Glaciers in Central Asia experience substantial losses in glacier mass and area. Along the Tien Shan, Central Asia's largest mountain range, glaciers have lost 27% of their mass and 18% of their area during the last 50 years. An international research team led by the GFZ German Research Centre for Geosciences and including the institute of the French Centre National de la Recherche Scientifique (CNRS) at Rennes University in particular, estimated that almost 3000 square kilometres of glaciers and an average of 5.4 gigatons of ice per year have been lost since the 1960s. In the current online issue of Nature Geoscience, the authors estimate that about half of Tien Shan's glacier volume could be depleted by the 2050s. Glaciers play an important role in the water cycle of Central Asia. Snow and glacier melt from the Tien Shan is essential for the water supply of Kazakhstan, Kyrgyzstan, Uzbekistan, and parts of China. "Despite this importance, only little was known about how glaciers in this region changed over the last century" the principal investigator Daniel Farinotti explains. Most of the direct monitoring programs, that were shut down with the collapse of the Soviet Union, are resumed only today, and modern observation techniques often cover a limited time span only.

GFZ-researcher Farinotti and colleagues now present a reconstruction of the glacier evolution in the Tien Shan. "We combined various methods based on satellite gravimetry, laser altimetry and glaciological modelling" Farinotti says. "This way, we were able to reconstruct the evolution of every single glacier. Currently, the Tien Shan is losing ice at a pace that is roughly twice the annual water consumption of entire Germany."