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Chapter 3. Eroding Soils and Shrinking Cropland: Advancing Deserts
Desertification, the process of converting productive land to wasteland through overuse and mismanagement, is unfortunately all too common. Anything that removes protective grass or trees leaves the land vulnerable to wind and to water erosion and the loss of topsoil.
In the early stages of desertification, the finer particles of soil are removed by the wind, creating dust storms. Once the fine particles are removed, then
the coarser particles—the sand—are also carried by the wind. Sand storms are capable of destroying vegetation and of disrupting transportation by blocking highways and railroads with drifting sand. A scientific paper analyzing a particularly severe dust and sand storm in May 1993 in Gansu Province in China's northwest reported that it reduced visibility to zero and described the daytime sky as "dark as a winter night." The storm killed 49 people, destroyed 170,000 hectares (450,000 acres) of standing crops, damaged 40,000 trees, and killed 6,700 cattle and sheep. Forty-two trains were cancelled, delayed, or simply parked to wait until the storm passed and the tracks were cleared of drifting sand.15
Large-scale desertification is concentrated in Asia and Africa—two regions that together contain nearly 4 billion of the world's 6.2 billion people. The demands of growing human and livestock populations are simply exceeding the land's carrying capacity.16
On the northern edge of the Sahara, Algeria is facing the desertification of its cropland. In December 2000, agriculture ministry officials announced a four-year plan to halt the advancing desert by converting the southernmost 20 percent of Algeria's grainland into fruit and olive orchards, vineyards, and other permanent crops. The government hopes that this barrier of vegetation will halt the northward movement of the Sahara and save the country's fertile northern region.17
To the south, Nigeria-Africa's most populous country—is fighting a losing battle with the advancing desert. Each year, it loses 351,000 hectares (877,000 acres) of land to desertification. Affecting each of the 10 northern states, desertification has emerged as Nigeria's leading environmental problem.18
In East Africa, Kenya is being squeezed by spreading deserts, and desertification affects up to a third of the country's 32 million people. As elsewhere, the unholy triumvirate of overgrazing, overplowing, and overcutting of trees are all contributing to the loss of productive land.19
Iran is also losing its battle with the desert. Mohammad Jarian, who heads Iran's Anti-Desertification Organization, reported in 2002 that sand storms had buried 124 villages in the southeastern province of Sistan-Baluchistan, leading to their abandonment. Drifting sands had covered grazing areas, starving livestock and depriving villagers of their livelihood.20
Neighboring Afghanistan is faced with a similar situation. The Registan Desert is migrating westward, encroaching on agricultural areas. A U.N. Environment Programme (UNEP) team reports that "up to 100 villages have been submerged by windblown dust and sand." In the country's northwest, sand dunes are moving onto agricultural land in the upper reaches of the Amu Darya basin, their path cleared by the loss of stabilizing vegetation from firewood gathering and overgrazing. The UNEP team observed sand dunes 15 meters high blocking roads, forcing residents to establish new routes.21
China is being affected more by desertification than any other major country. For the outside world, the evidence of this is often seen in the dust storms in late winter and early spring, as described in Chapter 1. These storms, which regularly reach the Korean peninsula and Japan, sometimes even cross the Pacific, depositing dust in the western United States.22
Overgrazing is the principal culprit. 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 soared. The 106 million cattle and 298 million sheep and goats that now range across the land are simply denuding the western and northern part of the country, a vast grazing commons.23
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 as grassland, but that a simple visual survey indicates that a third of the terrain appears to be desert. The report describes the livestock population in the prefecture climbing from 2 million as recently as 1977 to 18 million in 2000. A Chinese scientist doing grassland research in the prefecture says that if recent desertification trends continue, Xilingol will be uninhabitable in 15 years.24
A recent U.S. Embassy report entitled "Desert Mergers and Acquisitions" says satellite monitoring shows two deserts in north-central China expanding and merging to form a single, larger desert overlapping Inner Mongolia and Gansu provinces. To the west in Xinjiang Province, two even larger deserts—the Taklimakan and Kumtag—are also heading for a merger. Highways in this area are regularly inundated by sand dunes.25
The overgrazing, overplowing, and overcutting that are driving the desertification process are intensifying as the growth in human and livestock numbers continues. Stopping the desertification process from claiming ever more productive land may now rest on stopping the growth in human numbers and in the livestock on which they depend.
15. Yang Youlin, "Dust Sandstorms: Inevitable Consequences of Desertification—A Case Study of Desertification Disasters in the Hexi Corridor, NW China," in Youlin, Squires, and Qi, op. cit. note 7, p. 228.
16. United Nations, World Population Prospects: The 2002 Revision (New York: February 2003).
17. "Algeria to Convert Large Cereal Land to Tree Planting," Reuters, 8 December 2000.
18. Government of Nigeria, Combating Desertification and Mitigating the Effects of Drought in Nigeria, National Report on the Implementation of the United Nations Convention to Combat Desertification (Nigeria: November 1999), p. 6.
19. United Nations, op. cit. note 16; Republic of Kenya Ministry of Environment and Natural Resources, National Action Programme: A Framework for Combating Desertification in Kenya in the Context of the United Nations Convention to Combat Desertification (Nairobi: February 2002), pp. 12-14.
20. Iranian News Agency, "Official Warns of Impending Desertification Catastrophe in Southeast Iran," BBC International Reports, 29 September 2002.
21. U.N. Environment Programme, Afghanistan: Post-Conflict Environmental Assessment (Geneva: 2003), p. 52.
22. Lester R. Brown, "Dust Bowl Threatening China's Future," in Lester R. Brown, Janet Larsen, and Bernie Fischlowitz-Roberts, The Earth Policy Reader (New York: W.W. Norton & Company, 2002), pp. 200-04.
23. Economic reforms from Erik Eckholm, "Chinese Farmers See a New Desert Erode Their Way of Life," New York Times, 30 July 2000; livestock population from FAO, FAOSTAT Statistics Database, at apps.fao.org, livestock data updated 9 January 2003.
24. U.S. Embassy, Grapes of Wrath in Inner Mongolia (Beijing: May 2001).
25. U.S. Embassy, "Desert Mergers and Acquisitions," Beijing Environment, Science, and Technology Update (Beijing: 19 July 2002), p. 2.
Copyright © 2003 Earth Policy Institute