China's Dust Storms Raise Fears of Impending Catastrophe

In 2001 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 Rocky Mountains.

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 suggest 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 2 300 square kilometres of farmland in northern China – an area more than twice the size of Hong Kong – is blown away by the wind each year.

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 that 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 growing severity of the dust clouds has raised world concern. The dust clouds are also a problem for China's neighbors – 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.

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. Fast-growing coastal provinces are also losing much cropland to urban expansion. The big risk is that it is going to push a lot of people into cities in a major migration.

Now accelerating wind erosion of soil and the resulting land abandonment are forcing people to migrate eastward. 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.

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.

Scientists say that desertification has become a bottleneck for the social and economic development and the improvement of people's living standard in some areas of China.

Reggie Royston. National Geographic New. 2001