| Summary: | Trend analyses for the period from 1879 to 2000 at 16 climate stations located in and around Northern Tien Shan show an air temperature increase, which has become pronounced since the 1950s. This can be attributed mainly to a temperature rise in autumn and winter. However, the increase is less pronounced in the mountainous areas. For precipitation, there was a small increase on average, but no clear trend. Geothermal observations during 1974 – 1977 and 1990 – 2006 indicate that the permafrost has also been warming in the Tien Shan Mountains during the last 30 years. On average, the decrease was more than 32 ± 8 % in glacier extent and about 37.5 ± 9 % of glacier volume between 1955 and 1999 in the investigated six valleys. In 1999, active rockglaciers covered ca. 13 % of the glaciated area and contained roughly estimated an ice volume of about 3 – 4 % of the total glacier ice volume. The ice content of the whole permafrost area is probably much higher. Under continued warming, it can be assumed that glaciers will retreat and permafrost will degrade in Central Asia, the melting ground ice could increase future water supply, and the melt waters from permafrost could become an increasingly important source of fresh water in this region in the near future
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