"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
Part 1. Deserts Invading China: From Ecological Deficits to Dust Bowl
As noted earlier, several ecological deficits are converging in China to create a dust bowl on a scale never before witnessed. In its effort to remain self-sufficient in grain, China has tried to avoid any shrinkage in overall cultivated area. As industrialization has claimed cropland in the coastal provinces, the national policy has offset these losses with the cultivation of land elsewhere. Thus the cultivated area in some northern provinces expanded during the 1990s. In Inner Mongolia, for example, it grew by an astonishing 22 percent between 1987 and 1996. 19
China’s expanding demand for food has pushed agriculture onto marginal land in the northwestern provinces, much of it land too dry to sustain cultivation. As a result, the soil is blowing away and the land is losing its productivity. Eventually the unproductive cropland is abandoned. Traveling by train through northern and western China in May 2002, I saw many such plots of abandoned land.
Overgrazing may be even more damaging. China’s herds of cattle and flocks of sheep and goats have outgrown the carrying capacity of rangelands, leading to a forage deficit. After the 1978 economic reforms, when China shifted to a market economy, the government lost control of livestock numbers. As a result, the livestock population has grown by leaps and bounds, far exceeding that of the United States, a country with a comparable grazing capacity. While the United States has 97 million cattle, China has 128 million. The United States has 8 million sheep and goats; China has a staggering 290 million. The sheep and goats that range across the land are simply denuding western and northern China, a vast grazing commons. In China, as in many other countries with common grazing areas, there is no administrative mechanism for limiting livestock populations to the sustainable yield of rangelands. 20
A report by a U.S. embassy official in May 2001 after a visit to Xilingol Prefecture in Inner Mongolia notes that official data classify 97 percent of the prefecture’s 200,000 square kilometers as grassland, but a simple visual survey indicates that a third of the terrain appears to be desert. A similar survey by an aid official for another prefecture in Inner Mongolia indicates that half of the land is now desert. The embassy report on Xilingol describes the livestock population in the prefecture jumping from 2 million as recently as 1977 to 18 million in 2000. (See Table 1–2.) 21
The report notes that whereas the traditional nomadic herders kept a mix of horses, cattle, sheep, and goats, today’s herds consist overwhelmingly of sheep and goats. And People’s Daily reports that the yield of forage from Inner Mongolia’s rangelands has declined by at least 30 percent, and perhaps as much as 70 percent, over the last half-century. A Chinese scientist doing grassland research in Xilingol estimates that if recent trends of desertification continue, Xilingol will be uninhabitable in 15 years. 22
As China’s population has grown, so too has the demand for fuelwood and lumber. Throughout most of the country, this demand now exceeds the sustainable growth of trees and shrubs. As a result, vegetation has disappeared in many areas, leaving little to hold the soil when the wind blows or when it rains. 23
Deforestation of the southern provinces may also be reducing the amount of rainfall recycled into the interior of the continent. The Yangtze River basin, for example, which occupies much of southern China, has lost 85 percent of its original tree cover. In these circumstances, when moisture-laden air masses move inland from the sea, the rainfall they produce quickly runs off, returning to the sea. When this land was heavily forested, most of the rainfall was retained and evaporated either directly into the atmosphere or indirectly through the transpiration of the trees, to be carried further inland. As Wang Hongchang of the Chinese Academy of Social Sciences points out, the diminished capacity of the deforested land to recycle water inland may be reducing rainfall in the northwestern interior of China. 24
China is incurring another costly ecological deficit as the use of water for irrigation, industry, and residential use climbs, exceeding aquifer recharge. When the rising demand for water approaches the sustainable yield of aquifers, governments can avoid overpumping by investing in efforts to stabilize population and by raising water productivity. Unfortunately, the sustainable-yield threshold of aquifers is usually ignored. As a result, water tables are falling throughout the northern half of China as pumping exceeds the natural recharge from precipitation. As the water levels fall, the springs that feed streams dry up. And then the rivers they feed go dry. Lakes disappear. In the northern half of China, thousands of lakes have vanished over the last few decades. 25
A World Bank study of key river basins that make up much of the North China Plain—the Hai, which contains both Beijing and Tianjin, two of China’s largest industrial cities; the Yellow, which originates on the Tibet-Qinghai plateau and eventually empties into the Yellow Sea; and the Huai, the next river basin south—found that the three together have an annual deficit of 37 billion tons of water. 26
Assuming 1,000 tons of water to produce 1 ton of grain, this water deficit is equal to 37 million tons of grain, which at current consumption levels is enough to feed 111 million Chinese. Stated otherwise, 111 million Chinese are being fed with grain produced with the unsustainable use of water. Not only is this water deficit large, but it is growing progressively larger. With virtually all water now spoken for in northern China, the growing demand for water in cities and industry is satisfied by taking irrigation water from agriculture. For example, rice production is being phased out in the region surrounding Beijing and farmers are shifting to less water-intensive crops simply because the water is needed for the city, which now has 10 million people. 27
The first three ecological deficits—overplowing, overgrazing, and overcutting—are destroying the vegetation that protects the soils of China. The fourth—overpumping—is drying out the land. Water shortages also make any water-dependent reclamation efforts, such as tree planting, more difficult, accelerating the desertification process.
In addition to the four ecological deficits just described, the worldwide rise in temperature may also be contributing to the desertification of China. Higher temperatures appear to be raising evaporation rates and drying out the country’s interior. Warmer winters both reduce snow cover and lead to the earlier loss of snow cover in the spring, which may explain why the dust storms have started earlier in recent years. Simply stated, China may also be battling the effects of global warming. 28
China’s ecological deficits reflect three dangerous weaknesses of markets: their inability to recognize and respect the sustainable-yield thresholds of natural systems; their inability to value nature’s services, such as the role of natural vegetation in protecting the land; and their inability to incorporate the indirect environmental costs of various economic activities, such as overplowing. Driven by a combination of population and income growth, these ecological deficits are setting the stage for an ecological meltdown in China on a scale that has no historical precedent.
|Table 1-2. Livestock Population of Xilingol Prefecture, Inner Mongolia, 1977-2000|
|Source: "Grapes of Wrath in Inner Mongolia," report from the U.S. Embassy in Beijing, May 2001.|
19. Hong Yang and Xiubin Li, “Cultivated Land and Food Supply in China,” Land Use Policy, vol. 17, no. 2 (2000).
20. U.N. Food and Agriculture Organization (FAO), FAOSTAT Statistics Database, at <www.apps.fao.org>, updated 28 May 2002.
21. “Grapes of Wrath in Inner Mongolia,” op. cit. note 4.
23. Wood demand from FAO, op. cit. note 20, updated 19 December 2001.
24. Tree loss from Carmen Revenga et al., Watersheds of the World (Washington, DC: World Resources Institute and Worldwatch Institute, 1998); Wong Hangchang, “Deforestation and Desiccation in China: A Preliminary Study,” study for the Beijing Center for Environment and Development, Chinese Academy of Social Sciences (Beijing: 1999).
25. Economist Intelligence Unit, “China Industry: Heavy Usage, Pollution Are Hurting Water Resources, EIU ViewsWire, 27 February 2001; Michael Ma, “Northern Cities Sinking as Water Table Falls,” South China Morning Post, 11 August 2001.
26. Cited in Lester R. Brown and Brian Halweil, “China’s Water Shortages Could Shake World Food Security,” World Watch, July/August 1998, pp. 11–12.
27. Water-to-grain conversion based on 1,000 tons of water for 1 ton of grain from FAO, Yield Response to Water (Rome: 1979), on world wheat prices from International Monetary Fund (IMF), International Financial Statistics (Washington, DC: various years), and on industrial water intensity in Mark W. Rosegrant, Claudia Ringler, and Roberta V. Gerpacio, “Water and Land Resources and Global Food Supply,” paper presented at the 23rd International Conference of Agricultural Economists on Food Security, Diversification, and Resource Management: Refocusing the Role of Agriculture?, Sacramento, CA, 10–16 August 1997; Wang Ying, “Rice Cropped for Water,” China Daily, 9 January 2002.
28. Ci Longjun, “Disasters of Strong Sandstorms Over Large Areas and the Spread of Land Desertification in China,” in Yang, Squires, and Lu, op. cit. note 8, p. 215; Lu Qi and Ju Hongbo, “Root Causes, Processes and Consequence Analaysis of Sandstorms in Northern China in 2000,” in ibid., p. 241.
Copyright © 2002 Earth Policy Institute