TBYJ, in that explanation are you assuming an atmosphere without water vapour (or other GHG) and a linear (not log) response?

Yes, I dealt with the log problem in a much earlier post a few years ago This brings the fag-packet sensitivity down to about 1.8K Water vapour accounts for the majority of the other 70-80%.

The idea of this wasn't so much to peg a figure for sensitivity, but just to show RR et al that there is an empirical basis for the idea that CO2 bats above its weight in effect and that the trace argument is irrelevant.

Good question, but it's not a flaw as such (I was simplifying like mad to make a point about CO2 contributions), but yes it does alter the proportions, although not massively. H2O and CO2 do overlap over some of this range.

Here's another graph - note the section which corresponds to the previous graph is from around 7 - 20 microns.

The interesting thing about comparing these two graphs (apart from the annoyance that the direction of increasing wavelength is opposite and one is log and the other not!) is that over the 'interesting' range - i.e. from about 10-20 microns, CO2 has a massive peak, being back down at zero again by the time you get to 20 microns. H2O on the other hand, is rising steadily from zero to maximum over this range.

So yes, H2O is contributing to the peak in emissivity that I (for simplicity) attributed to CO2 alone. So you could argue (for instance) that the CO2 contribution is say (to be generous to the H2O contribution) 50% of what I assumed before. Say 13% of the entire effect instead of 25%. From that we get 0.975 degrees warming for out 100ppm. I can live with that.

The point of the exercise wasn't to pin down an exact proportion, but to demonstrate that CO2 bats above its weight in terms of contribution, so that arguments about the relative concentrations of the gases (or the 'trace gas' argument as I call it) are unfounded. CO2 is not the most important GH gas, but it's an important one, and we need to stop trying to prove it has no influence - it does.

PS. I don't like punching :)

Well, although I've spent the last few posts convincing you that increasing CO2 from trace levels to slightly more than trace levels can potentially raise the temperature by a good chunk of temperature, I'm now going to go back on it and say that it probably won't.

Not because the GHE is not happening, but because the GHE is only one vector acting on temperature. I get annoyed when people claim that the GHE is 'disproved' because the temperatures aren't rising any more. It's more that the complex feedback control systems of the earth are coming into play.

Next time a warmist says that the reason there's a pause is because the energy that was going into raising the temperatures is now being absorbed by other earth systems, then congratulate them on becoming a sceptic - because it's these OTHER earth systems that we have been calling feedbacks for years. It gets hotter, it gets more rainy.. it stops getting hotter. At last, mainstream climate science is coming round to our way of thinking about feedbacks.

"It isn’t the GHE that I think is total bunkum,..."

Well, yesterday it was indeed the GHE that you thought was bunkum. Now that it has been explained to you, you realise it is not. That is progress of sorts (except that I'm not sure anybody else on this thread has accepted TBYJ' explanation). But you now think x,y,z are bunkum and it hasn't occurred to you that maybe you just don't understand them either.

"...energy that was going into raising the temperatures is now being absorbed by other earth systems ... it's these OTHER earth systems that we have been calling feedbacks for years."

You might have been using the word "feedback" to describe "energy that was going into raising the temperatures [that] is now being absorbed by other earth systems". But you are wrong, that is not a feedback. I've found that many skeptics, even some who call themselves engineers, have little idea what feedback is. So you are not alone. Energy being absorbed by other systems is certainly not a feedback. For feedback you need to close the loop.

"It gets hotter, it gets more rainy.. it stops getting hotter."

Now if the increase in rain were to be a direct result of getting hotter and if the stopping were a result of the increase in rain, that would indeed be a feedback. But can you prove that it exists?

Oh Raff, I understand what a feedback is, back from the days when I had to endure many a lecture in my Feedbacks and Systems lectures in the draughty Victorian lecture physiology theatre at Glasgow University, through my various thesis projects working on signalling and my home electronics projects, and then onto my seven years working on analogue and data transmission research at a major telco research labs. If you're in the UK, you may be using a bit of kit that came out of a piece of Shannon-Hartley research I did back in the early 90s. So now that my schlong is on the table, where's yours, where iare your credentials, as it were?

You like to bandy the term "close the loop" as if I don't understand what it means, unfortunately all it does is demonstrate why you don't understand climate systems, and in particular the 'earth system' I described in the very post you are attempting to critique. Don't worry, you're in good company, the world is full of supercilious little science-banner-wavers who don't actually understand their little religion either, but who go about accusing those who do of ignorance. Well done.

If you can't understand why heat energy going into the hydrological cycle and producing more gaseous H2O is a feedback, then I'm afraid I can't help you. But then we already know you don't want help, don't we?

Twat.

It doesn't matter how qualified you think you are (and many people here, when told how qualified is person is, will start throwing around the fallacy of argument from authority - though I don't buy that myself). If you suggest that "energy that was going into raising the temperatures is now being absorbed by other earth systems", and that "it's these OTHER earth systems that we have been calling feedbacks for years" then you deserve ridicule. That isn't an example of feedback it is just heat distribution (by "earth systems"). All you do by insulting me instead of admitting your mistake is to confuse further the poor bewildered folk like Radical (and many others I suspect) who don't know the difference.

"If you can't understand why heat energy going into the hydrological cycle and producing more gaseous H2O is a feedback..."

Again, that is not feedback. It is like saying that putting heat into the kettle produces "gaseous H2O" and that this in itself is a "feedback". To make it a feedback, you need to feed it back - close the loop. You need to connect it back into either more (+ve feedback) or less (-ve feedback) heat going into the cycle, which you haven't done and can't prove one way or the other. If you could prove it you'd be popular, because climate scientists would like to know exactly what effect this has. It is ironic that you get so fired up about feedback because it is positive feedback from cycles like this (once closed) that most scientists who have studied climate think raises climate sensitivity beyond the 1C of CO2 alone.

Raff, you are showing your ignorance of both feedbacks and climate.

Putting water into a kettle IS a feedback. If the water wasn't there the kettle would be a damn sight hotter.
The heat of the kettle causes the water to be hotter, causing steam, which escapes and loses the system energy. the water doesn't do that on its own, it does it because of the kettle getting hotter and heating the water. And its behaviour when that happens affects the temperature of the kettle (cools it).

Feedback simply means that a change in one input causes a change in an output which is itself an input to the system. You don't have 'wire up' anything or 'feed anything back in' as you lamely call it.

If you don't trust my credentials on this, I insist you consult a physicist or a psychiatrist about your denial about atmospheric H2O's influence on temperature. Until that time, you are talking grade A bullcrap as per usual.

Yes, you are right.

Christmas has come early.

Ocean /Atmosphere CO2 variation

The deposition of carbonate rocks has been an ongoing process throughout the geologic record from the Proterozoic to the present. Most, but not all of this carbonate has been in oceanic deposits, deriving the necessary CO2 from the ocean /atmosphere CO2 store. The amount that is at present in this store is, however, only a very small fraction, less than 0.2 %, of the amount required to lay down the carbonates present in the geologic record. The atmospheric reservoir concentration is at present around 400 ppm of CO2. If, in the late Proterozoic CO2 concentration was as high as the +/- 8000 ppm, which is the present central estimate, the depletion to the Holocene level of +/- 200 ppm would have consumed an estimated 2000 times the present atmosphere /ocean CO2 content .

The present rate of carbonate deposition would deplete the atmosphere-ocean reservoir in something on the order of 500 ky and there is no geological reason that suggests this rate of carbonate deposition is above the Phanerozoic average. It is clear that at times in the past the rate of carbonate deposition has been much higher - for example in the Lower Carboniferous and Upper Cretaceous periods. This suggests there has been a supply renewing the atmospheric-oceanic CO2 reservoir by an aggregate of 2000 times the depletion from the late Proterozoic to the present over 1000 my – which approximates to the actual time scale of atmospheric CO2 depletion from 8000 ppm to 200ppm. A certain amount of CO2 most likely has been incorporated in coal, oil and gas deposits which, together with carbon stocks in the biosphere amounts to about 1/3 of the amount in the ocean reservoir and less than 0.05% of the amount sequestered in carbonate sediments.

There was a rapid fall in atmospheric CO2 concentration ( and presumably also in oceanic ) in the lower Carboniferous , a period of major carbonate sedimentation which was also the time when land plants first flourished. CO2 concentrations rose again in the Triassic but there was a sharp decline in the Upper Cretaceous, another period of enhanced Carbonate deposition, after which CO2 concentrations recovered in the early Tertiary before falling fairly steadily to the low Pleistocene/ Holocene levels that now prevail.

Out-gassing of juvenile carbon must have occurred to restore ocean/atmosphere reservoirs. If out-gassing had ceased it would have resulted in the death of plant life from the consumption of the content of the ocean/atmosphere reservoir of Carbon over about 500ky. The re-supply of carbon must have been from juvenile sources. Recycling of sediments cannot account for it, both for reasons of the quantities involved and for reasons of isotopic composition. If old carbonates have been removed by subduction and/or erosion and the Carbon recycled the proportion of 13C in the atmosphere would have continuously increased , and hence the younger carbonates would be isotopically heavier than older ones which is not the case. Marine carbonates of all ages back to the Archaean show the same narrow range of the carbon isotopic ratio (Schidlowski and others, 1975, )

There is thus a question as to what quantities of carbon could have been available , in what form , and in what manner re-supply of the atmospheric-oceanic CO2 reservoir could have taken place. There there were periods of intensive flood basalt volcanism at the times of the Siberian, and Deccan traps and the early Tertiary flood basalts which roughly corresponding to times of super-continent rifting and break up and flood basalt volcanism on a massive scale, both submarine and sub-aerial. These events roughly correspond to periods when the ocean/atmosphere CO2 reservoir was replenished as atmospheric CO2 concentrations appear to have risen sharply and co-incidentally.

It is thus possible that variations in atmospheric ( and oceanic) CO2 concentration have resulted from the interplay of depletion as a result of carbonate deposition and re-supply as a result of sub-aerial and submarine volcanism releasing juvenile Carbon into the ocean/ atmosphere system. This could have resulted in the very high levels of atmospheric CO2 in the late Proterozoic ( +/; 8000 ppm ) being reduced to a few hundred ppm in the Carboniferous, recovering irregularly to 1-2000ppm in the early Tertiary and declining steadily to the present low level of a few hundred ppm.

Two periods of extremely low atmospheric CO2 concentration are characterised by extensive mid latitude continental glaciation - Permo-Carboniferous, 300-320 mya and Pleistocene- Holocene, 2.3mya to the present day. Other periods of mid latitude glaciation have occurred when CO2 concentrations were much higher than either now or in the Carboniferous , at 2.4 bnya,1.0 bnya, 750 mya, 670mya, 450mya and 150my. There is no information to demonstrate that low atmospheric CO2 concentrations in the Carboniferous or Pleistocene- Holocene are either a cause or a result of low temperatures or vice versa, An excess of CO2 sequestration by carbonate deposition over re-supply by volcanism would be adequate to explain the decline in CO2 concentration. The decline in atmospheric CO2 concentration in the Devonian-Carboniferous when it fell from +/- 4000ppm to +/- 500 ppm implies the transfer of a massive volume of CO2 from the atmosphere to the ocean – which could conceivably have triggered the huge volume of carbonate deposition in the Carboniferous.

One might also speculate that the co-incidence of low global temperatures, and exceedingly low atmospheric CO2 levels in the Carboniferous and Pleistocene- Holocene are and the climate being unstable on a 100 ky time scale because it is sensitive to minor variations in solar and/or orbital/rotational influences when atmospheric CO2 concentration is very low and there is a Paleogeographic configuration which places a continental land mass in polar latitudes.

The above synthesis has implications for the contemporary rise in atmospheric CO2 concentration which deserves to be further investigated especially as the anthropogenic emissions of CO2 are such a small proportion of the combined annual Ocean – atmosphere-biosphere fluxes and as so little data is available about the volume of CO2 emissions by volcanism – and especially mid ocean ridge submarine volcanism.

RR,

All he was saying is that there is a poorly-understood CO2 limestone cycle in the oceans, which like the ice-caps, adjust to the prevalent conditions. There are loads of earth processes we are only marginally aware of, and have no modelling capability with.

TBYJ
Is your calculation for the effects of CO2 planet independent? Using data from NASA there would appear to be roughly 10x as much CO2 in the atmosphere of Mars as Earth. Mars doesn't have the complications of water, volcanoes and various other natural processes to complicate the issue.

I wondered if the calculation, when done for Mars, produces decent results. I'm not too worried if you haven't done the calculation or don't have references I'm only curious rather than desperate to know.

TBYJ
PS.
I understand the Inverse Square Law for energy arriving at Mars having implecations

I hadn't realised that this thread was running when I posted this (slightly modified) on one of the normal blog discussions:

"The IPCC allows that various gases in the atmosphere are greenhouse gases - but excludes oxygen for a reason I don't understand. Since oxygen is like all other gases in the classical physics description of a gas, it has it's own partial pressure, thermal capacity, etc. In short, it follows the gas law formula we all know PV=RT (taking P and V in this case to be the partial pressures for each gas molecule).

CO2 is also in that pile, doing its bit as a classical gas molecule. And because these atmosphere gas molecules can absorb and conduct heat, they add to the heat-loss process from the earth's surface and effectively lift the energy balance point (the point at which incoming, blackbody radiation from the sun balances the blackbody radiation from the earth) away from the earth's surface. The surface has become warmer: thus, your greenhouse effect.

But CO2 (and other molecules) has a quantum mechanical gimmic which says it can absorb/trap energy. When that happens, the CO2 molecule absorbs a precise quanta of energy and uses this to change the pattern of the valence bonds of the molecule. If it hadn't done this, the molecule would have simply undergone a usual energy exchange collision which would have contributed to the thermal agitation of that molecule. But in the quantum absorbing/trapping case, the energy has gone into a different sink. The molecule 'temperature' has not changed. Effectively, that molecule has cooled the atmosphere! (Incidentally, it's exactly this trapping/ release process that underpins semiconductor theory).

Now of course, the energy traps involved here are quite shallow compared to the energy of thermal agitation and thus thermal agitation causes release the quantum absorbtion energy very quickly; at that point, the valence bonds flick back into their normal state, the thermal energy apparently reappears, and the whole thermal agitation/conduction that takes place in the atmosphere continues. It means that photons with energy the same as the trap depth of CO2 molecules have reduced chance of escaping from the earth, (at a frequency determined from the equation f=h/Et where h is Plank's constant and Et is the trap depth) but what the CO2 molecule has done during the trapping process is to lower the quantum energy of some photons by dividng it between trapping and thermnal agitation.

So how on earth does this CO2 quantum trapping contribute to the greenhouse effect and thus make CO2 a special molecule.? (The same observations would apply to H2O and CH4).

Capell, there's nothing that special about CO2. The point is that although CO2 (and H2O et al) can do this "gimmick" (as you call it) - the majority of the atmosphere cannot - diatomics don't absorb at the wavelengths that correspond to air temperature.

I'm not quite sure what your point is. You describe CO2 asymmetric bond absorption of IR.. which is correct.. and then ask the non-sequitur about how does it contribute to the GHE. That IS the GHE.

TBYJ
I appreciate there are few of the atmospheric molecules that display trapping.

The bond trapping of CO2, H2O and CH4 are not the entire greenhouse effect. The simple fact that the atmosphere exists plays the majority role in raising the earth surface temperature by 33 C. And that effect is explained entirely by the classical gas laws.

Photon collisions (if you like, rather than discuss thermal agitation collisions of particles) set the temperatrure of each layer of the atmosphere.

The trapping phenomena appears to do two things:
when trapped, the trap energy disappears as far as far as thermal agitation is concerned; the energy goes into the valence bonds.
when trap energy is released, the thermal photon reappears and once more embarks on its normal thermal agitation process or is re-trapped. The effect on the black body spectrum of this process will be to shift the blackbody radiation spectrum towards that of a cooler body.

To calculate the effect of CO2 now requires some very complicated maths and physics including trap capture cross sections, thermal path direction and the like. I suppose some very clever people have worked out that this amounts to a warming effect.

The bond trapping of CO2, H2O and CH4 are not the entire greenhouse effect. The simple fact that the atmosphere exists plays the majority role in raising the earth surface temperature by 33 C. And that effect is explained entirely by the classical gas laws.

And so the madness continues.