Europe’s record heat melted Swiss glaciers

Originally published by E&E News

The sweltering heat wave that roasted much of Europe last month has since moved north, where it's wreaking havoc on the Greenland ice sheet. But while all eyes are currently trained on the Arctic ice, scientists are finding that Europe's coldest places have also suffered.

According to initial findings from the Swiss Glacier Monitoring Network (GLAMOS), Swiss glaciers experienced unusually high melt rates during the last heat wave, which occurred in late July, and an earlier heat wave that struck the continent in late June.

Matthias Huss, a glaciologist with Swiss University ETH Zurich and head of GLAMOS, tweeted last week that the nation's glaciers lost about 800 million metric tons of ice during the two heat waves alone.

"Absolutely exceptional for a period of only 14 days in total!" he commented in the tweet.

The estimate is still preliminary, he told E&E News in an interview. It's based on an early analysis of on-site measurements at certain sites, combined with a model that scales up the measurements to estimate total ice losses throughout the country. A more detailed analysis will follow at the end of the summer, which will estimate the season's cumulative losses and compare them to previous summers.

But the data already suggests that the losses this year have been unusually rapid.

During the winter, the region received an above-average amount of snowfall, Huss pointed out. So the glaciers actually started the summer with a high level of snow cover and were doing "extraordinarily well" compared to the last few seasons, which have logged particularly strong losses, he noted. Scientists were hopeful that they'd end the season on a better note than the last few years.

But once the first heat wave struck, the snow began to rapidly melt away.

"Now, because of these two heat waves, we have tracked very fast downward," Huss told E&E News. "And we are now at the average of the last 10 years, or even already a bit below."

Across the European Alps, other regions have also been feeling the heat this summer. The Tignes ski resort in the French Alps announced at the end of July that the nearby Grande Motte Glacier was no longer safe for skiers after this summer's excessive melting.

And about 50 miles to the north at Mont Blanc, the highest mountain in the European Alps, mountaineer Bryan Mestre was stunned to stumble across a large pond of liquid water pooled on top of the snow as he hiked through in late June. Just 10 days earlier, before the first heat wave set in, the same area had been completely frozen. His Instagram post has been widely shared by media outlets around the world.

It's the latest continuation of a long trend. According to Huss, alpine glaciers have been retreating since at least the mid-19th century. And the losses seem to be accelerating over the last few decades.

The most impressive changes have been observed at the region's largest glaciers, he noted. Aletsch Glacier, the largest glacier in the Alps, has retreated by nearly 2 miles since the year 1870.

The pattern isn't limited to Swiss glaciers. Scientists have observed declines across Europe, including glaciers in the mountains of France, Austria, and Italy. And as long as global temperatures continue to rise, the losses are expected to continue.

One recent study published earlier this year in The Cryosphere estimated that about a third of all the glacier volume in the European Alps could be lost by the year 2100, even if world nations manage to meet the climate targets outlined in the Paris Agreement. Under a scenario in which greenhouse gas emissions continue at their current levels, more than 90% of the ice could disappear.

Other studies have made similarly dire projections for mountain glaciers in other parts of the world, including the Hindu Kush and the Himalayas.

Summers like this one, marked by extraordinary heat waves and high levels of melt, only exacerbate the problem.

"Now we are really seeing almost every year another extreme year," Huss said. "And this is what is actually a problem."