Guest post by Rud Istvan
A few days ago, I posted another Lindzen Bode ECS reconciliation. It should have been controversial, stimulating many comments because of the divergence to higher climate models and also to Monckton’s often here posted much lower estimates. It was only mildly so, most about my penetration f/(1-f) versus Bode 1/(1-f) one phrase in one sentence goof, which did not affect the post’s conclusions since it only used Lindzen’s correct curve posted here decade ago.
Recently, Dr. Wentworth posted a ‘mathematical proof ‘ that the GHE must exist, even though misnamed (because real greenhouses retard local convective cooling, while greenhouse gases retard radiative cooling to space). This misnomer is no different than the equivalent ocean acidification misnomer we are also forced to live with in popular discourse. Warmunists long ago picked their definitional terms of debate, and WUWT skeptics are mostly stuck with them. Definitional quibbling may satisfy some, but probably isn’t an effective tactic.
I was very surprised at the number of negative comments at WUWT (now well over 600) to this rigorous post with an obviously verifiable conclusion. They spanned the gamut from epistemological (really a proof, or something else?), to the old Venus/Mars ‘analogies’, to the new ignores convection (true, but convention only moves heat around in the atmosphere; it cannot not make it go away like radiation to space does), to even the very old gravitational density heating canard (ignoring that since Earths atmosphere got densified (aka ‘pumped up’) by gravitational consolidation about 4.5 billions years ago, unlike a newly pressurized bicycle tire it has had a LONG time to cool back down). I chose not to name names; this possible guest post is only a general rebuke.
The surprisingly controversial post’s conclusion is also easily personally verified by simple observation. Tyndall proved in 1859 that both CO2 and H2O were GHG, while N2 and O2 are not. So a personal experiment can be conduced in any desert (mine was a summer day in the Mohave outside Palm Springs during a boring conference). The dry desert heats up a lot from insolation during the day, and cools down a lot at night thanks to desert low specific humidity, so not much GHG except well-mixed CO2, and therefore not much GHE at night. Burrr!
There are only two even semi-rational (but still erroneous) arguments why the CO2 GHE might not exist despite Tyndall’s experimental GHG evidence.
- The CO2 window overlaps the H2O window. Note, this does not say the GHE does not exist; only that CO2 ‘cannot’ be a contributor so IPCC is wrong. This assertion is frequently found on the internet in graphical form, but erroneously portrayed for two reasons (both errors are present in negative WUWT comments). The usual stuff omits radiation intensity; and while some windows do overlap, others don’t. Fine IR scale matters. The actual overlaps/windows plus their radiative intensities were provided in essay Sensitive Uncertainty in ebook Blowing Smoke. The essay’s illustration is reproduced below. Forgive the unfortunate insolation extra zero K typo, which I just caught myself. Absorption is a metric of the degree of a gas GHE effect at some frequency (wavelength), from 0 (none) to 100% (full).
Reality has to do with radiation intensity and window ‘shoulders’.
- GHG are saturated, so can have not have any further effect. This misunderstands saturation, since it depends on the effective radiative level (ERL). As CO2 increases, the ERL rises unconstrained, since CO2 is unaffected by the lapse rate, while H2O is and so decreases. This also reduces their mid troposphere’s overlapping radiative windows. More CO2 raises the ERL. As Callendar’s 1938 curve reproduced below (from Climate Audit) first showed, the GHE never saturates.
Also note that over the region of Callendar’s curve of present interest, the curve is approximately linear, which is why in my comment to UAH’s most recent report, I did not bother to make the log correction correctly suggested in subsequent comments to my back of the envelope implied 1.7C ECS fraction that Roy’s new update nicely implicitly brackets. ‘Good enough for government work’.
To summarize without any math, the GHE exists. It experimentally must, and easily provably does. The GHE issues are how much when (ECS), not if. Any ‘skeptical’ arguments to the contrary are fairly easily rebutted, as done here.
“The surprisingly controversial post’s conclusion is also easily personally verified by simple observation. Tyndall proved in 1859 that both CO2 and H2O were GHG, while N2 and O2 are not. So a personal experiment can be conduced in any desert (mine was a summer day in the Mohave outside Palm Springs during a boring conference). The dry desert heats up a lot from insolation during the day, and cools down a lot at night thanks to desert low specific humidity, so not much GHG except well-mixed CO2, and therefore not much GHE at night. Burrr!”
Two things, or maybe 3.
N2 and O2 don’t radiate any where near as much as CO2 and H2O, and H20 radiate more molecule than CO2. And even in desert there more affect from H20 than CO2. Also in our Ice Age we have a lot deserts on Planet Earth. And having more desert causes Earth to be colder. Or making the Sahara Desert green, would be significant warming effect {probably as much as doubling CO2 levels}. And we should cause the Sahara desert to green. And ancient scientist knew we were in an Ice Age, and knew making warmer was a good plan. Or doubling of CO2 wasn’t bad news, but good news.
“convention only moves heat around in the atmosphere” so if convection moves that heat closer to the top of the atmosphere that does not speed up the energy being radiated to space?
No 2:16pm, convection equally moves that heat closer to the surface so that meaningfully measured there is no global net surface thermo. internal energy gain or loss from updrafts/downdrafts due weather over a climate cycle.
Rud,
Thank you so much for the essay, it is well thought. I would like to point out that you have both of these statements in your essay:
“to the new ignores convection (true, but convention [sic] only moves heat around in the atmosphere; it cannot not make it go away like radiation to space does)”
and later on you have this:
“This misunderstands saturation, since it depends on the effective radiative level (ERL). As CO2 increases, the ERL rises unconstrained, since CO2 is unaffected by the lapse rate, while H2O is and so decreases. This also reduces their mid troposphere’s overlapping radiative windows. More CO2 raises the ERL.”
I haven’t read through all the statements to your essay, and I am sure that many have addressed this, but I thought I’d bring it up just in case. Obviously, these are mutually exclusive statements without additional explanation that convection can transport energy above the ERL, and I know you know that and it doesn’t impact your reasoning on the GHE.
Anyway, enjoyed the read, thanks!
Ah, I now see many have brought it up. Sorry for the redundancy.
I find it amusing, that after being on this site for some 20 years or so, here we are, debating the GHE, and worse, how it relates to climate. And, yet, the same old arguments, people dragging out the same old physics, but, the models are still wrong, as well as their predictions.
When is someone going to try and approach this from a different angle?
Dr. Deanster:
This I have done, with an alternate, falsifiable explanation of the cause of Earth’s changing temperatures, which completely excludes any detectable GHE.
Although frequently posted on WUWT, it is routinely ignored.by everyone–probably too simple for the highly educated minds on this site to.accept. Your thoughts?
http://www.skepticmedpublishers.com/article-in-press-journal-of-earth-science-and-climatic-change/ , .
It’s clear that water vapor acts as a blanket (I try to avoid using the term “greenhouse gases”) to keep the earth warmer at night. Simple observations: last night cloudy min temp 11C, previous night clear skies, min temp 5C.
But I struggle to understand how an increase from 300 to 400ppm CO2 has increased the average global temperature by 1C.
Well an increase from 300 to 400 ppm CO2, might increase global average temperature by 1 C over period of thousands of years.
But there is so many factors in involved over such long periods of time. And any policy addressing something 1000 years in the future, to be polite, would be not practical.
My guess is doubling from 280 to 560 ppm might cause more than .5 C within a century of time.
Or we had 280 to +400 ppm which is + 120 of the 280 to be added to get to 560.
+140 would be half, but the first 1/2 {140 ppm} has more effect than second half of 140 ppm.
So immediate warming from the 120 ppm is already 1/2 of warming one get when it reaches 560 ppm {and not certain it will ever reach 560 ppm}.
And the immediate result, has not [or can not} be measured.
Or IPCC is “very confident” it’s been .2 C or more. And I don’t share such confidence. I might be less confidence in IPCC, as compared to US FBI or US intel services. And US government is talking about UFOs. And WHO committed War crimes.
Instead it might have been as much as .2 C, but we lack enough accuracy in global temperature, to state anything else {IMO}.
Robber,
Correct. It also works in reverse during the day. Clear sky, hotter ground. Extreme examples are arid tropical deserts (little H2O GHG), from more than 70 C to – 18 C or so, or the Moon (no atmosphere to speak of) from 127 C to -180 C. John Tyndall was mentioned in the post, and made the same sorts of observations.
He pointed out that without H2O in the atmosphere, temperatures in England would drop at night to the point that life would become unsustainable. And of course, during the day, temperatures above 60 C are difficult to cope with.
The GHE “blanket” analogy is just stupid. Some desert Bedouins wear heavy black clothing during the day. Peer reviewed research shows that these dark “blankets” are effective at keeping the body cool in the desert sun. Just as cool as white “blankets”, strangely enough. Measurements, not assumptions. Likewise, insulation (“blanket”) is extensively used to keep things cool. Putting a coat on a tailor’s dummy or a corpse won’t make it hotter, but will stop it heating up so much in sunlight.
As do roofs, hats, and parasols. All insulators – “blankets” if you like.
Adding CO2 to a sample of air raises its temperature not at all. Removing CO2 from a sample of air does not affect its temperature, either.
GHE believers have faith, as to the followers of any cult or religion. No relevant facts, and the scientific method is anathema to them.
Such is life.
So I think the debate about GHE is daft it exists. This is a debate about the outcome.
The big difference between H2O and CO2 is the CO2 is distributed virtually perfectly, whereas H2O a condensing GHG and has the ability to transport energy from the surface to about half way up from there the Atmosphere is dry.
The debate is about where energy is absorbed or emitted and given that CO2 is a bit player in the equation but some have claimed that it should result in warm and cold patches in the atmosphere and none have been found is that not correct.
If you think about the difference between CO2 and H2O then that would be the area of research and if that is trivial or zero then it is a problem no more.
You’re still missing the point Dr Istvan, which is the impact of liquid water.
Liquid water is a sink for energy, since on phase change the energy absorbed is locked up until the resulting water vapor condenses again. Which it does in the form of clouds well above most of the CO2 in the air column.
H2O(g) and CO2(g) emission lines are the same as their absorption lines. That energy is continually being re-emitted and re-absorbed all the time…until it gets picked up by a liquid water molecule, whereupon the phase change locks that energy in as latent heat of vaporization.
This occurs wherever there is liquid water available. And can occur so long as relative humidity is less than 100%.
Your first graph of absorption lines shows why the mismatch between H2O(g) and CO2(g) isn’t as important as you might think, because while CO2 is maximum absorption between 10 and 20 microns H2O is still absorbing 50% or more. So any energy absorbed by the CO2 and then re-emitted is available to be absorbed by both gaseous and liquid water (see an absorption spectrum graph for liquid water here). But the latter is the end of the line, until the newly produced water vapor gets to the troposphere and re-emits that energy on condensation. Whereupon it goes to space by a similar process: any photons emitted downwards are captured by GHGs, transferred to water droplets which evaporate, then recondense after diffusing upwards. Whereas photons emitted upwards are gone: out to space, thereby meaning essentially all energy emitted from the clouds during the condensation process is radiated outwards, some directly and some indirectly down-then-up in a second escape attempt.
Now add in the tropical thunderstorm processes, which offer an even faster transportation of latent heat up even to the high troposphere and you can see why empirical ECS is so low.
One implication of this is the empirical GHE from increased CO2, CH4 and etc is confined mainly to deserts where liquid water availability is low. But even there the accumulated greenhouse heat moves eastward fairly rapidly with the weather systems, and then evaporates liquid water to the east a few days later.
The water cycle is not unlike modelling an ethanol distillation column with multiple trays, something which I’ve done. There are sinks at the bottom (the water) and the top (the ethanol vapour). Energy is continually being absorbed and re-emitted in the tray stages. The net result is a clean split of the azeotropic ethanol product from the water, which can’t be done in a single stage.
I do not dispute the greenhouse effect of CO2(g) or H2O(g), just that as a water chemist it’s quite clear to me that the water cycle rather neatly finesses it.
Rud, Bob Wentworth and Willis E all are correct in summarising what IR measurements and some theory show about atmospheric processing of IR by CO2 and water vapour. It’s an internally consistent story that’s had a lot of work done on it.
However many of us simply feel that something ain’t right about the story. This might not sound scientific, but even in science instinct still counts.
Millennia of human years of effort have of course gone into fortifying the CO2 story, and attacking it is like charging WW1 German trenches prepared with 4 lines of defence over years. A lot of us, myself included, have no doubt made ourselves look foolish in the attempt, moving outside core areas of expertise, fighting on the opponent’s prepared ground.
But the real question is not whether the story is true but if the story is relevant. The narrative itself should be left alone; what is omitted is more important.
For instance there is the implicit assumption that IR absorption and emission events account for all the important heat movement in the atmosphere. Two assumptions are questionable. One is that O2 and N2 are inert to IR. they are not. Due to their abundance, even if they interact 100x less than CO2, they will still overwhelm CO2’s effect. The second is that absorption and emission are the be all and end all of CO2’s heat interaction with IR. This notion was flatly contradicted by none other than Albert Einstein. He said that even if a molecule has absorption and emission frequencies, these play a negligible role in heat transfer photon to gas, which is predominantly by collisional momentum transfer:
We must require that the mean kinetic energy which a molecule per degree of freedom acquires in a Plank radiation field of temperature T be
kT / 2
this must be valid regardless of the nature of the molecules and independent of frequencies which the molecules absorb and emit.”
(Note in the above that kinetic energy means heat.)
You’ll have to forgive me, but if Einstein says one thing, and a mob of activists with an overwhelming conflict of interest say the opposite, then I’m just going to stay with Albert if that’s OK with you. And very probably, even if it’s not.
https://ptolemy2.wordpress.com/2020/02/16/albert-einstein-said-no-to-co2-radiative-warming-of-the-atmosphere/
Another assumption is that of “everything else being equal” and the simplicity versus complexity of atmospheric thermodynamics. The adaptive or optimising behaviour of complex systems is ignored, and everything is assumed to be simple and linear. In the real world if a complex dissipative nonlinear system is perturbed, then there will be multiple movements of system players within the phase space aimed at returning the system to the dominant attractor. This is embodied in Ilya Prigogine’s theory of nonlinear thermodynamics of dissipative systems. One key behaviour of these systems is the spontaneous export of entropy by emergent “dissipative structures”. The tropical thunderstorms that eject heat to space when ocean SSTs reach 30C, described by Willis E., are a good example of Prigogine’s dissipative structures.
On the other hand, ignoring all this and assuming “everything else being equal” after CO2 increase, contravenes the important physical law of the principle of least action.
(It also ignores the most important effect of adding to CO2 in air, which is global enhancement of plant 🌱 growth.)
The principle of least action states that the universe will choose the path between two states that minimises the action. This principle is a generalisation of Fermat’s theorem which requires light to take the path between two locations that minimises the travel time.
The principle of least action can be extended to any system evolving between two states. It is the founding assumption behind Noether’ theorem that is required to explain why Einsteinian relativity does not break conservation of energy.
For instance, the CO2 concentration in air increases. How will the atmosphere’s state evolve as a result? Conventionally we are told that the atmosphere’s response to a small increase in this trace gas is to summon up vast quantities of energy to increase the temperature of both atmosphere and ocean. This is an enormous thermodynamic response to this tiny trace gas perturbation, that transgresses the principle of least action.
However, a response by the system rearranging its structure, changing for instance water vapour content or the emission height, or adjustment of convection or even radiative interactions, could lead the system toward a new equilibrium with much less expenditure of energy. And thus fulfil the laws of least action, Noether’s and Fermat’s theorems. Miskolczi’s hypothesis was of this nature – a rearrangement of the emission structure without temperature change.
On the other hand, response to the tiny adjustment of CO2 amount by heating up the whole atmosphere and ocean, is the exact opposite of what one would expect in fulfilment of the principle of least action. It’s the principle of most action, and most (empty) heat and noise.
https://ptolemy2.wordpress.com/2020/02/09/the-principle-of-least-action-calls-into-question-atmosphere-warming-by-co2/
— Two assumptions are questionable. One is that O2 and N2 are inert to IR. they are not. Due to their abundance, even if they interact 100x less than CO2, they will still overwhelm CO2’s effect. The second is that absorption and emission are the be all and end all of CO2’s heat interaction with IR. This notion was flatly contradicted by none other than Albert Einstein. He said that even if a molecule has absorption and emission frequencies, these play a negligible role in heat transfer photon to gas, which is predominantly by collisional momentum transfer:”
I roughly agree with Einstein. But I don’t think O2 and N2 “overwhelm CO2’s effect” but CO2 effect is quite small. But without the mass of O2 and N2, most agree CO2 has a lot less or near zero warming effect.
Or greenhouse effect is the 10 tons of O2 and N2 {and Argon} and when add the tiny amount of CO2 there is some more warming effect. But say up to a round number of 300 ppm there is more “far more” warming from 300 ppm part than from adding another 300 ppm to make 600 ppm.
So if mean the O2 and N2 is a lot more {“still overhelm”} as compared doubling CO2 from 280 to 560 ppm, then perhaps, that is true.
I not sure how warming is from doubling of CO2, if the lower end vs higher end is true. Then it’s more likely, to be true.
I’m frustrated that there is an implicit assumption that other modes of heat movement are being “ignored.” They are NOT.
No. There has been specific, numerical analysis of this issue.
The results show that on a per molecule basis, N₂ and O₂ are, respectively, a factor of 3e-6 and 7e-6 less effective at absorbing/radiating LW radiation than CO₂.
When the actual abundances of gases in the atmosphere are taken into account, the impact of of N₂ and O₂ are 0.6% and 0.4% as large as the impact of CO₂.
So, no, they do not “overwhelm CO2’s effect.”
This is completely wrong. As is the source your link references.
Momentum transfer by the photon to the gas only accounts for one trillionth (one part in 10¹²) of the energy involved in heat transfer from photons to gas.
You and your source are badly misinterpreting Einstein.
His text does not mean that that photons don’t get absorbed by a gas and transfer heat by mechanisms other than the transfer of momentum.
His text only means that the net effect is always a thermal energy distribution within all the energetic modes of the gas. This observation is utterly irrelevant to the conclusion that you seem to be are inferring.
Talking about “everything else being equal” is beyond the scope of what I’m up to addressing in this comment.
However, saying that “everything is assumed to be simple and linear” seems to me to be an inaccurate and unfair characterization.
What you are appear to be ignoring is that N2 and O2 remove the energy from the CO2 molecule far more often by collision than CO2 emits a photon.
Which is why, despite not absorbing LWIR the N2 & O2 are at the same zonal temperature as the CO2 molecule.
They emit in the Microwave range, which is what the Satellites use to measure the temperature.
But they do not remove their energy by LWIR, which in the upper atmosphere only CO2 can do. SO Co2 is the Coolant.
Why do you say I appear to be “ignoring” this? Yes, it is true that collisions happen very often. And, so what?
It’s also true that, while collisions with N₂ and O₂ often remove energy from a CO₂ molecule, collisions also often add energy to a CO₂ molecule, enabling a photon emission.
Yes, all the individual gases within a gas mixture are at the same temperature. There is nothing surprising about this.
In a way, it doesn’t help to think of the constituent gases separately.
Overall, the mixed gas:
How strongly the mixed gas absorbs and emits increases with the concentration of GHGs present in the mix.
Interesting. That partially explains why they would be less effective absorbers/emitters for thermal radiation at temperatures relevant on Earth.
(Satellites also measure LWIR, of course.)
Well, cooling happens via electromagnetic emissions whatever the frequency. It’s just that being able to emit at LWIR wavelengths make for more efficient cooling.
N₂ and O₂ apparently contribute about 0.6% and 0.4% as much cooling as does CO₂. So CO₂ in the upper atmosphere is certainly the main coolant, but not the only one.
Then you must agree that the most efficient Coolant in the atmosphere is CO2.
That’s true in parts of the atmosphere where there isn’t significant water vapor.
Wouldn’t it be necessary for a heating effect of CO2 by LIWR to efficiently transmit energy by collision before emitting a photon?
So downwelling LIWR would be technically wrong, it would be transmission of energy to non-absorbant molecules faster than emitting a photon to space. And what is measured as downwelling LIWR is just the resulting temperature of this imbalance in the speed of two processes.
I suppose that’s true. Because collisions happen on a shorter time scale than photon re-emission, all the received energy thermalizes, contributing to the net temperature of the mixed gas.
No, there’s nothing “wrong” about downwelling LWIR. Perhaps you previously had some interpretation of the mechanics of downwelling LWIR production that you now see to be wrong?
Your thinking here may be a bit “off.”
For one things, photons are emitted in all directions, not just towards space. I don’t know if that matters to your logic.
For another, those non-absorbant molecules often transmit energy to absorbant molecules, which is then emitted as a photon (in any direction).
Not really.
Collisions are frequent, and this gives rise to downwelling LWIR. But, if collisions were rare, that would also give rise to downwelling LWIR. The details of the process would just be slightly different, but in both cases there would be downwelling LWIR.
So, the relative rates of collisions and photon emissions don’t have the sort of significance you seem to be inferring.
Bob
Thanks for your helpful reply.
Experimental data shows the same infrared lamp warming of argon as CO2.
Argon (z=40) has similar molecular number as CO2 (z=44).
Argon (monoatomic) has negligible IR absorption (apparently).
But they both heat the same in an IR field.
Climate change in a shoebox: Right result, wrong physics: American Journal of Physics: Vol 78, No 5 (scitation.org)
Thanks for the reference.
As I read it, this paper indicates that certain table-top “demonstrations” of the GHE don’t necessarily actually demonstrate the GHE. Instead, they demonstrate a change in convection associated with greater gas density.
Do you think that this result somehow disproves the GHE?
* * *
The problem with every experimental “disproof” of the GHE that I’ve ever seen is that people usually don’t bother to check what conventional physics (from which the GHE arises) would actually predict to happen in that situation.
So, for example, many people cite an experimental demonstration that “the Greenplate effect does not exist.” The experimentalist seems delighted to report that he has “disproven” the effect. Yet, he never bothers to check what the predicted effect would be.
I checked to see what would be predicted. It’s expected for the first ten minutes, the effect would only be about 1℃, which is consistent with the results that were reported. If one ran the experiment for an hour, a very large effect (impossible to miss) would have been expected.
Yet, the experimentalist ran the test for only 10 minutes, then erroneously declared he had “disproven” the greenplate effect.
It’s important to check what a theory actually predicts, before declaring that one has in some way falsified it.
* * *
In the table-top experiment, I am confident that looking at the predictions of conventional physics would show that, despite the IR absorption of CO₂, that IR absorption would be expected to have a rather small impact on temperature for that experimental configuration.
A table-top setup is going to contain much less CO₂ per unit area than does the Earth’s atmosphere. Despite CO₂ being less concentrated in the Earth’s atmosphere, the atmosphere is many kilometers deep, whereas a table-top demo is likely to be just half a meter deep.
The effects of LWIR absorption by CO₂ would be expected to be much larger in the atmosphere than in that table-top “demonstration.”
The paper you cite does seem to (likely) invalidate the demo as a correct demonstration of the GHE. But, it doesn’t in any way disprove the GHE.
One of these days, I guess I’ll have to work through what size GHE would be theoretically expected in a table-top experiment. (It’s possible that the experiment does demonstrate the GHE, but one has to look at finer details than what is usually taken as indicative of the GHE.)
Yes the authors did point to convection. It was a short article excerpt only and the full experimental details were missing.
The point is though that if it really was true that most of air – oxygen and nitrogen – have almost zero interaction with IR while CO2 interacts strongly, this would be simple to demonstrate and experiments with heating of CO2 or other non IR active gasses would show an overwhelming and unmistakable difference. Instead it’s like looking for a needle in a haystack.
One is that O2 and N2 are inert to IR. they are not. Due to their abundance, even if they interact 100x less than CO2, they will still overwhelm CO2’s effect.
No. There has been specific, numerical analysis of this issue.
The results show that on a per molecule basis, N₂ and O₂ are, respectively, a factor of 3e-6 and 7e-6 less effective at absorbing/radiating LW radiation than CO₂.
“Specific numerical analysis of this issue??” What’s wrong with a simple experiment to conclusively prove that CO2 absorbs heat from IR and that O2 and N2 don’t. Show us.
But no-one can. Experiments trying to show higher heat absorption by CO2 read like cold fusion experiments. Endless argument over tiny observed discrepancies and experimental details. Not convincing at all.
So instead a retreat to theory? “Numerical analysis”?? LOL 😂 The optics are not good.
The GHE does exist. Those arguing it does not are wasting our time. There are more important things to do than nanny the unconvinced. You all should branch off and form your own website. Then people can visit that and argue with as to why it does exist. The same things would happen. Just elsewhere. Likewise the Democrat Party should say you CRT people are bleeping crazy and kick them out of their party. We know if they did, they’d have an easier time of things.
Ragnaar,
You wrote –
“The GHE does exist.” And so do bananas. The difference is that I can describe a banana, tell you where one may be observed and measured, and so on.
Go on – describe this “GHE”, tell me where I might observe and measure it . . .!
Only joking of course! You can’t describe the GHE in any sensible way. At least people can describe the mythical unicorn more or less consistently – looks like a horse with a single horn growing out of its forehead, gentle nature, that sort of thing.
Try describing the GHE in way that makes physical sense.
What’s the matter? Cat got your tongue?
GHE effect is when a surface is heated and it heats the air {usually} above, it’s convection heat. It also occur when surface evaporate into the atmosphere.
But I know you more interested in radiant aspects, because that all the cargo cult people talk about. There is idea that when gas molecule absorbs radiant energy, it transfer {translate??} this energy into kinetic energy {increase the average velocity of the atmospheric gases] this theory is difficult or complicated by a number unknown “variables”. And there other idea {like Roy Spencer explains it] as acting as insulation. And I also believe there other theories “of how it works”.
Anyhow, I believe there is greenhouse effect on Venus, and involves the high elevation clouds. And also there effect of Ozone, which the cargo cult likes to pretend is a greenhouse gas. {though doesn’t fit their definition of greenhouse gases}.
There is idea that when gas molecule absorbs radiant energy, it transfer {translate??} this energy into kinetic energy {increase the average velocity of the atmospheric gases] this theory is difficult or complicated by a number unknown “variables”.
————————
How does a warm object warm a cooler object? Radiation. There is an energy transfer. And energy can be thought of as the velocity of a gas. Very cold gases don’t vibrate, or whatever term you want use, much. Warm gases do vibrate a lot. Liquid water also does this. It slows down and speed up. I don’t know what is unknown about this? It’s H.S. stuff.
“And energy can be thought of as the velocity of a gas.”
The energy of gas is the average velocity {according to theory
of ideal gas laws]. A gas molecule which doesn’t have any kinetic theory in period of a nano second time can increase the average velocity.
Or it’s average velocity within a volume of space- not just velocity- it’s an relationship with all the gas molecules within volume of space.
Rud Istvan says:
“There are only two even semi-rational (but still erroneous) arguments why the CO2 GHE might not exist despite Tyndall’s experimental GHG evidence.”
Rud, You seem very confident, even dismissive, with this statement. Please open your mind.
Nobody is saying that CO2 does not emit electromagnetic radiation (‘photons’), or that some of these emissions go downwards to the earth’s surface. The issue is do those emissions increase the temperature of what they impact?
Do you believe that all EM emissions increase the temperature of what they impact?
If you say yes, then you are wrong.
Three simple experiments, that can be done by any WUWT reader, prove that not all emissions increase the temperature of objects they impact. Here they are:
1) Place a 100 degree object on a table. Then, place a second 100 degree object next to it. Does the temperature of the first object immediately go up? The answer is no, its temperature does not increase. How can this be true given the arrival of all those new photons? The answer is that not all photons increase the temperature of the objects they impact. Some do, some don’t.
2) Now, conduct the second experiment. Place a 100 degree object on a table as before but this time place a second object next to it that has any temperature greater than 100 degrees. What immediately happens to the temperature of the first object? It goes up!!
3) Now, conduct the third experiment. Place a 100 degree object on a table as before but this time, place a second object next to it that has any temperature less than 100 degrees. What happens to the temperature of the first object? Nothing!!
That is experimental proof that not all emitted photons increase the temperature of what they hit. Notice I proved that without using any Stefan Boltzmann equations!
Those three simple experiments prove that emissions only increase the temperature of what they hit if they originate from an object that has a greater temperature than the object they hit.
Now, since I have proven that not all emissions increase the temperature of what they hit, let’s go back to CO2 emissions. My hypothesis is that, because the emissions from atmospheric CO2 come from the colder atmosphere, they cannot raise the temperature of the warmer earth’s surface.
Rud, this request is to you personally. Please explain how some photons increase temperature and some don’t. You may use SB equations if you want, though I don’t think that is possible. If you cannot explain it, will you admit that it is possible that cold CO2 emissions cannot warm an already warmer earth’s surface?
Best regards
Bernard,
I, for one, agree with you.
Ice can emit 300 W/m2, and the GHE true believers fall about the place trying to avoid the fact that no amount of energy from ice can make even an infinitesimal amount of liquid water hotter.
You are right, and no amount of blathering about energy levels, rotational, vibrational and translational energy do any more than to expose the ignorance of the blatherer. Unless supported by additional information which demonstrates knowledge, rather than assertion based on a cursory look at Wikipedia!
Why doesn’t my 8 feet of average depth lake in MN freeze all the way to the bottom each Winter. Because the ice makes the water warmer. If exposed to air, that water would freeze. The ice gets photon from below and throws them back. Jesus.
You did not prove anything, you merely asserted it, and if you actually did that experiment, you would find out where you went wrong.
To do correct put object in hot or boiling water. Cook for an hour {or longer if more massive- like boiling potatoes- big potatoes take longer to cook}.
Nicholas,
Are you really trying to counter predictions apparently based on physics, with completely unsupported assertions based on nothing at all?
That might not be too convincing. Maybe you could try what has been suggested, and then cut Bernard off at the knees, so to speak, by reporting facts that show he is wrong.
I believe you have no clue about physics, but facts overcome faith. Have you got any to present?
Yes, this one: You may be the single most obnoxious jackass on the entire internet.
You didn’t do the experiments, did you?
I did and you are right, especially if you provide air movement to prevent them warming air between them, then it does not even slow down their cooling rate.
As I said above the Heat Transfer equations also show no transfer of heat.
I have done the experiment and he is correct.
The Heat Transfer equations prove that if 2 objects of the same temperature are placed in close proximity zero heat or heat flux is transferred. So how can all photons cause warming when the Heat transfer equations show that they do not?
What does happen is that the air between the objects on the table gets hotter and thus very slightly slows down the cooling rate.
However if you place a fan blowing air throught the gap as I did they cool at the same rate as when only one for them is there.
Yes.
The greenhouse effect does not make anything hotter.
That highest air temperature ever recorded was over 100 years ago,
doesn’t change my idea of what global warming is, instead more proof of global warming.
Global warming is about increasing average global surface air temperature.
If measuring the temperature of a sidewalk {which has nothing to do with global warming]
and the air is warmer, the sidewalk will convect less heat to the air {it will cool less to the air}
and because sidewalk is losing less heat to atmosphere, it can get hotter.
Or if want find a sidewalk which is close to 70 C, you need a dry sidewalk, you need the sun near zenith {somewhere near} and you need air about 40 C [104 F} or more.
And without the warmer air, a sidewalk will reach about 60 C. If stop all convection heat loss
a sidewalk might reach 80 C] but as said warmer air or less difference of temperature reduces convectional heat transfer to air.
And global warming instead of extreme temperature difference will cause a more uniform night and day {and summer and winter temperature}. And mostly about polar increases in average temperature {which doesn’t mean it doesn’t snow- Canada average temperature is
-3 C. And US has winter temperature of colder than -50 C {or as they say, too cold to snow}.
True serious global warming will cause the Sahara desert to green.
You are making a “straw man” argument, misrepresenting others’ beliefs then disproving a theory you’ve made up.
The key to the whole global warming debate is whether people accept that some emitted photons increase the temperature of what the hit and some don’t. If you accept that premise, you have to accept that ‘cold CO2’ emissions won’t warm the warmer earth’s surface. That’s not a straw man argument, it’s an acid test.
That is a mis-framed premise.
Radiative theory doesn’t talk about “all photons warming what they hit.”
That sort of technically true, in a way, but also not. If you think about the issue that way, it’s likely to lead you to incorrect conclusions about what radiative heat transfer theory predicts.
What radiative theory says is that “all photons transfer energy to what they are absorbed by, and the likelihood of being absorbed doesn’t depend (much) on the temperature of the object. Temperature is determined by the net balance of energy flowing into and out of an object.”
Your examples fail to account for the “net balance of energy flowing into and out of an object.”
You are presenting radiative theory as if it was about “photons increasing the temperature of an object.” It’s not. It’s about photons adding energy which will raise temperature if and only if the net balance of energy flows calls for the temperature to rise.
You are not relating to an accurate representation of the theory you are trying to assess.
Bob,
Are you then saying you don’t believe that all EM emissions increase the temperature of what they impact?
Or do you believe that all EM emissions increase the temperature of what they impact?
Just a question. Either one answer or the other applies. No “straw man” involved, unless you are building one to avoid being pinned down to something specific.
I believe that all EM radiation absorbed by an object adds to the internal energy of that object. EM emitted by an object decrease the internal energy of an object.
The temperature of an object is a measure of its internal energy.
So, in a sense, yes, all EM radiation absorbed by an object increases the temperature of the object—except insofar as other factors lead to cooling which offsets this temperature increase.
Temperature is never a function of just one radiation flow. It is always the net result of all radiation flows.
I see people consistently coming up with ridiculous examples that use the “absorption leads to heating” part of the statement while entirely ignoring the issue of “offsetting cooling.”
It’s the arguments that ignore offsetting cooling which are the “straw man” arguments.
(These sort of arguments sometimes also ignore “view factor“, which is a consideration in how objects at two different temperatures affect one another.)
Verbal arguments about temperatures of objects very easily go wrong. It’s useful to actually study the theory of radiant heat transfer.
You can only “debunk” the predictions of a theory if you know what the predictions of a theory are.
Bob,
I agree that temperatures are the result of flows of energy. Having said that, all bodies have a precise temperature at a specific moment in time. The experiment I described was to measure the immediate change in that precise temperature of a body when a second body was placed next to it with the same or a different temperature. The results of the experiment clearly show that sometimes the temperature of the first object immediately increases when a second object is placed next to it and sometimes it doesn’t. If you vary the temperatures of the second body, you find that the first body only increases in temperature when the second body has a higher temperature. That means that sometimes emissions raise temperature and sometimes they don’t.
This is a profound conclusion if you consider the earth’s surface to be the first body and cooler atmospheric CO2 to be the second body.
Bernard,
The problem with your experiments is that you are unrealistically looking at situations with only two objects.
Looking at situations with only two objects leads to false beliefs about how things work in general.
Situations with 3 or 4 objects would be far more relevant.
Consider the following two experiments:
Experiment Alpha:
Line up 3 objects: A, B, and D.
These objects are flat plates and the distance between them is much less than the size of the plates. The plates are inside a well-insulated container to eliminate outside influences.
A is at 300 K (and this temperature is kept fixed by a thermostat)
D is at 3 K (and this temperature is kept fixed by a thermostat)
B is between objects A and C, and is allowed to come to an equilibrium temperature.
I claim the equilibrium temperature of B will be 252 K.
Experiment Beta:
In the previous experiment, add another object C between objects B and D. (Object C completely blocks the path between objects B and D.)
Object C is at 228 K.
The temperature of object B is once again allowed to come to an equilibrium temperature.
I claim the equilibrium temperature of B will be 271 K.
Discussion:
In experiment Alpha, the temperature of B was 252 K.
Then, in experiment Beta, we added object C at temperature 228 K, and this led to object B having a temperature of 271 K.
Note that introducing an object colder than B (since 228 K < 252 K) led to the temperature of object B increasing.
This is because object B “seeing” object C at 228 K, instead of object D at 3 K, allowed object B to come to a higher equilibrium temperature.
This is what people mean when they say it is possible for a cold object (C) to make a warmer object (B) even warmer.
(In case you missed the connection, A is analogous to the Sun, B is analogous to the surface, C is analogous to the atmosphere, and D is analogous to space.)
Does this make any sense to you?
Bob,
I don’t know whether your experiments result in the temperatures you say. For the sake of argument, I happily accept that your calculations are correct. However, you have introduced the concept of equilibrium plus you have introduced objects with internal heat sources controlled by thermostats. That massively complicates what I see as a very simple experimental result. Namely that sometimes emissions cause the temperature of an object to immediately increase and sometimes they don’t. A simple, real world experiment demonstrates that. I would hazard a guess that the majority of WUWT readers don’t know that this is true.
In the real world, nothing is ever in equilibrium. Everything moves towards equilibrium but it is never achieved. I think it is more helpful to consider the universe to be made up of countless objects, each with an individual temperature at any one moment in time. Heat always flows ‘down-hill’ from warmer objects to cooler objects. This energy gradient includes every object in the universe. Now, go back to the simple experiment above … no cooler object can cause an immediate increase in temperature of a warmer object. In fact, only warmer objects can cause an immediate increase in the temperature of another object. I see no need to complicate matters by introducing internal heat sources, thermostats, equilibrium etc when none of those exist in the real world … everything is just objects with a temperature. By the way, everything is cooling down … unless it is temporarily warmed by a warmer object.
Best regards
My experiments make explicit something that is implicit in your experiments, which you are not noticing.
Your experiments all take place in a context where there is a certain ambient temperature. You would experience different results if the ambient temperature was different.
The extra objects (and thermostats) I add model that ambient context which you are including only implicitly.
As far as my introducing equilibrium, all the statements that you are disputing are statements about equilibrium. Some things are simpler when one talks about equilibrium than when one looks at transient conditions. However, I might be able to make my point without focusing on equilibrium…
You are failing to take the environment, the ambient conditions, into account.
I believe you are implicitly assuming the environment is at the same temperature as your object of interest.
What happens if it’s not?
Suppose that you (at 37℃) are in a warm room, and you go stand next to a stone wall that is at 20℃. You’ll feel cooler, right?
But, suppose the air in the room is cold, 0℃. Now, when you go stand next to that stone wall at 20℃, I maintain that you will actually feel slightly warmer.
The temperature impact of an object B on object A is not determined by the temperature of B relative to A. It is determined by the temperature of object B relative to the temperature of whatever object C that B blocks the view of.
If you put a 20℃ wall between you and a fire, you will feel cooler. If you put a 20℃ wall between you and an enormous block of ice, you will feel warmer.
You are focusing on the wrong temperature comparison.
Bob,
‘Ambient’ is really countless other objects with different temperatures. The only assumption I made about the ‘ambient’ temperature was that it was not warmer than the first object. If the ambient temperature was already higher than the first object then the first object’s temperature would already be increasing. Adding a new, warmer object would therefore accelerate that warming.
It’s easier and clearer to keep it simple. Assume that the first object is cooling. Then introduce the second object. The only way you can get an immediate rise in the first object’s temperature is if the second object is warmer.
So, as you requested, I have added assumptions about ambient temperature and the experiment’s results still hold true.
Best regards
That’s true, but isn’t “simpler” if that’s your goal.
I’m quite certain this is NOT the only assuming you are making about the ‘ambient’ temperature .
Please consider the case where the environment includes a very cold object, and the new object you introduce (which may be cooler or warmer than the first object, but is certainly warmer than the very cold object) is placed between the first object and the very cold object.
If you are making this assumption, then you are specifically refusing to consider an example would me most analogous to what people are talking about when they talk about the GHE.
That’s “clearer and simpler” only if you deliberately want to not understand what people mean when they talk about the GHE.
Bob,
You keep trying to introduce other people into our discussion and more complicated assumptions into the experiments. It’s not my job to try and understand ‘what people mean when they talk about the GHE’. My argument would be that if they don’t agree that some emissions raise temperature and some don’t, then ‘they’ would be wrong. It is a reproducible experiment with 100% guaranteed results. I would urge you to do the experiments and then try to explain the results. I would be very interested if you reach a different conclusion to mine … that some emissions increase temperature and some don’t.
Thanks for the discourse though. It has been an interesting discussion.
Best regards
I agree with the results of the experiments you offered, but I’m not particularly comfortable with the way you frame your conclusions about the meaning of those results.
* * *
If you want to apply your interpretation that “some emissions increase temperature and some don’t” to only this one situation with two isolated objects, then I find the conclusion trivial and uninteresting (and I am unsure why we are even talking about it).
But, if you want to apply that conclusion to any more complex situations, then I think that your way of framing your conclusions is almost certain to cause trouble and lead to false conclusions about those more complex situations.
That’s why I have repeatedly asked about more complex situations.
I guess I’ve assumed that you will want to apply your conclusions to more complicated situations. If not, I don’t really get why the experiments were of interest to you.
Best regards
I’ve just realized that your experiments omit the influence of the surrounding environment, and that that environment affects the results.
The only reason a cold object cools the object it is placed next to is because it is cooler than the environment.
If the cold object were warmer than the environment, and blocked the view of the environment, then adding the cold object would allow the other object to warm, or at last to cool less rapidly.
You’re coming to false conclusions as a result of not considering the larger context.
(My other comment with detailed experiments quantifies this.)
This is not a fully specified experiment but that’s understandable in a casual discussion. Let me make some assumptions about the unspecified conditions and you can correct me if you meant something else and it affects the results.
When you talk about putting an object on a table, and making the assumption we are not doing this in a vacuum, we are doing this in an ordinary room at typical room temperatures with the air in the table are both at typical room temperatures (less than 100 degrees)
You start by placing “a 100 degree object on a table”
In the absence of any unspecified flows of heat to the object, and in a room less than 100°, the object will immediately begin cooling.
You then state:
> “1) Place a 100 degree object on a table. Then, place a second 100 degree object next to it. Does the temperature of the first object immediately go up?”
I agree with you, that the temperature of the first object will not go up. However, it is true that the rate of cooling of the first object will slow down.
Next:
> “2) Now, conduct the second experiment. Place a 100 degree object on a table as before but this time place a second object next to it that has any temperature greater than 100 degrees. What immediately happens to the temperature of the first object? It goes up!!”
Not necessarily. Both objects will begin to cool, being in an environment surrounded by a cooler gas. There will be some net heat transfer from the second object to the first, but whether the first object heats up depends on whether the net heat transfer from the second object to the first is a higher magnitude than the rate of cooling in the absence of the second object.
Next:
> “3) Now, conduct the third experiment. Place a 100 degree object on a table as before but this time, place a second object next to it that has any temperature less than 100 degrees. What happens to the temperature of the first object? Nothing!!”
Not quite. Both objects will begin cooling immediately after being placed on the table. If the temperature of the second object is less than the first part higher than the ambient room temperature, the rate of cooling of the first object will slow down. The object won’t heat up but it will cool off slower than in the absence of the second object.
Stephen,
Thanks for the response. Yes, your increased detail of assumptions are all in line with my assumptions. Plus, you also introduce the extra element that all the objects are cooling to some degree or other. My intent was to measure the ‘immediate’ temperature change when the second object was placed next to the first object, rather than measure what happened to the rate of cooling. That is because the temperature increase from adding a warmer object is immediate, whereas adding an object at the same or lower temperature had no immediate temperature effect on the first object. Hence my statement that some emissions increase temperature and some don’t is still valid. I wasn’t trying to avoid talking about cooling, it’s just that it wasn’t necessary to make my point.
Best regards
Stephen, I have conducted all three experiments and the rate of change in cooling of the first higher temperature object is virtually immeasurable with another high temp object or a slightly cooler object.
Especially if you provide a small amount of air movement between them.
Because the air between does warm up and slow the cooling.
But is not detectable at all when a cold object is placed next to it and the cooling is very much faster
You are concluding that a photon bounces off another object without doing anything or that that photon disappears without doing anything. That’s just dumb. If you account for everything, the mofo went somewhere. We don’t allow bleep to just disappear or objects to have anti photon magic protection. I want the theory that explains disappearing photons. Maybe add a blackhole to experiment.
Ragnaar,
I have to admit that I have no idea why some photons increase temperature and some don’t. However, it is definitely a fact that can easily be demonstrated. I suspect it is something to do with the frequency of the emissions and that shorter wavelength emissions have more energy than longer wavelengths, but I don’t know what the mechanism is. I agree with you though that it is probably not due to magic … or a black hole!
Best regards
Actually, it’s due to the magic of mathematics and the way that radiant heat transfer works.
It turns out that photons are absorbed independent of relative temperatures, without needing to be “disappeared”, and the math always makes it “just work out.”
Bob,
The photons could be absorbed, reflected, pass right through or even trigger the immediate release of other photons – I have no idea.
Although I don’t know what the mechanism is, the results of the experiment are simple and irrefutable. Sometimes the photons increase temperature and sometimes they don’t. When the temperature of the second object is higher, they do. When the temperature of the second object is lower, they don’t.
Best regards
Conventional thermodynamics has a standard explanation that involves none of those things. It involves the photon always being absorbed and transferring its energy. And, it accurately predicts what happens, including in the sort of situations you are examining.
It’s not irrefutable. I refute it. I reject the idea that your statement is a well-formulated and meaningful premise. It seems to depend on a false mental model of how things work.
There are photons and there are temperature rises, but you are inappropriately under-specifying the system in a way that makes your statement imprecise and potentially misleading.
You’re talking about what the “photons do to temperature” when temperature is an emergent property of more factors in the system than just the photons you are focused on.
This is true only in the context of an isolated system with only two objects in it. That is a critical qualifier.
Forgetting that qualifier will lead you to make false inferences about what is likely to happen in more complex systems.
There is also this quote
“The energy transferred as heat in a given process changes the internal energy of each object with equal and opposite quantities. The sign of the heat amount indicates the direction of the transfer. For example, in a transmission from system A to system B, the negative sign indicates energy flowing in the reverse direction.”
Which is precisely what you get when you place the cold object on the left hand side of the heat transfer equation instead of the hot object.
How about writing clearly AC:
“The thermodynamic internal (thermal) energy transferred in a given process changes the internal energy of each object with equal and opposite quantities.”
“The sign of the thermal energy amount indicates the direction of the transfer.”
“Which is precisely what you get when you place the cold object on the left hand side of the thermal energy transfer equation instead of the hot object.”
Trick, not my Statement, it is from a Science source on the web.
Yes, you are offering a valid description of what happens between two objects in a thermally isolated system.
What I worry about is the way that people often analyze simple two-object systems like this and then make incorrect false inferences about what “must” happen in more complicated systems.
I’m content with what you’re saying as long as you are not going to now jump to saying, “therefore adding an atmosphere which is cooler than the surface can’t increase the temperature of the surface.”
That would be a false inference, trying to transfer an analysis of a situation with only two thermodynamics objects to making inferences about a system with at least four thermodynamic elements.
Some simple questions from a non science educated…..
-Claim…. Adding more co2 ”traps” more energy leaving the surface – (it increases the density of the GHGs and reduces the ”window” or ”free passage” to space = increases back radiation) That’s what everyone is saying thereby slowing cooling. Right, got it.
-But if you increase the concentration of an energy trapping gas in a non-contained space, the density cannot remain the same. The molecules move further apart – This MUST occur given the gas law right?
-So now, how does the ”window” to space remain reduced?
-After reading this passage from Clyde on the other thread, I think it bares repeating for further comment….
”The other side of that coin is that an increasing proportion of polyatomic (radiative) molecules will more readily emit energy in the upper atmosphere (and their higher specific heat capacity will more efficiently transit energy surface-to-upper-atmosphere). This has the effect of attempting to make the lapse rate more vertical by transiting more energy to the upper atmosphere and thus make upper atmosphere temperature closer to surface temperature… except those same molecules radiatively cool the upper atmosphere faster than they can convectively warm it.
That’s partly why the upper atmosphere has experienced a long-term and dramatic cooling (even as the troposphere experienced no statistically-significant temperature trend for ~2 decades), and since the lapse rate is ‘anchored’ at TOA (that altitude at which the atmosphere effectively becomes transparent to any given wavelength of radiation), and since the heat transfer equation must (eventually) balance, the surface must cool with an increasing atmospheric CO2 concentration.”
-Sorry to all the believers, but proclaiming that the GHGE is a done deal is not cutting it with me as yet. (but of course that could be a failure of understanding on my part)
-For those of us not too mathematically inclined, text as above rather than equations has more resonance.
-Thanks to all for an interesting read..
If the atmosphere gets warmer, it will expand, and the “height” of the atmosphere will increase.
However, while the density at any one place will increase, the total number of GHG molecules above you, or the density per unit area (as opposed to volume) will remain unchanged. There will be just as many GHG molecules between the surface and space.
* * *
As to Clyde’s argument… Verbal arguments about the behavior of complicated systems are highly unreliable. One really needs to work through the math and see what it tells you.
Here’s another verbal argument, which like Clyde’s may be unreliable, but it leads to a different conclusion:
For what it’s worth.
Hot, high, and humid. Pilots know this. As the air gets thinner, what happens to the GHE? I mean really, really thin like on Mars? But in order to power that thin atmosphere, you need lots of energy, or else it’s not thin. The fact that the atmosphere exands is a feedback. And it’s not a postive one. Runaway global melting feedback is not like on Mars. A thin atmosphere is worthless. You can’t lift a plane or moderate temperatures.
Say the gases expands in one direction, towards the TOA. The gases have more volume. The trips between molucules become longer. It’s really complicated. I think that have these things called line by line transfer models.
Given that the speed of light is so fast, the time it takes light to travel between molecules is entirely negligible, as are changes in that trip time.
Yes, there are line transfer models. And, I don’t think that increasing distances between molecules has much effect on their results when one considers the atmosphere as a whole. The total number of molecules encountered matters much more than the distance between them.
” There will be just as many GHG molecules between the surface and space.”
Not to any given photon there won’t. If they are further apart they are less likely to intercept the photon.
I don’t agree with your analysis. And this is a type of analysis that physicists are used to doing.
It’s appropriate to speak in terms of molecules per square meter in a vertical column extending from the surface out to space.
That cannot change, no matter how much the atmosphere might heat or cool and expand or contract. That dimensions of the atmosphere can change only in the vertical direction, not in the horizontal direction.
So, if you’re looking upward, you will always see the same number of molecules per square meter, unless mass is added to or subtracted from the atmosphere as a whole.
And, it is that density on a per square meter basis that determines the probability of a photon being intercepted by a molecule on its way from the surface to space.
Assumes that increasing atmospheric concentration of CO2 will drastically increase effective emission height, thus shifting the lapse rate (which is ‘anchored’ at TOA, that altitude at which the atmosphere effectively becomes transparent to any given wavelength of radiation) such that the extra height results in higher temperature at the surface due to the lapse rate.
In reality, the change in effective emission height isn’t much.
Also discounts the eventuality where that effective emission height surmounts the tropopause, resulting in higher radiant exitance with increasing effective emission height, resulting in more cooling with increasing atmospheric CO2 concentration. Given that the effective emission height for CO2 is ~15-20 km now (based upon Brightness Temperature of CO2 emission), and given that the tropopause ranges from 17 km (equator) to 9 km (poles), I surmise that if we haven’t already reached that point, we’re very close to it.
The whole “Effective Radiation Level” narrative is a bit oversimplified, in that the “level at which the atmosphere becomes transparent” is strongly a function of wavelength, so there is not really any single altitude involved.
The ERL is an emergent, after-the-fact nominal radiation level that averages out many different radiative effects and doesn’t really correspond to “the” place where physically interesting things are happening.
Even CO₂ doesn’t remotely have a single “effective emission height.” The optical depth at the center of the 15 micron band and in the wings is vastly different, meaning that the “effective emission height” will also be very different, with the height being much lower in the wings of the emission lines than at the center.
I wonder, too, how much the “effective emission height” will change with respect to different parts of the emission band. I have a sense that the change will likely be larger in the wings that at the center, but I haven’t done any math to confirm that idea. (I think it’s consistent, though, with the idea that the absorptive effects are nonlinear with concentration. The increase may be more linear in the wings, and more nonlinear at the center.)
If the “effective emission height” is near the tropopause at the center, it would still be much lower in the wings.
And, if the central CO₂ “effective emission height” shifts into the current tropopause, I don’t think we can take for granted that the temperature profile at those altitudes couldn’t shift.
* * *
The ERL narrative is a nice intuitive story, but in practice I’d want to see results of modeling rather than relying heavily on intuition about what “should” happen.
Bob Wentworth wrote:
“The whole “Effective Radiation Level” narrative is a bit oversimplified, in that the “level at which the atmosphere becomes transparent” is strongly a function of wavelength, so there is not really any single altitude involved.”
True. In fact, TOA (that altitude at which the atmosphere effectively becomes transparent to any given wavelength of radiation) for some wavelengths is very near the surface.
That’s sort of the reason that an increasing atmospheric CO2 concentration doesn’t have much effect upon the overall altitude at which the lapse rate begins having an effect upon surface temperature… because it only absorbs in relatively narrow spectral bands, so its contribution to the overall Effective Emission Height for all wavelengths is small.
The absorption shoulders of CO2 have a lower cross-section (the shoulders are off-resonance absorption due to collisional and Doppler broadening, which is why they absorb less than the center), so I would surmise that they would have less effect upon CO2’s Effective Emission Height than the center, which implies an even smaller effect upon the overall Effective Emission Height for all wavelengths.
Ok. As someone way out of my pay grade I’ll consider myself rebuked.
For the record I point out two things in mitigation:
And I remain uncertain of what Rud Ivstan defines the GHE to be. That would help me to decide whether I agree with his statement that “To summarize without any math, the GHE exists.”
And if it is not too much to ask may I enquire what Bob Wentworth proved? Is his definition of GHE the same as Rud Ivstan’s? As precisely as possible please because I think Bob Wentworth argued around in a circle and proved precisely zilch.
Here is something cut and pasted from one of John Tyndall’s books –
“The upper parts of the grass radiate their heat into regions of empty
space, which, consequently, send no heat back in return ; . . .”
Grass on the surface radiates directly to space!
As does everything else on the surface, with very, very, small amounts of radiation, at specific frequencies, intercepted by gases, aerosols, and suspended matter in the atmosphere, and almost instantaneously re-emitted, generally at lesser energies and hence lesser perceived temperatures.
No support for a GHE by Tyndall, just by readers with small attention spans, and poor compression of the written word.
–Here is something cut and pasted from one of John Tyndall’s books –
“The upper parts of the grass radiate their heat into regions of empty
space, which, consequently, send no heat back in return ; . . .”
Grass on the surface radiates directly to space!–
John not living in the Space Age, probably didn’t think space meant 100 km up.
But I am wildly guessing, empty space means away from most of the rest of the grass.
gbaikie,
No. You can read it yourself if you wish, but he meant space – the nominal vacuum which surrounds the Earth, the Moon, the Sun, and all the rest.
19th century Irish dude who thought of about space, too.
The science is very clear there is a GHG effect and that almost all of it is from H2O and CO2, and that the net GHG warming effect is estimated to be between 26K~33K.
Logically, since H20 absorbs almost the entire LWIR spectrum and has an atmospheric concentration of around 30,000ppm, and CO2 primarily absorbs 15 micron LWIR and is at a paltry 415ppm atmospheric concentration, the vast majority of total GHG warming is from H20.
The CAGW hypothesis estimates CO2’s ECS is around 3C, which is logically absurd because there have already been 9.5 doublings of CO2 (1ppm~415ppm) so at ECS 3.0C, it would mean CO2 has generated 28.5C of total GHG warming (9.5 x 3C) and H2O’s GHG warming would be between -2.5C and 4.5C (26C-28.5C or 33C-28.5C), which makes absolutely no sense.
CO2’s ECS is estimated to be: 5.35watts/M^2*ln(560ppm/280ppm)*(.31 Stephan-Boltzmann constant)=1.2C gross GHG warming – negative feedback effects.
At maximum ECS=1.2C with no negative feedbacks, that would mean CO2 GHG warming has generated 11.4C of warming (1.2C x 9.5) and H20 has contributed 14.6C~21.6C (26C-11.4 or 33C-11.4C), which still seems CO2 net forcing is too high.
I think the negative cloud feedback is very strong at around 50% making CO2’s ECS 0.6C (1.2C x .5), which would mean CO2’s net GHG effect to date would 5.7C (0.6C x 9.5) and H20’s total warming to date would be 20.3C~27.3C (26C-5.7C or 33C-5.7C), which logically seems about right.
Regardless, the CAGW hypothesis is a complete scam as it assumes a runaway positive feedback loop, when the net cloud feedback effect is negative…
–The CAGW hypothesis estimates CO2’s ECS is around 3C, which is logically absurd because there have already been 9.5 doublings of CO2 (1ppm~415ppm) so at ECS 3.0C, it would mean CO2 has generated 28.5C of total GHG warming (9.5 x 3C) and H2O’s GHG warming would be between -2.5C and 4.5C (26C-28.5C or 33C-28.5C), which makes absolutely no sense.–
ECS [equilibrium climate sensitivity ] is best to understand as poorly defined religious expression. But if you prefer, you can call it a wonk term.
{{ The noun wonk is an informal way of referring to an overly studious person. Wonk is as derogatory as words like “dweeb” or “geek,” and it implies someone who is boringly focused on work or school — like your physics major friend “the science wonk.” Extreme fans of politics are sometimes called policy wonks.}}
Anyhow, roughly it means the “warming effects” due or forced from an increase in CO2 levels. Or generally, it’s imagined CO2 causes increase in global water vapor- and it can take
“some amount of time” to do this.
“There are three main measures of climate sensitivity that scientists use. The first is equilibrium climate sensitivity (ECS). The Earth’s climate takes time to adjust to changes in CO2 concentration. For example, the extra heat trapped by a doubling of CO2 will take decades to disperse down through the deep ocean. ECS is the amount of warming that will occur once all these processes have reached equilibrium.”
Not many people understand what reached equilibrium, means. Most correctly, will say, equilibrium can never happen. I tend to say roughly it takes thousands of years if not too strict about it. Main thing is suppose to increase water vapor, and water vapor is thought to be passive. Or Co2 forces and water vapor is not suppose to force {or something like that}.
“The second is transient climate response (TCR). This is the amount of warming that might occur at the time when CO2 doubles, having increased gradually by 1% each year. TCR more closely matches the way the CO2 concentration has changed in the past. It differs from ECS because the distribution of heat between the atmosphere and oceans will not yet have reached equilibrium.”
https://www.carbonbrief.org/explainer-how-scientists-estimate-climate-sensitivity
And:
“Change (IPCC) fifth assessment report, completed in 2014, gave a likely ECS range of 1.5C to 4.5C of warming for a doubling of atmospheric CO2 concentrations, but a likely TCR of only 1C to 2.5C.”
“The science is very clear there is a GHG effect and that almost all of it is from H2O and CO2, and that the net GHG warming effect is estimated to be between 26K~33K.
Logically, since H20 absorbs almost the entire LWIR spectrum and has an atmospheric concentration of around 30,000ppm, and CO2 primarily absorbs 15 micron LWIR and is at a paltry 415ppm atmospheric concentration, the vast majority of total GHG warming is from H20.”
I think we can all agree that clouds (H2O) keep the surface warmer than if there were no clouds. A cloudy winter night is warmer than a cloudless winter night. The Greenhouse Effect on a small scale.
That only works at night.
It is directly opposite in the daytime when clouds block sunshine.
I point you to this chart on Climate for you on the affect of cloud cover.
Interesting Samurai. What is your definition of GHG effect?
Dave Fair wrote –
”To deny CO2’s warming capability in an attempt to rebut CliSciFi high ECSs is cutting off your nose to spite your face.”
Either Dave cannot express himself in plain English, or he is an idiot.
“Warming capability”? CO2 can raise the temperature of thermometers? As in “increasing global temperatures” and so on?
I’d like to see somebody do that. I’ll buy a CO2 heating device that doesn’t need any other source of heat. Presumably it will function indoors, at night, during cold spells, when it is cloudy, raining, or snowing.
Only joking. Dave Fair is delusional. CO2 has no “warming capability”.
The equilibrium climate sensitivity (IPCC 1990, 1996) is defined as the change in global mean temperature, T2x, that results when the climate system, or a climate model, attains a new equilibrium with the forcing change F2x resulting from a doubling of the atmospheric CO2 concentration.
Approximately, there are 10^40 molecules of carbon dioxide in the Earth’s atmosphere. If we start with 1 molecule, then double it to get 2 molecules, we have done 1 doubling. If we double that again, 2 doublings give 4 molecules, 3 doublings give 8 molecules and so on.
133 doublings give 1.09*10^40 molecules, mathematically. (This is simply 2^N, where N is number of doublings), so in concept, our atmosphere has had 133 doublings.
Roughly, the present range of ECS as offered by various authors is between some negative value and about 9 degrees C. For the sake of demonstration, let us take a ‘popular’ value of approximately 1 ⁰C. Each doubling then raises the temperature by 1 ⁰C.
Because there have been 133 doublings, we should have seen a temperature change of 133 degrees C. We appear to have NOT seen this change. How can this be explained? Several options exist.
1. The ECS is much smaller than 1 ⁰C. To match observations, ECS would need to be 1/100 of 1 ⁰C, or 0.01 ⁰C.
2. Maybe, it is incorrect in theory to start the doubling calculations as I have done, from 1 molecule. If so, what is the ‘correct’ point to start the doubling calculations, and WHY that point?
3. The effect of doubling does not follow a simple relation that each doubling produces the same temperature change. That is, the IPCC definition is incorrect, or lacks some caveat(s).
4. Possibly, the Earth system copes with any temperature changes from variations in CO2 concentration by compensating mechanisms that produce an effective ECS that is close to zero and not as high as 1 ⁰C.
5. More explanations – welcomed.
Geoff S
Geoff,
You wrote –
“More explanations – welcomed.”
Oh well. To paraphrase Mark Twain, maybe reports of the IPCC’s competence have been greatly exaggerated. Maybe they share a common fantasy, in which they actually know what they are talking about.The facts might indicate the opposite.
“Approximately, there are 10^40 molecules of carbon dioxide in the Earth’s atmosphere. If we start with 1 molecule, then double it to get 2 molecules, we have done 1 doubling. If we double that again, 2 doublings give 4 molecules, 3 doublings give 8 molecules and so on.”
I think one have start with say 1 million per square km, so
510 million million molecules.
So that is 1 molecule per square meter or 1 molecule in 10 tons of air.
Though probably be more reasonable say 1 billion per square km
gbaikai,
What is your reasoning for starting at 1 million sq km? We are discussing the temperature change from a CO2 doubling. Geoff S
Geoff; the logarithmic relationship where each doubling contributes about the same amount of warming starts when the line center saturates. It occurs because the line shape is close to gaussian and each doubling is equivalent to convolving the gaussian with itself. Convolving a gaussian with itself yields a new gaussian with a wider spread ie: it absorbs over a larger range of wavelengths.
Spectroscopists use the term absorbance where 1 absorbance is a path length which absorb 90% of the incident radiation- at the wavelength corresponding to the line center. Double the column or double the concentration and the first half absorbs 90% while the second absorbs 90% of the remaining 10% so in total 99%. 3 absorbance = 99.9% absorbed and so on. At present the CO2 column is about 3000 abs. So depending on whether you define saturation as 1 absorbance or maybe 2 absorbance there are about 10-11 doublings above saturation not the 133 you refer to.
Thank you Michael H,
Yes, As a former spectroscopist, I am aware of that convention and its convenient outcome in allowing conventinal instruments to see just enough and not too much absorbance, but can you fault my logic?
Geoff S
Geoff; I am not exactly sure what logic you are referring to. If we assume 10 doublings from saturation and 3 watts/sqM per doubling that gives 30 watts/sqM total impact of CO2 which is about what is being claimed. But does that mean CO2 contributes 10C of warming? No I absolutely do not think so, any more than I think the Earth would be 33C colder if water vapour and CO2 were not GHG’s. As I keep mentioning over and over, the reduction in OLR is only one of the impacts of GHG’s.
The atmosphere acts as the working fluid of a heat engine converting thermal solar energy into mechanical energy (wind rain etc). Such a heat engine needs to conform to the principles discovered by Carnot in the late 18th century. Most specifically that there must be a hot junction where energy enters the working fluid and a cold junction where heat leaves the working fluid. The cold junction is at the tropopause (or lower stratosphere) and is created by GHG’s. Without GHG’s there is no cold junction and thus no heat engine. That means a completely saturated isothermal atmosphere. No convection, no evaporation, no rain, no wind, no clouds etc. Without evaporation and convection the conditions at noon on a clear day in in summer would be exactly the same as in a closed car for the same reasons. Here at 37S temperatures rise to well over 70C and kill people in minutes. GHG’s act to ameliorate temperatures raising minima and lowering maxima. So why wouldn’t a small increase simply ameliorate temperatures a bit more. After all, if they reduce the surface radiation to space that means the extra retained energy is coupled into the working fluid which improves the heat engine efficiency so more clouds (cooling – negative feedback) more rain, lower maxima and higher minima.
To me the most compelling evidence is the plot of OLR over time as published by NASA. If CAGW were true we should see OLR falling as CO2 rises (especially since the advocates claim Earth has a long time constant with significant locked in warming ie: temperature not in equilibrium). But in fact OLR is rising as Earth warms and rising at 3 watts/sqM/C which is the claimed thermal sensitivity of Earth. That means there is no discernible impact of rising CO2 on OLR which in my book disproves the theory.
Michael,
You seem to dismiss any energy effect from CO2 at concentrations below your your chosen start point. Why?
The logic to which I refer is the simple count of doublings as I expressed it. Do you agree that we have had about 133 doublings so far? Geoff S
Hi Geoff; yes I did more or less ignore any energy effect from CO2 below about 1 absorbance for the atmospheric column. The reason is that the absorption line starts off very narrow so that it intercepts very little energy. The impact of GHG’s really only starts to become significant after the central peak saturates. Not rigorously true of course but a not unreasonable approximation. Maybe it would be better to assume the total impact up to 1 abs would be again about 3 watts/sqM. In which case 3 watts/sqM/doubling plus 3 watts/sqM for the impact up to 1 abs.
No you cannot start doubling from 1 molecule, where in the atmosphere would that molecule be. Not only would its absorption line be really narrow it would also spatially absorb essentially nothing of the total emission from the millions of sq km comprising Earth’s surface – maybe over 1 square millimeter somewhere over the great australian desert? Until there are enough molecules of CO2 to uniformly blanket the Earth at least to a reasonable fraction of an absorbance unit there is no impact. I would contend that 10 doublings is a far more reasonable approximation.
“4. Possibly, the Earth system copes with any temperature changes from variations in CO2 concentration by compensating mechanisms that produce an effective ECS that is close to zero and not as high as 1 ⁰C.”
That’s the way I’m leaning. CO2 doesn’t look like the driving force at any time other than from 1979 to 1998, and that correlation seems to be a coincidence between a natural, cyclic temperature uptrend and the end of World War II, which led to the production of a lot of CO2 after that period. The three decade period of cooling that preceeded 1979, took place while CO2 was increasing all during that time.
But the temperature increases beginning around 1979 have stalled out since 1998, while CO2 concentrations have continued to climb, and recent temperatures are cooling substantially. CO2 seems to have little or no effect on the temperatures.
Yes, how does monotonic increases in CO2 create Step changes in temperature followed by platues or cooling?
It couldn’t possibly be the case that each doubling would have the same effect over the entire range you are considering. Doubling from 1 molecule to 2 in Earth’s atmosphere certainly would not be expected to raise the temperature by a degree.
I am quite certain the IPCC is not claiming that ALL doublings of CO₂ lead the to the same temperature change. I’m sure they are focused only on the value for doublings within a few doublings of the current atmospheric concentration. That would seem to me to be a perfectly reasonable thing to do.
RUD;
There have been indeed a number of somewhat negative responses to Dr Wentworths’s article, mine included. The problem is Dr Wentworth looks at radiative loss in complete isolation from anything else and shows how the presence of GHG’s reduces the energy loss – ASSUMING NOTHING ELSE AT ALL CHANGES. He is right but this proviso makes the entire exercise pointless in any meaningful way. It leads him to claim that if there were no GHG’s the world would be around 30C colder and that is plain wrong! The reason is that while GHG’s do reduce energy loss to space they also have other direct effects which cannot be ignored. Just one example, as I tried to point out in my comments on his thread if there were no GHG’s there would be no clouds or atmospheric dust so Earth’s albedo would be far lower and Earth would absorbing closer to 340 watt/sqM not the current 234 watts/sqM. To point out in detail how GHG’s reduce energy loss while ignoring that they also reduce energy gain is hugely misleading and leads to wrong impressions.
As I tried to point out, no GHG’s would also mean no weather, no rain, no wind, no clouds, no convection etc (because GHG’s create the cold junction of the atmospheric heat engine). The implication would be that at latitude 37S where I am the noon summer temperature would not get occasionally to 40C as happens now but would routinely get to over 80C which would rapidly kill everyone.
On a very practical point, if one simply accepts Dr Wentworth’s analysis as a realistic picture of reality one would have to assume that as CO2 rises, Earth’s energy loss to space ie: Outgoing long wave radiation or OLR for short would be decreasing which is what would be driving the warming. Maybe if one assumed Earth as a whole had a very short thermal time constant one could claim Earth was always in thermal equilibrium in which case OLR would remain constant as the Earth warmed. However what the NASA data shows is that Earth’s energy loss to space is rising as Earth warms and is rising at about 3 watts/sqM/C which is exactly the thermal sensitivity claimed for Earth as a whole. That implies OLR is simply determined by Earth’s temperature and rising CO2 has no discernible impact. In fact Earth is not warming due to falling OLR but due to rising absorbed solar radiation (ASR) and that appears to be due to falling cloud cover. What causes the falling cloud cover is of course the “$64 question”
I do NOT claim that “It leads him to claim that if there were no GHG’s the world would be around 30C colder.”
I claim that, if you could remove the radiative effects of GHGs (and other materials) while holding albedo and emissivity constant, then the world would need to be at least 24℃ colder.
This is a thought experiment, not something could really do. It is NOT equivalent to “removing all GHGs”, as you correctly point out.
It’s not, rigorously, a statement about what would happen if one removed all GHGs (although it is often misinterpreted as that), but that doesn’t make it meaningless.
It answers an important question: “Do the LW radiative properties of materials in atmosphere play an important role in allowing the planet to achieve its current temperature?” The answer is an unequivocal “Yes.”
People keep insisting that it would be more meaningful to look at “What would really happen if you removed all the GHGs?”
That’s a useful and important question. But, it’s not the only useful and important question.
In scientific experiments, if you want to find out the importance of one variable, it is traditional to look for ways of isolating the effect of that one variable. You don’t go changing 15 different variables at the same time, and expect to get any clear result.
So, if you want to answer the question, “Are the radiative properties of GHGs important in setting the planet’s temperature?” then it is natural and useful to look at what would happen if you could change those radiative properties without changing anything else.
It turns out that (as my analysis showed), one can make some clear statements about what would happen if you could change the radiative properties of GHGs without changing the key factors of albedo and emissivity (though everything else is allowed to vary).
The answer to that question tells us that the radiative properties of GHGs play a really important role–all other things being equal.
It’s true that the question of what would happen if you removed GHGs (and not just the radiative properties, holding other radiative properties in the system fixed) is an important question, and possibly a more useful question than the question that was answered.
But, this is a vastly more difficult question to answer.
Answering the question that we easily could answer still offers some insights.
It tells us that, although albedo and emissivity might change if one removed GHGS, for any combination of albedo and emissivity that might emerge, we could still put some bounds on what could happen with and without the radiative properties of GHGS.
It remains useful information, even if it’s a subtler bit of information than what we would most like to know.
Yes. The commendable and most valuable thing about WUWT is that, unlike Ars or Real Climate or the egregious SkepticalScience, it carries posts that rebut the wilder fringes of skeptical opinion, and it permits pretty free debate about them.
On Ars for instance you regularly find people posting that civilization is going to be doomed unless… various idiotic things are done…. which will have no effect on global CO2 levels. Any views to the contrary are promptly voted down to invisibility and the posters banned in short order.
These last two posts on the GHG are obviously correct. Its real, it can be quantified. This is not where the problem is with climate alarmism.
The problem is with the passage from the GHG, which is a matter of physics, to the effect on the climate of the warming influence of GHG on the planet, which is a matter of engineering, so to speak.
I have previously compared it to the mileage you get from a gallon of gas. You cannot estimate this from the energy content of the gas. You have to know the specifics of the design of the vehicle, weight, wind resistance, losses due to heat, efficiency of transmission…
The question is not how much of a warming impulse a rise in CO2 has. We know the answer to that. The question is what that warming impulse does to the climate of the planet we are living on. And it depends how the planet works.
Take a much simpler example, you turn up the heat under a pan of water. Then you try to estimate how the temperature of the water will rise under the influence of that heat. But you cannot tell from the amount of heat you are applying. You have to take account of the way water behaves at this atmospheric pressure.
The planetary climate could respond to rises in CO2 by simple warming, by warming accelerated by feedbacks, by triggering a cyclical damping effect so there is little or no long term warming.
Absent any other changes a simple doubling of CO2 ppm will lead to a planetary warming of about 1C. The problem is that there will be other changes as a result of the application of this warming effect. If you are crazed alarmists you try and find reasons to think the end conclusion will be 4C+, and your propaganda will claim that the high number is ‘just physics’.
It isn’t, any more than the mileage our car gets in the first example is ‘just physics’. It happens in accordance with the laws of physics, like everything else, but how these laws work out in this instance and what end result the warming delivers is a matter of how the car or the planetary climate functions.
The rational and science based conclusion about human emissions, rises in CO2 ppm and global warming is that there is a warming effect from rising ppm, the GHG, but that it is not of a magnitude to cause any disastrous effects, because the reaction of the climate of this particular planet to it is not for this slight warming, or any other slight warming, to amplify it through feedback. Other planets differently constituted might respond differently, just like three or four different cars might get different mileages. But on the one we are living on, there is no grounds for alarm.
On the contrary, there seem to be dampening mechanisms which limit small warmings of this sort, however caused.
Michel,
You claim :Absent any other changes a simple doubling of CO2 ppm will lead to a planetary warming of about 1C.:
Did you not read what I wrote just above you here?
If you can answer my questions, I’d love to hear. Geoff S
Yes, I read it, but didn’t understand the argument properly. With the 1C figure I was just following the almost universally accepted account as I understand it.
Is maybe the thing wrong with your account that it doesn’t take account of the absolute amount of CO2 in the atmosphere, which is the thing that will drive total heat absorption? And its total heat absorbed that will affect the climate. I am not sure I understand your argument well enough to know if this is a proper counterargument though.
Martin,
It is a proper counterargument. Think about it, read it again and if you must then give an opinion, or would you at least give the reasons why you formed that opinion?
Geoff S
“ignores convection (true, but convention only moves heat around in the atmosphere; it cannot not make it go away like radiation to space does)”
Unless the emitted photon has a free path to space then radiation too is just ‘moving heat around the atmosphere and go away to space’
The fact is convection, and particularly that which takes with it water vapour, moves huge amounts of heat from the surface to the top of the troposphere, where at least it is closer to space. It takes 5.5 times as much energy to evaporate water as take it from 0 C to 100 C, evaporation, convection, and clouds/rain move a staggering amount of heat.
“to even the very old gravitational density heating canard”
Yet there is a lapse rate….
Thank you.
Thank you Rud,
Thank you Bob,
and the other voices of reason.
“The surprisingly controversial post’s conclusion is also easily personally verified by simple observation. Tyndall proved in 1859 that both CO2 and H2O were GHG, while N2 and O2 are not.”
.
A few comments.
There is still life in being a skeptic.
The science is not settled.
CO2 is a GHG.
An increase in its concentration in the atmosphere will lead to some degree of warming.
Feedbacks have not been proven to anyone’s satisfaction.
–
Taking a strong position on warming leads to shutting one’s mind to inconvenient facts, shouting down the opposition and taking a cargo cultist approach to science.
Basically if one can disprove the GHG theory, the feedback theory, the measurements theory then magically global warming, as a theory, will be wrong.
–
I see a lot of otherwise good scientists on both sides foam at the mouth and strain logic and commonsense in their efforts to denigrate their opponents and their opponents arguments.
–
Good arguments do not win discussions, but they help.
Bad arguments with good motives may win discussions but do not help.
One way or another time will sort it out.
The side with the best case does not always win.
–
In times like these I like to listen to the arguments of the more sensible people with open minds.
Judith Curry, Roy Spencer and Rud Istvan.
People who wish to disagree with them and their views have to put up some pretty good arguments and I do not see any yet.
–
So come on. Put up a few sensible arguments.
To summarize without any math, the GHE exists. It experimentally must, and easily provably does. The GHE issues are how much when (ECS), not if. Any ‘skeptical’ arguments to the contrary are fairly easily rebutted, as done here.
Thankyou! about time we started the debate from a point of the settled physics!
“Fine IR scale matters.”
Generically, narrow structures widen as the concentration (or energy levels) increase. I would be surprised if the environmental measurements of LW radiation can see this. Is my definition of “Fine”, 4 wavenumber resolution and lower, off for climate studies?
Rud – there may be a problem with what people understand when the words “greenhouse effect” are used. Seems some people interpret it as being totally or largely on the amount of CO2 in the air, and others look at it as a result of the combined CO2 and H2O in the air. It seems pretty intuitive that if you impede the outgoing radiation from the ground then the ground will reach equilibrium at a higher temperature than if there was not such an impedance (no greenhouse (or more precisely absorptive/radiative at the relevant temperatures) gases in the atmosphere).
Thus there seems little reason to doubt that our world is going to be warmer with greenhouse gases in the atmosphere than it would be if they weren’t there.
However, we receive solar radiation which adds energy to the system, and the only way the Earth can lose energy is also by radiation. AFAIK the water vapour in the atmosphere largely stays in the troposphere, and thus the main radiation must come from the non-condensing radiative gases in the stratosphere. There’s also the “window to space” at around 10 micron wavelength where radiation from the ground level passes through the entire atmosphere with little absorption, and recently there have been a few products (metamaterials) that utilise that window and provide passive cooling of up to 10°C relative to normal surfaces. The point here is that the wavelength is critical and that a lot of diagrams of “heat flows” showing the greenhouse effect are over-simplified to the point of being just wrong.
Your first diagram in the article is pretty important. Solar radiation coming in at 5780K or so – though again that’s a bit variable so we’re looking at an average, and as the UV intensity changes where the energy is absorbed will change. Outgoing radiation at 255K – and again that’s averaged, and even that 255K is an average of the air temperature at somewhere around 1.2m above ground rather than the radiation from the ground itself which will normally be a different temperature than the air above it.
“GHG are saturated, so can have not have any further effect. This misunderstands saturation, since it depends on the effective radiative level (ERL). As CO2 increases, the ERL rises unconstrained, since CO2 is unaffected by the lapse rate, while H2O is and so decreases.”
for temperature versus height. I don’t however know what the ERL actually is. Thus figuring out whether an increase of CO2 in the atmosphere will affect the air temperature at 1.2m above ground level from first principles is a bit difficult – I expect there will be an effect but the question is exactly how much.
Yep, the ERL will rise with increased CO2, and will thus have an increased area and will radiate more energy – but of course as the ERL goes up then the temperature will also vary. See
Then there’s Greg Wrightstone’s “fact checking the fact checkers” post. An important plot here is
?ssl=1 . OK, there are problems in defining “average global temperature” since what we normally measure is the air temperature at between a metre or two above ground, and it’s normally measured where people live, and the changes in weather-station locations over time as well as changes in the sensors used and the time of day of the observations means that we’re not comparing apples with apples, but let’s sweep those problems under the carpet for a bit and just accept that Greg’s plots are near-enough accurate to use. The implication is that we can’t see any definite CO2 signal there. Another important article here is https://wattsupwiththat.com/2020/09/15/cooling-the-hothouse/ where Willis plots the temperature versus CO2 concentration over 67 million years. Sorry, but I’m also one of the “Willis groupies” here since he works things from first principles and analyses the data rather than changing it to suit his theories. Again, in that plot we can’t see any effect of CO2 on temperature. Another important article from Willis is https://wattsupwiththat.com/2021/05/20/the-1-5c-hysteria/ which points out the lack of connection between the CO2 levels and temperature changes, and underlines the stuff that isn’t explained by the GHG theory.
Thus on the short-term we’re not seeing any major effect of CO2 on ground-level air temperatures, and also we’re not seeing any effect long-term. We should thus question our intuitive deduction that adding CO2 to the atmosphere will increase the temperatures we measure. The data implies that if it happens then it’s minimal and probably below the threshold of measurement.
For me, the net result is that though the “downwelling LWIR” obviously exists, and we can measure it, and it means that our world is (pleasantly) warmer than it would be without it, I’m not seeing any major change in that that depends on the change in the amount of CO2 in the atmosphere. There must be some change, but it is maybe compensated by something else such that the net result is too small to be certain of.
“to even the very old gravitational density heating canard (ignoring that since Earths atmosphere got densified (aka ‘pumped up’) by gravitational consolidation about 4.5 billions years ago, unlike a newly pressurized bicycle tire it has had a LONG time to cool back down).”
This sentence caused me to reconsider that theory. The point here is that the cycling of air rising and falling in the troposphere is still going on today, and thus the energy from the ground is conducted into air at ground level reducing density as it warms, together with water vapour reducing the density until it’s risen far enough to cool enough to condense out into clouds, but the radiation is largely impeded by being absorbed/re-radiated thus having a long random walk before it finally escapes. Thus the convection in the troposphere is the main energy transport from the ground to the top of the troposphere (air is continually being pressurised and de-pressurised as it falls and rises), and above that the energy is largely transferred by radiation until it reaches the ERL and finally leaves the atmosphere. We thus have the two mechanisms for the radiative loss – from the ground directly to space via the 10-micron “window”, and from the ERL to space with the radiative lines (broadened by temperature/pressure) of CO2 and maybe a bit from H2O. It thus makes sense that the ground-level temperature will depend to some extent (maybe even a large extent) on the temperature at the top of the troposphere and the lapse rate from that level down to ground. My main observation here is that unlike a bicycle tyre that you pump the air in and then it cools down again, here the pressurisation is constantly being performed by the convection in the troposphere. Descending air will warm up as it gets pressurised, and so the equilibrium temperature at the top of the troposphere (where the only energy loss will be by radiation) is important.
I thus think that “that old canard” shouldn’t be rejected. It’s not the whole answer, since the 10-micron ground radiation is also important, but it should be part of the answer. The only way we can lose energy is by radiation, and the CO2 radiation is from the ERL and not ground-level.
The bottom-line question is “what will we measure as a change in temperature if we had double the amount of CO2 in the atmosphere”. If we look at the measured temperatures and those inferred from proxies, and we compare that against the measured CO2 in the air and those inferred from ice-cores, stomata sizes in fossils, and other methods, it seems that the answer is “bugger-all”.
Thus the data tells us that both transient climate sensitivity and equilibrium climate sensitivity are around zero. Sure, there are correlations if we choose our dates carefully, and we can propose a TCS and ECS that will fit the data over that range, but we need to consider all the data.
We can’t explain the historical temperature changes by how much CO2 was in the air at the time. There’s however bound to be a change in CO2 concentration in the air as a result of temperature changes in the ocean, since most of the free CO2 (around 98%) is dissolved in the ocean and the solubility is very temperature-sensitive, though untangling the effects of ocean currents will be difficult since some of them are of the order of 1000 years long, and where water is cold (thus can absorb more CO2) it’s going to subsequently sink and it may be a long time before that water again reaches the surface in somewhere warmer and releases some of its absorbed CO2.
When we can explain all the previous climatic conditions, such as warmer and cooler periods, glaciations and de-glaciations, etc., then maybe we’ll have more confidence that the predictions for the future have a better chance of being right. It seems to me we’re nowhere near that level of ability yet.
I am glad you raised UV, because although there is little change in TOA, there is a much larger change in UV which needs to be taken in to account along with Cloud Cover.
ACO – yep, the spectral change does make a difference where more energy is dumped (surface or deeper). On the other hand I haven’t seen any obvious hints of an 11 or 22-year cycle in temperatures, so maybe the net effect ends up around zero. Thus it’s maybe something that ought to make an effect but doesn’t in practice.
The problem I have with the GHE is that it’s stated that more CO2 => bigger effect, and I can’t see that in the data. I’ve no problem with the existence of the effect itself, since it’s obviously going to be there and we can also measure the downwelling LWIR. However, I don’t see a change in it in the actual historical temperature data that shows it happening, given that most anthropogenic CO2 was emitted after around 1950 and the warming out of the LIA started over 100 years before that. Thus though it seems that the GHE should have increased, in practice it seems it hasn’t.
For the “gravitational” explanation, initially I rejected that for the same reason Rud did – it got compressed a very long time ago. However, the cycling of atmosphere between ground and the top of the troposphere is always happening, so it’s being pumped like a cycle tyre now, and thus it’s the ERL (a sort of average height where the radiation to space effectively occurs from) that gains some importance. I don’t however know what the ERL is for other planets (or the Earth) so all I’m noting there is that the idea shouldn’t be rejected. It needs more discussions, and it should be possible to observe the ERL if we have the right spectral response in the telescopes. Thus we should be able to get the experimental evidence to support the proposal.
Overall, though, just looking at the history we know, a few degrees warmer isn’t going to hurt us – there’s a reason the historians call such times Climate Optimums. It does however look likely that it’s going to get somewhat colder, though precisely when remains unknown. In history those colder times haven’t been good times to live. Thus the AGW scare means we’re preparing for the wrong eventuality, and at the same time reducing our ability to cope with it. Not exactly clever….
Simon, I agree with just about all of that.
The proble with UV is that it could be going in to deep ocean where we do not have any real idea of any time lags involved.
For instance it could be the source for the energy for El Ninos.
“there are problems in defining “average global temperature” since what we normally measure is the air temperature at between a metre or two above ground, “
That is because human want to know the air temperature.
Global average surface temperature {not global average surface air temperature}
Is the average temperature of the Ocean, which about 3.5 C.
If we were fish, we would have right average global surface temperature.
Or global temperature has always been known to long term average temperature.
The average ocean is a long term temperature. And ocean has 1000 times more heat per K
of temperature. Ocean average temperature is global climate temperature.
And as some have said the warming deep ocean water is more than 90% of warming which occurred in last 50 years {because only starting measuring accurately, it recently]
What doing by measuring surface air temperature, is trying to measure the ocean, or it’s assumed if air stay warm enough and long enough it will warm the ocean.
It’s like looking for your keys under the street light, cause that where the light is.
If you’re going to shoot down the atmosphere compression idea, at least you could explain why on Earth and Venus, at the altitude where the pressure is half the surface level (ie half the mass of the atmosphere is below that height and half above), the temperature is the expected black body temp? It seems like the atmosphere is acting like a black body, to the extent it is averaging out the energy absorbed according to mass, and there is more mass closer to the surface than above, according to the temperature gradient. No pump needed.
Good one 99. Can you supply figures or a reference? Venus is a real fly in the GHE’s ointment.
I just looked up the temperature vs altitude curve for Earth and for Venus, matched that with the pressures at surface and altitude, from NASA mostly.
Wiki:
0 meter “sea level” 462 C 92.10 atm
10 km 385 C 47.39 atm
https://en.wikipedia.org/wiki/Atmosphere_of_Venus
And 92.1 atm / 2 = 46.05 atm
Or roughly 1/2 the mass of Venus is around 10 km or less above this zero elevation.
Though one might argue about how or why sea level is used or determined.
But it would less then 10,000 above this “sea level” elevation- or this averaged elevation of the rocky surface of Venus.
How is number somewhere around 385 C “the expected black body temp”
As compared 462 C at the mean average elevation of 0 meter not being “the expected black body temp”.
As far as earth goes it is commonly said 5.3 km elevation has 1/2 atmospheric mass below it {or 1/2 mass above it].
And just plug in average numbers, you could times 5.3 by lapse of 6.5 C =
34.45 C
So average global surface air temperature:
Land: 10 C and Ocean: 17 C and average global 15 C
15 – 34.45 = -19.45 C
The minus 19 C is close to cargo cult number of blackbody minus the reflected sunlight. Or Earth roughly radiates about 240 watts. minus 19 C or 254 K temperature of blackbody in vacuum of space emits 236 watts per square meter.
Now the cargo cult imagine at around 1/2 atm is where earth cools, are we suppose to follow the same foolishness and assume at 1/2 atm of Venus is somewhere that Venus cools.
I happen to think Earth land and ocean surface is where it cools, and with Venus it cools at it’s cloudy surface. And if Earth was completely covered with thick clouds, and no warmth of sunlight reach the Earth’s surface, then also likewise I would count the only warmed surface {these earth clouds} as where it cools to space.
[unless I didn’t think the sun was large factor warming the planet surface- for instance the gas giants temperature is not due to them being warmed from the sun- it’s all about their internal heat.
Thanks gbaike. My numbers didn’t come to the blackbody at the atmospheric midpoint either. But it’s clear that at Venutian 1atm altitude, solar proximity explains the temperature perfectly, frankly nullifying the back radiation theory all by itself.
If you want to disregard evidence from our closest neighbour with an atmosphere, this phenomenon has to be explained first.
Venus rocky surface is dim and not heated by direct sunlight at rocky surface. Earth is somewhat dim at it’s surface, but is heated at it’s surface.
Venus heated surface is the clouds which are high elevation.
Is that really true for Venus? That seems very unlikely to me.
And, when you say “black body temp”, I hope you’re not treating Venus as an absorptive black body, ignoring the fact that it reflects 75 percent of incident radiation? Because anything that ignores that is clear nonsense, from a physics perspective. Anything based on ignoring how much energy is absorbed would amount to fishing for coincidences.
reflective is about amount of energy absorbed, and not really anything about temperature. Or reflecting surface can [and usually are} hotter in vacuum than blackbody surface, but blackbody surface absorbs the most {and of course emits the
most in a vacuum.
Venus reflects a lot because of it’s acid clouds [droplets of concentrated acid}. But also reflect a fair amount even if the atmosphere didn’t any clouds.
Any significant atmosphere even though it reflects sunlight should increase average temperature of a planet {or any spherical body].
But I argue that with large atmosphere of Venus, Venus at earth distance should be colder than Earth. This because Venus is warmed with twice as much sunlight at it’s distance, and this sunlight can warm the acid clouds, whereas at Earth distance the sunlight is not strong enough to warm the acid clouds {by very much}. Or Venus clouds do not absorb much sunlight, but can absorb enough with intense sunlight.
So at Earth distance Venus would have “runaway cooling” and all atmosphere and less bright sunlight, the rocky surface would a lot dimmer than it currently is.
The only alternative view is Venus has a source internal heat, due to volcanic heat or impactor heat. But they say that on Venus the acid is a greenhouse gas- and I say it would not be a “greenhouse gas” at Earth distance.
Venus absorbs less sunlight than Earth. Despite being closer to the Sun, it reflects most of the sunlight that is incident on it.
Only the absorbed sunlight counts, with regard to temperature.
I don’t see what point you are trying to make, in speculating about what the temperature of Venus would be if it were in the orbit of Earth.
“Venus absorbs less sunlight than Earth. Despite being closer to the Sun, it reflects most of the sunlight that is incident on it.”
Yes and Venus emits less energy than Earth
“Only the absorbed sunlight counts, with regard to temperature.”
It’s terms of effective temperature or planetary equilibrium temperature:
https://en.wikipedia.org/wiki/Planetary_equilibrium_temperature
https://en.wikipedia.org/wiki/Effective_temperature
“I don’t see what point you are trying to make, in speculating about what the temperature of Venus would be if it were in the orbit of Earth.”
A theory such as greenhouse effect theory should be able to predict this. My point is to indicate what “my theory” or what I understand about any theory would predict.
What does anyone else predict would happen if Venus received 1/2 as sunlight as it currently does?
I also would predict if Earth would get twice as much sunlight it would result [within millions of years] in Earth being like Venus. Earth at Venus distance would could “habitable”- though certainly hotter. And things our roads would melt- they already can, but I mean one have make concrete roads.
“…it would result [within millions of years]..” I meant:
it would *not* result [within millions of years] in Earth being like Venus.
Though that is not surprising.
But oceans nor muddle puddles would boil. {maybe that might surprising]. And would take hundreds thousands of year for earth ocean to get close to equilibrium temperature. And no runaway effect of type CAGW end of world hysteria. But certainly quite few problems with twice as much sunlight.
And solar energy with twice as much sun, still would not work [not be viable way to get electrical energy].
Plus these problems of twice as much sunlight could be cheaply solved {for less than 1 trillion dollars- or, far less than already wasted not solving “global warming”.
{money thrown away pretending any government can solve a problem- and not problem because we are living in a Ice Age- or 10 degree below Earth’s “normal temperature”.}
What would be the temperature of the surface if it were a perfect IR mirror for temperatures less than 50 C? If you can’t answer that question then you will likely not be able to figure out anything about the greenhouse effect.
Your answer can be anything you want after you introduce a singularity in a “perfect IR mirror” that doesn’t exist. No one can prove you wrong…or right.
It’s a thought experiment.
This would appear to be an incoherent question, with the inclusion of “for temperatures less than 50 C”. I don’t know what that constraint is supposed to mean. Do you mean for wavelengths longer than some particular wavelength?
Bob, it was meant to limit the reflection to IR radiated by GHGs. Did not want anyone including solar generated IR. Maybe that’s what I should have said. The result would be the same amount of solar energy absorbed by the surface but no GHG produced IR absorbed by the surface.
Rud,
Good post as usual. The graphic you provided on intensity of Earth emissions shows a large region at maximum intensity around 9-10 microns that is quite a window of relatively free emission to space and covers a large area under the curve. Also there is another large range/region at wave lengths greater than CO2 that is emitted by H2O. Seems C02 has a relatively small niche.
My question is: Is the particular wavelength dependent upon temperature at the point of reemission at altitude that would be at a lower temperature regarding either C02 or H20? I’m focused on properties of cloud tops where the LW emission is coming from liquid water or ice.
I’ve been waiting for a long time to resolve this in my mind and thought this past week would offer an opportunity but the threads are going to 400 – 800 comments.
It (radiation) has generated a lot of interest and discussion. It’s a hot topic for sure.
For the earth to absorb radiant energy from the sun, it has to be cooler on the surface than the sun is (even a degree), as heat flux finds its way to the least resistance energy sink, as energy migrates from the hotter to cooler surfaces in the universe.
In a vacuum, two identical surface temperature spheres (suns, moons, planets) within a non – destructive distance from each other will not absorb each other’s energy (rotation rates neglected). Neither would loose or gain energy from the other, although any other cooler surfaced bodies in the region (for lack of a better term) would gain heat until their surface temperatures became = to them. In the end, all would be = in temperature (max entropy).
As the sun’s fractional luminance at our distance (1/(4xpiixR^2)) warms the earth’s surface, the warmer the earth’s surface gets, the less energy (heat flux) is transferred per unit time, within the confines of the particular area of the imaginary sphere around the sun at our 93e6 mi from it.
When the earth’s surface temperature increases, either from GHE, something else striking it, or a fractionally higher rate of incoming solar irradiance from a higher surface temperature sun, the temperature difference between it and the sun’s surface, that controls all energy transfer (heat flux) flow rates, reduces immediately.
A new point is continually reached (time lag) where the outflowing radiation rate (i.e. dark side) increased (higher earth surface temp) and then in time == the new incoming radiation rate (daylight side), which had decreased (less surface temp differential). A new stability continually is reached (time lag).
When additional GHE from the C02 molecules raises total incoming radiation (as a separate fractional amount proportional to the original outgoing radiation from surface, and was immediately reflected back to the earth (many loops in circular continual fashion), the new incoming heat flow source does not add to what was incoming from the sun, it replaced that fraction of it.
If it had freely (without resistance) added to the flux incoming from the sun in this ‘radiation’ circuit, then the earth’s surface would have no upper bound, as even radiation energy on the dark side of the earth would be partially reflected back. In all cases, more energy is coming in than is being released to space. Essentially an OPAMP with positive feed-back. In microseconds, an OPAMP’s output will hit the rail supply voltage with positive feed back, and these make fast and robust latch circuits.