As rescue efforts in Nepal and Tibet continue scientists say the events of the past week highlight the growing threat of climate change on the world’s environment.

The devastating flash floods have claimed over one thousand lives with the likelihood that the figure will significantly increase amid little information being released from Tibet by the Chinese authorities. However, scientists said the flooding is another major warning of the impact of climate change.

Professor Maria Shahgedanova, professor of Climate Science at the Department of Geography and Environmental Science, University of Reading, said: “We now believe that the Rasuwa flood was triggered by a large rock and ice avalanche at around 5,200m above sea level, when a huge section of glacier and the underlying bedrock, estimated to be between 1 and 1.3km wide, detached from the Lirung massif.

“The avalanche rapidly carried large volumes of ice, rock and sediment downslope. On reaching the valley floor, it interacted with deposits from a previous flood, the 2025 Purepu glacial lake outburst flood, temporarily damming the river. The failure of this temporary blockage released water and debris as a powerful flood wave.

“Researchers from the HiRisk project, which investigates cryosphere-related hazards in High Mountain Asia, suggest that longer-term glacier retreat and permafrost degradation may have contributed to slope destabilisation. The failed glacier retreated by approximately 450m between 1990 and 2020, potentially reducing the mechanical support provided by the glacier to the underlying rock slope. Permafrost degradation may have further contributed to instability. The warmer than average temperatures observed in the area this summer might have contributed to the glacier collapse too, although observations at these elevations remain limited.

“The event demonstrates how climate-driven changes in the cryosphere can change conditions that make hazards in high-mountain regions even more risky for people in the area. Such events cannot be prevented, but their impacts can be reduced through systematic hazard assessment and monitoring.

“High-resolution satellite observations and InSAR, a type of satellite-based radar that detects small changes in the earth’s surface, can identify changes in glaciers and slope stability and contribute to early-warning systems, particularly in remote mountain regions where conventional monitoring is limited.

” While the initial avalanche at Rasuwa was too rapid to provide substantial warning, longer warning times downstream could potentially have reduced loss of life.”.

Dr Matt Westoby, associate professor of Physical Geography, University of Plymouth, added:  “High Mountain Asia is one of the fastest warming regions globally. It hosts rapidly melting glaciers, growing meltwater lakes and some of the world’s steepest mountains. As the climate warms, shrinking glaciers and thawing frozen ground can destabilise mountain slopes, increasing the risk of rockfalls, landslides and avalanches. These can trigger devastating ‘hazard cascades’ – essentially chain reactions – releasing huge volumes of water, mud and debris into valleys where vulnerable communities and vital infrastructure are often highly exposed, creating a high degree of risk.

“Climate change is making many high-mountain areas around the world more unstable, with increasing reports of landslides, ice and rock avalanches, glacier collapses and resulting hazard chains. In places like High Mountain Asia, more people and infrastructure, such as hydropower, are moving into mountain areas, increasing the potential impacts. However, extreme events are rare and records are limited, so it is still difficult to say exactly how much climate change is increasing the frequency or size of individual hazards.

“A future flood on the scale of what we’ve seen in Nepal/Tibet is possible, so improving early warning and evacuation plans is essential. Seismic and other monitoring systems could quickly detect that something has happened, while mobile-phone networks can help get reliable warnings to people rapidly. People also need to know exactly what to do and, most importantly, where to go to stay safe, with evacuation routes, drills and safe places prepared in advance; this is easier for known glacial lakes, where flood arrival times and likely size can be predicted. Monitoring unstable glaciers and slopes may also help identify potential problems before they happen, although predicting exactly when a slope or glacier will fail remains extremely difficult.”

“A big question is whether these events are increasing in frequency and magnitude due to warming of the high mountains,” said Professor Hugh Sinclair, personal chair in Surface Geodynamics, University of Edinburgh. “No single event can be attributed to climate change, but the trend is worrying. Melting is driving collapse of the high Himalayan glacial valleys, and this is likely to accelerate with global warming.”