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Houston is hot, but wet bulb temperatures > 35 C (95 F) -- different from standard air temperature -- are a different story. Afaik, for healthy humans, staying

Houston is hot, but wet bulb temperatures > 35 C (95 F) -- different from standard air temperature -- are a different story. Afaik, for healthy humans, staying outside > 35 C (not 36 C) for even long durations is physiologically impossible. Even healthy humans have trouble from 31 C (87.8 F). I don't have access to historic wet bulb data, but Houston appears to be in the mid-70s[1]. Places which have wet bulb temps > 35 C essentially shut down outside. You can use air conditioning indoors, but unless you have a Fremen-esque suit for outdoor workers, you can kiss outdoor activity goodbye in the daytime. In reality this mean the place essentially shuts down during the day. E.g. in Pakistan last year[2]. Being interested in history, I'm particularly mindful many historians speculate that climate change was responsible for ending the earliest known civilization in this area[3]. [1] http://cms.ashrae.biz/weatherdata/STATIONS/722430_p.pdf http://cms.ashrae.biz/weatherdata/STATIONS/722430_p.pdf [2] https://www.telegraph.co.uk/global-health/climate-and-people/hotter-human-body-can-handle-pakistan-city-broils-worlds-highest/ https://www.telegraph.co.uk/global-health/climate-and-people... [3] https://www.whoi.edu/press-room/news-release/climate-change-likely-caused-migration--demise-of-ancient-indus-valley-civilization/ https://www.whoi.edu/press-room/news-release/climate-change-...

bryanlarsen 4y ago
That sounds like Houston. Outside work is done in the early morning and outside play is done in the evening. During the middle of the day everybody stays inside in air conditioned buildings or vehicles. It's the wealth of Houston that makes this possible. Pakistan and India will adapt it as soon as they're wealthy enough. It'll come at a lower wealth point than Houston because their problem is more severe than Houston's.
- signal11 4y ago
  > That sounds like Houston. I think it's a little different. Houston by your account struggles in the afternoons today -- similar to parts of Spain and Portugal, but it's only at peak wet bulb ~75..76 F going by ASHRAE[1] data. Wet bulb 88 F is much worse, and 95 F is really when the human body gives up. Again, this is wet bulb, not air temperature. But if anyone has peak wet bulb data for major US cities, please share! It'd be an awesome resource. [1] American Society of Heating, Refrigerating and Air-Conditioning Engineers, https://www.ashrae.org/ https://www.ashrae.org/
FlyingSnake 4y ago
Citing Jacobabad as an example of upcoming wet bulb apocalypse is bit disingenuous IMO. It is one of the 2 hottest cities on the planet and routinely sees temperatures upto 52˚C. Maybe it is due to it's geographical location at the end of the Tharparkar desert and has a hot desert climate? Two things stand out from the article you shared. > it is an agricultural hub fed by irrigation canals. John Jacob used his civil engineering skills to build the Begaree canal which made this possible. It was an arid semi-desert landscape before that for centuries. > The region sits on the Tropic of Cancer, meaning the sun is close to overhead during the summer. So do Bikaner, Agra, Aligadh, Lucknow etc along with half of India, but they've never had a wet-bulb scenario in history like Jacobabad had. I will search for the data, but so far nothing comes up. I understand the threat of climate change is real , but I would love to see more data that supports this wet bulb theory in the subcontinent.
- signal11 4y ago
  Fair enough. Jacobabad is absolutely an edge case. The question is, is it just an outlier or are other places headed that way? Are the conditions that drive up wet bulb temps increasing, thanks to human activity? E.g. the number of Indian cities inching towards high 40s (Celsius) is climbing. Heck, New Delhi this year saw 49 C air temps, which was unheard of. But re wet bulb temps, the trend is troubling[1]. Plenty of Indian cities are crossing wet bulb > 31 C, which puts the elderly and infirm at risk when they're outside. Yes -- going from here to > 35 C is a big leap, but if you say it cannot happen that's ... a "hope for the best" mindset. Who knows, nothing might come out of it, but if the climate change models are correct, there's more pain ahead. Let's take a midpoint scenario between 'absolute best' and 'absolute worst' and assume summer wet bulbs increase slightly over time, not enough to breach 35 C. That's still temps in the 31...34 C range in major Indian cities, that basically makes it hell for the elderly and infirm. What are the social costs of that? Bear in mind, despite India's progress, it still has a fair number of people with limited means. And the number of elderly in India will grow over time as its "youth bulge" tapers off. [1] https://archive.ph/sPVL2 https://archive.ph/sPVL2

bryanlarsen 4y ago

That sounds like Houston. Outside work is done in the early morning and outside play is done in the evening. During the middle of the day everybody stays inside in air conditioned buildings or vehicles. It's the wealth of Houston that makes this possible. Pakistan and India will adapt it as soon as they're wealthy enough. It'll come at a lower wealth point than Houston because their problem is more severe than Houston's.

signal11 4y ago
> That sounds like Houston. I think it's a little different. Houston by your account struggles in the afternoons today -- similar to parts of Spain and Portugal, but it's only at peak wet bulb ~75..76 F going by ASHRAE[1] data. Wet bulb 88 F is much worse, and 95 F is really when the human body gives up. Again, this is wet bulb, not air temperature. But if anyone has peak wet bulb data for major US cities, please share! It'd be an awesome resource. [1] American Society of Heating, Refrigerating and Air-Conditioning Engineers, https://www.ashrae.org/ https://www.ashrae.org/

FlyingSnake 4y ago

Citing Jacobabad as an example of upcoming wet bulb apocalypse is bit disingenuous IMO. It is one of the 2 hottest cities on the planet and routinely sees temperatures upto 52˚C. Maybe it is due to it's geographical location at the end of the Tharparkar desert and has a hot desert climate? Two things stand out from the article you shared. > it is an agricultural hub fed by irrigation canals. John Jacob used his civil engineering skills to build the Begaree canal which made this possible. It was an arid semi-desert landscape before that for centuries. > The region sits on the Tropic of Cancer, meaning the sun is close to overhead during the summer. So do Bikaner, Agra, Aligadh, Lucknow etc along with half of India, but they've never had a wet-bulb scenario in history like Jacobabad had. I will search for the data, but so far nothing comes up. I understand the threat of climate change is real , but I would love to see more data that supports this wet bulb theory in the subcontinent.

signal11 4y ago
Fair enough. Jacobabad is absolutely an edge case. The question is, is it just an outlier or are other places headed that way? Are the conditions that drive up wet bulb temps increasing, thanks to human activity? E.g. the number of Indian cities inching towards high 40s (Celsius) is climbing. Heck, New Delhi this year saw 49 C air temps, which was unheard of. But re wet bulb temps, the trend is troubling[1]. Plenty of Indian cities are crossing wet bulb > 31 C, which puts the elderly and infirm at risk when they're outside. Yes -- going from here to > 35 C is a big leap, but if you say it cannot happen that's ... a "hope for the best" mindset. Who knows, nothing might come out of it, but if the climate change models are correct, there's more pain ahead. Let's take a midpoint scenario between 'absolute best' and 'absolute worst' and assume summer wet bulbs increase slightly over time, not enough to breach 35 C. That's still temps in the 31...34 C range in major Indian cities, that basically makes it hell for the elderly and infirm. What are the social costs of that? Bear in mind, despite India's progress, it still has a fair number of people with limited means. And the number of elderly in India will grow over time as its "youth bulge" tapers off. [1] https://archive.ph/sPVL2 https://archive.ph/sPVL2