Scientists have found that climate change likely played a significant role in the glacier collapse that caused devastating floods in Nepal and Tibet in late August, killing around 1,400 people and leaving thousands missing. The disaster occurred on August 26 when a massive section of glacier and rock, covering approximately 200,000 square meters, fell from the Langtang Lirung mountain, triggering an avalanche of snow, ice, and debris that descended rapidly into the valley below.
An international team of researchers, including members from Imperial College London and Utrecht University, studied the event and concluded that rising temperatures in the region had weakened the glacier and surrounding permafrost, increasing the likelihood of such a collapse. They identified July and August 2026 as the warmest months on record locally, with temperatures reaching up to 5 degrees Celsius above the 30-year average immediately prior to the disaster.
The Himalayas have experienced approximately 2 degrees Celsius of warming since pre-industrial times, with around 1.5 degrees attributed to human-caused climate change. This warming has led to a retreat of glaciers by about half a meter annually since 2000, the thawing of permafrost that supports mountain slopes, and a rise in the freezing line by roughly 100 meters per decade since the 1980s. These conditions have undermined the stability of the mountain slopes, according to the World Weather Attribution (WWA) project, a collaboration of climate experts using peer-reviewed methods to assess climate change's role in extreme weather events.
The study noted that a 7.8 magnitude earthquake that struck the region in 2015 may have further weakened the geological structure underpinning the glacier, though its precise contribution to the August collapse is unclear. In addition, unusually heavy snowfall during the late months of 2025 increased meltwater volume, potentially exacerbating the glacier’s instability.
Researchers emphasized that while climate change was not the sole cause, it served as a critical destabilizing factor in an already vulnerable geological setting. “This was a geologically vulnerable slope, potentially weakened by the 2015 earthquake, but it was destabilised further by glacier and permafrost retreat and by the excessive meltwater and exceptional warmth,” explained Walter Immerzeel, a mountain hydrologist involved in the study.
Experts highlighted the broader implications of this event, warning that without substantial global reductions in greenhouse gas emissions, similar large-scale disasters could become more frequent. “When warming destabilises the roof of the world, no amount of local adaptation can fully shield vulnerable people downstream from this scale of destruction,” said Friederike Otto, a climate scientist at Imperial College London. The disaster underlines the interconnected nature of global environmental issues, with emissions from distant regions contributing to climate effects in the Himalayas, posing serious risks to communities in Nepal and Tibet.