Question

Some mountain glaciers are advancing (e.g. those of the Karakoram range in the Greater Himalaya). How can mountain glaciers advance while the global mean temperature is increasing?

Answer 1

Glaciers can advance irrespective of the rise of global mean temperatures. The huge weight of a layer of thick ice, or considering the enormous force of gravity on the mass of ice, causes glaciers to flow very slowly. Often, it happens that a glacier slides over a thin layer of water at the base of the glacier. This water is a consequence of melt of glacier formed from pressure of the overlying ice, or from water which can work through cracks in glacier to the base of it.

But increasing temperatures of the Earth plays its part in increasing the rate of advancement of glaciers, by accelerating the rate of formation of melt water at the base of the glaciers (thawing), since higher temperatures would mean that ice would melt more quicker than what was before. This phenomena, along with the already existing processes of melting of ice as described above, lets the glacier to move at an even faster rate during summers and this rate of advancement is gradually increasing with increased rate of warming of the Earth.