Cryospheric change in China

Abstract

This paper provides an overview of the current status of the cryosphere in China and its changes. Up-to-date statistics of the cryosphere in China are summarized based on the latest available data. There are 46,377 glaciers in China, covering an area of 59,425 km 2. The glacier ice reserve is estimated to be about 5600 km 3 and the annual glacier runoff is about 61.6 × 10 9 m 3. The continuous snow cover extent (> 60 days) in China is about 3.4 × 10 6 km 2 and the maximum water equivalent is 95.9 × 10 9 m 3 yr − 1 . The permafrost area in China is about 1.72 × 10 6 km 2. The total ground ice reserve on the Qinghai–Tibetan Plateau is estimated to be about 10,923 km 3. Recent investigations indicated that glacier areas in China have shrunk about 2–10% over the past 45 yr. Total glacier area has receded by about 5.5%. Snow mass has increased slightly. Permafrost is clearly degrading, as indicated by shrinking areas of permafrost, increasing depth of the active layer, rising of lower limit of permafrost, and thinning of the seasonal frost depth. Some models predict that glacier area shrinkage could be as high as 26.7% in 2050, with glacier runoff increasing until its maximum in about 2030. Although snow mass shows an increasing trend in western China, in eastern China the trend is toward decreasing snow mass, with increasing interannual fluctuations. Permafrost degradation is likely to continue, with one-third to one-half of the permafrost on the Qinghai–Tibetan Plateau anticipated to degrade by 2100. Most of the high-temperature permafrost will disappear by then. The permafrost in northeastern China will retreat further northward.