Switzerland’s glaciers are on track to experience one of their worst years for ice loss as an intense European heatwave accelerates melting across the Alps. Scientists expect the country to reach its annual “glacier loss day” by Monday, making it the second-earliest such date since records began in 2000.
Glacier loss day marks the point at which all the snow and ice accumulated during the previous winter has melted. From that day until the end of the melt season in October, every additional day of warm weather results in a net loss of glacier ice.
“We’re just seeing enormous ablation, ice melt rates and snow melt rates all over the Alps,” Matthias Huss, head of Glacier Monitoring in Switzerland (GLAMOS), said on Friday.
“We are three months too early compared to a healthy state,” he added.
Heatwave Speeds Up Glacier Retreat
The only earlier glacier loss day on record occurred on June 26, 2022, which remains the worst year for Alpine glacier melt. Scientists say this year’s rapid melting has been driven by a combination of an intense summer heatwave, unusually high temperatures in May, and below-average snowfall during winter.
Huss recently visited the Rhone Glacier and observed that approximately one metre of ice had melted vertically within just 10 days.
“It’s very impressive to see, and this is just the effect of the heatwave,” he said.
He warned that prolonged periods of unusually high temperatures pose a greater threat than isolated heatwaves.
“The problem is rather that we have very high temperatures that last for a very long time,” Huss said, describing extended heat as especially damaging for glaciers.
Low Snowfall and Sahara Dust Add to the Crisis
Scientists say conditions this year closely resemble those of 2022.
Switzerland received around 25 per cent less snowfall on its glaciers than the average recorded between 2010 and 2020. An unusually warm May caused snow cover to disappear earlier than normal, exposing darker glacier ice that absorbs more sunlight and accelerates melting.
Huss also identified dust carried from the Sahara Desert in March as another contributing factor. The dust darkened the snow’s surface, reducing its ability to reflect sunlight and increasing heat absorption.
Although the total ice loss will be assessed in September, Huss said it is already evident that Switzerland will experience another year of substantial glacier shrinkage.
Climate Change Behind Rising Temperatures
Scientists increasingly attribute Europe’s record-breaking heatwaves to human-induced climate change.
A rapid attribution study by the World Weather Attribution group concluded that the current heatwave would have been virtually impossible without global warming caused by human activities. Similar extreme heat events are now estimated to be around 200 times more likely than they were just two decades ago.
Researchers described the ongoing event as the most severe heatwave ever recorded across the regions included in the study.
They also found that comparable heatwaves during the 1970s would have been several degrees cooler. Europe, the world’s fastest-warming continent, has experienced temperature increases at roughly twice the global average since the 1980s.
Scientists continue to warn that greenhouse gas emissions from burning fossil fuels are making extreme heat events both more frequent and more intense.
Thousands of Glaciers Already Gone
Swiss glaciers have been retreating for nearly 170 years, but the pace of melting has accelerated significantly in recent decades due to rising global temperatures.
Between 2000 and 2024, Switzerland lost approximately 38 per cent of its total glacier volume.
According to Huss, the country has already lost around 1,200 glaciers over the past 50 years, leaving only about 1,300 remaining.
“If warming continues as it did over the last decades, by 2100 we will only be left with some little remnants of ice,” he warned.
The shrinking glaciers also pose long-term risks to Europe’s water resources. Meltwater from the Swiss Alps feeds major rivers, including the Rhine and the Rhone, making the continued loss of glacier ice a significant concern for freshwater supplies across the continent.
