By Ben Harder
From St. Louis, Mo., at a meeting of the American Association for the Advancement of Science
Carried forward by winds and sandstorms, the dunes of northern China are expanding at an unprecedented rate, Chinese researchers say. Human activities are primarily responsible for desertification of the arid and semiarid grasslands of the area, they conclude.
The average rate of desert expansion in the region was 3,600 square kilometers per year during the 1990s, compared with 1,560 km2 annually during the late 1950s, says Tao Wang of the Chinese Academy of Sciences in Lanzhou.