Melting glaciers

Swiss glaciologist Samuel Nussbaumer from the World Glacier Monitoring Service (WGMS) in Zurich analyzes the development of glaciers around the world. Nussbaumer told Deutsche Welle the future of glaciers is seriously under threat.

DW: Mr Nussbaumer, you and your colleagues monitor glaciers all around the world. What can you tell us about the glacier in the Himalayas?

Samuel Nussbaumer: In contrast to the Alps, in the Himalayas, there were far fewer field measurements documented over a period of time. This poses certain problems, because there are still many uncertainties. The glaciers have significantly receded in the Karakoram region, where the mass balance is being observed.

What sort of role does climate change play in glacier retraction?

Glaciers are affected by the climate - the temperature, precipitation and the sun's rays. When the earth's temperatures rise, the glaciers are more likely to melt and retract. In this respect, one can say that the decline of glaciers in the Himalayas is a consequence of climate change. But the question arises of just how much of this caused by humans. There are natural climate variations, but they are clearly enhanced by human activities. Climate models show the impact that climate change has made since the 1950s.

If we look at the Alps, do you think later generations will get to see the glaciers of Switzerland, Austria or Bavaria?

It's estimated that by 2050, about only a quarter of today's glacier surface will still exist. It's also estimated that by 2100, areas below 3,500 meters will no longer have any snow during the summer.This means there won't be any glaciers below this altitude either, as snow is necessary for the glaciers to survive. Glaciers, however, react with a certain amount of delay. For example, the big Aletsch glacier, which is the largest glacier in the Alps, will take 50 or more years to adapt. Therefore, in 100 years time, some parts of the Aletsch Glacier will most likely still exist.

What are the consequences of the retraction of mountain glaciers?

During the winter, when the snow falls and the ice forms, the glaciers collect and store precipitation, which releases water in summer periods.They also a channel runoff water from winter to summer. Glacial loss increases the risk of flooding as the water runs off too quickly. There is also the possibility of water shortages in the summer.

As the glaciers retract, they also leave behind a lot of debris. And this can contribute to mudslides in the event of storms. The mud form lakes which are unstable and can suddenly collapse. This is also a big problem in the Himalayas.

Is this is growing problem?

Yes, a lake has formed around the lower Grindelwald glacier. To prevent the risk of a mudslide, you have dig a tunnel through the rock so that the water can drain. In Europe, we can resolve this problem with relative ease, but in the Himalayas the funds aren't readily available.

This seems to deal solely with the symptoms without directly addressing the cause.

This is precisely the problem. Even if we dramatically reduce our CO2 emissions today, we will still see warming in the next 50 years.

Would it be fair to say that there's not much we can do to prevent the decline of glaciers around the world?

We have the perspective of nostalgic glaciologists. Only 150 years ago, there was a plenty of ice and now we only sees only meager amounts. And in the future there will be perhaps no more glaciers. This is an alarming development.