Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

wired.com

Post reply on HN
Print view View original

141–150 of 296 posts

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#141

Post by tzs »

cromulent wrote: post #2

A friend of mine who lives in Queensland (Sunshine Coast) was talking about a recent spell of 32° and 100% humidity and how oppressive it was. My understanding is that such weather is not survivable long term [1] without air conditioning. A power failure would be disastrous. [1] https://www.psu.edu/news/research/story/humans-cant-endure-t...

If you've got a well and your well water is always significantly below body temperature one thing that might be worth considering is installing a hand pump. You could then at least draw a bath and sit in the tub to remain cool.

That works by contact with something colder than you. It does not rely on evaporation and so is not affected by high humidity.

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#142

Post by jameshart »

donatj wrote: post #82
jijijijij wrote: post #68

Earlier quoted context omitted.

You do not understand the issue at hand. Whatever you experienced was way less severe, because evaporative cooling obviously was still possible. There is a point where you simply cannot cool yourself passively. That's the point where survival is at risk regardless of health. https://en.wikipedia.org/wiki/Wet-bulb_temperature

Having a rag of cold water on you will cool you regardless of evaporation. It is a thing that is cooler than the environment. The water from our taps at least is a pretty constant like 50°F

So you have a supply of water at 50°F - that’s 10°C (an optimistic temperature in many places). And you are using it to try to maintain a body temperature around 37°C. Let’s assume you do so by transferring heat from your body into the water enough to raise its temperature by 25°C - that’s probably overly optimistic given that it will also be warmed by the environment and the rate of transfer will be reduced as the temperature increases, but it’s a working number.

The specific heat capacity of water is about 4kJ/kg/°C so a liter of that cold water can absorb 100kJ of energy in the process of warming up. Once it’s warmed up it can’t do any more cooling.

Your body, when not working hard, produces about 200W of heat. That’s 200J per second.

So that liter of water can absorb your body’s heat output from about 500 seconds of being alive. That’s a little over eight minutes.

So that means the cooling needs for one human for one day can be met by about 170 liters of cold, 50°F water. That’s about 44 US Gallons.

If, however, that water can evaporate - well, the latent heat capacity of vaporization of water is over 2 thousand kJ per kg.

That’s why the wet bulb temperature matters. If water can’t evaporate, that cold water can’t absorb body heat except by just warming up.

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#143

Post by Qwertious »

chasil wrote: post #111
jijijijij wrote: post #35

Earlier quoted context omitted.

The thing to think about, is how poorly developed, rural places, without ACs or stable grids , are much more likely to experience heat waves with universally fatal wet-bulb temperatures. Places like parts of India or Bangladesh with high population densities, too. Further more, I think, we also need to consider how non-survivable conditions to humans, may play out for other animals we depend on. The cows, chicken, sh…

As opposed to our current icehouse phase, plants have thrived during intense greenhouse periods of global climate. "Earth has been in a greenhouse state for about 85% of its history... Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously." https://en.m.wikipedia.org/wiki/Greenhouse_and_icehouse_Eart...

The earth is 4.5 billion years old. Over those billions of years, the sun has gotten ~40% hotter, which counteracted the reduced atmospheric greenhouse effect. We can't directly compare our current climate to billions of years ago with just atmospheric conditions.

Also, I notice you said "plants have thrived", and not "major staple crops have thrived". Toxic algae bloom has its own sort of natural beauty I guess, but rice and wheat are both temperate crops and won't be able to grow near the equator if it gets much hotter.

Please note that while hotter temps would warm up croplands near the poles, heat is not light and the tropics are so valuable for farming because they receive more light, not because they're hotter.

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#144

Post by LeifCarrotson »

donatj wrote: post #82
jijijijij wrote: post #68

Earlier quoted context omitted.

You do not understand the issue at hand. Whatever you experienced was way less severe, because evaporative cooling obviously was still possible. There is a point where you simply cannot cool yourself passively. That's the point where survival is at risk regardless of health. https://en.wikipedia.org/wiki/Wet-bulb_temperature

Having a rag of cold water on you will cool you regardless of evaporation. It is a thing that is cooler than the environment. The water from our taps at least is a pretty constant like 50°F

Because Minnesota is a cold place. Many of the places where 'wet bulb' events are most likely to happen have only hot water available.

The tap water in Phoenix can exceed 100 degrees, people will fill a bathtub in the morning so their home A/C and evaporation will cool it off by the evening.

Even river water in India or Southeast Asia can exceed 100 degrees. There is no cold water to wet the rag with unless you have a deep well or refrigeration.

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#145

Post by ImHereToVote »

ponector wrote: post #19
seiferteric wrote: post #13

This is why I think we should be seriously considering atmospheric aerosol injection already. Not sure why there aren't more large government funded studies of this.

Who should pay for it? No one really wants to spend money on something like that. People don't want to spend 0.1% of GDP to help survive people in Ukraine and you think they care how hot is there for the people of Australia?

Is there any evidence to support the case that sending more weapons to Ukraine will spare lives?

If so. Shouldn't we prioritize sending weapons to the people of Gaza first, since their casualty numbers are much higher?

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#146

Post by mempko »

thworp wrote: post #126
hackerlight wrote: post #39

Earlier quoted context omitted.

[flagged]

[flagged]

It's not that complex. We found a cheap source of carbon based energy. Growth based economics pushed us to use and exploit the source. This created a lot of pollution. And now the planet is getting a lot warmer.

I think people say 'it's complex' to avoid talking about the obvious solution.

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#147

Post by thworp »

varelse wrote: post #97
jijijijij wrote: post #54

Earlier quoted context omitted.

> an opportunity for many of the people living near the equator to become more prosperous Please tell us, what you have in mind. More economic growth?

Why the burgeoning economic development of full self-driving space needles! Sure, their former homes will be uninhabitable, but imagine how much they'll get selling the land? Why they'll be able to move to Antarctica if that's what it takes! I'm getting a tear in my eye right now over all that profit and shareholder value as we boldly evacuate the planet into the future!

I encourage you to take a crash course in Mooré, go to Burkina Faso and spread the word to the people. "You will not improve your cirumstances, any more prosperity will destroy the planet." I'm sure they will appreciate your wisdom, almost as much as Cubans appreciate their very eco-friendly economic circumstances. Good Luck.

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#149

Post by ImHereToVote »

seiferteric wrote: post #63
infotainment wrote: post #25

Earlier quoted context omitted.

I believe this was the plot of the movie Snowpiercer . I would be a bit worried about accidental side effects; atmospheric alteration on a large scale seems like a dangerous game.

> atmospheric alteration on a large scale seems like a dangerous game. Were already doing that...

Yes, but we are doing the bad kind of alteration. The good kind of alteration is completely untested. /s

Re: Humanity Is Dangerously Pushing Its Ability to Tolerate Heat

#150

Post by olalonde »

JumpCrisscross wrote: post #130
olalonde wrote: post #118

Earlier quoted context omitted.

Yes, of course. There's a reason why people in developing countries are the least concerned about pollution or global warming. It's because economic growth has a much greater positive impact on their lives than an imperceptibly slow warming of the planet.

> reason why people in developing countries are the least concerned about pollution or global warming Hyperbolic discounting?

Do you believe that the economic progress of the last century wasn't worth a 1-2 degrees in temperature rise? Most people, especially those in countries that developed enormously, would not agree. The positive impacts of economic progress so far vastly outweigh the negative impacts of global warming.
Post reply on HN