A lot is being said about the Nepal floods — theories, speculation, and a news cycle flooded with information. At times like this, it helps to listen to an old Himalayan hand. That is what we try to do at The Borderlens — to learn, and to help our readers understand.
In this conversation, former ICIMOD scientist Dr. Dhrupad Choudhury explains what actually happened — from a massive glacial collapse on Langtang’s northern face to the dam-burst that sent floodwaters tearing downstream. He discusses altitudinal amplification and why higher Himalayan elevations are warming faster; the role of black carbon from vehicular exhaust and industrial burning in accelerating glacial and permafrost melt; how the Langtang collapse was initially mistaken for a magnitude 5.2 earthquake before the US Geological Survey attributed the tremor to the collapse itself; and how the resulting temporary damming of the river, followed by its burst, triggered the flood downstream. He also reflects on what made the disaster worse — gaps in early warning systems, unregulated development upstream, and pollution.
