Chamonix, France: Skiing the remote and beautiful Vallee Blanche off piste

In this game, it pays to be flexible. Not just so you can ably ski the terrain and avoid its obstacles, but also so you don't crick your neck at the cable car's bottom station looking way, way up to the destination; nor strain your back emerging from the top station, bending through the ice cave, lest the skis strapped to your pack hit the roof and lock you in place.

We'd arrived at the Aiguille du Midi after a 20-minute cable car ride, struggling a little for breath at 3482 metres in altitude and 2800 metres above Chamonix, rooftops glistening in the valley below. It's a needle of a peak with an elaborate cable car station somehow bolted to its side and drilled into its interior, complete with cafe, gallery and views to the surrounding peaks.

This is the last lifted stop for alpinists with their sights set on the majestic Mont Blanc, at 4808 metres. Our sights are set elsewhere – to ski the beautiful Vallee Blanche, an easy enough run once you get to it, but getting to it is quite "technical", as they say.

Our guide, Julia Virat, had taken us slowly through the first steps. Roped together and crampons fitted, we'd then walked down the arete, a ribbon of a ridge that had us stepping with great care, averting eyes from the view down the plunging slope all the way back to town.

The walk to get to the skiing might have been tricky, but beyond the head of the glacier, the pitch of our route down the Vallee Blanche wasn't much greater than a challenging intermediate ski run. It isn't without risk though. "The problem isn't the crevasses you can see," Virat says, "it's the ones that have a thin cover of snow that you can't see." She has our full attention. "Follow my tracks but keep about 20 metres distant and when we stop, keep about five metres apart."

Virat is from Chamonix's Compagnie des Guides, which is to mountain guiding what Oxford University is to dictionaries. It was founded in 1821 and still meets each evening in a small chapel-like room in the centre of Chamonix, which only a guide can enter, and where they distribute the clients for the following day. Such is the reputation of the company – and such is the French approach to mountaineering – we signed no waivers and needed no assurance as to her credentials. Membership is enough.

Skiing the Vallee Blanche, we started out weaving our way through massive seracs, magnificent columns of ice in every shade of blue, and dodging the crevasses and ice falls until we reached the more even part of the glacier, the Sea of Ice, that is a little more like a freeway. Albeit a bumpy one.

We stopped half way for lunch and Virat was pointing out how global warming was eating the mountains alive. In these parts, the permafrost within them is melting and the rock faces shattering under the summer sun, falling like wafers from a biscuit.

In fresh snow, when it can be skied top-to-bottom, the Vallee Blanche is a 20-kilometre run, but this late in the season we'll stop short of that and ride a gondola lift and a train back to town. Climate change has a part to play here also; we climbed a long steel staircase to get to the lift, with various flights of stairs signposted to show where the glacier finished in decades past. The tide has turned.