Devastating flash floods and mudslides have caused widespread destruction along the Nepal-Tibet border, sweeping away buildings, bridges, and roads, and leaving hundreds of tourists missing. Officials in China-controlled Tibet have expressed fears of significant casualties.
Scientists attribute the catastrophic nature of these floods to a "complex chain of hazards," according to Professor Liz Stephens, Professor in Climate Risks and Resilience at the University of Reading. While heavy rainfall is a common cause of flash floods, high-mountain regions like Nepal and Tibet can experience more intricate scenarios. These can involve landslides, avalanches, and glacial lake outburst floods (GLOFs), which make early warning systems particularly challenging.
Early reports suggest that a 4.4-magnitude earthquake may have triggered an ice avalanche. This avalanche, in turn, is believed to have blocked the Lhende River, leading to a buildup of water. When this natural dam failed, it unleashed a devastating torrent of water and sediment downstream.
"One way this can happen in steep mountain valleys is when a landslide blocks a river, allowing water to build up behind it," Professor Stephens explained. "If that landslide dam, then fails, it can cause a sudden, devastating release of water and sediment downstream."
The role of climate change in this specific event remains unclear. However, a study published in Frontiers in Climate highlighted that rising temperatures in the Himalayan region are accelerating glacier melt and increasing the risk of GLOFs. Researchers noted that warming rates in the Himalayas exceed the global average, intensifying climate-related hazards.
Scientists have previously linked climate change to intensified flooding in Nepal. Following floods in 2024, researchers from World Weather Attribution stated that climate change had exacerbated their severity. "If the atmosphere wasn't overloaded with fossil fuel emissions, these floods would have been less intense, less destructive and less deadly," said Mariam Zachariah, a researcher at Imperial College London.
Experts warn that as global temperatures continue to rise, such catastrophic flood events could become more frequent. "Climate change is no longer a distant threat," stated Roshan Jha, a researcher at the Indian Institute of Technology in Mumbai. "With every fraction of a degree of warming, the atmosphere can potentially hold more moisture, leading to much heavier downpours, and catastrophic floods like these."
Authorities have confirmed the recovery of 55 bodies, with fears that the toll will rise as search and rescue operations continue. Terrifying footage has emerged showing large waves of water and mud crashing through towns and obliterating infrastructure, including the Gyirong Port land crossing in Tibet.
Flood alerts have also been issued in northern Indian states bordering Nepal, including Uttar Pradesh and Bihar, due to concerns that rivers flowing from the mountains could cause further flooding in their plains.
Nepali officials reported that hundreds of tourists and trekkers are currently unaccounted for, including 341 foreign nationals and at least 93 Nepali citizens. Among the missing are nationals from the UK, India, South Africa, Malaysia, the United States, Australia, and the Netherlands.