The study, by an international team of researchers, includes data from more than 2,000 measuring stations in six countries dating back to 1971. Previous studies have tended to look at one country at a time and to use different measuring models.
The results, published in the journal The Cryosphere, are unsurprisingly not great news, showing widespread declines in snow cover. However they did uncover different trends in different parts of the Alps and at different altitudes.
The main trend identified across the Alps was one identified previously in smaller, more localised studies: that the snow tends to arrive later than it did 50 years ago and melt away earlier in the spring.
Looking at the whole region, though, the stats also revealed that locations on the south side of the Alps, which was already less snowy, saw a faster decrease in average snowfall than those on the north side.
Snow depths were found to have “decreased significantly” in winter (December–February) at 82% of all measuring stations, with the decrease even worse in spring (March–May) with 90% of all stations recording a decrease.
In terms of snow cover, below an altitude of 2,000m, the number of days with snow has reduced by 22 to 27 days in the north and by 24 to 34 days in the south compared to the 1970s. The greater decrease was recorded at lower altitudes. Overall, depending on the altitude, this corresponds to a decrease of 10% to 35% in winter and as much as 30% to 50% in spring.
More than 20 different institutions from Austria, France, Germany, Italy, Slovenia and Switzerland took part in the study, which was led by the Italian institute Eurac Research.
The research is now freely accessible so it can be used in the future by other researchers for their own studies into snow melt or climate change.