Current trend of “global warming” isn’t enough to get there, says MIT scientist.
How Earth sheds heat into space
New insights into the role of water vapor may help researchers predict how the planet will respond to warming.
Just as an oven gives off more heat to the surrounding kitchen as its internal temperature rises, the Earth sheds more heat into space as its surface warms up. Since the 1950s, scientists have observed a surprisingly straightforward, linear relationship between the Earth’s surface temperature and its outgoing heat.
But the Earth is an incredibly messy system, with many complicated, interacting parts that can affect this process. Scientists have thus found it difficult to explain why this relationship between surface temperature and outgoing heat is so simple and linear. Finding an explanation could help climate scientists model the effects of climate change.
Now scientists from MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) have found the answer, along with a prediction for when this linear relationship will break down.
They observed that Earth emits heat to space from the planet’s surface as well as from the atmosphere. As both heat up, say by the addition of carbon dioxide, the air holds more water vapor, which in turn acts to trap more heat in the atmosphere. This strengthening of Earth’s greenhouse effect is known as water vapor feedback. Crucially, the team found that the water vapor feedback is just sufficient to cancel out the rate at which the warmer atmosphere emits more heat into space.
The overall change in Earth’s emitted heat thus only depends on the surface. In turn, the emission of heat from Earth’s surface to space is a simple function of temperature, leading to to the observed linear relationship.
Their findings, which appear today in the Proceedings of the National Academy of Sciences, may also help to explain how extreme, hothouse climates in Earth’s ancient past unfolded. The paper’s co-authors are EAPS postdoc Daniel Koll and Tim Cronin, the Kerr-McGee Career Development Assistant Professor in EAPS.
A window for heat
In their search for an explanation, the team built a radiation code — essentially, a model of the Earth and how it emits heat, or infrared radiation, into space. The code simulates the Earth as a vertical column, starting from the ground, up through the atmosphere, and finally into space. Koll can input a surface temperature into the column, and the code calculates the amount of radiation that escapes through the entire column and into space.
The team can then turn the temperature knob up and down to see how different surface temperatures would affect the outgoing heat. When they plotted their data, they observed a straight line — a linear relationship between surface temperature and outgoing heat, in line with many previous works, and over a range of 60 kelvins, or 108 degrees Fahrenheit.
“So the radiation code gave us what Earth actually does,” Koll says. “Then I started digging into this code, which is a lump of physics smashed together, to see which of these physics is actually responsible for this relationship.”
To do this, the team programmed into their code various effects in the atmosphere, such as convection, and humidity, or water vapor, and turned these knobs up and down to see how they in turn would affect the Earth’s outgoing infrared radiation.
“We needed to break up the whole spectrum of infrared radiation into about 350,000 spectral intervals, because not all infrared is equal,” Koll says.
He explains that, while water vapor does absorb heat, or infrared radiation, it doesn’t absorb it indiscriminately, but at wavelengths that are incredibly specific, so much so that the team had to split the infrared spectrum into 350,000 wavelengths just to see exactly which wavelengths were absorbed by water vapor.
In the end, the researchers observed that as the Earth’s surface temperature gets hotter, it essentially wants to shed more heat into space. But at the same time, water vapor builds up, and acts to absorb and trap heat at certain wavelengths, creating a greenhouse effect that prevents a fraction of heat from escaping.
“It’s like there’s a window, through which a river of radiation can flow to space,” Koll says. “The river flows faster and faster as you make things hotter, but the window gets smaller, because the greenhouse effect is trapping a lot of that radiation and preventing it from escaping.”
Koll says this greenhouse effect explains why the heat that does escape into space is directly related to the surface temperature, as the increase in heat emitted by the atmosphere is cancelled out by the increased absorption from water vapor.
Tipping towards Venus
The team found this linear relationship breaks down when Earth’s global average surface temperatures go much beyond 300 K, or 80 F. In such a scenario, it would be much more difficult for the Earth to shed heat at roughly the same rate as its surface warms. For now, that number is hovering around 285 K, or 53 F.
“It means we’re still good now, but if the Earth becomes much hotter, then we could be in for a nonlinear world, where stuff could get much more complicated,” Koll says.
To give an idea of what such a nonlinear world might look like, he invokes Venus — a planet that many scientists believe started out as a world similar to Earth, though much closer to the sun.
“Some time in the past, we think its atmosphere had a lot of water vapor, and the greenhouse effect would’ve become so strong that this window region closed off, and nothing could get out anymore, and then you get runaway heating,” Koll says.
“In which case the whole planet gets so hot that oceans start to boil off, nasty things start to happen, and you transform from an Earth-like world to what Venus is today.”
For Earth, Koll calculates that such a runaway effect wouldn’t kick in until global average temperatures reach about 340 K, or 152 F.
Global warming alone is insufficient to cause such warming, but other climatic changes, such as Earth’s warming over billions of years due to the sun’s natural evolution, could push Earth towards this limit, “at which point, we would turn into Venus.”
Koll says the team’s results may help to improve climate model predictions. They also may be useful in understanding how ancient hot climates on Earth unfolded.
“If you were living on Earth 60 million years ago, it was a much hotter, wacky world, with no ice at the pole caps, and palm trees and crocodiles in what’s now Wyoming,” Koll says. “One of the things we show is, once you push to really hot climates like that, which we know happened in the past, things get much more complicated.”
This research was funded, in part, by the National Science Foundation, and the James S. McDonnell Foundation.
NOTE: Try as I might, I could not locate the paper by press time. In its press release, MIT failed to include a link to the paper, DOI, or title of paper….anything that could possibly help find it at PNAS. Journalism 101 failure.
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At a world average surface temperature of 152 °F we wouldn’t need to worry about life as most of it will have died. That’s 152 °F average temperature.
My take is they are saying there cannot be runaway warming until the Earth’s average temperature rises above 152 degrees F., not that we are headed there.
Everything else they said and everything we already know means it would be impossible for the Earth’s average temp to rise to anything even close to that temperature.
So, that’s one less thing (runaway warming) we have to worry about.
SR
Which is why we call it the ‘Goldilocks Zone’… just nice and stable enough.
PS I really dislike needing to renter my name 🙁
As you can see above my fingers are too fat.
I was wondering if it was only me or if it was my browser settings or what. Yes, very annoying. The same thing has occurred at Tony Heller’s site…I have to re-enter my name and email every time I make a new comment. This was never the case for all of the years I have been visiting these sites.
It is very annoying.
It is also infuriating how one time you can direct link images and videos and the next time you cannot. The previous version of WordPress actually worked properly all the time. Now you have numerous faults and glitches which remain unfixed after months. This constant demand to keep entering your details before every post is the least of it.
menicholas,for those from the uk could this be something to do with the gdpr legislation ? there is a whole host of stuff from the states i seem to be no longer able to access.
So with no CAGW possible what do we have to worry about? I am sure Mann is organizing his team right now to trash the study.
I don’t see any reason why to take this model any more seriously than any other one.
From the lame description in the PR written by someone who does not understand it, this appears to be a one dimensional model , so how did they include convention in the model. They must have just added an ad hoc parameter for convective heat flow because you can not model convection is 1D. Neither can they model tropical to pole heat transfers or ocean circulation. This kind of model will tell you nothing about how a spherical climate system works.
What kind of air column were they modelling ? A tropical one, temperate or polar. They are very different and will respond differently to changes in surface temps.
The idea of a 1D earth model’s single temp of the Earth surface layer having any relation to the real temperatures of different media ( sea and land ) averaged around the globe is stupid.
Since they are too stupid to even link to the paper they are supposed to be promoting, I don’t have much hope of this being any use to anyone.
The wide range of comments on this thread mean that it is going to be a keeper for me and this is before most of us have read the published paper!
Interesting issue raised by Greg:-
“this appears to be a one dimensional model” & “you can not model convection (in) 1D”. (Greg; Sep24 10:47pm). I totally agree, in my opinion the minimum model possible has to be two dimensional. All planets are globes and in a solar system like ours with only one sun, planets, moons, comets, rocks, dust etc. will all have a lit side and an unlit side. Two separate states of external illumination always exist; therefore two dimensional models are required.
The argument that outgoing thermal radiation can be modelled one dimensionally because the radiation is being averaged over the surface of the whole planet fails because that averaging implicitly includes planetary rotation. This factor then brings up the issue of the rate of planetary rotation and the impact this rate has on mobile fluid motions (both atmosphere and hydrosphere) with the formation of rotationally induced cells of planetary circulation. Forced air circulation, whether it is separated by location with an ascending limb and a descending limb linked by advection at the TOA and a return flow at the surface or even if the circulation processes occur at the same location, then because the two motions (ascent and descent) must be time and/or space separated, a 2D model is an absolute requirement for this type of modelling study.
Atmospheric circulation modelling studies by planetary scientists have shown that the rate of planetary rotation governs the latitudinal reach of the Hadley cell. On slowly rotating planets, such as Venus, which has no equatorial bulge, the Hadley cell reaches to both poles. However on fast rotating planets, such as Earth, the Hadley cell is constrained to descend in the mid-latitudes. On Earth it is the convection from the cold cored cyclones in the temperate latitude Ferrel cell that lifts air back to the tropopause and feeds the descending air in the polar vortex of the Earth’s Polar cell.
The process of Earth’s rapid planetary rotation in governing the latitudinal reach of the Hadley cell is a component in the explanation for the geological process of planetary warmth in the Cretaceous period compared with the process of planetary cooling during the Tertiary leading to the ice ages of the modern Quaternary period. Plate tectonics allows us to understand how continental surfaces can be transported across climatic zones throughout geologic time and how mid-latitude oceans such as the Tethys Ocean, were first created and then subsequently destroyed.
In the Cretaceous the Tethys, a mid-latitude “zonal” ocean and its surrounding shallow seas, all located under the descending limb of the Hadley cell, acted as a solar energy collector and maintained a deep ocean temperature of at least 16C (c.f. the modern Red Sea). The break-up of the former southern continent of Gondwana led to the destruction of the Tethys Ocean at the end of the Mesozoic as the continental island of India moved north and created the Himalayas with the consequent replacement of the mid-latitude Tethys by the modern high-latitude Southern Ocean.
The final separation of Australia from Antarctica in the Late Oligocene completed the formation of the modern world’s island continents and also completed the formation of the Southern Ocean and accounts for the progressive cooling of the world’s ocean throughout the Cenozoic era. The Southern Ocean surrounds the island continent of Antarctica and lies beneath the meteorological zone of the Roaring Forties which is part of the southern hemisphere Ferrel cell. This modern temperate latitude “zonal” ocean is a cold water ocean that feeds and maintains the ice continent of Antarctica in a linked process of planetary meteorology and plate tectonics that has created and maintains our modern cold ice age world.
Thank you, Greg and Philip Mulholland.
It’s occasionally finding nuggets like these that makes wading through the other stuff worth it.
Thanks Joe. I have been banging on about this for some time now.
The key papers that show that the latitudinal reach of the Hadley cell is determined by planetary rotation rate (and not by the canonical process of TOA radiation cooling to space that I was taught in the 1970s) are as follows:-
Hunt, B.G. 1979 The Influence of the Earth’s Rotation Rate on the General Circulation of the Atmosphere
Del Genio, A.D. & R. J. Suozzo 1987 A Comparative Study of Rapidly and Slowly Rotating Dynamical Regimes in a Terrestrial General Circulation Model
The other feature of the story is the realisation that deep warm temperature high salinity (and therefore high density) bottom water exits the Persian Gulf into the modern Indian Ocean. Although the rate of flow is low (because the Persian Gulf is small) this bottom water is denser than the coldest bottom water produced by the Weddell Sea. The warm dense saline bottom water of the Persian Gulf is produced by the modern world’s tropical meteorological environment acting despite the existence of a low carbon dioxide content atmosphere.
The current comment posting system is not easily workable.
I truly hope it can be improved and soon.
The previous system, with navigation and rating, as well as the comment window high, was the best.
I agree .
Click in the box where it says “E-MAIL” ….. and if your name “appears” …. then “click it”.
Only thermophiles at Yellowstone National Park and other sites will need to worry about the runaway greenhouse effect.
This looks like more model porn. The program kicks out the assumptions of the modelers
Yes. There’s little difference between this and all the other models we’ve seen. But it’s nice to see one that’s hot, like an unexpected photo of Elle Macpherson among mug shots of meth addicts.
“When they plotted their data….”
Yes, and yet again these “scientists” refer to the output of their models as “data”.
Also, I seem to recall that, in a paper by Lindzen, the data does indeed show an increase of outgoing IR radiation. Problem is, this completely contradicts the climate models. According to them and AGW theory, the radiation should have been *falling* due to the effect of increased CO2. Yet another AGW prediction that is completely wrong….
Chris
Yes – more model porn.
When the models actually reflect what we KNOW* is happening in the ocean/atmosphere system, then I will examine the outputs with interest.
Increasing atmospheric CO2 is clearly a minor bit player in this huge equation, if it is significant or relevant at all. It is clearly NOT the control knob of global temperature – that claim is false.
Have these modeleers actually hindcast their models to verify if the actually work? Over what period? How many adjustments to the historic data were required to make a fit, if one exists?
Notes:
The correct mechanism is described as follows (approx.):
Equatorial Pacific Sea Surface Temperature up –> Equatorial Atmospheric Water Vapor up 3 months later –> Equatorial Temperature up -> Global Temperature up one month later -> Global Atmospheric dCO2/dt up (contemporaneous with Global Temperature) -> Atmospheric CO2 trends up 9 months later
What drives Equatorial Pacific Sea Surface Temperature? In sub-decadal timeframes, El Nino and La Nina (ENSO); longer term, probably the Integral of Solar Activity.
The base CO2 increase of ~2ppm/year could have many causes, including fossil fuel combustion, deforestation, etc, but it has a minor or insignificant impact on global temperatures.
Increasing atmospheric CO2 may cause some minor global warming and will certainly cause greatly increased plant and crop yields, both of which are highly beneficial to humanity and the environment.
https://www.facebook.com/photo.php?fbid=1556510707759819&set=pob.100002027142240&type=3&theater
“As both heat up, say by the addition of carbon dioxide, the air holds more water vapor, which in turn acts to trap more heat in the atmosphere. This strengthening of Earth’s greenhouse effect is known as water vapor feedback. ”
as long as you assume CO2 is the kick starter…..
And as Willis says, this water vapor makes clouds which shade the earth and provide a negative feedback
Not only that, but the atmosphere would expand as it gets hotter, which would increase the total outgoing radiation from the larger surface area.
The atmosphere is ~60 miles thick compared with a 8000mile diameter the increase in surface area is negligible.
Not so sure.
A 10-mile increase (from 60 to 70 miles) in the atmosphere’s thickness is about 0.5% change in surface area.
Hypothetically, as earth’s average temp increased to 152, the atmosphere would increase (unknown how much – I picked 10-miles out of a hat).
I’d like to see a little more discussion before calling a 0.5% increase “negligible”
Javert the whole cycle/heat flow from hot to cold would speed up wouldn’t it.
Expansion isn’t only at the top, the extra moisture will end up at the 2 most cold arid places the poles in solid form.
It all balances, and rebalances,………
An eternal struggle to balance is what our environment is always in 24/7, due to eternally changing forces 24/7,….
Eternal choas, ruled over by our star.
.5% increase in radiative area is not insignificant
Paul,
But clouds are only part of the water vapor, and they lose their water to precipitation. This is why wet regions are projected to get wetter, as I understand it.
Is it possible for anyone to understand it? No, it is not and if someone tells you they do, they are not being truthful.
Clouds are not water vapor.
They are liquid or ice.
Not dealing with that fact is a huge hole in the article/study.
Water vapor does contain extra (phase change) energy without necessarily being at a higher temperature. As it loses that energy, by either conduction, convection, or, ultimately, radiation, it condenses into water particles to form clouds as you say, with high albedo to reflect solar energy. It is generally thought that increased water vapor increases the likelihood of cloud formation; overall a negative feedback effect. I wonder if the “model” created in the study appropriately handled this factor. They mention only that “water vapor absorbs more outgoing radiation” which does increase its temperature, but also increases its radiative energy loss rate much more than its temperature rise (by the forth power of the change). I also wonder if their “model” handled this factor appropriately.
And it can’t happen on Earth unless you increase the amount of air equivalent to what Venus has. Venus temperature can be completely explained by how much atmosphere it has and how close it is to the sun. At 1000mb, the equivalent to 900’MSL on Earth, Venus is only 25degC warmer than Earth, what you would expect from it’s proximity to the Sun. The surface pressure on Venus is 93,000mb (pressure on Earth at MSL is 1012.25mb) If the surface pressure on the Earth were the same as on Venus our surface temperature would be in excess of 800F just due to the dry adiabatic lapse rate alone (Venus is closer to 900F)
The ocean is ~50 the mass of the atmosphere or about 100 times more molecules if all that evaporates the pressure would be about that of Venus.
Good thing that can’t happen for several billion years.
But that evaporation would result in cooling at the surface and increased precipitation in the atmosphere, would it not?
Yes it would. The water vapor is transported to the colder regions aloft and nearer to the poles, resulting in increased precipitation, which cools the atmosphere by released latent heat at altitude, and by cooling precipitation falling through the atmospheric column.
The hundreds of millions of years of stability of the Earth in a range suitable for life attests to the impossibility of the scenario that they speculate upon.
This zone of stable habitability was made larger and more habitable when the Earth was warmer and more humid. It was not a furnace at the equator when the poles where temperate to semi-tropical…it was more of less the same.
Just look at what we see in the places where we have the greatest influx of solar energy coupled with high humidity: It is not as extreme. We do not have hotter conditions, in fact it never gets as hot as in places with low humidity with even lower influx of solar energy. Temperature is in a tight and very habitable range, 24/7/365.
Note that after huge cataclysms of asteroid strikes and massive igneous extrusions, the Earth quickly returned to the stability which had previously existed.
Menicholas,
If the Earth’s climate is so stable, how do you account for periods of mass extinctions? Don’t you think it would change things a bit if the Earth were 25C warmer than it is today, as it was during the Eocene?
“Note that after huge cataclysms of asteroid strikes and massive igneous extrusions, the Earth quickly returned to the stability which had previously existed.” “Stability” and “quickly” are relative.
It’s not just temperature, but humidity, precipitation and variability that determine whether regions are habitable without loss of life. A few degrees, (from maximum of 103 F to maximum of 108 F, for instance), combined with high humidity can lead to enormous stress on the body, especially when doing manual labor. Then there are crops to consider, and the huge expense of energy to keep buildings air conditioned. And the effects on non-human organisms.
Humans very adaptable, but it can come at a cost. Other life forms are adaptable to varying degrees. Some species are pests, and already some of them have become more abundant and widespread due to AGW.
There are many factors to take into account when thinking about the effects of global warming.
“This zone of stable habitability was made larger and more habitable when the Earth was warmer and more humid. It was not a furnace at the equator when the poles where temperate to semi-tropical…it was more of less the same.”
This isn’t a direct comparison, since the position of the continents was different, creating very different weather patterns, and the sun was not as strong. (I’d like to see evidence this was the case, anyway)
Kristi, if the world warms up even to 300K which is at least 12 degrees hotter than now, then we would get to the point of a non linear increase after that according to the study. The world wouldnt get to CAGW until 340K according to the authors. However I will give you the benefit of the doubt, Kristi. I will agree that if we get to 300K then because the process wont be linear anymore, I will agree that that level would be a slow runaway warming until 340K which of course no one wants. So that means the world average temperature has to increase from its present level of 15C to 27C. That is an increase of 12C. Not even in the wildest dreams of armageddon scenarios do the computer models ever project an increase of 12 C. Dont forget that at even 12 degrees increase ; most of Greenland and Antarctica will not melt.
So unless you are willing to say that this study is junk I ask you Kristi. WHAT IN THE HELL ARE YOU WORRIED ABOUT?
27C temperature above sea level is exactly threshold temperature found also by Willis, where self regulation of atmosphere starts. Willis is observing creation of storms in Earth equatorial area, where cooling mechanism is most visible. This cooling mechanism is transporting heat and latent heat to higher latitudes where it is warming environment.
This is one really big heat pipe in work on Earth.
So basically with increasing energy balance of Earth, maximum temperature is not going
up, just equatorial belt of 27C is widening.
Tipping point is when 27C temperature reaches poles. In this moment we are losing possibility to regulate temperature and it is going up with incoming energy.
“If the Earth’s climate is so stable, how do you account for periods of mass extinctions?”
Mass extinctions are not definitely due to climate change. The K/Pg one definitely wasn’t. The end-Ordovician one coincided with a glaciation and the P/Tr and Tr/J ones with massive LIP eruptions, but the actual causal mechanisms are quite obscure. The Frasnian/Famennian event is pretty much a mystery.
The only “short sharp” temperature rise we have definite information about (the PETM) is notable because it wasn’t connected with a mass extinction, but rather with a quite remarkable diversification event.
The nearest thing to a Cenozoic mass extinction, the “Grande Coupure” at the end of the Eocene on the other hand does coincide with the shift from a hothouse to an icehouse climate.
Kristi Silber said:
“Some species are pests, and already some of them have become more abundant and widespread due to AGW.”
You say this as though it is fact. Please provide links to conclusive scientific proof that AGW has caused more abundant species, pest or otherwise. Oh…wait…I guess polar bears could be considered pests I susppose, and their numbers are increasing.
PBWeather her false premise was AGW.
She could not prove it a reality if her life depended on doing so.
The whole quote is pure sophistry.
The least habitable places, lowest-biomass areas on Earth are also the coldest.
This is not a coincidence.
It is also most unlikely that even if Earth heated appreciably, its atmosphere would become like that on Venus. Earth has a strong magnetic field; Venus does not. The lack of such a field on Venus means gases in the upper atmosphere have no protection against energetic charged particles from the Sun. These dissociate water molecules into hydrogen and oxygen, and the hydrogen is lost from Venus. The oxygen reacts with surface rocks. A similar process occurs on Mars. It does not on Earth.
That’s one of those chicken/egg conundrums. Venus’ atmosphere is so thick it may have actually killed off the magnetic field by dragging the planet’s rotation nearly to a halt.
One new WAPpish theory that I like is that a giant primordial Moon-forming impact on Earth imparted enough momentum to keep the dynamo going and preserve the hydrogen. This could also go a long way towards explaining why all these Goldilocks exoplanets are not teeming with radio signals from alien civilizations.
https://phys.org/news/2017-12-doesnt-venus-magnetosphere.html
There’s no way that an atmosphere can slow a planets rotation.
https://www.scimex.org/newsfeed/thick-venus-atmosphere-slows-planets-rotation
Assuming it happened, the collision with the exo-planet could have increased the rate of the earth’s rotation. However the presence of the moon that formed from collision converted most of that extra energy into extra orbital velocity for itself.
That collision made the earth’s magnetic field stronger because the result of the collision was that the earth contained the core of two planetoids, while dumping most of the crustal material into space.
https://newatlas.com/venus-rotation-slows/21453/
According to Wikipedia, the methane concentration of Uranus’s atmosphere is around 23,000 ppm.Two things to note: (a) methane is regarded as an uber-greenhouse gas and (b) Uranus is really, really cold.
Methane isn’t really an “uber-greenhouse gas”, that is CAGW phantasy. And Uranus is to cold to have appreciable quantities of the only real uber-greenhouse gas, water vapor:
And that water vapor absorbs the energy and never, ever, re-radiates it.
A desert at night is warmer with clouds than without clouds.
“A desert at night is warmer with clouds than without clouds.” That may be true but, being a desert, there are not many cloudy days or night and there are still warm and cold fronts regardless of clouds moving through the region.
Correct. Absorbed IR-radiation in the lower troposphere is very largely thermalized.
And my take is, ……..
That “magical” water vapor feedback is only about 15% effective when you’re talking “humidity” only, ……. and in actuality it is 0.0% effective when you’re talking about the tens-of-millions of square miles of the earth’s surface that is desert environment.
And that “magical” water vapor feedback is highly questionable when you’re talking only “water droplets” in the form of clouds, fogs, mists rain, snow and/or sleet.
Could it be that the Globe is more than a black body radiator that receives/radiates energy based upon its albedo at the surface? The atmosphere contains trillions and trillions of radiators helping to transfer that energy. Could it be that these atoms/molecules in the atmosphere radiate energy in 360 degrees? And since it is 360 degrees that means half of it goes into space.
More than half, with altitude
Not being an expert and having little data on this topic, I notice they left something out of their calculations. They say that more water vapor absorbs more escaping infrared, cancelling out the increase in infrared leaving the planet. But I’m aware of other studies that determined that increased water vapor due to warmer temperatures resulted in increased cloud cover and thus increased albedo. I think they’re ignoring inconvenient data.
Art,
There is also evaporative cooling. Maybe they took the non-radiative effects of H2O into account. Or they might simply have ignored or parameterized them, like IPCC’s GIGO modeling kludge.
They must have parameterized them. Current GCM:s are utterly unable to handle convection numerically. It would very conservatively need computers 100,000,000 times more powerful than available today.
My interpretation from the article was that their model was 1 column, surface to space, not ALL columns.
This could include convection, but would miss advection.
Clouds can also hold in heat at night.
More importantly, we don’t know what they accounted for or discussed in the paper, since this is just a press release. You don’t know what they are ignoring; why make assumptions?
Clouds work both ways depending on the circumstances, cloud types and lots more, that is true. However, the net effect of clouds on the climate overall is believed by some (incl. NASA) to be a general cooling effect around 5°C.
“Clouds can also hold in heat at night”
Indeed. But convective clouds build up during the day and disperse at night. Have a look at what happens every day along the ITCZ here:
https://www.smhi.se/vadret/nederbord-molnighet/satellit-jorden
Most places that are cloudy most of the time also tend to be cool
“The team found this linear relationship breaks down when Earth’s global average surface temperatures go much beyond 300 K, or 80 F.” is this 300K based upon the average of the entire globe??? Why. Seems to me that major portions of the earth will always be well below that number and thus still be able to get rid of heat. Then there is the night/day problem where the dark side will be cool enough to still work effectively.
This is an illustration of why average surface temperature is completely meaningless.
Thank you. Thank you. Thank you!
For the most part, “average” anything temperature is meaningless, else we could not grab the handle of a pot of boiling water.
http://www.pnas.org/cgi/doi/10.1073/pnas.1809868115
Kirshna,
I tried that, but it says “DOI Not Found”.
Did that work for you, or did you post it without verifying it?
I came up with the same URL from a different source, but my comment is AWOL at the moment. I’m wondering if the report was taken down.
The DOI hasn’t been activated yet, will happen when that edition is published.
Tried that URL, found a PNAS page saying I was not authorised to view the paper, first become a member by sending money. Geoff.
DOI Not Found
10.1073/pnas.1809868115
This DOI cannot be found in the DOI System. Possible reasons are:
The DOI is incorrect in your source. Search for the item by name, title, or other metadata using a search engine.
The DOI was copied incorrectly. Check to see that the string includes all the characters before and after the slash and no sentence punctuation marks.
The DOI has not been activated yet. Please try again later, and report the problem if the error continues.
Probably withdrawn because of the negative effect it would have on the primary source of funding for most of the 629 Public 4-year and 1,845 Private 4-year U.S. colleges and universities. If not either withdrawn or falsified it would be the death knell of CAGW (i.e., Catastrophic Anthropogenic Global Warming).
Source of the DOI:
https://phys.org/news/2018-09-earth-space.html
Looking at co-author Tim Cronin’s recent CV on the MIT website, this paper is listed as accepted by PNAS:
http://web.mit.edu/~twcronin/www/document/Timothy_Cronin_CV_2018-08.pdf
Similarly, http://geosci.uchicago.edu/~dkoll/publications.html says
Er . . . the proto earth was molten and all that carbon in limestone, marble, coal, petroleum, etc. was once in CO2 in the atmosphere. Shame on MIT.
Shame on MIT…. PNAS Heads.
Shame on MIT…. bunch of PNAS Heads.
At 156F, the peak emission will be about 8.5 microns, while at 56F it is about 10 microns. It seems like we begin moving the peak right out of the absorption spectrum for CO2 (15, 4.3, 2.7 microns ), which means we go back to a T^4 relationship in energy output.
looking at temperature emissions, 15 microns is about -112F or -80C. Does it ever get that cold? (yes I am aware that the energy is spread into longer wavelengths and it is this tail which get absorbed. however, the hotter it gets, the less energy is in those tails in the 14.5 – 15.5 micron band and at 156F even water is in a low absorption mode over the bulk of the emitted energy -[falls off at about 10 microns.]) It looks to me like CO2 and even water are more effective at blocking high altitude atmospheric emissions than the direct from the equator to temperate surface emissions.
15 microns has nothing to do with a temperature of -80ºC, the hotter the temperature the more IR gets emitted at 15 microns. At -80ºC a BB emits 2.2 W/m^2/sr (14-16 micron) whereas at 156ºF it emits 20.3 W/m^2/sr, i.e. about ten times more.
True, but that won’t sustain the higher temperature as the escaping W/m^2 at the unaffected wavelengths are even higher. What sustains the system at 150+ F when the majority of the radiation escapes to space, cooling the surface? Even if that entire 20.3 W/m^2 were to reradiate downward, adding it to the energy of the sun might get us to 100F for a stable temperature. I don’t see this working even on a radiative physics basis. There is just no way to sustain the elevated temps without the sun’s output changing or our orbit decaying to closer to Venus’ distance.
And 15 microns is the wavelength of greatest intensity at the Earth’s effective temp of 255K (temp at which Earth radiates it’s Solar absorbed SW via LWIR).
And the Earth’s temp as seen from space at it’s effective radiating level (-18C at ~8km in the troposphere).
Which is why CO2 is important as it is not entirely absorbed by WV.
“a lump of physics smashed together” – a climate collider? in the code?
Well, we’ve seen many past climate predictions\projections collide with reality and lose badly.
Yet they keep making new predictions\projections without fixing what led to the past failed predictions\projections.
worse than that….they keep building on those failed predictions like they never failed
Actually, “climate science” is an awful lot like psychology in that respect (or lack of respect).
Hey , my degrees are in psychology .
Sorry , you’re right .
“The code simulates the Earth as a vertical column, starting from the ground, up through the atmosphere, and finally into space.”
Simulating the Earth’s atmosphere as a column seems like a pretty unrealistic way to simulate the Earth’s atmosphere. It would be interesting to know the diameter of the column they use in the simulation as well as how (or if) they simulate the interactions between the atmosphere outside the column and the atmosphere within the column.
I noticed that too. Sounds like they completely ignored advection. Nearly all the all-time record lows for various states in the lower 48 occurred when an arctic air mass advected from Siberia. (got to get that Russia is at fault Meme in there somehow 😉 )
“Nearly all the all-time record lows for various states in the lower 48 occurred when an arctic air mass advected from Siberia.”
In Northern Ohio, we blame Canada for those cold “Alberta Clippers” that pass through here in the winter. 🙂
Northern Canada is generally colder than Siberia with the land of the archipelago.
Generally yes. But back before computer plotting of weather charts (I know that was in the stone age), I noticed as I was dutifully plotting, that more than once that the *really* cold weather started first in Siberia.
LOL. And Canada blames Alaska, and Alaska blames Siberia.
Its all upwind from here…..
I think it is good way simulate it by column. We can ignore lateral movement, because it is only borrowing/lending energy between columns. Total energy content is same.
Imagine this column like one pixel on screen. They changed inputs and checked total output of pixel. They simulated physics in column, changed temperature, content of vapors etc. and measured single output information.
They found this linear dependency of output energy based on temperature.
If this works for one column with all physics included, it will work for all columns e.g. whole atmosphere.
This is no mere model porn, it’s tuned to fit NY politicos style of “ban it out of the abundance of caution” policy tactic. Attorney Generals armed with Surgeon General reports would rule in this pre apocalyptic scenario.
There’s a very poor copy of the MIT story at http://www.todaychan.com/how-earth-sheds-heat-into-space/ that concludes with:
Expertise? How about this paragraph?
The URL https://www.pnas.org/cgi/doi/10.1073/pnas.1809868115 fails. At first I thought there was a typo, but now I’m suspicious that the paper has been taken down. That would explain why it’s not findable at PNAS, not listed in their recent papers, etc.
No it won’t work until the edition is published.
There does seem to be one tipping point. The planet currently bangs into and out of interglacials. There are lots of theories. If that is so much in doubt, how is it that CAGW theory is so certain?
Right !
The only tipping point around is 273.15 — and that is smeared over latitude and salinity .
If the climate really is a “… coupled non-linear chaotic system…” as IPCC says and the climate follows a Strange Attractor as many chaotic systems do, then there really are no tipping points as two adjacent points on the Attractor can lead to very different outcomes for the climate.
There cannot be just one tipping point…If there was only one, it would be a point of no return, a one way street.
152 F. .. so how would that work?
What would the temps be in various regions of the world to average out to 152 F.? Would this even be possible for planet Earth?
And the Venus reference, … I dunno — I’m feeling a Venus debate coming on.
I couldn’t find the paper anywhere either, not even an abstract.
Not much to comment on without that.
Evaporation in the equatorial zone caps tropical sea temps at 31C. Watervapor, is lighter than air and being heated as well, it rises quickly raising the mass of warm air as in a chimney and bypassing much of the radiation absorption activity close to the surface, it emits the heat from a higher altitude more quickly into space. Perhaps not very well phrased (a bit tired!).
This column model would appear to be too ordered a set up for the dynamics of the atmosphere. Talking about ideal ceteris parabus emission equations in a roiling air mass. That’s just it you can’t study ‘parts’ of such a system. After hearing about radiative physics of CO2 and water vapour in the laboratory fot the 1000th time, told as if to an idiot child, I argued that they excluded all the confounding agencies that in the real system act to counter the effect. I did a thought experiment. Set up a heated globe in the lab and measure temperature at a various distances outwards in a line colinear with the centre of the globe. Wonder of wonders you discover the square of the distance relationship of temperature from the surface. Now, in the real world the difference in the distance of the earth from the sun in its orbit (aphelion to perihelion positions) is a significant ~ 4%. Now see if you can identify this regular variation in the global temperature trace. There isn’t one. So, now what do you say to your idiot sceptical child.
That the ‘idiot skeptical child’ should read up on Kepler’s Law of Areas.
Gary,
Local and regional SSTs can and do exceed 31 C. For example, the Red Sea in July.
But for large open ocean areas, you might well be right. And even for most of the Persian Gulf, most of the time.
I personally have seen SST observations @95Deg F, back in the day before computer plotting of obs, I had 2 reports from ships in the Sea of Cortez (Gulf of California) with SST at 95. This was in the middle of the summer and was more than like seawater injection, not true SST so the actual SST was more than likely 90F. Still quite hot, and yes it was a confined, relatively shallow body of water. As several others have posted here the oceans are a humongous thermal damper, it would take Armageddon to raise Earth’s temperature much higher than has been seen in geologic history (85F) considering how much COLD water is in the oceans.
Venus is not the case of runaway GHG’s, but the case of 100% cloud coverage where the clouds are an independent thermodynamic system from the solid surface below. In the case of 100% cloud coverage on Earth, the clouds are still connected to the surface by the hydro cycle. It’s not until liquid water can’t exist on the surface that Earth has a chance to be like Venus and that’s closer to 212F. Instead of 90 bars of CO2, there would be 90+ bars of water vapor and whose temperature profile from the clouds in equilibrium with the Sun down to the solid surface below will follow that of a gas under compression which is independent of GHG effects.
Atmospheric pressure of almost 100 times that on earth probably has a lot to do with venus’s temperature along with being 25% closer to the sun.
And that atmospheric pressure is due to and calculable from gravity , the other macroscopic force .
It’s important to distinguish gravity acting on a gas as setting what the temperature profile must be and is not the source of any heat itself. Differential gravity, for example, the tidal heating of Io, is not a source of heat either, as the source of the energy heating it originates from orbital and axial rotational energy. The only time gravity is converted into energy is as the gravity of mass disappears when converted into energy.
No .
The tradeoff of gravitational and kinetic ( heat ) energy is universal , does not require convection , and very simple to understand .
A particle moving up in a gravitational field slows down , ie: cools ; one moving down speeds up , ie: heats . Doesn’t matter if it’s in a crystal lattice or a fluid . And everything else can be worked out quantitatively from Newton’s gravitational law .
Does that need any further explanation ? A particle above receives less energy from one below and visa versa .
Only including gravitational energy , which it is easy to show computes as a negative , can the total energy equations be balanced .
Convection occurs when that natural gravitational “lapse rate” is “upset” by , eg: thermalization of radiant energy at the surface .
You’re missing the point. The comment was about the nature of the heat in the Venusian atmosphere and it’s not gravity. The source of all the energy stored by Venus in its clouds, CO2 atmosphere and solid surface is the Sun where temperatures are a manifestation of stored energy and a temperature profile is a manifestation of an energy storage profile which in the case of Venus is a function of gravity.
Temperature is not a property of the velocity of an individual molecule, but is a bulk property manifested by many molecules moving in all directions over a range of velocities, thus any net energy gain/loss of the kind you’re referring will be zero.
Sorry , again .
There are other groups now , like Destroying the AGW Hypothesis where the gravitational thermal energy trade off is being better understood .
I’m just interested in the computational physics , the fundamental quantitative relationships .
If you leave gravitational energy out of the equations , you are denying conservation of energy and thus also basic thermodynamics which says that thermal energy will flow from higher density to lower .
The Calculation of Equilibrium Temperature of a Colored Ball determines the radiative equilibrium temperature of a ball of arbitrary spectra irradiatied by arbitrary source and sink power spectra . For a planet & atmosphere . eg: the earth , that effective radiative surface is wavelength dependent and varies from the surface in the visible to somewhere in the upper atmosphere for most of the IR . ( Hansen’s 1981 claim , https://pubs.giss.nasa.gov/abs/ha04600x.html , is that more CO2 moves it’s effective radiative surface up to where it’s colder ( why ? ) so it radiates less trapping more heat below . Nonsensically circular ( & w/o equation ) . )
As pointed out in my http://climateconferences.heartland.org/robert-armstrong-iccc9-panel-18/ , the 2nd year calc Divergence Theorem is one way to state the thermodynamic fact that the interior of a ball must have the same average energy as that surface . The thermal energy density at the bottom of Venus’s atmosphere is ~ 25 times that which the Sun provides to its orbit .
The spectral GHG hypothesis , for which I have yet to see the few simple equations which would justify it despite it being my constant question , violates this . Were it true , we could immediately replicate the phenomenon and quickly make perpetual heat engines . So , once again , show us the basic enabling equations . Nothing to do with planets or atmospheres or clouds , just the basic physical law .
The gravitational people have . And it quantitatively explains adiabatic pressure temperature profiles for all planets looked at . And as I pointed out , it is very easy to understand and work out the equations for . And it is ubiquitous applying not just to atmospheres but continuing into the bodies of planets .
My central interest is developing 4th.CoSy as a language for implementing this sort of physics . So the essential question is what is the differential to go in a voxel because then it can rather easily be mapped over a sphere . The spectral equilibrium calculation cited above is part of it . I believe the Schwarzschild thermal differential is the complete spectral thermal differential excepting gravity . Get a handle on these equations for the static case , eg: a cat’s eye marble , then “melt” its surface and solve the dynamic case .
But the spectral GHG paradigm from my perspective and a rapidly growing number of others is patently defective . If not , show us the fundamental testable enabling equations and explain how gravitational energy , which so conveniently computes as a negative , can be left out of the accounting .
Bob,
Gravity is not a source of energy. It’s a consequence of how matter shapes space-time. Gravity certainly comes in when calculating the lapse rate, but this is a rate, not an absolute and the absolute is dictated by the energy originating from the Sun.
The spectral evidence for GHG absorption is clear and predicted by Quantum Mechanics.
The spectrum I predict based on absorption per HITRAN line data is the same as we observe and that the only way reduced energy in parts of the spectrum can appear is if their energy is absorbed by the atmosphere. The atmosphere is not an infinite repository of energy and in the steady state, energy leaves the atmosphere at the same rate its being absorbed, except it leaves over twice the area that it arrived.
I find it astounding that anybody with even a high school physics background could say “Gravity is not a source of energy.” It’s like you somehow think general relativity negated Newton rather than put his laws in a broader context . Perhaps see https://en.wikipedia.org/wiki/Gravitational_energy .
I could go on , but the claim that distance times gravitation force , the other macroscopic force , is not energy , is nonsensical . It is virtually the canonical most classical example of the relationship of force and energy .
Again , please show the essential equation which enables the asymmetric trapping of heat by a spectral phenomenon . Something I can program in a voxel in a planetary model .
Yeah, and I noticed something weird when I googled Venus lapse rates. Neither Venus’ lapse rate, nor Mars’ lapse rate had evidence of convection, i.e. no troposphere & tropopause.
The tropopause is due to the fact that the Earth’s atmosphere has a second heat source through the absorption of UV by ozone in the stratosphere. The tropopause is simply the point where the upward movement (mostly convection) of heat from the surface and the downward movement (mostly radiation) of heat from the stratosphere balance.
“Koll says the team’s results may help to improve climate model predictions.”
Koll obviously misspoke here as we all know that climate models don’t make predictions they make projections.
Regardless, how can you improve something that’s already perfect?
Good Point! 🙂
More BS. The Cloverly Formation does however contain crocodilian critters. Something I did not know. Interesting though of course quite biased by their modeling assumptions. Comments like, if the earth heats up due to co2, gets them their grant.
How many doublings of atmospheric CO2 to get there?
A few trillion more coal trains of death, eh Jim ??
Coal trains of death? Coal trains of prosperity for people, industry and plant life is more like it.
Different Jim, Jim. Google coal trains of death, boiling oceans and the like.
Different Jim, Jim.
Google coal trains of death, boiling oceans and the like.
Not you, he meant that for James Hansen. (And should’ve said James.)
https://wattsupwiththat.com/2012/07/17/hansens-death-trains-now-with-extra-scary-coal-fallout/
What is a “radiation code?” It obviously means a computer model, but why this strange term?
In my many years of writing computer programs, I never ran into “radiation code” but I have seen “radioactive code” which was code that was so badly written and so poorly documented that computer programmers always made sure they were busy doing something else when the “radioactive code” needed to be modified or rewritten.
HPTC (High Performance Technical Computing) folks tend to call their big programs “codes”. It’s a term I’ve never liked. OTOH, old codes written back in Fortran IV days before Fortran picked up vector/array math notation and several other modern concepts are often referred to as “dusty decks” for the thousands of cards that make up what are today’s ancient scrolls.
It is a fairly common term. Google “MODTRAN” for more information. By the way what they describe as new revolutionary science seems to be very much a pure copy of MODTRAN.
And note that MODTRAN was developed by the need of the military for accurate data on IR transmission in the atmosphere, so it has been thoroughly validated.
From their description it sounds more like HITRAN.
I’m sure the media take away will focus on the “runaway” and “Venus” portions and ignore the impossibility of the whole situation.
Visualising the Earth’s atmosphere as a column seems like a fairly close ‘scientific’ companion to the looney Flat Earth Scenario.
I suspect the authors had ‘modeled’ a column of atmosphere above the surface area in question. While not exactly geometrically accurate (should be a spherical sector) I’ll further suppose they simplified it to reduce coding, or perhaps they accurately modeled it.
What they didn’t take into account has been mentioned in above comments, that of mixing between columns and energy spent to create wind and clouds.
Without anyone being actually able to read the paper this is all speculation.
Its all very interesting, but surly a good look at Earths past climate history would be a far more accuraate way to say how things actually work.
MJE
It would tell us what happened, but not why. We will still need to generate a theory which will account for the observations.
Isn’t that what we are doing?