Heat waves have melted some of the permafrost that held the steep rock faces of the Alpine peaks together, leaving collapsing walls.

Climate change is increasingly becoming a threat to the snow-clad European Alps, amid initial investigations associating the August 26 Nepal tragedy with rising temperatures.

Mont Blanc's glaciers are rapidly retreating due to climate warming and heat waves. Permafrost is thawing, causing increased rock falls and instability on mountain slopes. This…