Emerging hazards in the Italian Alps under climate and environmental change

As is well known, global warming and consequent environmental changes are rapidly changing natural hazard scenarios, especially at high elevation, where the cryosphere is degrading at an accelerated rate. The increasing frequency of natural instability processes at high elevation and their change in seasonality are now well-established globally. In recent years, a growing attention has been paid to unprecedented process chains (e.g., the collapse of the Birch Glacier in 2025 in Switzerland or the huge Mount Meager event in 2010 in Canada). However, in recent years, some unusual instability processes in the Italian Alps highlighted emerging hazards that deserve further investigation. Over the three-year period from 2021 to 2023, and with intensification in 2024, the Rin da Clus torrent (Livigno, Central Italian Alps) was affected by recurring debris flow events, even in the absence of rainfall, triggered by the rapid thawing of the frontal sector of a rock glacier. In June 2024, and again in September 2024, the proglacial areas of numerous Alpine valleys in the Western Alps were devastated by an intense meteorological event, extraordinary for high mountains, which caused widespread and sometimes extreme torrential processes, initiated in Little Ice Age deposits. The most emblematic event was the collapse of the LIA frontal moraine of the Northern Grandes Murailles Glacier (Aosta Valley), which mobilized nearly 2 million cubic meters of debris. Finally, in July 2025, a portion of the debris talus on a permafrost slope in Val di Rhemes (Western Italian Alps) suddenly collapsed. Although these are isolated events and sometimes small (as in the case of the Livigno debris flows and the Val di Rhemes collapse), these phenomena draw attention to the effects of global warming on the stability of debris accumulations, which in high mountains are often steep enough to be potentially susceptible to instability. In fact, very little is known about the distribution and thermal conditions of ground ice, while the volumes of debris that can be mobilized are rarely known. These phenomena deserve careful consideration in the coming years, given the extent of debris covers in high-elevation areas, their susceptibility to instability because of slope and lack of vegetation, and the great distances that the resulting debris flows can travel.