Swiss glaciers 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, reveals a study published Thursday, September 28.
The lack of snow in winter and very high temperatures in summer cost these masterpieces of nature at risk 10% of their volume between 2022 and 2023, notes the group of experts responsible for studying the cryosphere within the Swiss Academy of Sciences. Their conclusion is clear: "Swiss glaciers are melting faster and faster.»
More likely extremes
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 is a combination of the very bad succession of weather extremes and climate change" that makes these extremes more likely, Matthias Huss, who heads the Swiss glaciological survey network (Glamos), told AFP.
If we continue at the pace we have experienced in recent years – everything is going even faster – every year will be a bad year," he said. "And we have seen such strong changes in the climate in recent years, that it is quite possible to imagine this country without glaciers," admits the scientist, who nevertheless stresses that decisive action to "stabilize the climate" by reducing CO2 emissions to zero as quickly as possible could make it possible to preserve "a third of the ice formed in Switzerland".
This means "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 regions of the Alps and some glaciers that we can show our grandchildren," Huss said.
Water tower of Europe
The melting has affected the entire Alpine country, which is considered the water tower of Europe thanks to its 1400 glaciers that feed countless lakes, rivers and streams.
In southern and eastern Switzerland, glaciers have melted almost as much as in the record year 2022. Thus, in the south of Valais (south) and in the Engadine (east), a melting of the ice of several meters was measured at more than 3200 meters, while the glaciers were still in equilibrium at this altitude a few years ago.
The high temperatures this summer in Switzerland have pushed to records the limit – or isothermal – of zero degrees, at 5298 m, a level higher than the highest point in the country, Pointe Dufour (4636 m). In the winter of 2022/2023, very little snow had already fallen on both sides of the Alps and it had been very hot. As a result, there was much less snow than usual in all resorts.
Above 1000 meters altitude, during the first half of February, the measured snow depths were generally a little higher than during the low snowy winters of 1964, 1990 or 2007. But melting reached new records in the second half of February, and snow depths were only about 30 percent of the multi-year average.
Also above 2000 meters, more than half of the automatic stations with measurement series of at least 25 years had new minimum records. The dry and very hot June melted the snowpack 2 to 4 weeks earlier than usual. Conditions that have prevented the regeneration of glaciers.
According to the Intergovernmental Panel on Climate Change (IPCC) published last year, melting ice and snow is one of the 10 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 - the most ambitious goal of the Paris climate agreement.