From the department of “I told you so and I have an experiment that precedes this to prove it” comes a paper that proves Bill Nye’s faked ‘greenhouse effect’ experiment is also based on the wrong ‘basic physics’. Remember when I ripped Bill and Al a new one, exposing not only their video fakery, but the fact that experiment fails and could never work? Well, somebody wrote a paper on it and took these two clowns to task.
The Hockey Schtick writes:
Oh dear, the incompetent & faked attempt by Bill Nye to demonstrate the greenhouse effect for Al Gore’s Climate “Reality” Project has also been shown by a peer-reviewed paper to be based upon the wrong “basic physics” as well. According to the authors, Nye’s experiment and other similar classroom demonstrations allegedly of the greenhouse effect:
“All involve comparing the temperature rise in a container filled with air with that of the same or a similar container filled with carbon dioxide when exposed to radiation from the Sun or a heat lamp. Typically, a larger temperature rise is observed with carbon dioxide and the difference is attributed, explicitly or implicitly, to the physical phenomena responsible for the climate change. We argue here that great care is required in interpreting these demonstrations and, in particular, that for the case of the demonstration described by Lueddecke et al., the results arise primarily from processes related to convective heat transport that plays no role in climate change.”
Bill Nye the propaganda guy experiment for the Climate Un-Reality Project
According to the paper, Nye’s experiment
“demonstrates an entirely different phenomenon: The greater density of carbon dioxide compared to air reduces heat transfer by suppressing convective mixing with the ambient air. Other related experiments are subject to similar concerns. Argon, which has a density close to that of carbon dioxide but no infrared absorption, provides a valuable experimental control for separating radiative from convective effects.“
Not only did the authors find that addition of the non-greenhouse gas Argon had similar heating effects to CO2, the Argon control actually heated up slightly more than in the greenhouse gas CO2 experiment, definitively proving that such experiments assume the wrong “basic physics” of radiation were responsible for the heating observed, instead of the limitation of convection due to CO2 having a greater density compared to air.
Nye’s experiment not only limits convection by addition of denser CO2, it completely eliminates convection by enclosing the CO2 in a bottle with the top on.
According to the authors,
“It has been known for more than a century that the warming of air in a real greenhouse results primarily from entirely different physics—mainly that the glass prevents mixing between the warm air inside and the cooler air outside, and therefore suppresses convective heat transfer between the interior and the exterior; the infrared absorption of the glass plays a much smaller role. We show here, via experimental data and a simple theoretical model, that the effects observed in the demonstration described in Ref. 1 arise from a similar restriction of convection rather than from radiative effects. In this case, it is the density difference between carbon dioxide and air, rather than the presence of a solid barrier, that suppresses mixing of the gases. Although the details differ, similar considerations apply to other demonstrations that have been reported.”[including Nye’s ‘greenhouse effect’ enclosed in a glass bottle]
Thus, Nye’s experiment, in addition to the video fakery and incompetence, is not even wrong on the “basic physics” of the greenhouse effect.
As the authors point out in the conclusion,
“Although not an accurate demonstration of the physics of climate change, the experiment we have considered and related ones are valuable examples of the dangers of unintentional bias in science, the value of at least a rough quantitative prediction of the expected effect, the importance of considering alternative explanations, and the need for carefully designed experimental controls.”
The paper in the American Journal of Physics:
Climate change in a shoebox: Right result, wrong physics
Paul Wagoner , Chunhua Liu and R. G. Tobin
Classroom experiments that purport to demonstrate the role of carbon dioxide’s far-infrared absorption in global climate change are more subtle than is commonly appreciated. We show, using both experimental results and theoretical analysis, that one such experiment demonstrates an entirely different phenomenon: The greater density of carbon dioxide compared to air reduces heat transfer by suppressing convective mixing with the ambient air. Other related experiments are subject to similar concerns. Argon, which has a density close to that of carbon dioxide but no infrared absorption, provides a valuable experimental control for separating radiative from convective effects. A simple analytical model for estimating the magnitude of the radiative greenhouse effect is presented, and the effect is shown to be very small for most tabletop experiments.
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Nick Stokes,
You keep saying that Arrhenius actually measured CO2s IR effect. To my knowledge he did not. He calculated it using Stefan-boltzman. Actually measuring CO2s IR in a laboratory experiment is even difficult today with highly accurate instrumentation.
“””””…..Duster says:
August 11, 2014 at 11:49 am
george e. smith says:
August 10, 2014 at 10:30 pm
Well this expose is also gobbledegook.
No, it is not. The work is not about “climate” or determining anything remotely related to climate……”””””
Well Duster; just where in MY post did YOU read anything about climate ; because I never mentioned anything to do with climate.
And where in THEIR ESSAY did YOU read anything that they said about Bill Nye’s experiment using totally phony, and illegitimate EM radiation sources, that don’t in your wildest imagination, approximate the actual earth radiation source, that is alleged to cause all this atmospheric heating.
I’m not disputing anything that happens in the atmosphere. Just what happens in Nye’s experiment, that is the true cause of his error. And THEIR explanation, has nothing to do with the real error, which clearly THEY don’t understand either; and evidently neither do you..
Running over a Brazil nut with an Abrams tank, is not a good way to demonstrate that you can peel one with your teeth; at least use something approximating your teeth; like a nutcracker, or tongs.
JJB MKI says: August 11, 2014 at 5:00 am
“Just out of interest, what do you think was the purpose of the Gore / Nye experiment?”
I said earlier that I think these demonstrations are of limited value, in that scale (km) and lapse rate are a vital part, and can’t be done in a bottle.
But they do put some things in proportion. Joe Bastardi above says that we have only gone from about 3 in 10000 to 4 in 10000. Another way to put that is that the amount of CO2 that IR has to get through to escape Earth is equivalent to about 2.8 m of 100% CO2 at surface pressure. It used to be 2 m. So showing that, on that scale, even a few cm of CO2 interact significantly with IR can help.
Tom T says: August 11, 2014 at 12:49 pm
“You keep saying that Arrhenius actually measured CO2s IR effect.”
Where? I said Tyndall measured absorptivity.
“””””…..DirkH says:
August 11, 2014 at 12:00 am
george e. smith says:
August 10, 2014 at 10:30 pm…..”””””
Well good for you Dirk. I predict a null experiment; whatever that is.
The water will be good, even when it is not frigged.
g
So, does anybody have a copy of this paywalled paper?
‘Climate change in a shoebox’: a critical review
M Bertò, C Della Volpe, and L M Gratton
M Bertò et al 2014 Eur. J. Phys. 35 025016. doi:10.1088/0143-0807/35/2/025016
Thanks…
Or, you could go out into the middle of a very dry desert close to the equator, and measure the rate at which a thin slab of e.g. copper that is painted as perfectly black (emissivity 1) as possible on top and insulated by a vacuum and perfectly reflective shield on the sides and the bottom, held at the bottom of a convective trap but fully exposed to the night sky cools, on average, correcting for the ambient temperature of the air in the convective trap, every clear night that the humidity remains below (say) 10% in a few hundred different locations, for ten years.
That would suffice to demonstrate two things. First, that atmospheric CO_2 isn’t enough to stop the copper from cooling to the freezing point most nights from any reasonable starting temperature — well-mixed CO_2 may slow radiative transfer of heat, but it doesn’t slow it by much as long as the ground layer is sufficiently conductive that the heat continues to radiate away in the unblocked wavelengths. Second, over a decade, atmospheric CO_2 will increase by at least 10 to 20 ppm. Over a decade, one would accumulate tens of thousands of samples of radiative cooling rates, with hundreds or even thousands available for any given set of initial and final conditions and deciles of CO_2 concentration in the range. One could, under those circumstances, make a stab at directly measuring the effect of additional CO_2 on cooling rates and controlling for confounding heat flow in the other available channels.
Indeed, it’s a shame that they didn’t start an experiment like this a decade ago, because if they had much of the discussion would be moot. The direct experimental observation of the marginal modification of the total radiative resistance in an environment where CO_2 is the dominant/only source of radiation absorptivity in the LWIR band would be enormously valuable, as now it is basically an unknown set from one of several approximate models with some user-controllable parameters that cannot really be directly verified, at least according to A First Course in Atmospheric Radiation, which is why its influence is usually given (as it is above) by a rather wide range, and without any sort of additional nonlinear modulation or feedbacks from the other GHGs, even ones that overlap their absorption bands where one is CERTAIN that the “bare” logarithmic dependence of both in Beer-Lambert is strongly suppressed (because saturated is saturated).
rgb
Nick Stokes is absolutely right to point out that the paper preceded the false experiment, because Hockey Schtick’s writeup takes the tack that the paper was in response to that experiment and had messages for Gore & Nye — when it clearly did not. Good for Nick (this time).
Nick Stokes,
Six of one half a dozen of the other. I’m saying that Arrhenius did not make any such measurement of what ever you want to call it. Such a measurement is difficult even today with the most advanced instrumentation.
Arrhenius made a calculation using stefan-boltzman. There was no experiment to my knowledge.
OK, now you are saying things that are just plain wrong once again. If you look up e.g. the single layer model in Grant Petty’s book — I recall somewhere in chapter 6 — and consider the fact that 2 meters of 100% CO_2 at surface pressure is 100% opaque to LWIR in its absorption bands, 2.8 meters is still — yes, 100% opaque to LWIR. The mean free path at the current concentration is order of a few meters. At 100%, it would be a few millimeters. The marginal change in surface warming would be zero. And this is just in a single layer model with no lapse rate, as I very much doubt that you could sustain a lapse rate across 3 meters sufficient to get the differential cooling that is supposedly important in the actual atmospheric radiative effect (a better name than greenhouse effect). The CO_2 would still be at basically the same temperature as the surface where it radiates through the presumably transparent atmosphere above — a layer of CO_2 on the ground like this would probably COOL the planet substantially relative to a well-mixed atmosphere because of the lack of a lapse rate at the scale height where the atmosphere becomes transparent.
If all you are trying to say is that CO_2 is a strong absorber of LWIR in its absorption band, this doesn’t really need to be “shown”, but sure, if anybody is in doubt there is plenty of spectroscopy that says otherwise, including multiple figures in Petty’s book. I don’t know what knowing this “helps”, though. The nuts don’t even understand the single layer model, the non-nuts understand that the atmospheric radiative effect is complex, not simple, and perhaps isn’t even fully understood (in at least the sense that we cannot precisely compute it even when we try very hard and with the best of intentions and tools).
Otherwise, putting a mirror on top of a heated house to reflect heat back down that is twice as thick isn’t going to make much of a change in temperature, is it? The point is that it is already a mirror. The lapse rate is an essential component of the expected variation of the atmospheric radiative effect with marginal variation of well-mixed CO_2 concentration, which is one place things get very complicated as the lapse rate is maintained by a mix of tropospheric convection, radiation, and the radiative and convective properties of the stratosphere and it isn’t clear that varying CO_2 concentration in atmosphere that is already many, many mean free paths thick without varying the temperature at the height where it becomes approximately transparent (in in-band LWIR) will have any effect at all.
Or did I completely misunderstand your point?
rgb
Looking over “On the Influence of Carbonic Acid
in the Air upon the Temperature of
the Ground ”
I’m actually quite sure that Nick Stokes is wrong. Arrhenius explicitly states that he cannot perform such an experiment as it was then presently impossible for him conduct.
??? It was my understanding that he actually has a degree or two in physics and a fairly extensive list of publications. He may also be a computer geek but then — so am I. So are a lot of people. We sometimes call them “computational physicists”, but in truth, if you are a theorist you sooner or later need to do a computation and most computations these days cannot be done analytically so many, but not all, theorists get to be pretty good programmers.
I do wish that people would stop banging on Nick (and for that matter Mosher) ad hominem. He is unfailingly civil — even more so than Lief, who long since lost his patience if not his temper with complete idiocy — and is rather knowledgeable about the topics of discussion and AFAICT generally competent in physics. I don’t always agree with him, but so what? I’ve been wrong (and he’s corrected me) several times in the past that I can recall, and perhaps I may have corrected him once or twice, perhaps not.
This is a hard subject; it’s difficult to be right all of the time no matter how smart or well-educated you are, and one’s perception depends on lots of things — trust in other people’s work, knowledge of statistics, knowledge of large scale modeling in general, knowledge of fluid dynamics in particular, and because it isn’t really computable (in MY opinion) a lot of the discussion ends up being about not the actual microscopic dynamics but about various linearizations and simplifications that are actually arguable as they aren’t “laws of physics” and that may or may not actually hold.
So please, let’s maintain a tiny bit of respect. If you have a specific place where you think Nick says something that is not true or that is arguable, by all means say so and advance your counterargument. Logical fallacies such as ad hominem won’t improve your argument, however, they just (in MY opinion) indicate its probable weakness. The more you have to say about your opponent, the less you have to say about the matter at hand, or what your opponent says.
rgb
rgbatduke: ” held at the bottom of a convective trap”
Could you explain that a little better? What, exactly is a convective trap? Since, apparently, you can provide a vacuum, why allow the slab to conduct heat to the the air in the convective trap? (I’m envisioning the trap as a box made of IR-transparent walls and containing air as well as the slab. I’m probably wrong.)
rgbatduke says: August 11, 2014 at 2:19 pm
“OK, now you are saying things that are just plain wrong once again. If you look up e.g. the single layer model in Grant Petty’s book — I recall somewhere in chapter 6 — and consider the fact that 2 meters of 100% CO_2 at surface pressure is 100% opaque to LWIR in its absorption bands, 2.8 meters is still — yes, 100% opaque to LWIR.”
Joe Bastardi said 1 molecule in 10000 couldn’t have an effect. I said it might be useful to have an experiment showing that on a cm scale, 100% CO2 would have a significant effect. You’re saying it blocks completely. Well, that’s a significant effect.
The argument about saturation goes back to Arrhenius vs Knut Ångström. It was eventually resolved with better measurement (Plass etc, 1950s) in Arrhenius’ favor. But yes, you can’t demonstrate all that with an IR lamp.
ps thanks
Finally, for those resurrecting the old FourierArrhenius/Tyndall arguments against CO_2 in the GHE, please — can we confine our discussion to the 20th century and to 20th century physics? At this point there is no argument whatsoever about the spectroscopy of CO_2:
http://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Type=IR-SPEC&Index=1#IR-SPEC
The quantum mechanics of CO_2’s electronic structure and its rotational-vibrational structure is reasonably well-understood, well measured, and reduced to spectrographic photographs at this point. It can be at least approximately computed with various tools, and while the computations are indeed approximate, they are certainly qualitatively correct in addition to being within spitting distance of quantitative measurements.
There is similarly basically no doubt about the correctness of the Beer–Lambert–Bouguer law that describes absorption and attenuation of radiation by a suitably coupled medium, or the theory of spectral lines:
http://en.wikipedia.org/wiki/Spectral_line
and so on. There is quite literally no doubt about any of this stuff in general, although if you go get yourself a physics Ph.D. and spend a few years doing atomic or molecular spectroscopy you might qualify yourself to argue about specifics in some particular circumstance.
The modern understanding of the GHE is a bit more involved than the 19th century, pre-quantum-theory explanations and arguments, so you are beating a very dead horse (or straw man, or red herring, or one of those things) if you resurrect them to beat on them some more. A good starting point would be Grant Petty’s book, A First Course in Atmospheric Radiation, which you can probably appreciate if you have at least a minor in University level physics, ideally one that includes a course each in E&M and Quantum mechanics (and it wouldn’t hurt if a third one were in thermodynamics). A bachelor’s degree in physics would be even better.
In the meantime, arguing about the hand waving arguments from the 19th century measurements and theories with more argumentative hand waving is basically waving bye-bye to the process of scientific reason. First, get to where you understand the single layer model in Petty’s chapter 6. It isn’t at all precise or realistic, but it is sufficient for you to understand that interpolating any sort of absorptive layer between an open system — an externally heated object and the cold bath into which the heat eventually flows — will increase the dynamic equilibrium temperature of the heated object. That alone eliminates all of the handwaving, and allows you to start concentrating on actual numbers and models knowing that the misnamed “greenhouse effect” is real, is responsible for the Earth being (on average) warmer than it would be without an atmosphere or with an IR-transparent atmosphere, and that in the specific case of the 70% ocean-covered Earth with its complex atmosphere, tilted axis, eccentric orbit, and so on it is not simple, certainly not as simple as any linearization at the level of a single layer model, possibly not computable even with multiple layers and the smallest cells we can afford to cover the Earth with these days.
That leaves lots of room to argue, but not about the existence of the effect itself, and most definitely not about whether or not a “trace gas” can produce a substantial shift in probable equilibrium temperature or play a key role in the Earth’s climate system.
rgb
To save money, I was thinking more along the lines of putting the slab in the middle of a grid of shallow (but increasing height) walls designed to inhibit the flow of air over the surrounding terrain and break up convective rolls of a larger size than the object. Shallow to avoid occluding the sky. But sure, one could also put a vaccum directly over the slab, covered with a window that was perfectly IR-transparent — if one could come up with a window that was perfectly IR-transparent. A vacuum would eliminate conduction as well, and I’m all for that. Basically, the idea is to make the object an insulated “blackbody” that can only lose heat via radiation, in only one direction, to the extent possible, so that one can eventually resolve the modulation of radiation losses in that direction due to CO_2 concentration increases. One could probably even manage this in a lab setting.
That is, one could (I expect) actually build a lab-scale experiment that would permit the warming of a heated object, or the slowing of the cooling of a passive object (relative to a provided, fixed temperature perfect absorber “bath”) due to an interpolated layer with a variable CO_2 concentration to be observed. What I don’t understand, given all the money that’s been thrown into making crap demos like Nye’s (and other crap demos I’ve seen online), is why nobody does this right. Give me a couple of hundred thousand dollars for materials, salary, and lab monkeys (I mean “graduate students”) to do the work of setting it up and hell, I’ll do it even though I’m a theorist, not an experimentalist.
Demonstrating Willis’s “steel greenhouse” model, or equivalently the single layer model with a fully absorptive intermediate layer, would actually be easy and reasonably cheap. Demonstrating the warming due to a partially absorptive intermediate CO_2 would actually be much more difficult (you’d have to work with both vacuum and an intermediate gas layer, and would really need the IR-transparent window capable of withstanding vacuum against an atmosphere and access to very cold temperatures e.g. liquid helium to simulate 3 K “outer space” as the cold reservoir, although one might be able to use Nick’s scaling argument above and somewhat warmer cold bath temperatures to get a lab result that “in principle” might scale to get within an order of magnitude of the right result for the actual atmosphere. The hard part there is getting the shunt resistances — the processes like convection and conduction and latent heat transport that won’t easily fit into a single layer lab experiment — even close to right.
rgb
On a loosely-related note, Bill Nye graces the cover of the latest Popular Science magazine with the caption “Bill Nye Will Save Science in America – or Go Down Swinging”….
The article centers mostly around his fight against creationists (and his debate with Ken Ham at the Creation Museum), but the editor couldn’t help but toss in a couple “climate change” morsels. E.g.:
“A similar poll found that one in two Americans don’t believe that humans are causing climate change, despite the fact that about 98 percent of all scientists do (a greater consensus than supports the link between cigarette smoking and lung cancer).”
“and a concerted effort to deny the scientific validity of human-caused climate change.”
Ugh
rgbatduke: “I do wish that people would stop banging on Nick (and for that matter Mosher)”
I heartily second Dr. Brown’s comment. My sell-by date is too imminent for me to waste time on Mr. Stokes’ irrelevancies or Mr. Mosher’s inscrutabilities, and it’s annoying to see them ramify through others’ responses.
rgbatduke: “I was thinking more along the lines of putting the slab in the middle of a grid of shallow (but increasing height) walls designed to inhibit the flow of air over the surrounding terrain and break up convective rolls of a larger size than the object.”
Thanks. I don’t have the background to judge whether the no-feedback figures universally almost universally relied on really should be, but I’m not at all sure that actual experimental results would not be at least a little surprising.
Nick Stokes,
I stand corrected. Computer modeler who has studied other topics, granted. My hero RGB says I should quit banging, so I shall. Would you care to assess my comments concerning the validity of Nye’s procedure? If so, why did you not already do this?
Michael Moon says: August 11, 2014 at 4:31 pm
“Computer modeler who has studied other topics, granted. My hero RGB says I should quit banging, so I shall. Would you care to assess my comments concerning the validity of Nye’s procedure?”
Perhaps you’d like to tell us about your scientific qualifications?
In the interest of respect for Nick… If we fo to the Sea Ice page and scroll way down to the “Source Guide”, we see a reference to “Nike Stokes”. I assume that’s Nick. If anyone is touching up that page anyway, might want to fix that while you’re there…
Bill is already educating my students. I show the Storm/El Nino video every year to demonstrate how wrong a person can be when discussing ENSO processes. First I teach them basic geophysics of Earth’s rotation mechanics, show how we on the Earth view the trade winds as blowing from East to West relative to the Earth (ground Earth spins fast, air Earth lags), and then I show the video segment. Those that catch the error get an A.
When viewed from God’s chair, yeh things are a bit different. But what matters is what we experience on Earth in terms of trade wind East to West weather and climate effects.
RGB wrote;
“Basically, the idea is to make the object an insulated “blackbody” that can only lose heat via radiation, in only one direction, to the extent possible, so that one can eventually resolve the modulation of radiation losses in that direction due to CO_2 concentration increases. One could probably even manage this in a lab setting.”
You may want to read up a bit about how the James Webb Space Telescope will be tested before it is launched. It took very expensive modifications to an existing vacuum chamber at Johnson Space Flight Center (Houston, second largest vacuum chamber in the USA). This chamber was originally designed to test the Apollo capsules and is listed as a “National Civil Engineering Landmark” (I may have the exact designation slightly incorrect, sorry).
In summary, it was necessary to build a large liquid He shroud INSIDE a large liquid N2 shroud to get the payload down to the necessary temperatures. Pumping the chamber down to “hard vacuum” levels is the easy part, establishing the “3K background temperature” is quite expensive, figure on about a million dollars a day for the He and the N2 and the energy to run the pumps, etc.
Maybe you can talk them into “injecting” a whee little bit of CO2 to test the “greenhouse effect” hypothesis while they are at it ????
Cheers, Kevin
Am I dense or not, is not the so called atmospheric green house affect not the direct heat of CO2 from the sun but from the warn earth at night? Is that not true? If it is both experiments are monumentally wrong. To duplicate atmospheric CO2 induced warming one would need a radiating body to conduct the experiment correctly. The radiating body would need to be something that is warm as or near the same temperature of the earth and of similar matter as the earth so that is would radiates in a spectrum similar if not the same as the earth at night. Sorry a lamp of any kind does not make it. I believe both experiments are invalid to begin with.