rhoda

they have been going on since 1979.

http://www.metoffice.gov.uk/hadobs/hadat/images/update_images/tropical_upper_air.png

Well, part of the problem is it's difficult to measure a 'flux' - you can only measure whatever is fluxing, in this case IR radiation in the LW bands. These are actual measurements of IR (or radiated heat as you might call it) coming out of the top of the atmosphere so is as close as you're going to get to measuring the thing you want.

From that graph, the troposphere appears to be getting slightly hotter, and the stratosphere slightly colder. Is this a tropospheric 'hot spot' ? I don't know, but you said it wasn't worrying you, so we'll leave that there :)

In any case, I included it not to raise any points about the graphs, just to satisfy you that the measurements are being taken, as you seemed to be implying that we weren't measuring these things, presumably for some nefarious reason.

I'll try to answer Dung and rhoda in a single reply:

Dung:

The reason those two are not lab proven is because they are effects in the atmosphere. You can prove the specific case in the lab and generalise it to the atmosphere:

Point 1: If you excite molecules of a GHG in the lab by shining LW into them, the photons which are re-emitted are omnidirectional. This had been observed in the lab. If you believe the GHG in the atmosphere would behave differently, for example, only re-emitting photons upwards against gravity, then please state the mechanism by which you think this would happen.

Point 2: If you shine LW radiation at everyday solids, such as soil, stone, liquid water, ice, organic material, then they heat up. This is proved both in the lab and every time you switch an electric fire on. It can be observed at night when clouds come in on a formerly clear night. The air heats up. If you had were measuring the temperature of the solid objects on the ground you would see them heat up over time. Where do you propose the heat is coming from?

Point 3: CO2 emissions are going up, and average temperatures appear to have stopped rising. This does not mean that my simplistic model of how the GHE works is wrong. It just means that temperature is not ONLY driven by the GHE. A temperature rise is a RESULT of the GHE, it's not the effect itself. If something else is also acting on the temperature, such as clouds reducing insolation, then the GHE is still going full tilt, it's still a real and measurable effect, but the temperature can be going down, if the other effect is large enough to counteract it. This is the real nub of the skeptic position - that the GHE is not the only vector acting on temperature.

Point 4: Yes, CO2 is a trace gas, and is not the dominant GH gas, and although it is only 0.039% of the atmosphere, it provides 24% of the warming effect. This is because only GHGs can provide a warming effect (for the emission/absorption reasons stated above) and H2O takes the lion's share. It's particularly good, punch for punch, at absorbing LW in the appropriate bands. The bulk of the atmosphere O2 and N2 are unable to get involved in the IR photon exchange. We do not control the amount of H2O in the atmosphere, that's part of the hydrologic cycle. So the only thing that matters is the amount of CO2, not the ratio of CO2 to O2/N2 since they do not take part (except to hold heat energy) The 'trace' argument is always a red herring.

rhoda,

A state change will use up some energy, through latent heat, but it doesn't use it all. What happens is you get a slightly lower temperature and more water vapour. You need to remember that evaporation can only happen near the surface of water and varies by local humidity and temperature, so there are constraints on the rate of evaporation which would limit it. I have to admit we're straying into an area I'm less sure on - the hydrological aspects of climate - but then Im in good company since it's possibly the least well understood part of it generally.

Evaporation rates are a fiendishly difficult thing to measure. It's made worse when we consider some of it is sublimation from ice. At the moment it's measured by satellite (using spectrographic analysis of H2O absorption, I believe)

Here's a graphic: http://www.srh.noaa.gov/jetstream/atmos/images/max_evap.jpg

Here's one showing the supposed 'change' over time http://oaflux.whoi.edu/images_flux/Evp-salinity.png

Again, I'm not going to comment on what they show, arguing for or against them is beyond my level of understanding, but again just to show that these things are being measured.

Your final point is another expression of what you've been positing all the way through - that the effects described by the GHE are not being measured, the implications being that they are being either negligent or downright corrupt.

We're on the same side, there are some serious shenanigans going on in some parts of the science. We all know that. But let's concentrate on hitting them where the problems actually are. We waste FAR too much time and energy arguing against the GHE which is not seriously disputed anywhere, which is why they can dismiss us as ignorant savages.

The good news is, by focussing on the scale of the effect of the GHE you've now arrived at where I believe proper scientific skepticism lives. Welcome to being a Lukewarmer, hated by all sides, but probably destined to be the one who was right all along!

Here are the three sides of the argument defined in terms of where we are now.

0. Common Ground - the GHE causes the earth to be warmer than it would be due to the effects of an atmosphere. This is due to the existence of GHGs which can absorb and re-emit IR raditation, which slows down the rate at which the earth loses energy. As it is losing less energy than it is gaining from the sun, the earth and atmosphere warm. As they warm, the quantity and energy of the photons they emit increases until the temperature reaches a point where enough photons are getting out of the atmosphere to balance the energy budget. This makes the earth 33K warmer than it would be without an atmosphere.

1. Pro CAGW - Increases in atmospheric GHG increase the GHE and cause the earth and atmosphere to be warmer, which releases more water vapour by evaporation, increasing the GHGs in the atmosphere, amplifying the effect. Melting of prehistoric ice also allows outgassing of trapped methane, another GHG, further amplifying the effect. These factors may cause 6-10 degrees of warming.

2. Lukewarmer position - Increases in atmospheric GHG increase the GHE and cause the earth and atmosphere to be warmer. The amount of warming predicted by just this mechanism is around ~ 1 degree. Lukewarmers do not believe in the amplification effects of extra water or outgassing, or believe that these effects are counterbalanced by as yet poorly modelled 'dampening' negative feedbacks, such as condensation mechanisms (clouds) increasing the albedo of the earth, reducing insolation, and thus temperature. Lukewarmers are skeptical about data quality and manipulation.

3. Hardline 'Skeptic' position - or what the other side call 'deniers', do not accept the Common Ground principles about the GHE mechanism, and either believe it doesn't exist at all, or believe in various alternative 'Slayer' theories, such as pressure driven temperature etc. Hardline skeptics also doubt the veracity of current data quality and manipulation, and often extrapolate that into conspiracy theory, muddying the scientific arguments with political ones.

A lot of people move between these three. I started as a 1, true believer. Over time I got suspicious. I read the Bish's HSI and became a 3, doubting the whole lot of crooks. Then by reading and talking to people, I saw that not all of the science was bad, and drifted into 2. I could go either way again, it depends on the evidence.

It's not a long chain of conjecture, it's based on 2 simple measurements -

(1) the amount of energy absorbed by the TOA (less albedo) as measured by satellite.
(2) the temperature of the earth as measured by thermometers.

From (1) you can work out what the temperature would be without an atmosphere. Then subtract from (2) to get the effect of an atmosphere = 33K

You can do that at the average level, to get a course unrealistic figure (33k) or you can grid up the temperature readings into small areas and apply the rule based on an a double integral of angle and magnitude of insolation, to give you a much better idea on a regional basis how much heating there is.

All that stuff about longwave IR, photons, convection etc, what you would call the long chain of conjecture, is an attempt to model WHY the atmosphere is able to do that 33K. Not the actual amount itself, which comes from two simple measurements and a long-established physics equation. No serious minded person (even the Slayers) doubt that is DOES warm us.

The only thing I got out of the Nikolov & Zeller paper was that the calc for (1) was done incorrectly by the IPCC and treated the earth like a flat disc. This is not a new claim, I remember people pointing out the 'flat earth' model the IPCC used many years ago, and the response at the time was to say that the summary used it, but the detailed GCMs don't. Even if they are right, and they underestimated the GHE that surely makes it worse for those who doubt it exists?

rhoda, I spend a lot of time answering your questions, it's fun, I like science. You come up with points and questions, such as 'do we measure this?' I show you we do. Then you ask some more questions which I try to answer, and it seems to do to your satisfaction because you can find no flaws or further details to ask. You move your area of doubt or inquiry onto another topic, each time I have in answering, moved you slightly towards what I would call a scientific position, i.e. not doubting what is basic undisputed physics but trying to concentrate on the areas where there is most uncertainty and disagreement.

This makes it most galling and heartbreaking, when at the end of such a discourse, where I feel as if I've been countering your perfectly reasonable questions with perfectly rational answers, that you seem to reflexively revert back to an attitude of disbelief, not based on the things we've been discussing or the logical path that the facts I've been presenting take you, but purely on a feeling that it must be wrong or corrupt. It's fine to feel that way, but at least admit you arrived at it not by an examination of the facts, but by intuition.

rhoda, BigYin, et al,

I am not sure where to enter this discussion, which is very interesting. I thought it might be best to post on Richard Drake's new thread, but if the discussion of this subject is going to continue here, I am re-posting. Please say where would be best.

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I am planning to write a short essay, entitled "The Three Pillars of Deception", which will be a simple rebuttal of the CAGW hypothesis. The three pillars are: fiddled data, useless models and flawed physics. While the first two subjects are relatively easy to demonstrate, with ample evidence of hockey sticks and failed predictions, the third is not. My original intention to go with "back radiation" evoked howls of "slayers" and "skydragons", and other such nonsense, and is clearly neither understandable nor accepted. I would therefore appreciate comments and suggestions on the following alternative:

"The CAGW hypothesis is predicated on a "greenhouse effect" (GHE) in which the Earth's atmosphere raises the surface temperature of the planet by 33 degrees Kelvin above that of an airless planet, and that anthropogenic emissions of carbon dioxide will increase the surface temperature by a dangerous amount - 2 degrees or more. This is hopelessly flawed physics, partly due to incorrect mathematics (not using Holder's inequality) and partly due to the confusion between diurnal thermal equilibrium and thermodynamic equilibrium. The fact that the physics is flawed is simply evidenced by spacecraft measurements of the surface temperature of the Moon - an airless world of the same composition and insolation as the Earth."

Roger, a couple of comments:

'Greenhouse Theory' is the description of a mechanism, not the calculation of a temperature figure.

'Greenhouse Theory doesn't predicate 33K, it only states that an atmosphere containing GH gases would be warmer than one without it.

The measure of 33K is based on

1. Energy Budget theory (for a body in thermal equilibrium, energy absorbed = energy emitted)
2. Stefan-Boltzmann relationship (black body emits energy proportional to the 4th power of its temp)

And yes, that figure may be incorrect due to incorrect application of Holder's Inequality when modelling the energy budget across a sphere. Using the correct technique puts the figure somewhat higher than this at around 155K. This does not invalidate 'greenhouse theory' just demonstrates the Energy Budget calculation was done incorrectly, and in fact weakens the case that the GHE does not exist.

'Greenhouse Theory' further does not attach the value judgement 'dangerous' to any calculated result, that's left to people interpreting the results.

I have no comment on the claim that "Greenhouse Theory confuses diurnal thermal equilibrium and thermodynamic equilibrium" since I don't know what the difference is, or why the word 'diurnal' makes any difference whatsoever. Perhaps you could explain why a symmetrically spinning planet, with equal parts moving into and out of shadow at any time, makes any difference to the energy absorbed and emitted?

Roger,

I've read the N&Z work and I fully understand their suggestion that a full integration over the surface area of a sphere needs to be done accurately to estimate an average grey body temperature. What I can't find are any measurements of 'average' lunar temperature that backs up their calculation. From the various sources I've found on the web (admittedly not a thorough search) the average surface temperature of the moon is something in the region of 250K. Subsurface temperatures (at ca. 1m depth are not subject to diurnal variations and are about 240K. I don't know how representative these are of the whole satellite.

I suspect that the figure of 154.3K that N&Z refer to as the observed surface temperature of the moon is in fact the value they calculate from their version of the S-B equation.

Note also that diurnal effects on the moon will be significantly greater than on Earth where the lunar day and night are close to 14 days each as opposed to just 12 hours on Earth.

Other than this I fully support TBYJ's comments. The N&Z theory is simply wrong!

Thanks BigYin,

We agree on Holder's Inequality. Your earlier statement "the response at the time was to say that the summary used it, but the detailed GCMs don't" is something that I did not know, as GCM mechanisms seem to be coulded by smoke and mirrors.

I accept that this "in fact weakens the case that the GHE does not exist", but that was not my point - which was that their calculations were downright wrong. I think we should be careful with terms like GHE, because it maeans different things to different people (for examle, N&Z think that GHE refers to an effect reliant only upon the mass of the atmosphere and insolation, regardless of chemical composition).

By diurnal thermal equilibrium I was referring to that fact that surface temperatures on Earth are stable, at least over a period of a few days, whereas thermodynamic equilibrium is something entirely different. The surface of the Earth is never in thermodynamic equilibrium due to planetary rotation, and there are differences between equilibriun and non-equilibrium thermodynamics. I suspect that GCM calculations are based upon thermodynamic equilibrium with a purely radiative forcing for CO2 added - in other words garunteed to produce warming - but I am not sure.

"Perhaps you could explain why a symmetrically spinning planet, with equal parts moving into and out of shadow at any time, makes any difference to the energy absorbed and emitted?" Well, the planet is not symmetric and the parts are not equal. Averages do not cut it, due to the fourth power of the SB equation.

As you can see, I am struggling to find a "simple explanation", but your comments are most welcome.

Thanks for the reply Paul,

I'll dig out the lunar data that I think refutes NASA's original statements (this may take time, as I think it is on Tallbloke's blog).

I don't buy all of the N&Z stuff (I am not convinced by their conjecture that albedo is an effect of pressure driven temperatures), however, you must admit that their correlation of pressure to temperature for about 10 planetary bodies is impressive. And you must admit that they were right about Hoder's Inequality, and the IPCC was wrong. The question is - is all of the IPCC physics wrong?

Paul, to be fair to N&Z I don't understand enough of their paper to definitively declare it bankrupt, but it fails a few "smell tests" for me.

It seems to comprise of one surprising coup about the flat disc vs sphere argument, and then hung off the back of it

1. a rather uncompelling rehashing of a theory which has been around for ages, namely that gravity induced pressure means that air molecules being closer together due to this pressure provide increased opportunity for convective heat transfer from a surface warmed by insolation. Thus the lapse rate can be explained by this mechanism and not GHE.

It fails the smell test though - why does it get immediately (i.e. not convectively) warmer when clouds come in over a clear sky? If the temperature gradient was defined purely by pressure and not the radiative properties of what is in the atmosphere, then it would make no difference.

2. a clever yet mathematically disengenious piece of curve fitting. One the the equations requires seven parameters to match seven data points. I'm not a physicist, I'm an engineer, and curve fitting was an entire module of my mathematics undergraduate course. Von Neumann once said "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk."

There are one or two polemical statements in the paper which smell bad too.

Well, the planet is not symmetric and the parts are not equal. Averages do not cut it, due to the fourth power of the SB equation.

This is a rather remarkable thing to say. I think you'll find if the planet was not symmetrical, it would be a thin disc of dust and gas going round the sun by now. The parts moving into sunlight and the parts moving out of sunlight have EXACTLY the same area (give or take terrain differences). It is also rotationally symmetric, in that each part of the earth goes through the same (diurnal) pattern of insolation, so over many diurnal cycles, each part gets the same insolation and undergoes an identical heating and cooling profile, so the rotation can be ignored as a factor. It's common sense - if diurnal effects caused an imbalance, we would be getting hotter or colder every day.

The 4th power of the SB equation is a geometrical mistake and only matters when considering averages across an spherical area in roughly parallel insolation. I think you're reading too much into this mistake than is actually there, it has nothing to do with time-dependent calculations such as diurnal rotation. The averaging of SB is a mistake only because they used the wrong shape, nothing to do with rotation.

When considering the earth as a disc, every part of the disc is equally insolated, so you can simply divide by area to get a value of flux. With a sphere, only small circle directly closest to the sun gets full insolation, weakening off at a known rate (by a cosine ratio) until the poles get zero. To work out the actual temperature, you have to work out insolation values left and right and up and down. You then sum them. Luckjily maths has a handy way of summing infinitesimally small bits - integration. This double integration correctly attributes the insolation in the correct amounts to each part of the earth, and each part of the earth then gets its own temperature, which is then averaged. In effect we're just doing lots of little energy calcs and summing them, which we agree gives a better answer than treating the earth as a flat equally illuminated disc - the GHE is bigger than previously thought!

N&Z claim that all back-radiation is swamped by extra convection so can be ignored. Easily refuted? I'm glad you agree.

BigYin,

http://tallbloke.files.wordpress.com/2011/12/unified_theory_of_climate_poster_nikolov_zeller.pdf

Equation 7 gives the atmospheric enhancement enhancement (ATE) SOLELY as a funtion of surface pressure for 8 planets. Well, it impresses me.

" if diurnal effects caused an imbalance, we would be getting hotter or colder every day" Yep - seasons. The northern and southern hemispheres are not symmetric, and the Earh's axis is tilted to the ecliptic

TBYJ, Roger,

For me the statement that pressure controls molecular kinetic energy and therefore temperature which is explicit in the note at tallbloke's site shows such a profound misunderstanding of simple kinetic theory of gases that my jaw dropped. I missed your point that they postulate that the increased pressure means that there is increased heat transport via convection. I'll need to go back and check. Of course they still require a radiatively active atmosphere in order for the heat carried aloft by convection to be lost to space. Accepting this then we are back with the 'GHE' as we understand it!

As regards the curve fitting I'm in full agreement with you TBYJ. Superficially it looks impressive. It should be possible to determine the functional form of the relationship between pressure and temperature and see how well this fits the data.

I was also unimpressed by the supposed pressure changes in Earth's atmosphere through geologic time. This fails the smell test for me.

Of course the integration over a spherical surface is interesting but not new. I'm piqued enough to want to check their equations and result.

Roger,

" if diurnal effects caused an imbalance, we would be getting hotter or colder every day" Yep - seasons. The northern and southern hemispheres are not symmetric, and the Earh's axis is tilted to the ecliptic

You are referring to annual seasonal changes, not diurnal. Yes, over the course of a year the amount of insolation a single point of earth receives varies, but this change itself is completely symmetrical in time, in exactly the same way as the diurnal cycle of day and night is symmetric in time.

Year after year, the changes caused by the earth's tilt to the ecliptic are identical, and do no increase or decrease, therefore there is no imbalance - year after year, a single point on the earth receives an identical profile of insolation, so the time component can be ignored over a period of years, you can average it, because the 4th power rule does not apply to time, only to geometry.

Again it's common sense - if there was an imbalance (asymmetry) caused by the tilt of the earth, we would be getting increasingly hotter or colder on a yearly basis, and would be slag or an iceball by now.

Equation 7 gives the atmospheric enhancement enhancement (ATE) SOLELY as a function of surface pressure for 8 planets. Well, it impresses me.

That's because it's mathematical sleight-of-hand. You say it gives the atmospheric enhancement SOLELY as a function of surface pressure for 8 planets. But it's not SOLELY, is it? There are other things in that equation.

Do you see the two co-efficients, and two exponents....? those large multi decimal place numbers that sit there with no explanation of what they represent? It gets worse, it's actually Eqn 8 which gives the temps, and as well as using the 4 variables here, it introduces 3 more of its own. What sort of natural law requires a variable per data point?

That SOLELY isn't looking so impressive now is it?

It could be they have stumbled on a new physical law, it could be that they've just managed to create a curve which happens to go through those 8 data points by careful use of random (or in the case or curve fitting, calculated) additives, multipliers and exponents.

Well I have dipped in and out this thread, but never contributed - never thought I had anything useful to contribute. Perhaps I still don't but there it is.

One or two simple observations though.

The IPCC was effectively tasked at the beginning with testing GHE theory and despite us spending billions on Climate Research it never has. They just assumed they knew and have modelled accordingly ever since. Recent papers have shown that even the radiative balance that they all use is probably off by considerably more than any of the "rises" they claim to model.

I notice TBYJ quotes that 24% of the GHE comes from CO2 - that is the biggest % I have ever seen quoted anywhere. 10% seems popular and given the narrow absorption bands, more likely - and I think even warmists believe CO2 suffers from the law of diminishing returns. I am not sure on where I stand on the subject of a saturated GHE as postulated by some. The fact that cloud cover has decreased by a small % steadily during satellite era (and increasing CO2) could be less available water vapour and obviously more isolation. But of course the science is settled!!! Sceptics can't even agree how unsettled it is.

I have always believed in the GHE since I first sat in a classroom half a century ago and heard about it. BUT in recent years I have been exercised to think more carefully before dismissing "Slayers" out of hand - because most of those who do dismiss them are people in academia or who sit in chairs blogging (like me). And some of the Slayers are scientific engineers whose grasp of the heat transfers in question (and their measurement) have been life or death for astronauts in the space programmes. There is no doubt that as some Slayers point out many people do confuse incident radiation measurements with temperatures measured in a screen. What is the real temperature at TOA.? What is it we are measuring?

Hope you can help me.