FACTBOX - Impacts of glacier retreat on hydropower

REUTERS - Retreating glaciers from the Alps to the Andes are likely to disrupt hydropower generation in coming decades.

Following are details of glaciers and the wider impacts of climate change on hydropower, the most widely used form of renewable energy:

* WORLDWIDE

More than a billion people live in river basins fed by glacier or snow-melt. Climate change will lead to a retreat of glaciers and cause wider disruptions to rain and snowfall patterns from tropical Monsoons to Arctic snowfall.

* ASIA

Himalayan glaciers may shrink to 100,000 square km (40,000 sq miles) by the 2030s from 500,000 sq km if current warming rates continue. That would increase river flows in some river systems for two to three decades, followed by decreasing flows.

Water supplies will be hit in areas fed by melt water from the Hindu Kush and Himalayas, on which hundreds of millions of people in China, Pakistan and India depend.

* EUROPE

Small glaciers will disappear and larger glaciers will shrink by between 30 and 70 percent by 2050.