The findings of a new study shows governance and preparedness rather than hazard magnitude determine whether avalanches become mass-casualty events.
With large ice-rock avalanches growing in frequency as steep slopes in the Himalaya become unstable due to rapid glacier retreat, extreme precipitation and permafrost degradation, scientists believe saving lives, protecting infrastructure and reducing long-term economic losses in some of the world’s most hazard-exposed regions could be achieved through several practical steps.
Published in Nature’s Earth and Environment journal, the international study involving scientists from the Department of Planetary Sciences at the University of Aberdeen compares two major ice–rock avalanches: the 2021 Chamoli disaster in India, which killed more than 200 people, and the 2025 Blatten avalanche in Switzerland, which buried much of the village but resulted in minimal loss of life.
Despite the events being similar in manifestation, the outcomes could not have been more different. The research concludes that the decisive factor was preparedness.
“Mountain disasters are not just natural events, they are governance tests,” said co-author Dr Anshuman Bhardwaj from the School of Geosciences at the University of Aberdeen.
“Chamoli showed what happens when warning signs are missed. Blatten showed that even extreme hazards can be survived when risks are anticipated and systems are ready.”
The Swiss village of Blatten benefitted from continuous slope monitoring, clear evacuation protocols and high community awareness. When warning indicators intensified, local authorities were able to trigger rapid evacuations, enabling residents to escape before the avalanche struck.
In contrast, Chamoli had no such operational monitoring systems and anticipatory governance framework. Warning signs went unnoticed and communities were not equipped with decision protocols or evacuation pathways.
The research concludes that the size of the hazard was not the determining factor. It was the presence or absence of anticipatory systems that proved vital.
“Climate warming is rapidly destabilising glaciers and high-altitude slopes, making cascading ice–rock avalanches more frequent and unpredictable. Yet disaster-management systems in the Himalaya remain largely reactive, often based on outdated hazard categories that do not reflect the speed or complexity of evolving cryospheric events,” added co-author Dr Lydia Sam, also of the University of Aberdeen.
The research is among the first to frame ice–rock avalanches as governance challenges rather than unpredictable natural surprises. While early warning systems exist for floods and cyclones, few comparable frameworks address mountain hazards that can evolve within minutes-to-years.
The study argues for a shift toward anticipatory governance and outlines five practical steps to close the preparedness gap, offering a roadmap for Himalayan governments, development partners and local communities.
They recommend including integrated satellite and ground-based monitoring, clear and actionable decision thresholds, rapid communication pathways, decentralised authority to trigger evacuations; and strong community-linked preparedness systems.
“Many cryospheric disasters in the Himalaya do not have to become mass‑casualty events,” concluded lead author Dr Rayees Ahmed of the Divecha Center for Climate Change at the Indian Institute of Science. “The cost of preparedness is far lower than the cost of catastrophe.”
The study ‘An interdisciplinary analytical framework for high-mountain landslides and cascading hazards: implications for communities and infrastructure’ was supported by the UK Research and Innovation (UKRI) Natural Environment Research Council (Grant ref NE/Z503502/1); the Ministry of Earth Sciences (MoES)-India; and the University of Aberdeen’s Impact & Engagement Accelerator Fund.
The reports’ authors are Dr Rayees Ahmed from the Divecha Center for Climate Change at the Indian Institute of Science, India; Dr Anshuman Bhardwaj and Dr Lydia Sam from the University of Aberdeen, UK; and Dr Lander Van Tricht from the Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zürich, Switzerland.