In graphics – How climate change reduces snow cover in ski resorts

Mid-latitude stations are not much better off. That of Grimentz for example, located in the heart of the Valais Alps in the Val d’Anniviers (1560 meters above sea level), is experiencing a notable reduction in its snow cover. Between 1960 and 1990, the maximum snow depth averaged 70 cm. Since the 1990s, this average has fallen to around 47 cm, a drop of almost a third. Note that these measurements take place in the village, these figures reflect the minimum natural snow cover of the resort.

The changes are not limited to the thickness of the snowpack: melting now begins almost a month earlier than during the period 1960-1990. Thus, in mid-April, Grimentz retains on average less than 5 cm of snow, compared to 25 cm previously. If the white gold disappears earlier and earlier, the start of the season remains relatively stable.

The high mountains still preserved

Above 2000 meters, the changes are less obvious, although the trend remains visible. At the Weissfluhjoch, at 2540 meters above sea level in Davos, the maximum snow depth increased from 2.2 meters (1961-1990) to 2.1 meters (1990-2024). This modest decline contrasts with the drastic losses observed at lower altitudes.

However, even in high mountains, the duration of snow cover decreases. Almost all stations show a clear decrease in days with snow-covered ground, regardless of their altitude and position.

The evolution of the zero degree isotherm, an altitude where the average temperature reaches 0°C, perfectly illustrates the effects of climate change. Today it stands at around 850 meters in winter, 250 meters higher than 50 years ago. It could rise by an additional 400 to 650 meters by 2060, and therefore be between 1300 and 1500 meters, if no significant action is taken to reduce greenhouse gas emissions.

Even less snow in the future

At these higher altitudes, precipitation will occur more and more often in the form of rain, particularly at the beginning and end of winter. At 2500 meters, the total amount of snow could decrease by 30% by 2060.

The SLF projections for the end of the century are particularly worrying for white gold lovers. Without a reduction in emissions harmful to the climate, the natural snow cover would decrease by up to 70% and the ski season would begin a fortnight or even a month later than today. Only resorts located above 2500 meters would benefit from sufficient natural snow cover for profitable exploitation of their area.