Monday, September 24, 2007

The Great Depressing (A Topsoil Story)

This was our past.

Lester R. Brown, Eco-Economy: Building an Economy for the Earth (W.W. Norton & Co., NY: 2001)

The United States, the world's breadbasket, has undergone two periods of extensive overplowing, each of which led to heavy losses of topsoil. The first occurred in the early 1930s when a severe multiyear drought led to extensive wind erosion in the southern Great Plains. The resulting environmental devastation not only gave the era its name, the Dust Bowl, but it triggered one of the largest internal migrations in U.S. history as droves of people left the southern Great Plains and headed west for California.

This is China's present.

In the majority of developing countries, the growing demand for food has forced agriculture onto marginal lands. In China, for instance, a doubling of population since 1950 combined with record rises in income since 1980 have nearly tripled the demand for grain.

China's loss of cropland to the construction of factories, roads, and expanding cities, particularly in the prosperous coastal provinces, led to mounting concern in Beijing about the country's shrinking cropland area. The result was an attempt to offset these losses by plowing more land in the semiarid northwest. But the newly plowed land, much less productive, was highly vulnerable to wind erosion.

As described at the beginning of this chapter, in recent years dust storms in China have become more frequent and more intense, often covering cities in the northeast with layers of dust. In May 2000, the China Daily reported, "Disastrous sand storms that hit several major cities recently in North China have alarmed the nation about the devastating consequences of the development strategy that turned a blind eye on the environment." The desertification now under way in northwest China aroused public concern as "dust-laden blasts began to bury villages, blow into cities, and suffocate residents."

These new reports, coupled with scientific studies, indicate that a dust bowl is forming in northern China. The April 2001 dust storm mentioned earlier was one of the largest ever recorded. U.S. scientists in Colorado measured the dust in this storm above them in Boulder at altitudes up to 10,700 meters (35,000 feet). China is losing millions of tons of topsoil, a depletion of its natural capital that it can ill afford.

The Chinese Dust Bowl
To date, Chinese farmers and herders have transformed about 400,000 square kilometres of cropland and verdant prairie into new deserts. The shepherds have overgrazed the steppes, allowing their sheep and goats to chew the grass all the way down to its roots. The farmers, for their part, have over-exploited the arable land by opening fragile grasslands to cultivation and over-pumping rivers and aquifers in the oases bordering the ancient deserts. The area of desert thus created is equivalent to more than half the farmland in Canada.

China's eternal empire
In terms of conventionally measured growth, China is a miracle. In terms of pollution, however, it is a catastrophe so bad that the latest edition of Foreign Affairs calls it "The Great Leap Backward." Coal-burning power stations spew forth sulfur dioxide and particulates. Acid rain and soil exhaustion are inexorably enlarging the Gobi Desert. Dust storms and brown smog clouds are becoming commonplace. So are pollution-related cancers.

See Also: Earth Policy Institute

This post inspired by kwark's topsoil comment.

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