"Eliminating water shortages depends on a global attempt to raise water productivity similar to the effort launched a half-century ago to raise land productivity, an initiative that has nearly tripled the world grain yield per hectare." –Lester R. Brown, World Facing Huge New Challenge on Food Front in Plan B 3.0: Mobilizing to Save Civilization
Chapter 3. Emerging Water Shortages: Introduction
Africa’s Lake Chad, once a landmark for astronauts circling the earth, is now difficult for them to locate. Surrounded by Chad, Niger, and Nigeria—three countries with some of the world’s fastest-growing populations—the lake has shrunk by 95 percent since the 1960s. The soaring demand for irrigation water in that area is draining dry the rivers and streams the lake depends on for its existence. As a result, Lake Chad may soon disappear entirely, its whereabouts a mystery to future generations. 1
Every day, it seems, we read about lakes disappearing, wells going dry, or rivers failing to reach the sea. But these stories typically describe local situations. It is not until we begin to compile the numerous national studies—such as an 824-page analysis of the water situation in China, a World Bank study of the water situation in Yemen, or a detailed U.S. Department of Agriculture (USDA) assessment of the irrigation prospect in the western United States—that the extent of emerging water shortages worldwide can be grasped. Only then can we see the extent of water overuse and the decline it can bring. 2
The world is incurring a vast water deficit—one that is largely invisible, historically recent, and growing fast. Because much of the deficit comes from aquifer overpumping, it is often not apparent. Unlike burning forests or invading sand dunes, falling water tables are often discovered only when wells go dry.
This global water deficit is recent, the result of demand tripling over the last half-century. The drilling of millions of irrigation wells has pushed water withdrawals beyond the recharge of many aquifers. The failure of governments to limit pumping to the sustainable yield of aquifers means that water tables are now falling in countries that contain more than half the world’s people. 3
Among the more visible manifestations of water scarcity are rivers running dry and lakes disappearing. A politics of water scarcity is emerging between upstream and downstream claimants both within and among countries. Water scarcity is now crossing borders via the international grain trade. Countries that are pressing against the limits of their water supply typically satisfy the growing need of cities and industry by diverting irrigation water from agriculture, and then importing grain to offset the loss of productive capacity.
The link between water and food is strong. We each drink on average nearly 4 liters of water per day in one form or another, while the water required to produce our daily food totals at least 2,000 liters—500 times as much. This helps explain why 70 percent of all water use is for one purpose—irrigation. Another 20 percent is used by industry, and 10 percent goes for residential purposes. With the demand for water growing in all three categories, competition among sectors is intensifying, with farmers almost always losing. 4
1. M.T. Coe and J.A. Foley, “Human and Natural Impacts on the Water Resources of the Lake Chad Basin,” Journal of Geophysical Research (Atmospheres), vol. 106, no. D4 (2001), pp. 3349–56; Lynn Chandler, “Africa’s Lake Chad Shrinks by 20 Times Due to Irrigation Demands, Climate Change,” press release (Greenbelt, MD: NASA, Goddard Space Flight Center, 27 February 2001); population information from United Nations, World Population Prospects: The 2004 Revision (New York: February 2005).
2. World Bank, China: Agenda for Water Sector Strategy for North China (Washington, DC: April 2001); Christopher Ward, The Political Economy of Irrigation Water Pricing in Yemen (Sana’a, Yemen: World Bank, November 1998); U.S. Department of Agriculture (USDA), Agricultural Resources and Environmental Indicators 2000 (Washington, DC: February 2000).
3. Water use tripling from I.A. Shiklomanov, “Assessment of Water Resources and Water Availability in the World,” Report for the Comprehensive Assessment of the Freshwater Resources of the World (St. Petersburg, Russia: State Hydrological Institute, 1998), cited in Peter H. Gleick, The World’s Water 2000–2001 (Washington, DC: Island Press, 2000), p. 52.
4. Jacob W. Kijne, Unlocking the Water Potential of Agriculture (Rome: FAO, 2003), p. 26; water use from Shiklomanov, op. cit. note 3, p. 53.
Copyright © 2006 Earth Policy Institute