China's Dust Storms Raise Fears of Impending Catastrophe
by Reggie Royston
for National Geographic News
|June 1, 2001|
Earlier this year, an unusually large dust cloud that originated in
northwest China drifted across the continental United States and
lingered over Denver and other areas, at times obscuring views of the
It isn't the first time a giant dust cloud from east Asia has reached the United States. But concerned observers say the vast sweep and the density of this latest one suggests that northwest China's once-fruitful agricultural land is eroding at an alarming rate, becoming useless desert.
China has mounted various efforts to halt the increasing desertification, which is caused by overuse of the land for farming and grazing. Nonetheless, as much as 900 square miles (2,300 square kilometers) of farmland in northern Chinaan area more than twice the size of Hong Kongis blown away by the wind each year, according to a Chinese scientist quoted in a New York Times article last year.
"If they're losing that much, then there is several times that area in various stages of deterioration. Losing it and abandoning it are sort of the final stage before it becomes desert," said Lester Brown, president of the Earth Policy Institute in Washington, D.C., which recently released an environmental alert on the problem.
East-moving winds often carry soil away from China's northwest, where overplowing and overgrazing, coupled with periods of drought, has led to massive deterioration of the country's agricultural resources.
Huge dust plumes regularly travel hundreds of miles to Beijing and other cities in northeastern China. As they move over urban centers they pick up particles from industrial pollution.
The resulting dust clouds are often so thick they obscure the sun, reduce visibility, slow traffic, and close airports. Residents caulk windows with old rags to keep out the dust, and municipal crews have to clean public structures repeatedly during the dust-storm season.
The dust clouds are also a problem for China's neighbors, and North Korea, South Korea, and Japan have registered official complaints. Responding to pressure from their citizens, legislators from Japan and South Korea are organizing a tri-national committee with Chinese lawmakers to devise a strategy to combat the dust.
On March 10, 2001, The People's Daily reported that the season's first dust stormone of the earliest on recordhad hit Beijing. The recent dust storms and those of last year were said to be among the worst in memory.
The growing severity of the dust clouds has raised world concern.
"Over the last few years, there has been a growing awareness that air pollution from China is affecting us," said Russ Schnell, an official at the U.S. National Oceanic and Atmospheric Administration, which tracked the recent dust clouds.
"Pollution is a global problem," he added. "Nature has sent us 'a perfect storm' to reinforce the fact that we are all downwind of someone else's pollution."
Uncontrolled Land Use
Ironically, the rapid deterioration of China's cropland has resulted in part from programs aimed at increasing agricultural output. Decades of reforms have included measures that removed limits on the amount of land that farmers could cultivate and the size of herds and flocks they could maintain. As a result, the demand for land has soared.
Another factor contributing to the problem is a 1994 policy requiring that any cropland used for construction be offset by setting aside land elsewhere for agriculture.
Fast-growing coastal provinces, such as Guangdong, Shandong, Zhejiang, and Jiangsu, are losing much cropland to urban expansion. Agricultural and pastoral provinces in the northwest, such as Nei Mongolia, Gansu, Qinghai, Ningxia, and Xinjiang, initially garnered an economic windfall from the policy, but are increasingly faced with plowing ever more marginal land.
Now accelerating wind erosion of soil and the resulting land abandonment are forcing people to migrate eastward, not unlike the U.S. westward migration from the southern Great Plains to California during the Dust Bowl years.
Adding to the direct damage to soil, the northern half of China is becoming drier and sources of natural irrigation more scarce. Temperatures in the region have been hotter than average in the past 10 years, and aquifers are being depleted by overpumping.
U.S. satellites, which have monitored land use in China for three decades, show that thousands of lakes in the north have disappeared. And rapid industrial development has reduced forests and other vegetation that once provided moisture to the region.
In some areas the land has been rendered so useless that farmers have abandoned their homes and fields, which are now covered with wind-blown sand dunes. Where farming is still practiced, some reports indicate that typical yields of crops such as potato, rice, and corn have shrunk dramatically, making harvests no longer profitable.
"The big risk is that it's going to push a lot of people into cities in a major migration," said Brown.
The Chinese government has been pursuing varied approaches to make the now highly arid land productive again. One strategy is planting trees and tracts of grass in "checkerboard" patterns, which has increased vegetation coverage in some areas and reduced the buildup of sand dunes.
During the late 1970s and early '80s, a system of agricultural "shelterbelts" was implemented by reforesting large tracts of land to anchor and irrigate loose soil and help stem the flow of dust storms across China.
Government reports indicate that some progress is being made in reversing the massive loss of land. Among the successful efforts cited, the buildup of sand dunes in some provinces has been reduced by as much as 64 percent, and total forest cover nationwide increased by 14 percent in 1995 as a result of intensive planting.
Yet some people are concerned that the ever more intensive cultivation of land in the north over the past decade has outpaced what progress has been made.
"If China cannot quickly arrest the trends of deterioration, the growth of the dust bowl could acquire an irreversible momentum," Brown warned. "What is at stake is not just China's soil, but its future."
Studies by Chinese scientists and the World Bank have concluded that China has lost U.S. $2 billion to $3 billion a year over the past decade from the effects of lost land and productivity, threatening the livelihood of at least 170 million people.
"Desertification has become a bottleneck for the social and economic development and the improvement of people's living standard in some areas," Jiang Chunyun, vice premier of China's State Council, declared at a 1997 United Nations conference on desertification.
"[In] other areas most severely affected by desertification," he added, "the problem of food and shelter for local residents remains unsolved."
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