Climate change had major role in triggering Nepal floods, scientists say

Researchers at the World Weather Attribution (WWA) group concluded that climate change played a central role in the late-August collapse of a large section of rock and glacier from Langtang Lirung mountain, which unleashed a torrent of water, ice and debris that devastated communities downstream in Nepal and parts of Tibet. The WWA report framed the disaster as a compound crisis driven by long-term warming trends, glacier retreat, permafrost thaw and resulting geological instability rather than a single isolated weather event. The study noted that July and August were the warmest months on local record, with temperatures about 5°C above normal, and that heavy snowfall in late 2025 increased meltwater ahead of the collapse. Report co-author Walter Immerzeel, a mountain hydrologist at Utrecht University, warned the region is undergoing fundamental and irreversible shifts as glaciers retreat and permafrost degrades, weakening mountain slopes. The report also cited other contributing factors, including possible legacy damage from a magnitude 7.8 earthquake in Nepal in 2015, though it said the earthquake’s precise role in the slope failure remains uncertain. WWA’s analysis uses peer-reviewed methods to estimate the role of global warming in extreme events, and its findings have been released amid concerns about the limits of adaptation in Himalayan communities. Nepal, a largely rural country of about 30 million people that emits only a small fraction of global greenhouse gases, has put an initial reconstruction bill at $4.78 billion. Nepal’s disaster authority reported 1,403 bodies recovered in the country, 105 of which had been identified, and revised its missing count to 6,150 after local verification. Chinese state media reported 43 dead and 519 missing there, bringing the combined toll across both nations to 1,446 dead and at least 6,669 missing. Prime Minister Balendra Shah is scheduled to address the United Nations General Assembly on the issue next week, in his first foreign trip since taking office.