Tourists visit France’s shrinking Mer de Glace glacier, where tarps slow melting as record summer heat thaws Alpine permafrost, triggers rockfalls and makes routes up Mont Blanc increasingly dangerous.

Tarpaulins cover the ice cave of the 'Mer de Glace' glacier to prevent it from melting, at the Montenvers station in Chamonix, France, Saturday, Sept. 5, 2026. (AP Photo/Laurent…

Tourists visit France’s shrinking Mer de Glace glacier, where tarps slow melting as record summer heat thaws Alpine permafrost, triggers rockfalls and makes routes up Mont Blanc…