Skiers might have to wait until at least January to get on the slopes in future, scientists have warned. They say global warming could kill off snow any earlier.
Predictions for Switzerland show more moisture will fall in the winter - but the earlier falls will be rain, not snow, by 2100. Most resorts rely on 100 days of snow cover from December through to the end of February.
And although at the moment some resorts can use snow guns to top up the cover in warmer winters, scientists believe increased temperatures will also put an end to that. There are also fears the cost of water used to make snow, coupled with it only being viable in the higher resorts, will make skiing holidays too expensive for most.
Dr Erika Hiltbrunner from the Department of Environmental Sciences at the University of Basel and colleagues looked at one of Switzerland’s largest ski resorts, Andermatt-Sedrun-Disentis. They calculated the extent to which this ski resort can maintain its economically important Christmas holidays and a ski season of at least 100 days with and without snowmaking.
The team collected data on the aspects of the slopes, where and when the snow is produced at the ski resort and with how much water. They then applied the latest climate change scenarios in combination with simulation software for projections of snow conditions with and without technical snowmaking.
According to the results, the use of technical snow would still guarantee a 100-day ski season but only in the higher parts of the ski resort above 1,800 metres. Writing in the International Journal of Biometeorology they say that in one scenario with unabated greenhouse gas emissions, the Sedrun region of the resort will no longer be able to offer guaranteed snow over Christmas.
Dr Hiltbrunner said: "Current climate models predict that there will be more precipitation in winter in the coming decades, but that it will fall as rain instead of snow."
And she added: “Many people don’t realise that you also need certain weather conditions for snowmaking. It must not be too warm or too humid, otherwise there will not be enough evaporation cooling for the sprayed water to freeze in the air and come down as snow.
"Warm air absorbs more moisture and so, as winters become warmer, it also gets increasingly difficult or impossible to produce snow technically."
The higher slopes will still be able to offer skiing in 2100 but it will come at a cost, the researchers say. Their calculations show that water consumption for snowmaking will increase by about 80 per cent for the resort as a whole.
In an average winter toward the end of the century, consumption would thus amount to about 540 million litres of water, compared with 300 million litres today. And this will lead to competition for water with hydroelectric demands.
A maximum of 200 million litres may be withdrawn annually from the nearby lake, Oberalpsee, for this purpose. Dr Maria Vorkauf, lead author of the study, who now works at the Agroscope research station, said: "If climate change continues unabated, this source of water will last until the middle of the century, at which point new sources will have to be exploited.
"The Oberalpsee is also used to produce hydroelectric power. Here, we are likely to see a conflict between the water demands for the ski resort and those for hydropower generation."
But ultimately tourists will foot the bill. Dr Hiltbrunner said: "What is certain is that increased snowmaking will drive up costs and thus also the price of ski holidays."
