The Mu'us Desert in Inner Mongolia has advanced 200 km to the south in 1600 years. According to Professor LI Chengsen of the Beijing Institute of Botany of the Chinese Academy of Sciences, who studies the ruins of the ancient city of Tongwan in the province of Shaanxi, witness to desertification, the current average rate of desertification is 126 m per year.

Former capital of the Huns of ancient China, built between 413 and 418, the city of Tongwan is today located in the heart of the Mu'us desert. Studies of the flora reveal that it was once surrounded by forests of Platycladus orientalis, lakes and rivers, and that it enjoyed a temperate climate. The mean annual temperature was between 7,8 and 9,3ºC with mean annual precipitation between 403,4 and 555 mm. Currently, the average temperature is between 0,2 and 0,7ºC and precipitations are between 60 and 100 mm. The forests retreated 200 km to the south, as far as Yan'an.

Sources: Academy of Sciences of China,
http://english.cas.ac.cn/eng2003/news/detailnewsb.asp?InfoNo=25287