Johnny Carson of the Tonight Show used to do a schtick called “The Edge of Wetness” which was a parody of a soap opera called “The Edge of Night”
It was he first thing that went through my mind after reading this press release citing a new worry about wet bulb temperature. Apparently it’s not just the heat, but the humidity too.
Researchers find future temperatures could exceed livable limits
This map shows the maximum wet-bulb temperatures reached in a climate model from a high carbon dioxide emissions future climate scenario with a global-mean temperature 12 degrees Celsius (21 degrees Fahrenheit) warmer than 2007. The white land areas exceed the wet-bulb limit at which researchers calculated humans would experience a potentially lethal level of heat stress. (Purdue University graphic/Matthew Huber)
WEST LAFAYETTE, Ind. – Reasonable worst-case scenarios for global warming could lead to deadly temperatures for humans in coming centuries, according to research findings from Purdue University and the University of New South Wales, Australia.
Researchers for the first time have calculated the highest tolerable “wet-bulb” temperature and found that this temperature could be exceeded for the first time in human history in future climate scenarios if greenhouse gas emissions continue at their current rate.
Wet-bulb temperature is equivalent to what is felt when wet skin is exposed to moving air. It includes temperature and atmospheric humidity and is measured by covering a standard thermometer bulb with a wetted cloth and fully ventilating it.
The researchers calculated that humans and most mammals, which have internal body temperatures near 98.6 degrees Fahrenheit, will experience a potentially lethal level of heat stress at wet-bulb temperature above 95 degrees sustained for six hours or more, said Matthew Huber, the Purdue professor of earth and atmospheric sciences who co-authored the paper that will be published in Thursday’s (May 6) issue of the Proceedings of the National Academy of Sciences.
“Although areas of the world regularly see temperatures above 100 degrees, really high wet-bulb temperatures are rare,” Huber said. “This is because the hottest areas normally have low humidity, like the ‘dry heat’ referred to in Arizona. When it is dry, we are able to cool our bodies through perspiration and can remain fairly comfortable. The highest wet-bulb temperatures ever recorded were in places like Saudi Arabia near the coast where winds occasionally bring extremely hot, humid ocean air over hot land leading to unbearably stifling conditions, which fortunately are short-lived today.”
The study did not provide new evaluations of the likelihood of future climate scenarios, but explored the impacts of warming. The challenges presented by the future climate scenarios are daunting in their scale and severity, he said.
“Whole countries would intermittently be subject to severe heat stress requiring large-scale adaptation efforts,” Huber said. “One can imagine that such efforts, for example the wider adoption of air conditioning, would cause the power requirements to soar, and the affordability of such approaches is in question for much of the Third World that would bear the brunt of these impacts. In addition, the livestock on which we rely would still be exposed, and it would make any form of outside work hazardous.”
While the Intergovernmental Panel on Climate Change central estimates of business-as-usual warming by 2100 are seven degrees Fahrenheit, eventual warming of 25 degrees is feasible, he said.
“We found that a warming of 12 degrees Fahrenheit would cause some areas of the world to surpass the wet-bulb temperature limit, and a 21-degree warming would put half of the world’s population in an uninhabitable environment,” Huber said. “When it comes to evaluating the risk of carbon emissions, such worst-case scenarios need to be taken into account. It’s the difference between a game of roulette and playing Russian roulette with a pistol. Sometimes the stakes are too high, even if there is only a small chance of losing.”
Steven Sherwood, the professor at the Climate Change Research Centre at the University of New South Wales, Australia, who is the paper’s lead author, said prolonged wet-bulb temperatures above 95 degrees would be intolerable after a matter of hours.
“The wet-bulb limit is basically the point at which one would overheat even if they were naked in the shade, soaking wet and standing in front of a large fan,” Sherwood said. “Although we are very unlikely to reach such temperatures this century, they could happen in the next.”
Humans at rest generate about 100 watts of energy from metabolic activity. Wet-bulb temperature estimates provide upper limits on the ability of people to cool themselves by sweating and otherwise dissipating this heat, he said. In order for the heat dissipation process to work, the surrounding air must be cooler than the skin, which must be cooler than the core body temperature. The cooler skin is then able to absorb excess heat from the core and release it into the environment. If the wet-bulb temperature is warmer than the temperature of the skin, metabolic heat cannot be released and potentially dangerous overheating can ensue depending on the magnitude and duration of the heat stress.
The National Science Foundation-funded research investigated the long-term implications of sustained greenhouse gas emissions on climate extremes. The team used climate models to compare the peak wet-bulb temperatures to the global temperatures for various climate simulations and found that the peak wet-bulb temperature rises approximately 1 degree Centigrade for every degree Centigrade increase in tropical mean temperature.
Huber did the climate modeling on supercomputers operated by Information Technology at Purdue (ITaP), Purdue’s central information technology organization. Sherwood performed the wet-bulb calculations.
“These temperatures haven’t been seen during the existence of hominids, but they did occur about 50 million years ago, and it is a legitimate possibility that the Earth could see such temperatures again,” Huber said. “If we consider these worst-case scenarios early enough, perhaps we can do something to address the risk through mitigation or new technological advancements that will allow us to adapt.”
Writers: Elizabeth K. Gardner, 765-494-2081, ekgardner@purdue.edu
Greg Kline, 765-494-8167, gkline@purdue.edu
Sources: Matthew Huber, 765-494-9531, huberm@purdue.edu
Steven Sherwood, +61 (2) 9385 8960, s.sherwood@unsw.edu.au
Related Web site:
Matthew Huber’s Climate Dynamics Prediction Laboratory
ABSTRACT
An Adaptability Limit to Climate Change Due to Heat Stress
Steven C. Sherwood, Matthew Huber
Despite the uncertainty in future climate change impacts, it is often assumed that humans would be able to adapt to any possible warming. Here we argue that heat stress imposes a robust upper limit to such adaptation. Peak heat stress, quantified by the wet-bulb temperature Tw, is surprisingly similar across diverse climates today. Tw never exceeds 31C. Any exceedence of 35C for extended periods should induce hyperthermia in humans and other mammals, as dissipation of metabolic heat becomes impossible. While this never happens now, it would begin to occur with global-mean warming of about 7C, calling the habitability of some regions into question. With 11-12C warming, such regions would spread to encompass the majority of the human population as currently distributed. Eventual warmings of 12C are possible from fossil fuel burning. One implication is that recent estimates of the costs of unmitigated climate change are too low unless the range of possible warming can somehow be narrowed. Heat stress also may help explain trends in the mammalian fossil record.
What’s scary is not that this is a scenario birthed within an academic environment and proposed as a serious possibility. No, what’s scary is that no one turned to the originator(s) of this proposal and said, “Hey, you do know you are certifiably nuts?” And then think of how many smart people encouraged this effort — and paid for it. Obviously again, we see hysterics have gone mainstream.
There’s a group of people who exceed their purported “highest tolerable wet-bulb temperature” for extended durations on a daily basis. They are the soldiers, sailors, and airmen who toiled, with often extreme exertion, in full body armor in the summer heat in the river valleys and deserts of Iraq. I would hazard a guess that the protective gear, long sleeves and trousers guaranteed that they spent a lot of time well above the limits described in the article. Not being able to dress the same way as the locals, their heat stress index numbers would be way higher than that of the people who grew up under those conditions. Yeah, there were heat casualties, but those were not anywhere close to the scale touted in the article.
The authors failed to address the long-demonstrated capacity for homo sapiens to adapt to environmental conditions, be they extreme cold or extreme heat and humidity.
The fact that this paper will be published in the Proceedings of the National Academy of Sciences does not reflect well on the NAS. Not even a little bit. Can we say peer review failure? Sure we can.
@ur momisugly rbateman (May 4, 2010 at 10:21 pm)
It may not be fair to compare current conditions with what the soothsayers prognosticate for the distant future, but in just 7 weeks the days will start getting shorter again and where I live in Idaho, the forcase low for tomorrow night (one of the few I give any credibility at all) is for 24 degrees F. Our leaves are only half out and our trees could be frost stunted with this–it happened a few decades ago and for that entire summer, the leaves were small and never did grow to full size. Currently whatever fruit is in blossom or even in bugs will be destroyed with this cold weather.
This is in stark contrast to what these “climate scientists” are predicting and my fears are based on what I observe. But you can see their dire need to eliminate the existance of the MWP, since our ancestors survived that period of a warmer earth and even thrived. But “thrived” isn’t allowed in a Warmer’s vocabulary; only scare-mongering and fantasy.
Oops…”forecast”, not “forcase”, and “buds”, not “bugs”….
Totally insane,
According to widely available data, this earth has never had a mean global Temperature that is 12 deg C higher than the present level of about 288 K, anytime in the last 600 million years !
So who funded this moronic research ?
“The study did not provide new evaluations of the likelihood of future climate scenarios, but explored the impacts of warming. ”
So basically the study showed that if it it gets really hot………then it will get really hot.
Two inches of snow this a.m. in La Grande, Ne-Oregon. Arizona CJ-this country is much like Northern Az. Especially the Mogollon Rim., and Flagstaff. Not quite as high though. That said, We’ve had a cold, nasty spring. Been afraid to plant tender stuff as I’ve already zorched a hardy Lilac, and somewhat tender Rose.
Cold Kills not warm. Someone got some grant money….
I wonder who paid for this garbage?
Does this mean we will not grow gills either?
Like Kevin Costner in “Waterworld”.
This is surely shocking news and excellent science.
Yet another computer model based “crisis?” I’m reminded of a TV series where the leading character would say “Well then, would you believe…” I think that these “scientists” are probably affecting average citizens the same way.
Could someone point me to historic wet bulb data for North East Texas (or Houston)? Several years ago, we experienced over 30 days in a row of 100 deg. F (or higher) dry bulb temperatures and it’s usually pretty humid here. I’m just trying to figure out if we should have all been dead if we experienced “a potentially lethal level of heat stress at wet-bulb temperature above 95 degrees sustained for six hours or more”. Or maybe we have become acclimated…….
When I was in the Army, they had guidelines on working in a variety of WBGT (wet bulb globe temperature(s)). See https://docs.google.com/viewer?url=http://chppm-www.apgea.army.mil/doem/pgm34/HIPP/HeatRiskManGuideMar04.pdf . From what I recall, they don’t say that death is imminent, they just say you need to follow their guidelines to make sure you reduce/minimize the potential for heat injuries.
The University of NSW has serious issues regarding climate change.
These people should be ashamed of themselves!!
http://www.ccrc.unsw.edu.au/staff/academic.html
I guess none of these researchers have ever been to Orlando Florida in August. This is a proof principle of survival under the most extreme humidity conditions.
I have prepared a “worst case” model as well. In this worst case, all the melting ice causes the crust to HEAVE upward, shooting some people into outer space.
Then, the crust will give way, and lava will be ejected everywhere. The surface of earth will turn into a boiling cauldron with a temperature of a Trillion degrees. (I checked with Al on the final calculations)
There is only 85% certainty of this outcome. There is still a chance to save mankind if we act NOW. Take only direct flights, recycle, and buy a cloth bag for your groceries.
This is what they produced last December
http://www.copenhagendiagnosis.org/press.html
..blah..blah… robust (takes a drink)
..blah..blah… warmings of 12C (takes a drink)
..blah..blah… Reasonable worst-case scenarios (takes a drink)
..blah..blah… warming of 25 degrees is feasible (takes a drink)
..blah..blah… climate modeling on supercomputers (takes a drink)
..blah..blah… While this never happens now, it would begin to occur (takes a drink)
Wow, this new alarmist drinking game sure makes me dizzy…
During the extremely warm periods of the early Eocene, the equator-near areas were actually cooler than now (the polar/equator temperatur difference was much smaller than now). I wonder why they assume their hypothetical future earth will be significantly different from earlier warm periods?
The early Eocene was wonderful for mammals and land plants (most of the earth was covered with forests). Only some ocean bottom-dwelling simple organisms had a hard time.
I wonder if anyone has developed a computer model that can accurately predict just how stupid you need to be to believe anything coming from climate research organizations anymore.
I’m sorry, but you have all fallen for it. This is a spoof article written by a young student by the name of Huber who passed it on to Al Gore. He took it seriously and released it to the press. The student I understand has been expelled from his college for wasting his time, but has been given a job by the IPCC as they will be including his article in their next report to the U.N. now that it has been peer reviewed. They stated that the computer model could not possibly be wrong.
I used to work at a UPS hub loading boxes by hand into their semi trailers. In June one year, it was 98 outside and incredibly humid. Inside the trucks, which had been left to bake in the sun until 4pm with the doors shut, it had to have been 130. You would begin sweating just from walking into the truck, before ever touching a single parcel. We loaded about 400-600/hr at an average weight of 30 pounds, it was very physical work. In 120-130F trucks. I am obviously still alive.
Please, bring on the GW, any kind, they’re predicting snow here for tonight. Salt Lake area…on May 5-6. I’m trying to cycle.
On May 4, Mike McMillan said: …”when we bbq brisket.” Is that Mike R (rocky66) McMillan?
JKL
R. de Haan 6:20 am
“too much time smoking pot in the sauna!”
I think we should force all climate scientologists to smoke large quantities of pot in a sauna. That way, they would be so busy laughing at themselves for this type of drivel that “research” like this would never actually be submitted for publication. “Dude, we can’t submit this. If we do, they’ll KNOW we are high! Hey, who bogarted all my Doritos?!?!?”
What a world we live in! Apparently, we won’t have to worry about it for too much longer.
After a good night’s sleep I have given this some sober thought. This press release is not real. It is the test plot for a science fiction movie. Perhaps these armature fiction authors should stick to something they know at lest something about. I wonder if they could do better at pornography?
What is obvious is that college professors have entirely too much time on their hands. The finding for grants (paid for by taxpayers) should be substantially be reduced. The government organization which determines which grants are approved should also be taken to task. After a ridiculous “study” conclusion such as this one, the professor should be placed on a black list, whereby not only would the professor be forbidden future grants, but any grant proposals where the grant proposal included this professor’s participation in any way should be rejected.
If you are to have a decent garden, the weeds have to be removed. As it is, the garden of government paid grants is over-run with weeds such as this. Perhaps Hollywood would be willing to pay professors such as this one to write fantasy doomsday stories, but we taxpayers certainly shouldn’t be forced to do so.
…could lead to deadly temperatures…
…could be exceeded…
…did not provide new evaluations of the likelihood of future climate scenarios…
Very convincing stuff. I could be up to twelve feet tall. There could be a monster under your bed. We could have another Ice Age soon.