The tragic Nepalese flood is the climate’s alarm clock rather than the slow creep of incremental changes that we can more easily ignore. What happened there, and why did it result in over a thousand deaths, with many thousands more still missing?
I’m not a glacier hazard expert so I will leave the technical explanation of the collapse and subsequent landslide to others. What I can tell you, as a snow hydrologist that studied meltwater hydrology in the Langtang and Trishuli basins, is that this is an incredibly steep and dramatic landscape with soil, rock, snow and ice (glaciers) that historically has been somewhat locked into place by frozen water. As the permafrost thaws from its solid structure, and snow fields and glaciers produce more meltwater to lubricate bedrock and saturate soils, these slopes are increasingly unstable. Events like we saw in August may well become more common.
People live in these areas. Why were they not warned? Early warning systems have been installed by the Nepali government in many glacierised river systems, especially those that are downstream from terminal lakes. Glacier Lake Outburst Floods (GLOFs) are the hazard of concern there (but that’s another story). I understand from respected Nepali glaciologist, Dr. Rijan Bhakta Kayastha, that the Trishuli did have early warning system sensors in place that measure rapid changes in water levels, but that these sensors were washed away before any data could be transmitted. Anyone who has seen the footage of the flood front can appreciate this was not a detectable rise in water level over seconds to minutes. It was instantaneous, and it took the sensors with it. Alternative early warning system approaches like field cameras are now being considered.
The other problem is the sheer scale of the early warning task. Nepal has more than 3,800 glaciers, and more than 2,000 glacial lakes. That’s a lot of monitoring, and a lot of money. The Langtang basin is relatively accessible for Himalayan standards as it was a popular trekking route, and has a history as a cryospheric research area for Nepali and foreign scientists alike. If we can’t anticipate the climate-induced hazard and impact to communities here, do we think we can actually tackle this across the entire Himalaya?
It can be easy to just focus on the flooding and extreme weather events at home in our own mountain communities in Aotearoa but it’s important we consider those living in other mountain communities globally where melting glaciers, and extreme flooding events are having much greater tolls. Climate pollution doesn’t stay in one place, it’s shared by the whole world and impacts those with the least resources the most. What’s been potentially a positive from this tragic event, is that climate change has been in the headlines of mainstream media. The Kiwi-Himalaya connection has resulted in about $180,000 dollars being donated to the Himalayan Trust for flood relief. If you would like to donate too, you can do so here. The New Zealand Red Cross has started a Nepal flood emergency appeal here, and Oxfam NZ had a flood appeal here. If you’re able, please donate to help communities recover from this.
For more great thought provoking reading on this topic and more check out POW athlete alliance captain and climber Graham Zimmerman’s substack.
