A World of Thirst
Poor sanitation. Pollution. Wasteful irrigation. The planet's freshwater supply is terribly managed
Over the course of the past 40 years, north Africa's Lake Chad has shriveled to one tenth its earlier size, beset by decades of drought and agricultural irrigation that have sucked water from the rivers that feed iteven as the number of people whose lives depend on its existence has grown. In 1990, the Lake Chad basin supported about 26 million people; by 2004 the total was 37.2 million. In the next 15 years, experts predict, the incredible shrinking lake and its tapped rivers will need to support 55 million. "You don't have much room for error at this point," says hydrologist Michael Coe.
The population growth has coincided with a 25 percent decrease in rainfall, with global warming very likely a factor. As oceans store more heat, the temperature difference between water and land dissipates, sapping power from rainmaking monsoons. At the same time, desperate people are overusing wells. Coe recently concluded that water supplies in the basin are "stretched to their limits, and future needs will far outstrip the accessible supply."
Lake Chad, with its confluence of troubles, is emblematic of a burgeoning water crisis around the world. While the western United States faces serious water problems, American money and know-how can at least soften the blow. Not so elsewhere. Worldwide, 1.1 billion people lack clean water, 2.6 billion people go without sanitation, and 1.8 million children die every year because of one or the other, or both. By 2025, the United Nations predicts 3 billion people will be scrambling for clean water. There are myriad problems: industrial contaminants flooding waterways, wasteful irrigation, an exploding world population, political corruption and incompetence, and a changing climateto name a few.
In a report issued in November, the United Nations declared water "a global crisis," announcing that 55 member nations are failing to meet their water-related Millennium Development Goal target, agreed upon in 2000, of halving the proportion of people without clean water and sanitation by 2015. The real crisis, experts say, is not a lack of water but a lack of water management. Water doesn't always appear in the right places, or at the right times. And it has to be cared for. "It's a terrible situation around the world," says Peter Rogers, a Harvard environmental engineering professor, "but it doesn't have to be."
One percent. Just 3 percent of the world's water is fresh. Of that, most is locked in the ground, glaciers, or ice caps. That leaves about 1 percent for the world's 6.6 billion people. As population grows, so does demand for waterbut at two to three times the rate. People consume water for drinking, for hygiene, through food production, and in a variety of industrial processes. A blossoming middle class in Southeast Asia, India, and China will join the West in consuming far more than the minimum 20 to 50 liters (about five to 13 gallons) of water per day necessary per person. (Americans lead the world by consuming 400 to 600 liters per day, or as much as 158 gallons.) Upward mobility has yielded more flush toilets and a dietary shift from grain to meat-heavy diets. Raising a cow requires a thousand times more water than the equivalent average for grain.