Tien Shan Mountains Credit: Wikipedia
Scientists have analyzed climate changes and glaciation in the Tien Shan Mountains (Central Asia), and explained their consequences.
After the fall of the Soviet Union twenty years ago, water distribution in Central Asia became a source of conflict. In areas where summer precipitation is low, glaciers play an important role when considering the quantity of available water. The Tien Shan region is a prime example; mountain glaciers in this region contribute significantly to the fresh water supply in the arid zones of Kyrgyzstan, Kazakhstan, Uzbekistan, Turkmenistan, and Northwestern China. Like Switzerland, Kyrgyzstan serves as a water tower for its neighboring countries.
While the impact of climate change on glaciation and water flow in the Tien Shan Mountains has already been the subject of studies, a consistent and local perspective of collected data has never before been presented. The results of this research, led by the l’UNIGE, show that the retreat of glaciers is more pronounced in peripheral areas, where summers are dry and melting ice and snow are key sources of water.
Glaciers are losing their surface every year
The glaciers in the Tien Shan Mountains cover a surface of over 15,000 square kilometers, equivalent to one third of the surface area of Switzerland. In recent decades, these glaciers have lost between 0.1% and 0.8% of their surface per year; a decrease comparable to that of alpine glaciers. The largest retreat was observed on the periphery of the Tien Shan Mountains, near the major cities of Almaty, Bishkek, Tashkent and Ürümqi. “In the summer, glaciers are the only source of fresh water for irrigation and household consumption in these regions,” said Annina Sorg, first author of the study and researcher at the ISE (UNIGE) and at the Institute of Geology of Bern University. “The intensification of glacial melting strongly affects the quantity and seasonal distribution of water. Initially, the retreat of glaciers is going to increase the available water resources, but if precipitation doesn’t compensate for the losses related to glacial retreat, the reduction of glacier volume will eventually reduce the amount of available water.”