By James Cove
BBC News, The Swiss Alps
The search for fresh snow is leading skiers higher up the mountains
Standing on the Aletsch glacier above the Swiss resort of Grindelwald it's hard to believe that winter is supposed to be over.
There's deep snow under foot, a glorious blue sky overhead and below us a 1000-metre descent. It may have been the warmest April since records began, but where I'm standing it's April and it's still winter.
But then I'm at an altitude of 3,900 metres and have walked to the top of the mountain, as at this height there are no ski lifts. I'm ski touring, which is becoming one of the fastest growing sports in the Alps.
Climate change is forcing skiers to go ever higher to find snow and April/May is the height of the ski touring season. Ski tourers do not use lifts but rather walk uphill to find fresh snow.
Despite all the talk of poor snow this winter, many of the high areas actually received more than last year.
Skiers vote with feet
Overall, though, it's been a poor season as it was too warm. Some resorts had to close in January, normally the coldest part of the winter, and others had to shut lifts early because of a lack of snow.
Retreating snow and ice are evidence of climate change
With strict environmental controls about where new lifts and ski stations can be built, some skiers are voting with their feet and simply walking uphill.
The Aletsch glacier is in the Bernese Oberland, and at 22 kilometres (14 miles) it is the longest glacier in Switzerland.
The whole area has been declared a Unesco world heritage site for its outstanding beauty. On clear days the views extend from the Vosges mountain range in France to the Black Forest in Germany. It is one of the most stunning places I have visited in the Alps.
"Many skiers want to find fresh snow and sometimes the only way to do it is to walk uphill," says Owain Jones, a mountain guide with British company Mountain Tracks, that specialises in ski tours.
"It requires a degree of fitness and determination but is within the capabilities of most good intermediate skiers."
The top of Europe
To reach the ski touring area in the Bernese Oberland you are helped by the Jungfraujock mountain railway that runs through The Eiger. It takes you to 3,450 metres and is the highest railway station in Europe. It took 16 years to build and was opened in 1912.
Half way up is a platform that gives spectacular views and has been the start point for many of the rescue attempts when climbers get into difficulty on the treacherous north face of The Eiger.
Once at the top skiers put skins on the bottom of their skis, so they do not slide backwards, and then walk up hill.
There are numerous mountain huts in the area to stay at. Some are very basic while others border on the luxurious with private rooms and fully stocked kitchens and bars.
The area is one of the most stunning places on earth with soaring peaks and spectacular ice falls. However the growing numbers going to the area have brought some environmental worries.
The huts need supplies and so there are numerous helicopter trips that cause environmental pollution. Most huts have their own generators that run on diesel.
Although the vast majority of people take their litter away I saw empty bottles, cigarette ends and paper left on the glaciers.
"It is very important that these high altitude areas remain unspoilt by ski tourers, so they must respect the environment," says Betony Garner from The Ski Club of Great Britain.
"They should take all their litter home with them and follow the rules."
The area also provides dramatic evidence of climate change as one can see where the glaciers have retreated. Many of the mountain huts were built by the side of the glacier, but now several decades on these huts are often hundreds of yards from the edge of the glacier.
Safety is paramount
Ski touring can be dangerous as the risk of avalanches is ever-present and rescue is a long way away if things go wrong. Much of it is done on glaciers so there is constant danger of falling into a crevasse.
Also altitude sickness and the cold can cause problems. Unless you are experienced it is essential to hire a qualified mountain guide to take you safely through the area.
With no sign of climate change slowing down, ski touring will undoubtedly continue to climb in popularity. It will of course never replace ordinary skiing as walking up hill for long periods of time is most certainly not everyone's idea of fun.
However hundreds of people are in the Bernese Oberland and it's estimated that there are many thousands ski touring across The Alps at the moment.