The mechanics of the Nepali flash flood
economist.com83 points by vinni2 11 hours ago
83 points by vinni2 11 hours ago
https://apnews.com/article/climate-change-nepal-tibet-glacie...
CCTV footage is there. Horrific scene. When you see it coming at you it’s already too late.
It's awful to see dozens of people running and knowing they're all gone. It wasn't even close. They were so small compared to that absolute FORCE.
This is true, and, relatedly, is the feeling I have about all of climate change. By the numbers, it won't be close.
Of course, this little preview is itself anthropogenic. This horrific disaster is the thinnest tendril of the monster we have unleashed.
Both figuratively and literally, this experience was the tip of the iceberg. Terrifying. People might think I'm crazy, but I'm choosing my retirement location 100% based on resistance to climate change. Local water, too much humidity for massive fires, too cold for insane heatwaves... you get it.
Which places have you found? I'm in Canada and figured most of the places are going to suffer more rain falling in the next decades.
I have spoken to quite a few real estate agents in Sudbury who mentioned folks are buying property there as a hedge against climate change.
Not unexpectedly, follow real estate prices.
The average value of homes in safe parts of Canada has risen significantly. E.g. Vancouver is devastatingly expensive, while nearby Abbotsford and Richmond are floodplains and reclaimed marsh, respectively, and are cheap. Sometimes uninsurable, but cheap.
The market will price us all out of the safest places and indeed arguably already has. Expect housing values to continue to diverge. A dry hovel is superior to the mightiest of flooded manses, but a home in a dry, safe metropolis, with enough water for all?
Literally invaluable. It will be priced accordingly.
I've seen recommendations for locations near the Great Lakes. Upper peninsula of MI, for example. Plenty of water. A warming climate should actually make the winters there somewhat less harsh.
Wildfire smoke will be the big question there. It's started to be bad for a week or two a year in Minneapolis, and is only worse the closer you are to the boreal forest.
Wildfires only a problem until the overgrowth is burned off. When there's not enough to sustain a large spreading fire, they will stop happening.
Climate change is defined by both wet and dry extremes.
Excess rainfall creates an explosion of brush that during the now annual drought turns to tinder.
canada's forest is growing, not shrinking. the overgrowth will keep growing year over year
True, but disingenuous, as "over" growth implies a normative cap, but climate change just is moving the cap lower. The ceiling is falling: more and more growth, in every biome, counts as overgrowth.
Eventually only desert remains viable, and everything above it, including arability, is locked away forever.
And the failure of basic services like water and power.
Given it took FEMA ten days to get power restored to the super dome, how long will responses be when there are many simultaneous disasters of that size or bigger? With the current admin the answer could be “indefinite”
Honestly there is no safe haven while humans over-consume continue to waste in the chase of excess. We have seen in the last few years all the supposed climate safe areas get hit hard.
https://www.npr.org/2024/10/09/nx-s1-5137024/climate-haven-h...
birth rates are falling off the cliff in all developed nations, most are below replacement rate already
This event has nothing to do with climate change and is pure fear mongering.
This is the same adage used by the Governments with the "think about the children" campaigns, its a distraction. A cop out.
Yeah, the event primarily marked by receding glaciers probably has nothing to do with this glacier that weakened to the point of destroying a village.
This glacier probably melted many times in the past, especially in such a sudden and violent manner.
I'm sure this is in no way anomalous, nor is it something that could predictably result at some point from a warming planet.
I sympathize with the reaction to the hyperbole, but it's not a binary thing. Better to think in terms of marginal increases in occurrence rate, or in a single case marginal increase in progression of an impending event (glaciers were all gonna be gone in a few thousand years anyhow).
Still plenty of room to debate numbers.
I do not know if I would consider stopping the climate change as a solution for all such events.
Watching the video makes you realize how small you are in front of the nature. It feels painful to even watch it but its an eyeopener at the same time. Its a misconception to think that the climate would always remain same, nature is an constantly moving/changing entity. What might be perceived as destruction is also the mechanism how creation of life or life like conditions happened in the first place. Just makes me feel like appreciating the day even more.
Mt St Helens erupted in 1980. The landslide alone was 3.3 billion cubic yards, that traveled 15mi at speeds of up to 155mph, and buried 23 square miles to an average depth of 150ft, and up to 600ft, within 10 minutes.
The blast flattened 230 sq mi of forest in minutes.
540 million tons of ash fell in 9 hours, affecting 22,000 sq mi.
The mudflow (lahar) was this debris mixing with 170 million cubic yards of glacial ice and snow, moving at 80 mph.
People liked to make smart ass comments about people who took photos "and would soon be dead" - "they were miles away, they could have left". For a lot of them? No.
The sheer magnitude of these events is truly unimaginable, even if you "were there" (nearby).
And MSH was barely a 5 on the VEI 0-8 (roughly) logarithmic scale, though you can't map to death toll easily.
Pinatubo in 1991 was a high 6. Krakatoa too. Tambora is the largest we know, in 1815, VEI 7, and is estimated at eighty times more output than MSH, and triggered the "Year Without a Summer" globally (https://en.wikipedia.org/wiki/Year_Without_a_Summer) that pulled down average -global- temperatures by a full degree over the course of a year. It completely disrupted the monsoon season throughout Asia, leading to flash flooding events like this becoming a very regular occurrence.
I think some of these types of stats are the closest terrestrial things we have at the limits of human comprehensibility (probably only eclipsed by "interstellar distances").
Is it correct to say that the video looks far worse than it actually is ?
As in, the dust/mud particles sprayed & floating in the air do not have the force to do harm beyond vision or breathing impairment, similar to the dust from a collapsing building, or the lead shockwave of a nuclear bomb detonation.
Of course, it looks terrible, and certainly somethingbut its not a reason to perish as long as you can stay away from the following water wall and mud current that does strike sometime after.
No, that's not correct.
The length of time between the spray you mention, and the impact of the water wall, is single digit seconds. It doesn't make a difference.
I don't understand why the push so hard on AI and the greenwashing / misleading information about its impact on the natural world.
I haven't yet been able to properly internalize the horror of this scene. Maybe because we're exposed to so many images from disaster and action movies/videogames, I got somewhat desensitized to the "graphics", so to speak. It's like my brain is denial.
At the same time, I know this is real and a tragedy in an unimaginable scale. Every "little walking figure" is a full human being with dreams, fears and a rich life story.
I'm afraid that at one point it will just hit me super hard.
What scares me about climate change is how frequent these “little figures” are getting wrecked.
In Japan we have had these sudden flood events this year, people just die as their cars are washed away.
Never in my life have I considered checking the weather forecast and flood watch warnings almost every time I get in the car but I do this year.
We have really fucked the climate and this is just the beginning.
About 18 years ago, some guy at work was laughing at a video of someone being blown to pieces by an explosive device. People kept walking by his desk and laughing, I suppose because it looked so cartoonish that it felt more like looney tunes than real life.
As an experiment, I showed the same video to my 85-year old grandmother, and she cried out in horror and prayed for the people in the video for a solid hour afterwards.
The drone footage out of Ukraine was like this. Some of it is cartoonish or like watching an action movie or video game.
It's when you recognise the humanity of the individual - for example IR footage of a soldier trying to sleep in a foxhole before a drone drops a grenade. The aftermath starkly reminders you that this was a living person a few moments earlier.
I go around with the general awareness that about 200k people die every day. I know that disasters and tragedies happen around the world on a regular basis. I know that cameras are nearly ubiquitous even in the developing world, so there is a good chance that any sensational event will be recorded and posted on the internet. Armed with these priors it's not a huge surprise or shock to me. It is still impressive, however.
You might want to take an intense media break. I went to 4chan to find more videos of the event, something it's rather good for, and even those guys were largely shocked and flabbergasted at the scale of the carnage and destruction
Tragedy happens every day, this is likely one of those freak events we cannot do anything about. Millions of people die from hunger and malnutrician every year. Perhaps we could focus our energies on that were it not for the media (us by proxy) that prefers the edgier stuff, since we've desensitized ourselves and seek that fix with something new
The CCTV footage was one of the most heartbreaking things I have seen on the internet lately.
It makes me think a bit of the Johnstown flood from 1889:
https://en.wikipedia.org/wiki/Johnstown_Flood#/media/File:Th...
Is there a text of this elsewhere? I'm hard-paywalled (archive.is doesn't seem to capture a copy).
Is Switzerland exposed to similar risk, given the amount of glaciers?
Probably not. Most alpine valleys were carved by glaciers and have a characteristic U-shaped profile. When you get a landslide into a glacial valley, it hits the relatively flat floor and breaks itself apart. The valleys themselves are usually wide enough that they don't dam either. The alps also have significantly less relief than the Himalayas.
The valley where the floods occurred in Nepal has a V-shape, and the peaks around it have much more relief. It's much easier for a large landslide to fill the bottom, creating a dam that can burst, or just continue down the valley without wasting all its energy on a broad flat plain at the bottom. The upper valley immediately below the cliff face that toppled was also a glacial U-shaped valley though, so this speculation might need adjustment as more work is done.
It's worth emphasizing just how much less monitored and dangerous Nepal's mountains are though. The (greater) Himalayas are unlike any other mountain ranges I've ever seen.
Yes, but apparently they monitor the glaciers stability / Temperature closely and evacuate required
And it is at a smaller scale in the Alpes than in Himalayas. Still devastating:
https://www.youtube.com/watch?v=YisdT5AJobk
France is actively draining some of those glacier lakes to prevent them to build up over time.
another good article, without paywall: https://www.theguardian.com/world/2026/aug/27/nepal-tibet-fl...
Really helpful on navigating what happened. https://www.youtube.com/watch?v=9ZvUQ7aoehw
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Need of the hour is AI for climate change.
