"Food security will deteriorate further unless leading countries can collectively mobilize to stabilize population, restrict the use of grain to produce automotive fuel, stabilize climate, stabilize water tables and aquifers, protect cropland, and conserve soils." — Lester Brown, World Facing Huge New Challenge on Food Front
Chapter 2. Emerging Water Shortages: Introduction
The world is incurring a vast water deficit—one that is largely invisible, historically recent, and growing fast. Because the impending water crunch usually takes the form of aquifer overpumping and falling water tables, it is often not apparent. Unlike burning forests or invading sand dunes, falling water tables cannot be readily photographed. They are often discovered only when wells go dry.
Newspapers carry frequent accounts of rivers failing to reach the sea, or lakes disappearing, or wells going dry, but these stories typically describe local situations. It is not until we begin to compile the numerous national studies—such as a 748-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.1
The world water deficit is recent—a product of the tripling of water demand over the last half-century and the worldwide spread of powerful diesel and electrically driven pumps. The drilling of millions of 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 scores of countries. The mining of groundwater is quite literally undermining the future of some countries.2
Rivers running dry are far more visible. Among the rivers that now fail to reach the sea all or part of the time are the Colorado, the major river in the southwestern United States; the Yellow River, the cradle of Chinese civilization; and the Amu Darya, one of the two rivers that feed the Aral Sea in Central Asia. Other major rivers that have been reduced to a trickle when they reach the sea include the Nile, the Indus, and the Ganges.3
Water shortages are generating conflicts between upstream and downstream claimants, both within and among countries. For the Yellow River, the competition is between impoverished upstream provinces and more prosperous coastal provinces. For the Nile, competition is among countries, principally Egypt, the Sudan, and Ethiopia, where much of the Nile's flow originates.4
Water scarcity, once a local issue, is now crossing international boundaries 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, then importing grain to offset the loss of productive capacity. Because it takes 1,000 tons of water (1,000 cubic meters) to produce 1 ton of grain, importing grain is the most efficient way to import water. Countries are now satisfying their growing demand for water by tapping international grain markets. As water shortages intensify, so too will the competition for grain in these markets. In a sense, to trade in grain futures is to trade in water futures.5
The link between water and food is a strong one. Our individual daily water requirements for drinking average 4 liters per day, while the water required to produce our food each day totals at least 2,000 liters—500 times as much. In affluent societies, where grain is consumed in the form of livestock products, water consumed as food can easily reach 4,000 liters daily.6
Worldwide, 70 percent of all the water diverted from rivers or pumped from underground is used for irrigation. Twenty percent is used by industry and 10 percent for residential purposes. With the demand for water growing steadily in all three sectors, competition is intensifying. In this struggle for water, farmers almost always lose to cities and industry.7
1. 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).
2. Water use from Peter H. Gleick, The World's Water 2000-2001 (Washington, DC: Island Press, 2000), p. 52.
3. Colorado, Nile, Indus, and Ganges rivers from Sandra Postel, Pillar of Sand (New York: W.W. Norton & Company, 1999), pp. 71-73, 261-62; Yellow River from World Bank, op. cit. note 1, p. viii; Aral Sea from U.N. Environment Programme (UNEP), Afghanistan: Post-Conflict Environmental Assessment (Geneva: 2003), p. 60.
4. For a chronology of water conflicts, see Peter H. Gleick, The World's Water 2002-2003 (Washington, DC: Island Press, 2002), pp. 194-208.
5. Water-to-grain conversion from U.N. Food and Agriculture Organization (FAO), Yield Response to Water (Rome: 1979).
6. Jacob W. Kijne, Unlocking the Water Potential of Agriculture (Rome: FAO, 2003), p. 26.
7.Water use from Gleick, op. cit. note 2.
Copyright © 2003 Earth Policy Institute