The series of heatwaves Europe faced this summer took their toll on glaciers. Alec Luhn heads to Switzerland to hear about the impact I AM climbing Switzerland’s Rhône glacier when I feel a thump deep under my feet, then another. The glacier is shifting and cracking as it slides down the mountain, opening new crevasses within. Dazzling blue melt streams grow and multiply across the sooty ice. Every few minutes, melting glacial remnants on the valley wall unleash rocks that crash down with a rumble. Suddenly, the 20 metres of ice under my crampons doesn’t feel very solid. A 4-metre aluminium tube has emerged so far from the ice that it has nearly tipped over. …