From China Watch (link):
In recognition of the grave perils of increasing desertification, the United Nations has declared 2006 the International Year of Deserts and Desertification and the theme of World Environment Day on June 5, 2006 is, “Don’t Desert Drylands!”. Deserts and other dryland ecosystems now cover a third of the Earth’s land surface, and worsening land degradation puts more than a billion people in over 100 countries at risk of poverty, political instability, and other related effects. In China, desertification threatens to uproot growing numbers of residents from their homes and livelihoods. In the country’s arid north, the Mongolian Desert is rapidly encroaching on Shenyang, an industrial city of more than 40 million people; today, the distance between city and desert has shrunk to only 48 kilometers, down from 100 kilometers in 2000.