Sunday, March 22, 2020

Glaciers in the Caucasus have Declined in Size by 16 Percent Since 1986, International Team of Experts Says


Paul Goble

            Staunton, March 17 – Glaciers in the Caucasus have declined by 16 percent since 1986, which means they are retreating by almost one half of one percent a year, an extremely rapid melting that will have enormous consequences for the environment and peoples there, according to a team of Russian and international experts on geography and climate.

            Their results are reported in a new article, “Supra-Glacial Debris Cover Changes in the Greater Caucasus from 1986 to 2014,” The Cryosphere 14 (2020): 585–598 at the-cryosphere.net/14/585/2020/ that has been summarized in Russian at  iq.hse.ru/news/349870014.html. It warns that glacier retreat there is greater than in the Alps.

            Using satellite imagery, the scholars found that glacier cover in the Caucasus declined from 692 square kilometers in 1986 to 590 square kilometers in 2014. Part of the reason for this, they say, has been the impact of global warming. Temperatures in the mountainous part of the Caucasus increased by 0.5 to 0.7 degrees Celsius over this period.

            But another factor has also been at work: the glaciers are becoming ever dirtier as a result of dust brought in from far afield by the winds. The dirtier the glaciers become, the experts say, the more rapidly the glaciers melt. Consequently, as nothing has slowed this process, they will decline in size even if global warming were to slow.

            The decline in size of the glaciers of the Caucasus has attracted less attention than the collapse of glaciation in Central Asia because the peoples of the former are far less dependent on glacial melt for potable water than are those in the latter. But the melting is having an impact, sparking more avalanches and mudslides in the highland areas of the Caucasus.

            With time, however, the melting of the glaciers will more dramatically affect portions of this region because there won’t be enough water to support agriculture or even human habitation and so peoples who have long lived in one place will be forced to move out of the mountains into lowland valleys and change their way of life and even identities.

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