“The influence of IR Absorption and Backscatter Radiation from CO2…”
Kevin Kilty
A recent paper, describing an experiment purporting to be a laboratory model of the Greenhouse effect was mentioned several times recently on WUWT (February 6 and February 20) as one worth reviewing. The paper is open source, and may be found here.
Lately a brief discussion of this paper showed up on several threads on JoNova’s site. This prompted me to look at it in detail. While not saying much about the Greenhouse effect the paper does provide a couple of good lessons about experimental design, the Stefan-Boltzmann law, and peer review. Here is a brief overview.
Apparatus and operation overview
Figure 1, adapted from the paper shows the experimental apparatus. It consists of a box made of bright aluminum foil-covered styrofoam, sealed on its front by a thin EDTA film, and at the back end by nonfoil-covered styrofoam. The EDTA window allows an IR sensor a view toward the rear of the apparatus. This back end has a thin aluminum plate centered on it. This plate is heated by a lamp to a temperature near 100C. It also has a small 6×6 cm window of EDTA to allow a second IR sensor a view forward. The apparatus is divided into two compartments separated by another EDTA film. Both compartments have a small opening in the top so as to maintain constant pressure irrespective of temperature and each compartment contains a small fan to circulate air vigorously enough to maintain a constant temperature throughout.
When the apparatus is in operation the aluminum plate at 100C radiates IR and causes the rear compartment to reach a steady temperature of about 46C. The authors “compute” the irradiance of the back surface using the Stefan-Boltzmann law. When the front compartment is filled with air all of this “computed” IR power is supposed to exit the front window.
This experiment is now repeated with the front compartment filled with 100% CO2. Now emitted IR radiation from the aluminum plate is partially absorbed by CO2 raising the temperature of the front compartment to around 33C. This causes radiation passing through the front window to drop temporarily. The missing IR is presumed to be redirected or reflected toward the rear compartment. This should raise temperature of the rear compartment, and this increasing temperature should return the front exiting radiation to its original value. However, when the experiment is run no increase of temperature of gases in the rear compartment is observed, nor does the back surface of the rear compartment show a temperature increase. The claim is made that this null result casts doubt on the currently accepted explanation of the Greenhouse effect. This null result is bolstered by an energy balance computation being unable to locate any wayward energy transfers.
Analysis of this as an experiment
There are three separate issues to clarify in this experiment. First, there is the construction and calibration of the IR sensors. Second, there is the energy balance calculation which searches for, but cannot locate leaks of energy to explain the null result. Third, there are the many explicit and implicit uses of the Stefan-Boltzmann formula which are erroneous, and which cast doubt not on the Greenhouse effect but on the null result here.
Sensor construction and calibration
The sensor is a thermopile built by TE Connectivity (TS105-10L5.5MM thermopile sensor). Its data sheet can be found at the manufacturer’s site. The sensor contains in addition to a thermopile, a highly accurate negative temperature coefficient (NTC) thermistor to aid in building a temperature compensation circuit. It is widely accepted that a small object composed of any material what so ever, and a larger containing enclosure will not transfer net radiant energy between them when they have the same temperature. In fact, it would violate the second law of thermodynamics otherwise. A temperature compensating circuit is needed to force this constraint on the sensor as otherwise ambient temperature of the thermopile will confound its measure of radiant energy. Figure 2, from the manufacturer’s cut sheet, shows the transfer function of this sensor at a 25C ambient temperature. Note that the output of the sensor passes through zero at ambient temperature as it must.[1]
The authors built an amplifier with a voltage gain of 120 to raise the sensor signal to a level reasonably read with a voltmeter; and they calibrated their instrument by using it to measure blackbody radiation emitted by a blackened iron pan. They describe the process thusly.
“We used a black iron pan, filled with water of temperature 100C and allowed to fall to 15C. We measured temperature of the iron pan with a Fluke 62 Max IR thermometer, and the voltage output of the detectors was measured with a digital voltmeter….We computed the IR energy output using the Stefan-Boltzmann Law.” [emphasis is mine]
We presume that ambient temperature must have been no higher than 15C as this is the lowest temperature obtained in the calibration run. Their resulting transfer function, shown in Figure 3, unfortunately shows a sensor output of 25mV at 15C rather than zero. Thus their sensor is biased, and the bias is nearly 20% of the full range (120mV) they expect to measure — a very large bias at low signal levels, indeed. How this bias came to be is a mystery because they do not fully explain their circuitry construction. It may be an offset voltage amplified by their high-gain amplifier; or it may result from a failure to use temperature compensation available.
One other problematic issue with this sensor involves its field of view (FOV). The authors’ expectation is that the FOV is plus or minus 5 degrees, but the manufacturer’s data clearly shows that the full field of view is plus or minus 15 degrees. At least a quarter of the energy falling on the thermopile comes from beyond 5 degrees. Obviously there is a discrepancy between what the authors believe the sensor “sees” and what it actually does. This will lead to problems when the sensor is used with the apparatus when its view is unlike that of the blackened pan used for calibration.
Energy balance
Despite an effort by the authors to perform a thorough energy balance looking for unexpected leaks of energy, no completely credible energy balance is possible for the following deficiencies:
- We do know neither the thickness of the EDTA film nor the thermal conduction coefficient of the EDTA film plus air film at its surface. Yet, because the film separates warm gas from ambient air in several places, there must be heat transfer between the compartments or out of the apparatus entirely by conduction through the windows.
- If fans are installed in the compartments, then these act to dissipate electrical energy, but this dissipation is not specified.
- The openings meant to maintain constant pressure are also potentially sources of infiltration, but no estimate of this is made.
- We are told the EDTA film is about 90% transparent to light and IR, but we do not know if the remaining 10% is reflected or absorbed or a combination of both.
One can only conclude that there are many sources of uncertainty in the construction of the apparatus and in the construction and calibration of the sensors. These uncertainties are often additive and may reach a magnitude of 10% each.
Misuse of Stefan-Boltzmann
The Stefan-Boltzmann relationship applies to cavity radiation. A cavity has only a small connection to the outside world just large enough to make measurements of the radiation field inside. It is isothermal and behaves the same independently of what material it is made from.
The apparatus here is not a cavity. It is transparent on one end and partially so on the other. Having a substantial fraction of its surface transparent means that placement of materials and their detailed radiation characteristics matter.[2] The first order of approximation to IR radiation from something that is not a cavity, and not isothermal, is to use the Stefan-Boltzmann law, but to assign appropriate emissivities less than 1.0 to different materials. The blackened aluminum radiator has an emissivity close to 1.0. It is perhaps 0.96, but the bare styrofoam is far from black at IR wavelengths. An accepted estimate of emissivity of this material is 0.60; i.e. at any temperature it will radiate only 60% as strongly as the Stefan-Boltzmann law predicts. The aluminum foil has a low emissivity probably around 0.04. Its whole purpose is to not radiate IR. We don’t know about the EDTA film.
The authors calculate that at steady state running, with the aluminum plate at 100C and the back surface styrofoam at 46.5C, the total irradiance (emitted power) of this surface is 107W. They use the Stefan-Boltzmann relationship to calculate this. However, taking emissivity of the materials involved into account the emitted power is only 80W.
The front sensor view of this back surface is not limited to a FOV of 5 degrees but is wider and so it captures unknown fractions of blackened aluminum and styrofoam. In fact it may be so wide as to view some of the aluminum covered styrofoam on the sides of the apparatus. This is nothing like the circumstances under which the authors built their calibration curve. The view of sensor 2 deviates even more from the calibration circumstances.
Thus, not only does the calculated irradiance seem in error by about 20% over erroneous use of the Stefan-Boltzmann law, but the known bias of the sensor combined with the issue of the calibration curve not pertaining to a view like that of the back plane of the apparatus, means that all the calculations and measurements are more interesting than they are believable.
One additional error in applying the Stefan-Boltzmann law occurs in the translation of the calibration transfer function to an irradiance value. The calculation mentioned in the quotation about the calibration procedure implies a one-way transfer from the blackened pan to the sensor, when in fact the transfer is two way between the sensor and pan.
One more issue is important. The gas in the front compartment, even when composed of 100% CO2 is not a blackbody. Engineers involved in furnace calculations have developed correlations from experiments by which to estimate the effective emissivity of combustion atmospheres. From these a person can calculate that an atmosphere containing 70 cm of 100% CO2 at a pressure of 100kPa has effective emissivity of about 14%. Once this gas absorbs its limit of 14% of IR from the back compartment (i.e. 14% of 80 watts) and reaches an equilibrium temperature it does not reradiate this backward, but rather in all directions. It is reflected many times from the aluminum foil, with 4% being absorbed with each reflection, some passes out the front EDTA window, some passes the intermediate EDTA window and reaches the rear compartment. This could easily be only 10% of what had been absorbed in the front compartment. The gas in the rear compartment contains so little CO2 that its emissivity (which equals its absorptivity) is probably in the neighborhood of only 1%. Thus, the null result of this experiment, rather than being a surprise, should be entirely expected.
Lessons learned
The null result of this experiment seems reasonable, but it says nothing about the Greenhouse effect.
The journal involved, one in the SCIRP family of publications, is peer-reviewed. Yet consider the effort one has to employ to review this article in a technical sense. The reviewer ought to have some expertise in transport calculations, especially radiation transport in enclosures, but also metrology and electronics. It is not reasonable to expect that all reviewers have the time or resources to do a job much beyond making sure a submitted paper meets minimal standards of scholarship. There are now too many papers submitted for the number of people willing to review. The lesson is that even in peer reviewed journals caveat emptor applies.
The authors build confidence in their work along the way with approximate calculations, and one might wonder why this consistency does not trump my alternative findings. I can only answer that there is something like a corollary to Murphy’s law which applies very broadly: There are many wrong ways to approximate and measure something, and they can all be made to agree with one another and with expectations.
Nothing substitutes for a critical, and sometimes brutal, independent review.
Notes:
1-Another way to look at this is to recognize that at equilibrium the sensor gathers radiation through its field of view and at the same time radiates back to its surroundings.
2-As an example a thermograph in Figure 4 below is of a brushed stainless beverage cup with a matte black cowboy icon printed on it. The cup is isothermal but the thermogram shows the printed area to appear much hotter than the brushed stainless. It is all a matter of the effective emissivity of the surface materials. Most of the apparently warm streaks on the cup are the reflections of warm objects in the surroundings.
Everyone is a critic… Why any definitive experiment has ever been proposed here that can finally prove the supposed CO2 greenhouse effect ? Answer : Greenhouse effect has never been formulated within the frame of Physics. The T^4 used by the climat models is a traversity, since greenhouse gases are neither “body” neither “black”, voiding the theory.
T^4 is engineering not conjecture.
We’ve been measuring the emission and absorption spectra of gasses for longer than I’ve been alive.
Having said the above, it’s hard to call a gas a black body because it absorbs and emits at specific wavelengths.
T^4 does not apply to gases. You contradicted yourself.
http://www.ptep-online.com/2014/PP-38-07.PDF
Saying that gasses can not act as black bodies, which is what your link points out, does not negate T^4. The Stefan-Boltzmann formula has a term for emissivity. In other words, even gray bodies are governed by T^4.
The question is whether a gas can generate a black body spectrum. Most gases can not. Water, however, has an absorption/emission spectrum that spans enough of the lwir range that it can effectively produce a black body spectrum.
? Do you know how much solar insolation under clear sky conditions is absorbed by w/v?
Water is pretty much transparent at visible wavelengths but starts absorbing as you go deeper into infrared. link Given that the top of atmosphere solar radiation is around 1300 watts per square meter and at ground level it’s something like 1000 (under cloudless conditions), that means somewhere around 300 watts per square meter doesn’t make it to the ground. That sets the maximum of what water vapor could be absorbing.
I’ve seen the figure of 23% of incoming solar radiation is absorbed by air, ozone, water, clouds and dust.
Without doing a lot more digging, I would say that water vapor contributes a very significant portion of the solar radiation absorbed by the atmosphere.
Gases are quantum emitters and do not emit radiation estimated by the S-B law – they are not black bodies or gray bodies.
http://web.ihep.su/dbserv/compas/src/einstein17/eng.pdf
See equation 49 in https://www.hindawi.com/journals/ijas/2013/503727/
Based specifically on Einstein’s theory of radiation, the author derives the very close relationship between spontaneous emission of gases and the Planck black-body spectrum. Gases may absorb and emit in defined bands, but within those bands, intensity scales with temperature just like any other radiator. They are, in fact, gray bodies.
All matter is a quantum emitter; that doesn’t differentiate gases.
The author of the paper offered shows some indications of being a crank. There’s a lot of referencing his own work going on. And, this statement is outrageous: “Gases primarily respond to energy by channeling it into trans- lational (not simply in their vibrational, rotational, or elec- tronic) degrees of freedom.” This violates maximization of entropy.
Colour me ignorant. I admit I haven’t a sufficient background to understand this comprehensively. Neither do climate “scientists: apparently.
Why can we not measure the change in temperature at different altitudes in the atmosphere from night to day to determine the absorption at different atmospheric densities and latitudes and work out from that what the total daytime absorption is?
We must have spent a lot more than that on models by now and they haven’t moved the predictive needle for over 40 years in terms of RCP. Is empirical measure so “yesterday’?
In sort, they need to do a better experiment.
Way back to before Tyndall, experiments that purport to measure the greenhouse effect of CO2 have suffered from the same problem which is that CO2 does not absorb and emit as a black body, but rather at specific wavelengths.
It’s kind of like desktop fusion where they measured something but it sure wasn’t fusion.
But regardless of the inaccuracies and misuse of the SB formula, they apply to both the control and the actual experiment, so while they might not give accurate quantitative results, they do give qualitative ones and more importantly comparative ones.
I havent heard of this experiment, but you cant disregard it so casually.
This was exactly my thought. Anyone please feel free to correct the errors of this experiment and show us the purported back radiation effect of IR active gases.
So I sent many emails to this site asking about this experiment. I was intrigued because they set out to prove the idea that CO2 was a major greenhouse gas that controlled climate and they found that their experiment went against their expectations. It sounded like science.
I might be naive and definitely not a scientist but I think most commentators here missed the result of the experiment.They found that to their surprise, I think . CO2 was not a major control knob for climate temperatures.
I enjoy this site very much but there seems to be a tendency to disregard good work from people who don’t drink the local kool-aid. This was an actual experiment for crying out loud. When does that happen in the field of climate science.
I say do an experiment like theirs that proves them wrong ( or right) and stop staring at intellectual navels.
I don’t fault the authors for trying to do an experiment, but I do fault them for lack of care in execution. You cannot take the results of an experiment done wrong in a number of ways as meaning much of anything.
Neil, it seems you don’t understand the head post. It points out a number of real-world, physics-based errors in their experimental setup. It lists each error, and explains in detail why it is wrong.
This is as far from intellectual navel-gazing as one can get.
We didn’t “miss the result of the experiment.” We’re discussing the errors and the problems with the experimental setup that invalidate the experimental result.
Best regards,
w.
w
I am a big fan of yours and enjoy the clarity and humour you bring to your posts. Even to the extent that I refer to my wife of 50 years as my ex high school sweetheart .
I am not sure if the review done here ever gets back to the original writers of the paper for their opportunity to defend their ideas and make further comment. If they do not get that opportunity, and the review remains on this site then I think that is a problem since I as a science fan thought that was how progress was made. So I accept that I don’t understand the “physics based ” errors but I am sure the original authors might, and may have counter arguments. Who knows? Without that discourse I may have to stick with my” navel gazing” comment since the review is not being seen by the right people.
As far as I can see, the experiment does a reasonable job of emulating the IPPC / NASA / every university’s version of the GHE theory. The use both the SB equation and the IPCC’s version – and still find no heating. What’s more they admit they are puzzled by the result.
There is no point is saying that is not significant in view of the money involved – $trilions.
Believers in the GHE really have to step up and show its warming effect unambiguously.
And maybe while they’re at it, they’d like to show radiative fluxes being added together to produce a temperature greater than either flux is capable of on its own.
Radiation flux is really a radiation density – and there’s no way you can add one radiation density to another without getting absurd and results that wind up with infinite temperatures.
Think concentric spheres or pipes with the outer one hot. The inner has to become infinite if you can add radiative fluxes. Either one flux dominates or the other does – you cannot add them together.
But as someone said, one experiment could prove me wrong.
Zagzigger said:
Suppose you are standing near a fire before dawn. The air is cold, but you are warmed by the radiation from the fire.
Then the sun comes up. Solar radiation hitting your body is added to the radiation from the fire, and you get warmer than you were with just the fire alone.
So yes, Zagzigger, radiative fluxes DO add, and they don’t end up with infinite temperatures.
w.
With respect, I don’t think that would qualify as a test.
Try this:
No new equilibrium can ever be reached because the temperature of the target must always be higher than that created by the Sun alone or H alone. And that statement will drive the temperature to infinity.
Note also that also by definition of the flux-add mechanism, the heat source H will be able to raise the temperature of the target to a higher level than its own temperature. Something not seen every day.
As originally said, if heat-fluxes could be added, then with concentric pipes or spheres, with the hot one on the outside, the flux must add / concentrate at the inner surface. If the inner pipe or sphere is small enough, that temperature caused by the concentrated flux will tend to infinity.
Don’t think so.
Willis is stating the Ist law of thermodynamics — to analyze a system/control box one accounts for & then adds/subtracts ALL the various heat/energy fluxes (radiation fluxes are energy). This is fundamental.
OK let me run this argument again using numbers:
Assume an ambient temperature of 20C.
Let’s say the Sun creates a temperature of 40C at a target.
Separately, let’s say a local heat source of 35C can create a temperature of 25C at the same target.
Start with just the Sun and let the system reach equilibrium at 40C.
Introduce the local heat source of 35C.
Now, according to the flux-add/ GHE, the temperature of the target has to rise with the increased flux.
Let’s say it rises to 42C.
So now we have the situation where a source of 35C is able to increase the temperature of another object from 40C to 42C.
Well, I’ve never seen such a thing – and I doubt whether anyone else has seen anything like it either.
Note how eerily reminiscent this is of the assumed “real GHE”.
In that mechanism, supposedly running between the Earth’s atmosphere and surface (and believed by everyone) something at a low temperature (atmosphere at -30C) is able to increase the temperature of a target (Earth’s surface) which is already at a much higher temperature (-18C or higher).
Too fantastical for me.
I think believers will have to demonstrate this in a lab before anyone with any sense will believe it.
What you see here is a violation of the 2nd Law of Thermodynamics – the most tested law in all science.
If you prove fluxes add, you disprove the 2nd Law – good luck.
You demonstrate your ignorance. Anyone who invokes the 2nd Law in this type of analysis proves that. The 2nd Law has absolutely NOTHING to do with this issue. The 1st Law is what is needed & ONLY that because it’s all about and only about energy balances.
Well, I wasn’t expecting that reply.
So, you’re saying that you can raise the temperature of something already at 40C to 42C by introducing a source at 35C.
That’s the most amazing thing I’ve ever heard.
If you manage to do that, or something like it, you will be in the science reference books for ever more.
And what’s more, you don’t believe that has anything to do with the 2nd Law.
I cannot think of a reply – sorry.
You’re getting confused by your own construction of this exercise, I think.
The sun does not “create” a temperature in the target – at equilibrium the target will assume some temperature. This temperature will be the temperature necessary to balance all radiative inputs (radiant power being proportional to temperature). Increase the radiative inputs and you will increase the equilibrium temperature necessary to balance them. This does not violate the second law – heat will always be flowing from the warmer object to the cooler. In fact, if we imagined a scenario where the target object was absorbing incident radiant flux but no energy was imparted to the target by this flux, that would violate the conservation of energy.
Please see my reply to beng135 on the same issue.
If you also think you can manage to raise the temperature of something already at 40C to 42C by introducing a source at 35C – then I’m left speechless.
My advice it to do it or something like it – a Nobel Prize will be just the start.
Amazing, just amazing.
The air in my house in only 62 degrees F, while my body is 98.6 degrees F, but I am certainly warmer in my house than I would be floating through an empty vacuum in space with no starlight.
Lots to unpack in your proposed exercise. To start with, if H is able to independently increase the temperature of T then H must be hotter than T when the two bodies are in radiative equilibrium assuming some distance x between the bodies. Therefore coupling T and H will cause T to warm via conduction until it reaches equilibrium with the reservoir.
Please see my reply to Beng135.
Thanks
I cannot assume that the solar radiation hitting my body from the sun is “added to” the radiation of the fire, because if the radiation from the fire is more than the radiation from the sun, then I would not feel the sun’s radiation. The fire’s greater radiation would dominate what I felt.
Now if the atmosphere warms because of the sunrise, and the air around me and around the fire becomes warmer, then, yes, I can see being warmer. Or if the sun radiation hits my back, while the fire radiation hits my front, then, yes, I will be warmer, but NOT because the fluxes add together, but because radiation is now hitting a GREATER AREA of my body, thus stimulating a greater number of heat sensing nerves/brain-areas.
“Believers in the GHE really have to step up and show its warming effect unambiguously.”
Just like believers in healing hot springs have to step up and show the healing results unambiguously?
Don’t understand that comment – but it reminds me of something that has bothered me for ages. Every university in the world must have tried to prove the GHE because success would mean multiple Nobel Prizes for the VC, the experimenters, the department, the politician in charge of Educations etc.
But we see nothing. Failed experiments are very important in physics, and if they are not reported it must be regarded as dishonesty.
The RGHE gaslighter fightback begins, been too many articles just lately throwing the holy-grail into doubt, the luke-warmers are out to correct all your wrong think.
Excellent review and critique. Especially with regards to field of view and emissions/(reflections) at all angles.
“4. Discussion
Many references in the IPCC reports refer to the forcing of increased IR radiation on the temperature. This factor is much discussed [19] [20]. Our results show that the formulas used by IPCC Equation (1a) and Equation (1b) should give very large temperature changes.”
Utter nonsense. Equation (1a) is not applicable to a 1 meter thick atmosphere.
No kidding, the earth is not a greenhouse.
No roof….
hmmm…. time to redo greenhouse experiements with the roof removed?
I like experiments that have tangible (or even edible) results … https://newtube.app/user/RAOB/QiZ0C6Z
You come to us for hope. How dare you.
First, come up with a peer reviewed proposed experiment?
And take it from there.
Their sensor had to VERY VERY COLD – liquid Nitrogen temperature for starters
Even NASA know that
Somehow I get the impression they have detected ‘radiated cold’
As a kid I thought that is what happened, especially when the Moon was visible.
I proved conclusively with empty Ribena bottles, refilled completely with water and left outside, overnight, where the Moon could see them.
Sure enough next morning, the Moon had froze the water and broke the bottles.
I missed the important lesson – that Ribena rots your teeth.
and your brain
sigh. The things we do ‘for science’ eh….
You are correct, Peta, that if the sensor had been cooled to liquid nitrogen temperatures or colder, then their calibration calculations would have applied better.
I guess I should point out that cooling this sensor to liquid nitrogen temperatures puts it far outside its specifications.
Well, there is an easier way to determine if it gets warmer due to more CO2:
https://www.dropbox.com/s/h7944heslj7gg7q/summary%20of%20climate%20change%20south%20africa.xlsx?dl=0
The answer, is well…. no. It did not get any warmer where I live over the past 40 years or so. In fact, minima dropped. However, if you bring in Berkeley, all of a sudden the trend is up instead of going down…
If co2 is such a great ghg why isn’t Mars warmer?
Don’t you know this universe is just a computer simulation? Ask he programmer.
Just a point I feel sure means I have missed something in my insistence on conformity to the basic laws of physics as contrasted with theories people make up and claim as a consensus with no proof ….. based on pre ordained and unproven belief in the cause of climate change and in conflict with the proven laws and basic methods of physics proven using deterministic methods.
This is about the assessment of the 4 Pi IR observed in the atmosphere, where downwelling equates to upwelling, but overtly ignores the fact such radiation is also created naturally by the gasses in the atmosphere under gravitational pressure:
This IR radiation is presented in the NASA heat balance as 300W/m^2 of scatter within the attroposprere and suggested whenever presented as caused by the “GHE Effect”. It self evidently cannot all be, because, even using LTE as above, the IR flux passing vertically through the box must be made up of:
A significant amount of the 4Pi IR flux has to be the result of the average temperature of the pressurised atmosphere that gives rise to the natural lapse rate, by PV = nRT, modified slightly for water vapour effect. Whatever the relatively small GHE effect is, a lot of the 4Pi IR comes from the characteristic temperature of the atmosphere under gravitational pressure heating. Thermodynamics 101.
Pressurised air will radiate equally in all directions. At around 1,000 cycles per cm at the surface, 10 microns in real units, LWIR. Nobody says. Why?
CONCLUSION: The 300W/m^2 of IR that is stated as observed (really?) in the NASA heat balance must be significantly due to the result of pressure alone. Rarely stated out loud. So here goes.
“Most of the so called greenhouse effect of Earth’s atmosphere is from the thermodynamic lapse rate, due to pressure.”
N&Z found their curve fitting model also suggested that pressure and solar orbit can substantively account for the lapse rate across the solar system, without other effect, where the planetary bodies had significant atmosphere. Their model had two variables so was far more reliable than over complex models that set out to assign the lapse rate observations to to chosen variables using presumption to include and exclude variables, and then force those chosen to match the observations,
The OPCC use far too many variables, often build models on models and unproroven ac sssumptios taken as proven. Not part of actual proven physics. No new laws have been proven by the IPCC, just assertion in their computer cloud of virtual reality, handed down to their priests by the nand of god, theirs when they programmed the cloud,.
So effectively without merit as any real modeller knows well (see Von Neuman, elephants and trunks). Probably wrong in modelling method, even wronger on extrapolation/prediction, because “No deterministic physics was used in the creation of these models”
N&Z made the mistake of being right but bumptious, no one I have read faults their model so they are hatefully right as regards what they did. BUT they also said GHE was not real instead of “small and insignificant” compared to everything else, as Judith Curry does with AGW versus the observed and normal in the proxy record cyclic global warming we are now at around the warmest point in the cycle of, probaly caused by the short term change of solar orbital forcings – NGW anyone?
As Douglas Adams observed regarding the lynching of the inventor of the infinite improbability drive when he announced it at a Galactic Physics Conference, nobody likes a smart arse. Being right makes things worse. As Giordano Bruno found out, So N&Z have been lucky, so far. Nobody expects the climate inquisition. Watch out for Wicker men….
But to return to my key point, the very basics of the presentation of the GHE to lay people……
Surely most pf NASA’s 300W/m^2 of 4Pi scattered IR is the natural consequence of an atmosphere under pressure, which will thus diminish in intensity with altitude in a linear way. Real GHE by IR scattering is only a small part of the 4Pi IR radiation, and hence has a small effect on the lapse rate from energy lost in the scattering, which effect on oceanic SST is easily controlled by the dominant natural negative feedback to SST change.
I then go onto what that feedback actually is, an effect that has stabilised atmospheric climate change from multiple causes, cyclic and exceptional, for at least 500Ma, by oceanic feedback to warming that cools the surface and creates cloud albedo, and vice versa, since there were oceans, hence no tipping points. But that’s another story.
PS Please no “Don’t call me Shirley” answers.
The minor little problem is that Nikolov’s pressure model violates conservation of energy.
A kinetic energy gradient in an isolated column of gas in a gravitational field, at rest, does not violate conservation of energy. Some people in this situation use the term “heating” which is probably misleading. It is not heating, it is a gravitationally induced distribution of kinetic and potential energy, resulting in a gradient.
Air at the bottom of a gravitational gradient would heat as it compressed, but the heat would radiate away.
Actually, it does violate conservation of energy. If your claim were true, we could use the temperature difference between the top and bottom of the column to power a heat engine, resulting in perpetual motion …
For a more detailed proof, see Dr. Robert Brown’s post “<a href=”https://wattsupwiththat.com/2012/01/24/refutation-of-stable-thermal-equilibrium-lapse-rates/” target=”_blank”><b><i>Refutation Of Stable Equilibrium Lapse Rates</a></b></i>“.
w.
Dr. Brown’s post has a lot of holes in it. He is trying to build a heat engine out of unobtainium, for one thing, and for another, he is assuming his conclusion. You can’t refute anything that way.
Tom is mistaking dynamic compression involving work for steady-state equilibrium, and you can’t prove anything that way either.
Tom Halla 10:36 am, pistons and cylinders do not inhabit the atmosphere. The dry lapse rate is just a line demarking hydrostatic balance which is often observed in Earth’s stable real atm.
Willis 11:05am, there is no perpetual motion in atm. or ocean heat engines.
You should want to discover the temperature difference in the atmosphere CAN be used to power a heat engine as has been shown by multiple sources writing on ocean thermal energy conversion. The heat engine in the atm. is not nearly as efficient as in the ocean; neither are reasonably economical. Both will run until universe entropy is maximized and then will stop running (i.e. stop producing entropy) so there is no perpetual motion.
Dr. Brown’s setup is a similar heat engine at the start producing entropy & will eventually stop at max. entropy at a certain T(z). Dr. Brown just assumes the column vertical temperature becomes constant in his starting assumptions list.
Nikolov & Zeller is crap that has been debunked here many times, not least by our esteemed polymath Willis Eschenbach.
There is NO heating of air without work. The obvious common sense proof of that would be a pressure cylinder containing oxygen that a person with emphysema might need to roll around with them to be able to breathe. How can it be sitting there at room temperature when by your theory it must be hot?
An air compressor tank is hot because the compressor does work on the air. If the compressed air is not used and doesn’t have any leaks in the air hoses, etc., the tank will cool off to ambient temperature, but still be pressurized. Another example of your mistaken thinking.
There are some very high pressure vessels which according to this stupidity should be untouchable … you can’t fix stupid and the promoters so ignore them.
Well, LdB I think that there’s a balance that needs to be struck between engaging commenters who seem to be sincere like Brian, but by my lights at least seem deluded, and trolls like griff and Izaak who should only be engaged for sport 🙂 and sparingly.
This site gets a lot of traffic and I’d hate to see that a newbie walks away because of the perception that bad science is promoted here and is not challenged. Another concern is that visitors without the benefit of an engineering education might join the ranks of those promoting nonsense.
This is a poor example, since the oxygen cylinder is affected by the outside. Or maybe you’ve never noticed the temperature difference between high and low elevation locales? Try going up to the top of an Hawaiian mountain and then tell us that pressure has no effect on the temperature of a planetary atmosphere.
Sigh. I put this out on a regular basis, it seems, and never remember to copy it into a txt file to just cut and paste.
Temperature is a measure of total kinetic energy in a volume. The total kinetic energy is a function of 1) the mass being measured and 2) the velocity of the particles that compose that mass.
Density is a measure of the mass contained within a volume.
From these two definitions, one can see that a volume of a very dense material with slow-moving particles, can have the same temperature as a very non-dense material – but with rapidly moving particles.
At the top of Mount Everest, the molecules are moving very rapidly indeed – faster than at sea level, as they receive more energy from the Sun than the molecules at lower altitudes. But the kicker is that the atmosphere is far less dense. The difference in density has much more effect on the temperature than the speed of the molecules.
Note that I absolutely hate the misuse of “temperature.” The correct definition is as I just gave (or the simpler alternative, “total heat content of a mass”). Yet, you see things like “the temperature in the thermosphere ranges between 200° C and 500° C.” Yet you would still freeze solid quite quickly if you suddenly found yourself at that height. (After you asphyxiated and took immense UV radiation damage, of course, so six and one, half a dozen and another…)
Edit: Hah! Remembered to copy this time. Now all I have to do is remember where I put it, and to go into “source code” mode when pasting it. (WordPress widget bars delenda est!)
Your definition of “temperature” is not correct. It is NOT “the total heat content of an object.”
Suppose we have two blocks of steel, a 1 kg block, and a 10 kg block. Now, the “specific heat” of a substance is how much energy (in joules, “J”) we have to add to 1 gram of a substance to warm it by one degree C. There’s a chart of the specific heat of some common substances here.
Now, the specific heat of steel is 0.466 joules per gram per degree C.
Let’s assume the two blocks of steel start at the same temperature. To raise the temperature of the 1 kg block by 1°C, we have to add 466 joules.
But to raise the temperature of the larger 10 kg block by 1°C, we have to add 4660 joules.
Now, they are still each at the same temperature of the other one, but one has 466 J more heat content, and the other has 4660 J more heat content. Obviously, the total heat content of the two blocks are different … but they are at the same temperature.
So no, the temperature is NOT “the total heat content of an object” as you claim. That is an incorrect understanding.
w.
I think he refered to heat content per area.
My comment above expresses a similar concept even more simply.
From my perspective, the obvious affect is heat capacity. More gas allows greater heat capacity.
Or more molecules vibrating per sq meter. And as those molecules are compressed further, the energy per sq M increases.
Willis has not debunked N&Z. With much respect to W.E. and his many accomplishments, his understanding of physics is not up to the task. This confused even Richard Feynman, as far as anyone can tell from his lecture, so it’s not as trivial as it looks.
Steve, Dr. Roy Spencer begs to disagree. See his post “Giving Credit to Willis Eschenbach for setting the Nikolov-Zeller silliness straight“. You’ll have to forgive me for taking his opinion over yours.
w.
You can take anyone’s opinion you like, Willis, but your grasp of physics fails you. You are relying on Dr. Brown’s hypothetical thought experiment, which has more holes in it than a Swiss cheese. I suspect this is because he is a professor, and professors can routinely get away with a lot of misconceptions that would never fly in the real world. You may be able to fool people who know less about physics than you do, but you can’t fool everyone.
The Stefan-Boltzmann equation has nothing to do with cavities. The original equation was for the emission of a black surface in a vacuum. It was later modified 1) by an inclusion of an emissivity factor. Then it was modified to include an emissivity factor for both the source and receiving surface with the same area to give an heat flow still in the vacuum. The S-B equation can only be used with surfaces and not gases (where different factors including path length and partial pressures of radiation absorbing gases and emissivity factors relative to their wavelength absorption must be considered.) With respect to Earth’s open system and the 2nd law of thermodynamics there are no “greenhouse” gases. However, Clouds do have a surface of liquid and solid ice which have an effect on incoming radiation from the sun and on the rate of heat loss form Earth’s surface. These effects are not easily calculated.
Yeah but what if I just pretend the volumetric body of gas is a 2D solid layer? /s
I would be surprised to be told that astrophysicists, interested in the temperature of the surface layers of the gas giants, Saturn and Jupiter, did not use the S-B equation to estimate the temperature, given the limited physical access to those bodies.
On the other hand I have always had some difficulty in the concept of em radiation, other than characteristic molecular spectra, being emitted by dilute gases, as in TOA calculations, when em emission or absorption, requires an oscillating dipole, or varations in electrical anharmonicity. Perhaps the top of the atmosphere is not as dilute as I, in my ignorance, imagine.
Energy leaves the surface of the earth by five primary heat transfer processes, non-radiative, i.e. conduction, convection (natural), advection (forced), latent (evaporation & condensation) and radiation.
These five heat transfer processes work together and in concert and radiation does not function independently from the others.
When the non-radiative processes increase, e.g. from mechanical fans (wind) or water sprays (storms) that in turn cools the system and reduces the amount of radiation.
Emissivity is the ratio between the total energy absorbed/emitted and that emitted by radiation alone.
If a contiguous media participating through non-radiative heat transfer processes cools the system emissivity must be less than 1.0 and not a black body.
Since the system cannot upwell energy as a radiative black body, there is no “extra” energy for the GHGs to absorb and emit, no GHG warming and no man-caused climate change.
BTW I have already demonstrated this by experiment not just once, but fiveth.
No Nick.
Radiation is a function of the fourth power of absolute temperature, independent of heat flow. Of course if other transport phenomena reduce the object’s temperature (as they must), that will reduce the amount of radiation.
What physical mechanism can you imagine that would allow a molecule to “know” that it should adjust its emission of radiation due to some other molecules in the vicinity moving away (convecting)?
Is it your view that the LED in your dentist’s office must be 6,000 C to emit 400 nanometer light?
No, but that’s electroluminescence which is from the devil’s lightning I believe. You may want to take that explanation with a grain of salt, though.
Nick,
I thought that conduction between a solid and a fluid (or a fluid and a fluid) can only occur if the fluid is static? I don’t think conduction is one of the ‘primary’ heat transfer processes in the earth-atmosphere system. Certainly not in the 70% of the earth’s surface that consists of a fluid-fluid interface, neither of which is static.
Speaking as the non-scientist in the room, if you have to look in a box for the greenhouse effect you have already failed. Just give up.
Of interest water vapour at 100°C shows no thermal image until it hits a solid:
https://youtu.be/6yTErdEg_OE
and the emissivity problem using a copper plate half painted
Most Thermal imaging cameras do not react to the emissions of CO2 molecules (if they did then looking through the atmosphere would be like looking into a fog!).
Pointing them into the sky will not measure back-radiation. Pointing them onto a cloud (liquid water=grey body radiation) will show the cloud temperature.
See info here Climate and Stuff: Sky Temperature and Thermal Imaging
Your detail is meaningless there are three modes of translational motion in a gas and a fourth in the quantum domain. You thermal camera detects only one motion … do you even know which one?
The microbolometer thermal imaging camera is effectively a series of very small plates which accepts a wide range of IR frequencies. It does not care which mode of which gas creates the IR if it is the passband of the WHOLE instrument then it adds energy to the microbolometers and they warm (note that they are never cooled by the image projected onto them!) causing a change in detected resistance, The pass band of thermal imaging cameras is partially set by the germanium lens – here is a radiation map. germanium lens response, and instrument response.
Flir+and+atmospher+passbands.jpg (1600×1055) (bp.blogspot.com)
Note that the major CO2 band is outside the cameras response.
The thermal camera does NOT, it cannot, no way detect the vibration of atoms other than if the emitted IR frequency is outside the response bandwidth of the camera.
The micro bolometers are simply tiny plates coated to absorb IR frequencies within a certain range
Also the number of vibrational modes is not always 3!
I understand that a tri-atomic linear molecule eg. CO2 has 3 vibrational modes and that translational displacement is represented with 3 Cartesian axes but I don’t visualize the 3 translational modes you speak of.
Here is an IR image of ice floating in water. I assume the ice is colder than the air surrounding it, but we see the ice but not the warmer air just like you say. CO2 emission is below most equipment. Even the FLIR page used to list cutoff at 15 micro.
Off in the distance, that “fog” is because H2O in the air has absorbed the IR from that distance. Plus the camera is using a filtered wavelength where water vapor absorption is intentionally low so that it does not fade out the pics.
You are making claims about what in the distance and filters which were not knowable. But it does not change what he said and the photo shows.
I operated FLIR (foreward looking infrared) equipment for years all over the North Atlantic and Mediterranean. This picture is what I would expect to see doing maritime ice searches.
We only had the ability to select white hot or black hot for our equipment.
One thing such experiment absolutely requires is opacity gradient, which wasn’t there. Greenhouse effect works by moving effective radiative height higher for CO2 part of the spectrum. And you just can’t simulate this in a small scale experiment.
Calorimetry is hard, because everything conducts heat, if slowly. I have built and operated calorimeters, and used commercial units. Here are a few observations:
And those fans need to be considered.
The energy to keep it all well-mixed – how large is that relative to the effect they are measuring?
All very good suggestions. Experimental work to be credible requires a lot of work in design and then execution.
I’ve tried doing experiments to show the effect of adding a cold metal plate a distance from a warm plate (iron greenhouse). problems as you said
room temperature variation over ~1hr
thermal insulation effect diminishes as the insulation layer gets thicker
Used standard packaging grade polystyrene with applied aluminium foil on outside – much too great thermal mass
The new ultralight peanut packing type would be better or perhaps using multilayers of metalized Mylar as per the JW telescope would be better
detector was in in a insulated chamber with 3 layers of “clingfilm” as thermal insulation but ir pass. the detector was a cone of 40micron copper painted black with a themocouple placed at apex and coupled to cone with thermal paste. Again much too much thermal mass unless experiment in thermal chamber maintained at +-0.2°C.
The whole experiment was in a cardboard box to prevent changes in external IR from getting involved.
Heat was applied from resistor array attached to an aluminium plate. Power supply variability on output voltage of a few % obviously made a difference to the supplied power so yet more problems.
Thermo-couples were used to measure temperatures of heated plate by embedding in the aluminium with thermal compound.
Of course the thermocouple leads conducted heat from/to the setup!
Results seemed to show what was expected. but I would place <b>little veracity on these results!</b>:
greenhouse+results2.jpg (1176×522) (bp.blogspot.com)
heatbox3.jpg (588×468) (bp.blogspot.com)
heatsensor1.jpg (588×361) (bp.blogspot.com)
Is there any experiment that does demonstrate CO2 warming by radiative heat trapping?
I’ve not seen it yet.
Einstein btw stated clearly that in radiative heating of a gas, absorption and emission frequencies were irrelevant, heating was predominantly Boltzmann-Maxwellian momentum transfer.
https://ptolemy2.wordpress.com/2020/02/16/albert-einstein-said-no-to-co2-radiative-warming-of-the-atmosphere/
Bingo, I have challenged the adherents on here to show how the Law of Conservation of Momentum is not violated by the back radiation hypothesis. IR emission from the surface equally warms and cools the IR active gases of the atmosphere, otherwise we need to rewrite physics from the ground up.
Stimulated emission from IR has been observed in the atmosphere.
https://www.sciencedirect.com/science/article/abs/pii/0020089193900286
There is no such thing as backscatter in the lower troposphere.
IR in the 15 micron band is converted to kinetic energy. There is NO emission of another IR photon from a CO2 molecule below the Stratosphere. because the rate of collision prevents the CO2 molecules there from emitting.
I know that there are plenty of people who believe that Einstein was wrong and there is no such thing as the Einstein A co-efficient. Einstein won a Nobel Prize in 1921 for describing the photoelectric effect and he was able to calculate the time to emission for a large number of substances. No one yet has shown him to be wrong.Time to emission is close to a billion times longer than tie to collision.
(Less than 4 % of CO2 molecules in the air are re-excited by collision. However that re-excited CO2 molecule loses its energy the same way as one that is excited by absorbing an IR photon in the lower troposphere.
When a CO2 molecule is excited in the Mesosphere it has enough separation from other atmospheric particles that the excited molecule can emit However then the excitation is caused by collisions, NOT IR absorption.
This means that that particular CO2 molecule has been excited by absorbing energy from the atmospheric particles.and that absorbing of energy has cooled the atmosphere.
In short. lower atmospheric capture of IR warms the atmosphere and in the mesosphere, excitation of a CO2 molecule by collision cools the atmosphere.
The lower troposphere is a QUENCHING atmosphere. It cannot allow a CO2 molecule to re-emit a second IR photon. The process by which energy is spread upwards to the mesosphere is by kinetic energy. The process by which upper atmospheric CO2 is excited is by collision. (for the most part)
Doubt it? Take a quick look at the TOA spectra which shows a huge hole in the amount of energy escaping the Earth. It shows the IR being absorbed.
Take a look at the downwelling energy at the site on the North slope of Alaska, and in Oklahoma. There is nothing to see. Sure there is some minor energy shown after a model has been pressed into use to cause a signal to appear. Use of this model is specious. The amount of claimed IR is nonsense. Previous direct measurements were unable to detect any such energy. This is on an instrument that was designed to be the most sensitive in use. They re detecting an artifact.
This makes sense to me.
The concept of a ‘cooler effective radiative layer’ is seldom described in detail but I assume that near-collisions are the cause of ephemeral molecular bond energy level changes that result in emission, and they are less frequent at lower temperature.
Yes Einstein said IIRC that heat transfer from photons to (gas) atoms is the same in nature as the heat transfer between neighboring gas atoms. Boltzmann-Maxwellian, not photoelectric (primarily).
Here is the Einstein 1917 paper btw:
http://web.ihep.su/dbserv/compas/src/einstein17/eng.pdf
Thanks!
Mechanical engineers have design lord-knows-how-many furnaces and other radiant enclosures containing IR active combustion products CO2 and H2O. SO, yes, any number of experiments have shown this.
This is work with a similar aim. Have a look if you understand German. https://youtu.be/9qfThLR5psw
https://youtu.be/uyatWldokc4
Kevin, thanks for a clear, well-written, and complete description of the issues and errors involved in their experiment.
Next, I was amused by a number of the comments. We know that the very poorly-named “greenhouse effect” is real because we can measure it directly from satellites.
For those who claim that the “greenhouse effect” violates the laws of thermodynamics, it does no such thing. Please see my posts “The Steel Greenhouse“, “People Living In Glass Planets“, and “The R. W. Wood Experiment.”
For people who think that the compressed nature of the atmosphere is responsible for the fact that the earth is much warmer than the moon, I recommend my post “A Matter Of Some Gravity“, along with Dr. Robert Brown’s post on the same subject, “Refutation Of Stable Thermal Equilibrium Lapse Rates“. Both of us proved, not asserted but proved, that such ongoing heating is not possible.
My best to all,
w.
Thanks, Willis. It is not easy to convince people of the error of some model that they have made consistent with their world view.
Willis, I agree that you and Dr. Brown *tried* to prove that gravitational distribution of kinetic energy is impossible, but both of you failed. Dr. Brown’s idea of “proof” was a refutation by way of thought experiment, which could work, except that his thought experiment was full of more holes than a Swiss cheese, and then you relied on that, which didn’t help your case.
You can’t measure the RGHE from satellites, you can only measure it from upward-facing IR sensors on the ground, at ground temperature. No one has been able to do that, because it doesn’t exist.
Stebbins et al pointed IR detectors upward and analysed which molecules were associated with downward shining IR at night.
It was predominantly N2. With several frequency bands from OH species.
CO2 didn’t get a mention.
https://orbi.uliege.be/handle/2268/72225
Hatter, it seems you missed the reason CO2 didn’t get a mention … because it was deliberately filtered out to focus on the N2 radiation. The abstract says “Measured with a photocell and filters …”
Next, this is NOT thermal radiation of the type associated with CO2, water vapor, or other GHGs. That’s longwave infrared.
The radiation in the study is shortwave infrared, just outside the visible light range, at 10,440 angstroms. It’s in the range of frequencies emitted by the sun, not by the atmosphere. And it is emitted, not from just any N2 molecule, but only from an “excited” N2 molecule.
Finally, this hot news is from 1944 …
w.
CO2 didn’t get a mention because he was looking at the IR wavelength band in which CO2 doesn’t emit, he says in the paper that the filter/detector system he used couldn’t pass radiation above 11,500 A.
Steve, first, making an uncited, unsupported claim that someone’s proof is “full of more holes than swiss cheese” is nothing but handwaving. This is a science site. QUOTE what you think are the holes in Dr. Brown’s proof, and tell us exactly why they are wrong, or go away. I don’t have time for your meaningless handwaving.
Second, I published my proof two weeks before Dr. Brown published his, so your claim that I “relied on” his proof is not just wrong. It is a demonstration that you don’t have a clue what you are talking about and don’t even bother to check easily verified facts. You just open your mouth and spout claims.
Finally, I have no idea why you think you cannot measure the radiative greenhouse effect from a satellite. We know the ground temperature, which tells us what the upwelling longwave radiation is. We measure the upwelling longwave above that ground point from a satellite. The difference between the two is what is absorbed by the atmosphere and radiated back to the ground.
And if you dispute that, then where do you think the missing radiation (upwelling from surface minus upwelling at satellite) is going? And don’t just give me more empty claims. Link to facts, reference observations, show us the satellite data, etc. Like I said above … your handwaving is meaningless.
w.
Willis,
I didn’t say that CO2 or water vapour in the air won’t absorb LWIR upwelling from the ground. They will, of course, and thermalise it (convert to kinetic energy). Eventually all of that gets radiated to colder molecules in space, including satellite detectors. None of it gets radiated back to the ground. That is physically impossible, since the ground is warmer than the air most of the time. All of the energy that arrives ends up leaving, so I don’t see any “missing” energy in this system. (No one would expect all of the energy arriving at a detector in space to be emitted directly from the ground in the first place.)
The problems in Dr. Brown’s “proof” (thought experiment) are many. As I pointed out earlier, some of them are the following:
1) He is attempting to make a heat engine out of unobtainium. He calls it “silver”, but his version of silver doesn’t behave like real silver, so it is actually unobtainium. He assumes that it can transport heat (kinetic energy) upward and downward in a gravitational field without converting any of it to potential energy. It can’t do that, any more than gas molecules can. Since he is attempting to use this mechanism to prove that a gas must also not be able to behave that way, he is assuming his conclusion, in addition to inventing fictional materials. That is circular reasoning.
2) If he could make a heat engine that operated on the kinetic energy difference in a column of gas in a gravitational field (and it is not obvious to me that the amount of energy he could extract from it would exceed the Planck minimum quantum of energy, since heat engines have efficiency limits, so it might actually do nothing at all), then all he would be able to do is cool down the gas in question until it liquified, or reached the efficiency limit, whichever happened first. After that he would have to design a different heat engine to extract energy from a kinetic energy gradient in a liquid, which would only be able to cool the liquid. There is only so much entropy available, and eventually he will run out. That is not a perpetual motion machine, so his “proof” fails on this score too.
From where I am sitting, it looks like you and Dr. Brown are the ones doing all the hand-waving.
Steve, I’m going to leave you to your unassailable ignorance. As the old saying goes, “You can lead a horse to water … but teaching him how to do the backstroke is a real bitch”. The number of your incorrect understandings of thermodynamics, as well as how tightly you hold on to them and how proud you are of them, means there is no point in continuing.
Best regards,
w.
Classy, Willis, classy. Ran out of argument and comprehension, so all you’ve got left is name-calling. Well, carry on then. I was hoping for better from you, but I shouldn’t have expected it, since we ran into a similar problem when we tried to explain quantum electromagnetic radiation to you. You can lead a horse to water, and all that…
Steve, I didn’t “run out of argument”. I’ve given you two separate proofs, not claims but proofs, that the atmosphere alone cannot provide energy on an ongoing basis to warm the surface. One is from Dr. Robert Brown, who teaches this stuff for a living. The other one is mine, and has been endorsed by Dr. Roy Spencer. Nobody has ever found an error in either one of them.
You seem to be incapable of understanding them, and your objections to them make no sense. For example, you claim that:
“He [Dr. Brown] assumes that [silver] can transport heat (kinetic energy) upward and downward in a gravitational field without converting any of it to potential energy.”
I know of no one but you making the claim that when heat is conducted vertically some of it must perforce be converted to potential energy. I see no physical reason why that would be true. You provide no support or evidence for this claim. It’s not mentioned in any of the many engineering texts that I’ve read.
Given that you hold those kinds of crazy ideas and present them as if they were well-known facts, I have no interest in further discussing these subjects with you.
I’m not “out of argument”. I’m out of patience. I can’t argue against your level of misunderstanding of thermodynamics.
Regards,
w.
Whether you want to argue or not is up to you, Willis. But there is no physical way to transfer kinetic energy (heat in solids is exhibited as kinetic energy of the molecules making up the solid) upward in a gravitational field without converting some of it to potential energy. That’s how gravity, potential energy, and kinetic energy work. Maybe you should measure the vertical and horizontal conductivity of heat in all directions in a metal, over a significant distance, and see if you get the same conductivity every way. This is not a crazy idea, it is basic physics. It applies to solids just as much as to gases, because every atom is subject to gravity, regardless of what type of material it belongs to. No one can escape gravity. You probably won’t see this in engineering texts because the effect is not big enough to matter in human-scale engineering contexts. It does start to matter when Dr. Brown imagines a several-kilometer-high bar of silver that can conduct heat effortlessly and losslessly all the way up and down, though. That’s not going to happen.
Sure, I could be wrong about that… I haven’t seen anyone else mention it either. But everything I know about physics tells me that it is an inescapable conclusion. If you don’t like the conclusion drawn by thinking about the vertical movement of vertically adjacent atoms in a solid in a gravitational field, which was how I was thinking about it, then consider that heated metals undergo thermal expansion, for the same kinetic energy reason I just described. (I think it’s the same effect, I just hadn’t considered that the potential energy conversion would result in expansion, but obviously it has to.) And that effect definitely shows up in the engineering texts, probably by around page 3. Now where do you think the energy required to perform vertical thermal expansion (increase of potential energy) comes from? There’s no free lunch…
If it were, somehow, mysteriously possible to transmit heat/kinetic energy upwards in a gravitational field without converting any of it to potential energy (say what?) then the fictional heat engine might have enough temperature differential to produce work, but that would just cool down the entire isolated air reservoir. Nothing is heating it, after all. So Dr. Brown can’t escape the inevitable decline of entropy that results. His heat engine will eventually sputter and die.
So Dr. Brown’s “proof” is not a proof. It is a thought experiment built on several false assumptions. I don’t remember what makes your “proof” different from his, because the last time I looked you relied on his thought experiment to make your case.
Remember that I am not claiming that the “atmosphere provides energy on an ongoing basis to warm the surface”. That by itself would certainly violate the conservation of energy. Instead, what is going on is that gravity sorts moving molecules according to their potential and kinetic energies. Temperature only measures one of these, hence giving you a “misleading” picture of total energy, which is of course flat and invariant when everything is at equilibrium.
If you want to try to correct your apparently faulty intuition about this, try a couple of simple thought experiments (much simpler and easier to prove to be correct than Dr. Brown’s):
1) What does the potential and kinetic energy gradient of an isolated column of gas consisting of one gas molecule look like? Then add another molecule…
2) What is the *potential* energy gradient of a normal column of isolated gas in a gravitational field?
Good luck! Previous people who have tried to answer these questions from a “radiationists'” point of view have painted themselves into some pretty funny corners. But I’m sure you can do better.
“I didn’t say that CO2 or water vapour in the air won’t absorb LWIR upwelling from the ground. They will, of course, and thermalise it (convert to kinetic energy). Eventually all of that gets radiated to colder molecules in space, including satellite detectors. None of it gets radiated back to the ground. That is physically impossible, since the ground is warmer than the air most of the time. “
Any gas molecule in the upper atmosphere which is excited for sufficient time to emit is capable of emitting in all directions, the temperature of its target is irrelevant. On average a collection of such molecules will emit slightly less than 50% towards the surface. If the wavelength emitted is in a region of the atmospheric absorption spectrum which is transparent the photon will reach the surface and be absorbed regardless of the respective temperatures.
Phil, that is an incorrect understanding of quantum electromagnetic radiation. Excited atoms can only transfer quanta of energy to less-excited (colder) atoms of compatible wavelengths. Not every atom in a colder region is unexcited, and not every atom in a warmer region is excited; but that is the general rule. There is no measurable radiation from a colder region to a warmer one. Only occasional quantum exceptions.
What I find interesting is that it takes the same amount of energy to raise the temperature of liquid water 1C, regardless of temperature. This is the basis for the calorie.
But the GHG theory assumes that it rakes more energy to heat warm water 1C than it takes to warn cold water 1C, due to the 4th power SB law.
Ferd, the SB law relates how much energy a body is losing via radiation to its temperature T.
It says nothing about the amount of energy needed to raise water by 1°C. It just says that the warmer it gets, the faster it radiates energy, which is a totally different question.
w.
@ Kevin Kilty, this may need correction:
“The blackened aluminum radiator has an emissivity close to 1.0. It is perhaps 0.96, but the bare styrofoam is far from black at IR wavelengths. An accepted estimate of emissivity of this material is 0.60; i.e. at any temperature it will radiate only 60% as strongly as the Stefan-Boltzmann law predicts.”
From the study:
“The temperature of the rear Styrofoam wall was measured with a thermocouple, painted black (in order to absorb IR radiation).” Emphasis mine.
The black paint would change the emmissivity of the styrofoam back panel, and wouldn’t be 0.60 as used in the calculations. Maybe not the 0.96 of the blackened aluminum, but close?
I took this to mean that they painted the thermocouple black, not the styrofoam panel.
Fair enough. Thank you.
There appears to be serious deficiencies in this paper. Look at Eq. 3 for the
absorption of IR in a tube of length x.
𝐴=0.0188×ln(𝑥)+0.1228
Clearly this equation isn’t correct because for x=0 the absorption is negative infinity
and the absorption remains negative for small values of the length. Plus there are
no units given for the absorption.
And looking at many of their graphs it appears clear that they stopped their experiments
before the system had reached thermal equilibrium and thus none of their conclusions
or their analyses are valid.
In all fairness Kevin, please analyze Bill Nye’s and Al Gore’s experiment that indicated co2 is a GHG.
I would not want anyone to think you were anything but objective. You are objective aren’t you?
Bill Nye’s and Al Gore’s experiment is a complete nonsense. Why would Kevin (or anyone else) waist his time to analyze it.
To provide the expert analysis indicating it is complete nonsense and to prove Kevin is objective.
I took a day and had three successive physics laboratory sections do the Nye/Gore experiment just as they stated it, and we got “Nye” results. You can find my discussion of this on a very far back page on WUWT if you look for it. NOAA yanked the “experiment” from their website soon afterward.
A typical setup for gas cell IR transmission measurements is a spectrometer > air curtain > chamber 1 (T, Pressure, and mixing fans) > Air curtain > chamber 2 (T, Pressure, and mixing fans) > Air curtain > T controlled blackbody.
Why introduce the potential error from the film? What is the transmission spectrum of the film – does it matter to the sensor region of interest, does it change with temperature?
I would also recommend equalizing pressure with a carrier gas vs a vent. Typically, I was measuring “bad things” in those chambers so I might be biased.
And, yes the sensor fov must be carefully measured to avoid clipping.
Can’t do a thorough energy balance without knowing something about the film’s IR properties. Also note, please, that this thermopile sensor (also known as a bolometer), is not a spectrometer and can’t be analyzed or its measurements interpreted as if it were. This is part of the authors’ misuse of SB.
There is no mutual exchange of radiation between a spectrometer and what it views, but there is such with a bolometer.
Thanks for pointing out all the technical short comings of this experiment…..But even if we could correct all the errors, wouldn’t this apparatus really just be measuring the differences in the heat capacity of a co2 atm vs air and not “GHE” ( a delay in energy transfer from source to sink) ?
Actually the difference in heat capacity of CO2 versus air, which amounts to about 15% is all, does produce a delay over the 15% change in time constant involved.
It’s a convection oven.
At least it’s not a computer model.
Gas can never be considered a “black body” and “emmissivity” can not be used except as a way to size furnaces, i.e. a fudge empirical formula that’s “good enough”. That is because gas emits in bands. Outside the band, emmissivity is zero.
The “missing” energy is used to raise the CO2 to a steady state temperature. I suspect one problem is the failure to distinguish “steady state” with “equilibrium”. Next, the CO2 at 33C is not emitting much radiation. Do the authors understand “heat capacity”? The CO2 absorbs energy until it reaches 33C. At that temperature I’m assuming the system is at steady state and the CO2 is emmitting a miniscule amount of energy in its narrow radiation band.
One thing, at some point the total energy exiting the front window had better return to the previous value, or they have a major problem, or they didn’t wait long enough.
From reading the paper, they didn’t wait long enough for the system to reach steady state. The CO2 temp and “backscatter” were still climbing at the end of both curves. The “missing heat” is likely convective loss being absorbed into the foam. Once that is basically “done” with delta T dropping, the CO2 will warm a little more and the radiation through the window will come reasonably close to the air case.
The lack of temperature rise in the front chamber was likely due to reflection by the white foam.
Kevin,
Thank you for this. It is a valuable contribution. However, I do not think it explains the main mystery of the experimental results, which IMHO is not the absence of heating effect of back-radiation. Some 76% of the area of the back panel is uncoated extruded polystyrene, which has an absorption profile which displays only a small overlap with the emission bands of CO2.
The more puzzling question is why the temperature evolution in the front chamber is the same for all three gases tested – air, argon and CO2. I am at a complete loss to explain these results. Calibration error in the IR measurements for evident reasons cannot explain the temperature measurements which were taken independently.
The experimental design dictates that the front chamber contains the same number of moles of each of the tested gases at the start of the experiment (Avogadro rules OK). During heating, at a given achieved temperature, each of the gases should have lost a certain number of moles to the outside to maintain a constant pressure balance with the external room pressure. The universal gas law (we can neglect the small effect of the gas deviation factor) says that since the volume and pressure are fixed, then for the same achieved temperature each of the gases must therefore lose an identical number of moles to get to that temperature. Each of the three gases loses exactly the same fraction of its initial mass to gain this temperature. In other words, in each of the experiments the number of moles retained inside the system is the same for each tested gas once that gas achieves the same given temperature. It is a short step from there to deduce from specific heat measurements that to get to the same achieved temperature, the amount of retained/accumulated heat in the front chamber for CO2 should be about 128% of that required for air, and that argon should require only about 73% of the retained heat required for air. These ratios are preserved for comparison at a given temperature even after accounting for mass losses.
The (unknown) input power–time profile from the halogen lamp should be very similar for all three cases. For the same achieved temperature, we can also safely say that the flux losses via the insulation and conductive losses via the front plate should be very similar between the cases. The differences in retained energy in the front chamber between the three cases should then be mostly explained by
(a) The differences in heating requirements of the three gases after accounting for the difference in mass losses
(b) The differences in radiative losses via the front plate
(c) Any differences in net radiative losses from front chamber to rear chamber due to back radiation
What is actually observed in the experiments, however, are temperature profiles which are almost identical in both chambers for all three gases. There is obviously at least one compensatory mechanism in IR absorption and emission. A direct comparison of the CO2 case with the argon case suggests that the CO2 needs to retain about 76% more heat than the argon in order to match its temperature profile. The argon is almost transparent to IR transmitted from the source plus the IR from the air in the rear chamber, and hence relies largely on conductive and convective heating from the plate dividing the rear and front chamber. The CO2, on the other hand, is able to convert some of the IR to heat. However, I cannot find any analytic reason why the CO2 should retain exactly the correct amount of heat to match the temperature profile of the argon. Various explanations which I have tested based on a coincidence of optical properties and path length all fail since the case run with air in the front chamber also matches the argon temperature profile. If anyone can find a credible explanation for this extraordinary coincidence of temperature profiles, I would be very grateful to hear it.
What is missing from the discussions here are the comments by Seim and Olsen. In fact, why even discuss the paper, whilst not inviting them to react. I also have a few questions for them.
I would expect that if a GH effect existed, one must be able to find it, where ever you measure. Empirical. However, I found that at the south pole and here, where I live, there has been no increase in temperature over the past 40 years.
See my recent blog post, here: (click on my name)