Glaciers in Europe's Alps are becoming more unstable and dangerous, as rising temperatures linked to climate change are reawakening what were long seen as dormant, almost fossilized sheets of ice.
While Italy has been baking in an early summer heatwave, attention has been focused on the impact of drought on crops on the fertile Po Valley.
But further north in the Dolomites, a mountain range in northeastern Italy, tragedy struck on Sunday when a glacier collapsed on the mountain of Marmolada, killing at least six people. The mountain, reaching a height of more than 3,300 meteres, is the highest in the mountain range.
"This summer 2022 risks being the perfect storm for glaciers," said Giovanni Baccolo, an environmental scientist and glaciologist at Milano-Bicocca University in Milan, Italy.
Baccolo noted a lack of winter snow and a ferociously hot start to summer as contributing factors.
"Nobody could have expected a glacier like the Marmolada to react like this," he told Reuters. "It is a kind of climatic fossil. Glaciers like the Marmolada are considered placid, they are expected to just retreat."
Incredible footage from an helicopter of the mountain rescue of the basal detachment in Marmolada.
Water lubrication at the base (or interstrata) and increased pressure in water-filled crevasses are probably the main causes for this catastrophic event pic.twitter.com/2OXRExkdjy
—Temperatures on the normally freezing Marmolada touched 10 C on Saturday, according to Veneto regional governor Luca Zaia.
The huge mass of ice collapsed close to Punta Rocca, on the route usually used by hikers and climbers to reach the summit, the alpine rescue unit said.
"High elevation glaciers such as the Marmolada are often steep and relying on cold temperatures below 0 C to keep them stable," said Poul Christoffersen, professor in Glaciology at the University of Cambridge.
"But climate change means more and more meltwater, which releases heat that warms up the ice if the water refreezes, or even worse: lifting up the glacier from the rock below and causing a sudden unstable collapse," he added.
I think that while we know how a glacier retreats, we don't know much about how it disappears. What happened on the Marmolada today concerns a glacier considered relatively risk-free.
Non-linear failure of small glaciers may become increasingly common in the near future. pic.twitter.com/fKBsu0wWrY
—Baccolo said those intrepid hikers heading into the mountains to escape the summer heat should be careful about where they venture.
"The invitation I want to make to those who go to the high mountains this summer is to use much more caution," he said. "The problem is that it may no longer be enough to read the signs from the glacier that have been read so far."
