| But apparently this was a black swan.
What is your definition of black swan? This paper is from 2022 and scientists have been warning about climate change for decades. It's not like this possibility wasn't anticipated. It seems likely we'll see more glacial events as the atmosphere warms.
There have been maybe three such events in the 21st century (glacier or landslides producing more than a magnitude 5 quake), and none of them have happened in an area like the Himalayas. The other two were in Alaska on Mt Steller in 2005 and the Lamplugh Glacier in 2016, neither of which produced massive downstream floods.
It usually takes entire icebergs calving off to produce such seismic events and intense monsoons to create such flooding.
> There have been maybe three such events in the 21st century
It seems that past history (especially recent) will not be a good predictor of future events.
Spoiler alert: that’s the whole point of a black swan event.
A black swan event is an event that is unpredictable because it is so rare.
While I'd wait for confirmation about the cause of this specific incident, the point you seem to be ignoring is that, due to climate change, events that would have been considered "black swans" historically will become more and more common, to the point that they are expected to occur.
I think that’s a misreading of the entire book. A black swan event is a rare, high-impact outlier that is nearly impossible to predict under normal circumstances, but is rationalized as having been inevitable in hindsight.
For whatever reason, you continue to try to ignore the point I'm making, which is that, in terms of natural disasters related to climate in particular, what would have been "rare, high-impact outlier[s]" are increasingly becoming common enough to be not rare and not outliers.
And you continue to ignore what I said (and what the book said). The whole point of a black swan event is exactly what you just described.
It’s the inflection point when our priors change.
Maybe I misunderstand (either you or the topic in general) but I don't think what you're saying is correct. A black swan event is (to my understanding) something unexpected and generally remains so. Not (as you seem to be suggesting) "oh hey that was historically unexpected but going forward it's now considered a standard contingency".
And I have no idea where you got the "rationalized as inevitable in hindsight" thing. I've never heard of that in relation to black swan events before.
Have you read the book?
Anticipation is one thing, effective response in the seconds before disaster strikes is quite another thing. This might not have been an absolute black swan, but even with foresight it is challenging in the extreme to avoid risk.
I've been reviewing what coverage I can find of the present event in Nepal/China, in context with Section 5.1, "Comprehensive approach to disaster risk management", of TFA.
It seems that what would be required would be:
- Active surveillance of glacial lake formation.
- Active mitigation of glacial lakes, reducing risk.
- Warning and response infrastructure, procedures, and protocols along the likly flood path.
From video of what I presume are among the worst-hit areas (see: <https://twitterwebviewer.com/?tweet=2092542957060841592>), there appear to have been at best a few seconds of warning. Very robust structures are demolished virtually instantly. Even had people been sheltering within those structures, or headed up-slope above the water flow, either structural integrity would prove insufficient, or response time inadequate to reach a safe elevation above the debris flow. The latter problem is compounded by what appears to be an extraordinarily strong air blast (likely hurricane-strength or greater) as well as massive amounts of airborne debris, much of it rock.
Terrain is severely constrained in the region, and the only buildable regions are in river valleys themselves. The Gyirong Port border crossing is located deep within a river channel, and despite robust construction simply could not survive the event.
See:
<https://en.wikipedia.org/wiki/Gyirong_Port> (Wikipedia article on the port.)
Map / satellite view: <https://www.google.com/maps/@28.2792579,85.3752907,1341m/dat...>
(Take a few minutes to examine the region around the port itself ... there are several communities and businesses all well within the disaster zone, and I suspect that obliteration to those matches or exceeds what was captured on video at the crossing itself.)
From the first video at this Twitter post, a camera situated roughly 20m above the base terrain did not survive the event (though it transmitted for roughly a minute).
A second camera (I believe near the same location) shows similarly catastrophic damage, and no chance for anyone at base level to climb to a safe elevation before being overtaken by the debris flow.
Wikipedia notes "Floodwaters reached settlements as high as 270 feet (80 m) above the river level", citing <https://english.onlinekhabar.com/rasuwa-flood-in-pictures.ht...>.
Climbing that far would require 4--8 minutes for even a highly-fit person. Available response time in the videos I've seen is on the order of 1--2 minutes. Anyone beginning within the debris zone is already walking dead.
As the Cowboy Junkies said:
Anticipation isn't sufficient. Other than entirely abandoning such locations during all periods of high risk, loss of life is likely, and catastrophic property and infrastructure damage inevitable.<https://twitterwebviewer.com/?tweet=2092542957060841592>
When I was researching this morning I found papers related to this kind of risk from at least 2000. Given 20 years there could have been things done I think. And there is a lot of settlement on the tops of the ranges in that area too.. Maybe the roads have to be on the river valley, but not everything else. People living there could have been offered alternative land to move out of the path of it.. monitoring and early warning could have been set up.. at the checkpoint, if it had to be there, there could have been a big evacuation tunnel carved into the hillside, or something.. I guess Nepal doesn't have a lot of resources though. The same thing even happened a year ago in the sample place, but at a smaller size https://www.stimson.org/2025/investigating-an-emerging-clima...