"It is estimated that 50 to 90 percent of current Alpine glaciers will have disappeared by the end of the 21st Century

Professor Martin Beniston

Temperatures have already risen about one degree in the last 10 years.

This has caused the snow line to recede up the side of most mountains by an average of 150 metres.

In the European Alps, it could move from 1200 metres to 1800 metres within 15 years.

Glaciers melting

Professor Martin Beniston, from Fribourg University in Switzerland, says the future is very worrying.

"Global warming will reduce the snow pack area and glaciers will experience accelerated melting", he says.

"It is estimated that 50 to 90 percent of current Alpine glaciers will have disappeared by the end of the 21st Century".

Changes in the snowpack have been reported in Zermatt

Detailed climate research is now being carried out at several areas, including the Swiss resort of Zermatt.

Zermatt is one of the highest resorts in the Alps, with skiing available at over 3000 metres.

But even here things are changing.

"We see the glaciers going back and the crevasses getting bigger", says local mountain guide Mathias Hediger.

"It really saddens me to see the mountains kind of falling apart".

Low level skiing resorts have the most to lose as they could end up with no snow at all.

We see the glaciers going back and the crevasses getting bigger

Swiss mountain guide

Many are investing heavily in snow-making machines but their spending could be in vein.

Snow cannons only work if the air temperature is below freezing in the first place.

In some resorts, skiing could disappear all together.

"Many people say global warming is not happening. Well it is", says Peter Hardy, co-editor of 'The Good Skiing and Snowboarding Guide'.

Popular resorts like Val D'Isere could suffer

"Some of the low level ski resorts will simply be wiped out. At Christmas this year I would not dream of going to a resort below 1800 metres".

But according to an expert at England's Reading University, it might not all be bad news.

Dr David Stephenson, head of climate research at the university, is studying long-term climate changes in the Alps.

"There will be greater snow falls at in the higher resorts," he said.

"So although fewer ski resorts will have snow, those that do could well have more of it."

For the higher resorts like Val Thorens, Zermatt and Tignes, the future could be bright.

Weather trends

Latest weather trends also show the skiing and boarding season is extending into spring, as more snow tends to fall at the high resorts late in the season.

Skiers might find conditions better at the end of the season

So although many of the tour operators close down after Easter, there is often great skiing well beyond that.

The highest resort in The Alps is Val Thorens in France.

At the beginning of May this year, when most skiers had gone home, a select few were enjoying excellent conditions.

Fiona Sweetman from the Ski Club of Great Britain took advantage of the uncrowded pistes and great snow.

"The conditions here are fantastic," she said. "We have blue sky, fresh snow and no lift queues. I really don't know why people ski in January in the cold when they could be enjoying this".

Other skiers and boarders could learn from this and make their trips later in the year.

If current climate changes continue and the scientists are right, then winter skiing at low level resorts could become a thing of the past.