate water-scarce countries as those with annual supplies of less than 1000 m3 per person. Today, 26 countries, collectively home to 232 million people, fall into that category. Africa has the largest numher, 11 in all. By 2010, six others will join the list, and the total number of Africans living in water-scarce countries will climb to 400 million, or 37% of the continent’s projected population. Nine out of 14 countries in the Middle East already face water-scarce conditions, making it the most concentrated region of water scarcity in the world. Because populations in several Middle Eastern countries are projected to double within 25 years, a rapid tightening of supplies is inevitable. Meeting human needs while facing up to water’s limits-economical, ecological, and political-entails developing a wholly new relationship to water. Historically, we have managed water with a frontier philoso-
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