Scientists have found climate change in the Alps, Africa and Asia is melting glaciers with serious effects for water supplies.
The findings were revealed at the annual conference of the Royal Geographical Society and the Institute of British Geographers, being held in London.
Dr Stephan Harrison, from Oxford University, told conference: "The recent heatwave in Europe has served to highlight once again the potentially devastating effects of climate change.
Central and southern Europe is experiencing one of the most prolonged droughts for decades. While many of the continent's rivers are at low levels, those draining from the Alps are being fed from rapidly melting glaciers."
Scientists at Newcastle University, von Humbold University in Germany and the Kazakh Academy of Sciences found the climate in the Tien Shan mountain region of Kazakhstan is warming and the 416 glaciers there are melting rapidly, losing nearly two kilometres of ice per year from 1955-2000.
It will affect the livelihoods of millions of people in central Asia as many of the rivers which supply the irrigation schemes are fed by glaciers and permafrost in the high mountains, according to Dr Harrison and his colleagues.
In such arid regions of central Asia much of the water used for economic development comes from summer melting of glaciers and permafrost, and these supplies are replenished during winter snowfalls.
With global warming, such supplies are under threat and the water supply problems have the potential to destabilise the political situation in the region since many of the rivers and glaciers cross different state boundaries.
The Tuyuksu glacier, 30 kilometres south of Almaty, the largest city in Kazakhstan, is one of the most closely studied glaciers in the world because Kazakh scientists have been examining it since early in the last century.
Dr Harrison and his colleagues have shown that the Tuyuksu glacier has receded nearly a kilometre since 1923. Researchers also examined the Himalayas and mountains in Switzerland, Uganda and New Zealand.