Disappearing glaciers

Vanishing glaciers around the world give us some of the starkest images of rising global temperatures.  

Glaciers develop in areas of high snow fall where low temperatures mean that snow accumulates faster than it melts. The snow changes to ice and slowly moves downhill. Scotland was shaped by glaciers in the last Ice Age, ending about 10,000 years ago. Glaciers cut deep valleys, carved corries and dumped huge amounts of debris when they melted. Both Edinburgh and Glasgow owe much of their shape to underlying glacial landforms.

The rate at which glaciers retreat has increased dramatically in the last decades and is in line with the known trends in global and local temperature. These changes have occurred on all continents.

Some scientists predict that ice melt from glaciers will be the major cause of sea-level rise in the 21st century. They estimate that the accelerated melting of glaciers and ice caps around the world will cause global sea levels to rise add between around 100 and 240 mm by 2100.

In a few places glaciers are actually increasing in size, for example in parts of Norway.  Since glacial advance or retreat is controlled by the balance between snowfall and melt, in these areas increased snowfall, consistent with climate change, is greater than the increased rate of melting.  

The melting of glaciers and ice fields in the Himalayas is of particular concern. The seasonal melting of this ice feeds the great rivers of India, South East Asia and China, including the Ganges, the Yangtze and the Mekong. These rivers provide half of the drinking water for 2.6 billion people, 40% of the world’s population.

Photo credit: (above) Paul Keller - (below)Global Warming Art

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