Melting glaciers: What you need to know

February 15, 2012 | 4:13 pm | , Science and Solutions Director

© 2010 Flickr/Glenna Barlow CC BY 2.0

If you haven’t already, take a look at this eye-opening blog post about an expedition into the mountains of Nepal. For people in the region, climate change isn’t just an abstract worry; they live with a real and everyday concern about dangerous flash floods that can result from melting glaciers.

Sadly, this is a danger that won’t go away soon. Glaciers all over the world are shrinking. This sustained ice loss is both a natural indicator that the world is warming and a warning that local communities are at risk. For people inland, melting glaciers can mean flash floods, landslides and reduced drinking water. For people on the coast, melting glaciers mean rising seas.

© 2008 Flickr /wildxplorer CC BY 2.0

We’re learning more about glacial retreat all the time. Recently, a new study was released that received a great deal of media attention. It found that mountain glaciers and polar ice sheets lost more than 530 gigatons of ice per year from 2003 to 2010, raising average global sea levels more than 1 centimeter. This study is consistent with other estimates of the contribution of land ice to sea level rise. In other words, not that surprising.

What is surprising from a scientific perspective – and has some media outlets in a tizzy – is that ice cover in the Himalayas may be shrinking more slowly than previously thought.

The high mountains of Asia, including the Himalayas, Tian Shan and other mountain ranges, have been notoriously difficult to study. Unlike the well-known glaciers of Alaska or the Alps, many of Asia’s high-mountain glaciers are difficult to access, and the region is plagued by border conflicts and wars. Furthermore, ice trends in the region aren’t exactly simple. As one scientist recently put it, “each glacier has its own individual behavior.” Glaciers may be retreating in some areas but not others, making it difficult to establish an average rate of retreat for the region.

If anything, a lower rate of ice loss in the Himalayas is good news. The glaciers help provide millions of people in Asia with drinking and irrigation water, and low-lying regions like coastal Louisiana need all the time they can get to prepare for sea level rise. But as Jonathan Bamber, head of the Bristol Glaciology Centre in the UK points out, the new study “doesn’t change our view of the risks and threats from climate change.” As the Earth continues to warm, even the formidable glaciers of the Himalayas can’t hang on forever.