The images from Nepal and Tibet are almost impossible to comprehend. A raging mass of water, mud, ice and rock swept away people, homes, roads and bridges. Hundreds were killed and many remain missing. Entire communities have been devastated. Before anything else is said, it must therefore be recognised that this is a terrible human tragedy.

Precisely because the disaster is so grave, reporting it requires care. Yet climate change was invoked as an explanation within hours. The Guardian led with the headline “Climate crisis could be destabilising mountain areas like Nepal”, while CNN immediately placed the event in a climate frame. Professor and disaster researcher Roger Pielke Jr. shared the CNN segment with a pointed question: whatever happened to reporting the news before drawing conclusions?

What ever happened to reporting the news?

CNN gets just about everything wrong about the Tibet disaster in an effort to explain that climate change caused the event

This is so bad https://t.co/iUd9hRzTfk

— The Honest Broker (@RogerPielkeJr) August 26, 2026

What do we know so far?

Satellite imagery and initial reconstructions indicate that an enormous mass of ice and rock detached high in the border region. It fell through a large vertical distance, entrained sediment and water and transformed into an exceptionally fast debris flow. The recorded seismic signal was initially interpreted as an earthquake, but was almost certainly generated by the collapse itself.

The exact sequence is still being reconstructed. There is no evidence that the event began with the failure of a pre-existing glacial lake. Nor has it been established why the ice-rock mass became unstable at that particular moment, or what roles were played by local geology, glacier dynamics, water pressure, snow, temperature and precipitation. Landslide specialist Dave Petley wrote the next day that an international team had only just begun investigating.

Meteorologist Chris Martz, the 2,000th signatory of Clintel’s World Climate Declaration, offered the appropriate scientific stance: many questions remain unresolved and rigorous analysis will take weeks at a minimum, not a day or two. In a short video, Lucy Biggers shows how quickly online discussion moved from tragedy to political blame while historical context and resilience disappeared from view.

Tony is correct.

Anyone blaming “climate change” for the glacial lake outburst flood in Nepal is running a fool’s errand at this point.

There are a lot of unresolved questions at this point, and we aren’t going to have the answers to them a day or two after it occurred.

The… https://t.co/I7edWD8r8s

— Chris Martz (@ChrisMartzWX) August 27, 2026

A centuries-old mountain hazard

Ice-rock avalanches, glacier detachments, natural river dams and sudden glacier floods are not new. In some events a glacier or mass of rock and ice collapsed; in others a natural dam of ice or moraine failed. The latter is called a glacial lake outburst flood (GLOF): a sudden flood caused when a lake dammed by glacier ice or moraine debris rapidly drains.

The examples below are not intended as a complete global inventory. Each meets at least one of three criteria: it is old and well documented, occurred in Tibet or the Himalayas, or involved a similar cascade of ice or rock, river blockage, debris flow and severe downstream damage.

The Saint-Gervais thermal baths after the 1892 Tête Rousse disaster.
Unknown photographer; public domain via Wikimedia Commons.

A scientific inventory described around twenty sudden, large-volume glacier detachments and concluded that they are rare but probably more frequent than researchers once realised. Sedongpu in Tibet (2018) and Chamoli in India (2021) also produced major cascading disasters.

World Climate Declaration signatory Jim Steele points to the Himalayas’ exceptionally active geology. Colliding tectonic plates continue to uplift the range, earthquakes fracture rock and glacial ice, and Langtang’s steep faces naturally produce avalanches. In 2015, an earthquake caused a deadly avalanche on the other side of Langtang Lirung. This does not prove that climate can play no role, but it shows why local geology and topography must be investigated before CO₂ is designated the decisive cause.

Meteorologist Joe Bastardi has also compiled examples of GLOFs and landslide-created natural dams in Tibet, Nepal, India and Peru. His broader historical point is useful: these cascading disasters have a long history. We do not, however, adopt his description of the present event as a “dam burst”, because the best evidence currently identifies an ice-rock avalanche as the initiating event.

More frequent, or more frequently observed?

A cluster of recent reports is not a reliable trend. Before continuous satellite observation, events in remote mountain regions often went unrecorded. A roughly 40-million-m³ Tibetan glacier detachment in 2022 was itself identified only retrospectively from satellite and seismic data.

Warming can nevertheless alter conditions. Glacier retreat, thawing permafrost and additional meltwater can locally destabilise slopes or increase water pressure beneath ice. But slope, geology, soft sediments, snowfall, water pressure, glacier dynamics and earthquakes also matter. Failure usually results from a rare combination of factors.

In 2019, the IPCC concluded that observations of slopes, landslides and glacier instability in high mountains were too limited to detect general trends. At the same time, it projected that retreating ice and disappearing permafrost could increase instability in some places. Both findings can be true. A future projection is not a proven explanation of this disaster.

Greater losses do not necessarily mean more extreme nature

The scale of a disaster is determined by hazard, exposure and vulnerability. Populations have grown, mountain valleys are used more intensively, and homes, hotels, roads, bridges, border facilities and hydropower plants have been built along rivers. More people and assets therefore lie in potential avalanche and debris-flow paths.

An enormous collapse in an uninhabited valley may kill nobody and, in earlier times, might never have been recorded. A smaller event above a developed river corridor can become a national disaster. Rising fatalities or monetary losses therefore cannot by themselves demonstrate that the natural hazard has become more frequent or intense.

Investigate first, protect people now

Later research may show that regional warming contributed to the instability. Local geology, water pressure and topography may prove decisive. Most likely, several factors interacted. At present, we simply do not know.

The victims deserve compassion and an accurate investigation, not a rushed climate verdict. Practical lessons need not wait: map unstable glaciers and slopes, monitor them using satellites and ground sensors, install warning systems, prepare evacuation plans and exercise extreme caution when locating new settlements and critical infrastructure in known runout zones. Global climate targets cannot eliminate this centuries-old mountain hazard. Effective adaptation can save lives.

Aerial view of the Huascarán avalanche path that destroyed Yungay in 1970.
NOAA/USGS; public domain via Wikimedia Commons.

Key sources

• Dave Petley, initial analysis
• Kääb et al., inventory of large glacier detachments (2021)
• IPCC, High Mountain Areas (2019)
• Tielidze et al., historical Devdoraki disasters
• Khanal et al., historical GLOFs in Tibet and Nepal
• USGS, Glacier Hazards in Peru