Like the rest of Europe, Switzerland has been smothered in heat with temperatures well above 30 degrees Celsius (86 Fahrenheit) for the past two months.

But the heatwave carried by winds from Africa has more devastating consequences in the mountains, shifting the freezing point to a much higher altitude and melting the ice that normally binds rockfaces together at the height of the climbing season.

On Thursday, the zero degree mark in the Alps stood at an altitude of 4,200 metres (13,860 feet), well above the more usual 3,000 or so metresfeet) in summer.

The sweltering temperatures have also highlighted the role of the Alps, like many mountain ranges with glaciers, as a barometer to assess the extent of climate change and the impact of global warming, according to experts.

"It's a really exceptional situation," Martin Funk, a glaciologist at Zurich's Federal Institute of Technology said.

Three weeks ago, 90 climbers were evacuated by helicopter from one of Switzerland's prized landmarks, the 4,478 metre high (14,777 feet) Matterhorn, following a landslide at 3,400 metres.

Wisps of steam could be seen emerging from the mountain under the beating sun and the Matterhorn was declared off-limits for several days while work was carried out to secure rockfaces.

A total of 55 people have been killed in mountain accidents in Switzerland so far this year, many because of rockfalls, compared to 27 or 28 for the same period in previous years, according to the Swiss ATS news agency.

But mountain rescue services believe that might be down to the fact that the hot weather has brought more people into the Alps and lulled them into a false sense of security.

Climatologist Martin Beniston, who works for the UN's Intergovernmental Panel on Climate Change (IPCC), warned last winter that one sign of accelerating climate change would be the melting of the permanent icecap on the Alps, permafrost.

While some degree of melting icecaps and glaciers during the summer months is normal, the swathes of flowing white ice which cover some high valleys are receding at a faster rate than usual.

"Most Alpine glaciers are in the phase of strong retreat at the moment and they have been for the last ten or 15 years," Beniston said, adding that they had been pushed back more than any time in the last 500 years.

Funk told the Swiss news agency ATS that the heatwave could bring about more unpredictable results, such as hidden pockets of water inside glaciers which could suddenly burst, causing water to crash down into valleys or triggering landslides.

Earlier this week, newly-formed lakes at the foot of a glacier in the south of the country, the Grubengletscher, were emptied as a precaution, while authorities were keeping a close watch on a growing lake on the Triftsgletscher in central Switzerland.

Climate experts monitoring the Alps warned that this summer's extremes may be the norm for the later half of this century.

Beniston and fellow scientists at the University of Fribourg forecast a 400 to 500 kilometre northwards shift in Europe's climate patterns, giving Switzerland a Mediterranean climate on a par with Tuscany.

"It's highly likely if you believe the IPCC projections of an acceleration of greenhouse gases (pollutants) in the future, and temperatures following," Beniston said.

"Vegetation is not going to follow quite as quickly. So it's going to be a rather unpleasant situation like today because the environment we live in is not geared to such drought and high temperatures," Beniston said.

Geraniums gracing Swiss chalets can always be swapped for exotic flowers, but for farmers used to milking cows and growing greens the consequences could be far reaching, according to models used by the Swiss environment ministry.

Cows are already suffering because of dried meadows, causing a milk shortage this summer, the Swiss milk producers' association said recently.

Up in the mountains, climate change will also hit the livelihoods of low to medium altitude winter resorts in 50 to 90 years time. If global warming accelerates there will simply not be enough snow to ski on, Swiss climatologists predict.

SPACE.WIRE