
As our Abrupt Climate Change Catastrophe becomes more extreme the leading cause of death on the planet will be humans hitting their Wet Bulb Temperature.
“It has been widely believed that a 35°C wet-bulb temperature (equal to 95°F at 100% humidity or 115°F at 50% humidity) was the maximum a human could endure before they could no longer adequately regulate their body temperature, which would potentially cause heat stroke or death over a prolonged exposure.”
“Wet-bulb temperature is read by a thermometer with a wet wick over its bulb and is affected by humidity and air movement. It represents a humid temperature at which the air is saturated and holds as much moisture as it can in the form of water vapor; a person’s sweat will not evaporate at that skin temperature.”
“But in their new study, the researchers found that the actual maximum wet-bulb temperature is lower — about 31°C wet-bulb or 87°F at 100% humidity — even for young, healthy subjects. The temperature for older populations, who are more vulnerable to heat, is likely even lower.”
Humans can’t endure temperatures and humiditie’s as high and previously thought”
Short cut to calculating Wet Bulb Temperature
“In a recent study with Matt Huber, we showed that it doesn’t take that many degrees of global warming to permit peak heat summertime heat stress to (occasionally) become unsurvivable, in many parts of the world that are currently highly populated.”
“We came to this conclusion by considering a meteorological quantity called the wet-bulb temperature. You measure this quantity with a normal thermometer that has a damp cloth covering the bulb. It is always lower than the usual or “dry-bulb” temperature; how much lower depends on the humidity. At 100% humidity (in a cloud or fog) they match. In Sydney and Melbourne, even during the hottest weather, the wet-bulb usually peaks in the low 20’s C. The highest values in the world are about 30-31C, during the worst heat/humidity events in India, the Amazon, and a few other very humid places.
Climate Change Research Centre (CCRC) – The University of New South Wales Sydney NSW Australia, paper shared here: ‘What is Wet Bulb temperature?‘
Orange – Heat stroke probable, Red – Heat stroke imminent

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Via Sam Carana on Facadebook!
New research explores future limits of survival, livability in extreme heat conditions
ASU Associate Professor Jennifer Vanos models variables that shape livability under extreme heat conditions https://news.asu.edu/20231130-new-research-explores…
A physiological approach for assessing human survivability and liveability to heat in a changing climate – by Jennifer Vanos et al. https://www.nature.com/articles/s41467-023-43121-5
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Sam’s latest on high temps in the tropics, the humid tropics.
https://arctic-news.blogspot.com/2024/02/tragedy-set-to-unfold-in-tropics.html?fbclid=IwAR3ap8iIdSqFZuNFki0krESymF2c-Ob4Tko7VHRZlHt7qLTGWzYD8NEGMAY
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“The heat-associated deaths confirmed in 2023 represented a huge jump from 2022, when there were 425 such deaths. There were 339 heat-associated deaths confirmed in 2021.”
The death rate from heat waves going exponential like all of our other graphs.
https://www.theguardian.com/us-news/2024/mar/14/arizona-heat-deaths?CMP=twt_a-environment_b-gdneco&fbclid=IwAR3fj2LK04vihAxIZOtcMp-0MsOOg-FTMFyawrmTnsA6hIqCyRvswgxmhTI
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Sam Carana
Admin
· 9h ·
Tragedy set to unfold in Tropics (update)
Sam Carana
10h ·
TRAGEDY SET TO UNFOLD IN TROPICS (UPDATE)
Temperatures in the Tropics are rising rapidly. The image below shows the situation in the tropics (23.5°S-23.5°N, 0-360°E) through March 11, 2024, when the average daily surface air temperature was 26.7°C, i.e. 1.3°C above 1979-2000.
On April 24, 2016, it was 26.8°C, the highest temperature on record in the tropics and 1°C above 1979-2000, as the top image also shows.
The second image shows temperature anomalies over the past few years through February 2024.
Note that the anomalies in the above images are calculated from different bases. When calculated from a pre-industrial base, anomalies will be higher.
The danger is that tragedy will unfold over the next few months, as temperatures look set to exceed the 2016 peak in the tropics and cause widespread loss of life of people, livestock and wildlife, crop failure and ecosystem collapse in the tropics.
From the post ‘Tragedy set to unfold in Tropics (update)’, at:
https://arctic-news.blogspot.com/2024/03/tragedy-set-to-unfold-in-tropics-update.html?fbclid=IwAR2yUy9OPzxiVGSutFslRjbCgxX_GiJ1xg2-9pq3Ke_gKOHvSZOtQlEv3x8
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“A heatwave stifling Brazil has set new records with Rio de Janeiro’s heat index hitting 62.3 degrees Celsius (144.1 degrees Fahrenheit), the highest in a decade, weather authorities say.”
“The heat index measures what a temperature feels like by taking into account humidity. The actual maximum temperature in the city was 42C on Monday, the Rio Alert weather system said.”
https://www.aljazeera.com/gallery/2024/3/18/photos-record-heat-index-of-62-3c-scorches-rio-de-janeiro?fbclid=IwAR0tHmi-F4oyyl5fnq47pCMYPSzp77gqbhK5dY9ecwVnOinmvJyvu91sdyQ
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Soon, eh? Well, I guess it just became soon.
The Global South is getting hit…near the end of their summer in S. America. And it’s only March up here in the Northern Hemisphere but it hit 76’F yesterday.
So is this what we can expect by…Aug/Sept? A feel-like temperature of 140’F including wet bulb??? I’ve only experienced 120’F and it was barely survivable…and I don’t live in a humid climate as this is the dry side mountains of Washington State…
Besides, my mercury thermometer doesn’t go that high but then I guess it doesn’t matter as I barely made it outside once a day in the heat dome of 2021.
Brutal Heat Wave Packs Rio de Janeiro’s Beaches
https://weather.com/news/weather/video/brutal-heat-wave-packs-rio-de-janeiros-beaches
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sealinthe(soon to be burning again)Selkirks
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62C is what it feels like!
https://www.dailykos.com/stories/2024/3/18/2230156/-Rio-de-Janiero-hits-a-record-heat-index-of-144-1-F-62-3-C?pm_campaign=front_page&pm_source=trending&pm_medium=web&fbclid=IwAR2JllbS8HuiCAaSmJXZC-sJmgRZpmh-oslDM2Xj4OmPBPwTjlXoTXOyaNA
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This just popped up on the weather site. Uh-oh.
UN Weather Agency Issues ‘Red Alert’ For The Planet
https://weather.com/news/climate/video/un-weather-agency-issues-red-alert-for-the-planet
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sealintheSelkirks
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“The World Meteorological Organization’s “State of the Climate” report issued Tuesday has a stern warning for the planet – curb global warming or it will soon be too late.”
How quaint, it’s not too late!
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And this was posted today. Simple explanation in 40 seconds, scary reality:
Study: Temperatures Rising, But Heat Index Is Rising Faster
https://weather.com/news/climate/video/study-temperatures-rising-but-heat-index-is-rising-faster
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I find it interesting that weather.com is throwing up more ‘climate danger’ short vids than ever before. But since it has been between 70 and 76’F the last few days in these mountains, in freaking mid-March, best to be warning people about what is going to hit us up here this summer, yes?
Somehow, I don’t think many people are thinking about that around here yet. I sure the hell am.
sealintheSelkirks
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Via Sam Carana
Romps, Heat index extremes increasing several times faster than the air temperature, ERL, 2024
Climate Physics (berkeley.edu)
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“To estimate the impact of global warming on the heat index, we need to know how its two inputs—temperature and humidity—are changing. Any realistic change to the climate will alter mean diurnal cycles as well as distributions of daily-minimum and daily-maximum temperatures.”
Heat index extremes increasing several times faster than the air temperature – IOPscience
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[…] Stalling? CheckExtinction Cascades? CheckA Minimum of Six Dozen Feedback Loops Triggered? CheckLosing a city/region to extreme Wet Bulb Temps? […]
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Record-breaking heat and humidity predicted for tropics this summer
Combination of global warming and El Niño could lead to extreme humid heat stress.
Record-breaking heat and humidity predicted for tropics this summer | Berkeley
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Now we are seeing the extremely quick breakdown of El Nino that looks to turn instantly back to the La Nina pattern of the last three years by this summer. It’s only been El Nino over this winter, about 5-6 months is all! Holy hell, how did it zip completely past ‘climate neutral’ so damn quickly?
I’m getting ice Frisbees in the dog water pans most morning still, and back to 5’C temps by 10am up to maybe 12’C at best in the afternoons. Warmer in the sun of course, when it breaks through the clouds. Have had groppel coming out of some of the larger dark cloud masses drifting overhead, too, the last few days. Splatters of raindrops also of course but no real rain showers since last week. 1May and it’s acting like early April where in early March it was acting like early July with nearly 30’C temps. Happened three times total in March & April.
Wild damn swings in the weather up here by Canada.
Fires are going above the border, too. And have seen a few of the wildfire water bombers heading west over the Columbia River but no smoke smell detected by nose nor visible in the air here yet. I have a bad feeling about this summer, dude.
La Nina has pounded us with heat the last three years as it has Canada. Every June it has been over 40’C by the second week, and up to near 50’C by the end of the month (2021). Then it stays that way right into November!
Washington State just declared drought conditions last week…snowpack levels have disappeared and especially bad here in the NE corner mountains. What little we had is just…gone. Not much of a Spring run-off that I noticed. Local rivers and streams never really went into what I’d call flood stage.
I posted that article about Mexico’s ongoing heat and drought on a different thread but it certainly applies here, too.
sealintheSelkirks
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Heatwave in Asia: How to cope with extremely hot weather? | DW News Desk (youtube.com)
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Temperatures in the Tropics
The temperature in the Tropics (23.5°S-23.5°N, 0-360°E) remained very high during the first part of May 24, 2024.
Arctic News: Temperatures in the Tropics (arctic-news.blogspot.com)
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It’s the hottest May ever in Miami. Heat index ‘completely off the charts’
Read more at: https://www.miamiherald.com/news/local/environment/climate-change/article288594929.html#storylink=cpy
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Howler Monkeys Dropping Dead from Heat and High Humidity and Lack of Water in Mexico Paul Beckwith
https://www.youtube.com/watch?v=uzSaHrzkgDo
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Abstract
“The recent concurrence of electrical grid failure events in time with extreme temperatures is compounding the population health risks of extreme weather episodes. Here, we combine simulated heat exposure data during historical heat wave events in three large U.S. cities to assess the degree to which heat-related mortality and morbidity change in response to a concurrent electrical grid failure event.”
https://pubs.acs.org/doi/10.1021/acs.est.2c09588?fbclid=IwZXh0bgNhZW0CMTEAAR1935v39p8jnaTMxqAPEE5_KakbWg3co_8Qxmd2U2elZeA3Szo_tJG_d88_aem_ARHBQWaYIvlwRc1ie1TcTlmtoz9_1Jds9Yy7GACIg1Wl-wymubOKRgYYwjo2OPM0hgK3wuOfwcdrN5dftJAq5WGE
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Mix this into the Wet Bulb and we truly do get Climate Hell. Part of me is saying ‘Oh HELL no’ while the calmer part of my mind is nodding its head:
Warning of ‘climate hell’ after 12 hottest months on record | REUTERS
https://www.youtube.com/watch?v=LENTeLb-fUo
Last sentence from the German guy….”from now on it will be worse” even if we could completely stop the increased loading of GHGs into the atmosphere? His thoughts that maybe by the end of the century the temps will go down to where they are now IF we could do that???
WTF is he talking about?
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A bunch of tornadoes just ran into Maryland on the US East Coast, two or more ran through the same town. Kind of makes a mockery of the term ‘Tornado Alley’ for the lower Midwest but the warning was recently given that it looked like the general track of these kind of storms are moving further east into the more populated areas… Don’t see coastal states having tornado damage very often even if it was inland from the Atlantic.
Will probably hear from that long-time climate watching friend in Baltimore about this one today. It’s hurricane season for him now, too.
Last month was the 12th month straight of record monthly heat. A full freaking year, dude. Think this summer with La Nina setting back up is really going to make a difference especially with the worldwide ocean being so hot?
May was 12th month in a row of record-breaking heat: EU climate monitor
https://www.youtube.com/watch?v=YNYXVeE5NAA
sealintheSelkirks
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Arctic news
Sam Carana ·
Favourites · 2h ·
New features at nullschool: wet bulb and dew point temperatures
https://news.nullschool.net/…/new-features-wet-bulb-and…
As an example, wet-bulb temperatures as high as 28.4°C or 83.0°F were reached in India on June 1, 2024.
https://earth.nullschool.net/…
Wet-bulb temperature calculator
https://www.weather.gov/epz/wxcalc_dewpoint
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Via the tireless Sam Carana
HIGH WET BULB GLOBE TEMPERATURE DANGER
Wet Bulb Globe Temperature (WBGT) takes into account the effect of temperature, RH (relative humidity), wind speed, and solar radiation.
WBGT is used by weather.gov to warn about extreme heat stress when in direct sunlight, as is forecast to occur in grey areas on July 26, 2024 at 21 UTC.
The inset shows that a temperature of 113°F or 45°C and a Wet Bulb Globe Temperature of 95°F or 35°C is forecast for a location 8 miles south of Parker, Arizona, on July 26, 2024 at 21 UTC.
The map illustrates that extreme heat stress can occur at higher latitudes, e.g. the grey areas in the north of the United States that extend into Canada. The danger occurs where high temperatures coincide with high relative humidity.
From the post ‘High Wet Bulb Globe Temperature Danger’, at:
Arctic News: High Wet Bulb Globe Temperature Danger (arctic-news.blogspot.com)
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The only temperature limit I know of that is going down.
Our predicament is always worse than we knew, yesterday
Humans have a much lower heat tolerance than expected – Earth.com
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Robert Hunziker’s latest covering Insurance and wet bulb temps.
https://www.pressenza.com/2025/06/swiss-re-sonar-2025-report-global-heat-kills-480000-yr/
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Look what’s about to happen to the US…in mid-June:
Dangerous Heat Wave To Set Record Highs
https://weather.com/forecast/regional/video/heat-wave-northeast-extreme-heat-warning
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And for some strange reason the temp here today never went above 64’F, same expected tomorrow, but back into the 80s/25-27C this coming week.
Going to be a very long hot summer. Can’t wait for the first hurricanes to impact the Deep South since Trump just cut another 150 million from Florida’s flood grants before he bombed Iran today….
Ain’t life full of surprises?
sealintheSelkirks
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How come no one warned us?
Week of sweltering US heat – is this the new normal in a warming world? | Climate crisis | The Guardian
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But but but…there has been numerous people warning the entire fucking world that this was coming. For fucking decades.
Oh wait, it was always the WRONG people and who would listen to them? The enviro-freaks, those damnable climate alarmists, the morons who think a livable temperature is worth more than a bank account full of fossil fuel dividends. And a lot of these same people think a bunch of froo-frooo science crap out of a book is more real that our Savior’s book The Bible that of course only speaks the truth…
And who really believed that little wimpy guy who stood up in front of the US Congress in 1988 and gave warning? I mean, a NASA egghead don’t know shit!
And Carl Sagan was a weirdo, too! He didn’t realize just how important nuclear bombs are for our peace and prosperity like our Dear Leader Dementia Don the Dictator who rules so benevolently since he’s only getting rid of the ‘vermin’ so delicately put in his wonderful way of use the English language. Just like another nice guy named Adolf that was so misunderstood back in the 1930s & 40s.
Believe in our lord jeezus and drill baby drill and you will be saved!
Unless, of course, you are one of those 80 bodies (so far) recovered from the Texas hill country flood of the 4th of July. All those dead Christian Camp girls taken by jeezus but it was probably all Biden’s fault in the first place. Or maybe those abortionists… Hard to tell where to lay the blame sometimes, ya know? Can’t blame our Dear Leader who fired a couple thousand weather weenies then de-funded and closed local offices who failed to give warning…
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And the US has had its first Tropical Storm roaring in to the North Carolina on the East Coast. That’s a bit early, eh? But hey, more CO2 means greener fields!
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Oh, now this is funny that just popped up:
The Texas flood just rescued two young girls alive in a tree…27 feet up! So there was a comment below the article/video that said:
“Thank you Jesus, for saving those two girls.” And the next comment replying said:
“Thank you Jesus, for sending the flood.”
Ahahahahaha!
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On that note, I leave you with one from Dark Brandon about the people who think there ain’t no such beast as climate destabilization:
Texas Floods Were FAKE! MAGA Prepper vs. Science
https://www.youtube.com/watch?v=AkWkv80bqA0
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sealintheSelkirks
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Brilliant response, in a nutshell
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Arctic news
Sam Carana ·
Favourites · 12h · When Will Extreme Heat Become Unlivable?
Season 6 Episode 10 | In this episode of Weathered, we break down: What wet-bulb temperature actually means. https://www.pbs.org/…/when-will-extreme-heat-become…
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Brutal, deadly etc
Europe Heatwave | Why Is Europe Hitting 46°c And Still Rising? | Europe Weather | 4K Video | N18G
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Key takeaways
Researchers led by UCLA and the Universidad Adolfo Ibañez in Santiago, Chile, developed an equation that has the flexibility to analyze one region or to gain additional broad insight by analyzing multiple regions as a whole.
Heat wave duration is accelerating faster than global warming | UCLA
Each fraction of a degree of warming will have a bigger impact than the last on lengthening heat waves, with the most extreme heat waves lengthening the most.
Tropical regions will see larger changes than temperate regions, and summer heat waves will lengthen more than winter warm spells.
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One correction I’ll make is the latest science is that a Wet Bulb temperature of 31C can be fatal
Cold Kills More than Heat. But is it True? – by Ugo Bardi
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Cooking with Radio Ecoshock!
HEAT STORM! How it kills and who. (replay) by RadioEcoshock
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[…] we discussed having to update my blog post when the Wet Bulb Rubicon could be crossed over at 31C. Wet Bulb Temperature Soon to Become Leading Cause of DeathI mentioned the Iranian government sending non-essential workers home to avoid heat stress, the […]
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Sam Carana
EXTREME HEAT STRESS WARNING
A 96°F or 36°C temperature is forecast for a location near Jackson, Mississippi, US, on July 30, 2025, 18:00 UTC. At a relative humidity of 64%, this corresponds with a wet bulb globe temperature of 94°F or 34°C and a ‘feels like’ temperature of 121°F or 49°C.
The forecast illustrates the huge difference that a higher relative humidity percentage can make.
Arctic News: Heat Stress in the US
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Thermometer read 105’F/40’C today at 4:20pm when I took the dogs out to go pee. Humidity was 22%. Both needed out and both immediately afterwards headed for the shade of the apple tree to roll in the cool tall grass I leave growing underneath, but the old girl Golden Retriever went back up on the porch and waited for the door while the younger girl Husky did a bit more rolling before she jumped up and wanted in, too.
It was too freaking hot in these mountains…and it’s not even August yet. Oh my.
An 8,000 acre fire is burning about 40 miles the north of me (between Kettle Falls and the Canadian Border) with a thousand firefighters on it in extremely rough mountainous terrain while a smaller one is burning 40 miles to the south of me at Long Lake west of Spokane. A third fire is in the Columbia River s/w of me on the Oregon side where my neighbor is driving a gray water tanker for the fire camp showers and handwashing stations… I’m actually not in smoke at the moment.
But it was fucking hot today, no doubt about that. It was 90’F at 11am….but fuck the slave states that all voted for Trump. Let them suffer what Trump is going to do to his ‘base’ whom he cares not whether they live or die.
Why do I feel this way? Watch this and hear the reality:
This guy really lays out the MAGA view of the world and why they absolutely thrive on hate. And he listened George Carlin musing…
Maga Politician Says She ENJOYS Watching THIS On YouTube
sealintheSelkirks
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Many thanks for those reports from your part of the world, I appreciate all anecdotal observations from trusted sources like Seal.
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Sam Carana
EXTREME HEAT STRESS WARNING
(Forecast for July 31, 2025)
A 102°F or 39°C temperature is forecast for a location near Texarkana, Arkansas, US, on July 31, 2025, 18:00 UTC. At a relative humidity of 47%, this corresponds with a wet bulb globe temperature of 94°F or 34°C and a ‘feels like’ temperature of 119°F or 48°C.
From the post ‘Heat Stress in the US’, at:
Arctic News: Heat Stress in the US
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As a counterpoint to this, I offer you this article:
Troubling scenes from an Arctic in full-tilt crisis
https://grist.org/climate/troubling-scenes-from-an-arctic-in-full-tilt-crisis/
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I asked myself, when I first read about this ‘seed vault’ being built in permafrost and extremely close to the ocean, “But what if the permafrost melts and the ocean rises like a number of scientists are saying is going to happen?”
Damn.
sealintheSelkirks
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A 43% increase in heat-related deaths in just the past two years?
Boy is that sure going to skyrocket, eh?
https://weather.com/health/video/heat-related-illness-what-to-know-as-temps-spike
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103’F today at 3pm. The dogs are inside as I am…fuck this shit and I have a couple months of this left. At least! I used to always count on the first frost the first week in September. ALWAYS according to my retired biologist neighbor who has saved calendar records going back over 50 years.
At least it is still cooling down at night in these mountains. By midnight the house windows are open. That may change this month, like it did last year…
sealintheSelkirks
sealintheSelkirks
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Guy’s latest detailing more people are dying from heatwaves than war, some irony there considering that war fuels heatwaves.
Extreme Heat Kills More People Than Military Conflicts
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Considering how many wars we have raging on the planet, it seems incongruous that simple heat could be killing more people than high velocity lead, depleted uranium munitions and everything between.
Let’s not forget that a lot of this heat is a result of military emissions.
Abby Martin has just released a feature film Earth’s Greatest Enemy – A New Film by Abby Martin. Abby has her sights firmly on the imperialist US military machine that I have written about in my article titled, “Warmongering and the Climate Crisis.”
A sector that has been hard hit due to workers exceeding their Wet Bulb limits is those people planting, weeding and harvesting our crops. Working outdoors during a heat wave can be and is lethal.
One final note, the wild animals have no aircon to use to hide from extreme heat, hence stories like bats in Australia falling out of trees from heat stress.
Warmongering and the Climate Crisis | Kevin Hester
(10) Extreme Heat Kills More People Than Military Conflicts
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Who will harvest our crops when the workers succumb to kidney failure?
Heat Stress Is a Major Driver of India’s Kidney Disease Epidemic – Yale E360
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