Wet-bulb temperature • Hacker News Board

Re: Wet-bulb temperature

#111

Post by generic92034 » Mon, Aug 28, 2023, 5:05 PM UTC

jncfhnb wrote: post #104

generic92034 wrote: post #63

Earlier quoted context omitted.

Also, can we all be sure that electricity will be available during such an event?

Heat waves are dangerous. My point is that wet bulb events are not a magical inflection point. The point to take away is that humidity matters in addition to raw temperatures. Not that there is a specific threshold at which things matter or didn’t matter.

I think that point was well understood, by falcolas, to whom I was replying. But your assumption that it is not that hard to cool down seems a bit strong to me.

In some countries electricity becomes unavailable quite regularly, so relying on A/C during a crisis like that might fail. And that is assuming that A/Cs are common (they are not, in large parts of the world).

Cooling yourself down by using water from a tap may also fail, if, in such a situation, everyone in a city tries to do that. You are assuming a very high level of infrastructure and no critical failures.

Re: Wet-bulb temperature

#112

Post by DesiLurker » Mon, Aug 28, 2023, 5:10 PM UTC

jncfhnb wrote: post #33

studmuffin650 wrote: post #2

in my opinion, a lot of folks won't take climate change seriously until it adversely affects their way of life in such a dramatic way that they cannot deny it any longer. A wet bulb event, occuring over multiple hours, would be that signal. Piles of dead bodies from folks who either were misinformed or weren't able to move to safety would be quite the wake up call.

Some people have fantasies about these heatwaves that just decimate all living things. It’s not that simple. It’s not THAT hard to cool down even if you’re incapable of sweating to do so. People aren’t idiots either. Despite imaginations of cultural hubris, people can tell when it’s deathly, disgustingly hot, and do not casually tank it until they die. And even if they did, they’re not idiots. If one person collapses…

True but you should also recognize the world has more than humans. most other species will not be able to survive such even. Second thing is instead of counting how many dead I'd rather count how many man-years of lives reduced. I'd bet with every such event the average life expectancy goes down, especially for old, super young & sickly. so overall impact would be large number of man-years of lives removed from humanity. some will be discovered immediately & some will be found in retrospect.

Also, IMO most of deaths will come from decimation of food crops brought on by climate change induced 'weather randomization'. our world currently is super optimized for supporting 8B people. any one of the optimizations in the chain fail and we wont be able to easily recover. when multiple fail realistically the world economy sill settle into a non-globalized setup. that will support far fewer people than exist today.

Re: Wet-bulb temperature

#113

Post by p1mrx » Mon, Aug 28, 2023, 5:12 PM UTC

zarzavat wrote: post #106

thworp wrote: post #24

Earlier quoted context omitted.

In my experience the issue is not about taking it seriously, I've rarely met someone totally unconcerned in real life. The real issue is what to do about it, how to do it and in what timeframe. With these wet bulb events and the breathless death counts in the media people get the impression that heat waves are bigger killers than cold winters, when it's the opposite (and if you include indirect and long-term deaths b…

A “wet bulb event” is not just a heatwave. A heatwave is a sustained period of high temperatures. You can protect yourself from a heatwave by staying indoors, using a fan, drinking water, etc. A wet bulb event is a period of complete local inhabitability due to the temperature/humidity rising above the threshold where the human body can cool itself by sweating. These events are so far almost unheard of. Anyone who is…

> Anyone who is in the affected area during such an event would only survive if they had air conditioning and uninterrupted power.

Could you survive in a basement?

Re: Wet-bulb temperature

#114

Post by samcheng » Mon, Aug 28, 2023, 5:13 PM UTC

prepend wrote: post #70

samcheng wrote: post #12

If you haven’t read it yet, the first section of Ministry for the Future by Kim Stanley Robinson describes a wet-bulb event in striking detail. The horror of this climate-change catastrophe is what finally triggers a significant global cultural shift around climate change. The passage was vivid enough for me to suggest preparatory measures to my retired parents. I wholeheartedly recommend the book to anyone intereste…

I found that passage pretty disturbing too. But my takeaway was that there aren’t any individual plans you can make unless you plan on hanging out in a body of water breathing through a straw for a few days. What prep did you recommend to your parents? I’m interested for what I can reuse or adapt.

I've recommended an emergency battery system for their house / air conditioner, a reserve stock of water in the house, a "go bag," and an escape plan to the mountains. Longer term, they are realizing that their primary residence risks unhabitability in summer months. I realize they're in a privileged position, though.

Re: Wet-bulb temperature

#115

Post by samcheng » Mon, Aug 28, 2023, 5:21 PM UTC

IKantRead wrote: post #34

samcheng wrote: post #12

If you haven’t read it yet, the first section of Ministry for the Future by Kim Stanley Robinson describes a wet-bulb event in striking detail. The horror of this climate-change catastrophe is what finally triggers a significant global cultural shift around climate change. The passage was vivid enough for me to suggest preparatory measures to my retired parents. I wholeheartedly recommend the book to anyone intereste…

> wet-bulb event It's probably already too late, but I keep seeing people confusing the concept of "web bulb temperature" (all temperatures have a wet bulb temperature, even ones very pleasant for people) with "the human survivable maximum wet bulb". I frequently see people saying things like "when we reach wet bulb temps..", which feels a bit silly. This always feels like talking about a "Kelvin event" or "Kelvin te…

I've used "wet-bulb event" as a shorthand for the scenario where the wet-bulb temperature rises above human survivability. That's why I used "event" instead of "temperature."

Re: Wet-bulb temperature

#116

Post by ChatGTP » Mon, Aug 28, 2023, 5:35 PM UTC

p1mrx wrote: post #113

zarzavat wrote: post #106

Earlier quoted context omitted.

A “wet bulb event” is not just a heatwave. A heatwave is a sustained period of high temperatures. You can protect yourself from a heatwave by staying indoors, using a fan, drinking water, etc. A wet bulb event is a period of complete local inhabitability due to the temperature/humidity rising above the threshold where the human body can cool itself by sweating. These events are so far almost unheard of. Anyone who is…

> Anyone who is in the affected area during such an event would only survive if they had air conditioning and uninterrupted power. Could you survive in a basement?

Or in a river ?

Re: Wet-bulb temperature

#117

Post by kelseyfrog » Mon, Aug 28, 2023, 5:36 PM UTC

abeppu wrote: post #107

kelseyfrog wrote: post #79

Earlier quoted context omitted.

As much as the story centered around central banking machinations, the buried narrative was that a lot of people in power probably have to die. This realization and it's impossibility make the story a tragedy when compared to the real world.

Sorry, why is it an impossibility for people in power to die? I'm not advocating for violence, to be clear, and in the novel KSM seems to take the stance that at some point violence is really counter-productive. But certainly there have been places and periods in which e.g. targeted kidnappings of rich people, assassination attempts on politicians, and terrorist attacks against high-profile targets have all been arou…

TMftF heavily hints and at times outright describes the existence of secretly funded UN blackops missions that target and assassinate people in power with strategic importance. It's been a few months since I read it, but if I can recall, it also described it's connection with ostensibly grassroots eco-activist/terrorists.

Submarine accidents not withstanding, I'm not convinced the UN in our current timeline could be transformed into one that engages in this behavior.

Re: Wet-bulb temperature

#118

Post by ChatGTP » Mon, Aug 28, 2023, 5:38 PM UTC

wonderwonder wrote: post #87

lukevp wrote: post #5

Earlier quoted context omitted.

Temperature and humidity are high enough that you can’t cool off naturally via sweat. I would suspect most people don’t realize that’s even a thing. I’m from Texas, and everyone thinks they’re heat adapted and tries to act macho. A lot of people would just stay outside and keep working, ignoring any warnings they received.

I expect Texas to be the first state to experience a wet bulb event. Its only a matter of time before we get a combination of extreme heat and a massive failure of their power grid. Hundreds of deaths in a single day will lead to... nothing. Same politicians will be voted in and the deaths will just be counted as the price of freedom

People will probably blame “the woke” and of course China and India.

Re: Wet-bulb temperature

#119

Post by NotMichaelBay » Mon, Aug 28, 2023, 5:39 PM UTC

zarzavat wrote: post #106

thworp wrote: post #24

Earlier quoted context omitted.

In my experience the issue is not about taking it seriously, I've rarely met someone totally unconcerned in real life. The real issue is what to do about it, how to do it and in what timeframe. With these wet bulb events and the breathless death counts in the media people get the impression that heat waves are bigger killers than cold winters, when it's the opposite (and if you include indirect and long-term deaths b…

A “wet bulb event” is not just a heatwave. A heatwave is a sustained period of high temperatures. You can protect yourself from a heatwave by staying indoors, using a fan, drinking water, etc. A wet bulb event is a period of complete local inhabitability due to the temperature/humidity rising above the threshold where the human body can cool itself by sweating. These events are so far almost unheard of. Anyone who is…

> Anybody without AC would die

Couldn't you just eat ice to keep cool? Heat from blood transfers to the ice as it melts and warms in the stomach, then it leaves the body completely through urination.

Re: Wet-bulb temperature

#120

Post by JeremyNT » Mon, Aug 28, 2023, 6:01 PM UTC

bradford wrote: post #89

Maybe this is a pet peeve of mine, but I'm annoyed with the use of the term 'wet bulb event' here and elsewhere. Wouldn't it put less burden on the reader to just say "wet bulb 35C"? (That is the temperature that most people seem to be referring to when they say 'wet bulb event'.) Every place on earth has a wet bulb temperature, all of the time. Saying "wet-bulb event" doesn't really help explain the web-bulb tempera…

I feel like the terms in use around this are quite abstract and hard to reason about. I like that the wikipedia article converts this to something more useful to intuit for most of us:

> Even heat-adapted people cannot carry out normal outdoor activities past a wet-bulb temperature of 32 °C (90 °F), equivalent to a heat index of 55 °C (131 °F). A reading of 35 °C (95 °F) – equivalent to a heat index of 71 °C (160 °F) – is considered the theoretical human survivability limit for up to six hours of exposure.

The US NWS, for example, uses heat index commonly. In the US south I seldom see it go much over 110F, and six hours is a long time to be exposed to the elements even at the current levels of heat.

This isn't just a case of hitting some threshold where we all drop dead, but as temperatures rise it will slowly cause people to migrate to more temperate climates and/or seek out better cooling structures (either actively through air conditioning or passively where that isn't an option).