[careinke]

Interesting conversation. I'm not doubting the whole WBT thing, but if true, that would mean you could not sit in a hot tub warmer than 35C for six hours without dying. I find that hard to believe.

I can tell you, if you get out of a swimming pool in Riyadh when it is 40+ C, you will freeze your a$$ off (of course the humidity is < 10 percent). It's a weird feeling.

[Ibon]

I have some cloud forest real estate at 2000m above sea level, water, forests, pastures, upper 50's in the morning, rarely reaches 80 at mid day. Cool climate. I am noticing low land bird species wandering up here more and more every year.... soon it might be dispossessed humans escaping the Wetbulb T Death.

Maybe one day we will run a refugee camp?

[vox_mundi]

Interesting conversation. I'm not doubting the whole WBT thing, but if true, that would mean you could not sit in a hot tub warmer than 35C for six hours without dying. I find that hard to believe.

I can tell you, if you get out of a swimming pool in Riyadh when it is 40+ C, you will freeze your a$$ off (of course the humidity is < 10 percent). It's a weird feeling.

The Dangers of Taking a Dip in the Hot Tub

... The annual number of emergency room visits has been steadily rising. In 2007, 6,646 people went to emergency rooms after a hot tub injury, compared with 2,549 in 1990.

About half the injuries were caused by slipping or falling, but heat overexposure was the problem in 10 percent of the accidents, and near-drowning in about 2.5 percent. “You should only use the hot tub for 10 to 15 minutes, and the temperature should be no higher than 104 degrees,” Dr. McKenzie said.

Hot Tubs and Heat Stroke

...“The body perspires in order to prevent increases in body temperature. At the same time blood flows through vessels near the surface of the skin, giving the flushed appearance of an overheated person. The cooling comes from the evaporation of the perspiration from the skin. If the perspiration cannot evaporate or is wiped off, the feedback loop is broken and the cooling does not occur. If a subject in a hot tub overheats, the same blood flow pattern and perspiration occur, but now heat flows into the body from the hot water in the tub. The feedback has become positive instead of negative, and heat stroke and possibly death occurs.”

... about 8000 people suffered from heat stroke accidents in hot tubs over 18 years, or over one per day. ... an understanding of biological thermodynamics and feedback loops has more than merely academic value.

[dohboi]

Thanks for the great stats, vox. It looks like everyone else just has suppositions, ill-remembered anecdotes, and argument-from-incredulity on their side.

[SeaGypsy]

Aside from those with basic ignorance of the principle, what are you saying to the others? We are not ignorant of the principle, but mostly disputing how often or if WBT is occurring for how long & where, aside from the rate of increased occurrence.

Very few posters here have lived in the places where the most common dangerous WBT events occur. For those that have, to be dismissed by those who have not, based on an argument of data versus anecdote when in fact mass death events from WBT are yet to occur, well it's a bit rich. A couple of thousand deaths in a city of millions is hardly the beginning of die off.

I would have thought more of a risk is the much lower tolerance of most of our key food crops. In conditions where temperature is over about 24c at dawn, rising & not falling below this all day, most plants will not grow. I would think this is more likely to affect vast areas of global agriculture much sooner than prolonged WBT becoming common.

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[careinke]

Thanks for the info Vox.

I would guess there are not even more hot tub deaths, because most people use hot tubs during cooler weather. Breathing cold air would probably help cool the body some, allowing for longer soak times.

[vox_mundi]

... I would have thought more of a risk is the much lower tolerance of most of our key food crops. In conditions where temperature is over about 24c at dawn, rising & not falling below this all day, most plants will not grow. I would think this is more likely to affect vast areas of global agriculture much sooner than prolonged WBT becoming common.

You're absolutely correct. Agriculture collapse would be a leading indicator as AGW starts to bite.

Effects on birds and animals that can't sweat will also precede impacts on man. This would likely take out many keystones species and cripple the ecosystem.

Heatwaves to hit wildlife hard

According to Professor Andrew McKechnie, a physiological ecologist from the University of Pretoria, South Africa, when the air temperature reaches 48°C, a small, sparrow-sized bird can lose about five per cent of its body mass every hour. This rate of water loss is so high that birds rapidly become dehydrated, and can die in a matter of hours.

"We suspect body mass maybe a key issue here, with larger birds at comparatively greater risk of direct hyperthermia … and smaller birds conversely at greater risk of dehydration," McKechnie says.

Of course, birds are not the only species under stress during heat waves. Another animal highly susceptible to heat is the flying fox. Because these bats form colonies comprising thousands of individuals, it gives ecologists like Justin Welbergen, an evolutionary ecologist at James Cook University in Townsville, a unique opportunity to study something close to an entire population of a species.

As soon as air temperatures climb into the 30s, flying foxes experience heat stress. Above 42°C, the black flying fox (Pteropus alecto), found along the northern Australian coast, start dying; at around 44°C, so too does the grey-headed flying fox (Pteropus poliocephalus), found along the east coast.

These are the effects of just straight temperature with low humidity.

[kiwichick]

thanks for the excellent chart

reading off the numbers I am relieved to find I am still alive

not that's its hot here at the moment, the opposite in fact (snow still on the ground 9 days after it fell ) , but during our time in Australia the summer temperatures would often get to 40 C (105 F ) and sometimes 42 -44 (107 F - 110 F ? )

I think the all time record for our area ( inland NSW north of the Murray river ) was 47 C (116 F ? ) but the saving grace was that humidity levels were usually quite low ( sometimes less than 10 % ) , so that even on the hottest days we were only suffering severe stress.

and most of the time we could retreat to an air conditioned area

[SeaGypsy]

I spent a few summers in Alice Springs, where it is over 40 & not under 20 for several weeks. Humidity usually in the teens or twenties meant an evaporative a/c would bring the house down from outside shade temp 44 (sun 52) to 22-24 inside. Lucky there is plenty of groundwater, even if it is chalky.

From experience working outdoors peak summer as above is a lot easier to cope with, work early, 5 hour siesta, work late, than pre monsoon on the north coast. Once the rain starts some sanity is possible again, but the last dew weeks before are awful. It is easy to imagine tipping over into WBT late in the build up, early in the wet.

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[ennui2]

Thanks for the great stats, vox. It looks like everyone else just has suppositions, ill-remembered anecdotes, and argument-from-incredulity on their side.

No, the problem is you barreled in on this thread (including a sloppy typo (T) in the thread title) with this attitude like you had this epiphany about wet-bulb and suddenly you've got to run around screaming that we're all vulnerable to "cooking in our own skins" only to have us inject a little realism into the discussion, followed by you ridiculing us for it. Object to the word "hysterical" on sexist grounds all you want, but that's how you sounded. Use whatever term is most politically correct. If the shoe fits, wear it.

Yes, dohboi, it is an issue, but no, it is not as high on the list of pressing concerns as you're making it seem. Agricultural and water pressures will likely kill more people in the end than them "cooking in their skins" at the equator.

[dohboi]

what are you saying to the others? We are not ignorant of the principle, but mostly disputing how often or if WBT is occurring for how long & where, aside from the rate of increased occurrence.

Yes, that's the point. Right now 35+ wbt doesn't exist anywhere on earth in natural conditions for any length of time.

As GW proceeds, we will see more and more places approach, reach, and then exceed that mark for longer and longer periods of time.

Wherever that does happen for more than a few hours, everybody will die who cannot get into air conditioning or someplace otherwise cooled (like a cave or basement).

En, I've known about wbt for a good long time. It's you lot who seem to be new to the idea and incredulous about it.

The reactions to that raw fact from people here shows that even those who seem to accept all sorts of doom still have a hard time accepting that we will be making simply normal human existing on the planet impossible...we are in the process of creating a planet where in more and more places, starting with some of the most populated of them, you go outside of AC (or a basement or cave) and you die.

The whole point of the thread was that these conditions were not supposed to start to come about for many decades, at the earliest. But we are seeing places in South Asia approaching these conditions already now. And clearly just getting within a couple degrees of 35 wbt is very deadly to many people, even those long conditioned to living in high heat and humidity.

I may have had to get a bit rough, but that's what it takes, apparently, to slap some sense into some people who are persisting in denying reality.

(And, yes, of course, as more and more places approach and exceed 35 wbt, more and more of the earth will also become inhospitable also for the various plants and animals humans have come to depend on for their food. Maybe that will be what wipes up out first, or maybe some will figure out some work around for that; we are, after all, famously omnivorous. But there's no working around an atmosphere that has become lethal to human existence. And that's where we're heading, fast as we possibly can.)

("Yes, the world is careening uncontrollably into utter chaos and destruction, but we aught never to express any kind of emotion about it, dear me!" says en, clutching his pearls to his throat in consternation! )

[onlooker]

here is a good explanation of how heat waves can affect humans in particular heat with humidity.
http://www.ecoshock.info/

[ennui2]

It's you lot who seem to be new to the idea and incredulous about it.

Presumptuous of you to say that. I knew about wet bulb already.

The reactions to that raw fact from people here shows that even those who seem to accept all sorts of doom still have a hard time accepting

In other words, if we don't rate this doom the way you do, there's something "wrong" with us? What should we be doing in response? Pissing our pants? The future is bad enough already.

you go outside of AC (or a basement or cave) and you die.

You've painted this picture in your head that is decoupled from reality. It's a science-fiction dystopian picture. And you have now repeated this narrative of "you go outside and you die" again and again, as if billions of people are going to suddenly disappear off the face of the earth one day. It's NOT going to play out that way, dohboi. It's just not. The cases of heat waves causing mass deaths are rare and even when they become more common, they will still be rare events. Once temperatures become consistently that hot, people will move rather than walking outside and dropping dead.

I may have had to get a bit rough, but that's what it takes, apparently, to slap some sense into some people who are persisting in denying reality.

Look. I've been in Las Vegas before during the summer where you really can't survive for long outside without a water bottle or ducking back into a casino. I've been in Hot Springs California. I know what wilting heat feels like. We're not denying reality. Stop trying to be thought-police and impose your level of panic on the rest of us.

It really just sounds like you stumbled onto this news and are struggling to process it, hence your Charlton Heston act of running around screaming "Soylent Green, It's PEEEOPLE!!!!", but you're not the only one who knows about it and it isn't probably going to be the primary driver of die-off. Crop failures and water pressures will come first.

[dohboi]

" as if billions of people are going to suddenly disappear off the face of the earth one day"

Ummmm, that's your distopian fiction.

I never said any such thing.

Just stating the raw facts of what the consequences of having ambient conditions that are at or above 35 wbt mean.

Sorry that I can't control what your feverish mind constructs from those facts.

I'll keep in mind in the future that you might not be actually disagreeing with what I am actually saying, but with some fantastical picture your brain has magically constructed from what I've said, which fantasy then you, in further paroxysms of delusion, mis-attribute to moi. (I won't even touch the Charlton Heston thing, except to say, wow.)

[ennui2]

The point I (and others) have made to you, dohboi, is that those conditions happen very rarely on earth and will continue to be rare (albeit less rare) even with runaway global warming. Rare enough and gradual enough that people will move out of the wave of it. Of course, once we have climate refugees, that represents its own problems that are probably more severe than the threat of wet bulb death itself.

Yes, it's a concern, but when all is said and done, there aren't going to be that many people who step outside and cook in their own skin. So it's a theoretical concern that will never really manifest itself. Pointing to the heat stroke deaths in europe or in Pakistan/Afghanistan is purely anecdotal, and let's face it, they're a drop in the bucket compared to the total human population. More people die from auto accidents each year than heat stroke by several orders of magnitude.

[dohboi]

"those conditions happen very rarely on earth"

This is what I've been saying from the first.

"and will continue to be rare (albeit less rare) even with runaway global warming."

And you know that, how?? Did you read any of the linked research and articles. At some point, wbt's above 35 become widespread in most of the currently most populated areas on the earth.

"Rare enough and gradual enough that people will move out of the wave of it."

But that's not how this actually plays out. That's not how climate and weather work.

As I said above, conditions will be more and more likely to yield above 35 wbt conditions, but we just won't know exactly when or where or how soon a significant episode with those conditions will occur. In Pakistan, they just hit 33 wbt. That's just two degrees away from the total lethality of 35.

"Of course, once we have climate refugees"

Ummm, we already have lots of climate refugees.


"more severe than the threat of wet bulb death itself"

OK. "more sever than...death itself." Don't even know where to start with that one.

"there aren't going to be that many people who step outside and cook in their own skin."

??? That's exactly what has happened to thousands of people in south Asia during the recent heatwaves. Except they didn't exactly 'step outside,' mos of them had no airconditioned 'inside' to be in in the first place.

You do realize, don't you, that the US is about the most airconditioned place in the world, and most people, especially the poor, have little to no access to it, right?

The point about current heatwaves and the deaths from them is that they are tiny, miniature examples of what is going to happen in the future: There will be years of relatively little increase in heat and humidity levels, certainly in some locations, then suddenly conditions will change and lots and lots of people will die just from not being in AC (or in a cave).

I'll leave it there for now.

I don't know why you have such resistance to seeing the reality and gravity of this problem. I guess these things are indeed just too scary for some here to even contemplate.

Best to all in a rapidly heating and humidifying world.

[kiwichick]

@ doh

obviously correct if we assume that we can't , or don't , get onto a track taking us to rapid reductions in GHG's in the very near future

[dohboi]

+1

[Ibon]

I don't know why you have such resistance to seeing the reality and gravity of this problem. I guess these things are indeed just too scary for some here to even contemplate.

I think the main issue here is that we are still sitting smug in affluence. A whole string of environmental threats have been forecasted since 215 years (starting with Malthus) and here we are 7 billion plus and growing.

The trend is your friend comes to mind. That is a long trend line unbroken.

Expecting folks to question fundamental issues of human overshoot when the fundamental physical infrastructure continues to support a growing population is the very definition of futile.

Hence we must await the catalyst of consequences to break this long and resilient trend line.

It really is just that simple.

[onlooker]

Or to put it more bluntly, only when severe consequences affect the person in question will that person finally really awake!