Alpine glacier retreat pushing Europe closer to water crisis

Ray Smith in the Guardian (UK) via IPS: Even though their ice is called 'eternal', many alpine glaciers' lives may come to an end within this century. For 150 years, most of them have been more or less constantly retreating, and since the eighties, their shrinkage has visibly increased. The Furka Pass in central Switzerland has long been awaiting its visitors with a special attraction. Just below the highest point of the pass, tourists may enter an ice grotto dug into the Rhone glacier to discover glacier life from the inside. Each year however, the grotto's entry can be found a few metres further downhill. Long-term measurements reveal that from 1879 to 2010, the Rhone glacier has lost 1266 metres of its original length.

The Swiss Alps are often called 'Europe's water tower'. Nearly 60 billion cubic metres of water are stored in its glaciers. Matthias Huss, glaciologist and senior lecturer at the Department of Geosciences at the University of Fribourg explains that glaciers fulfil a balancing function: "They release water exactly when we need it, while storing it in periods when we need it less."

In other words, glaciers store water during the cold and wet winter months. From May to September, snow and ice melt on the glacier surface and provide the water that is dearly needed during the hot and dry season. That same mechanism also balances year-to-year variations: in colder, wetter years glaciers accumulate water that is released in relatively hot and dry summers like in 2003.

The threat posed to alpine glaciers' essential contribution has long been recognised. However, a new study presented by Matthias Huss in the scientific journal 'Water Resources Research' found that the proportion of glacier water running down major European streams is larger than previously assumed.

"I have compared water runoff data from glaciers with actual runoff at gauges along the entire length of four major streams originating in the Swiss Alps," explains the glaciologist. His study is based on measurements along the Rhine, Rhone, Po and Danube rivers. The comparison allowed Huss to determine the relative share of glacier water running down those streams. "Consequently, I was able to quantify how much the runoff of those streams could decrease in case the glaciers' contributions are entirely lost," he says.

Matthias Huss of the University of Fribourg also stresses that the current picture is deceptive. "Due to climate change, we currently get more water from the glaciers than normally, as they're melting. At first glance it looks like there's no problem," he says. But Huss warns that soon the picture will change and the remaining glaciers won't be able to provide enough water during the summer months. Huss' glacier models are linked to specific climate scenarios. Diverging global warming estimates therefore affect prognoses regarding glacier shrinkage significantly...

The tongue of the Rhone Glacier in Switzerland, shot by Jamcib, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported