The eternal snow is less and less so, even in the high peaks of the Alps where snow sports enthusiasts rush. To thwart climate change, several resorts in Europe are now turning to the ” snowfarming », a technique that aims to put the precious snow of the previous season under a bell all summer long.
The diagnosis is clear: the snow cover is set to decrease by 30% in the Alps by the end of the century… if humanity manages to limit the rise in temperature to 2 degrees Celsius, according to a study published in Cryosphere. The phenomenon is also affecting Canada, where the snow-covered area has been declining by 5 to 10% per decade for the past 40 years.
Recycle old snow
Several international sliding sports competitions are already taking place on covers made of artificial snow, now called “culture” snow, but also on “recycled” snow from previous seasons.
During the last Cross-Country Skiing World Cup in Ruka, Finland, at the end of November, cross-country skiers were able to set off on snowy slopes in October thanks to the snow preserved from the previous winter. In 2008, in Davos, the best cross-country skiers in the world began their training on a 4 km track, made from “preserved” snow. This year, Davos Klosters was also one of the first resorts to open its slopes to athletes on 7 November. “Dank Snowfarming!” tweeted the station on Twitter.
Developed in Scandinavia, this conservation technique consists of collecting, near the slopes, at the end of winter, huge mounds of snow in natural cavities covered with a thick insulating layer of shavings or sawdust. This coat allows the reserve to stay cold, even during the summer.
The hardened snow is then collected the following fall with diggers, broken up and spread to launch the ski season as soon as the nights cool off, even if the natural snow is not there yet.
The Swiss Institute for Snow and Avalanche Research (SLF) has been testing various snow conservation techniques since 2008 in Davos to protect the future of Swiss resorts which are seeing their tourist activities increasingly disrupted. by rising mercury. Mounds of thousands of cubic meters of snow are carefully preserved in the summer and, since then, the procedures for protecting the “old snow” have made it possible to limit melting by 10 to 25% during the summer months, even in recent summers. scorching.
France is snowing up
The French summits are also beginning to take action, since the valleys without glaciers located below 2000 meters are all affected by the reduction in natural snow cover and drought. The ski area of Les Saisies in Savoie thus stored more than 11,000 cubic meters of snow last summer to help whiten its slopes at the end of autumn.
As of November 5, the small Savoyard town of Bessans, located at an altitude of 1,750 meters, also distributed 10,790 square meters of this white gold over three kilometers of track, stored all summer. “It’s not good fresh snow that has just fallen, but it’s not at all embarrassing, we adapt. And then, we are so happy to be able to ski at the beginning of November! “Explained at this time to AFP Jeanne Richard, member of the French biathlon team.
In 2018, the Women’s Alpine Skiing World Cup, held in Courchevel, benefited from 700,000 cubic meters of “old” snow stored the previous summer, to ensure better snow cover.
Goodbye guns
Why keep the snow, rather than operating the cannons?
The experience of recent years at the very posh ski resort of Kitzbühel in Austria shows that recycling snow is, in some cases, much cheaper and also more environmentally friendly than producing it in large quantities. “Snowfarming is our life insurance,” said Josef Burger, chief of snowmaking operations at the resort, to Bloomberg in 2018. The snow conservation operation is not taken lightly, because drones monitor the state of the reserve all summer long, covered with insulating foam plates.
From April, drones can locate by GPS the places where the largest volumes of snow remain on the slopes. The snowcats are then dispatched to the site to collect and move the snow to a conservation site where the white gold will be treated with great care. Expensive?
According to a report compiled by Josef Burger, it costs 30,000 euros to protect 28,000 cubic meters of snow, three times less than the 84,000 euros needed to produce the equivalent of “cultivated snow”, produced by cannons millions of cubic meters of water.
This little sleight of hand is above all very profitable for this resort, which has thus extended the duration of its ski season from 150 days to more than 200 days in a few years, despite the ups and downs in the weather. Being able to open the season before the holiday season has become a key element in attracting downhill enthusiasts. Between 2014 and 2017, the number of “passages” to Kitzbühel jumped by 234%, and the turnover linked to subscriptions increased by almost 30%.
Snow sensors
In Canada and elsewhere in North America, completely different snow cultivation techniques are used, more aimed at maximizing snow accumulations, rather than retaining them from season to season. This is the case of Sunshine Village Resort, one of three located in Banff National Park, Alberta, which receives more than 30 feet of snow per year!
Little affected by the decrease in snow cover, the high peaks of the resort nevertheless suffer from strong winds which deprive them of a thick white coat. Once solved by snow cannons, this problem is now managed by 20 to 30 kilometers of windbreak fences planted at the top in the fall, which act as snow catchers. The snow mounds formed by the wind along the fences are then stormed by the caterpillars. The beautiful powder just harvested is then distributed on the slopes.
This “low-tech” method has been used since 2016, which makes it possible to obtain light snow at low cost and of better quality than artificial snow, which is heavier, wetter and necessarily harder. “It’s pretty unique what we do here,” Sunshine operations manager Dave Riley told CBC. There are no other stations that use this technique so extensively. »
But since then, others have followed suit with other means, including Mammoth Mountain in California, which detects, thanks to a satellite dubbed SNOWsat, the snowiest places in its immense network of tracks. Equipped with electronic tablets, the caterpillar operators are then responsible for locating, using GPS data obtained by satellite, these gold mines to spread the white flakes on the slopes intended for spring skiing.
Result: this helping hand to Mother Nature is a delight for boardsports enthusiasts whose season at Mammoth ended last year under the sun… on May 31st.