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A scientific study has revealed that climate change played a significant role in triggering the devastating rock-embedded avalanche that caused flooding in Nepal and Tibet’s border areas.
Dr. Friederike Otto, a climatologist at Imperial College London and co-author of the study, stated, “There is no doubt that human-induced climate change undoubtedly contributed to the conditions that led to this disaster.”
According to the study by World Weather Attribution, this disaster was a “compound event” caused by a combination of rising temperatures, thinning glaciers, melting permafrost, and pre-existing geological vulnerabilities.
Nepali officials released this conclusion just as the number of missing people due to the flooding from Tibet impacting the Bhotekoshi and Lower Trishuli Rivers was revised upward to 6,150.
Earlier, government bodies had reported only 5,179 missing individuals. Official figures indicate around 1,400 deaths, with thousands displaced by the floods.
What Are the Other Contributing Factors?
In the border region between Nepal and Tibet, extensive flooding and landslides swept away thousands of homes and damaged infrastructure linked to various hydropower projects.
Scientists point out that the flood was caused by the collapse of a rock face and glacier near the summit of the Langtang Lirung mountain on the Nepal side.
According to data from the U.S. Geological Survey (USGS), the debris pile from this collapse generated tremors measuring a magnitude of 5.2 near the valley.
The World Weather Attribution report published Thursday notes that climate change was “a factor influencing the pre-existing geological sensitivity” but was not the sole cause of the disaster.
The study explains that due to human impacts on the climate, the temperature in the avalanche zone during July and August was nearly 1.5 degrees Celsius higher than normal.
Glaciers in the area have been thinning at a rate of about half a meter annually, which may weaken glacier crevices and increase instability.
Heavy snowfall in October and November added substantial meltwater earlier in the year.
Scientists conclude that these combined factors amplified the “compound event” significantly.
Possible Link to 2015 Earthquake
The study also suggests that the powerful 7.8-magnitude earthquake that struck Nepal in 2015, which triggered avalanches, might have weakened the rock masses that later succumbed.
However, officials have yet to confirm the specific impact of that earthquake on the recent disaster.
Dr. Walter Immerzeel, a mountain hydrologist at Utrecht University and co-author of the report, described the region as a “geologically very sensitive cliff.”
He explained that the 2015 earthquake likely weakened the area, and ongoing glacier and permafrost melting has further destabilized it.
Study Methodology
The research has not yet been published in a peer-reviewed scientific journal.
However, according to the World Weather Attribution website, the organization analyzes weather-related events using peer review processes for its studies.
Its conclusions align with findings previously highlighted by experts in the field.
Earlier, some scientists had suggested to the media that rising Himalayan temperatures could have contributed to the glacier collapse.
Dr. Simon Cook, a glaciologist at Dundee University, noted last month that although it is difficult to link a single event to climate change, “warming does make high mountain environments less stable.”
Speaking Wednesday, Cook described the World Weather Attribution study on the recent disaster as “a very valuable piece of research.”
He added that while the study provides “clear evidence that climate change was a major factor,” understanding the entire process requires much more investigation.
Additional research is needed regarding the mechanisms involved and how monitoring in high mountain areas can improve early warning for such events in the future.”
Prime Minister Traveling to New York to Advocate for ‘Climate Justice’
Following the catastrophic floods, Nepali officials have urged global collective action against climate change.
Although Nepal is a low greenhouse gas emitter, officials frequently highlight that the country is among the most vulnerable to the adverse effects of global temperature rise.
Prime Minister Balendra Shah ‘Balen’ is expected to raise the recent disaster and issues of ‘climate justice’ during the upcoming United Nations General Assembly in New York next week.
This will be his first overseas visit nearly six and a half months after taking office as prime minister.
