Guest post by Ira Glickstein
The Atmospheric “greenhouse effect” has been analogized to a blanket that insulates the Sun-warmed Earth and slows the rate of heat transmission, thus increasing mean temperatures above what they would be absent “greenhouse gases” (GHGs). Perhaps a better analogy would be an electric blanket that, in addition to its insulating properties, also emits thermal radiation both down and up. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because GHGs absorb outgoing radiative energy and re-emit some of it back towards Earth.
Many thanks to Dave Springer and Jim Folkerts who, in comments to my previous posting Atmospheric Windows, provided links to emission graphs and a textbook “A First Course in Atmospheric Radiation” by Grant Petty, Sundog Publishing Company.
Description of graphic (from bottom to top):
Earth Surface: Warmed by shortwave (~1/2μ) radiation from the Sun, the surface emits upward radiation in the ~7μ, ~10μ, and ~15μ regions of the longwave band. This radiation approximates a smooth “blackbody” curve that peaks at the wavelength corresponding to the surface temperature.
Bottom of the Atmosphere: On its way out to Space, the radiation encounters the Atmosphere, in particular the GHGs, which absorb and re-emit radiation in the ~7μ and ~15μ regions in all directions. Most of the ~10μ radiation is allowed to pass through.
The lower violet/purple curve (adapted from figure 8.1 in Petty and based on measurements from the Tropical Pacific looking UP) indicates how the bottom of the Atmosphere re-emits selected portions back down towards the surface of the Earth. The dashed line represents a “blackbody” curve characteristic of 300ºK (equivalent to 27ºC or 80ºF). Note how the ~7μ and ~15μ regions approximate that curve, while much of the ~10μ region is not re-emitted downward.
“Greenhouse Gases”: The reason for the shape of the downwelling radiation curve is clear when we look at the absorption spectra for the most important GHGs: H2O, H2O, H2O, … H2O, and CO2. (I’ve included multiple H2O’s because water vapor, particularly in the tropical latitudes, is many times more prevalent than carbon dioxide.)
Note that H2O absorbs at up to 100% in the ~7μ region. H2O also absorbs strongly in the ~15μ region, particularly above 20μ, where it reaches 100%. CO2 absorbs at up to 100% in the ~15μ region.
Neither H2O nor CO2 absorb strongly in the ~10μ region.
Since gases tend to re-emit most strongly at the same wavelength region where they absorb, the ~7μ and ~15μ are well-represented, while the ~10μ region is weaker.
Top of the Atmosphere: The upper violet/purple curve (adapted from figure 6.6 in Petty and based on satellite measurements from the Tropical Pacific looking DOWN) indicates how the top of the Atmosphere passes certain portions of radiation from the surface of the Earth out to Space and re-emits selected portions up towards Space. The dashed line represents a “blackbody” curve characteristic of 300ºK. Note that much of the ~10μ region approximates a 295ºK curve while the ~7μ region approximates a cooler 260ºK curve. The ~15μ region is more complicated. Part of it, from about 17μ and up approximates a 260ºK or 270ºK curve, but the region from about 14μ to 17μ has had quite a big bite taken out of it. Note how this bite corresponds roughly with the CO2 absorption spectrum.
What Does This All Mean in Plain Language?
Well, if a piece of blueberry pie has gone missing, and little Johnny has blueberry juice dripping from his mouth and chin, and that is pretty good circumstantial evidence of who took it.
Clearly, the GHGs in the Atmosphere are responsible. H2O has taken its toll in the ~7μ and ~15μ regions, while CO2 has taken its bite in its special part of the ~15μ region. Radiation in the ~10μ region has taken a pretty-much free pass through the Atmosphere.
The top of the Atmosphere curve is mostly due to the lapse rate, where higher levels of the Atmosphere tend to be cooler. The ~10μ region is warmer because it is a view of the surface radiation of the Earth through an almost transparent window. The ~7μ and 15μ regions are cooler because they are radiated from closer to the top of the Atmosphere. The CO2 bite portion of the curve is still cooler because CO2 tends to be better represented at higher altitudes than H2O which is more prevalent towards the bottom.
That is a good explanation, as far as it goes. However, it seems there is something else going on. The ~7μ and ~15μ radiation emitted from the bottom of the Atmosphere is absorbed by the Earth, further warming it, and the Earth, approximating a “blackbody”, re-emits them at a variety of wavelengths, including ~10μ. This additional ~10μ radiation gets a nearly free pass through the Atmosphere and heads out towards Space, which explains why it is better represented in the top of the Atmosphere curve. In addition, some of the radiation due to collisions of energized H2O and CO2 molecules with each other and the N2 (nitrogen), O2 (oxygen) and trace gases, may produce radiation in the ~10μ region which similarly makes its way out to Space without being re-absorbed.
There is less ~15μ radiation emitted from the top of the Atmosphere than entered it from the bottom because some of the ~15μ radiation is transformed into ~10μ radiation during the process of absorption and re-emission by GHGs in the atmosphere and longwave radiation absorbed and re-emitted by the surface of the Earth.
Source Material
My graphic is adapted from two curves from Petty. For clearer presentation, I smoothed them and flipped them horizontally, so wavelength would increase from left to right, as in the diagrams in my previous topics in this series. (Physical Analogy and Atmospheric Windows.)
Here they are in their original form, where the inverse of wavelength (called “wavenumber”) increases from left to right.
Source for the upper section of my graphic.
Top of the Atmosphere from Satellite Over Tropical Pacific.
[Caption from Petty: Fig. 6.6: Example of an actual infrared emission spectrum observed by the Nimbus 4 satellite over a point in the tropical Pacific Ocean. Dashed curves represent blackbody radiances at the indicated temperatures in Kelvin. (IRIS data courtesy of the Goddard EOS Distributed Active Archive Center (DAAC) and instrument team leader Dr. Rudolf A. Hanel.)]
Source for the lower section of my graphic.
Bottom of the Atmosphere from Surface of Tropical Pacific (and, lower curve, from Alaska).
[Caption from Petty: Fig. 8.1 Two examples of measured atmospheric emission spectra as seen from ground level looking up. Planck function curves corresponding to the approximate surface temperature in each case are superimposed (dashed lines). (Data courtesy of Robert Knutson, Space Science and Engineering Center, University of Wisconsin-Madison.)]
The figures originally cited by Dave Springer and Tim Folkerts are based on measurements taken in the Arctic, where there is far less water vapor in the Atmosphere.
[Fig. 8.2 from Petty] (a) Top of the Atmosphere from 20km and (b) Bottom of the Atmosphere from surface in the Arctic. Note that this is similar to the Tropical Pacific, at temperatures that are about 30ºK to 40ºK cooler. The CO2 bite is more well-defined. Also, the bite in the 9.5μ to 10μ area is more apparent. That bite is due to O2 and O3 absorption spectra.
Concluding Comments
This and my previous two postings in this series Physical Analogy and Atmospheric Windows address ONLY the radiative exchange of energy. Other aspects that control the temperature range at the surface of the Earth are at least as important and they include convection (winds, storms, etc.) and precipitation (clouds, rain, snow, etc.) that transfer a great deal of energy from the surface to the higher levels of the Atmosphere.
For those who may have missed my previous posting, here is my Sunlight Energy In = Thermal Energy Out animated graphic that depicts the Atmospheric “greenhouse effect” process in a simlified form.
I plan to do a subsequent posting that looks into the violet and blue boxes in the above graphic and provides insight into the process the photons and molecules go through.
I am sure WUWT readers will find issues with my Emissions Spectra description and graphics. I encourage each of you to make comments, all of which I will read, and some to which I will respond, most likely learning a great deal from you in the process. However, please consider that the main point of this posting, like the previous ones in this series, is to give insight to those WUWT readers, who, like Einstein (and me :^) need a graphic visual before they understand and really accept any mathematical abstraction.
I (Ira) do not agree with the line to which I have added Emphasis, but I think it is great that this cross-discussion is going strong 11 days after my original post. THANKS to ALL. Way to go!
Bryan, please have another look at the CO2 spectrum in my first graphic above. Notice how it peaks at 100% between ~15μ to ~18μ. H2O does not get up to 100% until ~18μ and it doesn’t stay there until ~20μ and above.
Now, have a look at the bite taken out of the radiation going out to Space (either in my first graphic or in Petty 6.6 or 8.2, also reproduced above).
You don’t have to be a dentist to see that the teeth marks match the bite. Therefore, as I wrote:
Bryan,
The challenge instead seems to be to make it so clear that you cannot invent another attack. At least 3 people (including now the original author) in multiple posts have explained that the “bite shape” is all wrong to possibly be water.
You ignored this and tried looking at the “bite depth” claiming that the greater concentrations of H2O would make it much more important than the CO2. The problem here is that the absorption is ALREADY weighted according to atmospheric concentrations. The common graph found all around the internet is “Absorption spectra for major natural greenhouse gases in the earth’s atmosphere. (After J. N. Howard, 1959: Proc. I.R.E. 47, 1459; and R. M. Goody and G.D. Robinson, 1951: Quart. H. Roy. Meteorol. Soc. 77, (153)” for example at http://www.iitap.iastate.edu/gccourse/forcing/images/image7.gif
This shows the absorption seen in the atmosphere due to typical concentrations. There is no need to re-adjust the strengths of the absorption due to concentrations. Look at the “total” absorption and you will clearly that it is the combination of the previous lines, not weighted 30 times more for water.
P.S. Simple arithmetic would be the wrong way to deal with 30x concentration, anyway. In fact, your analysis would destroy the entire “atmospheric window” if you were correct because it would end yup blocking the entire window.
If some initial concentration absorbed 30% (not “30 units” as you describe it), then increasing by a factor of “n” would lead to an absorption of 1 – (1-0.3)^n. For a 30-fold increase, the absorption would be ~ 100% (not “900 units”). This would be about identical to the ~100% absorption seen for CO2 (not 9 times stronger). (There would actually be important differences between blocking 99.99% and 99.9% , but that would be taking this even farther from the realm of analysis appropriate for a discussion like this.)
Tim Folkerts and Ira Glickstein
The normal interpretation of the graphs would be each taken as a pure sample at atmospheric pressure and temperature.
In the 15um region CO2 would absorb 100% of a beam of IR of this wavelength in a particular direction of length L
A pure sample at atmospheric pressure and temperature and at 15um region H2O would absorb 50% of a beam of IR of this wavelength in a particular direction of length L
When then combined to form air which contains 30 times as much H2O as CO2 then the logic of my post still stands.
But this is rather a distraction from the original post which Phil and Joel took exception to.
…..”What you appear to miss out in your layer model is the effects of thermalisation.
Lets start with CO2 the villain of the IPCC.
At atmospheric temperatures only around 4% are in active ready to emit 15um mode while the other 96% are ready to absorb.(Using MB statistics)
The plentiful 15um surface up IR is readily absorbed.
However the relaxation time length indicates that the chances of re-emitting are unlikely compared to loss by collision with N2 and O2 (99% of atmosphere).
This causes local heating (thermalisation)
Kirchoff’s Law does not hold strictly for this situation as significant quantities of thermal energy are passed on to non emitters.
Some of this energy can come back to CO2 by collision but emission of 15um as we get to higher altitudes becomes increasingly unlikely due to temperature drop.
A more likely radiative outlet path would be H2O which has several wavelengths >15um available.
This accounts for the large “bite” missing around 15um as shown in the Ian’s satellite “looking down” graphs above.
So the net result is slightly increased local troposphere temperature and shifting the radiating spectrum to longer wavelengths.”…..
Interestingly a similar discusion was happening at Claes Johnstons site
http://claesjohnson.blogspot.com/2011/03/simple-model-for-radiative-heat.html#comments
Here ScienceofDoom agrees that radiation has nothing to do with the temperature lapse rate in the troposphere.
20 mars 2011 06:01
ScienceofDoom sa…
Claes, why not read a few climate science textbooks of the last few decades?
The lapse rate in the troposphere – agreed by all – is determined by the adiabatic cooling as the pressure decreases. (Equally you can rewrite this equation as the conversion of potential energy to kinetic energy – i.e., the result of gravitation).
Nothing to do with radiation.
So who are you arguing with?
Bryan says:
March 21, 2011 at 4:50 am
I said about radiation around 15um
“We cannot then ignore the substantial H2O contribution.”
Phil. says:
…..”If it were a substantial contribution we couldn’t, since it isn’t we can.”…..
Ira Glickstein says above;
……”H2O also absorbs strongly in the ~15μ region”…. and produces graphs above to show this rather obvious conclusion.
Further since there are 30 times the number of H2O molecules to each CO2 molecule the net result is that the “bite” around 15um is primarily due to H2O.
Now why would Phil try to contradict this rather obvious conclusion?
Is it part of the IPCC proponents attempts to “demonise” CO2 -…. I think we should be told!
Because it isn’t an obvious conclusion to anyone who knows what they are talking about!
Below I have linked a series of MODTRAN spectra for the atmosphere which corresponds to the ‘Tropics looking down’ graph from Petty shown by Ira. The ‘bite’ in the 15 micron region is clear in the composite graph labelled ‘All’. In the second graph the contribution from H2O has been removed, the radiance on the high frequency side of the strong feature at 15 micron has increased but the ‘bite’ itself is unchanged (even the fine structure such as the spike at the center is still clear). The next graph shows the effect of eliminating CO2, the ‘bite’ is totally removed clearly indicating that CO2 is the cause. If you take my advice from above you can replicate this experiment for yourself using MODTRAN.
http://i302.photobucket.com/albums/nn107/Sprintstar400/Atmos.gif
Phil
Only someone from climate” science” could write this;
……….”If you take my advice from above you can replicate this experiment for yourself using MODTRAN.”……….
Do you not see the irony of the above
Imagine the scenario;
The teacher says to her pupils:
…….”Today we are going to do an EXPERIMENT to measure the acceleration due to gravity.”………
Take out your computers and carefully copy out your results.
There is no hope for a subject or people who play with a computer program and think they are carrying out an experiment.
I wish I knew more about the lapse rate. From what I have learned, ScienceOfDoom may be oversimplifying. Here is what I understand about 4 different “lapse rates”:
* the “dry adiabatic lapse rate” is approximately 9.8 C/km. It can be calculated from thermodynamics and appropriate gas laws. By definition, adiabatic means it does not transfer energy, so by definition it has nothing to do with radiation or conduction. This typically is applied to parcels of air that are rising or falling fast enough that conduction or radiation don’t make significant differences.
* the “saturated adiabatic lapse rate” includes effects of water condensation. When air reaches 100% humidity, condensation of water will have a major impact, This number is more complicated to calculate, but lower than the dry adiabatic lapse rate. Typical numbers are around 5 C/km
* the “environmental lapse rate” is the change in temperature for still air. This is typically around 6.5 C/km
* Finally, the actual lapse rate can have a wide variety of values, including inversions where the temperature RISES with rising elevation.
The fact that the atmosphere does NOT follow either the dry adiabatic lapse rate or the saturated adiabatic lapse rate is evidence that actual lapse rates have other influences. In fact, this quote from wikipedia clearly suggest that radiation is at least ONE factor in actual lapse rates.
“An inversion is also produced whenever radiation from the surface of the earth exceeds the amount of radiation received from the sun, which commonly occurs at night, or during the winter when the angle of the sun is very low in the sky. ” (from their page on inversions)
All that said, I DO agree that the actual lapse rate is indeed an important part of the temperature profile of the atmosphere.
Finally, all of this points to the fact that understanding climate involves considerable knowledge of a wide variety of topics. “Simple arithmetic” will not suffice. “Sound-bite science” will not suffice. Skimming through blogs will not suffice. High school physics will not suffice. To really understand this takes a career worth of work. The rest of us are just “Monday morning quarterbacks”. (And while such Monday morning quarterbacks may occasionally make a better call than the professional coach, that does no mean a Monday morning quarterback should be hired to coach the team.)
Bryan says:
Actually, the question is who ***YOU*** are arguing with since I don’t think that anybody here has been saying the lapse rate in the atmosphere is set by radiation (unless I missed it). However, it is technically wrong to say it has nothing to do with radiation…because it does have to do with the fact that the atmosphere is heated primarily from the bottom.
As I noted in a previous post, some combination of the dry and moist adiabatic lapse rates sets what is essentially the maximum lapse rate (because higher lapse rates than this tend to lead to convection which then lowers the lapse rate until marginal stability is restored). However, one could have an atmosphere where the temperature did not drop with height as fast as the adiabatic lapse rate…or even rose with height (as it does in the stratosphere). The reason, this does not happen on earth is that most of the absorption of solar radiation is at the surface…and most of the absorption of terrestrial radiation by greenhouse gases is also near the surface. (On other sites, I have seen arguments back-and-forth about whether eliminating the greenhouse gases alone would be sufficient to create an isothermal atmosphere…or whether we would still have the troposphere with its lapse rate, but I haven’t thought enough about it to have a strong opinion either way.)
If you are using “normal” as some sort of synonym for “incorrect” that first statement would be true. As has been pointed out to you, such an interpretation of the graph is simply wrong. I suppose it is an understandable mistake, although the arrogance with which the original argument was presented and now the unwillingness to acknowledge this error are are not very easy to understand. If you are unwilling to acknowledge when you are wrong, it is basically hopeless to carry on a discussion with you.
So, at this point, are you admitting that the bite out of the spectrum is due to the absorption by CO2? I am honestly not even sure what you are trying to argue anymore.
Tim Folkerts says
………”I wish I knew more about the lapse rate”………
Well here’s a good place to start.
This will give you a sound understanding of the importance of radiative transfer in the temperature profile of the troposphere.
http://rst.gsfc.nasa.gov/Sect14/Sect14_1b.html
Bryan says:
March 22, 2011 at 9:05 am
Phil
Only someone from climate” science” could write this;
……….”If you take my advice from above you can replicate this experiment for yourself using MODTRAN.”……….
Do you not see the irony of the above
No irony whatsoever, a university professor explains to a high school student how he can synthesize the spectrum of the IR radiation leaving the earth from space from the line by line database of the individual components. Then compare that spectrum with the observed one, when the excellent agreement is reached even down to detailed structure, the contributions of the individual components can be determined by repeating the procedure while systematically eliminating the components one by one. The student is too lazy to do this and decides to talk trash to the professor so he gets an F for the assignment, and still knows nothing about the subject!
Phil
I really think you have no idea what an EXPERIMENT is.
Perhaps you have never carried out a real experiment!
If your idea of an experiment is to juggle some predigested formula on a computer then you will only get the predictable result of; garbage in = garbage out, endlessly.
Perhaps in Climate Science courses there are no real experiments – that would explain why so much rubbish is produced.
Phil’s EXPERIMENT to verify Mann’s Hockey Stick.
Get computer, get Mann’s temperature series, plot the graph.
Surprise surprise a hockey stick!
Just to be sure Phil repeats the EXPERIMENT the following week.
Unbelievable!!!…… Phil gets exactly the same result.
Another triumph for Climate Science.
Phil wonders why Physics and Chemistry students don’t follow the Climate Science model, just think of the money saved on provision of laboratories.
A further bonus is that awkward results will ever be produced.
Phil. says:
Ira Glickstein
John Marshall says:
A very complicated and flawed article.
Sjoerd says:
Ira,
Please leave out the “degree” when talking about Kelvin. It’s “degree Fahrenheit” and “degree Celsius”, but it’s “Kelvin” (without the “degree”). Same when abbreviated: It’s 270K, not 270ºK.
Small mistakes like this distract from the article and undermine your credibility: If one can’t get simple details like proper usage of units correct, …
I said
Ira Glickstein
..”You seem to think that an ordinary blanket is unlike an electric blanket in effect to radiation, perhaps you think it does not radiate?
For the record an ordinary blanket is a better radiator than for example the atmosphere.”….
It seems the only enthusiastic supporters of the article are all rabid CAGW proponents.
Joel Shore regularly turns up at WUWT as a spoiler.
In a blog to another CAGW supporter Arthur Smith Joel bragged about his unstinting efforts to disrupt this sceptic platform.
However Joel is more famous (or infamous) for going into print in attacking Gerhard Gerlich and Ralf D. Tscheuschner(1) in a paper for things they didn’t say.(4)
Phil thinks you can do EXPERIMENTS on a computer.
There is little hope for such a level of confusion.
Ira I would respectfully suggest that before your next article you revise your thermodynamics undergraduate work .
After that you will appreciate that reference (1), is a traditional critique within the frame Of Physics of some current nonsense underpinning the current IPCC position”
[1] “Falsification Of the atmospheric CO2 greenhouse effects within the frame Of Physics” by Gerhard Gerlich and Ralf D. Tscheuschner; International Journal of Modern Physics B, Vol. 23, No. 3 (2009) pages 275-364.
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf
[2] “Proof of the atmospheric greenhouse effect” by Arthur P. Smith; arXiv:0802.4324v1 [physics.ao-ph]
http://arxiv.org/PS_cache/arxiv/pdf/0802/0802.4324v1.pdf
In this paper Arthur Smith defends the current IPCC position and has the merit of taking issue with G&T for something that they did say.
[3] “Comments on the “Proof of the atmospheric greenhouse effect” by Arthur P. Smith” by Gerhard Kramm, Ralph Dlugi, and Michael Zelger; arXiv:0904.2767v3 [physics.ao-ph]
http://arxiv.org/ftp/arxiv/papers/0904/0904.2767.pdf
Takes issue with Arthur Smith
[4] Comment on ‘Falsification Of the atmospheric CO2 greenhouse effects within the frame Of Physics’ by Joshua B. Halpern, Chistopher M. Colose, Chris Ho-Stuart, Joel D. Shore, Arthur P. Smith, Jorg Zimmermann.
This must be the most embarrassing paper in history as it attacks G&T for things they didn’t say.
Joel will give you a copy on the other hand I will understand if he doesn’t.
[5] “Reply to ‘Comment on ‘Falsification Of the atmospheric CO2 greenhouse effects within the frame Of Physics’ by Joshua B. Halpern, Chistopher M. Colose, Chris Ho-Stuart, Joel D. Shore, Arthur P. Smith, Jorg Zimmermann” by Gerhard Gerlich and Ralf D. Tscheuschner, International Journal of Modern Physics B, Vol. 24, No. 10 (2010) pages 1333–1359.
http://www.skyfall.fr/wp-content/gerlich-reply-to-halpern.pdf
G&Ts reply to the absurd [4]
Bryan says:
March 23, 2011 at 8:23 am
Phil
I really think you have no idea what an EXPERIMENT is.
By your own statements here it’s obvious you don’t!
If your idea of an experiment is to juggle some predigested formula on a computer then you will only get the predictable result of; garbage in = garbage out, endlessly.
Clearly your reading comprehension is lacking, what was described was not the use of a ‘predigested formula’ (whatever that is supposed to mean?) Rather the use of an extremely detailed database of molecular spectra, painstakingly compiled by physical chemists, to identify the source of the features in a measured spectrum. This is something that is done in experiments by chemists all the time, it is the reason that such libraries of data are compiled in the first place. Phil
wondersknows why Physics and Chemistry studentsdon’tfollowthe Climate Sciencethis model, just think of the money saved on provision of laboratories by being able to access libraries of data. You thought it was an acceptable approach when you handwaved using very low resolution spectra, but dropped it when shown using accurate data that your conclusion was wrong!Bryan says:
March 21, 2011 at 2:46 pm
Look up at Ira Glicksteins graphs above.
Lets say you give the CO2 graph amplitude of 100 units in the region of 15um.
Next look at the H2O graph in the same region.
I make it out to be about half that of CO2 lets say 50 units.
[personal insults omitted] I will reduce the H2O magnitude to 30 units.
Now comes the arithmetic are you ready…..
There are 30 H2O molecules for every CO2 molecule.
30 x 30units for total H2O effect = 900 units
CO2 contribution = 100 units
So H2O has about 9 times the radiative effect of CO2 around 15um.
Having lost the argument on the point of this thread you then obfuscate by dragging in irrelevant off-point, straw man arguments and personal insults.
There is of course no point in arguing with such a committed know-nothing since you have no chance of convincing him on the science, however it’s important not to let such rubbish go unrebutted in case other readers might think it has merit.
Phil says
…..”There is of course no point in arguing with such a committed know-nothing”….
………then complains of personal insults!
He goes on;
….”reason that such libraries of data are compiled in the first place.”……
When you look up data you are not conducting an experiment!
You are reading!
An experiment is an open ended investigation and has the possibility of falsifying a conjecture.
A good example discussed on this thread is the experiment by R W Wood where he showed that contrary to the popular opinion at the time;
1. A glass “greenhouse” works by stopping convection rather than by a radiative effect.
2. The radiative effects of atmospheric gases can be ignored for most practical purposes.
Karl Popper is credited for the “falsification test” for a conjecture by experiment.
An experiment to prove that the present IPCC global warming is real however cannot be proved one way or another.
This shows it is a religious belief beyond the powers of experimental falsification.
IPCC adherents have confidently made predictions only to find exactly the opposite happened in fact.
Undeterred they then said the opposite conditions also proved AGW.
This is why Phil has difficulty with the idea of an experiment.
This is unfortunately no cure for such a mental straitjacket.
Bryan says:
Bryan, could you kindly provide me with the link or reference to where I actually said that?
You have made this claim repeatedly but have yet to back it up. In particular, please tell us what Gerlich and Tscheuschner did say regarding the atmospheric greenhouse effect and the Second Law. It is easy for you and G&T to make these claims that we have mischaracterized their arguments if you or they are never required to explain what those arguments actually are and how they are still sensible and consistent once one considers the radiative transfers that occur in both directions.
Bryan says:
March 24, 2011 at 10:32 am
Phil says
…..”There is of course no point in arguing with such a committed know-nothing”….
………then complains of personal insults!
“As ye sow, so shall ye reap”, actually the above is a good description of you based on your posts here, you know very little about the subject and obstinately refuse to acknowledge your errors and usually change the subject with an inapt analogy!
He goes on;
….”reason that such libraries of data are compiled in the first place.”……
When you look up data you are not conducting an experiment!
You are reading!
Something you evidently have difficulty with.
An experiment is an open ended investigation and has the possibility of falsifying a conjecture.
Exactly, which is what I did to falsify your hypothesis that the ‘bite’ at 15 microns was due to water. I conducted the experiment of constructing a synthetic spectrum from the database of experimentally determined spectra of pure compounds taken under controlled conditions and then compared that with the measured spectrum under discussion and obtained excellent agreement. I then progressively removed the contribution from each compound in turn in order to see which was responsible for the feature at 15 microns, and found that it was CO2 thus falsifying your hypothesis. A combination of synthesis and analysis, I even told you how you could reproduce the experiment but you declined. Had you been correct in your hypothesis my experiment would have showed it to be so.
Karl Popper is credited for the “falsification test” for a conjecture by experiment.
Which is what I did!
This is why Phil has difficulty with the idea of an experiment.
This is unfortunately no cure for such a mental straitjacket.
As shown above I have no such difficulty, the one who has the straitjacket is clearly you with your habit of lashing out at any rebuttal of your points and dragging in unrelated issues to obfuscate (as shown above with the irrelevant IPCC reference).
The cure for your purblindness is to open your eyes and examine the evidence and learn something about the science.
Ira Glickstein
I kind of like what Bryan says on March 24, 2011 at 2:16 am. However, all the same, I am looking forward to reading your next essay written just as you think it should be written.
Personally I have by now realized that I may just as well go with the AGW flow as I have no more possibility of disproving it than I have of watching a “Pigs Flying Circus”.
It seems that people do not know the difference between “Heat, Temperature and Energy, and furthermore do not know what “Advection” is. Nor do they seem to comprehend that there is adiabatic warming of air as well as cooling. One should therefore not be surprised if they accept the claim that “IR-thermometers” show levels of radiation.
Yes, – as ‘Advection’ happens within the ‘Earth System’ it can therefore only equal zero. True enough but so also does any radiation between the surface and the atmosphere and therefore ‘it’ must also equal zero. Except in the case of the latter, half the energy stored must leave for a life in outer space and therefore, must equal 0.5
In closing I ask you, as you seem to be very exact in explaining the GHEffect, to explain to me what difference it makes whether the back radiation trick from GHGs is performed by 390 ppm or 1000000 ppm of GHGs.
In other words; If 324 W/m² is emitted from the surface to the atmosphere, (irrespective of solar irradiation) then 324 W/m² must be radiated back to the surface in order for the earth not to cool. But 324 W/m² is all that can be “back radiated” never mind how many CO2 or other GHGs are employed in that particular ‘Post Office’
O H Dahlsveen says:
First of all, a correction: As the diagram shows, the earth’s surface emits more than 324 W/m^2…It emits 390 W/m^2. (Not all of that is absorbed by the atmosphere, but 350 W/m^2 is.)
Secondly, I am not sure where you are getting the idea that 324 W/m^2 is all that can be back-radiated. If there were more GHGs, more would be back-radiated. Perhaps what is confusing you is that you think this would upset the radiative balances that exist. However, that is only true if we try to change the 324 W/m^2 number without changing any of the other numbers. However, in reality, other numbers would change too…the amount radiated from the surface of the earth, for example, as well possibly others like the amount due to latent heat and thermals.
In particular, let’s do a thought experiment by instantaneously doubling CO2 concentrations. Then what would happen is that the effective radiating level from which emission escapes to space would increase and because temperature drops with height in the troposphere, that would mean the emission is occurring from colder places and would correspondingly be less. (about 4 W/m^2 less, as it turns out). Thus, the earth system would find itself emitting less the ~235 W/m^2 that it absorbs from the sun and as a result, energy would start to accumulate, causing the system to warm. It would warm to the point where radiative balance is restored. And then, with the earth’s surface now at a higher temperature, it would radiate more than the current 390 W/m^2.
Phil , Joel Shore and others.
This recent presentation touches on a number of topics recently discussed in this thread.
Your evident confusion about the:-
radiative effects of CO2 on the climate;
climate models;
falsification, or not, of the greenhouse theory is addressed.
I hope you can understand at least some parts of the lecture.
http://hockeyschtick.blogspot.com/2011/03/geophysicist-explains-how-sun-controls.html
Brian, you might like this thought. See if this falsifies to you the equal ‘back radiation effect’ underlying the Greenhouse Effect that underlies the Global Warming by CO2 movement (sometimes called a theory or a hypothesis).
http://i56.tinypic.com/6r3ok6.png
I’ve tried to make this effect as visual as possible hoping that maybe you and others can see what I am talking about.
• When a photon leaves the surface it cools the surface by the energy held by that photon. If not immediately ejected to space in the radiative window frequencies, it will be absorbed by some molecule warming the atmosphere by that same quantity of energy. From that moment forward that quantity of energy can never further warm the atmosphere no matter how many times it is absorbed and re-radiated or thermalized and thermally re-excited or even split to different molecular species. In many respects this bouncing about is merely fast and long-reaching conduction from molecule to molecule separated by many meters.
• Once it obtains an altitude of a few free path lengths, that energy is statistically committed to space eventually. That tiny upward tendency because we live on a sphere means it can only very, very rarely return to the surface to cool the atmosphere and re-warm the surface. If we lived on an infinite flat plane, as on a flat Earth, that small green vector does not exist, only (and always) on a sphere as are all planets with atmospheres.
• Actually, the only radiation received at the surface from above has it’s origin very close to the surface, within a couple of hundred meters. One exception to this is when warm clouds radiate and a portion is in the radiated window frequencies and allows the clouds to radiate downward to the surface rather freely.
• Also, since the free path length (and therefore the tangential component) grows with altitude due to the decrease in pressure and density, this tiny effect grows larger and larger the further and further upwards that energy is carried.
— Much like in Vegas, the house(geometry) has the cards stacked against any downward radiation from the atmosphere back to the surface and it is because of the limited free path length and being on a sphere. As I’ve said many times, you cannot “trap” energy within a gravitationally held, open-ended, atmosphere about a spherical planet.
Brian, a couple of things not said above.
First, that graphic http://i56.tinypic.com/6r3ok6.png is of course hugely exaggerated. That factor is too small by itself to draw to scale and at higher altitude (greater that 500 m) where it becomes more prevalent and higher total.
Second, the atmosphere is, on the average, and locally, homogenous therefore all tangentially oriented vector components can be cancelled except for that tiny green upward component. That upward component is all that is left after horizontal cancellations and is the crux of my thoughts.
Thirdly, this might seem so very tiny, many digits of precision removed, but you need to multiply this effect by both the number of GHG molecules in the atmosphere and by the number of jumps made before that energy finally makes it’s way to space.
Was just didn’t want the essence of that thought to be muddied by some trivially known logical factors.
wayne
The radiative effect of CO2 on the atmosphere is as R W Wood demonstrated very small.
Your vector diagram and gravity all point to “up” as being favoured compared to “down”.
As you point out only near the surface is the flat earth approximation valid.
Further as temperatures drop MB statistics favour longer wavelength emissions.
Only above the troposphere do temperatures start to increase in a very thin atmosphere favouring unimpeded radiation to space.
Thermalisation of earth “up” radiation results in local temperature increase favouring an increased convective push in the “up” direction.
However this nasa paper on the tropospheres lapse rate does not even include radiation as even a minor factor.
http://rst.gsfc.nasa.gov/Sect14/Sect14_1b.html
Bryan says:
March 26, 2011 at 9:48 am
Phil , Joel Shore and others.
This recent presentation touches on a number of topics recently discussed in this thread.
Actually it doesn’t!