In On Having a Laugh – by Gerlich and Tscheuschner (2009) I commented that I had only got to page 50 and there were 115 pages in total.
Because there were so many errors already spotted, none central to the argument (the argument hadn’t started even at page 50), it seemed a pointless exercise to read it further. After all, many interesting papers await, on the thermohaline circulation, on models, on stratospheric cooling..
Perhaps most important of the criticisms was that Gerlich and Tscheuschner didn’t appear at all familiar with the climate science they were “debunking” – instead of commenting on encyclopedia references or throwaway comments in introductions to works unrelated to proving the inappropriately-named “greenhouse effect” they should be commenting on papers like Climate Modeling through Radiative-Convective Models by Ramanathan and Coakley (1978).
Clearly they were “having a laugh”
However, after noticing that a recent commenter actually cited Gerlich and Tscheuschner I went back and reviewed their paper. And in doing so I realized that many many misinformed comments by enthusiastic people on other popular blogs, and also this one, were included in the ground-breaking On Falsification Of The Atmospheric CO2 Greenhouse Effects by Gerlich and Tscheuschner.
It’s possible that rather than enthusiastic commenters obtaining misinformation from our duo that instead our duo have combined a knowledge of theoretical thermodynamics with climate science that they themselves obtained from blogs. The question of precedence is left as an exercise for the interested reader.
Miseducation
It is hard to know where to start with this paper because there is no logical flow.
Conductivity
The paper begins by reviewing the conductivity of various gases.
It is obvious that a doubling of the concentration of the trace gas CO2, whose thermal conductivity is approximately one half than that of nitrogen and oxygen, does change the thermal conductivity at the most by 0.03% and the isochoric thermal diffusivity at the most by 0.07 %. These numbers lie within the range of the measuring inaccuracy and other uncertainties such as rounding errors and therefore have no significance at all.
Clearly conductivity is the least important of means of heat transfer in the atmosphere. Radiation, convection and latent heat all get a decent treatment in studies of energy balance in the atmosphere.
If our duo had even read one book on atmospheric physics, or one central paper they would be aware of it.
Uninformed people might conclude from this exciting development that they have already demonstrated something of importance rather than just agreeing wholeheartedly with the work of atmospheric physicists.
Pseudo-Explanations to be Revealed in Part Two? Or Left as an Exercise for the Interested Student?
Following some demonstrations of their familiarity with mathematics and especially integration, they provide three conclusions, one of which refers to the Stefan-Boltzmann law, j=σT4:
The constant appearing in the T4 law is not a universal constant of physics. It strongly depends on the particular geometry of the problem considered.
and finish with (p21):
Many pseudo-explanations in the context of global climatology are already falsified by these three fundamental observations of mathematical physics.
Unfortunately they don’t explain which ones. The climate science world waits with baited breath..
The footnote to their comment on Stefan-Boltzmann:
For instance, to compute the radiative transfer in a multi-layer setup, the correct point of departure is the infinitesimal expression for the radiation intensity, not an integrated Stefan-Boltzmann expression already computed for an entirely divergent situation.
Sadly they are unfamiliar with the standard works in the field of the radiative-convective model.
Solar Energy Breakdown and A Huge Success in Miseducation
Solar Radiation Breakdown
They followed up this table with the hugely popular comment:
In any case, a larger portion of the incoming sunlight lies in the infrared range than in the visible range. In most papers discussing the supposed greenhouse effect this important fact is completely ignored.
First, a comment on the “benefit” of this miseducation – being able to separate out solar radiation from terrestrial radiation is a huge benefit in climate understanding – it allows us to measure radiation at a particular wavelength and know its source. But many people are confused and say we can’t because 50% of the solar radiation is “infrared”. Infrared means >0.7μm. Conventionally, climate scientists use “shortwave” to mean radiation < 4μm and “longwave” to mean radiation > 4μm. As less than 1% of solar radiation is >4μm this is a very useful convention. Any radiation greater than 4μm is terrestrial (to 99% accuracy).
Many uninformed people who have become miseducated are certain that much solar radiation is >4μm – possibly due to confusing infrared with longwave.
We don’t speculate on motives on this blog so I’ll just point out that Gerlich and Tscheuschner know very little about any climate science, and from this comment probably don’t even understand the inappropriately-named “greenhouse” effect.
Why? Well, what has the visibility of the radiation have to do with the “greenhouse” effect? Of course it’s ignored. Our duo are just demonstrating their ignorance of the absolute basics.
Or they have some amazing insight into how the visibility or not of solar radiation affects the radiative transfer equations. All to be shared in part two probably..
The Core Question – the Radiative Transfer Equations
After a brief explanation of Kirchoff’s law, our duo discuss the core equations, the radiative transfer equations (RTE):
LTE [local thermodynamic equilibrium] does only bear a certain significance for the radiation transport calculations, if the absorption coefficients were not dependent on the temperature, which is not the case at low temperatures. Nevertheless, in modern climate model computations, this approach is used unscrupulously.
Absorption and emission coefficients get a very thorough treatment in the numerical solutions to the RTE, however, our duo are only familiar with work around the 1900’s and skip all modern work on the subject. Perhaps a more accurate statement would be:
We have no idea what anyone does but we read somewhere that stuff wasn’t done right..
Or they could actually show what effect that dependency actually had..
Then they decide to support the RTE:
Fantastic, 50 pages in we find the real RTE. This is what atmospheric physicists use to calculate the absorption and re-emission of radiation for each layer in the atmosphere. They follow this up with:
The integrations for the separate directions are independent of one another. In particular, the ones up have nothing to do with the ones down. It cannot be overemphasized, that differential equations only allow the calculation of changes on the basis of known parameters.
The initial values (or boundary conditions) cannot be derived from the differential equations to be solved. In particular, this even holds for this simple integral.
What do they mean? Of course you need boundary conditions to solve all real-world equations.
The separate directions are independent of one another? Yes, you find that in all treatments of radiative transfer.
So Gerlich and Tscheuschner agree that the RTE can be used to solve the problem? Or not? No one can tell from the comments here. If they do, the paper should be over now with support for the inappropriately-named “greenhouse effect”, unless they demonstrate that they can solve them for the atmosphere and get a different result from everyone else.
But they don’t.
Fortunately for those interested in what our duo really know and understand – they tell us..
The Modern Solution to the RTE – or How to Miss an Important 100 Years
After surveying works from more than 100 years ago, they conclude:
Callendar and Keeling, the founders of the modern greenhouse hypothesis, recycled Arrhenius’ discussion of yesterday and the day before yesterday by perpetuating the errors of the past and adding lots of new ones.
In the 70s and 80s two developments coincided: A accelerating progress in computer technology and an emergence of two contrary policy preferences, one supporting the development of civil nuclear technology, the other supporting Green Political movements. Suddenly the CO2 issue became on-topic, and so did computer simulations of the climate. The research results have been vague ever since.
No explanation of Callendar and Keeling’s mistakes – this is left as an exercise for the interested student.
And no mention of the critical work in the 1960s and 1970s which used the radiative transfer equations and the convective structure of the atmosphere to find the currently accepted solutions.
In fact, the research results haven’t been vague at all. Regular readers of this blog will know about Ramanathan and Coakley 1978, and there are many more specific papers which find solutions to the RTE – using boundary conditions and separation of upward and downward fluxes, as wonderfully endorsed by our comedic duo.
More recent work has of course refined and improved the work of the 1960s and 1970s. And the measurements match the calculations.
But what a great way to write off a huge area of research. Show some flaws in the formative work 100 or so years ago and then skip the modern work and pretend you have demonstrated that the modern theory is wrong.
As we saw in the last section, our duo appear to support the modern equations – although they are careful not to come out and say it. Luckily, they are blissfully ignorant of modern work in the field, which all helps in the miseducation of the uninformed.
The main work of the paper should now be over, but our duo haven’t realized it. So instead they move randomly to the radiative balance concept..
Radiative Balance and Mathematical Confusion
In every introduction to atmospheric physics you find the concept of radiative balance – solar energy absorbed = terrestrial radiation emitted from the top of the atmosphere. These concepts are used to demonstrate that the atmosphere must absorb longwave (terrestrial) radiation.
This concept can be found in CO2 – An Insignificant Trace Gas? Part One
After looking at the basics of the energy balance, they comment – on the right value for albedo (or ‘1-albedo’):
In summary, the factor 0.7 will enter the equations if one assumes that a grey body absorber is a black body radiator, contrary to the laws of physics. Other choices are possible, the result is arbitrary.
Being obscure impresses the uninformed. However, the informed will know that the earth’s emissivity and absorptivity will of course be different because the solar radiation is centered on 0.5μm while the terrestrial radiation is centered on 10μm. And the emissivity (and absorptivity) around 10um is very close to 1 (typically 0.98) while around 0.5μm the absorptivity is somewhat lower.
At this point, if we were to do a parody of our duo, we would write how their physics is extremely poor and do a three page derivation of absorptivity and emissivity as a function of wavelength.
Now follows many pages of maths explaining the impossibility of working out an average temperature for the earth during which they make the following interesting comment:
While it is incorrect to determine a temperature from a given radiation intensity, one is allowed to compute an effective radiation temperature Terad from T averages representing a mean radiation emitted from the Earth and to compare it with an assumed Earth’s average temperature Tmean
What they are saying is that for energy balance if we work out the radiation emitted from the earth we have dealt with the problem.
Fortunately for our intrepid duo, they are unacquainted with any contemporary climate science so the fact that someone has already done this work can be safely ignored. Earth’s Global Energy Budget by Trenberth, Fassulo and Kiehl (2008) covers this work.
To compute these effects more exactly, we have taken the surface skin temperature from the NRA at T62 resolution and 6-hour sampling and computed the correct global mean surface radiation from (1) as 396.4 W/m2. If we instead take the daily average values, thereby removing the diurnal cycle effects, the value drops to 396.1 W/m2 or a small negative bias. However, large changes occur if we first take the global mean temperature. In that case the answer is the same for 6 hourly, daily or climatological means at 389.2 W/m2. Hence the lack of resolution of the spatial structure leads to a low bias of about 7.2 W/m2. Indeed, when we compare the surface upward radiation from reanalyses that resolve the full spatial structure the values range from 393.4 to 396.0 W/m2.
The surface emissivity is not unity except perhaps in snow and ice regions, and it tends to be lowest in sand and desert regions, thereby slightly offsetting effects of the high temperatures on longwave (LW) upwelling radiation. It also varies with spectral band (see Chédin et al. 2004 for discussion). Wilber et al. (1999) estimate the broadband water emissivity as 0.9907 and compute emissions for their best estimated surface emissivity versus unity. Differences are up to 6 W/m2 in deserts, and can exceed 1.5 W/m2 in barren areas and shrublands.
So there is potential variation of a few W/m2 depending on the approach, and Trenberth et al settles on 396 W/m2 average – at least the values can be calculated, whereas our duo decided it was computationally impossible – perhaps as they saw the problem as requiring a totally accurate GCM.
With this information, the radiative balance problem can be resolved and we can see that there is a discrepancy between the solar energy absorbed and the terrestrial radiation emitted which requires explanation. The inappropriately-named “greenhouse effect”.
Without this information we can delight in much maths and pretend that nothing can be known about anything.
Why Conduction Can be Safely Ignored and Why We Just Demonstrated It
In many climatological texts it seems to be implicated that thermal radiation does not need to be taken into account when dealing with heat conduction, which is incorrect. Rather, always the entire heat flow density q must be taken into account.. It is inadmissible to separate the radiation transfer from the heat conduction, when balances are computed..
Unfortunately, the work on even the simplest examples of heat conduction problems needs techniques of mathematical physics, which are far beyond the undergraduate level.
In fact in many texts on atmospheric physics conduction is safely ignored due to the very low value of heat conduction through gases. Strictly speaking, if we write an equation then all terms should be included, including latent heat and convection. Why just radiation and conduction?
As Ramanathan and Coakley pointed out in their 1978 paper, convection is what determines the temperature gradient of the atmosphere but solving the equations for convection is a significant problem – so the radiative convective approach is to use the known temperature profile in the lower atmosphere to solve the radiative transfer equations.
Still, no thought of conduction as that term is so insignificant – as our intrepid duo go on to realize..
Commenting on the insolubility of heat flow via conduction they take a “typical example”:
If the radius of the Moon were used as the characteristic length and typical values for the other variables, the relaxation time would be equivalent to many times the age of the universe.
Therefore, an average ground temperature (over hundreds of years) is no indicator at all that the total irradiated solar energy is emitted. If there were a difference, it would be impossible to measure it, due to the large relaxation times. At long relaxation times, the heat flow from the Earth’s core is an important factor for the long term reactions of the average ground temperature; after all, according to certain hypotheses the surfaces of the planetary bodies are supposed to have been very hot and to have cooled down. These temperature changes can never be separated experimentally from those, which were caused by solar radiation.
So heat flow by conduction is so low that achieving balance by this method will take more than the age of the universe. Therefore, it is insignificant in comparison with convection and radiation.
Good so we can move on and climate scientists are right to ignore it. Was that the point that Gerlich and Tscheuschner were making? Yes, although possibly without realizing it..
Finally, the Imaginary Second Law of Thermodynamics
In their almost concluding section we see where countless climate enthusiasts have obtained their knowledge (or the reverse).
First, here’s an extract from a contemporary work on thermodynamics. This is from Fundamentals of Heat and Mass Transfer, 6th edition (2007), by Incropera & Dewitt:
As can be seen in the text, radiation can be absorbed by a higher temperature surface from a lower temperature surface and vice versa. Of course, the net result is a heat transfer from the hotter to the cooler.
The same uncontroversial description can be found in any standard thermodynamics work, unless they consider it too unimportant to mention. Certainly, none will have a warning sign up saying “this doesn’t happen”.
The explanation of the “greenhouse effect” is that the earth’s surface warms the lower atmosphere by radiation (as well as convection and latent heat transfer). And the atmosphere in turn radiates energy in all directions – one of which is back to the earth’s surface. Believers in the imaginary second law of thermodynamics don’t think this can happen. And this is possibly due to the miseducation by our intrepid duo. Or perhaps they learnt their thermodynamics from many “climate science” blogs.
The result of the actual climate situation is that the earth’s surface is warmer than it would have been without this atmospheric radiation. Pretty simple in concept.
Here’s how Gerlich and Tscheuschner explain things:
Everyone agrees.
Now the confusion. What are they saying? This isn’t what atmospheric physicists describe. The net heat transfer is from the earth’s surface (which was warmed by the sun) to the atmosphere.
Are they saying that it is impossible for any radiation to transfer heat from the atmosphere to the earth? It would appear so –
Following their diagram above, they comment, first quoting Rahmstorf:
Some `sceptics’ state that the greenhouse effect cannot work since (according to the second law of thermodynamics) no radiative energy can be transferred from a colder body (the atmosphere) to a warmer one (the surface). However, the second law is not violated by the greenhouse effect, of course, since, during the radiative exchange, in both directions the net energy flows from the warmth to the cold.
Rahmstorf’s reference to the second law of thermodynamics is plainly wrong. The second law is a statement about heat, not about energy. Furthermore the author introduces an obscure notion of “net energy flow”. The relevant quantity is the “net heat flow”, which, of course, is the sum of the upward and the downward heat flow within a fixed system, here the atmospheric system. It is inadmissible to apply the second law for the upward and downward heat separately redefining the thermodynamic system on the fly.
Our duo first attempt to confuse, as they frequently do in their opus by claiming that a clear explanation is obscure because precise enough terms aren’t used. It’s not obscure because they make the “correction” themselves.
Then add their masterstroke. It is inadmissible to apply the second law for the upward and downward heat separately redefining the thermodynamic system on the fly.
What on earth do they mean? Our comedic duo are the ones separating the system into upward and downward heat, followed by an enthusiastic army on the internet. Everyone else considers net heat flow.
As we saw in a standard work on thermodynamics, now in its 6th edition after two or three decades in print, there is no scientific problem with radiation from a colder to a hotter body – so long as there is a higher radiation from the hotter to the colder.
At this point I wonder – should I revisit the library and scan in 20 thermodynamic works? 50? What would it take to convince those who have been miseducated by our intrepid duo?
Perhaps Gerlich and Tscheuschner can now turn their attention to all of the unscientific text books like the one shown at the start of this section..
Conclusion
There is much to admire in Gerlich and Tscheuschner’s work. It can surely become a new standard for miseducation and we can expect its deconstruction by psychologists and those who study theories of learning.
From a scientific point of view, there is less to admire.
They have no understanding of modern climate science, content to dwell on works from over 100 years ago and ignoring any modern work. They appear to believe that the basis for the “greenhouse” effect is an actual greenhouse (as was covered in On Having a Laugh) even though no serious work on the subject relies on greenhouses. (Some don’t even mention it, some mention it to point out that the atmosphere doesn’t really work like a greenhouse).
In fact, the serious work of the last few decades relies on the radiative transfer equations – equations apparently endorsed by our duo, although their comments are “obscure”.
They take many other snipes at climate science by the approach of pointing out a term or dependency has been “neglected” (for example, like conduction through the atmosphere) without showing that the neglect has a significant impact – except in the case of conduction where (unwittingly?) they appear to show that conduction should definitely be ignored!
Someone could take issue with even modern work on climate science by the fact that they ignore relativistic effects.
Within the frame of modern physics, climate science is badly flawed to ignore relativity
And after 18 pages of unnecessary re-derivation of general relativity we find that “it’s therefore impossible to calculate this and the problem is insoluble“..
Well, although they haven’t read any modern climate science, it’s hard to see how they could be so confused about the application of the 2nd law of thermodynamics.
Perhaps in their follow up work they can explain why all the thermodynamics works are wrong, and especially where this 15μm (longwave) radiation comes from:
Measured downward longwave radiation at the earth's surface
According to their interpretation of the 2nd law of thermodynamics this can’t happen. No heat can flow from the colder atmosphere to the warmer surface as that would be a “perpetuum mobile” and therefore impossible.
Where is it coming from Gerlich and Tscheuschner?
The Science of Doom 
[…] Update – new post: On the Miseducation of the Uninformed by Gerlich and Tscheuschner (2009) […]
[…] – the imaginary law also covered (possibly created by) On the Miseducation of the Uninformed by Gerlich and Tscheuschner (2009) Possibly related posts: (automatically generated)CO2 – An Insignificant Trace Gas? Part OneThe […]
I confess I haven’t gone through your post in detail, but I had much the same reaction to G&T. It sought to debunk the popular versions of greenhouse physics normally presented to the general public. Since those are all wrong, the G&T exposition isn’t doing anything very significant in knocking them down.
But the more significant issue it highlights is all those explanations out there masquerading as “the” greenhouse effect, and fooling people into thinking they understand it sufficiently to be convinced by it.
Here’s NASA:
“Certain gases in the atmosphere behave like the glass on a greenhouse, allowing sunlight to enter, but blocking heat from escaping.”
http://climate.nasa.gov/causes/
Poor old Joe Green, watches the pop-science programmes on TV, not scientifically trained but has an interest, hears about this ‘Climate Change’ and want to know a bit more. So he goes to NASA – everybody knows NASA – and gets the official explanation. He trusts it of course. He’s concerned. He’s not brilliantly happy about having to pay more, but supports the government raising taxes to do something about it, because NASA say it’s a serious problem.
Then he runs smack into a climate sceptic. Naturally, he tries to use his knowledge to help the poor deluded sceptic out. “It’s really simple,” he says, “you’d have to be an idiot not to understand it.”
And the sceptic of course slices and dices him, because he’s read up on Wood’s experiments on greenhouses, and convection, and thermodynamics, and decentered PCA, urban heat islands and Bristlecones and air conditioners and ‘adjustments’ and all the rest of it. “Here, read this,” he says over a copy of G&T.
And Joe Green is impressed. This looks like real science. He’s never heard of Ramanathan and Coakley 1978, because nobody has ever mentioned it to him. Ramanathan and Coakley 1978 does not form part of any popular exposition of anthropogenic climate change; not on the BBC, not at the Royal Society, not at NASA, probably not at the IPCC, although it’s hard to tell because the reports are so huge and unreadable that relatively few people have ever read them. No, not even in Al Gore’s Oscar-winning movie, the one they show school kids in science class. Instead, they chose to tell him about the glass on a greenhouse.
He feels annoyed, and betrayed. He’s been made a fool of. And so he goes sceptic, and you’ll have to fight twice as hard to get him back.
G&T is rubbish, and there are plenty of sceptics who know it and will say so. But it highlights a bigger problem – that the nursery-school explanations given to the public have left them uninformed and unconvinced.
The NASA explanation is rubbish too, and until scientists stop with the one-sided bashing of scepticism while staying silent on all the flaws and holes in any pro-AGW presentations, it’ll keep on getting worse. You can’t go dishing out Al Gore to people, and then when it’s challenged complain that they should really have been discussing Ramanathan.
Which is why I’m very pleased to have found your site. It does promise to give some greatly improved explanations that the intelligent layman has some hope of accessing.
Nullius in Verba,
I am a skeptic and in fact a former NASA scientist (but not a climate scientist). I do not appreciate your implication that most NASA scientists and skeptics are deluded and wrong. Both sides on this issue have several good scientists and also many wrong ones, as well as non-scientists that don’t have a clue. I personally have solid arguments as to why CAGW is not likely (but that AGW to a smaller scale is probable). I do not agree with G & H and many others, and think The Science of Doom author is very good on the science as far as he goes. Even he agrees that the real issue on the whole subject of AGW or CAGW hinges on the feedback issue, and other possible causes, which are NOT resolved. If you want to read a reasonable skeptics analysis see: http://docs.google.com/Doc?id=dnc49xz_0fb228shr&hl=en (Limitations on AGW)
I don’t recall what the HADOBS UK met office’s global mean temperature curve looked like through 2008 (the one you cite that references yourself), but your claim of a pronounced downtrend beginning in 2002 is nowhere to be seen in the most current graph now showing through 2010.
http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/
This is in fact the link you cite in your own blog.
So, would you care to explain this obvious discrepancy or retract that particular comment, as it now seems to be in error (or it seems you’ll need to find another source in order to continue to support your statement).
Sorry, I don’t know from Tsch, but I’m still trying to nail down the details of energy, heat and radiation. I hope it won’ be on the exam.
Can you help me out with correcting anything wrong or missing in the following?
A photon entering the space of an atom has a certain probability of being absorbed. If absorbed, the time for which the photon energy is held depends on factors such as energy of the photon and structure of the atom. Most such photons are quickly released because they have an energy that is wrong for the atom. A quickly released photon is most likely to be emitted in a direction close to its original trajectory, but not always. That’s called reflection.
Selective absorption of radiation (be quantum increase of an electron’s angular momentum) such as done by pigment molecules does no work. It exists as potential.
In nonradiative relaxation, the energy is released as phonons, more commonly known as heat.
Kinetic transfer is conduction.
Thank you for making yourself available for questions as well as for the lessons.
Maybe this discussion should be over in How Much Work can One Molecule Do?
The International Journal of Modern Physics B seems to need to raise the bar of its peer review (?).
I’d like to see this last question of the post answered by them.
Alexandre’s comment inspired me to write to them.
I sent this off to the editor:
Arthur Smith has a great paper on arxiv on G&T here: http://arxiv.org/abs/0802.4324
He outlines the main part of his argument here: http://arthur.shumwaysmith.com/life/content/the_arrogance_of_physicists
He focuses on G&T’s (correct) claim that the earth has an effective radiating temp of 255K. One place where G&T go wrong is in explaining how earth can have a higher avg temp than its radiating temp…
I have never used the G&T paper as the basis for my position on AGW theory.
I would point out, however, that until quite recently it was standard AGW believer strategy to talk very plainly about a greenhouse effect and to use greenhouses as examples of this. If it were not so well rooted in AGW lore, I am certain less trouble would be taken to clarify the distinction today.
I appreciate that you are one of the growing number pointing this out.
It is AGW promoters who sold the public on the fallacious view of climate that has been dominating the public square and influencing policy. G&T is not responsible for this. And even if they are ‘wronger’ than scienceofdoom points out, that does not make AGW any ‘righter’.
“I am a skeptic and in fact a former NASA scientist (but not a climate scientist).”
Congratulations!
“I do not appreciate your implication that most NASA scientists and skeptics are deluded and wrong. Both sides on this issue have several good scientists and also many wrong ones,”
I agree. I make no comment about your many/most distinction, because I don’t know the numbers, but when I say “scientists” I mean some scientists, not all scientists. To be more precise, I mean those particular scientists who let duff greenhouse explanations pass if it agrees with their own conclusions, but protest loudly if it does not.
I think it’s fair to say that most, meaning more than 50% of all scientists, have not stood up and publicly corrected the record. But that’s different.
On this blog the focus is on the science and less about what “some people might have done” or “some people should have done” or “shouldn’t” etc.
I added this point to the ever-increasing Etiquette page.
We all have our views on stuff people have done but other blogs are much better places for those discussions.
[…] Miskolczi’s paper. And if you celebrated either of those, you shouldn’t be celebrating Gerlich & Tscheuschner because they will be at odds with the previous ones (as far as I can tell). And if you like Roy […]
hunter said:
“I would point out, however, that until quite recently it was standard AGW believer strategy to talk very plainly about a greenhouse effect and to use greenhouses as examples of this. If it were not so well rooted in AGW lore, I am certain less trouble would be taken to clarify the distinction today….It is AGW promoters who sold the public on the fallacious view of climate that has been dominating the public square and influencing policy. ”
—-
You seem to be confused between climate science (as practiced by scientists of multiple disciplines which have applications to understanding Earth’s climate) and everything else you might glean from the media, beginner science books, or the Discovery Channel. Climate physicists haven’t been confused between the behavior of greenhouses and that of Earth’s climate due to “greenhouse” gases (infrared active gases) in our atmosphere. That matter was settled ~ 1 century ago. No “distinction” is required by those who understand something more than the rudimentary physics.
Since I do not know the origin of the misnomer, “greenhouse effect”, as applied to climate, I will not make unsupported assertions. However, I will venture to guess that during an early breakthrough in our understanding of Earth’s variable climate (perhaps the 1950s), someone who knew better attempted to explain and distill a bit of the complicated physics to a media representative of a largely science-illiterate public. Continuing my guess, the scientist being interviewed decided to create an analogy of an important process of Earth’s climate by comparing it to a phenomenon gardeners have experience with. All analogies fail, although some are far better than others.
As an astronomer, I can tell you that this sort of thing happens with annoying frequency. Perhaps you have heard of the “Big Bang Theory”? Look up how we were stuck with that incredibly unfortunate name, which has been the source of many popular misconceptions ever since.
Which “fallacious views” are you referring to? Be specific, and provide attributed references. And who are these “standard AGW believers” promoting greenhouses to explain why Earth isn’t an ice planet? And what has any of that to do with anything important: e.g., decisions to be made regarding Earth’s (near)future climate and its effect on civilization? Neither the science nor the scientists are changing their tune, as you seem to allude. What is occurring is a massive disinformation campaign.
The paper by G&T was classified as a “review” article, which means it most likely appeared by invitation of an editor and did not necessarily have the normal full peer review process applied.
You can read a description of the journal at “Aims and Scope”: http://www.worldscinet.com/ijmpb/mkt/aims_scope.shtml
You will note that the journal describes a “unique feature” being the review section, which “contains articles with permanent research value besides the state-of-the-art research work in the relevant subject areas”, and “To ensure top quality, review articles are by invitation only and all research papers undergo stringent refereeing.”
It seems that G&T was a “review” article, which would suggest a problem with the protocols by which they invite articles. The topic of G&T is, after all, not the focus of the journal and neither of the authors have any publication record in atmospheric thermodynamics either.
All in all, it seems to have been something of an aberration for the journal. But to their credit, they have also subsequently accepted and will shortly publish a paper which has been through the review process and points out some of the major errors in G&T.
It should appear within a couple of weeks, I think.
I am interested… what made you notice this article now? I am a minor co-author of the rebuttal, and am interested to see the paper starting to be noticed again as the rebuttal approaches a publication date.
Cheers — Chris Ho-Stuart
Spaceman Spiff,
This is brief reply.
According to a quick wiki, the term greenhouse effect was adopted in the very earliest days, so no Exxon conspiracy on that one. (just kidding)
http://en.wikipedia.org/wiki/History_of_climate_change_science
AGW, for me is divided into two basic movements: the social movement, that has marches, NGO’s raising huge funds, movies on inconvenient things, expensive conferences, favorable press coverage and, most importantly, policy demands. This AGW brooks no dissent, breathlessly follows temperature fluctuations in the 0.0xo change range, worries about polar bears and thinks the world is ending even as we speak.
Then there is the science, which shows that climates change and that humans can influence these changes.
There is at this time no clear frontier between the two movements. There are lots of people wearing multiple hats.
As for your concern about a ‘massive disinformation campaign’, are you referring to what was uncovered in climategate and elsewhere, or the self-dealing of the IPCC leadership, or the assertions that climate today is changing in dangerous and unprecedented ways?
Chris Ho-Stuart
Thanks for posting and letting us know about the situation – it will be wonderful to see your paper “in print”.
One of the things I do is try and understand the common problems that people have in understanding climate science. Part of that is from comments here and part of it is from posting comments myself on other blogs and seeing the responses.
G&T is sometimes raised in the theme of: “so clearly there is a problem with the ‘greenhouse’ theory”. Some of those people are just looking for intellectual support for a deeply-held conviction, but some commenters and many more readers want to understand the real story.
And as I stated at the start of the article, a few recent comments made me pull out the paper and read the whole thing properly. Doing so I realized that a large number of comments on other blogs (and a few on this) were directly attributable to G&T.
The G&T article appears – to someone without a science background – to be a thorough dissection of this aspect of climate science. Rather than a badly written paper by people who know almost nothing about climate science.
– Your comments are welcome if I have missed the mark with any criticisms.
And please let us know when the paper is published.
“On this blog the focus is on the science and less about what “some people might have done” or “some people should have done” or “shouldn’t” etc.
I added this point to the ever-increasing Etiquette page.”
Noted. Presumably that also applies to all the comments about how the “intrepid duo” should have read a physics book…?
OK, I’ve got a question about the science.
Consider a hypothetical and rather exotic alien planet, with some strange properties. It has a pure nitrogen atmosphere with no greenhouse gases, but it’s very thick – about 100 bar at the surface. High up in the atmosphere, about 100 km off the surface there are clouds of buoyantly floating alien lifeforms; to shortwave (5000K) and far longwave (300K) they are black on top and silvered on the bottom. To intermediate longwave (1300K), they are transparent. (I don’t know whether there is such a material, but follow along for the sake of the thought-experiment.) The clouds are thick and dense enough to obscure 90% of the incoming solar radiation. There is the usual difference in incoming heat between equator and poles.
So, some observations:
The outgoing longwave from the surface is not trapped – it all radiates directly to space, unimpeded by the transparent nitrogen atmosphere and life-forms.
Convection occurs due to the equator-pole difference in heating.
In the shortwave spectrum, the planet appears to have a nearly black surface 100 km above the true surface.
So the black clouds ought to settle at roughly the radiative equilibrium temperature around 250-300K, and as gas descends to the surface it is adiabatically compressed and increases in temperature. This makes the surface far hotter than the radiative equilibrium – a greenhouse effect.
With a ~10K/km adiabatic lapse rate and clouds 100 km high, the surface could be 1000K hotter than the expected equilibrium.
But the outgoing radiation is not trapped, there are no greenhouse gases, and the upper atmosphere is not providing more down-welling radiation than it would get on a planet without clouds.
So is it true to say that the greenhouse effect is generally due to “trapped” out-going longwave and downwelling radiation?
Or would it be more correct in a convective atmosphere to say that it is due to radiation to space occurring on average from a high altitude combined with a lapse rate between this altitude and the surface? Which mechanism best controls/explains the amount of warming?
(For reference, I am thinking of the explanation in Soden and Held, “Water Vapor Feedback and Global Warming”, Annu. Rev. Energy Environ. 2000. 25:441–75.)
I’m sure my standards might depart from the Etiquette from time to time, in which case, I hope people pull me up on it.
From the etiquette: “If posts or comments are poor, bad science, or missing the point, you don’t have to spare the punches. You can even be insulting in an amusing/satirical kind of way.”
This also applies to other people’s work. I’m sure they’ve read physics books, lots of them. Just no modern climate science.
To meet the etiquette’s high standards we need to stay talking about what people have written and said on the topic of science.
“To meet the etiquette’s high standards we need to stay talking about what people have written and said on the topic of science.”
Of course. Which is why I invited comparable comment on what the NASA web page had written on the topic of science.
It seemed to me that the ultimate source of the misunderstandings in this area was the lack of generally accessible and accurate explanation – why I think G&T could quite easily be unaware of the modern science, and why they could get away with their strawman paper.
Please, don’t get me wrong. I do appreciate and admire the generally polite and scientific standards here. I just thought that since you seemed to be discussing the sources of the misunderstandings, with a humorous but quite noticeable barb to your comments, I’d be able to add my own perceptions of them in the same vein. I apologise if that caused a problem.
Enough said?
No problem at all.
hunter said:
“As for your concern about a ‘massive disinformation campaign’, are you referring to what was uncovered in climategate and elsewhere, or the self-dealing of the IPCC leadership, or the assertions that climate today is changing in dangerous and unprecedented ways?”
I will address the first of these. You must be referring to the **illegally hacked** emails from East Anglia University, right?
——sorry, the rest deleted for being off-topic, even though it is a response to hunter who has veered off-topic—
—– Many people want to discuss —gates and “stuff people have done” and “stuff people have not done”, but not here, and at some arbitrary point I will chop and delete emails.—
Spaceman Spiff,
Clearly our host is to be respected. Perhaps at a slower website you will be able to post the link to the conclusion you refer to? Perhaps Climate Skeptic, which is unmoderated. But I think it is clear which hat you wear in my AGW cosmology.
scienceofdoom,
Sorry about that. I was trying to get Mr. S Spiff to clarify something he had said earlier.
scienceofdoom:
I offer my apologies for moving off topic.
Hi S.o.D.
Two questions.
1. What is your science background.
This is important as it can cut out unnecessarily simplified explanations directed at you.
I guess it is not Physics but I could be wrong.
2. Why are you at such pains to justify the emissivity of the surface of the planet as being 1 whereas most others use a figure of 0.5 to 0.7 ?
Bryan:
They don’t.
Well, not anyone writing about the wavelengths of interest for surface radiation. The emissivity of the earth’s surface in the “longwave” region is typically between 0.96 and 1.00.
See The Dull Case of Emissivity and Average Temperatures.
In this article you can see how emissivity varies with wavelength for many different surfaces.
Careful with emissivity. It is a frequency dependent value.
Emissivity in the shortwave may be that high, because so much shortwave radiation (visible light) is reflected. Emissivity in the longwave is invariably very close to 1.
For calculating the radiation emitted from a planet, you need longwave emissivity, which for Earth tends to be about 0.99. Thermal emissivity for water, land and ice akk are up near 1: see http://www.icess.ucsb.edu/modis/EMIS/html/em.html
The link there is to the the MODIS (Moderate Resolution Imaging Spectrometer) UCSB Emissivity Library; it is the values that you need for longwave emissivity (thermal, or infrared) used in satellite sounders, and also for calculating thermal radiation.
If you give a link for the values 0.5 or 0.7, I am sure you will find it is for shortwave bands which have almost no role in the thermal radiation emitted from the surface.
Cheers — sylas
Hi S.o.D.
You seem to be shy about revealing your scientific background.
I have no problem with that, I have a Physics degree what about you?
On the emissivity question the table below gives;
Snow 0.82
Water 0.67
Sand 0.76
http://www.omega.com/temperature/z/pdf/z088-089.pdf
I am not particularly interested in the value of e for one or two wavelengths but more for a value for the total spectrum of surface radiation.
The one with the value of 390W/m2
Bryan
You should be interested in the value of emissivity for the 4-30um wavelength range.
This is the wavelength range for most of the radiation from the earth’s surface.
An average number across all wavelength is useless in doing the calculation of radiation. You need to consider the Planck function for the temperature under consideration.
Many surfaces have totally different emissivities at different temperatures:
For example, you can see that white paint is not reflective at all once into “longwave”. You can see that snow is highly reflective for “shortwave” but highly absorbing for “longwave”
Why use an average when you have the actual values of interest?
You can see the actual values in the link I gave already.
Given that these painstaking numbers have been measured and provided – why use an incorrect average?
Bryan, the value given for water in that table is flatly incorrect. It looks like a typo with a mix up of a 6 and a 9 somewhere. A value of 0.97 would be reasonable.
The emissivity of water is at least 0.95 and for emissivity from the ocean in IR bands it is more like 0.98 or 0.99. This is what matters for calculating the 390 W/m^2 surface thermal emissions.
You can confirm this from all kinds of sources if you like. Science degrees don’t come into it. Your science degree is a total red herring here; you are not using any expertise on the matter (obviously!). So trying to pull rank with credentials backfires.
Water is the single most important factor for Earth’s emissivity. Not only is the Earth mostly ocean; but the high emissivity of water plays an important role in high emissivity for vegetation covered surfaces.
I am very curious as to how you came to cite this page. I suppose you could have googled it and been unlucky enough to come up with a page having such a typo. Or did you find this page cited somewhere else? I would genuinely like to know; sometimes an error like this gets spread about simply because it is convenient as support of an already established but erroneous conception; so the page is quite likely to get cited simply because it is so badly in error!
The page gets ice and snow about correct, however. Ice is 0.97 to 0.98, and snow is either 0.82 (fine particles) or 0.89 (granular). The higher values, for ice in particular, are most relevant for colder regions of the planet.
The remote sensing library I cited previously notes that
“Water, ice, and snow generally have a high emissivity, 0.94 to 0.99, across the thermal infrared region.”
Since you mention credentials, I should underline that this is definitely NOT a case of something where experts would be at all in dispute. You’ve simply cited a source that gives an incorrect number for some reason, and lack the background to recognize it is wrong. There’s nothing wrong with failing to know this right off; whatever your credentials, you can check the emissivity of water (sea water especially) for yourself by trying to find a range of sources. You will soon discover that the 0.67 value is hopelessly incorrect.
And, by the way, the discussion of the subject of emissivity by Science of Doom is very good. Dispassionate, accurate, well referenced, and giving a good summary of the subtleties of emissivity and wavelength dependence. See: The Dull Case of Emissivity and Average Temperatures, which he cited previously.
SoD and Sylas
Something happened to my last post 4.51 when posted it seemed to vanish for about an hour on my computer at least.
I thought it had been lost and perhaps answers Sylas question of why I cited a particular page.
There is no hidden agenda behind asking SoD about his science background merely wanting to know at which level to frame my comment.
Which is;
The back radiation shown in the KT diagram has a huge magnitude of 324W/m2.
Yet no-one can get this radiation to do any WORK!
Since the ability to do work is a qualification to be described as HEAT then this radiation cannot be heat.
I contend that this radiation is made up largely of very low energy photons that cannot in this situation find a sink.
Its a bit like a person in a bath of water at 30c asking for a top up of hot water from a kettle.
A helpful person pours in a large kettle full of water at 28c which irritates the bather no end.
Although a large amount of energy had been added to the bath no heat had been added.
I am therefore very keen to pin down the energy content of the “back radiation” for its FULL electromagnetic spectrum not some conveniently abbreviated slice.
You can’t really use backradiation to do work, because it has a characteristic temperature of only 2° C. To do work, you would need to have something colder than that as your heat sink. Not very efficient!
This isn’t relevant though. No-one proposes using the backradiation to do work. And the actual HEAT flow is upwards, because the up radiation is even more than the 324 backradiation down.
This is precisely where Gerlich and Tsheuschner’s paper goes so very badly incorrect. They talk about work, and violations of the second law, and so on in a way that is physically nonsensical. There is no violation of the second law; the heat flow is upwards as we expect, since the surface is warmer than the atmosphere.
You are still one heck of a lot warmer than you would be without that backradiation though. You speak of the bath. The issue is not about actually adding heat to the bath, but with how efficiently the heat is being taken away. To get a more reasonable comparison, presume you have a heater for your bath (analogous to the Sun heating our surface) and your bath being a metal tub sitting in a large puddle. (The heat added by the heater is carried away through the puddle.) Now, having a puddle at 5 degrees or having a puddle at 20 degrees will make a huge difference to the temperature your bath can maintain! That the heat is flowing from the bath into the puddle obvious. But… how quickly does the heat go?
The more backradiation, the less effectively the surface can shed heat, and so the higher the surface temperature will be.
Backradiation is directly measured, by the way. The earliest refereces I have for measurements are in 1954. See:
Stern, S.C., and F. Schwartzmann (1954) “An Infrared Detector For Measurement Of The Back Radiation From The Sky”. J. Atmos. Sci., 11, 121–129. This obtained values in Maryland, and they were in the range 314 to 405 (daytime) and from 206 to 312 (nighttime), limited to clear sky conditions.
I also recommend A First Course In Atmospheric Radiation by Grant W. Petty. Chapter 8 (“Atmospheric Emission”) contains a number of more details measurements, showing the spectrum of emissions made in a number of different locations, from ground level and from space.
By the way, I am the “Chris Ho-Stuart” who wrote above as well. I usually use the pen-name “sylas”. Our rebuttal to Gerlich and Tsheuschner should be appearing within a few days, all being well.
I take your point about credentials, but I still think it is not a helpful question. Science of Doom is citing and using the scientific literature, so you don’t need to talk down to him. You can be as advanced as you like.
Can I also put in a quick plug for a new bulletin board I have started. It is Climate Physics Forums. It is intended as a space for people who have an interest in physics and science generally to discuss the science relating to climate. It is intended to encourage courteous and substantive discussions. There is no official policy on the answers, and you would all be very welcome. The bulletin board format is quite good for these kinds of discussion.
Cheers — sylas
Whilst I am happy with the Second law, I’m not sure that its generally used expression (heat flows from the hootest to the coldest unless you do work) is applicable to the upper atmosphere.
Here we have a relatively dense, but cold Tropopause (9km deep according to the standard Atmopsphere) radiating photons at CO2 frequencies (primarily the 15um band) into the thinner but hotter Stratosphere.
Each photon doesn’t know that it came from a cold place. Its just a photon, with energy content defined by its frequency.
Similarly an absorbing CO2 molecule doesn’t know that the photon came from a colder place. It just absorbs it anyway…
Presumably if the emitting surface was very dense but much colder, it could occur that NET energy might be transferred from the colder to the hotter.
Does anyone have any thoughts (or numbers)?
Colin, I can’t give you actual numbers off the top of my head, but in the upper atmosphere the same basic rules apply. There is a net transfer of heat from the upper stratosphere back down towards the troposphere, in the direction from hotter to cooler. However, it is very small.
The reason it is small is because the air is so thin. The actual heat content of the thin stratospheric air is small. The capacity of a gas to absorb tradition is a function of the path length as well as how much is absorbed per unit length. We speak of “optical depth”, which an indication of how far radiation goes before being absorbed. I believe it is usual to quote the distance over which half the radiation is asborbed as optical depth. The stratosphere, being so thin, has a very deep optical depth, even in bands where some radiation is being absorbed.
It is particularly interesting that in the upper atmosphere, the major effect of greenhouse gases is to cool the atmosphere by giving more effective emission, rather than heat the atmosphere by absorption. This is also closely related to the “lapse” rate, or whether temperature is increasing or decreasing with altitude. In the stratosphere, there is no heating effect from below. Any radiation which is capable of being absorbed will have already been absorbed lower down, and is re-radiated with a cooler characteristic temperature.
Hence, from the stratopshere looking down, what can be “seen” in the bands where thermal radiation can be absorbed is basically the tropopause… the coldest part of the atmosphere before temperatures rise again in the stratosphere. The tropopause, being so cold, cannot be giving a net flow of heat to anything else.
The rise in temperature in the stratosphere occurs mainly as visible light and ultraviolet light is absorbed, from the Sun. The ozone layer in particular is good at absorbing ultraviolent (and hence preventing it from reaching the surface, fortunately for us). The greenhouse gases, on the other hand, main contribute to shedding that heat again, both up into space and down into the troposphere. The net energy flow is much too small to have much consequence for the surface; but it does have an important role for establishing the temperature structure of the upper atmosphere.
The numbers, in terms of W/m^2 actually emitted or absorbed, are very small, simply because the air is so thin.
Cheers — sylas
sylas
……This isn’t relevant though. No-one proposes using the backradiation to do work………
Hence backradiation cannot be considered as HEAT.
You are now in full agreement with G&T on that point, well done.
The link I gave you to emissivity values was supplied by a provider of precision measuring equipment.
One would have thought that they had no particular axe to grind one way or another.
However that cannot be said about all other parties in this area.
Al Gore, Lord Oxburgh and Hedge funds under Mr Soros have taken positions on climate change that potentially win or lose billions of dollars.
Because you don’t like a value in the table you describe it as a “typo”.
Throughout the climate change debate there has been a tendency to “round up” the data to prove a particular point.
Small changes always “rounded up”, made in the same direction can lead to seriously wrong conclusions.
Here we find even using your own figures you would like to “round up” to e=1.
It can be shown that using real values for e that the sums in the KT diagram
Just dont add up.
You need to remember the difference between heat and heat radiation. The flow of radiant heat is equal to the heat radiation up minus the heat radiation down.
G&T confuse the whole issue mightily. The plain fact of the matter is: backradiation is thermal radiation, or heat radiation, coming from gases in the atmosphere that interact with the IR bands of the spectrum. If those gases where not there, the surface would be much colder, by about 33 degrees. There is no violation of the second law in any of this; it is basic thermodynamics which has been known for over a hundred years. In modern times we measure it more accurately; but the principle by which greenhouse gases give a much warmer surface temperature are not new and not in doubt.
There are good descriptions of this effect in a public lecture given in Victorian England by John Tyndall, in 1863 or so, who first discovered the capacity of certain gases to be opaque the infrared thermal radiation… the very bands in which stuff at normal temperatures emit thermal radiation by virtue of temperature, also called heat radiation.
I suggest the value of 0.67 might be a typo simply as a guess for why it might have been so wrong. That the value really is about 0.97 is basic information; having nothing to do with presumptions or preferred values, but simply knowing a bit about the subject. It’s somewhat basic thermodynamic general knowledge; and not particularly associated with climate at all.
You might be interested to look at the manual for the OS530LE, OS532E, OS53xE-CF, OS533E, OS534E, OS530HRE, OS523E, OS524E OMEGASCOPE® Handheld Infrared Thermometer (same company) which includes includes a more correct value for water of 0.95 to 0.96 (Ref:
http://www.omega.com/Manuals/manualpdf/M4088.pdf)
Alternatively, as I suggested, you could look at any other source. Other disinterested companies would be fine.
At http://www.infrared-thermography.com/material-1.htm (distilled water given as 0.98)
At http://www.thermoworks.com/emissivity_table.html water given as 0.95
At http://www.roliv.com/emissivity-values-definition-and-coefficients.html water given as 0.95 to 0.963
And so on, and so on, and so on. Companies like omegaworks, reference works, sensing tables, etc etc.
If you want to sort out whether the value of 0.67 is valid, you simply need to check it. My motives are irrelevant. The FACT is that the thermal emissivity of water is nowhere near 0.67, but it IS around 0.97. You discover that by actually checking the information. If you prefer to assume that omegaworks is more trustworthy than me, or any of my references, that’s up to you. I don’t really mind.
I simply am trying in good faith to help explain the relevant physics. For my part, I don’t consider it a fight, or a reason to speculate on motives.
I had already, by the way, emailed omegaworks to let them know of the error, even before I posted previously. I expect they will appreciate the information.
I remain very interested, seriously, to know how you got that reference? Did you google it yourself, or did you find a link from some other climate discussion site?
Cheers — sylas
Sylas
…….heat radiation up minus the heat radiation down…..
There is no heat up and heat down.
There is only heat transfer from higher temperature body to lower temperature body.
To state otherwise implies a violation of the second law of thermodynamics.
The page you refer to was simply googled for emissivity.
You may be surprised that a sceptic like myself will not accept your emissivity figures without checking other sources.
However as with the Hockey Stick and the temperature record of the CRU we are well justified in checking for ourselves.
Use the SB equation to check what figure for emissivity corresponds to the surface radiation of 390W/m2 given in the KT diagram above.
Bryan
Perhaps this is the same Bryan from http://climateresearchnews.com/2009/03/new-peer-reviewed-study-falsification-of-the-atmospheric-co2-greenhouse-effects-within-the-frame-of-physics-by-gerlich-tscheuschner/ with whom I discussed the subject already?
And who said:
And then I asked what happened to this radiation when it “reached” the earth’s surface.
Perhaps you are not the same person?
Interested readers can review this fascinating debate at that link – which is following a strangely similar pattern here.
Q. Radiation takes place from this cold atmosphere?
A. Maybe, yes..
Q. Radiation reaches the surface of the earth?
A. Yes of course.. (in this particular perspective)
Q. Radiation has zero effect on the surface of the earth because it vanishes – bends around the earth – please suggest the solution?
A … … … Change of subject.. finally “You are talking nonsense”
In the meantime random claims about the downward radiation being due to Rayleigh scattering, abandoned without clarification..
And sadly, confused people like myself who just want to learn and who don’t currently understand the amazing subject of thermodynamics can’t find out what the real story is.
What happens to the mystery radiation?
No one can answer..
In another interesting post: The Imaginary Second Law of Thermodynamics many attempts were made to explain to me the exact and correct use of the terms heat and energy, and exactly the correct use and misuse of vectors in connection with radiation..
But still, I have yet to find out what happens to this mystery radiation from the colder atmosphere. Or if it even exists. After much patient explanation by one visitor about the correct use of terminology I am still in the dark about the really important subject.
I feel that my use of terms heat and energy can be improved and definitions tightened up. And vectors, of course, much improvement needed there also.
Perhaps we should rename the Gerlich & Tscheuschner paper “On the Slight Tightening up of Thermodynamic Terms within the Frame of Climate Science”
At least, until such time as the comedic duo, or one of their apostles, can explain whether this radiation from the atmosphere
a) exists
b) reaches the earth’s surface
c) and what effect it has when it reaches the earth’s surface
However, I expect once again to find what a fool I am for not understanding thermodynamics as the apostles of this movement are unable to lower themselves to fully explaining the mysteries.
And just to hear “heat can only flow from a hotter to a colder body” which I already know and agree with.
If only I could grasp this subject! If only someone could explain it!
By the way, if you are not the same Bryan, you can just ignore the comments – I put them here along with the link so that new visitors can follow a well-worn discussion
Maybe rather then ridiculing G&T, you should read their paper again, because they mention what you are supposedly missing:
“Exactly this was done wellmany years ago by an expert in this field, namely Alfred Schack, who wrote a classical text-book on this subject [95]. 1972 he showed that the radiative component of heat transfer of CO2, though relevant at the temperatures in combustion chambers, can be neglected at at-mospheric temperatures.”
and
“Clausius examines thoroughly, that the second law is relevant for radiation as well, even if image formations with mirrors and lenses are taken into account”.
Schack’s work is for heat transfer within the atmosphere, not for the surface and the atmosphere to space. Your citation is therefore irrelevant. The greenhouse effect does not, in fact, violate the Second Law so your Clausius quote is also irrelevant.
Oh, and Schack was likely referring to path lengths in meters, not kilometers. It makes a difference. The effective path length at one atmosphere constant pressure from the surface to space is about 8 km.
The variable of interest for calculating radiative heat transfer using lookup tables or charts as in Schack is the partial pressure of the absorbing gas multiplied by the path length. So for CO2 at 400ppmv or about 0.0004 atmospheres with a path length of about 8,000m the value is 3.2 atm m. That’s quite a lot of CO2 and significantly affects heat transfer.
I had a similar discussion with someone who shall remain nameless several years ago. As the line goes, I can explain it to you, but I can’t understand it for you. If you can’t admit that you could be wrong, you’re posting in the wrong forum.
Vaas: Alfred Schack appears to have believed that CO2 had negligible effect on the GHE because of the overlapping absorption with water vapor.
https://onlinelibrary.wiley.com/doi/epdf/10.1002/phbl.19720280106
The last two sentences of the abstract translate to: “Prof. Schack points out that the CO2 content of the atmosphere is practically without influence. The main reason is the water vapor content of the air.”
And Schack is correct near the surface where CO2 was/is 300-400 ppm and water vapor is 10,000+ ppm. However, the amount of water vapor in the atmosphere drops with altitude – to 3 ppm by the tropopause.
If you go to the online Modtran radiation transfer software and look down from
0.5 km, the calculated upward flux is the upward flux is 442.7 and 442.4 W/m2 with 300 and 600 ppm CO2.
If you look down from 2 km, the calculated upward flux is the upward flux is 411.0 and 410.4 W/m2 with 300 and 600 ppm CO2.
If you look down from 5 km, the upward flux is 365.2 and 363.9 W/m2 with 300 and 600 ppm CO2.
And if you look down from 70 km (the “TOA”), the fluxes are 299.9 and 296.6 W/m2.
http://climatemodels.uchicago.edu/modtran/
This provide a viable explanation for how Schack arrived at we now know is the wrong answer.
And the operatic duo, in their tragedy, actually produce the equations of radiative transfer.
Apply these equations, with the absorption lines known from experimental spectroscopy on CO2, water vapor etc, and you find that more CO2 reduces the outgoing longwave radiation from the earth.
Which means the earth warms up, due to the first law of thermodynamics.
But our operatic pair don’t mention the results, they just show the equation as if to say, look, no one is using this!
This implication works on those “educated” by fantasy climate blogs, but for anyone who has studied the subject.. um, yes, this is what everyone uses, and.. did you have a point G&T?
That’s why it’s clear, they were having a laugh.
Vaas: Most of G&T’s paper is about oversimplified nonsense that is used to convince the public that the GHE and enhanced GHE are simple phenomena that have been understood for more than a century: greenhouses, Arrhenius, Planck’s Law and the SB equation (which apply to radiation at equilibrium with its surroundings an equilibrium which doesn’t exist at some wavelengths and altitudes. Since professional climate scientists use radiative transfer calculations, G&T are rejecting what turn out to be strawman arguments.
However, on pages 49 and 50, G&T questions the assumption that the atmosphere is in local thermodynamic equilibrium. In other words, that the fraction of excited CO2 molecules in the atmosphere depends only on the local temperature and not on the local radiation field:
“This assumption of Local Thermodynamical Equilibrium (LTE) is ruled out by many scientists even for the extremely hot atmospheres of stars. The reader is referred to Chandrasekhar’s classical book on radiative transfer [93]. LTE does only bear a certain significance for the radiation transport calculations, if the absorption coefficients were not dependent on the temperature, which is not the case at low temperatures. Nevertheless, in modern climate model computations, this approach is used unscrupulously”
Climate scientists adjust the absorption coefficients of GHG’s for changes in temperature (Doppler line broadening) and pressure broadening. So that isn’t a problem
Hermann Harde, a very prominent climate skeptic derived the equations of radiation transfer in our atmosphere starting with Einstein coefficients and covering ALL of the details including whether an assumption of LTE is appropriate in our atmosphere. He concludes that LTE valid up to 60 km (if I understand correctly), but above absorption begins to compete with collisional excitation. If I understand correctly, for the strongest CO2 line near the surface about 3.5% of emissions come from stimulated rather than spontaneous emission. So LTE is a good, but not perfect assumption here. So he ends up with three derivations of the Schwarzschild equation for radiative transfer. Both he and the consensus use this equation when scattering is negligible to calculate radiative forcing. Harde comes out with a different result because he and the consensus calculate radiative transfer through different atmospheres. So, after carefully considering the issues G&T raised, an equally skeptical physicist endorses the use of equations 60 and 61 for radiative transfer calculation in our atmosphere
https://www.hindawi.com/journals/ijas/2013/503727/
G&T’s complain about Figure 23, which is derived by the “two stream approximation” for radiation traveling in three directions. Equal emission of photons in all directions is decomposed into three fluxes: the component of energy flux in the +z direction for photons emitted upward (even slightly}, the component of energy flux in the -z direction for photons emitted downward, and the components of both emitted in the horizontal x and y directions, which approximately cancel. This is how climate science simplifies the problem of 3D radiation transfer to a one-dimensional fluxes in the +z and -z directions. (Sect 3.7.2).
SOD wrote: “And the operatic duo, in their tragedy, actually produce the equations of radiative transfer.”
G&T produce the equations of radiative transfer ASSUMING local thermodynamic equilibrium exists and question whether that assumption is valid in our atmosphere. It is a reasonable question, but it was G&T’s job as scientists to come up with some evidence that the assumption of LTE is wrong. Nevertheless, the path from the most general equation of radiation transfer (which is inherently three-dimensional) to the one dimensional fluxes in energy balance diagrams is rather obscure. None of my text (Petty, Pierrehumbert and Hobbs and Wallace) cite any primary sources demonstrating that LTE is a valid assumption, and Pierrehumbert doesn’t even index the term “local thermodynamic equilibrium”.
The best answer may be the one you provided in this post: Radiative transfer calculations are consistent with what we observe happening in our atmosphere under a wide variety of conditions.
https://scienceofdoom.com/2010/11/01/theory-and-experiment-atmospheric-radiation/
Bryan, you say: “There is no heat up and heat down.”
That is true, and it is PRECISELY why I was so careful to define terms accurately. The term “heat”, by itself, represents the transfer of energy between bodies by virtue of temperature. OK?
As well as this, the word heat combines with other words to make phrases. There is “heat radiation”, “specific heat”, “latent heat”, “heat capacity”, and so on. As I explained in my previous post:
Read that again carefully. The “heat” transfer is equal to a difference between the energy flowing as “heat radiation” up and “heat radiation” down.
Clear?
A simple worked example will help. Take a blackbody surface at 2C facing a blackbody surface at 18C. There will be a flow of heat, and we can calculate it. Assume only radiant heat flow occurs (it is empty space).
You first put the temperatures in Kelvin. (275K vs 291K). You then use Stephan Boltzman to calculate the flux of heat radiation in each direction, using σ.T^4. This gives you 325 W/m^2 one way and 391 W/m^2 the other. The heat flow is thus 66 W/m^2 from the hotter body to the cooler done.
The heat radiation in each direction is real. It can be measured. We DO measure on Earth the heat radiation flux up from the surface and down from the atmosphere, with values quite similar to the simple blackbody example. The flow of radiant heat is simply the difference between the heat radiation in each direction.
So the heat flow is a single value and a single direction. The heat radiation flows in each direction. This is pretty stock standard and precise terminology, and I took particular care in my post to emphasize that you must not mix up “heat” (the net transfer) with “heat radiation” (the radiation emitted from a body by virtue of its temperature and which flows in both directions but with different magnitudes).
There is no violation of the second law in any of this.
You say:
Actually, that is precisely what you SHOULD be doing. I encourage it. I have explicitly suggest you do this above.
I gave a value, you disputed it with an alternative source; the question is; what now? Are you going to go with one of those on some basis of intuition or presumed motives? Or will you check further to resolve the matter?
I have given a number of more sources — including another from the same company you found — to show how this works. What I strongly encourage you do to is NOT to take what I tell you as gospel. I WANT you to check more sources, that YOU find for yourself. Please!
How on Earth else are you going to resolve the difference in values. I can tell you that the value 0.67 is obviously incorrect, and sticks out like a sore thumb to someone who has been working with such things. But that’s just me; you should not base your decision on just trusting me. You should now go and read more than one page picked up with google. Google will give a number of pages. Look at, say, five independent values from different sources. This will solve the problem for you, and will also be far better than merely trusting me!
Oops — Bryan, I forgot to say in my comment above — thanks for confirming how you obtained that page. I really was genuinely interested, and I do appreciate your plain answer.
I was just worried it might have been being used by some other blog or website that was explaining things and confusing matters. Finding it for yourself is much better…. although it does illustrate how important it is to check information you find from a quick google search.
But as before, I truly do not just expect you to take my word for it. I do encourage you to go ahead and look to see what values are proposed for the emissivity of water from different sources.
I’m essentially a campaigner here for physics understanding; not for a particular set of required conclusions on climate. I can’t prove that to you, of course; but for what it is worth, what I love is simply the insights and learning of the natural world available by science.
My primary motive is to help address confusions and errors which is put out in papers like Gerlich and Tscheuschner — which is in all honesty the single worst physics paper I have ever seen get published in a real journal. Not because it conflicts with what I want to be true, or because it upsets some agenda I have; but because it IS to drastically, and hence obscures rather than illuminates as people learn by the physical world works. It is an attempt to deny not “global warming”, but the elementary physics of how the atmosphere works at all to maintain a livable temperature at Earth’s surface.
ScienceofDoom
Yes I am the same person that you had a dialog with in Climate Research News.
I did not realise that you were genuinely seeking information about thermodynamics of which you now say you know very little.
You say “I feel that my use of terms heat and energy can be improved and definitions tightened up.”
…… and I agree with you that a free and easy use of technical language leads to needless misunderstanding.
Sylas for instance could have said long wave radiation rather than “heat radiation”.
At times with Sylas I feel the difference is more apparent than real.
However is seems a little odd that someone who has such little knowledge of thermodynamics should set up a site the main object of which seems to attack Gerlich & Tscheuschner.
Other readers who are interested should look through the file as a number of respondents have reached quite different conclusions about Gerlich & Tscheuschner than ScienceofDoom.
One odd fact should make you think hard about your present position.
In all the sites I have viewed where people state views on this topic I have NEVER come across any person who is professionally involved with Heat Transfer who disagree with Gerlich & Tscheuschner.
Fred Staples and Terry Oldberg and DontBlameCO2 (On the CRN site) identify themselves as such and as being broadly in agreement with G&T
Bryan, I suspect Science of Doom was being sarcastic; but he may speak for himself.
The term “longwave radiation” is not as correct as “heat radiation”. Longwave refers to a particular frequency band, not to how the radiation is produced. What we get from the Sun, for example, is nearly all heat radiation, emitted from the surface at a temperature of about 5700 K, yet we usually call it shortwave in terrestrial energy balance work.
One term I often use is “thermal radiation”, and sometimes also “Planck radiation”. It is essentially the radiation given from a body by virtue of temperature.
The classic reference for this kind of radiation is “Wärmestrahlung” (The Theory of Heat Radiation) by Max Planck (1914). English translations widely available; here is a link to an Online English translation: The Theory of Heat Radiation, by Max Planck.
There is nothing wrong with calling it “heat radiation”; this is a well established usage, and it is good to be aware of it.
I appreciate that terminology gets tricky; but I was careful to emphasize the way I was using terms.
I consider the terminology usage in G&T to be dreadful. More importantly, the issues are far more fundamental than simply terminology. G&T claim that there is a violation of the second law involved in conventional accounts of the greenhouse effect. Their paper is one of the most intemperate I have seen, speaking of other well respected thermodynamic authorities as frauds, or their work as “obscenity”. This cannot be reduced to a simple matter of picking terms! Their physics is incorrect — and they in turn claim that the physics of others is incorrect.
I take with a grain of salt the claims about people “professionally involved with heat transfer” who agree with G&T. What I have seen of the guys you mention doesn’t seem consistent with much of a knowledge of thermal transfer at all. But why are we even bothering with such an indirect level of discussion? Let’s stick to the actual physics on its own merits, for ourselves.
You were asking before about the “level” at which discussion should be engaged. You may assume that I know enough physics to follow what is written in conventional physics journals or text books. I don’t think you are likely to go over my head. The main thing is to be substantive and engage by looking at the actual scientific merits of a case.
Have you tried to resolve the matter of thermal emissivity of water yet? Do try the google search again, and then look at five different references. Normally you get ALL of them in the range 0.94 to 0.99 (it can depend on conditions); if there is an incorrect value showing up it should soon stand out as being an outlier.
Now that you can see how I am using the terms “heat” and “heat radiation”, can you agree that there really is measured heat radiation coming from the sky at around 320 or so W/m^2? Did you see the citation I gave for some of the first direct measurements, back in 1954 before global warming was any kind of an issue? You can also find atmospheric backradiation described back in 1915 and magnitudes estimated before they could be properly measured. (Early energy balance work by Dines)
More importantly, can you agree that there’s no violation of the second law in having 390 or so heat radiation up with 320 or so down, giving a net heat flow of 70 or so upwards? Can you agree that if radiation was not being absorbed and emitted in the atmosphere, then we’d have a much colder surface?
Cheers — sylas
Well, of course, any book by Planck on the topic must be a classic, but only 7 illustrations? Surely the pedagogy of physics has advanced to the point where we can do better than this!
sylas
You say
….What we get from the Sun, for example, is nearly all heat radiation……
Yes since the highest temperature object in our locality is the Sun.
You say
..The term “longwave radiation” is not as correct as “heat radiation”…….
I disagree if the “heat radiation” is said to be going from an object with a lower temperature object to a higher temperature object.
You say
What I have seen of the guys you mention doesn’t seem consistent with much of a knowledge of thermal transfer at all.
Fred Staples was responsible for Heat Transfer calculations for a Nuclear Power Plant.
So unless he was employed at Chernobyl or Three Mile Island I guess he has Heat Transfer pretty well sussed.
You say
…Have you tried to resolve the matter of thermal emissivity of water yet?…..
The main point being that other sources give values for emissivity well short of 1
You seem to be happy enough with snow at 0.82 and sand at 0.76.
However you have not yet calculated the value for emissivity for 390W/m2 for 15 degrees C for Earth surface radiation.
I think that you will find it is e=1 .
The value for a perfect black body.
As usual the IPCC “round up” department at work!
You say
…More importantly, can you agree that there’s no violation of the second law in having 390 or so heat radiation up with 320 or so down…..
The balance of 70 could be described as heat or heat radiation.
The effect of the 320 down would not change the temperature of the surface to any measurable extent.
Two ways to think about it might help.
1. Think about the mass of the Earth compared to the mass of CO2 in the atmosphere.
2. Think of the effect of adding a tiny amount of photons centred around as you say a “characteristic temperature of only 2° C” to a massive amount of photons centred around 15° C
What difference would that make to the average emission temperature of the surface?
Could any such difference plus or minus be measurable with even the most delicate thermometer?
For any readers, who not apostles of G&T and how somehow held their interest this far, hopefully the main points are clear:
1. The downward longwave radiation reaching the earth’s surface is not quite in dispute by apostles of the G&T movement (but see the last point: 4)
2. The fact that the main question (here and in Climate Research News ) of “what happens to this radiation?” is never answered should be very revealing. [See technical note at end for the obvious answer]
Additionally:
3. Bryan never explained what was either wrong with the Incropera text (shown above) and referenced by me at Climate Research News, or what was different between the Incropera text and atmospheric physics.
Instead he said:
(beats explaining what is wrong with it)
4. Bryan, at one stage when being pressed about what happened to the downward longwave radiation “reaching” the earth’s surface, claimed that it was actually reflected radiation:
But when pressed as to why so much radiation arrived in the 15um band – see CO2 – Visualization – just ignored the question and moved back to saying I shouldn’t talk such “nonsense”.
Hopefully Bryan’s comments and lack of answering the important questions will have helped new readers see what an impressive job Gerlich and Tscheuschner have done. I take my hat off to them.
Technical note – Thermodynamics texts, even the most basic ones, treat radiation incident on a surface as either reflected, absorbed or transmitted. On a surface like the earth the transmitted component of “longwave” radiation is zero (where would it be transmitted to?). Therefore, the irradiation is either reflected or absorbed.
The radiation absorbed is calculated by knowing the absorptivity of the material, which is wavelength dependent and can also be directionally dependent. However, the absorptivity at each wavelength and direction is dependent on the property of the material – not on where the radiation came from.
Again this is very basic thermodynamics – not “nonsense”. (If anyone is interested I can post a few more pages on this topic from the same standard work)
This is why Bryan and the other apostles never answer this question of what happens to the incident radiation.
And why, when pressed too hard on this point, will start to claim that it (downward longwave radiation) is not radiated by the various trace gases.
Sylas responded to my pondering if the Second Law holds when you have a massive and large cold body and a thin and insubstantial hotter body. I thank him for his answer, and thinking about it in terms of stars in a sea of 3DegC background radiation, I guess it still holds true.
I agree with Sylas that the Tropopause cannot deliver net energy to the Stratosphere, and in the case of the atmosphere outside the tropics there can be little delivery of CO2 emissions from the Troposphere to the Stratosphere, as these will be all absorbed by the optically thick Tropopause.
There will be some delivery of Water Vapour emissions from the Troposphere (cloud tops?) into the Stratosphere, given the suprisingly large amount of water vapour resident there. Apart from this energy, the Stratosphere must be warmed from above, by absorption of sunlight.
I think you may be confusing what sylas has said… or alternatively im confused by your statements… energy in must equal energy out, or we’d see a gradual increase o earths T vrs time. The amount o energy in the outer atmosphere will effect the rate o change of the lower, but energy will be going both ways, from the troposphere up, and from the stratosphere down…But more will be moving from the warmer body to the colder body than the colder to the hotter.
Yes the stratosphere is mainly warmed by UV through absorption by O3 , but the net flow of energy MUST be from the warmer to the cooler body. (the ole T^4)
I’m not sure quite what we are disagreeing with here, if anything. Colin’s comments seem fine to me, unless I’m missing something.
At any level, the average energy up equals the average energy down. A lot of that energy is simply passing through unopposed, particularly in the rarefied stratosphere. Any energy imbalance anywhere will result in energy being stored, or lost, with a consequent change in temperature, until you get back to the balance of energy in and energy out.
At the stratosphere, most of the energy flow is passing straight through. There’s some shortwave being absorbed (from above) and so (by balance) there’s an matching excess of longwave emitted.
I’ll comment some more on the technical stuff, but just for the record, I have now had a reply from the OmegaWorks group, in response to my email about the 0.67 error. The response was short and to the point.
I might add… anyone can make a mistake. It’s not unusual, and even experts make errors from time to time.
In my opinion, the real sign of genuine technical competence is not how often you make errors, so much as how quickly you can recognize and fix them.
Cheers — sylas
On the emissivity question the table below now gives
Snow 0.82
Water 0.95
Sand 0.76
The IPCC uses the the value for a perfect black body e=1
sylas says
“In my opinion, the real sign of genuine technical competence is not how often you make errors, so much as how quickly you can recognize and fix them.”
So then sylas will you e-mail the IPCC to get them to use a more realistic value?
Given their reluctance to change some other massive howlers like Himalayan glaciers disappearing in 30 years I think you will be wasting your time.
Bryan, Science of Doom has already answered this, but this is basically the next technical point I was planning to address.
It is not the IPCC that uses e=1, but a paper from 1997 on energy budgets. It was known then as an approximation, and identified as such.
The paper has been updated, with new and improved estimates. What is interesting is that they originally used TWO approximations. One was e=1. The other was uniform temperatures. The interesting thing is that these two approximations have opposite effects. Using e=1 gives a larger radiant flux. But using a uniform temperature gives a lower radiant flux (this is a consequence of Holder’s inequality).
Now to be brutally honest, I simply have no idea which way the approximation could be considered as giving more or less emphasis to some agenda. I don’t see myself as having any particular agenda here beyond science education and explanation.
Bryan has suggested that it is rounding in spurious support of some hypothesis… but what hypothesis? I have no idea.
In any case, the funny thing is that the uniform temperature approximation is much more significant, and when more accurate methods are applied you get a LARGER flux from the surface. The revised paper gives 396 rather than 390; and it includes a substantial discussion of how the approximation is made, along with references to other sources and their estimates.
So in summary, I am not emailing the IPCC because:
[*]It isn’t the IPCC making approximations.
[*]The original work clearly recognized it was using approximations, and said so.
[*]There were other approximations used that have the opposite effect.
[*]They HAVE all been corrected in any case.
[*]The biggest source of uncertainty in numbers remains the crying need for more data and better global monitoring systems.
This is not an error; it was never an error. It was scientists using reasonable approximations and saying so up front. The changes in the values with better accuracy don’t actually have a big impact on anything. The main issue here being emphasized by the scientists (Keven Trenberth in particular) is a crying need for more data in order to get a more accurate picture of Earth’s whole energy budget.
References:
[1] Trenberth, K.E., Fasullo, J.T., and Kiehl, J. (2009) Earth’s Global Energy Budget, in Bulletin of the Amer. Meteor. Soc., Vol 90, pp 311-323. (open access link)
[2] Kiehl, J. T., and K. E. Trenberth (1997) Earth’s annual global mean energy budget. Bulletin of the Amer. Meteor. Soc., Vol 78, pp 197-208.
[3] Trenberth, K.E. (2009) An imperative for climate change planning: tracking Earth’s global energy, in Current Opinion in Environmental Sustainability 1:19-27
[4] Trenberth, K.E., and J.T. Fasullo (2010) Tracking Earth’s Energy, in Science 328, 16 April 2010, pp 316-317
The section of the 1997 reference [2] describing the numbers states (p 206)
Page 315 of the 2009 reference [1] describes how the radiance from the surface is obtained, in some detail, including emissivity and temperature uniformity. The value used is improved, but should still be considered an estimate.
The other two papers are emphasizing the need for better systems to get a better picture of energy budgets for the Earth. This data is not needed to prove the greenhouse effect or others such simple basic thermodynamics. It is rather a case of being able to check models more precisely in all the fine details of how energy flows under different conditions, and being able to understand better the finer details of climate conditions to better resolution in time and location.
And as a final point…
I have no idea what the red herring about Himalayan glaciers is meant to indicate. The error there was found by scientists involved in the IPCC itself and was corrected immediately. It was a silly error, but one easy to overlook. It was not in the main science WG1 report (where the matter was correctly described) and it was not reported or emphasized or used in the main summaries. It was an error buried in an enormous report.
Errors like this occur. And they get fixed when found. And you try to make sure they don’t happen again, with better oversight. You would be hard pressed to find any report as large as the 4th assessment report which had fewer errors. That doesn’t excuse the need for avoiding and fixing them, but the idea of reluctance to fix errors is pure poppycock.
On Bryan, for those interested..
The subject is quite well covered in Trenberth and Kiehl’s 2008 update to their “Earth’s global energy budget” paper.
And they are referring to the primary literature on the wavelength dependence of the various substances.
For example, for the wavelengths in question, the emissivity of snow is around 0.99.
As everyone can see in the graphs presented above.
It’s clear from the graph from Incropera and Dewitt (above) that snow is very reflective at “shortwave” (less than 4um wavelength) so the absorptivity is very low at these wavelengths – this is why the earth’s albedo is high for snow and ice – it is reflective at short wavelengths (solar radiation).
And therefore you would expect snow to have an average emissivity/absorptivity across all wavelengths a lot less than the values of interest for 4um – 30um.
Probably most people reading this article and the comments can see that an “average” across all wavelengths is less useful than the measured value at the wavelengths we are interested in.
In Trenberth and Kiehl 2008 they give the effect of those values, like sand, which are down as low as 0.8 for some wavelengths. And they discuss the implications of these lower values for the calculation of radiation from the surface.
And a further problem for Trenberth and Kiehl which I am very surprised that Bryan hasn’t pointed out..
At night it is common to find that the surface is colder than the lower layers of the atmosphere.
Clearly at night time in many places, the surface must stop radiating. Or at least perhaps it radiates and the atmosphere refuses to absorb.
And the converse is true as well, the atmosphere can now radiate to the surface, and the surface will actually start absorbing.
It’s what will be called in thermodynamics textbooks (once they catch up), “a switcharound” as the various parts of the atmosphere and surface suddenly realize what is happening and realign their radiation, absorptivity and emissivity to avoid violating the imaginary second law of thermodynamics.
These Gerlich and Tscheuschner truths show that Trenberth and Kiehl have yet more corrections to make.
scienceofdoom
You say
…At night it is common to find that the surface is colder than the lower layers of the atmosphere……
Yes and because the surface is still radiating it can often freeze if it is humid.
This ground frost is often called radiation frost.
Now this is where the “backradiation” lets us down.
It has a chance to prove it can heat the surface but it fails to do so. – well spotted.
By the way, “don’t blame co2” back at CRN has written an informative post (number 45) which you will find interesting.
Especilly as he is professionally employed in Heat Transfer.
As for yourself your site is full of information well set out which I will make use of from time to time.
What motivates a non scientist to get so heavily involved in climate science?
You have been endorsed by Climate Audit which is quite an acheivment.
During the day, the surface sees radiation from the sun and the atmosphere. On a clear night with relatively low humidity, not humid, the surface will be radiating well in excess of the radiation it receives from the atmosphere alone, on the order of 100 W/m2 in excess. That means the surface cools rapidly. If there is no wind, then transfer of heat by conduction from the atmosphere is too low to maintain the surface temperature and a temperature inversion forms with a fairly rapid increase in temperature over the length of a few meters. The surface, especially vegetation like grass that can’t receive much heat by conduction from the ground, will reach the dew point or wet bulb temperature and water will condense, forming dew, or freeze, forming frost, depending on the wet bulb temperature.
You generally don’t get dew or frost on a cloudy night because radiation from a cloud covered sky is ~100 W/m2 higher than for a clear sky in the mid to high latitudes.
For a hand held IR thermometer, the emissivity of a shiny stainless steel pot is indeed much less than for a black anodized aluminum pot. But if you point it at the liquid in the pot, you get the correct temperature. You also get the correct temperature if you point it at the night sky, presuming the temperature is above the lower limit of the device.
Sylas
You say
…Bryan has suggested that it is rounding in spurious support of some hypothesis… but what hypothesis? I have no idea….
It should be obvious that the Earth is not a perfect black body.
To use the value e=1 (perfect) and then give results to three significant figures demonstrates a tendency to “round up”
The bigger the surface radiation the bigger the back radiation and consequently the bigger the problem.
All the more reason to totally dislocate the economies if the world.
It would be better if they followed the time tested scientific method of experiments.
Then the result would be the result with no need to fiddle the calculation.
Just above, in this comment, I have already answered most of this. The 1997 paper which used the e=1 approximation also used a uniform temperature approximation, which had the opposite effect. The numbers were properly identified at the time as approximate.
More accurate calculations were done in the 2009 paper, where varying values for e and for temperature around the globe were used. The variation in temperature with latitude has the strongest impact, and resolving this means that the original value of 390 was an underestimate, not an overestimate, by roughly 6 W/m^2.
You say:
Apart from the fact that in actual fact the approximations used gave values that were smaller than reality, not larger, this response misses the point. The “problem” is not with backradiation; backradiation is essential to keep temperatures up to a liveable level. The whole global warming issue is actually with CHANGES to the energy balance… and that is simply not addressed in the figures you are quoting.
The greenhouse effect is not a “problem”. It is a part of what makes Earth a good place for life to thrive. Where a problem shows up is when the climate starts to be modified; and whether you round the surface radiation up or down makes no difference to the question of which way it is changing… which is where all the climate change matters arise.
They DID follow the time tested method of experiments and measurements. Did you even read the papers? And I note that you have STILL not responded to the fact that backradiation is directly measured in experiments.
With respect, so far are the one who has been ignoring the readily available empirical experiments and measurements. The papers working out Earth’s energy budget are using loads of direct experimental measurements, and calling for more to continue improving the picture with additional detail.
Cheers — sylas
I don’t know if it made it into the final publication, but the part of G&T near the end where they started talking about how the magnetohydrodynamic (MHD) equations did not contain a term for CO2 was priceless.
The published rebuttal to G&T has now appeared, behind a paywall unfortunately, along with a reply. I am linking to the abstracts, which are available at the IJMP(B) site.
Comment On “Falsification Of The Atmospheric Co2 Greenhouse Effects Within The Frame Of Physics, by Joshua B. Halpern, Christopher M. Colose, Chris Ho-Stuart, Joel D. Shore, Arthur P. Smith And Jörg Zimmermann, in IJMP(B), Vol 24, Iss 10, Apr 20, 2010, pp 1309-1332, doi:10.1142/S021797921005555X
Reply To “Comment On ‘Falsification Of The Atmospheric Co2 Greenhouse Effects Within The Frame Of Physics’ By Joshua B. Halpern, Christopher M. Colose, Chris Ho-Stuart, Joel D. Shore, Arthur P. Smith, Jörg Zimmermann”, by Gerhard Gerlich And Ralf D. Tscheuschner, in IJMP(B), Vol 24, Iss 10, Apr 20, 2010, pp 1333-1359, doi:10.1142/S0217979210055573
My own name is Chris Ho-Stuart; I am a co-author of the rebuttal. I have also provided a thread for this at Climate Physics Forums; see Published comment, and reply, on Gerlich and Tscheuschner 2009.
sylas
Your “comment” and the “reply” are both welcome developments.
Further your new forum and this site with an insistence on rational debate and outlawing personal abuse, promises to advance all our ideas on this very important topic.
Thank you! I appreciate that generous thought! I’ll be trying hard to make the forum a safe place for all persons to engage free of abuse; and a dangerous place for all ideas to stand or fall in the light of their own intrinsic merits alone! I hope it will be fun and challenging for everyone involved.
I’ve been very impressed with what science of doom is doing here as well. His objectives for this blog set a high standard, and some ideals that can hopefully be shared right across otherwise wide disagreements on various topics.
On “errors” and “uncertainties” when giving a final value in a scientific paper
I note what you say about the surface radiation of having an updated value of 396W/m2.
All the figures for e that sylas and SoD have supplied are accurate two significant figures.
However the figures in the above diagram based on two significant figures (for e) are mostly accorded three figure accuracy.
It is this kind of sloppy work that makes sceptics suspicious.
Read the paper. They are explicit about the sources of uncertainty and cite a range of relevant measures and estimates. The value 396 is described accurate within about 2.1 W/m^2.
The whole point of this work is to advocate improved measuring systems that will allow the energy budget to be pinned down more precisely. The major emissivity value, for the ocean, is given to four significant figures, 0.9907, cited to Wilbur 1999.
sylas
When we look at SoDs wavelength dependent and temperature dependent charts there is no way anyone could use them to any more than two figures.
Concrete, fresh water,sea water, sand, tarmac, vegetation of different kinds,snow,dirty snow.
Ocean temperatures and density variations all must have an effect.
It is physically absurd to give an emissivity value to any more than two significant figures .
You don’t have to defend every dot and coma of the IPCC reports.
You would be doing them a favour and increasing their credibility if you could get them to change and issue more physically realistic reports.
It is probably a moot point, but this G&T article is referred to here as dated from 2009. I have a .pdf file I saved dating it to July 24, 2007, and that is the 2nd version (1st version July 1, 2007).
At least one comment by scienceofdoom points out an article by Terbernth et al (2008), which was published after the 2007 2nd version of G&T, and argues that G&T should have known about it. YES, scienceofdoom argues that most of G&T’s science date from 1200 years ago, so one recent article doesn’t refute his main point. I just wanted to point out that the main article dates from earlier than 2009.
I am HAPPY that scienceofdoom and others are addressing this paper. When I read it, the principles in it were over my head, so I did what I do when that happens: I file it away for future reference, hoping that something will come along and clarify it all for me, perhaps pointing out what points are strong and which ones weak. That strategy for me worked in this case. I’ve had that article stored for 2+ years now, and finally someone comments on it.
At the same time, I agree with hunter’s (and others’) basic point, that as long as the AGW crowd are using the greenhouse as the illustration of what is happening in the atmosphere, it is fair for someone to point out the fallacies in that illustrative model. If G&T don’t do argue their science well, to me that is a different issue from ripping apart what the AGWers are selling the public.
If the illustration is wrong, people should be commenting to high heaven on the pro-AGW sites how the AGWers are misrepresenting the science.
All in all, I am glad this is out there and being discussed. I am learning from it. (which is what scienceofdoom says is the purpose of this blog in the first place.)
Thanks, everyone.
Hi Feet2thefire. You say:
I do not think the greenhouse is being used as an illustration, except possibly in a very few out of the way sites. I don’t know of any off the top of my head, but I don’t doubt there are a few, just as there are lots of sites that give poor explanations of various topics in science.
The primary information sources, however, seem to describe it perfectly accurately; without making the mistake of saying that it is the same effect as a garden greenhouse.
Don’t mistake the term “greenhouse” for using it as an illustration of how the actual descriptions of how the atmospheric greenhouse works. Most of the descriptions and illustrations I have seen — particularly the ones by major AGW expositions — illustrate the matter perfectly correctly.
Like many other popular terms in science, the actual phrase “greenhouse effect” is potentially confusing if you look at the phrase only and ignore all the associated explanations. The “Big Bang” is another such term, but I don’t think it is really a huge problem. These terms have been around for a long long time and they are not going to change. The main thing is to explain the mechanism correctly, and that is being done. Usually one of the first things you learn in atmospheric physics when this subject is introduced is the difference between a garden greenhouse and an atmospheric greenhouse.
In so far as there are any sites mixing up the mechanisms of a glass greenhouse and an atmospheric greenhouse, they invariably describe the atmospheric greenhouse effect and get the processes of the glass greenhouse wrong.
The simile is not all bad. Both an atmospheric greenhouse and a glass greenhouse work by impeding the vertical flow of heat up from the surface. The difference is that a glass greenhouse works mainly by impeding convection, and an atmospheric greenhouse works mainly by impeding radiant heat transfer.
Cheers — sylas
Silas –
Since Sagan came up with the runaway greenhouse effect back in the 1960s, I do have to ask how we separate Sagan’s concept – based on Venus – and use of the term so cavalierly in presentations that actually go well beyond the main stream media. The term is mixed in with a good percentage of articles I read, and I read very few strait MSM articles, but tend to read ones with at least some science in them. (Read: skeptical articles)
In other words, what are we to understand when the terms “greenhouse” or “runaway greenhouse” or “greenhouse gases” are used? Simply that they don’t really mean it? Or that thy are being misquoted by the journos? Or that they are dumbing it down for us mere mortals? Or are they being intellectually lazy?
You and scienceofdoom talk about the “real” scientists not believing it is really a greenhouse “effect,” but the term is all over the place. Am I being dense?
I thought G&T pointed in an interesting direction. That was based on the nearly universal use of the term greenhouse, and even more commonly used “greenhouse gases.” If it is not a greenhouse effect of some kind, what gives with the use of the term?
Oops! typo alert: 1200 years was supposed to be 100 years
Feet2theFire:
The paper was published in the International Journal of Modern Physics B in 2009.
And according to the journal – http://www.worldscinet.com/ijmpb/23/2303/S021797920904984X.html
Received 30 July 2007
Revised 6 January 2009
Perhaps you are right, they would not have been aware of it when they submitted it and perhaps their revision was due to reviewers comments and no opportunity to hastily correct the section which Trenberth and Kiehl had now “answered”.
Of course, they could have suggested the idea themselves as the method as it isn’t particularly difficult to come up with it. And they could even have carried out the analysis.
No doubt they were kicking themselves when they read the 2008 update by Trenberth and Kiehl..
sylas
“I do not think the greenhouse is being used as an illustration, except possibly in a very few out of the way sites. I don’t know of any off the top of my head, but I don’t doubt there are a few, just as there are lots of sites that give poor explanations of various topics in science.”
It is unfortunately untrue, both recent editions of “Equilibrium Thermodynamics” and “Thermal Physics” both by C J Adkins carry the old discredited version of “The Greenhouse Theory”.
Both these otherwise excellent books are firm favourites for undergraduate physics courses.
On the other hand my old school Physics textbook by Nelkon and Parker (1960)” A level Physics” had the now widely accepted proper G&T version and they also mention Wood.
Feet2theFire:
All I can say is no one who writes papers about radiative physics uses the effect of glass greenhouses to explain the effect in the atmosphere.
-Some never even mention the word greenhouse.
-Some mention it as an intro, usually with the differentiation (if relevant) that greenhouses are not a great analogy
-Some use it because it is has simply passed into common language
If the term is “all over the place” I am guessing you don’t mean in climate science/atmospheric physics papers, you mean all over the web.
“..If it is not a greenhouse effect of some kind, what gives with the use of the term?”
For myself I put it in quotes, like this – the “greenhouse” effect.
For others, it has become a handy shortcut.
For yet others, perhaps they believe the atmosphere is like a greenhouse. These would benefit from learning climate science basics. Invite them here.
But climate scientists know that the atmosphere is not like a greenhouse. It is not used as a proof.
I hear you, but it isn’t like it is in MSM articles, because I rarely read any of them, unless it is a skeptical article. I couldn’t tell you when was the last generic MSM article (meaning pro-AGW) I read.
And it isn’t usually just the term. MANY (I know, that has no sourcing, but sorry, I just can’t footnote everything I read) of them include the seemingly requisite description of “and the CO2 blocks some of the escaping infrared radiation.”
In fact, in Wikipedia at http://en.wikipedia.org/wiki/Greenhouse_effect it clearly describes the greenhouse effect in atmospheric dynamics.
And the page at http://www.ucar.edu/learn/1_3_1.htm. UCAR is sponsored by the NSF. No sourcing on this, but links to scientific papers are included on the home page.
And here is the EPE, specifically teaching this to the kids:
That is accompanied by a sketch of a greenhouse. (NO, I am not suggesting that kids are being taught serious science, but all of that is being continually PUMPED into the brains of everyone, regardless of what the “real” scientists are writing in their peer-reviewed papers.)
There is a total disconnect between the real science, as you are portraying it, and what the world is being told.
YES, scientists ARE telling the world that it is literally like a greenhouse, regardless what you all talk about among yourselves. Is it some great joke on the public?
I don’t care which is really true, whether it is literally like a greenhouse or not – but YOU scientists – should not be telling the world something you know is untrue. I know it isn’t you, specifically, but why are your brother scientists scamming the public?
This disconnect bothers me. What is literally true should be what you all are telling us, not some untrue picture of things.
scienceofdoom: Thanks so much for this site. Your efforts are appreciated.
RE: If the term is “all over the place” I am guessing you don’t mean in climate science/atmospheric physics papers, you mean all over the web.
A scholar google search of papers containing “greenhouse effect”+radiative+physics reveals a count of 13,300
A count in the thousands is too high. I concede that it’s not just the websites perpetuating the term, its the scholarly literature. We need to do better. I see Bryan’s point.
http://scholar.google.com/scholar?hl=en&q=%22greenhouse+effect%22+radiative+physics
I see Bryan’s point too. The difference is that I see it as a very small point, and one that is based not on a superior undrstanding of physics (as Bryan would no doubt have us believe) but on near total ignorance of how linguistics works.
So WHAT if the physical mechanism is radiation in the one case, but convection in the other? The fact remains that the basic effect of the differing mechanisms is the same in both cases, the one case being very common and easy to understand: hence the name, “greenhouse effect”.
Matt J.
On Tallblokes site tonight there is a prominent advocate who thinks that radiation has nothing to do with the greenhouse effect.
Yet he is happy to call it the “greenhouse effect.”
You on the other hand believe in the full greenhouse gas version of the greenhouse effect.
So it appears you are both eligible to join the “greenhouse believers club”
Matt goes on to say;
” but on near total ignorance of how linguistics works.”
Yes Matt, as clear as mud
@Bryan Your Talkblokes example is mildly amusing, but it proves nothing. As they say: “the plural of ‘anecdote’ is not ‘data'”, nor is it proof.
The overwhelming majority of people who use the term “greenhouse effect” you not share your example’s error. Even more important and relevant, though they may not understand the details of atmospheric radiative transfer of heat as well as SoD does, they do understand what your side so vehemently denies: because of the presence of GHGs, heat is accumulating, so temperature is rising, much as in a greenhouse.
Matt J. says
“because of the presence of GHGs, heat is accumulating, so temperature is rising, much as in a greenhouse.”
If it makes you feel better to believe that then fair enough.
Dont worry about difficulties like since 1998 the temperature is going down despite significant increase in CO2
Nor the fact that historically the rise in CO2 lags the temperature rise by 8oo years
Bryan,
There is no credible evidence that the temperature has been going down since 1998 unless you cherry pick the data. Even then, the best you can say is that any trend includes zero. That means both positive and negative trends are not statistically significant.
The 800 year lag (it’s probably more like 2,000 years ) is during glacial/interglacial transitions and is easily explained if you believe, as most do, that CO2 is not the primary cause of said transitions but instead acts to amplify them. ( http://noconsensus.wordpress.com/2009/06/18/explaining-ice-core-co2-lag/ ).
Another typo. EPE was meant to be EPA.
[…] on this blog (The Imaginary Second Law of Thermodynamics, How Much Work Can One Molecule Do? and On the Miseducation of the Uninformed by Gerlich and Tscheuschner (2009)) and one on another blog the subject has been much […]
The biggest question I see still remaining unanswered is, alas, too easy to classify as not relevant to the science — though I certainly believe it is.
That question is: with this many egregious errors in the science of this paper, how on earth did it survive the review process? The journal that published it , “International Journal of Modern Physics” insists that they publish only peer-reviewed papers. Or so I would interpret their words, “EM provides a full online solution for manuscript submission, peer-review, and tracking.”
That such a paper could ‘pass’ review and be published in a peer-reviewed journal cannot be good for climate science.
Matt J.
…….”That question is: with this many egregious errors in the science of this paper, how on earth did it survive the review process? The journal that published it , “International Journal of Modern Physics” ……..
You first have to prove there are ANY errors Matt.
Simply asserting there are errors or worse still quoting someone else who MIGHT have said there are errors is pointless.
The main thrust of the Halpern Groups comments seems to have been misplaced.
Gerlich and Tscheuschner have never said that a colder surface cannot radiate to a warmer surface.
I think that the paper by Gerlich and Tscheuschner has been a welcome contribution to the climate debate.
It concentrated on the fundamental science underpinning the science
The only problem is it has not been critically assessed by someone of some standing in Heat Transfer Science.
There is clearly something wrong with the consensus IPCC position.
Climate model programs are no further forward than the were 10 years ago.
Increasingly hard to accept magnitudes are given to entities like the so called back radiation.
For instance at night if we pointed a one metre parabolic mirror at a the sky we are told that we could expect it to be collecting something like 300W/m2
If the focus contained something like a 2cm2 by 5cm cylinder we would have 300,000W/m3 energy density.
Since as SoDs diagrams show plenty of 15um infra red we should see obvious dramatic physical effects.
Where are they?
Gerlich and Tscheuschner
Not true. I am not the one who needs to do it. Not when S of D and many others have already exposed the errors. By denying that this has already been done, you are simply doing just as S of D has already mentioned you do, providing nothing of substance.
G&T not only mis-state the 2nd Law in two different ways in two different places, but they completely fail to apply it correctly, failing to keep track of ALL the energy flowing in and out of the atmosphere.
Correction
The Gerlich and Tscheuschner at the bottom of the above post should not be there.
I was about to start a new paragraph, when on second thoughts, I thought it was long enough already, but pressed the post button before deleting it.
scienceofdoom
On the Miseducation of the Uninformed by Gerlich and Tscheuschner
On Having a Laugh – by Gerlich and Tscheuschner .
The names of your two threads are very apt but perhaps not for the reasons you think.
The “On Having a Laugh ” theme I thought at first was an inappropriate title.
Germans stereotypically have “no sense of humour” a bit like Spock in Star Trek.
However where to start.
Before their paper there were several versions of the “Greenhouse Effect” at least twelve I believe.
People were very free and easy about language in particular the description of infra red radiation.
Sometimes it was called thermal radiation,sometimes infra red radiation.sometimes heat radiation or even simply heat.
The publication of the paper certainly caused an uproar.
In this confusion of descriptions some people formed the idea that because G&T said “no heat can move from a cold atmosphere to a warmer surface” they meant no radiation move from a cold to a hot surface.
I was surprised by this interpretation any reread the paper to see if there was any justification for this view, I found none.
However it formed the major thrust of the comment of the Halpern Group.
Now at this time G&T could easily have cleared up the misunderstanding but they didn’t.
Gerhard and Ralf must have looked at the blogs out of curiosity
Perhaps after a hard days work with “string theory” sipping a snapps they joked about how Rabbit and friends were off in a completely wrong direction.
But since Rabbit and co were not very nice then why should G&T help them.
The events took on a comic turn when some defenders of G&T accepted the Halpern interpretation and each side went at it hammer and tongs.
I pointed out to Joel Shore in a WUWT encounter back in early March that they had an unreasonable interpretation on this point.
All G&T had to do in their reply to the comment is to ask the Halpern Group to point out which part of the G&T paper they were referring to!
However the paper,comment and reply are now there for all to read.
There has been a positive side to their contribution some diagrams have been withdrawn and text changed so that there is less confusion which is to the benefit of everyone.
However the whole episode has all the hallmarks of a Shakespearean Commedy
Sylas and I debated this issue during the gestation of the G and T rebuttal (at “all you never wanted to know about G and T”).
While he is away I will state his argument as carefully as I can, quantify it, and demonstrate that it is simply nonsensical.
Compare and contrast the bare rock earth with the atmospheric earth, all else being the same.
In the bare rock case the earth receives W watts per square meter from the sun, and radiates W watts per square meter to space. From Stefan Bolzmann, the surface temperature will be proportional to the fourth root of W, and equals 255 K.
In the atmospheric case, the atmosphere absorbs the radiation from the earth, half goes to space and half comes back. (Ignoring the minor proportion which is directly transmitted). So, avoiding the second law trap, the atmospheric earth is absorbing more energy from the sun than it radiates and will warm up until it comes into balance.
At that point it will be radiating 2W, and receiving W from the sun and W from the atmosphere. From Stefan Bolzmann, again, the surface temperature will be proportional to the fourth root of 2W. Therefore, the ratio of “atmospheric” to “bare rock” temperatures is equal to the fourth root of 2W/W, or 2, which is 1.19. This gives a temperature of 1.19 x 255K or 303K. The difference, 48 degrees C, is greater than the observed 33 degrees C, but reasonable “in view of the simplicity of the model”, to quote FWTaylor.- Elementary Climate Physics.
So what is wrong with that? Simply that it absurd to assume only one layer of the atmosphere. Depending on wavelength, infra-red radiation is absorbed anywhere between a few meters and and one kilometer.
Apply the same theory to 2 layers. The top layer must emit W to space, and W back to the first layer. The first layer must send 2W up and 2W down. The earth must warm up (again) to radiate 3W, balancing 2W from the atmosphere and W from the sun. The temperature ratio relative to the bare rock will increase to the fouth root of 3, or 335K, a temperature gain of 80 degrees C.
This is the case which Eli, et al, used in their paper, and you can read how they struggled to explain the result. But why stop there:
One layer – Fourth root of 2 = 1.19. Tsurf =
1.19 x 255 = 303K
Two Layers – Fourth root of 3 =1.315 T surf = 1.315 x 255 = 335K
Three Layers – Fourth root of 4 = 1.415 Tsurf = 1.415 x 255 = 360K
Four Layers – Fourth root of 5 = 1.495 Tsurf = 1.495 x 255 = 381K and so on.
These results are, as I said at the beginning, absurd.
But for those who prefer the “my brother is bigger than your brother” style of argument, you can find the same analysis set as a problem in a First Course in Atmospheric Radiation, page 252, by Grant W Petty, University of Wisconsin Madison, mentioned above.
More convincingly, one of the co-authors of the rebuttal, Chris Coloose, reached the same conclusion recently at Real Climate:
“This is one of the problems I have with the simple layer model as it is introduced in some textbooks, such as Dennis Hartmann’s or David Archer’s “Understanding the Forecast.” This is where you simply add up the influence from successive blackbody “layers” with a final result of something that usually ends up looking like T_s=T_eff*(N+1)^0.25, where N is the number of layers, and T_s and T_eff are the surface and effective temperatures, respectively. Archer discusses some of the incompleteness of this model in his class lectures (lack of convection, layers are not fully transparent in the shortwave nor fully opaque in the longwave) but I think the whole presentation misses the point completely”
scienceofdoom
You say
Clearly conductivity is the least important of means of heat transfer in the atmosphere.
I would not be so dismissive of conduction.
The air particles on hitting the Earth Surface leave with a temperature characteristic of the surface.
The air particles speed up, in other words their temperature increases, the hotter air is less dense than colder air above and hence moves up (convection).
So convection in the atmosphere is caused mainly by conduction at the surface, so they must have approximately the same magnetude.
scienceofdoom
You say
“But many people are confused and say we can’t because 50% of the solar radiation is “infrared”. Infrared means >0.7μm. Conventionally, climate scientists use “shortwave” to mean radiation 4μm. As less than 1% of solar radiation is >4μm this is a very useful convention. Any radiation greater than 4μm is terrestrial (to 99%”
If you had read the title page of the paper
‘Falsification of the Atmospheric CO2 Greenhouse Effects Within the Frame of Physics’ by Gerlich & Tscheuschner
Notice the part
Within the Frame of Physics
Open any Physics text book and you will find that
Infra Red occupies all wavelengths longer than visible red but not as long as microwaves of wavelengths 1mm.
So once again as usual G&T are correctly reporting from within the framework of physics
No, Bryan, that conclusion does not follow. Nor is is true. Rather, as S of D has already shown, G&T do NOT “report from within the framework of physics”.
Nor, for that matter, are atmospheric scientists departing from that framework by using their own language ‘longwave’ and ‘shortwave’ to make the handy distinction. You are clearly merely quibbling, using such piffling matters to hide your own refusal to follow the real physics.
scienceofdoom
You say
…..”Radiative Balance and Mathematical Confusion”…..
This theory is also known as “Radiative Equilibrium”.
Implying that dire consequences will flow if not strictly adhered to.
As Lindzen ha pointed out recently;
There has been a rise of about 0.7 degrees C over the last 150 years.
Lindzen commented on this and says radiative equilibrium is seldom observed.
He will notice that the Earths temperature is always changing hence the Earth is generally out of balance.
The well documented “Medieval Warm Period” and the “Little Ice Age” shows the change.
scienceofdoom
You say
…..” And the atmosphere in turn radiates energy in all directions – one of which is back to the earth’s surface. Believers in the imaginary second law of thermodynamics don’t think this can happen. And this is possibly due to the miseducation by our intrepid duo”….
I notice that you have not endorsed the Halpern interpretation fully.
You have left it the question slightly open.
Now is your chance to go to G&Ts paper and see if you can find any evidence to support your implication.
If you cant then a major rewrite of several sections would be indicated
But despite your denials, he HAS already done this. So has diessoli. The result is that the G&T paper cannot be fixed with a mere “major rewrite”. It has to be thrown out entirely. It should never have even been accepted for publication at a refereed science journal.
Matt J.
You were challenged to come up with a quote from the G&T paper to substantiate the last misquote you gave.
You failed.
Now you are hiding behind diessoli’s false claim.
If that’s the best you can do you must have that sinking feeling of having lost the argument.
The rewrite I was writing about was some of SoDs threads.
The G&T paper as far as I know has no errors whatsoever.
diessoli’s claim was not false, I have no such sinking feeling.
Matt J.
….”You are clearly merely quibbling, using such piffling matters to hide your own refusal to follow the real physics.”….
I would tend to agree with the above quote, however it was SoD who thought the matter of some importance.
G&T were using the traditional Physics definition of the Infra Red.
SoD thought that by doing so G&T were deliberately misleading people.
If you had a physics background you would know that G&T were correct.
I laugh, Bryan. If you must go out on a limb like that, at least refrain from cutting off the limb you are on!
I do have a physics background. What is more, I aced this very topic, thermal physics, in my junior year, even applying the mathematics of category theory to come up with an improved version of “the thermodynamic square”, which contributed to my high grade for that class.
To be sure, my memories of the topic have faded since then, but yes, you really did saw off the limb you went out on by boldly claiming I had no physics background.
Why, if we are to judge by postings here (and we really have nothing more to go by), then despite your claims to a degree, YOU are the one we would have to say shows no physics background. Especially when you claim there are no errors in the G&T paper. Too many real practicing physicists have found the errors you blindly deny are there.
But this forum is not for discussing vain accusations against others’ backgrounds. It is for discussing the physics of global warming aka climate change. You know this, yet you regularly ignore it anyway. But worse yet, when S of D DOES bring you back to the physics, you immediately get evasive, don’t answer the immediately question, and go off on yet another tangent, leading us down another rabbit trail.
You did this recently when he corrected you concerning the absorptivity/emissivity of the Earth’s surface in the far IR — as you have done many times before on related but different subtopics. Or did I miss a post in which you admitted that your previous insistence that “a lot” of backradiation is scattered is pure buncome?
Such behavior does not say good things about your character, Bryan.
Bryan:
I think you have excelled yourself this time.
Gerlich and Tscheuschner had said:
Why is it important and why does ignoring it make any difference to anything in climate science?
But congratulations on knowing the definition of infra-red. You’ve made my day.
scienceofdoom
I don’t mean to be polemical.
I think you like me are trying to make sense of what the climate is doing.
I try to insist on using the correct definitions in a technical exchange such as this.
It would be a reasonable point of view to say that there is not a lot that divides us.
The loose usage of definitions can obscure a rational outcome to these exchanges.
You must remember I will see things from a Physics viewpoint.
Since Physics is the fundamental science and the various sciences rest on the conclusions of fundamental laws I cannot depart from these building blocks.
By the way did you notice the comments by Fred Staples above.
You are to be congratulated on hosting the website where the exchange of viewpoints seems to be attracting heavyweight comment.
But you are being polemical. Very polemical. So if you are really telling the truth when you say you don’t MEAN to do this, you have got a lot of self-examination to do, to see why the gap between what you mean and what you do is SO huge.
Then maybe, just maybe, you will finally really get back to the real physics instead of the peculiar mix of error and evasion we have seen to date.
Matt J.
…..”I do have a physics background. What is more, I aced this very topic, thermal physics, in my junior year,”…….
What made me think you did not have a background in Physics is when you appeared to find fault with G&Ts traditional physics definition of Infra Red Radiation.
Further Matt you have failed to substantiate any claim you have made about any so called errors in the G&T paper.
You may have thought that, but you were wrong. You still are wrong. Why, the real cause of your error can only be your own inability to READ.
How so? Because you claim to find evidence that I found fault with their DEFINITION of IR. But I never wrote any such thing. It is their evaluation of the SIGNIFICANCE of IR I find fault with — as do many with more physics education than I have.
If you were both honest and educated, you would admit as much by now, instead of repeating this obviously false claim that there are no errors in the physics of G&T.
SoD and Matt J.
G&Ts statement about Infra Red is almost exactly the same as wikipedia
Infrared radiation (IR) is electromagnetic radiation with a wavelength between 0.7 and 300 micrometres, which equates to a frequency range between approximately 1 and 430 THz.[1]
Its wavelength is longer (and the frequency lower) than that of visible light, but the wavelength is shorter (and the frequency higher) than that of terahertz radiation microwaves. Bright sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation.[2]
http://en.wikipedia.org/wiki/Infrared
G&T therefore were obviously within the framework of Physics, why not join them.
Once again, your conclusion does not follow. Not at all. G&T are not “in the framework of physics” just because they managed to get the definition of IR right.
Especially not when, even in the same statement where they get the definition right, they completely miss the significance: despite their petty, whining objection, IR in direct radiation from the Sun is an small part of the Earth’s energy budget.
This is well known — even if you and G&T do not know it yet.
Bryan:
It’s absolutely fabulous that G&T are correct about the definition of infra-red.
They should be commended on this master-stroke and I can see now why their paper was published.
But one small question remains. The question I asked in the article and asked again when you reminded me of their master-stroke in reproducing a definition.
Gerlich and Tscheuschner had said:
Note that I haven’t yet found an atmospheric text book that has any confusion about the definition of infra-red, although no doubt most expect the readers to know the definition.
The question – Why is it important and why does ignoring it make any difference to anything in climate science?
scienceofdoom
In your introduction above you are sujjesting that G&T in giving a straitforward explanation about solar radiation are missleading people
Solar Energy Breakdown and A Huge Success in Miseducation
This was the headline of your section.
Perhaps a rewrite is in order.
You say
“The question – Why is it important and why does ignoring it make any difference to anything in climate science?”
But if you check you have answered it yourself
“Many uninformed people who have become miseducated are certain that much solar radiation is >4μm – possibly due to confusing infrared with longwave.”
Corrected for spelling
scienceofdoom
In your introduction above you are suggesting that G&T in giving a straightforward explanation about solar radiation are misleading people
Solar Energy Breakdown and A Huge Success in Miseducation
This was the headline of your section.
Perhaps a rewrite is in order.
You say
“The question – Why is it important and why does ignoring it make any difference to anything in climate science?”
But if you check you have answered it yourself
“Many uninformed people who have become miseducated are certain that much solar radiation is >4μm – possibly due to confusing infrared with longwave.”
Bryan said above, in a comment on May 24, 2010:
You cannot focus backradiation. Think about it. Backradiation comes from the sky. This is not a point source. There’s nothing to focus. The numbers are not “Increasingly hard to accept magnitudes”, but the DATA that any theory must deal with. A theory that cannot accept those magnitudes is one that has been falsified, so it is your theory that must be wrong. In this case, it is your theory of focusing that is incorrect.
There is a hard limit on what energy density you can get by focusing ANYTHING. You cannot focus even the Sun to get the energy flux as high as you like, since it is not a point source. With the whole sky as your radiation source, there’s no focus possible. A parabolic mirror works with radiation all coming in about the same direction, but that doesn’t apply with backradiation.
The second law ensures that thermal radiation from any source at a certain temperature cannot be focused to give a higher temperature. If you COULD use your mirror to focus in the way you describe, then would be able to violate the second law. This applies just as much for the Sun (which as far as radiative energy is concerned just like radiation from a ball of gas at about 5780K) as it does for radiation from the atmosphere (which is colder than the Earth’s surface).
With the atmosphere, the energy is certainly there and has been directly measured. I gave a reference before:
Stern, S.C., and F. Schwartzmann (1954) “An Infrared Detector For Measurement Of The Back Radiation From The Sky”. J. Atmos. Sci., 11, 121–129. This obtained values in Maryland, and they were in the range 314 to 405 (daytime) and from 206 to 312 (nighttime), limited to clear sky conditions. In modern times the measurements are much more precise and confirm the same kinds of magnitudes. This observed data, people. It’s not speculation or invention. Backradiation is directly measured and observed, and the radiant energy received at the surface from the atmosphere is about twice what is received by direct radiation from the Sun. But it is a cooler lower frequency radiation, from the whole sky, and you therefore cannot focus it, or use it to power an engine, because the surface is hotter than the atmosphere, and radiates up into the atmosphere a still greater amount of energy.
The measurement of backradiation is not in any credible question. What you need is simply a bit more basic physics to understand what is wrong with the proposed parabolic mirror idea as a criticism.
As a side note, you are using very strange units. If you really mean energy density, this would be J/m^3. Another widely used unit is W/m^2, which is rate of energy flow in a given direction, per unit area. The two are closely related in case of electromagnetic radiation, with “c” as a constant of proportionality. To speak of W/m^3 makes no sense.
You ask about dramatic effects… we DO see dramatic effects. For example, we see the surface of the Earth radiating one heck of a lot more energy upwards than there is coming from the Sun. That should be plenty dramatic enough for anyone!
Sorry this response took so long… I have limited net time at present, since I am in Korea.
Cheers — sylas
Sylas the post was a shorter version of one replying to scienceofdoom on another thread when I thought he was suggesting that backradiation actually heated the Earth Surface.
You pointed to the abundant quantities of 15um infra red in backradiation to support your position.
I tried to come up with an explanation of how this radiation could be absorbed and yet show no heating effect. – it was not easy.
I gave an answer that radiation centred around the lower temperature from the colder object would find the radiation from the hotter object streaming out at a higher rate.
I was not particularly satisfied with my own answer.
So I reversed the burden of proof back to believers in AGW to show why at night 300W/m2 backradiation focused by a one square metre area parabolic mirror would not show dramatic physical effects.
I had two excellent replies from Alexander Harvey and Nick Stokes.
They pointed out independently that;
1. Backradiation is diffuse and cannot easily be focused which I should have remembered.
2. More importantly a source cannot increase the temperature higher than its own temperature.
So the night sky at say -20C cannot raise the temperature of the surface to more than -20C.
I feel that this explanation is much better than the one I was fumbling about with.
I think that you are saying much the same.
Thanks for the reply.
Did you notice that Fred Staples has addressed a comment to you above.
Hey Bryan,
Glad we are on the same page then… or at least some of the same page. 🙂
I am not able to read all the threads here so I can really only reply to what I see in this one. I’m glad to hear Nick Stokes is engaged… what I have seen of his writing seems very good at keeping things focused on the subject and away from the persons, which helps.
I guess critical points I would like to emphasize — without presuming whether you or anyone agrees — are as follows.
(1) The Earth’s atmosphere supplies backradiation to the surface with magnitudes of substantially above 300 W/m^2 as a global average, and hence substantially more than the energy given directly from solar radiation.
(2) This backradiation is there because the atmosphere is able to emit and absorb thermal radiation.
(3) Not all gases emit and absorb thermal radiation. Those that do are called “greenhouse gases”; not because they stop convection like a glass greenhouse, but because they absorb radiation for the atmospheric greenhouse.
(4) Without the greenhouse gases, the surface of the Earth would be far colder than it is at present, since it would only need to be hot enough to radiate what it absorbs from the Sun. The Earth’s natural greenhouse effect keeps our climate at a nice livable above freezing temperature.
My reply to Fred is posted, but it has more links and hence needs to pass a moderation check before it will appear in the thread.
Cheers — sylas
You claim a physics degree, yet you manage to come up with THIS? But failure to understand the physics is all over your post.
Most noticeable is how you quote Alexander and Fred, yet go beyond what they said, to something that is NOT in the physics.
No, it is NOT true that “So the night sky at say -20C cannot raise the temperature of the surface to more than -20C.” Nor does that really follow from what Alexander and Nick said. That WOULD be true if the night sky were the ONLY heat source, but that is obviously not the case. So the night sky is not doing all the heating, it is only slowing down the flow of heat OUT from the surface.
This has been explained to you how often now?
Hello again Fred! I’m not exactly back, but I am dropping in, writing from a hotel in the small hours of the morning to clarify a point or three. Fred Staples writes in a comment on May 27, 2010:
Just to clarify, the argument Fred describes here is not one I have discussed with him before. The link to where Fred and I have engaged is actually: A burrow project? Note that I was using my blogger account, which lists me as “Duae Quartunciae”, which is my blog. I have since fixed it to identify me as “sylas”.
The other thread Fred mentions is All you never wanted to know about Gerlich and Tscheuschner, in which I had no part.
I am very familiar with the argument Fred describes, and we do use it in the rebuttal of G&T (section 2). (I was not strongly involved in writing that particular section, though of course all the co-authors were involved in the internal review and editing of everything.) Where Fred goes wrong is to misunderstand the role of the argument. This is not a model of the Earth! The point of the argument is to use the simplest possible example of an atmospheric style greenhouse effect (as opposed to the convective effects of a glass greenhouse) so as to show that surface temperatures ARE greater with no violations of the second law involved.
To point out differences with the Earth misses the whole point. This is a demonstration of a really simple and trivial to compute model that unquestionably gives a warmer surface by virtue of a greenhouse effect. The example is supremely simple — much simpler than the Earth — in order to expose more clearly the errors in Gerlich and Tscheuschner’s assertions about second law violations.
I am still unsure whether or not Fred recognizes that Gerlich and Tscheuscher are flatly wrong to speak of second law violations in ANY of the descriptions of the atmospheric greenhouse effect. But that’s okay. I do not mind helping to explain this as best I can, and whether I am able to help people follow this or not, I remain 100% positive that the errors in their paper, repeated in their “reply” to our rebuttal, will mean that the paper will continue to have no effect whatsoever on the progress of climate science or the basic descriptions of atmospheric thermodynamics used in teaching undergraduates. If anyone does come to understand the greenhouse effect, that should involve not just reading my posts, but checking further with other references — especially basic texts in atmospheric physics.
One of the ways some people can be helped to grasp how a greenhouse effect can give a warmer surface is a very simple case — far simpler that a real atmosphere — in which you have isothermal layers that are completely opaque to infrared thermal frequencies and completely transparent to shortwave solar frequencies. This simple model can be used with high school level physics to show how you get a spontaneous rise in temperature with additional layers, all with no violations of any laws of thermodynamics.
There are a number of correspondences between this kind of model and a real atmosphere, although they are limited. The criticisms Fred makes are irrelevant, because they treat this as if it was intended to represent the Earth directly. The last paragraph of section 2 in our paper reads as follows:
Clear yet? The simple slab model is a very basic high school level example to show the fundamental errors in Gerlich and Tscheuschner’s claims. To actually model the Earth, you would use many more layers, and have each layer blocking only a tiny fraction of the radiation passing though it. (That is, a layer representing a small slab of real air) The model would have to consider in more detail the absorption and emission as a function of frequency. The model would also have to consider the flows of energy between layers by sensible heat flow; which is convection and latent heat. Conduction is negligible. It is, in fact, a great big numerical integration problem.
None of these additional complications required in a real atmosphere introduce anything to violate the second law. The incorrect claims by Gerlich and Tscheuschner concerning alleged violations of the second law are very general, and are easily shown to fail using the much simpler case of a couple of isothermal layers totally opaque to thermal radiation.
Cheers — sylas
Matt J.
Why do your comments not follow the normal time sequence.
They pop up all over the place like kind of inserts.
Are you and SoD possibly related?
Bryan, note that I answer here after Matt, by time, and yet my post will appear in front of his in the sequence. This because I used the little link called “reply” to post this, rather than the post box at the bottom.
Matt is using a standard feature of this commenting system to keep his responses adjacent to the message to which he is responding. You can identify such “replies”, by an additional indentation level. You should see it in this reply, but absent in Matt’s reply below.
I do this as well, sometimes. It is often a useful feature for keeping semantically consecutive comments together.
Cheers — sylas
The feature is more useful in other environments, such as NNTP read with the newsreader ‘trn’. That would allow you to display posts either by thread OR by date.
Why WordPress does not support this, or why (if it is supported) it is not enabled in this blog I do not know.
Bryan-
Why do you keep asking irrelevant and misguided questions? What “normal time sequence”? They show up as replies. You really should figure out how that works before posting again.
Hi Feet2thefire,
This is a very late reply to your comment above dated May 9. I did see your comment but have kept answering other stuff. Sorry for the delay!
The underlying physics applied to planetary atmospheres gives different results because of different conditions. Venus, for example, is nearly all CO2 in the atmosphere, with more solar radiation received, but actually LESS absorbed than Earth because of the high albedo on Venus. Venus maintains a higher temperature with less energy. emitted from the planet itself. But it is still all the same physics.
The phrase “runaway” refers to a particular kind of supercritical feedback, which would have occurred on Venus as any oceans were being boiled away. The extra water gives a stronger greenhouse effect which then ramps up the surface temperature even more.
We have positive feedback on Earth as well, but not runaway feedback. The difference is very important. The positive feedbacks on earth are less than the basic negative feedback associated with the base Planck response, and so the climate is stable, not runaway.
This is really just a case of understanding the terms. It can take a while to do this, and a really good approach is to find some college level texts for undergraduates, in atmospheric radiation physics. This will often show how the same thermodynamics applies on Venus, and on Earth, and usually some other planets as well, such as Mars or the Moon with no atmosphere at all. Sagan’s work on Venus continues to be important foundational work for explaining how Venus came to be the way it is.
Cheers — sylas
scienceofdoom
You say
…..”They take many other snipes at climate science by the approach of pointing out a term or dependency has been “neglected” (for example, like conduction through the atmosphere) without showing that the neglect has a significant impact – except in the case of conduction where (unwittingly?) they appear to show that conduction should definitely be ignored!”……
I don’t know what you mean by this paragraph.
Could you explain?
You will have to forgive sceptics, Sylas, (May 28th) if we assume that you mean what you say and that your models are meant to be taken seriously. After all, the object of the exercise, on which multi-billion dollars/pounds are being spent, is to find a coherent explanation for the warming of the atmospheric earth relative to a bare rock earth.
Only then will anyone be in a position to assess the impact of increasing CO2 concentrations, on which even more multi-billions will be expended.
It was (I believe) the suggestion that back radiation from the atmosphere could directly warm the surface that originally irritated G and T. Here, for example, is Barton Paul Levenson over at RC:
“Your CO2 absorbs an infrared photon, one of its electrons jumps a level, and it either radiates another photon of the same level, or more likely, crashes into a nearby nitrogen or oxygen molecule and transfers some of the new stuff as kinetic energy. Temperature is a measure of kinetic energy at the molecular level; the faster the molecules jiggle, the hotter the object. Thus the atmosphere warms up. Those collisions transfer energy *back* to the CO2, which radiates by the (wavelength-specific) Stefan-Boltzmann law. Some of the energy goes back down to the surface and heats it above what it would be from sunlight alone”.
Mostly nonsense.
Here is FWTaylor, Elementary Climate Physics:
“ However, the flux from the atmosphere occurs in both the upward and downward directions, and so, in equilibrium, the surface receives a second contribution equal to that from the sun, raising its temperature to 303K.”
More nonsense.
You say, Sylas, that all you wished to demonstrate with your multi-layered model of the earth’s atmosphere was that the temperature of a heat source will increase if it is insulated.
Even with that modest, self-evident, objective, your model must conform to first principles. You must balance the energy flows both at the surface and at the top of the atmosphere, (First Law), and you are not allowed any direct warming from the back-radiation (Second Law). To do that you will need a multiple layer model. Why?
Because most of the surface energy transfer to the atmosphere depends on convection and evaporation (latent heat – 75% of the surface is water). Radiative heat (net energy) transfer to the atmosphere must be a relatively small proportion of the total. But the atmospheric earth, at 289K will be radiating far more energy than the bare-rock case (396 Watts per square meter against 239), and receiving far less, so the back-radiation must equal most of the outgoing radiation. But, at most, any one layer of the atmosphere can emit only what it receives, and only half of that can return to the surface. So, to achieve a surface balance your model must have multiple layers, and if that is the case the calculated surface temperature will be absurdly high.
For example, the bare rock earth at 255K radiates 239 watts per square meter. The atmospheric earth receives about 50% of the bare rock input, and most of that is transferred to the atmosphere by convection and evaporation. If only 40% of the net input energy is radiated, the net radiative output (outgoing less back radiation) can be only 48 watts per square meter, and the back-radiation must, consequently, be 348 watts per square meter.
Assuming that 50% of the absorbed radiation in each atmospheric layer is radiated down, and 50% up, the up to down ratio for a single slab atmosphere is 2:1. Relative to the bare rock case, the outgoing energy doubles, to 478 watts per square meter, and the temperature increases by the fourth root of 2 to 303K. But the energy balance requires an up to down ratio of 1.13 to 1. Every additional atmospheric layer we assume changes the up to down ratio in the sequence 3 to 2, 4 to 3, 5 to 4 etc. Between 8 and 9 layers gives us the ratio we need.
Sadly, it also gives us outgoing radiation of 1912 Watts per square meter, and a surface temperature of 433K. Only the top layer radiation and temperature, 239 watts and 255K is correct.
If we want a plausible explanation of the “greenhouse” effect, we must look elsewhere – to the lapse rate, as a matter of fact, a phenomenon which depends on gravity (compression) and convection, and which has nothing to do with radiation.
Here is Ray Pierrhumbert at RC:
“In a nutshell, then, here is how the greenhouse effect works: From the requirement of energy balance, the absorbed solar radiation determines the effective blackbody radiating temperature Trad. This is not the surface temperature; it is instead the temperature encountered at some pressure level in the atmosphere prad, which characterizes the infrared opacity of the atmosphere, specifically the typical altitude from which infrared photons escape to space. The pressure prad is determined by the greenhouse gas concentration of the atmosphere. The surface temperature is determined by starting at the fixed temperature Trad and extrapolating from prad to the surface pressure ps using the atmosphere’s lapse rate, which is approximately governed by the appropriate adiabat. Since temperature decreases with altitude over much of the depth of a typical atmosphere, the surface temperature so obtained is typically greater than Trad, as illustrated in Figure 3.6.
Increasing the concentration of a greenhouse gas decreases prad, and therefore increases the surface temperature because temperature is extrapolated from Trad over a greater pressure range. It is very important to recognize that greenhouse warming relies on the decrease of atmospheric temperature with height, which is generally due to the adiabatic profile established by convection.
The greenhouse effect works by allowing a planet to radiate at a temperature colder than the surface, but for this to be possible, there must be some cold air aloft for the greenhouse gas to work with.”
I’m not sure which is the more appropriate expression, Mr. Staples, for your achievement here: “tempest in a teapot” or “mountain out of a molehill”.
Your objections are mostly quibbling. You grossly over-exaggerate the inaccuracies of the models whose conclusions you don’t like.
So, for example, you complain that Barton Paul Levenson’s explanation is “mostly nonsense”. But this is FAR from the case! On the contrary: there are only little bits that are nonsense, such as his bit about temperature being a measure of kinetic energy (it isn’t: it is the partial derivative of entropy wrt energy: but since entropy is a pure number, of course it has the units of energy).
But most of the rest of his explanation is sound. Some of the energy, the famous “back radiation” really DOES come back to Earth, and it really is absorbed and converted into heat, only some of which is then re-radiated.
This is no more a violation of the 2nd Law then Feynmans example (Ch. 44 “The Laws of Thermodynamics” in Vol IV of the Feynman Lectures 1965) of friction heating the hotter object: it is heat transfer BY ITSELF from colder to hotter that the 2nd Law forbids. But this is NOT “by itself”: it is driven by energy and entropy coming from the Sun, accompanied by changes of state in both Earth and atmosphere.
Matt J.
Barton Paul Levenson
…“Your CO2 absorbs an infrared photon, one of its electrons jumps a level, and it either radiates another photon of the same level, or more likely”…….
Sylas assured me that there was no one in the AGW camp who believed such nonsense.
Matt you don’t need to involve Feynman here;
“The Laws of Thermodynamics” in Vol IV of the Feynman Lectures 1965) of friction heating the hotter object
Count Rumford noticed this in 1798 while boring the barrel of a cannon
“However, Rumford’s most important scientific work took place in Munich, and centered on the nature of heat, which he contended in An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction”
Force times distance gives work done.
The heat produced caused an increase in temperature of the cannon and drill.
All perfectly well understood (for at least 150 years)and fully in accordance with the Second Law.
Bryan-
You SAY “perfectly well understood”, yet you deny the implications every single time you deny that backradiation could heat the Earth.
Hi; sorry to be a “Johnny come lately”, but I just ran across this exchange while looking for information on G&T.
Some comments: precision of language is really important in such a discussion. It is difficult to follow discussions that use non-technical terms like “heat” (or its predecessor “caloric”), or loose definitions of “work”. Substitution of delta S = Q/T is demonstrably wrong! Calling blue light infrared radiation is jolting to an old infrared spectroscopist.
After teaching thermo for decades, my choice of terminology is given on my website (:Intro. to Thermo). Based on written comments, it appears the “new” definition of the “greenhouse effect” is the same one we used 60 y ago, which was refuted by Wood. I’ve had problems finding G&T in printable form; it is obviously a travesty, but I can’t figure out, from the discussions, what they said that is wrong!
Hi Robert. What Wood proved concerns how a glasshouse works. The transition of radiation is through glass doesn’t have much effect; a glasshouse works mainly by preventing heat loss by convection of air.
Wood’s work does not have any relation at all with the atmospheric greenhouse.
The main implication of Wood’s work is that the physical processes of a glasshouse and of the atmospheric greenhouse are different. They both work by blocking vertical heat flows, but the glasshouse works mainly by blocking convection and the atmosphere works mainly by blocking thermal radiation. This is well understood, and has been understood for years.
The main thing where Gerlich and Tscheuschner are wrong is in their claims that anything about conventional descriptions of the atmospheric greenhouse effect involve any kind of violation of the second law of thermodynamics. They claim to “falsify” the greenhouse effect. This is nonsense. The atmospheric greenhouse effect is a perfectly natural and inevitable thermodynamic consequence of greenhouse gases in an atmosphere — that is, gases which are mostly transparent to solar radiation but opaque to thermal radiation.
Cheers — sylas
Robert Bauman:
You can download their paper here – http://arxiv.org/pdf/0707.1161v4
The page it is linked from is – http://arxiv.org/abs/0707.1161
In atmospheric physics, greenhouses are not a part of the development of the theory. When the atmosphere absorbs longwave radiation but is almost transparent to shortwave radiation it is quite different from a greenhouse.
Anyway, I look forward to your comments.
And what do you mean “Calling blue light infrared radiation is jolting to an old infrared spectroscopist” – clearly blue light is not infrared, no argument from me.
Did you find this somewhere in the article?
Sylas, June 22nd, the Woods experiment was not designed to find our how a greenhouse works. It was, as Mr Baumann says, designed to test the then current theory of atmospheric radiation which you can still find on the internet and on Page 18 of John Houghton’s Global Warming (complete with a “back-radiation” diagram in a greenhouse).
Woods did this by building 2 greenhouses, one of glass and the other of rock salt.
The first absorbed infra-red radiation from the interior; the second did not. Woods was looking for a difference in their interior temperatures which would have confirmed the “W in, 2W radiated from the interior, W back from the glass, W out” radiative greenhouse theory. It was not there.
G and T ask all global warmists to discuss this experiment. Few do. One explanation was provided by SD Silverstein in 1976. Working only from heat transfer equations (which he saw no need to test by measurements) he concluded that radiative absorption must have heated the glass above the temperature of the rock-salt. However, this higher temperature increased the rate of convection from the exterior surface, balancing the energy flows without an interior temperature increase.
This is plausible, and the radiation to space from a marginally warmer atmosphere might produce a similar result.
Thermodynamics has been deeply troubled from its beginning by problems of nomenclature. Major advances in understanding were contributed by Lavoisier, Rumford, Black, Joule, etc. up to the present, but the inconsistency of nomenclature makes all of these hard to interpret (even where they are wrong). If you choose to use “heat”, for example, no one can prove you are wrong, because no one can know what YOU mean by the term. Good terminology can help.
But there is a deeper problem on climate change. What most of us cannot do is check the experimental numbers quoted so freely in the literature. By choosing quoted experimental numbers I could prove either group is right, or wrong. Experiments always top theory, if the experiments are done carefully and quoted correctly. And least significant is the “they made lots of errors” argument. Each writer seems to believe he understands the truth but cannot, or will not, say where G&T are wrong.
Does anyone disagree that T leads CO2 by 800 y? Does anyone who disagrees with G&Ts arguments on the second law understand the second law well enough to say what it does mean?
The latest quote, (by Silverstein?; but not the worst) has the ground radiating more (of something) than it receives; now that is crazy! So far the anti-s have a better argument than the pro-s, but it is hard to find any pro argument that makes sense. (I am NOT suggesting that writers of thermodynamics texts generally do a better job of sorting out nomenclature accumulated over two centuries plus. What I wrote 45 y ago needs correcting. See Rev. Ed., and “Why Things Happen”, at ). It’s no fun knocking down strawmen.
RPB
True, the nomenclature has been muddled from the beginning. But that is no excuse for the misunderstandings G&T’s paper relies on.
Let’s take your example, ‘heat’. Of course, the early workers did not know it could be expressed in terms of kinetic energy, so their definitions had to be what my high school chemistry teacher called “operational definitions”. Given that limitation, they did pretty well.
Nowadays, we have no excuse for forgetting that heat is a form of energy transfer rather than energy ‘storage’. And if we still use one of the older operational definitions at any time, we should make it clear that that is what we are doing, rather than allow the reader/student to confuse the modern definition with the old.
But I cannot agree with you that simply using the term ‘heat’ allows you to get away with anything and escape refutation. Nor can it rationalize the heaps of garbage G&T have passed off as ‘science’, as ‘scienceofdoom’ has already exposed them for doing.
This brings me to my main point: it is even more shocking to claim that G&T has not already been refuted, especially when the post making the claim is itself attached to the article that details many of the even more numerous scientific errors G&T made in their paper.
Finally, yes, we DO disagree that “CO2 leads temperature by at least 800 years”. That generalization may have held well throughout most of prehistory, but we now have very good reason to believe that man-made intervention in the carbon cycle invalidates the generalization: now it can lead by a much shorter time.
Fred Staples:
It’s probably a very interesting experiment.
But it seems amusing that this experiment is a reason for doubting the inappropriately-named “greenhouse” effect seeing as we can measure the actual effect directly.
As shown at the end of the article above.
Many people would like G&T to discuss this radiation, where it comes from and what happens to it when it is incident on the ground.
So far G&T have not been forthcoming.
Robert Bauman:
Well, I don’t know what you are reading. But this comment is quite confused in so far as the real science is concerned.
We could look at a typical case or the global annual average case.
You can see a typical case in Sensible Heat, Latent Heat and Radiation.
For the estimated global annual average the solar radiation absorbed by the ground is approximately 170 W/m^2 and the radiation from the atmosphere is approximately 320 W/m^2.
The ground radiates out around 390 W/m^2.
The ground is receiving more than it radiates out. The balance is carried away by sensible heat and by latent heat. And so the energy in is equal to the energy out.
Averages confuse some people because they are not any one place and time, but they are drawn from all of the measurements from the many locations around the world.
There is nothing particularly mysterious or difficult about the subject.
Point an instrument which measures radiation from 4um-100um up at the sky from outside your house and you will find that there is significant radiation from the atmosphere.
I think one of the main reasons averaging confuses people here is that climatologists are averaging across time periods where the directions and quantities of heat/energy flow are very different, e.g., day and night. I would love to see a coherent presentation of all the different energy flows for midday and midnight. Surely that would be much more clear.
Robert Bauman:
…”I’ve had problems finding G&T in printable form; it is obviously a travesty, but I can’t figure out, from the discussions, what they said that is wrong!”……
Robert after looking at your website and comments above, it is clear that you will be able to make an informed contribution.
Perhaps after reading the paper you will find that you are substantially in agreement with them.
That fallacy, Bryan, shows how thoroughly unscientific your attitude to the entire debate really is. It is worse than mere idle speculation to speculate that he might agree. Especially after Science of Doom already HAS read the G&T article, and has found SO many flaws in it, as he has detailed in the article to which you append your speculation.
Matt J.
….”Especially after Science of Doom already HAS read the G&T article, and has found SO many flaws in it.”….
Robert will find that one of the non errors that SOD found was G&Ts definition of the Infra Red Spectrum.
When I pointed out to SOD that G&Ts version was almost exactly the same as in Wikipedia, SOD conceded the point but with a sarcastic reply.
I think that Robert has the background to look at these so called “errors” and come to an informed conclusion.
Perhaps after reading the paper he will find that he is substantially in agreement with G&T.
But that, Bryan, is another example of the fallacy of irrelevant detail. You zeroed in on the definition of infrared not because it was relevant, but because you thought you could win cheap debating points. You failed, which is why you got the sarcastic reply.
All informed conclusions concerning the G&T paper are essentially the same: that the paper completely fails to do what it claims to do, it completely fails to disprove AGW. It does not even cast reasonable doubt on it — no matter how hard you strain to make the doubt look reasonable.
Matt J
…”.You zeroed in on the definition of infrared not because it was relevant, but because you thought you could win cheap debating points”…….
No Matt, I zeroed in on the definition of infrared because SoD thought that this definition was an error and was intended by G&T to mislead people.
See above SoDs article paragraph
“Solar Energy Breakdown and A Huge Success in Miseducation”
and my comment on 27th May.
Bryan-
You have several comments on that date. Not one of them correctly corrects Science of Doom, whose paragraph on the Solar Energy Breakdown is correct.
Matt J
I would invite readers to look at the dialog between SoD and myself and form their own conclusions.
One hallmark of a sceptic is that they search for the truth.
If they find themselves in error they thank those who point out their mistake and correct their outlook on a topic.
One aspect of an AGW advocate is the terrifying prospect that if they admit to the slightest mistake then the whole edifice of their fairy tale will come crashing down around them.
I already did. The conclusion I reached was that either you have no clue what you are talking about, or you are deliberately evading the truth in order to prop up the lie that AGW does not exist.
Bryan said:
What did G&T say?
And so I said, in the article:
Hats off to Bryan for missing the point.
Were Gerlich and Tscheuschner correct about the definition of infrared radation? -Yes.
Was that my point?
-No.
Were Gerlich and Tscheuschner correct that this falsified anything about the “greenhouse” effect?
-No.
Was that my point?
-Yes.
Oh how the rest of the world wished they had a debating opponent like Bryan..
scienceofdoom said
“Were Gerlich and Tscheuschner correct about the definition of infrared radation? -Yes.”
Then followed by
“Our duo are just demonstrating their ignorance of the absolute basics.”
Perhaps some others can see the connection between these two statements.
All SoDs other error discoveries are of the same standard.
G&T were making the point that the incoming Solar radiation contained more infra red than visable; hence many of the atmospheric effects ascribed to “the greenhouse effect” are in fact caused by direct solar radiation.
Byran:
Love your work!
Would you like to explain what exactly is falsified by the invisibility of 50%+ of solar radiation?
Let me help you out –
Discuss. True?
Well, accurate about green light vs yellow light I suppose.
Relevance to the inappropriately-named "greenhouse" effect?
I would applaud Gerlich and Tscheuschner if they renamed their paper:
"On highlighting some random but well-known definitions in climate science and thermodynamics and making them seem slightly more relevant than they actually are within the frame of physics“
SoD
“On highlighting some random but well-known definitions in climate science and thermodynamics and making them seem slightly more relevant than they actually are within the frame of physics“
Your flippant reply shows a careless attitude to the well known definitions.
Just for your information there are no discrepancies between the Physics definitions and the Thermodynamic definitions.
This is not surprising as thermodynamic theory is almost wholly the work of Physicists.
However there are major discrepancies between Climate Science and Physics/ Thermodynamics.
A recent contributor Robert Bauman urges all to examine carefully these definitions before moving on to more “advanced topics”.
A shaky grasp of the fundamentals leads to total confusion later on as the issues become more complex.
Bryan:
I agree that Physics and Thermodynamics have no discrepancies. My flippancy is aimed at the comedic paper by Gerlich and Tscheuschner.
And now, as previously requested:
scienceofdoom
What G&T falsified was the theory of Man Induced Global Warming through increased co2 emission.
What G&T referred to in your
“Solar Energy Breakdown and A Huge Success in Miseducation” paragraph
Was the tendency of many in the AGW camp to ignore the fact that solar radiation contained more IR than visible radiation.
This could lead to possible errors when looking at so called backradiation.
scienceofdoom
I have been informed by CRN administrator that the site has a virus.
My reply to your last post there has been waiting 3 days for moderation.
Since your post and my reply fit in with your thread here with your permission I will re post both here.
Bryan
It’s an empty claim. Until you demonstrate something of substance in a paper of significance.
In any standard introduction to climate science / atmospheric physics you will find the definition of “longwave” of greater than 4um and the definition of “shortwave” of less than 4um.
Longwave is terrestrial radiation.
Shortwave is solar radiation.
See The Sun and Max Planck Agree
In fact, this is the miseducation of Gerlich and Tscheuschner – claiming something of substance with no evidence.
I look forward to your demonstrating that significant mistakes have been made in measurements of atmospheric radiation through not understanding the difference between “longwave” and “infrared”.
Bryan:
So long as you meet the etiquette rules here you can go ahead.
ScienceofDoom:
June 23rd, 2010 at 10:45 pm
Bryan’s comments are always entertaining, and he should be complimented on this.
What the newcomer might miss – and I write this comment for them – is that any hint of a problem in conventional theories that will possibly cast doubt on the inappropriately-named “greenhouse” theory is enthusiastically grasped by Bryan without any critical thinking.
So, for example, again and again Bryan happily brings up the “problem” with the Stefan-Boltzmann law. For newcomers, this law is the equation that links radiated energy with the 4th power of temperature.
– E = emissivity x sigma x T^4
Well, all Gerlich and Tscheuschner did there was to point out that this calculation of energy radiated from a surface is the total “hemispherical emissive power” – all of the energy radiated from a surface in all directions.
This is usually in the first 10 pages of a chapter on basic radiation and well-known to everyone. (Not actually a problem). Stefan-Boltzmann’s law is a well-established law that is fundamental to thermodynamics. And yet Bryan has enthusiastically jumped on this “problem” because IT MIGHT cast doubt on stuff to do with the greenhouse effect.
Clearly Gerlich and Tscheuschner were having a laugh. At Bryan’s expense.
And Bryan has happily jumped on “possible problems” with Kirchhoff’s law. This law states that emissivity = absorptivity, which is a wavelength dependent property of every material. Another foundational thermodynamics property. The amusing side of this is that Bryan busily used this to claim that therefore downward surface radiation from the atmosphere is under question.
The problem for Bryan is that the theory predicts this downward radiation and the instruments that measure it match the theory. Yet for Bryan, the fact the G&T have mentioned a possible limiting condition in the formula means that it is in doubt. What about the *measurements*?
And in the final one of a series of posts – https://scienceofdoom.com/2010/05/28/the-first-law-of-thermodynamics-meets-the-imaginary-second-law/ – Bryan admitted “I don’t know” when shown a thought experiment of a -10′C body increasing the temperature of a 0′C body.
Having been pressed earlier, he agreed that if 10um radiation from a 10′C body was 80% absorbed by a 0′C body, then 10um radiation from a -10′C body would also be 80% absorbed.
Oh no. That means that radiation from a colder body can be absorbed by a hotter body. So either the first law of thermodynamics is in question, or Bryan’s fundamental premise is flawed.
Which is it to be? “I don’t know”
https://scienceofdoom.com/2010/05/28/the-first-law-of-thermodynamics-meets-the-imaginary-second-law/#comment-2598
Interested newcomers can check out the whole post and see how many times the specific question was asked before an answer was finally given. And also the difficulty in providing clarity on his own ideas:
https://scienceofdoom.com/2010/06/03/lunar-madness-and-physics-basics/#comment-2803
So for newcomers (who made it this far), if you want reasons to doubt the inappropriately-named “greenhouse” effect, follow Bryan!
If you want to find science answers, he may not be your ideal guide.
My reply toScienceofDoom:
You seem to be fascinated by the G&T paper unfortunately you do not seem to have read or understood the paper.
SOD says above ….
So, for example, again and again Bryan happily brings up the “problem” with the Stefan-Boltzmann law. For newcomers, this law is the equation that links radiated energy with the 4th power of temperature.
– E = emissivity x sigma x T^4
Well, all Gerlich and Tscheuschner did there was to point out that this calculation of energy radiated from a surface is the total “hemispherical emissive power” – all of the energy radiated from a surface in all directions.
Bryan responds
Here SOD implies that G&T are quite happy to use the Stefan-Boltzmann law.
Yet on page 12 we find
…that validity definitely does not cover the atmospheric problem…..
On page 21
….The T^4 law will no longer hold if one integrates only over a filtered spectrum…
…and so on.
SOD should stop making silly remarks that can so easily be exposed.
My advice to him is to read and consider carefully the G&T paper before making any further ill considered comments.
Will SOD thank me for my well meaning advice?
Wait and see!
Unfortunately, there is no precise expression in English for the useless, even counterproductive “well meaning advice” you offered him.
There is, however, a perfect expression for it in Russian, root for root, it would translate into English as “ursine assistance”; but how it comes to mean what it means is still too obscure for the English language reader. It is a reference to the Krylov Fable in which a bear moves in with a peasant, trying to help him. But every ‘help’ he offers is really hurt, until finally, the bear tries to swat a fly that landed on the peasant’s head — killing the peasant!
So yes, “ursine assistance” is the perfect characterization for your ‘advice’; except that in the case of the Krylov fable, we can count on those good intentions being genuine.
Bryan:
It’s very handy that G&T point out that the Stefan-Boltzmann equation is the integration of the Planck function over all wavelengths.
They do it in a way that impresses you – well, it’s great to learn something for the first time!
Every thermodynamics text book and every atmospheric physics text book will tell you that integrating the Planck function over all wavelengths gives you the relationship called the Stefan-Boltzmann relationship. And everyone who has studied the subject knows this.
Restating the definition in a slightly different way doesn’t expose a problem. It might impress people who don’t understand the subject..
Here’s an example to consider:
“However, it must be realized that kinetic energy is half the quadratic of the magnitude of the velocity vector times the mass. Failure to properly account for this already falsifies much of climate science.”
Do these words demonstrate a “problem” with kinetic energy? KE = m . v^2 / 2
Restating a formula in different words doesn’t mean that there is a problem with it.
Claiming that part of the scientific community doesn’t understand a basic proposition doesn’t mean it’s true. It’s a claim.
G&T are having a laugh!
And as I pointed out, the convective-radiative model doesn’t even use it. From the article above:
In fact climate science uses the formulae that G&T endorse to solve the radiative-convective model and reach all of the standard conclusions about the inappropriately-named “greenhouse” effect.
What G&T don’t do is explain what is wrong with using the formulae they endorse to solve the problem of radiative transfer in the atmosphere.
Or show what exact part of climate science “is falsified” by “incorrectly understanding” radiation 101.
It’s clear that Gerlich and Tscheuschner have never read one of the standard texts like “Atmospheric Radiation: Theoretical Basis” by R.M Goody. And it’s clear that they never read any of the standard papers like Climate Modeling through Radiative-Convective Models by Ramanathan and Coakley.
If they had they wouldn’t have embarrassed themselves so badly.
If they had read them and had found a flaw in them, they would have been sure to refer to them.
Well, there’s nothing to say that there aren’t flaws in these standard works about atmospheric radiation. I look forward to Gerlich and Tscheuschner’s paper where they actually cover real atmospheric physics.
Where they explain why the measured spectral results of downward longwave radiation at the surface and outgoing longwave radiation at the top of atmosphere closely match the solution to the theory as explained by RM Goody, by V Ramanathan and by many others.
And don’t forget to back up your claim
At least you have realized that the fact that 50%+ of solar radiation is infra-red doesn’t back up the G&T claim. We all agree about solar radiation and infra-red.
You just have to prove that it falsifies something in atmospheric physics.
“My dog is alive, therefore, he is a champion showdog.”
What do you mean? I’ve proved my dog is alive so obviously the statement is true..
I keep proving my dog is alive again and again and you still keep claiming that the statement is incorrect..
Actually, I don’t think he really needs to show it falsifies anything; all he really needs is to show that it renders one of the key arguments of atmospheric physics invalid.
Of course, he can’t do that either, since it isn’t even true. It is just another red herring.
scienceofdoom
What G&T falsified was the theory of Man Induced Global Warming through increased co2 emission.
What G&T referred to in your
“Solar Energy Breakdown and A Huge Success in Miseducation” paragraph
Was the tendency of many in the AGW camp to ignore the fact that solar radiation contained more IR than visible radiation.
This could lead to possible errors when looking at so called backradiation.
This remark was made by G&T in passing.
Its not a central part of their paper and could easily have been left out.
SOD you must be in absolute desperation if this is what you elevate to a misleading “error”.
G&T are quite correct in this rather trivial point.
scienceofdoom to clear up another of your misconceptions.
You might like to look up the experimental proof of the zeroth law of thermodynamics.
For years most people took this for granted but for SOD it might come as a revelation that the introduction to the vicinity of two objects at thermal equilibrium by a third object at the same temperature does not lead to a temperature gain/or loss of the original two.
G&T did no such thing. Their paper was full of too many errors to falsify anything, except for a “straw-man”.
Yes, I am afraid that is all they accomplished: a long and very poorly written straw-man argument.
Again: they ‘falsified’ nothing.
Bryan
Well, with this paper I’m really quite enjoying myself. Absolute desperation? We will let the readers judge.
I picked up this “irrelevant” point because many people on this blog and another very popular blog have often claimed that solar radiation cannot be differentiated from terrestrial radiation:
So it’s quite an important point. Perhaps G&T helped to originate the myth (the myth that terrestrial radiation is indistinguishable from solar radiation).
And so, before you move on too quickly, if G&T are “quite correct in this rather trivial point” – please produce the evidence.
It should be easy to do.
Or alternatively – you can concede their error as just a minor 1.5% of their paper and we can move on to another point.
SoD
Which page of G&T paper states this?
“because more than 50% of solar radiation is infrared.”
Bryan:
My comment is what others on this blog and another blog frequently say “solar radiation cannot be differentiated from terrestrial radiation ..because more than 50% of solar radiation is infrared..
This is what other people say (incorrectly)..
Do you see the connection?
Maybe you don’t..
The connection is – G&T have misled people, perhaps unintentionally, by appearing to support (or originating) the idea.
If you are confused, go back to the explanation about the dog.
“The dog is alive” – matches with “more than 50% of solar radiation is infrared”
And “therefore the dog is a champion showdog” – matches with “In most papers discussing the supposed greenhouse effect this important fact is completely ignored”
All you have to do now is demonstrate what is important about this fact for the inappropriately-named “greenhouse” effect.
SoD
My advice to you is keep it simple.
Do not introduce test “errors” into the discussion of climate science.
It must be apparent to all, that climate science has more than enough real errors than it can cope with.
Serendipity, it appears that zeroth law of thermodynamics is now the focus of recent comments in
The Earth’s Energy Budget – Part Four – Albedo
You are to be complemented on attracting such interesting contributions to your site.
At the moment I am reading Robert Baumans Thermodynamics text book (freely down-loadable from his site).
Its very good, careful explanation of fundamental terms.
His book uses statistical mechanics where appropriate.
Statistical mechanics is one area where I feel I need to brush up on.
Bryan:
I will await your conclusion to my earlier comment
That should keep it simple.
SoD
Look at some attempts to explain the so called “greenhouse effect” particularly those aimed at the public.
You will find plenty of examples like this;
Solar radiation from Sun reaching Earth surface.
Infra Red radiation leaving Earth surface.
This is presented in such a way as to perhaps suggest the two radiations are mutually exclusive.
I think G&T and any other responsible scientists are quite correct to clear up any misunderstanding this might cause.
Correction of above
zeroth law of thermodynamics is now the focus of recent comments in Venusian Mysteries – Part Two
Bryan:
G&T said:
Why are you bringing up the zeroth law of thermodynamics? We are discussing the G&T paper in this article. Why are you talking about “attempts to explain to the public”?
Papers.
“Most papers”!
So as you have been adamant that they are “quite correct”, please start identifying the papers.
“Most” is more than half. There most be so many. I know you want to tell everyone what they are..
If you like I could give you my list of influential papers and you could pick out the ones where this claim of G&T is true.
But I’m sure you have your own list.
scienceofdoom
You really are becoming preoccupied by trivia.
I looked up greenhouse effect on google giving Wikipedia, BBC and one other and got fed up.
All three gave the explanation that G&T got irritated by.
Try it yourself and if any other readers find this interesting, please enjoy.
…..”Why are you bringing up the zeroth law of thermodynamics?”…….
One of your other preoccupations is the radiation emitted by an object must change the temperature of a neighbouring object .
In your thread Radiation Basics and the Imaginary Second Law of Thermodynamics.
My post on the 15th May 8.32 was unanswered on this point.
It is an experimental arrangement to test the zeroth Law.
If you follow the logic and conclusions of this experiment you might find it easier to understand the G&T paper.
Bryan:
Becoming preoccupied by trivia?
Well I think it was you in numerous earlier comments claiming that G&T “were right” and I was wrong and wanting me to concede the point.
G&T said “In most papers discussing the supposed greenhouse eff ect this important fact is completely ignored.”
But it’s not true.
Your statement was “G&T are quite correct on this“.
So we can now move on as you have demonstrated to everyone that you have no knowledge of any papers which support your interpretation of G&T’s claim.
If you did you would be sure to produce them.
Perhaps G&T saw something on the BBC which irritated them as well, and got confused? It happens.
Scienceofdoom you said
G&T said “In most papers discussing the supposed greenhouse eff ect this important fact is completely ignored.”
I said, you really are becoming preoccupied by trivia.
I gave you examples readily available to readers where G&Ts irritation was occationed.
They are endless
G&T may produce a list of “serious papers” that also contain this misdirectiom of readers.
You may produce a list of papers that are quite innocent of this fault.
Where does that get us?
Certainly G&T are not responsible for the errors in Wikipedia, the BBC and so on.
They did not come up with the theory of CO2 being a threat to life on this planet.
I think the cental issue is to look at the effect of CO2 and come up with hard numbers about how its affects the rest of the planets temperatures.
[…] hilarious paper by Gerlich and Tscheuschner poured fuel on the confused world of the blogosphere by pointing out just a few pieces of the […]
A deliciously entertaining (and informative!) article and comment thread. Kudos all!
I suggest that the G&T paper should not be lightly dismissed:
> Its persistence indicates that there is much woolly thinking (or at least woolly description) around to be addressed.
> It has the first mention I have seen of Wood’s experiments of 1909, which put the topic of real greenhouses to bed.
> There is a general tendency to assume that inappropriate protest in some way invalidates the complaint; this I consider dangerous.
> Pondering what type of model might meet G&T’s criteria has led me to a starting-point which I haven’t seen elsewhere. I’ll share this when I’ve found where it fits (and if).
> While G&T, having inferred a Perpetual Motion Machine of the second kind in the atmospheric model immediately dismiss it, I suggest this be explored with dispatch; even if the chance of this existing is tiny, if proved the problem becomes the perfect solution – energy re-usable indefinitely without penalty, worldwide, out of thin air; Earth could provide no greater bounty.
I’m not a AGW sceptic, but think much of the debate is off the mark. I realised what I was reading on AGW did not employ all the vocabulary needed, and an improved search led me to SoD’s blogosphere.
This seems a fair test of descriptions. I suggest that SoD add a blog page for one-liners passing muster for relevance, correctness, and intelligibility; less as a summary than a guide to reliable thinking on the subject. I have a few tentative candidates for such:
> All EM emission implies an absorber.
[any useful discussion must include both]
> On the small scale, everything continuously loses energy by all available means.
[at equilibrium, only net heat flow is zero]
> All net heat transfer is directly proportional to the temperature difference between source and sink.
[for radiation, there is also a dependence on the average temperature^3; for convection, the (conducting) boundary layer limits, even with forced convection. These are approximations, but fair ones here]
> A steady-state model teaches nothing about its stability or its response to disturbance.
>TANSTAAFL
[there ain’t no such thing as a free lunch]
Maybe. If Wood’s results were correct. Abbot pointed out in 1909 five months later that the temperature attained by Wood was quite low, which cast doubt on the validity of Wood’s data.
Vaughan Pratt has attempted to replicate Wood. He found that a box with an LW IR transparent window had a lower temperature than a similar box with an LW IR opaque material like window glass or acrylic plastic.
http://boole.stanford.edu/WoodExpt/
Nasif Nahle has also conducted experiments similar to Wood. He claims that his work validates Wood, but his IR transparent covered box was insulated with fiberglass while the boxes covered with glass and acrylic plastic were not (Picture 06, page 6). Later (pp 22-24) he shows that the fiberglass insulated box is 10 C warmer than a similar box when both are covered with LW IR transparent polyethylene film. Therefore, his experimental results are similar to Vaughan Pratt’s results, i.e. a box with an LW IR transparent window has a lower temperature than a box with an LW IR opaque material, not the same temperature.
Click to access Experiment_on_Greenhouse_Effect.pdf
I have also performed some experiments with cardboard boxes painted black on the inside with glass, acrylic and polyethylene film windows. In all cases, the box with the IR transparent polyethylene film window has a lower temperature than boxes with IR opaque windows. The temperature and the temperature difference increases as the insulation of the box walls increases.
(Work in progress)
The conclusion is that Wood was wrong (although why he was wrong is an interesting question) and the greenhouse effect is not a misnomer. A planetary atmosphere works exactly the same as an horticultural greenhouse. The difference is that a planetary atmosphere is effectively perfectly insulated while an horticultural greenhouse isn’t.
The obvious counter example to Wood is in almost every home. It’s an oven with a glass window. Imagine how much power it would require to heat that oven if that window were LW IR transparent.
DeWitt – the glass oven door is also providing a mass transfer barrier. On the ovens I have seen and used the thermal barrier is really only effective when glass is used in a double glazed panel.
curious,
Of course it does. In that, it is no different than a door with no window. But IR opaque glass provides a radiative barrier as well as a convective/conductive barrier. One could potentially construct a window using two layers of IR transparent material that would provide the same physical barrier. But there would be a large loss of energy by radiation.
Example; The door on my oven is about 18″x12″ or 0.45m x 0.3m = 0.135 m2. At an oven temperature of 450 F = 505.37 K, the heat loss by radiation, assuming a room temperature of 21 C = 294.15 K would be σ * (505.37^4-294.15^4)*0.135 = 442 W. Your average oven is on a 220V/20A circuit and that includes the four or more surface heating elements. 442 W is likely more power than is used to maintain the oven temperature at 450 F in the absence of significant radiative heat loss.
DeWitt Payne
I thought you might be interested in a new peer reviewed paper by Gerhard Kramm and Ralph Dlugi.
They are big fans of Gerlich and Tscheuschner .
They reaffirm their conclusion that the greenhouse theory is a set of merit-less conjectures with no physical support.
Of particular interest is ;
The energy reservoir diagram Fig 11
The irradiance overlap area Fig 5
On a more humorous note they find further errors in the Halpern et al comment paper
See page 1316
Wrong formula
Wrong units
Which of course leads to silly numbers.
I make it 0.71W/m2K for entropy flux.
Perhaps SoD should re-title this thread as;
On the education of the Uninformed by Gerlich and Tscheuschner .
http://www.scirp.org/journal/PaperInformation.aspx?paperID=9233
How is this post not a violation of the posting guidelines? It is Bryan’s post that is completely without merit. There is no new evidence to support Gerlich and Tscheuschner’s claims, only baseless counterclaims whose sole ‘merit’ is that they suppor the position Bryain already insists on believing.
It reminds me of this crank on math.sci years ago who insisted he had disproved Einstein’s Theory of Special Relativity, and called anyone who disagreed with him an “Einstein dingleberry”. He too would come up with reams and reams of completely contrived evidence to support his POV.
Matt,
The post is roughly on topic. It isn’t mindless repetition. It isn’t an essay. The posting guidelines don’t prevent people posting stuff that is wrong.
Which bit were you thinking of?
Of course, it would be wonderful to find out which of the specific criticisms in this article are now proven incorrect by this new paper – but that would be setting lofty standards indeed.
Actually, I have to disagree. On a slightly more abstract level, Bryan’s post is “mindless repetition”, and it is the kind of repetition I have learned to expect from him in many forums, not just this one.
Now true, it is not mindless repetition of the exact same words, or the exact same claim. But it is mindless repetition in the following sense: whenever sound evidence is presented that AGW is real and the ‘skeptical’ argument wrong, Bryan comes up with ‘facts’ that are either irrelevant, out of context, or simply wrong. He then cobbles up the appearance of a refutation of AGW and support for the skeptics, but it never is either one.
The “greenhouse theory” as he calls it, is NOT “set of merit-less conjectures with no physical support.” Bryan has provided only the appearance of support for his rejection of well-established science.
Bryan,
Do the authors of this new paper address the question I don’t think you ever answered – what happens to the energy radiated by the atmosphere when it “reaches” the ground? If they do, it might be interesting to read the paper.
What happens when a single photon from a colder source reaches a hotter surface?
I don’t think anyone has proof of what happens next for a single photon.
If we believe in the quantum theory it is highly dependent on its photons wavelength and the physical situation of the absorbing medium.
There is no reason to say that it cannot be absorbed if the conditions are correct.
So for a large number of photons from the atmosphere (know as downwelling long wave radiation) landing on ,say water, most will be absorbed.
This has the effect of reducing the heat loss from the warmer water.
This radiation is often called backradiation.
We also have backconduction and backconvection which don’t seem to get the attention they deserve.
All three of these will produce an insulating effect by slowing down heat loss from the water.
The relative importance of each of these processes has to be quantified.
Generally they are grossed up and represented by bulk quantities such as
the heat capacity of air and water respectively.
Your question makes no sense, Brian. How can you combine in the same sentence “single photon” and both “hotter” and “colder”? You are mixing models incorrectly, like a freshman who hasn’t figured out statistical mechanics yet.
“Single photons” are a mathematical abstraction, appropriate to use when considering a single interaction between that photon and a field or particle. But “hotter” and “colder” are macroscopic properties of a large ensemble of particles or field oscillators. Mixing the two is just incorrect.
As for your objection about ‘backconduction’ and ‘backconvection’, that is so completely off-base, it sounds like you aren’t even trying. Despite your assertion, the reason they get so little attention is because we already know they are signficantly smaller than radiative heat transfer. The thermal contact between the upper atmosphere, earth surface and sun IS radiative, not convective or conductive.
Nevertheless, much work HAS gone into expanding the models to deal with convection, too. See http://en.wikipedia.org/wiki/Climate_model for just a few examples. But the basic result is the same: AGW really is man-made, and it is very serious.
Matt J says
“Single photons” are a mathematical abstraction,
However there is a number of substantial papers on just such an entity.
physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.243602
Matt goes on to say
“‘backconvection’, that is so completely off-base, it sounds like you aren’t even trying. Despite your assertion, the reason they get so little attention is because we already know they are significantly smaller than radiative heat transfer.”
Well here once again is the adiabatic atmosphere explanation.
Backconvection is the return leg of compression that raises the temperature of the air parcel to close on the rising leg of expansion and cooling.
1. Earth surface heated by Sun.
2. Air in contact with Earth surface will leave with the characteristic temperature of the surface.
3. The concept of an air parcel is almost universally adopted to describe the temperature profile of the troposphere.
4. Air parcel considered to be in hydrostatic equilibrium is used to analyse thermodynamic behaviour of troposphere.
5. Air parcel in hydrostatic equilibrium means it is either stationary or moving with constant velocity i.e. no unbalanced force acts on body
6. The dry adiabatic lapse rate(DALR) can be derived for dry air by combining the laws of thermodynamics with the hydrostatic condition.
dP = – density x gravitational field strength x dz
DALR = – g/Cp = – 9.8 K/km
Derived from stationary condition showing DALR does not depend on convection being present.
7. For ascending parcel
The air parcel does work Pdv in expanding the air parcel.
This work is supplied by the internal energy of the air parcel causing the temperature inside the parcel to drop.
This loss in internal energy is stored in the atmosphere(surroundings).
There is a slight loss of energy by radiation which becomes more significant at higher altitudes
8. For descending parcel (or back convection)
The air parcel is slightly denser than surrounding atmosphere and so descends.
The surrounding atmosphere does work Pdv compressing the air parcel.
This results in an increase in the temperature of the parcel.
The internal energy of the air parcel rises causing the temperature inside the parcel is increasing.
This gain in internal energy is matched by the loss of atmosphere(surroundings) energy.
With water vapour present in air lapse rate decreases and is called the environmental lapse rate and an average figure of around -6.5 K/km is obtained
The average effective radiation altitude(AERA) is taken to be about 5 Kilometres where the temperature is 255K.
By working back from AERA to the surface the air temperature increases to give the average surface temperature of 278K or 15C.
All this achieved without any so called Greenhouse Effect.
Other points to notice is that by adiabatic condition implies that no heat enters or leaves the air parcel.
Further since no heat is exchanged there is no entropy increase for the idealised convection cycle.
This means that revisable conditions are observed for the whole cycle.
The only significnt heat loss occurs by;
1. the Earth surface to atmospheric gases at surface boundary
2. Radiative loss to space at TOA.
True to form, Bryan, you have offered a ‘rebuttal’ that has only the superficial appearance of scientific reasoning, but none of the substance.
How, for example, did you dream to refute my point about the isolated photon being a mathematical abstraction by providing ONE link to a paper, claiming the existence of many papers, “here is a number of substantial papers on just such an entity. ”
If you actually READ the paper, you would see that it too treats the photon as a mathematical abstraction. How do you THINK they measure its velocity? By interaction with the field due to an ensemble of particles, at which point it is no longer an isolated photon.
So now that I see how you failed to refute my point because you didn’t even understand it, I am not going to even bother to plough through your out of context quotation of miscellaneous aspects of the “adiabatic atmosphere” theory.
In fact, I don’t have to go through the details to notice some serious flaws. Did it ever occur to you that the assumptions of this theory are only an approximation? Did it ever occur to you that there is no guarantee that those assumptions are or need to be with those of AGW? Science often uses the results of two different models side by side even when their respective assumptions are contradictory. There is nothing unscientific about that; the Manhattan Project would have failed if there were.
And where did you get this idea that “no heat transfer” implies “no entropy increase”? Do you really find the concept of global integrating factors that challenging? It is easy to find a path in state space for which DeltaQ is zero, but DeltaS is not.
With bloopers like this, you have certainly failed to substantiate your claim that “revisable conditions are observed for the whole cycle.”
Matt J
You are beginning to sound a bit like Claes Johnson.
He too thinks there is so such a thing as a single photon.
He thinks that they were a mathematical abstraction invented to produce a quick fix for the ultraviolet catastrophe and the photoelectric effect.
I on the other hand will stick with orthodox quantum physics which believes in such entities.
I gave you a single paper.
Google single photon and you will find more papers than you can read in a month.
Back to my original point which was;
“I don’t think anyone has proof of what happens next for a single photon.”
Now what reasonable person could object to that statement?
Claes is right. The “orthodox quantum physics” you claim to stick to you do not even understand. For if you did understand it, you would realize that it too admits the single photon only as a mathematical abstraction, requiring “collapsing wavefunctions” whenever you actually measure any property of that “single photon”.
But you are still missing my main point: you are very off-base mixing talking about single photons, which by definition are microscopic, with thermodynamic quantities, which again by definition, are macroscopic.
Matt J. says
“Claes is right.”
I can understand why you think photons and in particular single photons are nonsense.
I on the other hand think EM radiation comes in well defined (by wavelength) packets with particle as well as wave properties.
However even Claes could not find fault with my opening statement .
“I don’t think anyone has proof of what happens next for a single photon.”
Oh, so now, Brian, you are putting words in Claes’ mouth? How do YOU know he doesn’t find fault with your amateurish blooper? For that is what it is. You CANNOT make a meaningful statement about thermodynamic quantities based on a single particle. Even college freshmen should know this. So your objection that no one can say what the “single photon” does is completely meaningless and irrelevant. No thermodynamic quantity changes value due to the interaction with a single photon.
Matt J.
I wrote
“I don’t think anyone has proof of what happens next for a single photon.”
You have tied yourself in knots trying to find fault with a statement that is hyper uncontentious.
You strike me as a candidate for the Monty Python argument room.
You don’t really need me.
You are quite capable of having an argument with yourself.
Matt J. says
“And where did you get this idea that “no heat transfer” implies “no entropy increase”? Do you really find the concept of global integrating factors that challenging? It is easy to find a path in state space for which DeltaQ is zero, but DeltaS is not.”
You seem to have problems reading what is actually written.
I said there was no entropy change in the ADIABATIC PHASES when combined.
You are in need of revising the Carnot Cycle and an eye test should not be ruled out
No, Bryan, then as now, the fault is in what you wrote. This time, for example, you surely could not have meant ‘revising’ the Carnot cycle, but ‘reviewing’ it. A ‘revised’ Carnot cycle would havce been even less relevant than what you wrote;)
But that still does not help you, since you really did fail to condition your statement on the condition that it be adiabatic.
If such sloppy writing is the best you can do, no wonder you turn so quickly to ad hominem attacks, as you did so often in other forums as well.
Bryan,
Natural Science isn’t exactly a top rank journal. It only started publishing in 2009.
The only thing I find fascinating about G&T is that people take it seriously.
If you submit a publication to enough journals, you’ll eventually find one with standards low enough to accept pretty much anything. That’s how Miskolczi and G&T were published. Nasif Nahle claims his article about replicating Wood’s experiment was peer reviewed.
Kramm and Dlugi are no more credible than G&T. Let’s just look at the first paragraph of the Introduction:
Wrong. I don’t even think that’s a correct paraphrase of what G&T actually claimed. But even so, no one, not even Nasif Nahle, has been able to reproduce Wood’s result. The physical laws are, in fact, exactly the same.
Wrong. G&T wave their hands a lot, but in the end they can only assert that conclusion. They never prove it.
Wrong again. It isn’t meaningless and it is calculated correctly for the assumption of an isothermal sphere. It is easy to show that a sphere only has to be close to isothermal for the difference in average temperature to be minimal. You can do it with a spreadsheet.
Wrong again.
Moving the goalposts. No one claims that exact radiative balance must exist at all times. The claim is that surface temperature and heat content will adjust to minimize radiative imbalance, which is exactly what must happen when there is an imbalance according to the conservation of energy.
They aren’t set to zero, they are ignored because they’re vanishingly small effects. It’s like claiming that heat from the core is the reason why the Earth’s surface is warm. Yes there is heat from the core, but it’s a tiny fraction of the energy absorbed from solar radiation. Thermal conductivity in air is ignored in Physical Meteorology because it’s very small compared to convection and radiation. Only a small fraction of incoming solar radiation is converted to air and water circulation. That energy is rapidly dissipated. That’s why it’s not calculated separately. G&T completely fail to support their conclusion that the atmospheric greenhouse conjecture is falsified.
Since Kramm and Dlugi have demonstrated their incompetence by accepting G&T as correct, there’s not much point in going further.
DeWitt Payne
All you have done is to issue a series of unproven assertions.
I could contest all of them with logic and evidence.
However SoD has opened a new post featuring Kramm and Dlugi and its best to reply there.
We now have two peer reviewed papers coming to much the same conclusions.
That the greenhouse theory is a set of merit-less conjectures with no physical support.
As the climategate e-mails show there is a background of suppression of reports that are considered to challenge the consensus IPCC view.
So having two peer reviewed papers is no mean feat.
How is your experiment to refute Woods coming along?
All we have is a set of preliminary reports.
You will need to do better than that before you can be taken seriously.
Yes, two “peer-reviewed” papers, but all that REALLY proves is that the peer review process is flawed, and easily manipulated when politics and money are involved. But we should have figured this out from the tobacco examples five decades ago.
As SOD has already shown in numerous posts, the first of the two papers should never have passed peer review, it is so FULL of errors. If the latter agrees with it, chances are it too is filled with errors, probably even the same errors.
As for your much-vaunted ‘logic’, you are long on words and short on substance: where is the ‘logic’ in you sophomoric question about what happens with a “single photon”? There isn’t any.
Matt J says
where is the ‘logic’ in you sophomoric question about what happens with a “single photon”? There isn’t any.
My statement again
“I don’t think anyone has proof of what happens next for a single photon.”
Possibility 1 – Someone has proof and I’m surprised
Possibility 2 – Photons don’t exist – hence no proof
Possibily 3- Heisenberg Uncertainty consideration hence no proof
You perhaps will add your own but you will find the statement cannot be faulisified
Bryan,
You still don’t get it. G&T is simply a collection of unproved assertions including the ultimate assertion where they claim falsification. They prove nothing that isn’t already known like Hölder’s Inequality and how it relates to global average temperature. A lot of the rest is nitpicking about semantics and word choice as Kramm does in the Dlugi and Kramm thread.
DeWitt Payne
You cannot claims results on the basis of leaks about your new experiment.
Publish full results like Vaughan Pratt and Nasif Nahle
By the way Vaughan Pratt does not publicly defend his experiment.
He is now engaged in an improved version.
Matt J. says..
…..”It is Bryan’s post that is completely without merit. There is no new evidence to support Gerlich and Tscheuschner’s claims.”…..
Quite the contrary it is the theme of this thread.
My post was specifically addressed to DeWitt Payne who is fascinated by G&T.
Its a peer reviewed post than leans heavily on their excellent work.
Perhaps others like Matt J would like to emulate an ostrich and find some sand to stick their head in.
Bryan,
Following on from my earlier question (December 31, 2011 at 9:29 pm)..
1. Do you think this is a good paper?
2. Do you think it has any mistakes?
3. And while they claim to be big fans of Gerlich and Tscheuschner, do you think Kramm & Dlugi actually agree with their (G&T’s) main tenet?
scienceofdoom says Bryan,
1. Do you think this is a good paper?
Reply…….Yes
2. Do you think it has any mistakes?
Reply…….Not any I have noticed on first reading
3. And while they claim to be big fans of Gerlich and Tscheuschner, do you think Kramm & Dlugi actually agree with their (G&T’s) main tenet?
Reply…….K&D and G&T both share the same main tenet which is the radiative effects in the Earth/atmosphere system known as the greenhouse effect is based on unfounded conjectures.
In particular they disagree that the effect explains the 33K difference between TOA and the Earth surface temperatue
Bryan,
What about eqn 2.17 (p. 983), do you think it is correct?
scienceofdoom
One thing about the equation2.17 that I would seek clarification on is the definition of Rs.
Does he mean the total incoming solar radiation?
To mention diffusive radiation here creates uncertainty coupled with the fact that Rs is then due to be corrected for reflection by albedo of around 0.3.
Perhaps you were thinking of some other problem with the equation?
What do you make of the term in there: ε (θ,φ) RL↓(θ,φ)
I read it as saying that the energy balance at the surface includes a term which is the absorptivity of the surface x the incident atmospheric radiation.
There are no other caveats or modifiers.
The absorbed solar radiation is treated exactly the same as the absorbed atmospheric radiation. Both contribute equally (according to their respective values) to the surface temperature. Yet one is from a higher temperature source and the other is from a lower temperature source.
(Of course, this equation would be integrated over all angles to get the total hemispherical flux).
Correction – the comment in brackets is not correct and couldn’t be correct. The equation is written as a function of location..
scienceofdoom says
“What do you make of the term in there: ε (θ,φ) RL↓(θ,φ)”
Im quite happy about that term as it seems to be the down welling IR (sometimes called backradiation).
The ε (θ,φ) factor for IR radiation by IPCC science should be around 1
Whereas the ε (θ,φ) factor for short wave solar is around 0.85
Excellent news, but I’m sure there’s a sting in the tail somewhere.
You say “The ε (θ,φ) factor for IR radiation by IPCC science should be around 1. Whereas the ε (θ,φ) factor for short wave solar is around 0.85”
Does this mean that you have a different value for ε (θ,φ) but agree with the short wave value (which could also have appended “..by IPCC science“) ?
scienceofdoom
“Does this mean that you have a different value for ε (θ,φ)”…..for short and long wave EM radiation.
Yes I think this is one aspect of climate science we can all agree with.
The absorptivity/emissivity of the Earth surface is wavelength dependent.
I am pleased`to see this thread revived, and the old familiar arguments repeated. Warming back-radiation has returned, with SOD’s (sylas’s?) mantra asking where the downward energy goes? It nets against the outgoing radiation, sylas, to produce the heat transfer.
Two bodies at the same temperature will radiate energy to each other, but their heat transfer (net energy) will be zero.
The cooling effects for the earth, earth to atmosphere, are evaporatioin (latent heat), convection, net radaition, and conduction. They are`all cooling effects. The only warming is from the sun.
So why is the surface warmer than the atmosphere? Because of the lapse rate, which numerous contributors have correctly defined as a function of specific heat and gravity, not radiation.
Providing only that all the heat transferred from the surface can be (and is) absorbed, radiation to space will be from the atmosphere, not the surface.
Here is one of the principal pundits from RC, Ray Pierrhumbert:
“In a nutshell, then, here is how the greenhouse effect works: From the requirement of energy balance, the absorbed solar radiation determines the effective blackbody radiating temperature Trad. This is not the surface temperature; it is instead the temperature encountered at some pressure level in the atmosphere prad, which characterizes the infrared opacity of the atmosphere, specifically the typical altitude from which infrared photons escape to space. The pressure prad is determined by the greenhouse gas concentration of the atmosphere. The surface temperature is determined by starting at the fixed temperature Trad and extrapolating from prad to the surface pressure ps using the atmosphere’s lapse rate, which is approximately governed by the appropriate adiabat. Since temperature decreases with altitude over much of the depth of a typical atmosphere, the surface temperature so obtained is typically greater than Trad, as illustrated in Figure 3.6.
Increasing the concentration of a greenhouse gas decreases prad, and therefore increases the surface temperature because temperature is extrapolated from Trad over a greater pressure range. It is very important to recognize that greenhouse warming relies on the decrease of atmospheric temperature with height, which is generally due to the adiabatic profile established by convection”
If we could all accept this, we could move on to discuss the crucial issue: by how much will the average emission point be raised if the CO2 concentration doubles?
In effect, the world is conducting a gigantic experiment to find`out. The crucial evidence is the mid-troposphere temperature at about 6 kilometers elevation. It is available from two independent sources, satellites and radio-sondes.
The CO2 concentration increased`very slowly from about 290 ppm in 1880 to 310 ppm in 1960. Thereafter the pace quickened, to close to 400 ppm today. UAH, RSS, and HADAT temperatures are`available from Global Warming at a Glance.
[…] cannot be true because it would somehow violate the second law of thermodynamics. If there was a scientific idea in Gerlich & Tscheuschner, this was probably the main one. Or at least the most […]
“…this was probably the main one” — and as SOD has painstakingly explained, that ‘main one’ is simply wrong. Wrong on many levels, too. There is no contradiction of the 2nd Law of Thermo in the explanation of the “greenhouse effect”. Only in over-simplified versions of it, which versions now appear primarily in “straw-man” arguments coming from the —–ists. [Moderator’s note – please read the Etiquette]
Fred may rejoice at the revival of this thread; I must say I found it amazingly tedious–rather as if the “Black Knight” sketch had gone on for the entire length of “Monty Python And The Holy Grail.”
[…] No surprise to people familiar with the basics of radiative heat transfer. However, Kramm & Dlugi are apparently “in support of” Gerlich & Tscheuschner, who famously proposed that radiation from the atmosphere affecting the temperature of the ground was a violation of the second law of thermodynamics. A perpetual motion machine or something. (Or they were having a big laugh). For more on the exciting adventures of Gerlich & Tscheuschner, read On the Miseducation of the Uninformed.. […]
[…] […]
[…] (Examples: https://scienceofdoom.com/2010/03/14/on-having-a-laugh-by-gerlich-and-tscheuschner-2009/, https://scienceofdoom.com/2010/04/05/on-the-miseducation-of-the-uninformed-by-gerlich-and-scheuschner…, http://atmoz.org/blog/2007/07/10/falsification-of-the-atmospheric-co2-greenhouse-effects/) That […]
Pսis-jе recopier plusieurs liǥnes sur un blogg personnel ?
Thank you for your work, saves a lot of my time dealing with belivers!
A comparatively speedy collapse could even be preferable to continued financial mishandling, followed by an eventual, larger,
collapse.
I was hopeful I’d get a scientific rebuttal of Gerlich and Tscheuschner in your two critiques of their papers. Instead, I see you know less climate science than they did, which is a monumental achievement considering they readily admit they are not climate scientists (it says so even in the title of the paper). Worse yet, you seem to be unable to follow thermodynamics in textbooks or even the simplest of atmospheric physics from any source. Do you really believe any text book on thermodynamics provides an example of a cool body transferring heat energy to a warmer body? If so, then why hasn’t anyone invented a machine which remains in perpetual motion? Why don’t we simply build vacuums around homes so winter weather can heat the interiors? C’mon, you can’t seriously think you’ve understood any of G&T with such clearly deficient scientific knowledge?
olsonjs444,
“Do you really believe any text book on thermodynamics provides an example of a cool body transferring heat energy to a warmer body?”
Not that old canard again. You clearly don’t know anything about the mechanism of the greenhouse effect if you think doing that is necessary. The term ‘heat’ has different meanings in thermodynamics depending on exactly what is happening. In your example, heat means the NET energy transfer, which is always from hot to cold. But that does not mean there is zero energy transfer from the colder body to the warmer. It means that more energy is transferred from the warmer body to the colder body that the other way around. The difference is the heat transfer.
Individual emitted photons have no information about the temperature of the surface from which they were emitted. The absorption of a photon depends only on the absorptivity, reflectivity and transparency of the surface that it interacts with, not the temperature.
G.&T.’s paper is best described by the old saw: what’s correct isn’t new and what’s new isn’t correct. Their arguments against the greenhouse effect are all straw men based on verbal simplifications that they carefully cherry pick from public sources, not peer reviewed scientific papers.
[…] [8] On the Miseducation of the Uninformed by Gerlich and Tscheuschner (2009) […]