The emergence of heat and humidity too severe for human tolerance (2020) | Hacker News Reader

The emergence of heat and humidity too severe for human tolerance (2020)

advances.sciencemag.org

453 pointsboplicity395 comments

Kim Stanley Robinson's recent book The Ministry For the Future starts with a very disturbing scenario: A heatwave with a "web bulb" temperature of 35 Celsius.

It turns out, in those temperatures, even young and healthy people can't survive. Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die.

It's looking increasingly likely that such heatwaves are possible in the future, and possibly quite deadly. This could result in the mass deaths of many people, especially in poor tropical countries that don't have a stable infrastructure to cool most people during such a heatwave. I hope a mass death event from a "web bulb" 35C heatwave never happens, but I'm losing hope, especially with the increasing global temperatures, and the very lackluster progress being made on carbon output.

> Combined with power outages, as happens in the book, everyone living under such a heat wave will likely die.

That's an exaggeration. Extreme heat (including heat waves that exceed this threshold) happen semi-regularly, and the death rate when they occur is nowhere near 100%. More like 0.1% or less.

Electrically-powered air conditioning is not the only way to cool a human body.

Simply escaping to an underground or substantially enclosed area is sufficient for periods of up to a few days, or even weeks depending on the thickness of the walls. Car parks, cellars, caves, etc... all retain a relatively constant temperature irrespective of temporary swings of the air temperature outside.

Similarly, immersing oneself in a body of water below about 36 C is also sufficient, and that's typically available even if the local air temperature and humidity exceeds safe levels. E.g.: Rivers "carry" the cold down from mountains, and are safe havens during temperature extremes. Even the local pool is sufficient, because water has such a massive thermal capacity that it won't heat up anywhere near as fast as the air around it.

At times like this you see people filling up their bathtubs and just hanging out in there until things blow over.

More worrying is what happens to wildlife. Some animals simply can't escape like humans and most animals can. For example in Australia a recent heatwave killed something like half of all flying foxes!

> Extreme heat (including heat waves that exceed this threshold) happen semi-regularly

The threshold is wet bulb 35 for 7 hours. That is when fit young humans can't survive. Older people die well before that of course.

And no, it doesn't happen regularly. I wasn't aware it had happened at all, although others here say it has. But it has come close. From https://www.telegraph.co.uk/global-health/climate-and-people... :

> Jacobabad crossed the 35C wet bulb threshold in July 1987, then again in June 2005, June 2010 and July 2012. Each time the boundary may have been breached for only a few hours, but a three-day average maximum temperature has been recorded hovering around 34C in June 2010, June 2001 and July 2012.

These people don't have the escapes you mentioned. They are in a city with no running water and no cars, let alone car parks. There is no river, but there are a couple of small lakes.

Here's a discussion of heat index and wet-bulb temps, with records from around the world.

https://www.wunderground.com/blog/weatherhistorian/record-de...

The most dangerous / frequent occurrences seem to be measured in the middle east near shallow gulf coasts. Appleton Wisconsin holds the continental US record, apparently?

This is from 2011.

This looks more updated: https://www.weather.gov/jetstream/hi

and says:

> The highest dew points, and therefore the highest heat indices are usually found near warm bodies of water.

> In the world, the warmest water is found in the Persian Gulf where the water temperature typically reaches up to 90°F (32°C) in summer. Therefore dew points will be that high as well.

> The highest dew point ever recorded, 95°F (35°C), was recorded at Dhahran, Saudi Arabia, on July 8, 2003. With an air temperature of 108°F (42°C) the heat index was 178°F (81°C).

> In the United States, the highest dew point ever recorded, 90°F (32°C), was recorded at the New Orleans Naval Air Station, on July 30, 1987, Melbourne, Florida on July 12, 1987. Heat indices were in the 130's°F (50's°C).

> Appleton, Wisconsin also had a 90°F (32°C) dew point on July 13, 1995 with a heat index of 149°F (65°C)."

So, it happened once, in Saudi Arabia?

Jeez what a hot place... Any idea what geographic features make it so dang hot? It's not too far from water (just looking at a map).

I lived about a hundred miles from Jacobabad in 1987. It was known as the hottest place in the world then along with Sibi to the north. I remember 50C temperatures but it was dry and I used to walk outside to the market around noon. Once my school principal saw me walking without a hat that summer and lectured me about safety but I didn’t feel anything bad. It helped that I was thin and had a high surface are to volume ratio so heat never bothered me. My father worked for Exxon and we had free electricity and every house had massive 8-ton air conditioners, so the heat was never a problem for us.

Sibi is in a hollow formed by some mountain ranges to the north. Perhaps hot winds from the south get trapped there. Not sure about Jacobabad though…could never find any reason why it was so hot.

Another time I was in a car with no AC right after a rainstorm, and it was so hot in the backseat that every time the car stopped the heat became unbearable. When the car was moving we had some wind and it helped.

In Canada I’ve always noticed the temperature can be 5-10 degrees cooler under trees in a forest. Not sure if it’ll be so cool with high humidity but certainly trees will block the sun and trap air cooled by the ground, so they are the best defence against global warming.

What city doesn't have running water?

The city can have running water while some people living there don't. Slums or homeless encampments are common the world over in large cities.

It means some people simply have no means to escape such heat and will likely die.

In the US, they sometimes open cooling centers during heat waves so homeless people and poor people have a place to go. I never went to such but they did that in Fresno and bus rides were free if you said you were going to a cooling center.

Many cities I would think. My spanish teacher lives in a big city in Venezuela and they use water tanks and electricity is rationed.

Lots. Many cities have running water for only a few hours a day.

And there may often be only one tap per 100 people in densely populated slums.

I’m pretty sure Jacobabad has cars.

Some people having cars != everyone having cars.

Wet bulb of 37C does not happen semi-regularly. Table S2 of the article shows a TW of 35+ has only happened 14 times in their ~30 year dataset so I would even hazard a guess that TW of 37 has not yet happened.

These events are usually short (for TW >35, majority only last an hour, see Sup fig 2), which is perhaps why we are not seeing many deaths associated with them.

With regards to immersing oneself in water, a bathtub is good so long as groundwater is available; if everyone starts filling their tubs for every heat wave it might start becoming more scarce. I would have thought natural bodies of water like the sea would have been a good choice, but the authors point out that in one region where wet bulb temps >35 were happening they also observed frequent sea surface temps >35 too (sup fig 16).

There are ways to survive and you have provided good ones, but they won’t be available to all who experience these events if they continue to increase in number. And excellent point about wildlife! That’s a whole additional side of it that will probably get lost in the mitigation effort…

Air is an insulator, 35 degree weather will cause extreme internal temparatures but 35 degree water allows you to transport all your excess energy to the water. 38 or 40 degree water would be deadly, but I wonder what the air temparature is when it gets that far.

Many apartments don't have a bathtub, only a shower. And if everyone keeps tap water running, the pressure will drop down to trickle. Cold cellars can be in short supply, underground car parks tend to get hot too. And seems you probably never bathed in 35°C water, it's definitely not refreshing.

And there are psychological issues that people just don't know what to do till it's too late. I was living an apartment with only 1 southern window, the heat was hard to vent. Once during a heatwave I found myself in a weird lethargy then I started going sick and then I found out the thermometer shows 40°C inside. I went outside immediately. Were not a healthy young man, that could have ended up badly. Since that I never underestimate the heat.

That does not mean 100% fatality rate is possible but it definitely might be more than 0.1%.

> underground car parks tend to get hot too

This is something that has puzzled me every time I park in the underground garage under City Hall in Palo Alto. It is always so hot down there compared to the outside air.

I was about to ask if anyone knows why that is, and then realized I could search for the answer:

https://www.google.com/search?q=why+do+underground+garages+g...

Lots of interesting opinions there, including a previous HN thread.

One discussion I liked showed up when I'm signed into Google but was missing from an incognito search:

https://philip.greenspun.com/blog/2013/07/05/stupid-geophysi...

> Cold cellars can be in short supply

If this starts to happen semi-regularly, you can bet my garden will turn into a little hobbit hill/cellar.

That said, I agree that if it happens suddenly to that extend, we would likely be looking at more than 0.1%.

True. Which is why what always puzzles me is that cities like Austin or Phoenix are gaining population. It's so hot there!

"Many apartments don't have a bathtub, only a shower. And if everyone keeps tap water running, the pressure will drop down to trickle."

People don't have trashcans, storage bins, etc?

"And seems you probably never bathed in 35°C water, it's definitely not refreshing."

Where is this 35C water coming from?

Also, if it's a humid heat, there are likely to be natural or artificial bodies of water around. Hopefully the people have been taking care of them and they aren't a cesspool.

Sure, some people may die, but it should be very low.

Edit: why downvote? All the excuses the previous person gave seem petty to me, so I'm wondering how that person came to their conclusion. Especially for where that hot water is coming from.

Well... people are resourceful. I mean, we may have gotten soft living in civilisation... but we still have some survival instinct. Shade, bathing, burrowing etc.

Still, that factoid is troubling. These are conditions that exceed humans' operating conditions. We're used to that on the cold side. Plenty of people thrive (miserably) in places that get cold.

But, there are actually far fewer good cooling options. Air conditioning is more complicated than heating. You can heat with fire, warm clothes. Even exercise, though this is not sustainable. A sauna is nice, but people don't live in their saunas until temperatures get tolerable.

Also, the heat cutoff is more of a universal. A lot of organisms seem to start failing at temperatures like this.

The human body can generate heat by eating food, it's just a matter of insulation to stay warm. Our bodies can't generate cool at a wet bulb of 35C. That's a huge difference.

How tens of millions people can escape underground or rivers? I think that there will not be space available for most of them.

I don't think space is the issue. Most people live 200 miles from the coast. If that gets as hot as the inland, people will fan out to find whatever shelter they can. While I hope there are cool materials science breakthroughs that can withstand high temperatures, I imagine a lot of people will make homes in caves and underground, like a nuclear bunker.

That would definitely change cultures and economies, but if you can't get out of those places, it might be your only option.

The problem with lots of people in water is that leads to drownings.

"There is a clear connection between heat and drowning. That's when people want to go in or near the water, and the risks of drowning increase," FSL's Executive Director Kristiina Heinonen told Yle in July:

https://yle.fi/uutiset/osasto/news/drowning_deaths_reach_10-...

Well yes, and the problem with lots of people out of the water is that it leads to traffic accidents. Is there a name for this fallacy that proclaims things risky by comparing them to a theoretical situation where everyone is immortal?

There's a difference in that deadly heat can make people who cannot swim, start panic crowding in the water in tens of thousands of people large groups?

Sounds to me like a mostly not seen before thing

> Is there a name

"False analogy" is what comes to my mind, maybe there's something better

Huh. Glad to read what you wrote. I trust you over actual scientists, because you wrote it so well in a short few sentences. Thanks for the info!

Even if they are not that deadly extreme heat waves could crash power grids (which is very costly due to lost productivity), kill crops and livestock, damage infrastructure, cause extreme increases in energy demand, and generally cost a shitload of money.

A higher frequency of extreme cold in winter in areas that are not accustomed to it, like what recently happened in Texas, may also occur with similar consequences.

I don't think climate change will be a catastrophe movie directed by JJ Abrams. I think it will be a gradual process in which we pay back the "loan" of fossil fuel use with interest.

We put our civilization on a credit card without knowing the interest rate.

We could have really slowed down our running up the balance in the 1970s and 1980s with nuclear power, but we didn't. We could still be doing that plus deploying a lot of renewable and storage tech that was not mature back then, but we're doing far too little of that. We are still adding to the card balance and we still don't know the interest or the repayment terms.

If there are feedback loops in the climate system that we trigger, the loan could be an ARM with unscheduled interest rate increases and balloon payments.

Our children get to inherit most of this bill.

The smart thing to do now would be for everyone around to world to start digging underground relief shelters.

Probably everyone painting their roofs white would help too.

And starting with this, (digging, climbing the roof) when it's warm already isn't going to end well

The municipalities in the relevant places ought to advice people to prepare well in advance (and how)

Karachi, and Sindh at large often goes through periods of +35 wet bulb.

People can jump into fountains, or other bodies of water, hide at home, airconned buildings.

In the end, people can try to brave it, and wait for the relatively cool evening.

Wet bulb thermometer is the kind that a pair of thermometers are mounted together with one wrapped in wet cotton and the other dry. Typically between the two glass tubes is a little look up table that gives humidity from current dry bulb temperature and delta between the two.

I don't know what exactly environment reaching 35C/95F web bulb means, but considering 1) it indicates temperature of a thermometer cooled by evaporation, and 2) body temperature of a human is ~40C/100F, I think it means evaporative cooling aka sweating is becoming useless. It won't be a huge stretch to consider that unsurvivable.

Wet bulb 35C is equivalent to a heat index of 160F.

One issue that people who haven't experienced extreme heat might not realize is a lot of people just pass out really quickly. While it takes a while to go past the point of no return and they theoretically could be egressed to somewhere they can cool off and recover, if they're alone, they're not going to.

I understand you are probably American and therefore not used to Celsius but just so you know the body of a human is around 37.7 °C. 40 °C is already life-threatening.

"I think it means evaporative cooling aka sweating is becoming useless. It won't be a huge stretch to consider that unsurvivable."

This assumes there are no alternatives to evaporative cooling via sweat.

Yet people did. The heat stroke at 35C° wet bulb if far from instantaneous.

> It turns out, in those temperatures, even young and healthy people can't survive.

Of note: that’s literal, even doing nothing and sitting in front of a fan you can’t cool down.

And do one of the issues 35 WBT “hides” is that any activity lowers the heat stress threshold. Sugarcane workers are already dying due to heat stress today, and have been for a while. There’s been an “epidemic” of “kidney disease” in central american sugarcane fields for a decade now, with young men showing rates of kidney diseases 15x the norm.

According to Wikipedia[1]:

"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 (130°F). The theoretical limit to human survival for more than a few hours in the shade, even with unlimited water, is 35°C (95°F) – theoretically equivalent to a heat index of 70°C (160°F), though the heat index does not go that high."

So the practical limit is indeed much lower than 35°C; that's the limit at which you're basically going to fall over and die.

[1]: https://en.wikipedia.org/wiki/Wet-bulb_temperature

And people START dying, en masse, at 28C wet bulb (see chicago and vancouver heat waves)

> en masse

I'm not sure that phrase means what you think it means... Yes, there were ~600 tragic deaths in BC from the heat dome, but en masse means 'as a whole' or 'as a group', and a .012% death rate does not really qualify there.

If you understand French you'd know it just means in large quantities.

At that heat, counterintuitively, sitting in front of a fan will only heat you up faster.

i probably have a comment somewhere recently, but singapore is already in WBT >35 conditions in the day. it eases to around 30 at night or when rain falls.

as long as power is running, it's actually fine in this country, but that's because we've designed our living space around the heat. it is entirely possible to never be exposed to the sun in a normal day in the life of a working resident here if you stay in the right neighbourhood, and this includes the daily commute, hobbies, physical activity, going out for drinks etc.

more and more of the country is being built underground and more and more of our air is becoming conditioned. this is the arcology of the future and it is somewhat pleasant.

edit: actually i think our infrastructure was built around protecting us from the harsh and unpredictable tropical thunderstorms and the protection from heat turned out to be a nice bonus.

Having lived in Singapore for five years (2012-2017) (and worked out in the field for about 50% of that time) I can say that Singapore is one of the milder places to live. It never ever gets particularly hot (I genuinely can't recall a 100+ degree day in the entire time I was there), and the humidity, while, "sticky" is never really extreme. The thing that gets to you is that the climate never seems to change (with the exception of a lot of rain) - it's always pretty humid and in the high 70s/low 80s, 24x7x365.

Once you acclimate to it though - it's fine - I used to do a 5 mile run every day from Anson Road/GardensByTheBay/MBS - wasn't an issue.

I worked in Dubai for about 6 months, and there were days there that I honestly thought I might die if I didn't get somewhere cool. And it wasn't the days that were 115 degrees Fahrenheit (46 Celsius) (though those were intense) - but the 100-105 degrees at super high humidity that would knock you on your back. Your entire body would be instantly bathed in sweat and it wouldn't help.

I was fine without Air Conditioning in Singapore - would sometimes turn mine off and just open the windows, but I can imagine anyone doing that in Dubai during the hot season.

> I can say that Singapore is one of the milder places to live. It never ever gets particularly hot

Singapore is almost exactly on the equator. UV readings get up to 11 each day (extreme), whereas the most I ever saw in say SF was 5.

Your experience is one experience, mine is that it's a sauna every day of the year. I've experienced extremely hot days in terms of subjective experience of WBT as explained in article. My gf, a local here, also decries the heat. I personally cannot go running before 5:30pm. I got a major sunburn on my back at 5:30pm the time I tried running shirtless at east coast park. Granted, I am pale.

https://data.gov.sg/dataset/wet-bulb-temperature-hourly?view...

The Changi airport weather station does not have any recordings of a 35C wet bulb temperature. And this paper suggests that it is a very uncommon occurrence as yet. What source are you using?

https://www.wbgt.sg/allstations

Yes, I sometimes feel like I'm at death's door when jogging outdoors. Myself and some Westerners I know haven't "adapted", even after years being here. The strategy is just always have ice water in hand if outdoors for prolonged time. I sometimes get laughed at for not adjusting to the heat, but I think it's just too much for some genetic lineages from outside tropics.

Unfortunately a large percentage of folks in HDB flats don't have AC, so I do fear for many citizens in Singapore. With global warming trends it should simply be a free or heavily subsidized utility here.

After a car accident, I had to depend on public transport in the boondocks where my job required shuttling from site to site in very humid hot tropical weather. I thought I was going to die that first week.

One of the locals finally told me I couldnt just walk out of airconditioned low humidity offices into the street and roam around, without giving my body 10-15 minutes to recalibrate. So before setting out from air conditioned buildings, I would stand outside in the shade for a bit and then head out. And that made a big difference. I started sweating less and didnt feel humidity as much.

I've been thinking about this, and it's seeming like childhood exposure to prolonged heat and humidity may be what gives you the ability to handle it as an adult.

It's just an anecdote, of course, but there are notable examples of people i think should be from genetic backgrounds that could handle the heat that can't, and vice versa.

I used to work construction and when I was a teenager I worked on farms growing up in the rural South.

If you work outside all day you adapt very quickly to it. During the adjustment period you are chugging water all the time but you eventually adjust. It's a circulation adaptation that's been observed with special forces recruits.

I'm in Denmark, when it gets 26 degrees here I drench my shirts in ice water and put in the freezer for a bit and then put on to cool down. I'm guessing, given what a wimp I am about the temperature, a few more degrees and I'm one of the first to die.

When you use AC during nighttime you never get adapted to the heat. Try slowly phasing it out.

Big factor is body fat, when I was very skinny I could take higher temperatures than 40pounds later. It made basically 5 celsius degrees difference of "quite nice and warm" vs "too hot to operate" temperature.

Lack of sun exposure can cause hypovitaminosis D, which is a known risk factor for COVID-19 and other infectious diseases. It also impacts nitric oxide production which is a factor in cardiovascular system health. Supplements can mitigate the problems to an extent but are inferior to natural sun exposure.

And before anyone brings up skin cancer, there is no reliable evidence that brief daily sun exposure increases all cause mortality.

> Supplements can mitigate the problems to an extent but are inferior to natural sun exposure.

I've never heard of such a claim, and that seems unintuitive. Why would that be? Do you have a source you could direct me to to learn more about this?

> Supplements can mitigate the problems to an extent but are inferior to natural sun exposure.

Inferior how?

Little pedantic, but you meant "Wet-bulb" temperature (https://en.wikipedia.org/wiki/Wet-bulb_temperature#Temperatu...).

I only know from owning a swamp cooler.

It is worth correcting, because I think most people haven't heard of wet-bulb, just as the methods and formulas that give us humidex "feels-like" temperatures aren't common knowledge.

A lot of ways we measure and describe the human experience of humidity and temperature are not standardized from location to location, so the non-local methods and terminology can be arcane for anyone who isn't a meteorologist.

I never heard of wet-bulb temp until carrot weather included it in a recent update.

Yes, that's right. I did mean wet-bulb. Not sure why my brain didn't register this mistake when I wrote it.

Isn't it basically the same as the dew point temperature? I believe a lot more people are familiar with that.

No, dew point is the temperature of an object on which air will start to condensate (because cooling the given air to the dew point lets relative humidity rise above 100 %, i.e. condensation). Wet-bulb temperature is the lowest temperature an object can reach through evaporative cooling (i.e. humans).

The two are the same only if relative humidity is 100 %: 100 % relative humidity means that if the air cools at all, it will condensate; so the air temperature is the dew point. 100 % relative humidity also means that water cannot evaporate, as the air is already saturated with water, so the wet bulb temperature is also the same as the air temperature.

But that's the same isn't it, because condensation is a reversible process, as evaporation. At some point they will balance, and this is the dew point.

Just looking at the graphs, dew point temperature tends to be a bit lower than the wet bulb temperature (when humidity is equal).

I find it amusing that people are trying to downplay this because it is feasibly survivable in their opinions. If you're wondering "how I can survive these circumstances in my own home?" things are already really, really bad.

95 Fahrenheit is actually quite survivable. It is dangerous for old people, young people, and the very sick when combined with sun exposure and other factors.

I spent much of my life living in that temperature range without A/C, working outside during the day in the sun.

It's hot but not going to kill you. In fact, there are massive homeless encampments outside my window right now in extremely humid, hot, Texas weather (it is 95-97 all week and very human). The homeless have endured many summers like this.

It is a massive stretch to say these temperatures are not survivable. They are not healthy in the long run - but neither is sun exposure.

It's an incredible exaggeration to say Chicago (where 600 people died in the heat wave) is not survivable at all when millions actually did survive the heat wave without AC.

35 wet-bulb temperature is not survivable. That is not a matter of opinion, it is a fact. Your body generates heat and at that temperature it is unable to shed it through any means and you will die in a couple of hours.

If a major city has such a heatwave, it will almost certainly be a mass casualty event, mitigated only by the duration of the wave and how many people have A/C (or how long the blackouts last).

A fan won't work because your sweat will not evaporate: in fact it just heats you up faster (like breathing on your skin in a sauna).

Such temperatures have only been measured a few times on earth, so no, you have not experienced them.

N.B. the 35c/95f temperature they're talking about is _not_ air temperature. It's 'wet bulb' temperature, or what the air temperature would be at 100% humidity. Only when the actual humidity is 100% are the two equivalent. Otherwise, the wet-bulb temperature measures the lowest temperature achievable by evaporative cooling. The survivability concerns of sweat being unable to cool humans below hyperthermic levels should be obvious.

At quick check, humidity in Houston is like 55%, so the wet-bulb temperature is only ~80f. Uncomfortably hot, but not close to the threshold discussed in TFA.

Good to know. I should not have skimmed the article before replying.

They're talking about wet bulb 95 degrees which occurs at somewhere around 130 degrees of open air temperature. You have not spent much of your life at wet bulb 95 degrees.

95F in dry air is not the same thing as wet bulb 95F. That is the majority of the discussion being had in other threads.

Critically, not just 'dry air' vs 'humid' in the human sense. Wet-bulb is temperature at 100% relative humidity. A 'humid' day in the human sense is like 60-70%.

For people reading "web bulb" here and not having the least idea of what it is, first of all it's "wet bulb", and this article explained it very clearly to me:

https://www.iflscience.com/environment/why-is-everybody-talk...

Seems like Wet Bulb is a more precise version of what some weather reporters call "Heat Index". Meant to measure how hot it actually feels on the skin. Is there any sort of formula mapping heat + humidity to wet bulb?

https://www.omnicalculator.com/physics/wet-bulb

In Canada we call it "humidex" because we're cool like that.

Genuine question: does old-style insulation not help? From when I was a kid I remember that a log house built using 60ies village technology (realistically probably more like 19th century technology), insulated with something stuffed in the triangles between logs and wallpaper and logs and planks (and partially eaten by mice ;)), stayed pleasantly cool on 90-degree days. And the dugout under it that we used to store potatoes and stuff like that was actually cold.

In a recent Seattle heatwave, when it was 107 outside my much poorer insulated semi-basement with direct sun shining into its large-ish windows, stayed under 85 without AC.

Couldn't people just build better / underground housing using relatively primitive technology?

Eventually it'll be hot enough outside that the "cooler" inside is not cool enough without air conditioning.

This is temperature of air (big amplitude) vs temperature of ground X meters undergrounds. If you go deep enough it doesn't matter how hot it is outside - the temperature is basically constant the whole year.

http://www.rynekinstalacyjny.pl/images/photos/24/3877/__b_An...

I'd bet that data is from sensors with low heat dissipation. Unfortuantely, humans produce ~100W of heat each. If you're using a small underground basement as a place to escape lethal heat aboveground, or even a large underground basement with high people/m³, this added heat will steadily increase the basement's wall temperature.

The rate of temperature increase depends on physical properties of the basement walls: using the first equation here[0] as an approximation, set x to 0, set q"_o to 100W*(# people)/(basement surface area). α is the thermal diffusivity of the wall material [1].

[0] https://slideplayer.com/slide/1676039/7/images/9/Semi-Infini... [1] https://en.wikipedia.org/wiki/Thermal_diffusivity

We already see 35c wet bulb temps in parts of India. It's deadly.

A lot of new technology could potentially solve this problem.

There are certain types of roofs being installed called cool roofs that reflect heat and don’t absorb it that keeps the inside of building a little cooler.

For people who can afford new technology. For hundreds of millions to billions of people that's not an option.

Radiative cooling roofs, like those from sky cool systems actually cool your house during the day. I'm not sure how cost effective those are but the technology seems to be very promising.

Those radiate through the atmospheric microwave window, right?

Also air conditioning

Imagine a future where looters drive through wastelands where heat waves killed off the entire human population, dead bodies rotting in the street, and the looters rummaging through whatever valuables they find, exchanging occasional gunfire with a survivor or rival clans.

That’s the climate changed world.

Small questions, Arab countries used to build cooling towers a few centuries ago. Would that help for countries you were thinking of?

I started reading it and it’s the most grabbing and realistic writing on climate collapse that I’ve encountered to date.

The prediction of how people react to the changes - from individuals to institutions to governments is spot on.

Highly recommended.

I challenge anyone to read that chapter and not be moved. Absolutely brutal, visceral writing.

> everyone living under such a heat wave will likely die.

I mean ground and buildings have thermal inertia, if the heatwave is relatively short you can survive in basements or underground parking. Also water in the pipes will still be colder than the air most likely.

If there’s a heat wave and drought the only way is to dig tunnels and build cities underground. Water can be imported from the ocean (rising sea levels) and desalinated using solar/thermal power above ground and feed an aquifer!

What is actually going to happen is displacement. The hundreds of millions of people most vulnerable to the consequences of climate change don't have much choice but to start walking. The 2015 refugee crisis in Europe was nothing compared to that, never mind the tiny trivial inconvenience that is current illegal immigration across the Mexico–US border.

Agreed. Europe struggled to relocate 2.5M of refugees over several years.

What happens when people from India, the middle east, ... are forced to relocate? I expect some kind of conflict/war of expansion and probably famine since a lot of the land will be abandoned and hence become unproductive.

On a purely technical basis that may seem reasonable.

On a "we're talking about human beings here" basis what do you do about all the people who feel that the selection and admission process was corrupt and that they've been robbed of their chance at safety? Do you expect them to meekly acquiesce?

I imagine once the first big wave where a nation hits the wetbulb temperature and there is a mass die off you will see panic in surrounding nations and they will scramble to a border. What will nations do with millions of people knocking at the fence wanting in? Uncertain times for sure.

"The study — published in the British journal The Lancet — analyzed data on more than 74 million deaths in 13 countries between 1985 and 2012. Of those, 5.4 million deaths were related to cold, while 311,000 were related to heat."

Study: Cold kills 20 times more people than heat https://www.usatoday.com/story/weather/2015/05/20/cold-weath...

People are unlikely to start a mass migration from traditionally cold climates, but it is very likely that a mass migration will start when densely populated regions become lethal a couple of times a year.

Do you think that having more extreme weather events will reduce the number of weather related deaths, or increase them?

Deaths from natural disasters are at or near civilizational all time lows on a fractional basis of the population, see quote below. This trend in lower deaths should continue. It is not clear to me that we are experiencing more extreme weather events than 100 years ago. We haven't had anything like the Dust Bowl (1930s) or the Great Chinese Famine that killed 45 million (https://alphahistory.com/chineserevolution/great-chinese-fam...) or the Chinese Famine of 1907 that killed 25 million (https://www.bartleby.com/essay/The-Deadly-Famine-And-The-190...). Or the Bengal famine or the Vietnamese famine of the 40s. Or the Yangtze flood of 1931 that killed 2 million. Or the Bhola cyclone of 1970 that killed 500K (https://en.m.wikipedia.org/wiki/1970_Bhola_cyclone)

"What we see is that in the early-to-mid 20th century, the annual death toll from disasters was high, often reaching over one million per year. In recent decades we have seen a substantial decline in deaths. In most years fewer than 20,000 die (and in the most recent decade, this has often been less than 10,000). Even in peak years with high-impact events, the death toll has not exceeded 500,000 since the mid-1960s.

This decline is even more impressive when we consider the rate of population growth over this period. When we correct for population – showing this data in terms of death rates (measured per 100,000 people) – we see an even greater decline over the past century. This chart can be viewed here."

https://ourworldindata.org/natural-disasters

I wonder if going underground can help (being realistic that we are not going to make any drastic CO2 related changes)

I wonder how practical it would be to sink 30 foot deep concrete tube shelters with a ladder and a lid. They could serve as emergency daytime shelters and someone could climb out at night to search for a location with working power or cooler weather.

There'll be issues keeping that cool and the air fresh putting enough people into them. Also some of the most endangered places have huge populations that would make sinking enough shelters difficult. Depending on the soil composition that might be a short term solution too. The soil surrounding the London Underground is particularly bad for this and it's estimated that 80% of the heat ever generated in the Underground is still there in the walls.

https://www.youtube.com/watch?v=hQo6_GkITe0

If mankind has to start living at night because daytime is too hot, at least night owls will no longer have to shorten their life expectancy to fit into a daytime schedule.

Welcome to Spain.

I do wonder, if wet bulb temperature is a function of temperature and humidity (assuming reducing temperature requires electricity usually) will the real trick to reduce mortality will be to reduce relative humidity in a confined space. A supply of emergency desiccants somewhere at home may be an avenue worth exploring.

This was the original application of Air Conditioning: to reduce the humidity of air inside a building.

I suppose the best available option for a lot of people if designated shelters aren't available would just be to walk to the nearest body of water and climb in, and wade around until the heat subsides.

You're assuming the nearest body of water is somehow cool enough, which is often not the case.

itd make more sense to lay a bunch of pipe underground and cycle air through it. or water in a closed circuit with a heat sink.

If you have power you can just use a heat pump like a window unit. This is about places with unreliable or negligible power grid.

Not practical on any Pacific island sitting just above sea level.

Sit in the water instead? The ocean water tends to be cooler than the air due to oceanic currents.

If the water is still running - can't people spend a lot of time in the bathtub?

In the locations this happens, does everyone : have access to a bath (one per family member), running water (in a city were everyone is running a bath at the same time), a job where the aren't forced to go out and work every day to survive?

It only works if the water is cooler than the ambient air. A bathtub full of water will warm up to ambient at some point and won't be as effective after that.

What will the vegetation and animal life look after such a heat wave? Mad Max desert?

Or are they so much better adapted that it won’t be a problem (I don’t think so)

It’s not just about adaption, many animals in hot climates burrow which provides a cooler place to rest than above ground housing.

As an aside, would you recommend that book?

Yes... But the first chapter the OP is talking about is truly horrifying, I honestly wish I hadn't read it. His other book New York 2041 also deals with climate change and is less traumatizing.

Yeah, there's so much unavoidable negativity around, so when I have the chance to choose I'd rather focus on positive things and read/consume things that make me happier instead of depressed.

Especially in terms of climate change. I try to live as green as I can and I vote for a climate focused party, other than that there's not much I can do as an individual. Reading about how bad things may become doesn't help me one bit.

I made the mistake of starting to read this before going to sleep last night. Terrifying.

oh OK, so no one will do anything about it and it's probably gonna happen and when it does it will be. out of the news cycle in a few days. noted.

This feels like one of those prescient HN comments that are cited in the future. IDK, just... replying to say I was a witness too.

Wet.

It’s called wet bulb, not “web bulb”.

A mass death event will likely happen in a city with 26 million people that most folks outside China aren’t aware of the danger..Shanghai. Shanghai has been having extreme heatwaves, the worst one in 2017 where the temperature went to 46 degrees. Shanghai is projected to be unlivable in this century.

I’m not sure if it’s an issue specifically around Shanghai, but electric power has been unsteady in China at large. An energy crisis during a heatwave could be indeed deadly, especially with the ambient temperatures of city life. I’m bullish on Chinese acumen for major infrastructure projects and I’m sure they will adapt, but that seems like a crazy costly set of projects. At this point ultrawhite paints look promising.

> especially in poor tropical countries that don't have a stable infrastructure to cool most people during such a heatwave

Like California? They already can’t keep the lights on with rolling blackouts happening every year. If one of those blackouts happens during a severe heatwave, it could be serious. Not to mention the serious economic cost of having a third-world quality grid in what should be one of the union’s most prosperous states.

I think California's air is too dry to get to the wet-bulb temp limit.

For now. I was seeing temps pretty close to 120 last year. It was dry, but who knows how the climate will change either the humidity or the high temps. 130+ doesn’t seem inconceivable and that gets pretty close to the limit.

I have travelled to two countries where heat can hit that temperature, and they do not have the luxury of any AC, or in some cases even a fridge.

A few cities around the world do reach 35 or higher regularly during summer. And in a some of those people have lived for thousands of years.

https://en.wikipedia.org/wiki/List_of_cities_by_average_temp...

Wet bulb temperature is not the same as average temperature. See https://en.m.wikipedia.org/wiki/Wet-bulb_temperature

Here is a decent visual explanation of the relationship with relative humidity: https://digitalcommons.unl.edu/cgi/viewcontent.cgi?referer=&...

Edit: didn't know about wet-bulb temperatures (was confusing it with perceived temperature). Here is a link for a wet-bulb temp. map: https://meteologix.com/th/observations/701-e-263-n/wet-bulb-...

I think you don't understand what wet bulb temperature is.

Wet bulb temperature is a combination of humidity and temperature.

Wet bulb temperature of 35C means your body physically cannot get rid of heat and you WILL die, rather quickly, even in shade. There is no escape unless you have ability to control humidity (ie. remove some humidity from the air).

Up until recently we did not have situations on earth where wet bulb temperature would reach 35C. Even in the most hot places the air would be dry enough to bring wet bulb temperature down under 35C meaning, things can cool below human body temperature.

The issue is that a lot of people in hot places simply do not have the means to control their climate in their houses, assuming they have any.

I think we know based on the science we’re not going to see a stabilization in temperatures for at least 30 years under the best scenarios. We should focus on ways to save these lives. Solar powered swamp coolers is what is I’m thinking about. They require water however and that’s going to be as big of a problem as heat. Already is in many places.

Swamp coolers cool based on evaporative cooling: water evaporating into dry air reduces the (dry bulb) temperature of the air. So with high wet bulb temperatures indicating air is already saturated with moisture, the swamp cooler won't work.

Dehumidifiers are a thing. I presume that having water and electricity is a bigger problem for most people, but I’d love to be educated more on the problem, if you have links or literature.

Swamp coolers do not work in high humidity. Running cool water from underground over oneself works, but is unsustainable and impractical. Going underground to someplace cool is also sometimes an option that does not require electricity, but is often impractical and highly situational.

Ultimately all that really works in our modern world at scale in such a heat wave is powered air conditioning, so ensuring that electrical power is not interrupted during such an event is of paramount importance if we are to avoid this new sort of natural disaster.

You could potentially heat up a dessicant to dry it out and use that indoors to survive the humidity without having to go underground or have AC.

Migration. Large parts of the taiga and permafrost are about to open up to human habitation. All the folks in the Middle East and India should move north in search of better weather.

Human societies have been historically very bad at handling large scale migrations, but it's about to become necessary.

Apart from all the other issues (societal, etc) with that the climate of Yakutsk[1] can give an indication of how hospitable that region is. Spoiler: It’s temperature span is over 100C (nearly 200F). Brutal winters, brutal summers.

Not saying you’re wrong, though..

[1] https://en.m.wikipedia.org/wiki/Yakutsk

there was an article during the recent Oregon heat wave by someone who moved to the PNW as a hedge against climate change. that heat wave killed almost 200 people and is estimated to have killed a billion marine animals.

https://www.theguardian.com/us-news/2021/jul/08/pacific-nort...

https://www.theguardian.com/environment/2021/jul/08/heat-dom...

Migration is not going to cut it. Climate change is making weather more chaotic and unpredictable. Escape is impossible. The only place you can go where the planetary weather system’s disintegration does not pose a danger is space, where the absence of that same disintegrating weather system makes survival even harder.

Reversal is the only option.

I am sure this will cause no serious issues whatsoever.

Or.. Build more basements and underground shelters.

No, it wouldnt work as the heat would have nowhere to go. And the mid east people didn't do it - https://en.m.wikipedia.org/wiki/Windcatcher

Instead you build and live in highrise/towers - that gives cheap ventilation which is a half the solution.

And I liked the siesta and the following it very active life till deep night in Spain - another natural adaptation to hot climate. It makes for much calmer and steady life rhythm and feeling.

There are two cities in India that are pretty close by where this difference is very clear. Chennai is on the coast, while Bangalore is inland at a higher altitude while they’re both pretty much the same latitude.

The difference in perception even if the dry bulb temperature is the same is insane. In Bangalore I can always find shade and it’ll be cool instantly, but in Chennai my whole body is always soaking wet, my clothes are drenched with my own sweat and I still feel like always about to faint.

I used to take long walks during the day when I lived in Bangalore (it has other man made problems like traffic which are still irritating) but here I Chennai I can’t walk or jog outside even if I wanted to. I step outside only to run to the car and turn the AC on.

It's striking to me that according to the map in figure 4, the parts of the Indian subcontinent most at risk are in the Indus and Ganges valleys. Areas hundreds of miles further south (including Chennai and Bangalore) are safe!

Why is this? I see that the south is much more mountainous [1], whereas the Indus and Ganges valleys are very flat (hence that term "Indo-Gangetic Plain"). Is it just the combination of being low-altitude, being inland, and having lots of water? Or are there also differences in prevailing wind, or something else?

[1] https://www.reddit.com/r/MapPorn/comments/jcdtvi/relief_map_...

The seabreeze colliding with the mountains in South India likely results in significant cloud cover, which cools the surface by reflecting sunlight. You can see here that the southern region has less total sunlight per year (lighter = cloudier):

https://en.wikipedia.org/wiki/Sunshine_duration#/media/File:...

The article indicates that in tropical regions cloud cover has an impact on maximum temperature reached; subtropical regions have less consistent cloud and so have stronger heatwaves.

Similar question to this that I've been wondering this wildfire season -- at what point is AQI (Air Quality Index) too severe for human tolerance? The scale tops out at 500, what happens to a person if the air is even worse than that?

Some sensors near Medford, OR are reading in the upper 400's and even low 500's -- what happens if it hits what would be the 1000's if the scale went that high?

I'm mostly thinking of particulates, but AQI includes other gases like CO, SO2, NO2 so maybe those would be more dangerous than particulates (and certainly harder to filter out)

Practically speaking, you start wearing a mask. You start filtering the air inside, and you stop going outside. This way-of-life is already familiar to people in certain major cities, and to those with health issues that make them more vulnerable to air quality problems. It's a worse life, but it's still life.

This is one reason I hope it continues to be socially acceptable in the U.S. to wear masks. I've wanted to wear one even pre-covid for pollution and pollen, but you would get very weird looks, or even stopped by security in some cases.

I still wear mine. Recently visited family who live in $RED_VOTER area. Got a bunch of looks from the locals. Nobody said anything - and who cares if they did? I've learned to say "fuck off" in multiple languages (thank you internet!)

Just tell them it's to protect your face from CCTV facial recognition. Most of the non authoritarian right is for that.

“I have an immune disease you asshole.”

Medford resident here. We experienced a few days of 900+ last summer.

It's very bad. Even in the 400's, it feels like chain smoking. At 900 the air is thick enough to block out most of sun. I have no idea what this has done to my health, but I guarantee it's not good.

Wow. It hit 140 where I live and I immediately ran to the hardware store to buy better AC filters, and more air purifiers. How are you handling it in a practical sense?

Practically speaking... I guess you get used it. Yesterday I spent the afternoon outside by a river in 200+ AQI, and it didn't seem too bad. I use an N95 mask if it's bothering me, and a respirator if I have a lot of work to do outside.

The main issue for me so far has been psychological. Summer used to be peak season here, with tons of amazing nature and outdoor activities. Now, it's just a waiting game until the rain starts back up again.

The loss of place is palpable, honestly. My niece and nephew have never gotten to experience a normal summer: https://imgur.com/a/EAVStxe

Edit: This graph cuts off at 2018, but believe me when I say that 2019, 2020, and 2021 have been even worse.

I’m speaking out of my depth here but I believe exposure related disease is based on the particle density over time. Particles can clog the respiratory system, reducing blood oxygen and introducing free radicals. To a large extent the body is able to remove the debris, but if there is too much buildup due to prolonged exposure to high AQI then it can be difficult to recover without intervention.

I was at a chain drug store the other day and saw a display for canned oxygen, regular and Peppermint flavor!?! It seemed like another sign of the apocalypse to me, but maybe just a gimmick or stopgap for terrible air quality events.

Sounds like oxygen bars at home.

https://en.wikipedia.org/wiki/Oxygen_bar

There are a bunch of cities in China and India where AQI peaks at well over 1000. As you'd expect, the long-term health effects are similar to chain smoking, but it doesn't cause healthy people to drop dead on the spot or anything. Asthmatics, on the hand, are in for a bad time.

I think it was high 500's here (Nevada City) a last week. I wore a mask for the short period I had to go outdoors.

Ideally, you'd want a VOC filter along with a HEPA filter.

It's a hostile environment - so is a blizzard. That's not saying it's not a problem but humans are able to survive a lot.

We had over 500 here in Bend, Oregon thanks to numerous wildfires to the west of us, last September: https://www.opb.org/article/2020/09/15/oregons-air-is-so-haz...

It was an awful time. Couldn't be outside because of the air, couldn't have guests over because of the pandemic.

One of the previous years AQI 246 (in SF) was compared to smoking 11 cigarettes a day by some researchers. Assuming you do literally nothing to avoid it, 500 must be like smoking a ~pack a day. That is a typical, easy to track volume for many smokers; I used to smoke a pack a day for a couple years (gave up completely ~15 years ago)... it's not great statistically (and certainly make cardio harder from my experience), but it feels just like normal life and is low enough impact that many people never give up 0_o

Well it already happens when big wildfires happen and people have dangerous air around for days. In the short term, keeping everything closed and using masks is probably enough.

If you mean as a permanent thing, you'd need houses to start having filters on air intake and no openable windows, with instead all air being circulated by the place that has a filter

Due to local geography trapping wildfire smoke, last week SLC, UT, USA hit over 200 and even walking to the mailbox without a mask on was uncomfortable. My friends were wearing N95s and respirators when walking to their cars and using the recirculation setting. My HVAC filter was dark with smoke particles.

Anything over 100 and I'm feeling uncomfortable. Practically speaking what happens is you stay inside and get good air filters if you have to go outside.

I wonder if people confuse wet bulb and dry bulb here. Wet bulb is related to how well your air conditioner or sweating will cool you. Dry bulb is what we usually say when taking a temperature reading, or listening to the local news' meteorologist.

Wet bulb temperature doesn’t have anything to do with air conditioning, unless you’re only talking about evaporative coolers.

Fair. Cooling towers in commercial HVAC use evaporative cooling. Residential cooling doesn't, but still has to exchange heat to a system above the load it common transfers. I think it may be worse in these situations, but I am not sure.

Sure, but the water in commercial AC is just to cool the compressor coils. It still uses a phase change system like any other AC, so it’s not limited by the wet bulb temperature (although the warmer the ambient temperature is, the less efficient it is).

What is the efficiency rate at 35°C Wetbulb?

Ya, for messaging, "wet bulb" doesn't work well. We need a more intuitive phrase, like a "wind chill factor" for heat + humidity = danger.

Edit: chewing on "wet heat factor". What do you think? Cliches like "but it's a 'dry heat' harhar" are already common. So "wet heat" might click.

IMO wet bulb is much more intuitive. The parameters for heat index are subjective.

I believe the intuition depends on context. In common jargon Wet Bulb isn't widely understood!

https://www.weather.gov/ama/heatindex

Nice, thanks. FWIW, I just checked, and wunderground reports both temp and 'feels like', apparently matching the NWS Heat Index:

https://www.wunderground.com/hourly/us/tx/dallas

The problem is that wet-bulb temperature is not the Heat Index or a "feels-like" temperature. Here's a bit more info: https://www.weather.gov/source/zhu/ZHU_Training_Page/definit...

We should call them exterminating heat events, make it clearer.

Love the people calling for air conditioning. They should make peace corp or something compulsory, the degree of out-of-toucedness on some people about the degree of infra and poverty that exists here is extraordinary.

> Our survey of the climate record from station data reveals many global TW exceedances of 31° and 33°C and two stations that have already reported multiple daily maximum TW values above 35°C.

I only did a quick skim of the paper, but I couldn't actually find which two stations they were talking about. I'm curious as to which two places they were.

Jacobabad - Pakistan, Ras al Khaimah - United Arab Emirates, and Jeddah - Saudi Arabia are the only cities with multiple TW>=35 recordings according to their table S2 in page 24 of this pdf https://advances.sciencemag.org/content/suppl/2020/05/04/6.1...

I see a lot of uninformed people on this thread thinking 35C wet bulb temperature isn't such a big deal and proposing various ineffective tips to cool down.

Let me explain what the issue is, in simple words:

WET BULB TEMPERATURE IS NOT TEMPERATURE YOU SEE ON A THERMOMETER. (please, don't nitpick, I am aware of wet bulb thermometers)

Wet bulb temperature is combination of temperature and humidity.

The simple layman way to understand it is it says what minimum temperature an object can attain by evaporating water off it, in perfect conditions (forced airflow, full shade, no internal heating, etc.)

When air is dry, even if it is hot you can evaporate sweat and cool down -- the wet bulb temperature is low in dry air.

You can survive on Sahara because while the air can be very hot, it is also dry. You sweat and you cool down.

As the humidity rises, the wet bulb temperature approaches dry bulb temperature and at 100% humidity they are both the same.

When air is 100% humid you cannot cool down by sweating at all -- the sweat will not evaporate in 100% humidity regardless of temperature.

Meaning that an air with 35C and 100% humidity has 35C wet bulb temperature but so can hotter air that has less than 100% humidity. The hotter air the lower humidity is needed for the object to cool down to 35C.

Wet bulb of 35C is a limit of human endurance. Even if you lie down in shade and do nothing and are completely healthy, your body is barely able to remove enough heat to survive. Any higher temperature and you WILL eventually die.

People who need to work (like move around at all) or are sick or are small (kids) will die faster.

The only way to resolve this issue is to dry the air somehow.

Things that don't work:

-- going into shade. You are still going to die, just a little bit slower.

-- having a fan. It can't cool you down, because water will not evaporate to cool anything below wet bulb temperature. You are going to die.

-- going into cellar. The air will get cooler but the humidity will rise. You are going to die, unless you can cool the air DRY BULB temperature below 35C. At which point your cellar will have water condensing on its walls which means you can remove humidity from air. It will be shitty, wet, 100% humid, hot place, to sit half a day in with your family, kids and neighbors that don't have an expansive cellar like you, but at least you will survive. Yay...

The issue is in areas that tend to be very hot and susceptible to this phenomenon, people tend to not have means to dry the air. They either don't have money for equipment or they have open homes (who keeps their home shut in a climate like that) assuming they have home at all.

From economic point of view, the problem is that even under wet bulb temperature of 35C some people will already be dying and others will have to stop whatever they are doing, which is not good for your economy.

> please, don't nitpick, I am aware of wet bulb thermometers

I don’t want to nitpick. Everything you wrote is correct as far as I know. I only want to add to it.

I think understanding what a wet bulb thermometer is crucial to understand the term. And it is a very simple thing: you take a totally normal thermometer, you put it in the shade. So far everything is normal, this is how you measure air temperature since forever. You then put a little sock on the end of the thermometer and make it wet. Super simple. On a traditional mercury thermometer the end is a little glass sphere where the mercury is stored. This glass sphere is called the “bulb”. A wet bulb thermometer is just a thermometer where the bulb is wet. Super simple.

Why would you do this? Obviously this “wet bulb” thermometer will measure a lower temperature than the dry one. This is because evaporation of the water takes away energy from the thermometer. The faster the water can evaporate bigger the difference you will see between the dry and the wet thermometers. If the air is saturated with water vapor then the two measurements will be the same. If the air is dry you will have lots of evaporation and the wet bulb will be way colder than the dry one. So if all you have is two thermometers a sock and a bucket of water you can measure the relative humidity in this indirect way by comparing the two temperatures.

An other way to think about a wet bulb thermometer is that it is a very crude modell of a sweating human. You keep the sock wet and that simulates the thermometer sweating. The temperature the termometer reaches is the limit of temperature you can cool yourself down using evaporative cooling.

Yes, this is completely correct.

I would add the wet bulb thermometer needs large evaporation area (so the sock cannot be too wet and definitely you can't put it in the bucket) and/or some airflow around it. Otherwise it will show some temperature between actual dry bulb and wet bulb temperatures.

In practice, nobody seriously uses wet bulb thermometers outside of school experiments because they are such a PITA. It is easier to just measure dry bulb temperature and humidity separately and then look up wbt in a table.

In general measuring temperatures correctly is a tricky business, what with temperature gradients in the objects you try to measure and the thermometer itself. I just recently needed to explain to a bunch of people why there is no such thing as "temperature in the sun" and that you can pick any temperature between WBT and around 5800K and it is going to be a correct temperature "in the sun" depending on properties and shape of the object you are trying to measure..

>nobody seriously uses wet bulb thermometers outside of school experiments because they are such a PITA. It is easier to just measure dry bulb temperature and humidity

How is humidity typically measured? I was under the assumption a hygrometer uses both dry and wet bulb measurements.

The traditional 5 dollar analog hygrometer uses a paper/metallic strip coil:

https://www.youtube.com/watch?v=jCUHDFYdG44

Wet bulb requires it to be... you know... wet.

Not very practical to include in your electronics.

I don't know exact method used but I can assure you, there is no water reservoir in any of my gadgets:)

> going into cellar. The air will get cooler but the humidity will rise. You are going to die, unless you can cool the air DRY BULB temperature below 35C.

Don't you mean wet bulb temperature? Why would you need a dry bulb temperature below 35C?

> It will be shitty, wet, 100% humid, hot place, to sit half a day in with your family, kids and neighbors that don't have an expansive cellar like you, but at least you will survive

If we do start seeing this kind of temperature around the world, I expect people will start building underground refugees or repurposing existing structures.

I mean DRY BULB temperature. Reducing dry bulb temperature == removing heat. Reducing wet bulb temperature == removing humidity.

But it doesn't matter a lot, because at 100% humidity (required to spontaneously dew humidity out of air) dry bulb temperature equals wet bulb temperature.

Dry bulb changes indpendently of wet bulb temperature but cannot be lower than wet bulb temperature.

Because when air temperature (dry bulb) reaches wet bulb temperature you are at dew point and when you cool down further all that moisture is going to either cause mist or dew or snow or rime.

In fact, lowering DRY BULB temperature under dew point (WET BULB temperature) is the leading way to remove humidity in nature -- the water precipitates in the form of mist high up in the atmosphere, the mist coalesces into droplets and falls down on air as rain. Alternatively, if the temperature is below zero, it causes snow by sublimation (both wet and dry bulb temperatures are equal.

>Reducing dry bulb temperature == removing heat. Reducing wet bulb temperature == removing humidity.

This isn't the best interpretation. Both reducing humidity and reducing dry-bulb temperature can reduce the amount of energy in the air.

Take a look at a psychrometric chart [1]. If you hold the humidity constant and reduce dry bulb temperature, you indeed reduce the enthalpy (what I interpret you mean by 'heat'). Likewise, if you keep the dry-bulb temperature constant and reduce the humidity you also reduce the enthalpy

To your point, this is why fixed dry-bulb economizers aren't recommended in humid climates as a means of conserving air-conditioning energy by bringing in outside air but enthalpy controllers are allowed across all zones.

[1] https://www.engineeringtoolbox.com/docs/documents/816/psychr...

> going into cellar. The air will get cooler but the humidity will rise.

If we are already counting on a wet bulb temperature of 35C, the humidity is likely already very close to 100%.

Reducing the temperature is likely to be a net good.

That's false.

TLDR: The air gets cooler but still can't cool you. Your body produces heat that has nowhere to go and you still die. Then the walls of the cellar heat up immediately, because cooling 100% humid air requires sinking a lot of energy.

If you found yourself in conditions of an actual heat wave as described, you would despair at the fact the air can get cooler in your cellar but it doesn't cool you at all.

Which is counterintuitive but unfortunately that's how physics works.

First, humidity does not have to be very close to 100%.

In fact, in most cases it isn't and the reported waves of 35C WBT are almost all between 42 and 44C in absolute temperature. This means the air has to cool down 7-9 degrees before it even reaches dew point.

7-9 degrees is a huge temperature difference when temperature is over 40C.

Unfortunately the problem isn't the air temperature. The problem is your body's ability to remove heat. And if you take air and cool it down the temperature will drop but humidity will rise. The wet bulb temperature is preserved unless you can somehow remove water from air. And with wet bulb temperature being same 35C your body still doesn't have any way to remove heat and you are still going to die.

Only after the air cools down by 7-9 degrees celsius you can start seeing any effects, but don't be too happy.

Because physics has a nasty trick to play on you.

The effects of water condensing on walls of your cellar is going to be your cellar walls heating up immediately.

Yes, water cools stuff efficiently when it evaporates but just as efficiently it heats it up when it condenses.

Conservation of energy is a bitch. Please, learn some physics, it is really fun. And sometimes terrifying.

So your cellar is very likely to have very limited ability to cool down very hot humid air and condense water out of it.

This is all fascinating stuff to me, I'd never really heard of wet bulb before. Quick question though: how does the pressure difference play into this in a basement? As far as I'm aware below ground pressure and voids under basements tend to cause pressure differentials in even non-AC basements (causing radon issues where I'm from)? I assume this would help a cellar situation in the event of power outage as air even slightly below ground tends to be much cooler than above ground air?

The pressure difference between your backyard and your basement is for all practical purposes null. It is also orders of magnitude smaller than those caused by gusts of wind and changing weather.

>The effects of water condensing on walls of your cellar is going to be your cellar walls heating up immediately.

While true about the conservation of energy, the drastic differences in both mass and heat capacity of air/earth mean the cellar walls will probably have no perceptible change in temperature.

> TLDR: The air gets cooler but still can't cool you.

Evaporative cooling is not the only kind of cooling that exists.

If this were the case you’d die of heat death standing in the middle of 100% humidity antarctica.

If your cellar is cold enough you’ll be in a much better situation than before. You seem to assume that the moment you open your cellar door, all humidity and temperature will immediately equalize with the outside.

Again, completely wrong. 100% humid 0C air is still 0C wet bulb temperature -- perfectly good for cooling you down.

Here's a discussion of heat index and wet-bulb temps, with records from around the world.

https://www.wunderground.com/blog/weatherhistorian/record-de...

The most dangerous / frequent occurrences seem to be measured in the middle east near shallow gulf coasts. Appleton Wisconsin holds the continental US record, apparently?

This is from 2011.

Here: https://www.weather.gov/jetstream/hi

says:

> The highest dew points, and therefore the highest heat indices are usually found near warm bodies of water.

> In the world, the warmest water is found in the Persian Gulf where the water temperature typically reaches up to 90°F (32°C) in summer. Therefore dew points will be that high as well.

> The highest dew point ever recorded, 95°F (35°C), was recorded at Dhahran, Saudi Arabia, on July 8, 2003. With an air temperature of 108°F (42°C) the heat index was 178°F (81°C).

> Appleton, Wisconsin also had a 90°F (32°C) dew point on July 13, 1995 with a heat index of 149°F (65°C)."

So, it happened once.

At the start of the article: "Results suggest that, under the business-as-usual RCP8.5 emissions scenario..."

Roger Pielke is good about this. He points out that the "business-as-usual" scenario is extremely unlikely:

https://rogerpielkejr.substack.com/p/the-unstoppable-momentu...

I'm not arguing that the original article is uninformative or unimportant.

The RCP8.5 scenario would require that humanity burned almost every last drop of oil and did nothing to mitigate carbon. That's not likely because the remaining fossil fuel deposits are significantly more costly and energy-intensive to extract. Eventually the energy return on energy invested will drop to economically nonviable levels. It's debatable whether the carbon emitted in 8.5 is even physically possible.

My guess is humans collaborating on a green future will mitigate emissions ever so slightly. But it will be energy/financial crises that force us to.

So can we look forward to fewer impacts under a more moderate pathway (say 4.5 w/m^2)? Probably not. The IPCC has consistently under-estimated the impacts and ignored feedback loops. Even the latest AR6 report says "Additional ecosystem responses to warming not yet fully included in climate models, such as CO2 and CH4 fluxes from wetlands, permafrost thaw and wildfires, would further increase concentrations of these gases in the atmosphere." We're locked into runaway climate impacts for centuries either way, not much of a consolation prize.

Obviously no one wants this to happen, but I wonder about any possible mitigation strategies. Like creating homes and infrastructure under the ground, or at least covered by lots of insulation, like a Moon base covered with lots of dirt.

Of course, that would completely suck for the people who have to live there, and we should do our best to prevent it, but some people probably aren't going to have a choice but to try and handle it in whatever way they can.

https://www.insider.com/coober-pedy-australia-underground-mi...

Coober Pedy everywhere I guess.

One kind of building that I came across is called an "Earthship", which relies on "thermal mass construction and natural cross-ventilation to regulate indoor temperature".[1]

It will be somewhat difficult to retrofit buildings to take advantage of e.g. thermal mass inertia, but I'm hopeful that new construction will increasingly favor passive/low-energy cooling methods.

[1] https://en.wikipedia.org/wiki/Earthship

I’ve been saying for years now that we’ll most probably see a time in our lifetime where you need to wear a (light) space-suit style thing to go outside in some seasons. Insulated and actively heated/cooled, possible with air filtration for pollution/smoke/etc. There’s already been some companies playing with the idea as a prototype/art/statement level but I truly think it’s inevitable that it becomes more common.

The spice must flow...

They make refrigeration systems for people who work outside. It’s a giant compressor that cools a liquid and moves that liquid through a tube and across a persons body via a vest. I remember one guy who owns a roofing business was saying that it’s totally worth the money to cool your crew down because your guys actually work faster and also you won’t have any heat injuries.

There are 4 broad scenarios according to which (or a combination thereof) the climate emergency will develop:

1) In a giant case of prisoners' dilemma, the humanity will coordinate worldwide and rise to the occasion, massively cut emissions, tax carbon, build out renewables, etc.

2) There will be massive technological breakthru-s in carbon capture and/or energy production and/or geo-engineering (and I am not talking about things like nuclear, where the tech is mostly there but the rising-to-the-occasion bit is missing).

3) Somehow, the models and projections would turn out to be overblown, or the more mellow of the serious models that project we lose N% GDP or whatever would turn out to be correct.

4) We're doomed, doomed!

Given the humanity's realistic record with (1) and (3)... either fusion works, or [0]

[0] https://www.youtube.com/watch?v=cRHOcWj--cs

I think the most likely scenario is 5) The climate changes, and humanity adapts to live in the new climate.

Humanity adapts and carries on. People are fucked.

That is somewhere between 3 and 4.

Whether it's 2050, 2060, or 2070 for going carbon neutral does not actually matter that much. It's one of the main points people are haggling about right now (e.g. in Glasgow at the climate change conference in a few months). Which will feature a lot of #1 enabled by #2. How good or bad our models are right now is going to be of interest to historians only (i.e. #3). We'll dodge extinction but will likely deal with the aftermath of our past actions for centuries regardless. But getting to carbon neutral seems to get us to a stage where we might manage.

The point is that we can call a date for this at all at this point because things are happening that are going to make that a reality. That's because of technical breakthroughs (i.e. scenario #2) that mostly already happened. And more is on the way. So any conservative date policicans call, might end up moving to an earlier date when that happens.

Whether you consider nuclear/fusion part of this progress is a bit of a political topic. My point is that we'll be fine with or without that happening. The "we're doomed unless we bet everything on technology X" scenario is basically just a variant of #4.

Actually, we're just dealing with the logistical aftermath of the results of these technical breakthroughs not being ubiquitous yet. But technically there's no other reason to keep burning stuff (coal, wood, gas, peat, etc.) other than that we are dependent on burning lots of it with our existing and increasingly more expensive to operate infrastructure. It's cheaper to not do that already but it just takes time to get ourselves there. 30-40 years sounds about right for getting that done.

Fixing our infrastructure is much less dependent on new technical breakthroughs (e.g. fusion or nuclear) than it is on simply doing more of the (already profitable) things that are being done anyway. Whether it is building gigafactories for batteries, building off shore wind farms, or deploying solar; it all seems to have decent ROI and popular with investors. Unlocking more capital for this is actually becoming easy and uncontroversial. If you separate the moralism and rhetoric from the economics, even the most conservative climate change deniers would not mind some cheap solar on their roof, lower electricity bills, or a ridiculous electrical ford truck with low cost and operational expenses. Paying less for more is a great way to drive progress and incentivize the masses. That's not to say that further breakthroughs aren't needed. They are, and they will happen as well. And IMHO speed up the agenda here.

My money is on space sunshades.

While it would cost tens of trillions to make a sunshade by launching from Earth, making sunshades and launching them from the moon should be viable thanks to the lack of atmosphere and low gravity. Assuming that a few million tons of mass is enough to set up a space sunshade manufacturing station (and railgun launch rails) it should only cost a few trillion dollars, cheaper than reducing CO2 emissions.

Stratospheric aerosol injection is cheaper and we've got plenty of data for that, as it mimics how volcanic eruptions cool the earth.

Aerosols are far harder to control and to predict harmful secondary/tertiary effects than simply reducing amount of sunlight in a particular area.

Has anyone considered altering wave patterns to increase ocean surface reflectance? Like a Fresnel lens magnification in reverse.

Thanks for distilling the situation so well. I’ve been stuck obsessing over the doomsday scenario. It’s easy to forget there’s other possible futures that might lessen my anxiety and push me to make certain helpful personal and career choices.

Its funny how many people inflate their importance and think their occupation makes the world go round. In reality it takes a lot of people to keep everything in working order. Specially low wage labor is of disproportional importance. Work done by people who are often (or by definition) financially fragile. A good number of these (and slightly above) involve manual work in already harsh (if not hot) environment. When things get unbearable these people will look at their cards, fold and run away leaving hard to predict holes in the economy.

Many more humans die of cold exposure than heat exposure each year. Less extreme cold + more extreme heat would possibly, if not likely, lead to many fewer human deaths. https://www.thelancet.com/journals/lanplh/article/PIIS2542-5...

Can we start considering high tech solutions to actively cool the planet? We're going to slowly work on carbon, but it won't be fast enough. In the meantime, We need to prevent heat getting to Earth, either via more cloud cover or space mirrors in the LaGrange point.

I'm not a fan of either, but what's the alternative? Bake to death while the powerful decision makers delay changing anything?

We can’t. Let’s say that you find a magic box that can offset 20% of the carbon emissions globally. Yay you just reduced carbon emissions. But there is no budget for carbon emissions. So those who produce it (agriculture, heavy industry) can now feel free to just produce more CO2 and toss it into the air. Besides, not every place is as industrialized as the US or China but they want to be. So the emissions will soon catch up to the old levels while your machine is cranking at full speed.

It’s the equivalent of getting a second job because you can’t stop spending money: it’ll offset when you go broke but won’t prevent it. The only way to fix this is to tax the shit out of anything that pollutes with CO2 or other greenhouse gasses (which will naturally be passed on as a cost to consumers). There is jo other way out.

If (some) people already emit however much CO2 they want, why would offsetting emissions cause them to emit even more?

People emit little CO2 by themselves. Your choice of a Prius vs a Camry isn’t by and large as important as the food you eat. Just by being alive you are consuming about 10kW if you live in the US, the majority of which is the fact that the food you eat is grown on mega farms. Between agricultural machinery, fertilizer, and transportation of that food from the farms to your grocery store, that’s the major part of your energy consumption. Per capita energy consumption is a surprisingly strong indicator of quality of life. Third world countries often top out at less than 1kW for example.

So in a world where everyone is trying to get to a high quality of life and only about 1B out of 8B have it, and in a world where for 7B to get to that quality of life we need to increase their energy consumption by a factor of 5-10, we are in a constant increase of total human energy consumption. Combined with population growth, we are nowhere near peak human CO2 output. In other words if you can make a device that can remove 20x of the CO2 we are currently putting out, then yes we could use that tech, assuming we don’t come up with some more quality of life ideas that push the energy budget further up the scale of course. But anything less than that won’t be enough as there is an accelerating growth in CO2 emissions with more or less no end in sight.

Unfortunately most solutions are in the realm of science fiction, solar shades and the like.

Here again, one of those cases where as a non-native English speaker, despite 12+ years living in English-speaking countries and working for English-speaking companies, I encounter a term for the first time in my 44-years old life: "wet-bulb".

The wet-bulb temperature is defined as the temperature of a parcel of air cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat supplied by the parcel.

[0]: https://en.wikipedia.org/wiki/Wet-bulb_temperature

Not exactly new news:

https://www.sciencealert.com/middle-east-may-be-uninhabitabl...

Fun fact:

With rising sea levels a lot of people there will be a lot nearer to a big enough body of water to cool their heat.

Or not, since the humidity at coastal areas is higher:

https://meteologix.com/ae/observations/wet-bulb-temperature....

But don't worry, ironically the people who so generously provided the raw materials needed to raise global temperatures and sea levels are equally working on solutions to keep their asses out of the heat and their feet from getting wet.

https://www.thenationalnews.com/uae/environment/climate-chan...

https://www.tandfonline.com/doi/abs/10.1080/02697459.2020.18...

From the abstract of the last paper, which isn't fully available online, sadly: "...this paper ventures regional planning responses to adapt to these threats through decentralising populations to inland areas."

Dispersion to the inland areas?

Sure, but the inland areas of which countries?

...

But if they are lucky, they will maybe provide the material for cool and vast underground arcologies that could even reduce carbon dioxide emission from the building industry:

https://www.bft-international.com/en/artikel/bft_Environment...

More than half these comments are meaningless because they misunderstand what Wet Bulb temperature is.

I too didn’t understand what Wet Bulb temperatures meant until I used this calculator: https://www.omnicalculator.com/physics/wet-bulb

95F TB (Temperature Wet Bulb) is when the humidity is 100% and it is 95F out. The lower the humidity, the lower the TB value. At 40% humidity and 120F temperature, you get 96F TB. Imagine 120F at 40% humidity. Insane, right?

That’s what kind of temperatures this paper is talking about: dangerously hot and humid.

The gloom and doom posts on HN seem to be increasing lately. I can go to CNN if I want this kind of content.

That being said I would be ok with posts talking about fixing climate change especially if it preserves human rights and dignity.

Of all the gibberish conspiracy theories about the downfall of society, this is the one thing that's definitely happening and needs to be addressed urgently.

Don't worry about it. All this "doom and gloom" stuff will only affect the poor in far away countries. It'll be decades before it seriously impacts your way of life.

I hope it does impact rich countries soon though. That's the only way they'll take the problem seriously without pushing vague ideals like "human rights and dignity"

Strangely enough, there seems to be a correlation between governments and people ignoring the effects of their actions on the climate, and the doom and gloom posts.

I wonder why.

How is that "gloom and doom"?

He doesn't want to sacrifice anything or changes that will affect him personally.

In your book, what counts as fixing climate while preserving human rights and dignity?

Good question. I could do some examples.

Good: carbon tax or cap and trade (ideally revenue neutral). Electric car subsidies.

Bad: climate lockdowns. Restricting travel. Travel credits. Social credit score tied to climate behavior. (This stuff keeps me up at night)

So bottom line:

Following this https://www.un.org/en/about-us/universal-declaration-of-huma... and this https://en.m.wikipedia.org/wiki/United_States_Bill_of_Rights and you’re fine in my book.

But that’s not an assumption I make these days.

What about just nationalizing the entire energy industry and everything related, instead of trying to work within the parameters of a free market for something with so many externalities?

Call me Mr Glass Half Full, but since cold kills 20x more people than heat shouldn't we look forward to a future where many more people survive temperature extremes?

https://www.sciencedaily.com/releases/2015/05/150520193831.h...

No! Not even a little bit. Do you realize the rapidity of these changes puts our entire species at risk?

> The air humidity indoors will be to high to survive!, people will die!

Seems an easily solvable problem

https://en.wikipedia.org/wiki/Silica_gel

You are welcome. Sleep well tonight

Another problem is that in wet conditions the virus aerosols spread much more rapidly. If people crowd into cooling shelters they’ll all get covid, masks or no masks.

Where can you find historical wet bulb temperatures for a specific locality?

Will any non-human mammals survive in these places? This sucks.

35C = 95F for those of us who are in the USA.

Wet bulb 35°C, which feels like 160°F dry bulb for those of us who are in the USA with varying amounts of water in the air.

> The wet-bulb temperature is defined as the temperature of a parcel of air cooled to saturation (100% relative humidity) by the evaporation of water into it ... The theoretical limit to human survival for more than a few hours in the shade, even with unlimited water, is 35 °C (95 °F) – theoretically equivalent to a heat index of 70 °C (160 °F)

https://en.wikipedia.org/wiki/Wet-bulb_temperature

A wet-bulb temperature of 35C is equivalent to a heat index of 70C (160F).

Tell that to the conservatives/climate change deniers. They are already in favour of "moving inland" to combat rising sea levels due to climate change. I'm sure they are also in favour of evolving mankind to be able to survive harsh climate.

[deleted]

The limit is 35°C wet bulb temperature. The temperature you're accustomed to reading is dry bulb. You can't compare wet and dry bulb readings; they're completely different measures.

The annual maximum wet bulb temperature in Arizona the last few years has been about 24°C. You were nowhere near the limit.

Using some random internet web-based calculator, apparently 50° C (122° F) at 34% humidity is just under 35° C (95° F) wet bulb temperature.

The calculator wouldn't go above 50° C, so I don't know what the temperature would be at 0% humidity.

The key here is humidity. With low humidity it's possible to lose heat through perspiration. With high humidity it's not.

Yes, you're right, I've updated my post to remove that bit.

It gets to 115+F where I live, sometimes for a few days. If you go outside bald in full sun without a hat, within seconds it feels as though your brain is cooking in your skull. It's liveable for a short stretch, but seriously discourages you from going outside. Parts of the garden crisp up and die in a day.

This post appears to be fully within the Hacker News "approach to comments" and "site guidelines".

The atmospheric temperature discussed as dangerous has been common in many parts of the earth for many years and is not nearly new. The real threat discussed is from heavy consideration of

"business-as-usual RCP8.5 emissions scenario"

and that is based on climate models evaluating the future, 2050+, effects of human sources of CO2 on temperature and climate.

We have a long history of such models. Apparently they are usually based on the fact that CO2 is a greenhouse gas.

The main question about CO2 is how much warming will be caused by a given quantity of CO2 from human activities.

Yes, CO2 is a greenhouse gas, but maybe surprisingly so far from either observations or models, we have no credible evidence that human sources of CO2 have caused, are causing, or will cause significant warming.

Okay, let's look at the observational data:

There was a movie, An Inconvenient Truth. With data from Antarctic ice cores, the movie showed, for the atmosphere, a graph of temperature and CO2 concentrations going back about 800,000 years.

As I watched the movie, it appeared that the claim was that the graph showed temperature and CO2 concentrations going up and down together. Then the movie concluded that the higher concentrations of CO2 caused the higher temperatures. Then there was a claim that currently more CO2 from human activities would rapidly cause significantly higher temperatures.

But, we could look at that graph more closely, and doing that we will see three situations:

(1) When temperature started to increase, CO2 (concentration, here and below) was low, not high. So, something caused the warming, but it was not high CO2.

(2) About 800 years later, CO2 had increased. Presumably the cause was more biological activity from the higher temperatures.

(3) Some thousands of years later, while CO2 was high, the temperatures fell again. There was a cause, but it was not low CO2. Indeed, the high CO2 did not keep temperatures from falling.

Net, from that 800,000 years of data, there is no evidence that high CO2 caused high temperatures. It would be more accurate (though of course still wrong) to say that the data supported that CO2 caused LOWER temperatures.

For some more recent data, there was some significant warming during the time of the Roman Empire and during the Medieval Warm Period, and there is no evidence that the cause was high CO2. There was some significant cooling during the Little Ice Age from roughly 1300 to 1900, but there is no evidence that the cause was low CO2. There was some cooling from 1940 to 1970 and concerns in the media about another ice age, and those years were when there was more CO2 from human activity from WWII and the post-war economic boom. So, in those years, with more CO2, we got some cooling instead of warming.

Again it would be more accurate (though of course still wrong) to say that the data supported that CO2 caused COOLING.

For some details, can start with "Global Cooling" at

https://en.wikipedia.org/wiki/Global_cooling#1974_Time_magaz...

which discusses the two famous magazine stories, the 1974 Time story and the 1975 Newsweek story, worrying about "global cooling" and asking if we were entering a new ice age. For more on these magazine stories, at

https://longreads.com/2017/04/13/in-1975-newsweek-predicted-...

can see the April 28, 1975, Newsweek article “The Cooling World”.

So, net, there is no data on temperature and CO2 from the past that says that CO2 will cause warming.

Yes, CO2 is a greenhouse gas. This means that it absorbs some light in the infrared but not the visible. In the case of CO2, it absorbs light out in the infrared in three narrow bands. The absorption spectrum is given at

https://webbook.nist.gov/cgi/cbook.cgi?Spec=C124389&Index=0&...

Part of the mechanism is Planck black body radiation.

We have had some warming since the Little Ice Age. It may be that we are still pulling out of the Little Ice Age, e.g., it can take a long time for the oceans to warm up. But even with this warming, it's cooler than in the Medieval Warm period and the Roman times when the polar bears didn't go extinct, the ice in Greenland and the Antarctic didn't melt, the oceans didn't rise and flood the coasts, and apparently humans didn't suffer. Apparently the main effects were greater agricultural productivity, e.g., in England, grapes were grown for wine.

Could the warming since the Little Ice Age be due to CO2? No: The warming is at the surface, and CO2 absorbs high in the troposphere with definition at Google:

<blockquote>the lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7–6.2 miles (6–10 km), which is the lower boundary of the stratosphere. </blockquote>

which, from MIT climate scientist Richard Lindzen, Alfred P Sloan Professor of Atmospheric Sciences, Emeritus, at Massachusetts Institute of Technology, has gotten cooler, not warmer.

Several attempts were made to model the atmosphere and calculate and predict the effects of human sources of CO2 on temperature. Nearly all the efforts predicted temperature increases that were rapid and significant.

It has now been some years since the times of the predictions, and the predictions and reality are compared in the graph at

http://www.energyadvocate.com/gc1.jpg

Summary: Nearly all the predictions were way too high.

Science: So, so far climate modeling has no predictive value and, thus, is not good science.

Result: The predictions have no meaningful credibility.

Current Summary: There is no credible evidence from either the 800,000 years of the earth or the climate models that human sources of CO2 have had, are having, or will have significant effects on temperature or climate.

As a result of this lack of evidence, there is no scientific reason to attempt to lower human sources of CO2.

If you posted this in the 90s, it still would be a terrible, uneducated post.

Read this, all of it, then come back here and make your argument again: https://www.ipcc.ch/assessment-report/ar6/

Resolving at least what is in my post is much easier than working through the IPCC's reports:

It's simple, really simple, just as in my post:

Observational data: The main observational data used to argue the dangerous effects of CO2 is just the 800,000 years of ice core data. But just looking at that data, as I explained in fine detail, that data does not support the claimed effects of CO2.

Models. Again as I explained carefully, so far the climate models have been proven wrong by reality and, in particular, have no predictive value and, thus, are not good science.

Net, there is nothing credible in data or models that says human sources of CO2 will cause significant warming.

In particular, the IPCC has no data or models that do better.

If you want to make an argument for being alarmed, I can do better than the IPCC: We don't really know what CO2 will do. In particular we have no data or models that are credible and say that we are safe.

I have shown, in just one simple post, that the alarmists don't have credible evidence. But I have not shown that we are safe.

Now the next real question is, what to do when we don't have any credible evidence that we are safe or not.

https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6...

"It is unequivocal that human influence has warmed the global climate system since pre-industrial times."

"The likely range of human-induced warming in global-mean surface air temperature (GSAT) in 2010–2019 relative to 1850–1900 is 0.8°C–1.3°C, encompassing the observed warming of 0.9°C–1.2°C, while the change attributable to natural forcings is only −0.1°C–0.1°C."

This is as far as I go to help educate you, as I remain unconvinced any efforts to do more would be helpful.

It’s wild to me that even the Biden administration appears so cavalier on climate. $1.2T on infrastructure and a follow up $3.5T budget bill and in both the environmental provisions are lame. Still no carbon pricing or anything that might make Exxon execs too uncomfortable (yes, I know Exxon supports carbon pricing in public because they don’t think anyone will actually do it).

It's not as much what he would do as what he could do. Not everything is going to fly through the house and senate with ease.

I imagine it would be a lot easier if it weren’t bundled with trillions of dollars for other programs. It kind of feels like climate should be the number one priority and while Republicans are close to worthless it feels like Democratic politicians aren’t much more interested in offending their corporate masters. But in general I agree, it’s hard to get these things passed when so many congresspeople are in the pockets of moneyed interests.

Blame Congress for the poor investments in America's future. Biden's direct influence is limited to the executive branch.

Traditionally presidents set the agenda and work to get support, but you’re right that it’s a team sport and Biden needs congressional support. It’s disappointing that there isn’t enough support even among Democrats (Biden is trying to push through a $3.5T budget plan without any Republican support so clearly he thinks he can get things done on just a Democratic basis, but apparently he doesn’t think major climate initiatives will be popular with the Democratic crowd?).

While it's great and all for america to invest in the environment at the end of the day america is still only a small part of the world. The issues of climate are global in nature and unlikely to be solved in my lifetime.

The US needs to be leading on this issue. They're the largest economy and have benefited the most out of everyone (on a per-capita basis) from the carbon pollution that they're causing, leaving the poorer and hotter countries in the global south to bear the brunt of the downside a century later.

Agreed. It’s going to be pretty lame when Biden tries to convince the world to do better on climate at the upcoming summit when Biden can’t get significant policy implemented at home. Anyway, every country needs to do its part and ours, like many others, is failing.

There being an energy imbalance in the world comes from somewhere. It could not have come, at least not so fast, without an imbalance in the human psyche for the last couple of hundred years.

How much is enough, when is enough enough, what is my purpose for existing, how can I be of service while not being taken advantaged of, and without unreasonable demands?

There is a need for reckoning, though it needs to start from within.

This crisis may be of a more spiritual nature than is evident on the surface.

It's hilarious to me that people somehow think hot is MUCH more dangerous than cold. If you do any homework you will see which end results in more deaths.

We can distribute blankets and warm clothes to practically anywhere at scale. You can't scale air conditioners the same.

Your "homework" doesn't matter if super heat waves are a new phenomenon since data was collected.

You can't even glean anything useful from total deaths of heat vs cold. You'd need an equal number of people in equally hostile hot/cold environments of the same size. And even then there's still so many other variables can contribute to a result.

If you clicked on the link you are commenting about, you would have learn that we are talking about 35°C wet bulb. Which will kill you, whatever your age, your health, or what you try to do to overcome it. Basically, without air conditioning, so without energy, you are dead.

Cold, instead, will not kill you if you are able to cover yourself with a sufficient coat and/or you are able to start some fire.

Most places in the world, even in rich countries, neither have air conditioning nor sufficient energy power plants to cool everyone.

People who own a car in Yakutsk must leave it running all winter, or the oil will freeze & cause engine damage. A toolbox is always present in the car, since being stranded on the road, without cell phone signal, will lead to death within a couple of hours. Having a part of your ears exposed for 15 minutes will lead to frostbite. Cold is no joke...

Well, one can warm up by eatnig lots of food, wearing other critters' skins, and burning stuff; all of which are stone-age (or earlier) technologies. Cooling down requires air conditioning (modern tech) or access to natural cold water (privilege)

Or digging a hole or holes, and running air and or water through them, like has been done for thousands of years in very hot places.

Huh. https://www.weather.gov/hazstat/

That's of course cherry picked. But I think the sucky part is increasing the variance of the temperature distribution. So the hot is hotter and the cold is colder, and both ends really suck.

According to this Lancet study, about 5M die from cold globally, annually, while about 500K die from heat:

https://www.thelancet.com/journals/lanplh/article/PIIS2542-5...

I found the article through this link: https://news.emory.edu/stories/2021/07/climate_change_heat_r...

Interestingly, the emory link did not quote how many deaths were due to cold vs heat, but it did say that cold related deaths were going down and heat related deaths were going up.

By cherry picking just the part of the article that support a global warming narrative, but leaving out that cold is still, by far, the main danger, emory is seriously misrepresenting the science, imo.

Btw, the Guardian coverage for the same article is only slightly better:

https://www.theguardian.com/world/2021/jul/08/extreme-temper...

While it does mention that cold kills more, it does not mention that the ratio is 10:1 in the study.

And yet, a lot more populated areas on the globe are susceptible to heat waves than to cold waves.

Not true. In fact, Africa is the place with the highest cold-related excess mortality. This [1] Lancet study estimates that almost 1.2M people die in Africa yearly due to cold, while only 25000 die from heat.

All-in-all 10 times more people die from cold every year (according to the study) than from heat.

[1] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5...

What numbers are you looking at where cold kills more people than heat?

"The study found that extreme heat and cold killed 5.08 million people on an average every year from 2000-2019. Of this, 4.6 million deaths on an average occurred annually due to extreme cold while 0.48 million deaths occurred due to extreme heat"

https://www.downtoearth.org.in/news/climate-change/extreme-t...

It's sadly probably more a societal wide mental illness. Big corps like the environmental movements can use the internet for wide spread control and have destroyed peoples minds.

You could argue the idea hot is bad meets expectations for hackers, computers should be kept air-conditioned. Although this is not quite true, I think uniformity is what matters (same as humans, sudden drops in cold like walking outside is what can kill)

And what runs better, a warm car or a cold car.

The number don't lie, but number don't matter. Telling people they will die in more and more crazy ways gets more control.

There's a far larger area of the world which is too cold & dry for human tolerance, yet people survive & thrive there. Probably the same for places which are hot & humid.

There are some interesting documentaries on Yakutsk, the "coldest city in the world".

I think it's good to note that Yakutia is burning at a rapid rate.

https://www.theguardian.com/world/2021/jul/20/everything-is-...

Very few people live in the cold and dry areas, though. If you compare the population densities of places like Siberia or Canada north of the Arctic circle, I think you will struggle to find a single city.

Norway and Russia have a handful of towns near the cost north of the Arctic Circle, but that is largely due to the Gulf Stream keeping the temperatures more livable. Inland, temperatures are not very compatible with human life.

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