Entropic, thanks for the compliment: it is most welcome. Yes I am familiar with the two negative feedbacks you mention although I consider them only as obvious occurrences to a changing CO2 concentration in a gravitational field. I understand why you would name them negative though.

I am also aware of the convection process and its net effect. Where we might differ is on the energy in the atmosphere (if I have understood you correctly). I see that as being imparted by the cooling flow to space exciting radiative molecules on the way and they in turn distributing that throughout by collision. There is no doubt that that occurs and the conclusion that there is a greenhouse effect without there being an energy imbalance at TOA makes sense to me.

However, atmospheric physics is a bit of an esoteric subject. My only interest in it is to wonder if it is being correctly applied in the search for a true measure of GE with all its political baggage. Currently I doubt very much that it is.
_____________

RR. Thanks! My favourite question of climateers is just that: how does Global Warming theory explain the coming cooling trend but then add - or is that an impossibility? I get few answers.
We shall wait and see.

ssat

Lets try a thought experiment.

Imagine two enormous balloons, floating in Earth orbit in sunlight. Both are transparant to visible and longwave radiation.

In the centre of each balloon a smaller black balloon is anchored to act as an energy absorber mimicking Earth,s surface

Balloon A contains air of normal composition, including greenhouse gases. Balloon B contains a nitrogen/oxygen mix at the same pressure, without greenhouse gases.

The effects of gravity, including pressure gradient and convection, has been removed.

Which balloonwill be warmer? What will the temperature gradient between the centre and surface of each balloon look like?

Other readers might care to comment.

EM. You wrote that you could see no way in which heat radiating as longwave radiation outward into [= towards] space is doing work. What about my heated hand, Martin A's IR dectector, and chemical changes occurring in an IR sensitive photographic film, are these not changes being made by the longwave radiation as it is locally intercepted on its way to space. Are such changes not reflections of work being done.

A thermodynamic definition of Work is, "the energy transferred from one system to another by macroscopic forces". Only if you conceive the solar energy system within the whole Earth as an entity could you conclude no additional work can be done. But this is a useless viewpoint. More important (to my argument) is that work can be done within the system so long as in the wider environment energy is discipated. Otherwise you have to be able to explain why some IR fluxes do work, whereas that in the Earth's atmosphere does not and somehow cannot.

I haven't yet thought it through yet but it seems to me that the whole process of longwave radiation upward through the atmosphere and into space fits the thermodynamic definition of work being done.

Ravishing Rattie
"my compliments can be somewhat backhanded".
Don't I know it!
"there are times when I rely on people not actually reading what I wrote".
Don't I know it!

Come on Entropic! The post you complimented me on addressed this. The energy in the atmosphere is the instantaneous OLR with radiative gasses present. The pressure gradient due to gravity is also a density gradient. The density gradient is pretty much the lapse rate which is the temperature gradient, the lapse rate gives the GE as a quantity greater than the S-B temperature. I'm sure you would want to put me out of my misery so just pop the black balloon to reveal the answer written on a piece of paper in my handwriting :)

Ssat

I am also aware of the convection process and its net effect. Where we might differ is on the energy in the atmosphere (if I have understood you correctly). I see that as being imparted by the cooling flow to space exciting radiative molecules on the way and they in turn distributing that throughout by collision. There is no doubt that that occurs and the conclusion that there is a greenhouse effect without there being an energy imbalance at TOA makes sense to me.

CO2 molecules play "pass-the-parcel" with longwave photons, gaining energy with each excitation and losing it with each emission. This could be regarded as doing work. At the top of the atmosphere the last CO2 molecule radiates it's photon to space and that photon does no further work in the climate system. It is a valid argument, but rather pedantic.

Under constant conditions of insolation, albedo and CO2 the system should settle to a constant temperature. There should then be no energy imbalance because there is no net gain or loss of energy.

An energy imbalance should only occur when the system is changing. My view, typical of the consensus (shut up, GC :-) ) , is that increasing CO2 has created an imbalance by reducing outward radiation. The result is that the system is gradually taking up heat. Because the CO2 concentration continues to increase, the heating effect lags behind. The imbalance will continue until CO2 becomes constant and the heating effect catches up, then the imbalance will disappear.

You seem confident that cooling is coming. For that to happen the imbalance would need to reverse, with outward radiation exceeding insolation. The basic equation for a stable temperature is is that insolation-albedo=outward radiation.

Are you expecting a decrease in insolation, an increase in albedo, an increase in outward radiation or some combination? What physical processes would be involved?

Entropic, forget the 'doing work' thing - that was not in my original post.

I am not expecting but can see a decrease in insolation as the solar cycle currently suggests there might be. There would be other effects of that. What I see from past records are varying average temperatures and on that basis expect that to continue. I don't see the variation as linked particularly strongly with CO2 alone nor do I know if one leads the other or vice versa.

We've had Trenberth saying a pause of 17 years would be the end of the theory but then claim that the heat is hiding. My question is more about what would finally be accepted as the nail in the coffin.

So sorry ssat but your statement "Because outgoing radiation is the cooling flow to space and which can do no work" was indeed within your original post (Nov. 25, 6.12pm). I challenged you about it and quoted your assertion at 6.48pm.

Ravishing Rattie. Stand in the urban canyons of a city like Houston and feel the radiated heat in the early evenings and you would agree with me that these IR fluxes are quite noticeable and do considerable work.

Ssat

Don't link pressure, density and temperature a priori. They interact through the Ideal Gas Law ( PV=nRT) but once they stabilise there is no particular reason why higher pressure or density should be warmer.

Consider a bicycle tyre lightly inflated. it will be at ambient temperature.When you then pump up the tyre you increase the pressure and density of the air inside. The work you do to increase the pressure and the density ends up as heat increasing the temperature of the air (and the pump). The heat then disperses and the temperature of the air in the tyre returns to the ambient temperature of its surroundings. Despite the increase in pressure and density there is no lasting increase in temperature.

Imagine Earth with a nitrogen, oxygen atmosphere. Ignore the day/night cycle for the moment. There will be a pressure and density gradient due to gravity, but no temperature gradient. Energy is absorbed from shortwave radiation at the surface and reradiated as longwave radiation at the surface. The surface stabilises at the black body temperature.The atmosphere warms by conduction from the surface, but does not lose heat to space, so it stabilises at the same temperature throughout, with no temperature gradient so there is no convection, except as latudinal variation creates a global circulation like a single Hadley cell.

Now add greenhouse gases. The atmosphere gains heat at the surface and loses heat at the top. This creates a temperature gradient and with it convection. Once you have convection you have masses of air rising and reducing pressure, or sinking and gaining pressure.. From that you get the lapse rate.

Balloon A will warm to the black body temperature and stabilise with the centre at the black body temperature. There will be no temperature gradient between centre and surface.

Balloon B will be warmer at the centre than Balloon A due to some redirection of outgoing longwave radiation. Since the outer surface of the balloon is losing longwave radiation there will also be a temperature gradient, warmer at the centre and cooler at the outer surface. Heat will be transferred by diffusion from the centre outwards.

Even in the absence of gravity, convection or a pressure/density gradient a balloon with greenhouse gases will show a greenhouse effect, while a balloon without greenhouse gases will not.

Ssat

The pause has ended with three successive record warm years, at a time when the Sun is well into the downslope of the weakest cycle in decades. Without an El Nino ext year's temperatures will probably be closer to the long term trend, anomaly 0.8C or so. Forget the pause, if it ever existed it is over.

Trenberth's missing heat was found, accumulating as ocean heat content.

You may have a long wait for a solar induced cooling trend to kick in.If you do the numbers, even a full Grand Minimum would only lose a fraction of a degree, not enough to cancel AGW.

Ssat

I thought for one horrible moment that you were expecting gravity to change! :-)

Radical Rodent 7:00pm, cont) ........ and more to the point, no one has actually noticed it getting any warmer.

I think the total lack of real evidence is why Trump has decided to end the computer enhanced delusions generated by climate science.

If only climate science hadn't decided ECS could not have been lower than 1.5. If ECS is 0.0-1.0 it would make more sense of climate nonscience.

RR, he's not so keen on the balloon datasets, though, because they agree with the satellites.

Trenberth's missing heat was found in the error bars. Climate-alarm "scientists" just love uncertainty when it can encompass their failed predictions.

michael hart & Radical Rodent

US Greens are trying to fund a recount in certain United States amid claims that THEY robbed Clinton of the win that it was presumed was hers. UK Remoaners are still trying to reverse BREXIT . Climate Science can, no doubt assist with the statistics of recalculating/recounting anything, no matter how old or non existent the actual data is, but they still can't reveal who decided CO2 caused Global Warming, let alone why or when.

Ravishing Rattie. There's a world of difference between cannot do work and doesn't do (much) work. However, the transfer of long wavelength energy from the Earth's surface to space doesn't just happen. Transfer of energy from one place to another involves doing thermodynamic work. Since the amount of energy is more or less equivalent to the total amount of the Sun's energy that reached the surface, that's an awful lot of work being done.