The IR absorptive characteristics of “greenhouse” gases–David Coe
By Paul Homewood
Physicist David Coe has sent me a paper he has written on the IR absorptive characteristics of “greenhouse” gases, which I am delighted to publish.
CO2 The Miracle Molecule
SUMMARY
Using well documented data on the infra-red absorption spectra of atmospheric gases it is a straight-forward process to infer the overall atmospheric IR absorption and from that the effective global average temperature. The simplest of atmospheric models has been used: the atmosphere is considered to be a uniform thin absorbing layer of gas. The results demonstrate clearly that the warming effect of the atmosphere is almost entirely due to the spectral absorption characteristics of CO2 and H2O. They are both exceptionally strong absorbers of infra-red radiation. It is however this strength which determines the characteristics of the earth’s temperature, and in particular its stability.
70% of the energy radiated from the earth is removed by a mixture of 0.1% H2O and 200ppm of CO2. This alone is sufficient to raise global temperatures from the chilly 255K of the estimated zero atmosphere condition to 284.3K, less than 4deg below current average temperatures. An estimation of the current atmospheric mixture of gases is calculated to deliver a global mean temperature of 286.8K close to the best estimate of 288K for that temperature. Further increases in both H2O and CO2 have relatively small impacts on temperatures. This is due simply to the fact that at current concentrations the spectra of both H2O and CO2 have effectively extracted most of the energy at wavebands corresponding to their molecular absorption spectra. There is little further energy to be extracted by adding more H2O and CO2. This results in climate sensitivity values of less than 0.5degC, in comparison to the 1.5 to 5 degC range quoted by the IPCC.
CO2 levels of 3000ppm will only raise temperatures by a further 1.5K. These temperature increases are in fact well within natural variations seen in the past, including the medieval warm period and the little ice age of some 300 years ago.
The possibility of positive feedback from water vapour is discounted by the simple fact that the H2O spectrum is incapable of absorbing significant further amounts of radiated energy and the modest increase in temperature due to increasing CO2 levels is unable to deliver any significant increase in H2O concentration due to the specific relationship of H2O saturation vapour pressure and temperature. It would take an increase in temperature of 10degC to double the mean H2O atmospheric concentration, and that doubling would only result in a temperature increase of 2degC.
The impact of other known “greenhouse’ gases, CH4 and N2O are also calculated from known IR spectra data. Their absorption spectra are swamped by H2O and CO2. The combined warming caused by current atmospheric concentrations will elevate temperature by only 0.2K and increasing concentrations by a factor of 10 will only result in a further temperature increase of 0.5K.
The “greenhouse effect” is dominated by the absorption spectrum of H2O with a little help from CO2. At current concentrations of both gases it is inconceivable that further increases in concentrations will lead to any significant warming. Increasing CO2 concentration to 3000ppm and doubling the mean H2O level to 2% would result in a global temperature increase of 3.4K.
In short, there is no climate emergency, at least due to “greenhouse gases”.
The full paper can be read here:
co2-the-miracle-molecule-22637
More about the author:
I am a physicist, having read physics at Oxford back in the sixties. My day job for the last 20+ years has been developing a range of sensors for the monitoring of gaseous emissions to atmosphere using infra-red absorption spectroscopy. I thus have not only some knowledge in this area but have access to a database of molecular absorption spectra for most common gases, particularly CO2 and H2O. I am the founding director of the company Codel International Ltd, based in Bakewell, Derbyshire.
David Coe
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NOT A LOT OF PEOPLE KNOW THAT 
Not quite on topic but I wonder if you have seen article in yesterday’s Daily Telegraph magazine. Maybe a glimmer of hope? Is it connected with the passing of David Barclay?
But the science is settled. Burn the heretic!
“Science” that is “settled” is not science.
Exactly! Science is never settled in the absolute sense..
A very straightforward analysis and so should be very easy to refute with a similarly straightforward counter argument by any physicist or climate scientist who believes there is a climate emergency. Can we offer the challenge?
This paper is extremely positive and welcome but also novel – I am absolutely new to these ideas. Is this a realm where peer review would really help to convince not only me but the other few followers who want these ideas to be true?
Peer review is greatly overrated. For some time, peer review has been captured by those wishing to push the climate agenda. Only those papers which sing from the right page make it past the “reviewers” and into the journals.
You should look up the Climategate history from the University of East Anglia’s Climate Research Unit (CRU). This was the scandal with Michael Mann et al exposed by McIntyre and McKitrick. “Nature” refused to publish their paper which doubted some of Mann’s research claims. The CRU (I refer to them as the Motley CRU) members had many emails which espoused taking over journals, getting editors who disagreed with them removed and even bringing down journals which they deemed “unfriendly”.
You might want to look at “The Hockey Stick Illusion” by A. W. Montford and “A Disgrace to the Profession: the World’s Scientists in their own words,” by Mark Steyn. Steyn’s book is a compilation of writings and statements by leading scientists (many of whom actually did support the idea of global warming, but not what was being done in the name of “science”).
Could not agree more!
I am well aware of the abuses of peer review and have read all the references but when something as radical as this is proposed by one person what orther way is there to know whether its real or fantasy? At a stroke it can finally put paid to the “science is settled” claim.
There was a time before “peer review” when the findings were published for all to read and comment. A requirement (now basically “overlooked”) was that the data be available for other scientists to conduct their own “peer review.” It is a significant part of the now greatly ignored “Scientific Method”. Increasingly, many involved in what now passes for science refuse to release the data. So they can come out and publish with their “friendly” editors and dare anyone to disagree.
One of the CRU gems involved a data base of 250 trees cored in the Yamal Peninsula. One author cherry picked 20-25 trees for his contention that the dendrochronology showed increased CO2. Dendrochronology is basically useless for this determination as there is too much “noise” to make it even remotely reliable. Another of their scientific wizards based his study on THREE of those trees. They should have been laughed out of town for their infinitesimally small sample size which rendered anything they had to say meaningless.
For my plant ecosystems doctoral study of vegetation over diabase dikes and sills in the Gettysburg Basin of Pennsylvania, I had a total of 58 15m x 25m plots laid out over 12 sites in 3 counties. Vegetation was determined as canopy, sub-canopy, under-story, shrubs and herbaceous. I collected both soil and rock samples for each plot. The rock turned out significant as a geologist was able to tell me the grain size and position during deposition (when the US was leaving Africa in Jurassic). The vegetation patterns were subject to the water flow through the fractured or not so fractured diabase. Both northern and southern comparison areas were sampled (CT and NC). My dissertation is 300 pp and includes all data as an appendix. As you can see, this is slightly different from 25 or 3 trees and the data is readily available to all.
That would have been a sensible comment 25 years ago, when scientific journals and publishers and peer review had some integrity and were at least intended to honestly further the cause of real science.
What value does publication/peer review by/in a small-fish outlet do these days when all the ‘prestigious’ journals and institutions are only concerned with gate-keeping and affirming the climate orthodoxy. By and large alarmist reviewers will reject/dispute it regardless, and skeptics (if there are no genuine errors) will validate it.
Hence why alarmists smugly and disingenuously dismiss contrarian views with ‘show me the peer reviewed paper’ or ‘how many papers have you published’. It’s just one of the many fallacious argument tactics they use.
Read, understand, and make up your own mind, don’t fall for the appeal to false authority.
Actually, none of this is particularly ‘new,’ since it is in fact a reiteration of the largely settled science that Tyndall bequeathed to us. The only thing that Tyndall did not know was the true nature of ‘radiant heat,’ which was discovered by the end of the Nineteenth Century.
Many of the ‘usual suspects’ in the formation of CAGW hysteria published similar calculations in the early part of their careers – except that they expressed it then as “ONLY a 2 C rise.” There is not much you can say, after announcing “Nothing going on here!” and so – to avoid end-of-career blues – the message was tweaked to “a BIG 2 C rise;” while about the same time Margaret Thatcher made the catastrophic mistake of introducing it to an international audience of world leaders with the message, “I am a trained scientist – so listen up to this bad news!” Which they did!
Twisters and trouble-makers of every kind realized they could ‘weaponize’ this idiocy. The sheeple invested their emotions. A new brand called “Climate Change” was created to keep the interest up.
The rest is history.
I have been ‘banging on’ about this for perhaps 20 yrs. Read id in a book about common myths from a senior scientist at Cornell.No green friend has ever replied to my argument
About the “chilly 255K of the no atmosphere condition”.
https://tambonthongchai.com/2020/12/19/the-greenhouse-effect/
The faint young sun paradox
https://tambonthongchai.com/2020/12/21/the-faint-young-sun-paradox-geological-co2/
How can this information be communicated to the government and population at large? The media are censoring out this information. Teachers at schools are indoctrinating the children to the extent climate doom is affecting them mentally. Increased CO2 has more beneficial effects and little downside. I really despair that the truth will be submerged by political and industrial corruption. Need to drag those publishing false hoods into court where lies can be exposed. A class action. Who will take up th challenge. There is a class action in progress against the WHO and a number of German “experts” in USA.
Right on Charlie.
Paul do we get messages like this out to the wider population and encourage debate to debunk the rubbish we read in the papers and on the BBC?
Is David Coe going to answer questions?
If I possibly can.
This informed , cogent and sadly these days it has to be said , brave piece is just what we need to help prove that we are right and they are wrong .
Unfortunately public policy is made by clownish , face – saving politicians who inhabit rainbow – unicorn world , and are intent on increasing taxation and regulation .
Among public figures I can hardly see creatures like the scoundrel Attenborough making a public recantation any time soon . Who knows though ? – Perhaps the BBC are already filming ‘ Fifty climate liars of our time ‘ , now that they’re committed to representing a wider range of opinions . Ho ho ho .
David, thanks for the very quick response.
I wanted to ask you about Nitrogen and Oxygen which are obviously at the same temperature as the CO2 and the H2O. wherever they are in the Atmosphere.
How does the atmosphere shed the heat stored in the Nitrogen and Oxygen, I am aware of their microwave energy, but is that of sufficient power to remove the heat?
Nitrogen and Oxygen have no significant infra-red absorption bands. They thus neither absorb nor emit radiation. They are totally transmissive and are simply bystanders in this process. They do of course do have thermal capacity, but they gain and lose their heat by molecular collisions and convection within the atmosphere. Water and carbon dioxide do the radiating on their behalf. Hope this helps.
Yes and therein lies a problem.
The general description of a “greenhouse” gas is one that absorbs heat to keep the earth warm, which both N and O2 do via kinetic energy.
So if there was no CO2 how would N & O2 lose their heat to space?
Does that not make CO2 a coolant?
In response to your comment below, if the atmosphere was made up of entirely oxygen and nitrogen, there would be no IR absorption and the earth temperature would still be at 255K. So would the oxygen and nitrogen. The only way that the earth can lose energy to space is by radiation.
But it isn’t only N & O2, it is as it is with water and H2O in the atmosphere which is the real radiator.
So if N & O2 can’t radiate in the upper atmosphere beyond H2O and only CO2 can, then surely CO2 must be a coolant?
Taking the kinetic energy imparted by the H2O from the N & O2 and radiating it to space.
It behaves as a coolant, in the upper atmosphere, as more photons can escape to space, than are radiated back towards the ground.
David says, “They do of course do have thermal capacity, but they gain and lose their heat by molecular collisions and convection within the atmosphere”.
So there is a residence time for convected surface heat in the atmospheric nitrogen and oxygen yes? And that said heat energy, sourced from the surface, residence time is very long and, sans a GHG, can only escape by back convection returning to the surface, and there, via radiation going to space, yes? So the surface is then receiving whatever TSI input exists, plus back convection of ? WsqM.
So would this not raise the surface T above a non gaseous planet, particularly at night, it at least particularly easier to visualize at night.
Also, the denser the atmosphere, the longer the residence time of said convective, the greater the total energy stored in the atmosphere, the greater the convective energy back convecting to the surface to finally radiate to space.
David Coe wrote
“Nitrogen and Oxygen have no significant infra-red absorption bands. They thus neither absorb nor emit radiation.”
The satellite temperature measurements are a measure of molecular radiation from oxygen or nitrogen, I don’t recall which at he moment. It isn’t IR but it is radiation. It removes energy from the earth system. Everything above absolute zero emits radiation.
Has this non-IR radiation total been calculated or measured. Why is it assumed to be insignificant?
[[The results demonstrate clearly that the warming effect of the atmosphere is almost entirely due to the spectral absorption characteristics of CO2 and H2O. They are both exceptionally strong absorbers of infra-red radiation. It is however this strength which determines the characteristics of the earth’s temperature, and in particular its stability.]]
So many people are ignorant of radiative physics based on Planck’s Radiation Law, the master law that covers all cases. CO2’s absorption/emission wavelength of 15 microns has a Planck radiation temperature of -80C, colder than dry ice, and can’t melt an ice cube. The Earth’s surface temperature range is -50C to +50C, hence atmospheric CO2 can’t absorb or reemit any ot this infrared heat, and can’t even interfere with Earth’s climate. CO2-driven global warming is a fake physics hoax based on mass ignorance of radiative physics, and sadly even most physicists fall for it.
Study my free article that patiently explains the physics needed to see that CO2 can’t raise global temperatures even 1C:
https://www.quora.com/What-specific-chemical-properties-of-carbon-dioxide-causes-the-greenhouse-effect-Why-chemically-is-carbon-more-reflective-than-other-gases/answer/TL-Winslow
Coe’s summary and conclusion is very much in line with that of John Kerr in his excellent book The Inconvenient Skeptic. But such findings will matter not a jot to the warmest blob. Their agenda goes way beyond proper scientific analysis and debate.
Unfortunately I think you are right. But we still need to try.
We certainly do.
The only atmospheric gases which trap heat are ozone and water – they both have permanent electric and magnetic dipole moments. CO2 has neither. CO2 is just ordinary radiative gas – it can only absorb an IR photon during a collision which induces a dipole moment – and only when the collision is along the longitudinal axis. And after it absorbs the IR photon, it ejects it nano seconds later. CO2 does not trap heat.
It’s the oceans which absorb the IR photons which break the hydrogen bond in between the water molecules on the surface to produce rain clouds.
Global warming is now 100% political, not scientific. It probably always has been.
I think a serious contributing reason to Donald Trump being so relentlessly targeted for 4 years, being ‘beaten’ under highly questionable circumstances and being falsely impeached (not once but twice) is his climate change scepticism.
I believe he had Will Happer lined up for a big climate announcement. ‘That’s been nixed just in time’, Big Green might have said.
Quote by Ottmar Edenhoffer, high level UN-IPCC official: “We redistribute de facto the world’s wealth by climate policy…Basically it’s a big mistake to discuss climate policy separately from the major themes of globalization…One has to free oneself from the illusion that international climate policy is environmental policy. This has almost nothing to do with environmental policy anymore.”
So why, somebody explain, are they still getting away with it? Schellnhuber is on record as admitting that the 2° “target” is meaningless and was only created to keep the pollies happy because they like simple numbers they can wrap their minds round — think ‘5-a-day’ or ‘14 units a week’. I can find another couple of hundred quotes, including Hansen’s admission that “GAT is not a useful metric”.
Joan Gibson’s comment above sums it up nicely. They’ve suborned scientific publishing to push what is in effect Lysenkoism and idiots like Johnson or Biden fall for it. They keep admitting the whole thing is fraudulent and we never listen!
If there were no greenhouse gasses in the atmosphere and it was virtually all oxygen and nitrogen which are monatomic gasses and cannot radiate then how hot would Earth be?
You can calculate this using: the Stefan-Boltzmann constant, the temperature of the sun, the radius of the sun, the sun-earth distance, and an estimate of the Earth’s albedo.
First calculate the flux from the sun that hits the earth, then the radiative flux emitted from the earth’s surface (a quarter of the incoming flux), then use that to calculate the surface temperature. I get 257 K. I believe Wiki says 252 K.
I can explain how to do it in more detail if you like, but it’s a little awkward to write the equations in the comment box…
On the space station, the sky is black and the sunlight is white. We can estimate the temperature of the surface on the Sun by it’s color – or a surface temperature of approximately 5000 K.
If we use apply this estimate to approximate the temperature of the Earth from the Voyager 1 spacecraft, Earth would appear as a “blue dot” with a surface temperature of of 6000 K.
The temperature of the Earth’s core is approximately 6000 K.
When applying the Stefan-Boltzmann Law, you don’t get to cherry pick the surface and the heat sources.
That is for a planet with zero atmosphere, and zero oceans yes?
Any planet with an atmosphere, GHG or not, has increased heat capacity and a residence time for that energy entering the atmosphere. The entire time surface energy is conducting into an atmosphere, instead of radiating to space, the energy is increasing above the Stefan – Boltzmann constant. The TSI is constant, 24 – 7 – 365. Yet any material that increases residence time of incoming TSI, increases the total energy in the system, as while that heat capacity is filling up, energy within the system is increasing. The oceans and atmosphere add additional energy into the system via there energy capacity, which is determined by the residence time of the energy received.
The same is true of the oceans, as the residence time of solar TSI striking the oceans is extremely variable, from almost instant reflection back to space, to centuries. So the oceans, containing a thousand times the energy of the atmosphere, must likewise increase the energy content of Earth’s system.
So the surface atmosphere is receiving not only TSI which reaches directly reaches it, but back convection from the convection warmed atmosphere, and the solar warmed oceans.
David, what in your opinion makes the better case for (or indeed against) climate change theory? Is it ECS or absorption rates?
Both of these ‘cards’ are played heavily by alarmists yet both appear to have significant weaknesses which also compromise AGW theory.
The critical factor is the strength of the CO2 and H2O absorption spectra, particularly H2O. They quickly absorb a high proportion of the outgoing radiation leaving little opportunity for further absorption and hence global warming.
David Coe wrote
“as the residence time of solar TSI striking the oceans is extremely variable, “
Above you spoke of the residence time of energy absorbed by the oceans.
The residence time of a CO2 absorbed photon has often been written as some not too many microseconds. That, however, is not the full greenhouse effect story; the idea is that the photon goes from one CO2 molecule to another many times, increasing its time within the atmosphere.
Regardless, there must be an average residence time within the atmosphere. A dangerously daytime hot desert environment can go th hypothermia temperatures pretty rapidly once the sun goes down, suggesting the residence time isn’t all that great. Of course the surface of the earth varies greatly from place to place; much of it is very unlike a desert but it isn’t CO2 that makes a desert. It isn’t CO2 that makes clouds or raindrops.
Has anyone come up with a value for the average photon’s atmosphere residence time due to CO2? If that is seconds, or even a few hours, it would seem that CO2 must be of little significance in the overall temperature picture because its effect could not be sustained throughout the shortest night.
David Coe,
[70% of the energy radiated from the earth is removed by a mixture of 0.1% H2O and 200ppm of CO2. ]
For clarification please…
Where does the 70% figure come from?
Where does the 0.1% figure come from?
Where does the 200ppm figure come from? And, finally, how do these gasses remove the energy radiated by the Earth? (What happens to the energy?)
Thanks,
Arfur
Yes, I could have made this clearer. From Table 1 the maximum amount of absorption obtained with impossibly high concentrations of H2O(4%) and CO2(3000ppm) is 85%. 70% of this (64% absorption) is obtained with only 0.1% H2O and 200ppm CO2. This energy is absorbed by exciting vibrations within the H2O and CO2 molecules which raise their energy and temperature. In order to maintain thermal equilibrium this energy is eventually reradiated by the H2O and CO2 ,molecules, but only half of this reradiated energy is directed outwards towards space. The other half warms the earth.
but only half of this reradiated energy is directed outwards towards space. The other half warms the earth. ???
Firstly the time between absorption and reradiation is less than one second according to papers i read.
Secondly less than half is reradiated towards earth (there is a sideways component). And this reradiation is at lower energy.
Third, this reradiation cannot ‘warm’ the earth. Second law of thermodynamics. The radiation from the earth is passing from a hotter to a colder body (CO2). The colder CO2 object cannot pass energy back to a hotter Earth object.
So the reflected radiation from the Earth is momentarily absorbed by CO2 and then released on its path to space. Some bounces around downwards and sideways at reduced energies before finding a path to space.
CO2 merely has a slight delaying effect on earths cooling – it does not ‘warm’ the earth but delays atmospheric cooling to a miniscule degree. Hence on a cloudless (low H2O) night it gets cold quick (despite all that CO2). But on a cloudy night the H2O blanket insulates us well with the same amount of ineffective CO2 doing sod all insulating.
I think you’ll find that cold bodies do radiate even to hot bodies. Of course hot bodies radiate more back just to keep the second law of thermodynamics happy.
David,
See my earlier response to you further down the thread.
bobn is absolutely correct is his statements. There is no mechanism whereby adding CO2 to the atmosphere can significantly warm the surface. Over half of the radiation from atmospheric none-condensing gig molecules is away from the surface and the delay in any downward radiation being emitted to space is measured in seconds or at most minutes, whereas the addition of CO2 is measured in years (140ppm in 170 years).
Yes, cold bodies radiate to any other body (hot or cold) but radiation is not heat!. That is the mistake you are making.
[“Of course hot bodies radiate more back just to keep the second law of thermodynamics happy.“]. Happy? Heat only flows one way. That IS the Second Law of Thermodynamics (Clausius form). It doesn’t need to feel happy.
It is a model. The numbers are put in to see what comes out.
The ‘greenhouse gasses’ remove [intercept] some of the energy radiated from the surface of the earth and sea by resonance with certain wavelengths carrying that energy –
the molecules are shaken into large vibrations. The gasses would simply re-radiate this thermal energy, except that the molecules of the gasses ‘relax’ too quickly (pass almost all their excess thermal energy to the oxygen and nitrogen). Any thermal energy of the oxygen and nitrogen has to be passed back and forth with the molecules of carbon dioxide and water vapour through molecular collisions until such time as the latter gasses ‘decide’ to convert it back into the same wavelengths (good absorption = good emission). By simple geometry, half of this newly radiated energy tends to disappear into space and half to end up ‘back’ in the surface and be absorbed there the (‘back-radiation’ phenomenon).
It is a dynamic process involving multiple re-radiations and re-absorptions, but it can be approximated by a simple adjustment to overall rates, so to eliminate any explicit consideration of most of the complications. Just think of it as snakes and ladders. You always get to the end of the game.
Compared to the oceans, the atmosphere has very little ability to act as a heat sink – if only because of night and day, and winter and summer. You get a gradient of permitted temperatures thereby, whereby the temperature must drop as you go higher (roughly speaking).
Of course, radiation balance is NOT the only thing that matters. The surface of the sea dumps tremendous amounts of heat energy into the atmosphere by evaporation and condensation processes. This energy is radiated away in exactly the same way as any other energy. Half ‘back,’ and half to space.
That is as good a description as I have seen. thankyou.
Arfur
I did allude earlier in this thread to the fact that Tyndall did not know the nature of radiant heat, and thought that it was analogous to conduction and convection. We know now that, in thermal emission, real heat energy* is converted to electromagnetic energy which then ‘does its thing’ – which is to TRAVEL ( through space or the ether or what have you) until it meets matter which sometimes converts that energy to real heat energy, which process is thermal absorption.
It was perfectly reasonable for science, seeing real heat at both ends of the process, to think that it was real heat in the middle of the process, and call this assumed substance ‘radiant heat’. It is just that this happened to be wrong. Hence any analogy to conduction and convection is also prone to lead to errors.
The main theoretical point is that both thermal emission and absorption are merely SPONTANEOUS processes while conduction and convection are also SWEEPING processes. The Second Law of Thermodynamics has something different to say about these two sorts of phenomena. It says that a spontaneous process involves no change in total entropy and can therefore go freely in both directions and can start and stop, while a sweeping process involves an increase in total entropy and rushes on to a terminal state and cannot be reversed without some sort of ‘penalty’ being paid elsewhere.
To get to the relevant point, you are right to say that a body at a uniform temperature cannot heat (raise the temperature of) another body already at a higher uniform temperature by conduction or convection. And you are correct to say it CAN do it by thermal emission. All it needs is for the system to include an appropriate set of focusing lenses and mirrors and one-way transmission materials. We have all done this with a lens and sunlight burning up a piece of paper. Unfortunately for pedagogy, this involves radiation coming from a definitely hotter body! But this is strictly accidental. If we had a big enough lens we could do it with the infra-red radiation from a glacier. OF COURSE, Nature hardly ever does anything like this, but that is irrelevant. And OF COURSE the act of making lenses and positioning them involves increases in entropy. That is also irrelevant to a demonstration of a fact. Scientific laws are about what is possible, not what is probable or common. And anyway, we are part of Nature. Or at least that is my working hypothesis.
*the macroscopic manifestation of the potential and kinetic energy of the incessant motion and interaction of particles too small to see.
Dave, you can focus DWLWIR with a solar still or solar heater at night.
Where a solar still can boil water during the day, the same does not happen at night.
The object subjected to this focused DWLWIR does NOT get warmer, it gets colder.
By about 5-10C, this simple experiment has been done countless times.
Perhaps you can explain how that fits in to your theory?
David Coe, you stated that “David on’s” comment was well said, and I agree. It fits this: David’s law,; “Only two things can affect the energy of a system in a radiative balance, either a change in the input, or a change in the residence time of energy in the system.”
So in short, GHGs increase the residence time of LWIR radiation from the surface.
However you said this earlier speaking of nitrogen and oxygen…
“They do of course do have thermal capacity, but they gain and lose their heat by molecular collisions and convection within the atmosphere.”
It appears you forgot conduction from the surface? Are you saying that GHGs like WV and C02, via atmospheric conduction are solely responsible for what heats the non GHG atmosphere?
So, assuming an atmosphere with zero GHGs to warm the oxygen and nitrogen, the only means of warming the atmosphere would be conduction, not from non existent atmospheric GHGs, but from the surface. And surface heat energy conducted to a non GHG atmosphere would cause convection, rise to it’s appropriate height, and, via more atmospheric conduction, heat more atmosphere that was not in direct contact with the surface.
This process would continue, a slow heating of the atmosphere, the denser the atmosphere, the greater the heat capacity and residence time of said energy from the surface.
Now it appears logical that a curious thing would happen, the atmosphere, having no GHGs, could not radiate away said conducted and convected surface heat. So, as far as conducted energy from the surface, non GHGs increase the residence time of the Earth’s surface energy, and adding a GHGs to such an atmosphere shortens the residence time of said conducted energy. So we then have GHGs lengthening the atmospheric time of LWIR from the surface, and shortening the time of conducted energy from the surface. According to “David’s Law” assuming a steady state solar input, one must calculate the residence time of each input, times the W-SqM of those inputs, to determine the net affect.
The corralary to “David’s Law” is that ” The only thing that affects the residence time of the energy input, is a change in the materials encountered.
Now at night it appears logical that a dense atmosphere full of non GHG molecules would provide back conductive energy to the surface. It would happen during the day of course, yet visualizing it at night is easier. So, although it would take longer for a non GHG atmosphere to reach its thermal capacity ( vs also warming from contact with GHGs) why would it not reach an equal energy content having no means to cool itself except through contact with the surface?
David Coe, thank you for your time and contemplating my statement and questions. My statements may also be considered questions if you will allow.
A.C. Osborn says something concerning infra-red radiation and water which raises a bit of an unknown:
For water is a special case. The question with it is:
” Can infra-red light – whether part of sunlight or emanating from elsewhere – be absorbed AT ALL by a BODY of water? And how does this issue depend on the intensity of the infra-red light.* ? ”
Note, the question says a BODY of water not water molecules The trouble with water is that is EXTREMELY absorptive of infra-red; and this means, paradoxically, that the energy absorption is so confined to the surface that a possible fate is to be expelled by forced evaporation before affecting the mass of the water. In effect, a perfect absorber might just as well be a perfect reflector!
Basic physics gives an instant and definite quasi-answer to the question. It says, it all depends!
Very intense radiation falling on water will boil off a skin of water instantly,
before any energy can be lost to the inside bulk.
Weak radiation will not make anything boil away before the heat goes from the surface to the inside bulk, and warms it. The heat does not have to go far; just far enough that the surface is much as before for emission and evaporation purposes.
There is an analogy with a thread attached to an iron ball on a table. If you pull on it gently you can make the iron ball roll. If you yank on it, the thread will break and no energy will be transmitted from you to the iron ball. Paradoxically, then, you can do more work with the smaller force.
But what counts as intense and what counts as weak in a given situation?
It is very interesting that the Globe’s net transfer, from the sea surface to the atmosphere, of heat, by means of evaporation and subsequent condensation in the air, is similar to the total amount falling on it from all infra-red sources. So, in this world of ours, is infra-red input simply ineffective with the sea?
I have looked into this interesting question, by searching the literature, and speaking to a few specialists, and found that virtually zero work on it has EVER been done. I have some experiments in mind, which I might actually do one day!
Perhaps in the case of a boiling solar still, all the energy ABSORBED during the day comes solely from the visual spectrum and not at all from the infra-red part of the sunshine.** In that case, it would not be surprising that the temperature of the water drops at night, what with the only radiation coming in being infra-red from a cloudy sky – whether intensified by gathering or not.
* Not the energy per photon but how MANY of the appropriate photons, in a given energy-range, are impinging on a unit of water surface.
** About half of the total energy, incidentally.
Dave on, you said, “Not the energy per photon but how MANY of the appropriate photons, in a given energy-range, are impinging on a unit of water surface.”
Please read my comment just above in consideration of residence time. Because if the residence time within a given system is very long, a small input of energetic photons will eventually raise the entire content ever closer to that energetic excited state.
Fir illustrative purposes imagine a large 100 sq’
base of a giant pot. The water in the pot is the “system” just as the earth surface, oceans and atmosphere are our Earth’s “system”. Now the input into the pot may be nice comfortable 75 degrees over the entire surface. No matter how long the residence time of said energy of the water within the pot, the water in the pot will not go above that 75 degrees yes?
This is true even if the residence time of energy within the pots “system” is infinite. Now let’s change the input, not to more total energy, but to all that energy in an extremely excited but small one square inch area, say 700C flame, center of the pot, and only that one square inch has a thin metal area, the rest is vastly thick, giving the theoretical pot inner ” system” nearly infinite residence time. The rest of the outer surface of the pot can be very cold, so that the total watts per sq meter input is the same as before. Yet, due to the very long residence time, the one sq inch input of very energetic molecules can bring the water to an eventual boil, which the same total watts per SqM 75 degree ambient air can never accomplish.
The purpose of this is to support my supposition that eventually a non GHG atmosphere of equally dense gases to our current Earth’s atmosphere, will EVENTUALLY warm the same as a GHG atmisphere to reflect the energetic energy of the surface, as a non GHG atmosphere has a far longer residence time of conducted surface energy then a GHG atmosphere. GHGs shorten the residence time of conducted energy input, while they lengthen the residence time of LWIR.
Your thoughts appreciated. David Coe’s as well of course.
EVENTUALLY, an atmosphere of nitrogen gas lying on top of a large uniform heat source at 75 C with a uniform surface, would also attain exactly 75 C., by slow conduction if nothing else.
As a thought experiment it seems clear that a warm earth surface and a cold atmosphere of nitrogen and oxygen could not coexist on a geological time scale. Especially, if you allow for the possibility of convective mixing which is inevitable for a spherical planet (surface at the equator warmer than surface at poles). Which would negative the assumption of a uniform heat source.
But we have water on our planet in all its physical phases, and that is an over-riding consideration.
I use LWIR lasers (10.6 um wavelength) in industrial processes, usually to melt steel (~1500C). They can also boil water.
It’s interesting what happens with water, because the energy is absorbed in the top surface layer, so it boils “from above”, when we are used to seeing it boil “from below” as the energy is added to the bottom of the vessel.
But the IR radiation is most certainly absorbed by the water, adding energy to it that would not be added in the absence of the IR.
Most rocks absorb shortwave solar radiation in the very thin top surface layer. Are we to conclude that sunlight cannot “heat” rocks?
dave January 19, 2021 1:09 pm
When I say the water in a solar still cools at night, I mean below ambient, up to 10C below ambient.
A C:
There are several issues you haven’t considered with your “solar still” example.
First, the DWLWIR is diffuse, coming from many directions – not almost parallel as with solar radiation – so it cannot actually be focused at all.
Second, the less the level of DWLWIR, the more the water gets below ambient air temperature at night. That’s why you can get ice on puddles overnight on a clear night at +2C, but not a cloudy night at the same temperature.
If you look carefully at sunrise following one of these clear nights that doesn’t quite get down to freezing surface air temperatures, you will see ice on surfaces directly exposed to the sky, but not on surfaces under trees and other overhangs.
When I studied engineering heat transfer many years ago, we learned as a rule of thumb to treat a clear night sky in temperate regions as radiating equivalent to a blackbody at -20C (253K). That’s cold, but MUCH hotter than space about the atmosphere, which radiates as a blackbody at -270C (3K).
Nothing you assert provides any evidence against Dave’s arguments.
Thanks for the dialogue, you say
“EVENTUALLY, an atmosphere of nitrogen gas lying on top of a large uniform heat source at 75 C with a uniform surface, would also attain exactly 75 C., by slow conduction if nothing else.”
I agree. Would the surface not then also receive, well let’s call it back conduction? This would be most noticeable at night, as the atmosphere, sans GHG, would only cool through conducting energy to the surface, where some would then become LWIR, zipping more rapidly to space, and some would re-conduct back to the surface atmosphere. @
Continuing our experiment, let’s add five CO2 molecules to the nitrogen oxygen atmosphere. One acts just like all the non GHG molecules, receiving and transmitting energy via conduction in the lower atmosphere where collisions are much more rapid. Thus it is net nuetral to warming or cooling. The 2nd CO2 molecule, higher in the atmosphere, bumps into a warmer rising nitrogen molecule, and upon receiving that energy it radiates in a random direction, this time into space, thus shortening the residence time of atmospheric energy, which = net cooling. ( also this serves to increase the gradiant of the lapse rate via cooling that layer of the atmosphere) The third CO2 molecule does just as as the 2nd, only this time it randomly redirects the conducted surface energy back towards the surface, thus warming. Now we come to the fourth and fifth CO2 molecule, and they do something quite different. They takes the LWIR from the surface and either redirects it back towards the earth, thus warming, or towards space, thus cooling compared to a non GHG molecule.
Now the T of the surface area conducting to the atmosphere can be quite warm, well over 100 degrees F, and, if conducting to a nitrogen and oxygen molecules, it will vigerousely energise those molecules. So, as you say, it will, over increased time compared to GHG LWIR and conduction absorbing atmosphere, warm it to the mean surface T. After all it’s heat capacity is equal to a same density atmosphere that also has GHGs. So like the long resident time pot ( non GHG atmosphere) with the single hot flame input, ( solar heated surface) the non GHG atmosphere will eventually reach the surface temperature and send that energy back to the surface via conduction.
Only two things can change the energy of a system in a radiative balance, either a change in the input, or a change in the residence time of energy within the “system”.
Now you added the ocean into the discussion. My we have complicated things. I perceive the oceans as a liquid green house fluid. I think the net affect is clearly energy positive, as they greatly increase the residence time of Solar input. And not by a little bit like CO2 does with LWIR, but by a great deal with a TSI residence time of up to a thousand years. And they clearly keep the atmosphere far warmer at night.
Ed Bo January 20, 2021 12:59 am
Sorry, your explanation does not explain why the solar still is so much colder than ambient and the surfaces all around it.
As to focusing DWLWIR, I suggest you go back and read Dr Roy Spencers experiments on this subject, he added a “collector” to his design to increase the effect. ie the same as a solar still.
HIs conclusion was that the CO2 made it warmer than it would be looking at open space, but of course it can’t, it is looking at the Atmosphere above it.
Yet not in a non GHG atmosphere yes? Then said energy, plus conducted surface energy to the non GHG atmosphere would only leave via LWIR radiation. And once said energy is transferred to non GHG molecules, that LWIR would not be occurring yes?
AC: As I have said multiple times before, it is a common natural phenomenon that the surface can be several degrees below ambient at night. This occurs especially when there is a direct radiative connection to the cold upper atmosphere (clear, low humidity, unimpeded view) and limited thermal connection to ambient (still air in particular, but also low conductive transfers).
In an engineered system, you want to maximize this contrast. I could not find the particular post you cited at Roy’s blog (a link would have been good), but the same collector that would optimize heat “gain” under the sun would optimize heat “loss” to the night sky, and further minimize thermal transfer with the warmer ambient.
David Coe? Did you try to get your manuscript published in a conventional journal whose editors use peer-review? It would be instructive to learn their reactions to your paper, especially if it was rejected out-of-hand…a common problem with some high-profile outlets. Peer-review works well when the topic in not very controversial. Otherwise it falls into the hands of conventional wisdom and orthodoxy… where it fails.
No I have not. That would be a waste of my time. In any case who reads scientific journals on climate change other than committed so called scientists. This is not written in a style for scientific publication. It is written for a wider audience. Climate change is political not scientific. I am simply trying to offer understandable reasons why CO2 is not causing the problems claimed by the intelligentsia.
David…I certainly understand, but others have tried and failed by using simple logic and the geological and geochemical record going back in the early Archean when levels of CO2 were more than double those of today and life was evolving and thriving. Even a lower pH was not damaging to marine carbonate plankton.
One suggestion for the wider audience? would be not to use temperatures in °K, which very few can readily recompute to the °C or °F they are used to. Current mean temperature of 288°K is 14.85°C, and in the US it is 58.73°F
Thanks to Paul for giving us a chance to read it and ask questions. Were this the norm the current ‘climate emergency’ and global warming hysteria might never have taken place.
David
Nice article.
Unfortunately peer reviewed journals is where those that want to persuade their fellows, and in turn influence the policy makers, have to turn. If it is not peer reviewed then as far as scientists and the govt and the MSM is concerned, it is yet another piece of ill informed unscientific scepticism,
Sceptics do not have the ear of anyone with the authority to change our damaging policies.
It would be useful to see this article also at WUWT where there still lurk many with a scientific background.
Then if you want to make an impact you need to rewrite taking into account any valid criticism and see if you can stop western humanity from jumping over the economic cliff by getting it published! No pressure.
DAvid Coe,
Regarding my earlier question about radiation from O2 and N, my sometimes slow memory brings up that it is O2 radiation that satellites measure for temperature. While these photons are less energetic that CO2 radiation, there is over 500 times as much O2 as CO2 in the atmosphere. This suggests that, if CO2 is responsible for major radiation to space, the much larger number of O2 photons radiated to space might not be insignificant in regards to cooling the atmosphere.
This is a fascinating piece which, as a layman, I struggled to understand fully. Can someone please summarise it in simple language which I and others like me, and especially school-children, can understand?
There is no climate crisis.
Modest amounts of natural warming have been wildly exaggerated into a manufactured but non-existent ’emergency’ by activists, alarmists and those who stand to gain professionally, financially or ideologically.
There’s now too many people and organisations with extremely vested interests to allow this racket to be derailed.
I think I’ve got this. I think this would work on Kids. Peer review please.
CO2 and H2O are very good at absorbing heat that is radiated, or reflected from the Earth’s surface after the sun has heated it.The radiation of heat from the Earth has a waveband range, called a spectrum, of say 1-100 which can be calibrated by spectrum analysis gizmos. Part of this range can be picked up by CO2 and H2O and they absorb that part of the heat. That heat can then be transferred to nitrogen and Oxygen which make up the bulk of the atmosphere. This heats up the atmosphere which can reflect heat back to Earth. CO2 and H2O can only pick up part of this spectrum and they do it very well. The present levels of CO2 and H2O in the atmosphere do it so well that there is very little left after they’ve finished. They do it so well that adding more CO2 and H2O has very little effect. Its like mopping up water with blotting paper after you have spilt some. It works very well until the water has almost all gone and adding more blotting paper has little effect.
Well it works on me!!!
Wholesale defection of many people from FB / Twatter etc to Gab.com telegram and others should be a route to some new minds? Although many of those seem rather skeptical already…
David,
After a quick read of your piece my questions are:-
[1] Are you in agreement with the expected 1C warming from a doubling of CO2 from 280ppm to 560ppm (or 300ppm to 600ppm depending on whom one reads) applying Stefan-Boltzmann and BEFORE FEEDBACKS due to H2O and clouds?
[2] Is the 1C correct? Everyone seems to use this figure although Judith Curry describes it as “canonical” inferring she and others have doubts. [I understand the climate models come up with 1.2C]
[3] What do you think of the IPCC’s claim that including water vapour feedback with the effect of the CO2 doubles the warming?
This is another piece of work that leaves out the effect of radiative gases on lapse rate slopes and thus convection.
The truth is that convection responds via changed lapse rate slopes in order to neutralise radiative effects and thereby retain hydrostatic equilibrium:
https://www.newclimatemodel.com/neutralising-radiative-imbalances-within-convecting-atmospheres/
The greenhouse effect (so called) is a by product of convective overturning within the mass of an atmosphere and nothing to do with radiative gases at all.
http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=166&doi=10.11648/j.wros.20200901.13
Although the above paper refers to Titan, the principle applies to all bodies with convecting atmospheres.
Your papers appear convincing.
Agree. People might like to consider how the temperature on Earth would respond if the surface had the same atmospheric pressure as the surface of Venus i.e. 92 bar (Earth currently 1 bar), regardless of the constituent gases.
Venus has the complication that the lower layers of CO2 are in fact supercritical liquid (i.e. above 74 bar and 31C) rather than being in the gas phase. That makes them considerably denser, and almost like a sea from the perspective of heat transfer by radiation and convection.
David. I am always concerned by statements such as “The atmosphere however will reradiate this energy in all directions, with the effect that half the energy will be directed back towards the earth, thereby warming it further, while the other half will be radiated outwards into space.” The cool atmosphere cannot heat the warm earth. What happens is that the T^4 factor reduces the rate of radiation form the earth, which is thus warmer than it would be without the atmosphere reducing the radiation. Could you not reword the statement to make it clearer?
I am not disagreeing. The main point however is that the earths temperature is determined solely by the heat balance at the “top” of the atmosphere. The effect of atmospheric absorption is that less energy is transmitted through to space, thus causing the earths temperature to increase. I have specifically ignored what happens in the atmosphere in this simple model other than that radiated energy is absorbed and retransmitted. For me the important point is that this simple model predicts very closely the equilibrium temperature of the earth with actual mean earth temperature and further suggests climate sensitivity almost an order of magnitude lower than the “experts” models.
Yes the infinite details of a chaotic system like the atmosphere are important. But the resulting variations are called weather.
OK, I agree that the earths temperature is determined solely by the heat balance at the “top” of the atmosphere, but it is still wrong to claim that the back radiation warms the earth. The radiant energy from the sun can only heat the earth once. Once it has been radiated back upwards, it cannot be radiated back down from the atmosphere and heat the earth a second time (or ad finitum). The earth’s energy budget, such as that of Trenberth and shown diagrammatically on lots of alarmist websites, are totally wrong.
David, please see my comments above, in response to David on’s comments. I think you are forgetting conducted energy from the surface, and it’s greatly increased residence time in a non GHG atmosphere.
Indeed that is so, and Trenbeth et al. get it all wrong because they do not understand the very basic difference between energy flux and energy.
Energy fluxes do NOT have to balance for any period of time. Ultimately they eventually will in the very distant future when all matter reaches a universal equilibrium.
Energy, at any moment of time, does always balance!
tom:
Let’s look at the basic equation for the 1st Law of Thermodynamics for a system:
DeltaE = Sum(EnergyFluxIn) – Sum(EnergyFluxOut)
where DeltaE is the change in the energy of the system over the period in question, which is equal to the difference between the input fluxes and the output fluxes.
In differential form, we state this in terms of power:
dE/dt = Sum(PowerFluxIn) – Sum(PowerFluxOut)
Where dE/dt is the rate of energy change in the system, equal to the difference between the input power fluxes and the output power fluxes.
While it is true that these fluxes do not NEED to balance exactly, not even the worst alarmist thinks the earth is more than a small fraction of 1% out of balance.
The input power flux from the sun is about (240 *Aearth) watts, known to about 1%. The output flux radiated from earth to space is also about (240 * Aearth) watts, known to about the same precision. (Aearth is the surface area of the earth). We now have good satellite measurements of these quantities.
“Alarmists” think that the imbalance is about (1.0 * Aearth) watts – Kiehl & Trenberth say 0.9 (they do NOT assume a balance). “Skeptics” think the imbalance is closer to 0.0 than to 1.0. That is where the interesting arguments are.
Yes to that Ed Bo,
but Kiehl & Trenberth model is based on a false notion (an assumption) that energy flux leaving the earth is the same as that from the sun, (averaged over any period of time). This planet’s natural condition is far more complex than their over-simplistic model allows. Kiehl & Trenberth model implies that the nonsense of ‘back-radiation’ provides the majority of energy for the weather and climate change. NO! The atmosphere optically thickens as it goes from the TOA to ground level so preventing ‘back-radiation’ penetrating very far, and with no upper atmosphere ‘hot-spot’ CO2’s effect must be negligible.
Of note is as the planet warms life across the globe expands — it sequesters more of the solar energy while exchanging more gases and matter in the carbon cycle. Witness the expansion of the greenery invading the deserts ( see https://www.livescience.com/62168-sahara-desert-expanding.html ). What is powering that expansion? As more of the deserts greens-up so more productive soil is made — soil that better retains daytime solar heat overnight, significantly better than sand.
Also vast algae and plankton blooms on the seas’ and oceans’ surfaces happen more often (see https://www.phenomena.org/ocean/algalbloom/ ) during warm periods. Some which when it dies rains down to the oceanic abysses taking it’s parcel of solar energy with it, and staying deep in the oceans for thousands if not millions of years.
Historically during warm eras life was more prolific right across the planet.
During the cooler periods most life recedes and dies back, only the warmer areas of the world retain major enclaves of life. Deserts expand, while in other areas the chill results in almost lifeless frozen tundra and glaciers.
Thankfully we are out of the Little Ice Age when life had a much more difficult time, and now we’re in a warmer age — but for how long?
IMHO, IR radiative affects of atmospheric gases are only a part of this planet’s climate story — overall changes in humidity (cloudiness) and air pressure also have their bits to play. However nature and life, and how it responds also has large part to play on how climatically the planet changes.
Lastly, ‘The Rational Climate ebook’ that appears to hold on to its scientific sanity better than most in the climate debate —
https://www.researchgate.net/publication/347150306_The_Rational_Climate_e-Book
I can only repeat what I said earlier, that K&T explicitly say that the incoming and outgoing fluxes do NOT match exactly, contrary to your repeated statements.
The 1st Law states that any imbalance in these fluxes must show up in the change in energy content (dE/dt) of the earth. By far the most important of these is Ocean Heat Content. Everything else is dwarfed by this. And the OHC measurements from Argo, which many skeptics think show too much warming, still show only a tiny fraction of 1% — less than 1 W/m2 overall — imbalance between incoming and outgoing fluxes. Again, they do NOT assume the fluxes are the same.
You say: “The atmosphere optically thickens as it goes from the TOA to ground level”, which is true, but you draw exactly the wrong conclusions from this. In Roy Spencer’s post:
https://www.drroyspencer.com/2010/07/yes-virginia-cooler-objects-can-make-warmer-objects-even-warmer-still/
the fourth figure shows graphically the implications of this, showing that the DWLWIR gets STRONGER as you go from TOA towards the surface — and yes, we have measurements that confirm this.
David Coe; An excellent paper. As an engineer with 10 years experience of IR spectroscopic trace gas detection, I have always been suspicious of the IPCC ‘science’, so set out to investigate.
Using HITRAN and atmospheric radiative transfer models which I hope will be beyond critisism by AGW acolytes, I hope to publish something later in the year once I am certain that I am using the models correctly. Results so far align well with your own.
If you would be interested in ‘comparing notes’ (in more detail than is perhaps appropriate here) I am more than happy for Paul to pass on my email address. I would welcome an opportunity to discuss, as there are very few out there to ‘bounce’ ideas off.
Yes I am totally happy for Paul to pass on my contact details.
Cyan
My email address is coecharlesdavid@gmail.com
A fascinating read David. Although those mathematical equations leave me cold, the diagrams and graphs do not. This retired Chemistry teacher always assumed that if you double the CO2 concentration you double the amount of IR absorbed, the same for Water Vapour. Wrong again. Clearly its a “whose eaten all the pies” scenario where a small number of (greedy) CO2 molecules help themselves leaving little radiation for the rest.
Short shrift given to N2O, meat eating and methane, don’t think Prince Charles will like that!
We will soon be going over to the Hydrogen Economy (bear with me) and I’ve forever questioning why change from one g.h.gas, CO2, to another, WV. But now I can see that the extra WV produced will not have much IR to absorb anyway. You live and learn.
Any warming effect from added CO2 exponentially decreases as CO2 increases, while all the benefits of C02 increase in a linear manner.
In affect, the failing to manifest projected harms, increase less with each additional C02 molecule, and the KNOWN massive benefits increase just the same.
If CO2 can significantly delay IR radiation from leaving the atmosphere, how, mechanically and/or logically, can more CO2 not delay it longer? Suppose the H2O, CO2 and any other absorbing gas concentrations in a parcel of air are such that absorption of IR photons entering that parcel are 100%. Add more CO2 molecules.
Those absorbing molecules are only temporary IR care takers. Sooner or later they emit IR, which hopefully eventually makes it to space and is gone. However, the more CO2 in that parcel, the greater the probability that the emitted IR photons will not leave the parcel because there are other CO2 molecules to capture them first. The more CO2, the denser the CO2, thus the shorter the IR photon free travel path.. Of course when looking at the entire atmosphere, the probability of recapture becomes even greater.
Biden, Boris ad Co are due to meet in Cornwall later this year to discuss climate change among other items.
Should we hope for a still and cloudy few days to highlight the drawbacks of their plans for power generation?
Well done, David, and well done, Paul for publishing it.
Regarding comments concerning O2 and N2 radiation.My understanding is that any gas above _273 C,will radiate to some degree.
I read a paper by Japanese scientists(I think) sometime ago,that while N2 and O2 radiate little across most of the atmos.,at the North Pole they did indeed radiate a much larger percentage.
This was believed to occur because the Tropopause is so very close to the ground there,and somehow enables N2 and O2 to do their bit.
I will try and recover the above paper.
With regard to Gerlich and Tseuchner inwhose paper they mention Hottel and path length.Hottel stated that at atmospheric temps., CO2 has no effect whatsoever.Schach was mentioned in the G&T paper that only at combustion chamber Temps of 3000-C,would have any effect.
On “Tallblokes Talkshop”, dated July 27,2010,Professor Nasif Nahle
“nails the radiative physics of CO2”,and does the maths for path length.You will also find Hottels equations in the Engineering Handbook;a mighty tome.
To Paul;Inote that Fritz Varenholt is now on the GWPF list of members.The Schsch paper mentioned in G%T above is in German.Would it be worthwhile to ask if he could obtain a translation to assist in our deliberations.
Thankyou.Ed.
A very informative article David. You appear to be in agreement with the views of Professor Richard Lindzen and he’s not a bad fellow traveller to have on board!
Great info on the climate sensitivity, David. The value of this seems to be very much a matter of opinion, depending on the estimated transmission factor for the gas. I have worked on thermal radiation from gases in boilers and furnaces and Have found similarly low values for the sensitivity to concentration.
Another factor, which also affects IR spectroscopy, is the interaction of water vapour and CO2. This has the effect of making the emissivity of the two gasses non-additive. The emissivity is less than the sum of the two individual contributions, in some cases by a long way. I think that Codel correct for this effect in their cross-duct units?
The climate modellers assume simple additive values, too high an ECS and a purely hypothetical feedback to create their fear campaign. Also, the topic of gas radiation / absorption is not easy for non-specialists so they do not question the “proven science”.
The key to understanding the interaction effects of gas spectra, is to think in terms of transmissivity T which is equal to 1 – absorption. The total transmissivity of two gases is simply the product of the two transmissivities at any given wavelength of the radiation.
T total = t1 x t2
Thank you for your reply, David, you have had a busy day!.
This does not seem right to me, for the water CO2 mixture. There is an effect that is not fully understood where the emissivities (i.e transmitivities) are not simply additive and this effect is also important in IR spectroscopy. They are simply combined for diatomic gas mixtures.
e(combined)= 1- t1x t2 = e1+e2-e1xe2 is the simply additive form, but the correction to (e1+e2) is far bigger than e1xe2 for CO2 +H2O and depends on the partial pressure of each gas. We still use graphical methods to calculate the reduction in emissivity for mixtures!
CO2 detection by IR in samples requires the gas to be dry for this reason (Keeling method), and makes me suspicious of the ice-based figures that are so widely used for historical CO2 levels and the rejection of earlier gravimetric analyses.
Re: the chilly 255K of the estimated zero atmosphere condition
According to the Diviner data 197K is the actual average physical surface temperature of the Moon, which meets the condition.
I believe the difference in effective temperature between the earth and moon is caused by albedo or reflectivity. The earth because of the large area of ocean which readily absorbs radiation has a very low albedo. The moon on the other hand has a significantly higher albedo thus reducing the level of energy absorbed from the sun. This gives rise to a lower effective temperature.
The moon’s albedo is 0.12, a lot lower than the Earth.
https://www.universetoday.com/19981/moon-albedo/
Oldbrew, that being true certainly highlights the importance and warming affect of an atmosphere!
Yet the residence time of SI entering the oceans is vastly longer then any moon surface absorbtion of SI yes?
So the vast energy content of the oceans, representing months or years of accumulated
solarr input, if on the lunar surface, would keep the night T far higher, and far higher again if there was an atmosphere to radiate into?
David, thank you for your reply but your final conclusion is not possible. Yes the molecules absorb some of the emitted long wave radiation but any consequent re-radiation back to the Earth has no thermal value whatsoever. Molecules at the Earth’s surface will not have their internal energy raised by the so-called backradiation because the backradiation does not possess enough energy to do so. After losing energy through low energy collisions, any remaining radiation emitted (or even ignoring this aspect) from a ‘cold’ atmospheric molecule (I know molecules don’t have temperature per se) cannot warm the planet. So the backradiation energy will likely be reflected or transmitted, probably the former. The energy will therefore be emitted to space, even if delayed very slightly. There is simply no physical mechanism that radiation from a CO2 molecule can warm the surface unless the surface molecules have less internal energy than the CO2 molecule.
Regards
One aspect of IR radiation often cited is its measurement by an IR thermometer pointed at the deep night sky. A rather low temperature by human standards, around -60 C, is measured quite consistently. That measurement is made using the IR photons coming down from the sky. Those photons must interact with the much higher temperature thermometer. They impart energy to it and that energy is used to make the measurement.
IR thermometers are not special in regards to IR radiation. Any object, the earth itself, absorbs those IR photons just as readily. When energy is absorbed, the temperature of the absorber rises. That falsifies your claim. The temperature probably cannot rise very much by way of the energy from a -60 degrees C source – unless there are a great many photons. If the photons are focused to a very small area the local effect on temperature will be much greater even though the individual photons have no more energy to impart.
Something happens when the energy is absorbed and the temperature rises. The rate of emission from the absorber increases as the fourth power of the temperature increase. This, it seems to me, explains why the temperature rise is never very much when a colder source radiates to a warmer one. The warm one always radiates at a faster rate than it absorbs.
I don’t know the details of the physics but they exist and are invariant regardless of my considerations. How fast does the temperature raise compared to how much faster it falls because of the increased rate of emission? There is a dynamic balance there. It is whatever it is, it isn’t up for a vote.
It may rise faster than the cooling effect of its 4X increased rate of emission. If that is true, and the exchange occurs for a long enough time, the temperature will rise significantly. Or, its increased rate of emission may prevent the temperature from going up very much, relative to the temperature difference of the sky source, regardless of how long the radiation is maintained.
David, my last comment was in response to your reply at 2:49pm on 17th Jan. It didn’t save in the reply box.
Arfur
Have any large scale experiments been done to settle the matter? I am thinking of a day 30m long highly insulated pipe, if possible vertical, containing air with typical water vapour but injecting additional CO2 from 200 ppm up to 1000 ppm. Sensors at the ends and a radiant surface at the lower end, heated between 0-50 deg C. Perhaps use the type of sensors that you manufacture.
Omit ‘day’. Predictive text error.
Unfortunately Steve. This is not as easy as it sounds. The principle problem is that the source of IR energy must match the profile of the earths radiated energy at 288K for the tests to be meaningful. Unfortunately we are surrounded by that energy at all times, so it would be impossible to differentiate between the energy from the source and background energy. The Hitran spectra data base does provide accurate data to enable calculation of the absorption effects of the atmospheric gases, without having to do the experiment.
That’s why I suggested that the test would be highly insulated. If an experiment could be done by which the additional CO2 could be pumped in and the transmission measured at the same time, then it would be harder for the computer modellers to keep on claiming that their calculations are correct.
Those tests have been done, I would direct you to the original tests, but it is a very long read.
There is also real world test where natural CO2 varies during the day and it does not show increasing temperature with increasing CO2.
Let me know if you want the link to the big read on testing.
Don’t get too excited folk. There are some big problems with the document.
1. “The higher the temperature the higher the water vapour concentration.”
No. By that logic deserts would be very humid places. The higher the temperature the more water that COULD be held in the atmosphere.
2. “These gases have the ability to absorb the outgoing infra-red radiation from the
earth, and act to reduce the amount of reradiation into space, thus increasing the earth’s
temperature.”
No. If absorption (i.e. trapping) caused warming then even a warming 0.01C per century for the last 4.5 billion years would mean the Earth would be so hot that it was uninhabitable. GHGs only slow the release of heat into space, at least they do down in the lower troposphere.
3. The document doesn’t contain the words “cool” or “cooling” but of course the atmosphere cools. It does this via CO2 in the stratosphere (still at about the concentration at the Earth’s surface) and by H2O in the upper troposphere. When the concentration of CO2 increases there’s increased absorption but also increased loss of infrared energy.
4. Nitrogen, oxygen and argon don’t absorb radiation but that doesn’t mean they have no impact on temperature. They are important for circulating the heat that GHG’s firstly absorb and become “excited”, then lose when they collide with molecules of one of these three gases. As the density of gases decreases with altitude this circulation of heat energy reduces because collisions are less frequent. And by the way, when these three collide with GHG molecules that are not “excited” the energy goes to the GHGs which might then radiate it.
+100
Every night the earth sheds the heat from the previous day, every winter it sheds the heat accumulated during the summer.
What it can’t shed so easily is heat stored in the oceans well below the surface by UV and white light radiations which create the El Nino events.
On point 3, the simple premise, as I understand it from the article and various comments, is that there is only a certain amount/level of infra red radiation once that has been absorbed the co2 concentration levels are, by en large, irrelevant!
John, regarding 1. The earth is 70 percent plus water, so in general an increase in GAT will increase WV. yes? And yes, increased clouds us, IMV a net negative feedback to warming.
Regarding two, anything that increases the residence time of energy within the system, increases the net energy.
Regarding 3. True, and Dave C mentions that. Steve McIntyre long requested an engineering style work sheet on all the pluses and minuses of the purported GHE. Yet with major factors such as clouds and ocean residence time of disparate SW radiation poorly understood, we simply do not have that paper.
Regarding 4. Nitrogen and Oxygen do absorb conducted heat from the surface, and from the oceans the receive both conducted heat, and energy from WV via conduction and condensation. And unlike the very cool T of CO2 radiation, this is often very energetic, 100 F plus. So for all conducted heat and WV heat released into the atmosphere from Earth’s surface, any GHG is net cooling.
Question:
Should you not allow for the location of the TOA in assessing the radiation balance? For simplicity take R(earth)= 4000 miles, TOA sphere for radiation at 200 miles above the surface, so the dip to the horizon below a tangential plane is acos(40/42) in all directions, so you have (π-2acos(40/42))/2π as the share of downward radiation, and (π+2acos(40/42)/2π as the spaceward share, with perhaps a small correction for atmospheric absorption in the downward direction between the horizon and the tangential plane. Here the real altitude of the effective radiative shell matters, and it is not the same as the nominal thickness of the atmosphere for the purposes of absorption calculation. Even with the TOA at 50 miles the split becomes about 55/45 instead of 50/50 that you assume.
Yes, I agree. This is one of numerous arguments against assuming a 50/50 split between absorbed radiation being transmitted to space and retained in the earth. I think perhaps I need to do a brief follow up paper to show the impact that changes to that 50/50 split would have on equilibrium temperatures and climate sensitivity so we can put things into perspective.
It’s probably not too hard to estimate the element of atmospheric absorption I referred to by considering the atmospheric density modelled as an exponentially declining density with altitude. Integrate along chords of the TOA sphere in the relevant angle to find the effective absorption thickness along a chords and across the dip angle. Chords that are almost tangential to the horizon will have a lot of absorption, but shallower ones will have little.
A more sophisticated approach looks at photon mean free path more explicitly, but I doubt it improves the calculation accuracy by much given the uncertainties.
More sophistication based on measurement
https://www.mdpi.com/2073-4433/11/1/75/htm
The mean free path of CO2 LWIR Photons is the point that climate scientists do not want to talk about, as it destroys the narrative of stratopheric CO2 warming the Earth’s surface.
They also do not want to talk about Energy Density of Solar Radiation versus LWIR. at -50C.
They don’t want to talk about the time for a CO2 molecule to release a photon compared to the time to collision and kinetic transfer.
It seems to me that the altitude where outgoing radiation is mostly all outgoing is generally cited as around 15 km.
The point the Alarmists make when confronted with such work is that the temperature is rising and if it’s not CO2, what is it?
Of course that’s not a scientific ar6as the underlying assumption is that we know everything about the climate, which is fallacious. However it is an argument that convinces many who are unscientific and/or not very good at thinking (i.e. most politicians). Thus until we can show an alternative, convincing explanation for claimed changes, the CO2 narrative will stick.
The problem here, as Paul repeatedly demonstrates, is that there is no evidence for exceptional warming above the natural cycles, other than the propaganda by the BBC, MSM and the likes of Attenborough.
if it’s not CO2, what is it?
Consider the average number of sunspots per day (see link below). The highest recent values were between 1933 and 2008 (solar cycles 17-23). SC 24 has slumped to way below those cycles, and most pundits expect SC 25 to do the same.
https://en.wikipedia.org/wiki/List_of_solar_cycles
David, there is something which has been interesting me for a long time. CO2 has always been expressed as a percentage or ppm in a dry atmosphere. However, the Earth does not have a dry atmosphere. From Surface to 70hPa the atmosphere has 57.2% saturation.
I conducted a little experiment with results shown here: https://www.weather-research.com/articles/atmospheric-gas-water-vapour
What do you think the percentage of CO2 would be in such a “wet” atmosphere? I don’t know.
Water vapour is the big variable in the atmosphere, which is why, for consistency, CO2 concentrations in ppm are expressed as a dry gas condition. However the typical range for water vapour concentration is between 0.5 and 3% dependent upon temperature and proximity to the sea, a wet measurement of CO2 would result in a reading 0.5 to 3% lower than the dry condition. The 57.2% saturation figure that you quote is actually a relative humidity value. This is expressed as a percentage of the saturated water vapour content, the maximum amount of water that the atmosphere can hold without condensing at that particular temperature. Figure 6 in the paper shows the saturated water content variation with temperature. Hope this helps.
Thanks for your reply. The link for the full paper, does not work for me. I use Firefox. So haven’t been able to see Fig 6.
The figure 57.2%, as you say is the RH value, as such it is the percentage of water vapour content in the atmosphere, as you say. I suggest that is why there is higher RH in clouds confirmed by upper air radio-sonde data.
The point I was trying to make is, there is a lot more water vapour in the atmosphere of the real world. ..
Thank you David Coe for writing it and thank you Paul for sharing it with us. It’s not too difficult to follow and I believe it because I have read similar papers elsewhere, which draw the same conclusion viz: there will be no catastrophic rise in global temperature due to an increase in CO2 in the atmosphere. But I have never seen or heard any similar article that proves the opposite; yet every day on MSM we are reminded that we are in a state of Climate Emergency and it is essential to stop the rise in CO2. This from eminent scientists too but evidently none of them can prove it.
It is an interesting case of reversed logic that so-called scientists claim a link between CO2 and warming but do not have to prove it conclusively, while those following the null-hypothesis that nothing significant has happened have to some-how prove that. It is actually harder to prove no effect than to claim an unprovable hypothesis and that is the basis of snake-oil salesmen. Normally, the people claiming the change or effect have to prove it.
David Coe: thanks for this. Your point about the relative insignificance of methane is particularly topical given all the propaganda flying around at the moment.
We are told how methane is many times more powerful as a GHG than CO2 but that is based on lab tests in dry conditions. It’s a different story in the real world, as you show.
Never contributed before. David’s review is more persuasive against a climate emergency than almost anything I have read. But I do have a question. What about Venus, which we are frequently told has extreme temperatures due to ‘runaway greenhouse gases’ C02 and H20? I/we need to be able to counter this argument. Is it a solar input issue, volcanic or due the fact the there is no ocean? What stops a cooling effect from radiation to the same extent as the earth?
“What stops…”
There is just so MUCH atmosphere on Venus, and it is almost all carbon dioxide. There is four-hundred thousand times more carbon dioxide in the air than here. The atmospheric pressure at the surface is ninety times greater. And the depth is far greater.*
Earth has always been UTTERLY different from Venus. Our carbon dioxide has almost all been buried as rock. It is silly to try to ‘draw lessons’ from Venus, as if it were an Earth gone slightly wrong.
*If you go up 10 km on Earth you have 90% of the atmosphere below you. To have 90% of the Venus atmosphere below you would require going up fifty kilometers.
This guy thinks he has the answer. I’ve no idea and no knowledge of the science. I can only throw this out for discussion. David Coe’s views would be welcomed.
Mike:
I’m afraid that guy doesn’t really understand basic high school physics.
He confuses the one-time act of compression heating a gas with static pressure, which does not.
For example, as you actively compress air to pump up your car tire, you make the air hot. But when you come back tomorrow after letting the car sit overnight, the air in the tire is no longer hot.
If his analysis were correct, the air in the tire would stay hot indefinitely, which we know is absurd.
Another way of looking at this is that the active compression is a one-time transfer of energy to the gas, whether the tire or the planetary atmosphere. For the gas to stay at elevated temperatures requires an ongoing continuous power source.
The power of compression can be expressed as (right out of high school physics):
Power = Force x Velocity
In the case of static pressure, the velocity is zero, so the power transfer is zero.
Yes, it’s really that simple!
Mike:
It gets even worse! He spends most of his time doing Ideal Gas Law calculations for different bodies. He demonstrates that pressure, temperature, and density agree with the IGL for all of these bodies.
But there is NOTHING in his analysis that explains WHY any of these atmospheres are at these particular states.
Notice carefully that the distance from the sun and so the solar radiation intensity figures NOWHERE in his analysis. That should be a huge red flag that he has no freaking idea what he’s talking about!
Thank you Ed for your understandable reply. Trying to find a way through lots of scientific thinking and data is quite daunting for someone like myself with virtually no scientific background so help like yours is very welcome as is that from David Coe. Fortunately i don’t mind putting my ignorance out there.
Yes, and yes, Venus is far closer to the Sun. Also any atmosphere warms a planet, as any atmosphere receives conducted energy from the surface, and having a residence time of stored conducted energy, while solar energy continues 24 -7, increases the T. The atmosphere on Venus, at the same density as Earth’s atmosphere, is almost the same T. It would quite possibly be warmer except those Venitian GHGs are possibly radiating the heat away.
David Coe:
Your analysis and conclusions are very similar to those of Wijngaarden and Happer, in their paper here:
https://wvanwijngaarden.info.yorku.ca/files/2020/12/WThermal-Radiationf.pdf?x45936
I find their Figure 4 a good way to display the idea. Using the HITRAN data, they show that CO2 does indeed take a significant “bite” out of the upward longwave infrared transmission, but doubling the concentration adds virtually nothing to this effect.
For those who want a shorter presentation with less math, you can look here:
Click to access MethaneClimate_WijnGaardenHapper.pdf
David
I agree with what you say and is the same message uttered by Prof. Will Happer of Princeton Univ but…
Your summary contains partly contradictory statements. Can you address?
I see the comments are getter longer. (Mine too, so apologies). I hope this site does not go the way of some, where the whole thing becomes hopelessly clogged by daily re-enaction of the Battle of Tweedledum and Tweedledee.
I think I need you to be more specific about which statements you believe to be contradictory