Rising temperatures increase risk of glacial floods in Nepal, scientist warns

 Kathmandu, July 31 – With rising global temperatures speeding up glacier melt, the risk of glacial lake outburst floods (GLOFs) is becoming more dangerous across Nepal’s Himalayas. This growing threat was highlighted during the eighth episode of the “Meet the Scientist” series, organized on Tuesday by the Nepal Forum of Science Journalists (NFSJ) under the theme “Rising Heat, Rising Glacial Floods in Nepal's Himalayas.”

Professor Dr. Rijan Bhakta Kayastha, head of the Himalayan Cryosphere, Climate, and Disaster Research Center (HICCDRC) at Kathmandu University, warned that the increasing number and size of glacial lakes—especially in cross-border areas like Rasuwa—pose a serious danger to downstream communities.

He presented findings from a rapid hazard assessment of the July 8, 2025 Rasuwa Glacial Flood. The flood started from a supraglacial lake on the Purepu Glacier, located in the Lendhe Catchment of the Bhote Koshi river, which lies in Chinese territory but flows into Nepal. Satellite data from Sentinel-2 confirmed that the flood began around 3:15 a.m. after the sudden outburst of a glacial lake situated at 5,160 meters above sea level.

Dr. Kayastha explained the glacier’s internal drainage system—how supraglacial, englacial, and subglacial pathways manage meltwater—and emphasized that rising temperatures are causing many lakes, like Tsho Rolpa in Dolakha, to expand quickly. “If we don’t act soon, these lakes could become ticking time bombs for people living downstream,” he warned.

The session drew participation from science journalists, researchers, and students, who voiced concern over the increasing frequency of glacial floods. Many called for stronger disaster preparedness and timely action from local and national authorities.

Chhatra Karki, Vice President of the World Federation of Science Journalists (WFSJ), praised Dr. Kayastha’s detailed explanation. “Such sessions help journalists better understand complex climate issues and report responsibly. These disasters aren’t random—they have scientific causes, and policies should be based on solid research,” Karki said.

Held monthly, the “Meet the Scientist” series aims to connect scientists, policymakers, and the public through accessible science journalism. By promoting expert dialogue, it helps raise awareness and improve early warning systems.

As climate change continues to reshape Nepal’s mountains, Dr. Kayastha concluded with a clear message: “We need better-informed communities, stronger local response systems, and science-led policies to protect our fragile mountain ecosystems and the lives that depend on them.”