The conclusion is clear: “Swiss glaciers are melting faster and faster. » A study by the Swiss Academy of Natural Sciences, published on Thursday September 28, details the “dramatic acceleration” of the melting of Swiss glaciers. According to the group of experts, they have melted as much in the last two years as between 1960 and 1990, under the effect of extreme weather conditions exacerbated by climate change.

Little snow in winter and very high temperatures in summer have resulted in a 10% decrease in the volume of these masterpieces of nature between 2022 and 2023, note scientists responsible for studying the cryosphere – l all the masses of ice, snow and frozen ground present on earth.

The extreme years follow one another and are similar: after losing 6% of volume in 2022, a record year, Swiss glaciers have melted by another 4% this year. This is the second largest decline since measurements began. “It’s a combination of the very bad succession of weather extremes and climate change” that makes these extremes more likely, explains Matthias Huss, who heads the Swiss glaciological survey network Glamos. “If we continue at the pace we have seen in recent years – everything is going even faster – every year will be a bad year,” he emphasizes.

“And we have seen such strong changes in the climate in recent years that it is entirely possible to imagine this country without glaciers,” recognizes the scientist, who nevertheless emphasizes that decisive action to “stabilize the climate”, by reducing CO₂ emissions to zero as quickly as possible, could help preserve “a third of the ice formed in Switzerland”. This means “that all the small glaciers will be gone and the big glaciers will be much smaller, but there will still be some ice in the higher parts of the Alps and a few glaciers that we can show our grandchildren », wants to hope Mr. Huss.

The Alps, “water tower of Europe”

The melting affected the entire Alpine country, which is considered the water tower of Europe thanks to its 1,400 glaciers which feed countless lakes, rivers and streams. In the south and east of Switzerland, the glaciers have melted almost as much as in 2022. Thus, in the south of Valais (South) and in Engadine (East), a melting of several meters of ice has been measured at more than 3,200 meters, while the glaciers were still in balance at this altitude a few years ago.

High temperatures this summer in Switzerland have pushed the limit – or isotherm – of zero degrees to record highs, at 5,298 meters, a level higher than the highest point in the country, Pointe Dufour (4,636 meters). During the winter of 2022-2023, very little snow had already fallen on both sides of the Alps and it had been very warm.

The very hot summer prevented the regeneration of glaciers

Above 1,000 meters above sea level, during the first half of February, measured snow depths were generally a little higher than during the snow-less winters of 1964, 1990 or 2007. But melting reached new records during the second half of February, and snow depths were only about 30% of the multi-year average.

Also above 2,000 meters, more than half of the automatic stations with measurement series of at least twenty-five years posted new minimum records. The dry and very warm month of June caused the snowpack to melt two to four weeks earlier than usual. Conditions that prevented the regeneration of glaciers.

According to the report of the Intergovernmental Panel on Climate Change, the famous IPCC, published last year, the melting of ice and snow is one of the ten major threats caused by global warming. According to another study, published in January in the journal Science, half of the glaciers on earth are doomed to disappear by the end of the century if the rise in temperatures is limited to 1.5°C compared to the pre-industrial period – is the most ambitious objective of the Paris climate agreement.