Talk:Greenhouse effect/Archive 6

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Please add Ice Age study

108.195.139.168 (talk) 08:25, 4 March 2013 (UTC)

The paper cited by the NYT looks like a reasonable source. However, als always with new papers, there is no rush - we should at least await formal publication, and probably at least the first round of reactions. Also, it might be better off at Ice core and possibly Global warming. --Stephan Schulz (talk) 08:44, 4 March 2013 (UTC)

Link to physics paper(s), where are they?

I understand that this is not a forum for general discussion of the article's subject, despite some talk in the above about what effectively is increasing and/or decreasing, and then putting up some learned opinion instead of a ref.

So here's my question to you experts: where are the links to physics papers, I mean the same ref that must have been used by the IPCC? 217.88.59.101 (talk) 13:31, 13 March 2013 (UTC)

Every Wikipedia page has a list of references at the end. Please see the "References" and "See Also" sections for the relevant material. 173.166.110.9 (talk) 17:00, 1 April 2013 (UTC)

General comments and corrections to improve quality of information

“However, human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming.”

Of the current 33 degrees C of greenhouse warming, only approximately 0.5 degrees C of that has been attributed to human activities. I suggest replacing "have intensified" with a more accurate "has contributed to some of".

“According to the latest Assessment Report from the Intergovernmental Panel on Climate Change…”

The Intergovernmental Panel on Climate Change is a political entity, not a scientific one. I suggest replacing all references of the Intergovernmental Panel on Climate Change with actual scientific peer reviewed journal articles.

“CO2 is produced by fossil fuel burning and other activities such as cement production and tropical deforestation.”

Cement also consumes as much CO2 during curing as is released during its production, resulting in a net cement production contribution of CO2 to the atmosphere of zero percent.

“The current observed amount of CO2 exceeds the geological record maxima (~300 ppm) from ice core data.”

The “record” cited only goes back a mere 800,000 years. In the last 100,000,000 years, CO2 levels have averaged 610 ppm with a peak of 1200 ppm, yet temperatures throughout this time period were similar to today's. See C.R. Scotese, http://www.scotese.com/climate.htm, for temp data and R.A. Berner, 2001 (GEOCARB III), http://www.geocraft.com/WVFossils/Reference_Docs/Geocarb_III-Berner.pdf, for CO2 levels.

“Over the past 800,000 years, ice core data shows that carbon dioxide has varied from values as low as 180 parts per million (ppm) to the pre-industrial level of 270ppm. Paleoclimatologists consider variations in carbon dioxide concentration to be a fundamental factor influencing climate variations over this time scale.”

Even if all paleoclimatologists consider something a fact, it doesn't make it fact since science is not a democracy. Let's not forget all scientists once considered the world flat and they were all wrong. Leave out the paleoclimatologist remark and replace it with "During the last glaciation, average global temperatures rose 9C as CO2 levels rose from 180ppm to 270ppm, yet in the last 100 years that CO2 levels have risen from 270ppm to 400ppm, the average global temperature has only risen 0.5C, so it is not clear what the actual fundamental influence on climate is at this time".

“The air continues to heat because it is confined within the greenhouse, unlike the environment outside the greenhouse where warm air near the surface rises and mixes with cooler air aloft. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature will drop considerably”

Increasing the convection rate in ANY AND ALL systems will also increase the cooling rate, so that does not demonstrate that ANY AND ALL systems act primarily by preventing convection. Furthermore, convection is not prevented from occurring in any greenhouse, since the only way to experimentally prevent convection is to limit the spacing between surfaces to one inch or less, as is the case with convection-limiting dual pane insulating windows. Anything over one inch will allow convection to freely occur between the surfaces. Remove the statement since it is false.

“It has also been demonstrated experimentally (R. W. Wood, 1909)...”

The reference cited is quoted from instead of actually linked to. If you actually read the reference cited, you will find it is hearsay by the author of what R. W. Wood allegedly demonstrated. No peer reviewed literature with Wood as the actual author is provided in the reference or anywhere else. Please strike the Wood's reference nonsense from the article so that its credibility will not be tainted.

“A runaway greenhouse effect occurs if positive feedbacks lead to the evaporation of all greenhouse gases into the atmosphere”

A "runaway" effect implies that no statis is possible. It occurs when a system's feedback mechanism is predominantly all positive or all negative. Also, the claim as stated doesn’t make any sense and is not supported by the reference cited. How much greenhouse gases would be required to cause a runaway effect? 500 ppm? 1000 ppm? Remove the statement since it isn't supported or logical.

HY1802D (talk) 18:45, 22 June 2013 (UTC)

Irradiation question

Query - amount of solar irradiation. I work with approx 1 kW/m2, as does another wikipedia page:

http://en.wikipedia.org/wiki/Sunlight

Your graphics show much lower values. Which is correct?

Ian Batty (ianbatty311@bigpond.com)

Both are, but they describe different things. Check the description at File:Greenhouse_Effect.svg. About 1000 W/m2 is the energy received on the ground if the Sun is directly overhead. But there is no Sun at all on the night side of the Earth, and the Sun is directly overhead only at one particular point on the Earth. So if you average over the full day (and year), the average amount of energy is much lower. Compare the surface area of Earth (4πR2) with the cross-section of Earth (πR2) to get the factor of ~4 between the two values. The rest is due to minor effects experts can probably explain. --Stephan Schulz (talk) 08:35, 7 July 2013 (UTC)

Bad Greenhouse

Bad Greenhouse looks like some useful [non-rs] explaining for a layman like myself. It contradicts our opening impeccably sourced wording "re-radiated in all directions"....

"One often hears the claim that the atmosphere absorbs radiation emitted by the Earth (correct) and then reradiates it back to Earth (false). The atmosphere radiates because it has a finite temperature, not because it received radiation. When the atmosphere emits radiation, it is not the same radiation (which ceased to exist upon being absorbed) as it received. The radiation absorbed and that emitted do not even have the same spectrum and certainly are not made up of the same photons. The term reradiate is a nonsense term which should never be used to explain anything."

Worth reconsidering? . . dave souza, talk 08:59, 30 July 2013 (UTC)

Hmm. Somewhere in our sentence ("... thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated ...") we omit to mention heat. The heat is transferred to the gasses, and that is what is then transferred again. Both transfers are by radiation. We're trying to be succinct. I don't think 're-radiate' is a nonsense term. 'Reflect' would be nonsense, and the quote above seems to be drawing a distinction between what happens and what would happen if reflection were going on, but it calls the non-existent reflection 're-radiation'. I think it's fair to call thermal radiation absorbed by the atmosphere and then emitted again as new radiation 're-radiation', but that it would be nonsense to call it 'reflection'. --Nigelj (talk) 22:34, 30 July 2013 (UTC)
Thermal radiation is the subject of both clauses of the opening sentence, so it still works out I think. Sailsbystars (talk) 01:00, 31 July 2013 (UTC)
There's more than one way to skin this cat. The web site linked gives one way of describing the greenhouse gas (surface heated by atmosphere+sun). But there are other equally valid ways, and re-radiation is one of them. The former is the point of view from a fixed point on the surface, re-radiation the point of view from the atmosphere. The third view is from space in which IR radiation from the surface is blocked by the absorption features. All three of these descriptions are correct, but all have various subtleties associated with them, which is unavoidable with a complex physical phenomenon. Sailsbystars (talk) 00:58, 31 July 2013 (UTC)
I prefer the sfc heated by sun+atmos formulation, since its the simplest. And we used that, at one point. Then people came in and elaborated it William M. Connolley (talk) 11:36, 31 July 2013 (UTC)

Failure to duplicate Wood's alleged 1909 greenhouse experiment

For those people who cannot understand that an unscientific peer reviewed journal (Philosophical Magazine) that indirectly references an experiment (an example of a friend of a friend of a friend said...) in which no specifics are given (how temperature was measured, what latitude, what time of year, how such a large, and therefore rare and expensive piece of rock salt glass was obtained, etc), here is link to someone that tried to reproduce the alleged Wood experiment and FAILED: http://boole.stanford.edu/WoodExpt/. Does anyone know how to escalate issues such as this? The alleged Wood's experiment is so flagrantly false. Also, atmospheric convection, while not as limited as it is in a greenhouse, is irrelevant since convection does not cool down the Earth, it merely transports heat from one area to another. Because the Earth is suspended in a vacuum, the one and only way for the Earth to lose or gain heat is via radiation. An actual greenhouse can get very hot due to the constraining of radiation, but not as hot as it could be because there is always some convection taking place -- inside and outside of the greenhouse -- preventing optimal heat retainment. If you examine the radiation budget of the Earth with the radiation budget of an actual greenhouse, they are very similar. So the Earth's greenhouse effect and an actual greenhouse do have a lot more in common than this Wikipedia article tries to make it out to be. I recommend that for credibility, remove the bogus Wood reference. HY1802D (talk) 03:30, 8 August 2013 (UTC)

how to escalate issues such as this: Yup. You submit your work to a proper journal for publication. I'd expect a prof, even an emeritus one, to know that. The alleged Wood's experiment is so flagrantly false - your own personal opinion, whilst doubtless very interesting to you personally, is not of interest to everyone else. Its also worth noting that VP refs Abbot who confirms Wood's major point "Agreeing with professor Wood that the main function... is to prevent loss of heat by convection" William M. Connolley (talk) 07:35, 8 August 2013 (UTC)
WMC's quote from Abbot's paper brings to mind the quote "Agreeing with Mrs Lincoln that it was a fine play" as proof that Mrs Lincoln had a great time at the theater. When WMC came to that innocent-sounding adverbial clause the rest of Abbot's 4-page quite damning critique of Wood suddenly became totally irrelevant to him.
Abbot is not the only one to question Wood's reasoning. A considerable history of this can be seen in this section of Bohren's book "Clouds in a Glass of Beer." There is also Edwin's Berry's refutation in 1974 of Lee's 1972 calculations supporting Wood's conclusion. I would have thought that the literature already has quite enough papers against Wood as to need no more, but WMC seems to believe otherwise for reasons that are doubtless very interesting to him personally. --Vaughan Pratt (talk) 09:27, 20 August 2013 (UTC)

"Greenhouse Effect" is the same as a "Runaway Greenhouse Effect"?

A Greenhouse Effect means heat is trapped more than usual, but it also means that more heat from the sun is added, and that causes a build-up of heat that just keeps building up hotter and hotter, until some factor changes (eg. less pollution, more photo-syntheses, or some other factor.) That is the REAL definition of a "greenhouse effect'. It is the same as a 'Runaway Greenhouse Effect", so the fact that it builds up hotter and hotter forever, unless some other factor changes, should be explained in the beginning. The current 'greenhouse gas' effect on Earth, if it is letting heat escape faster than it can build up, then it is not a greenhouse effect. It is just warmer. The real definition of a greenhouse effect is that the temperatures have 'runaway', such that the heat build-up continues, and unless something changes that, then it will not stop building up hotter. Its just to clarify terms. Its the same thing. — Preceding unsigned comment added by 24.63.50.134 (talk) 14:17, 19 August 2013 (UTC)

The mechanism by which Earth's greenhouse effect currently avoids runaway is explained much better in the article Infrared window than in this article. Section 3 of that article reads in its entirety, "Without the infrared atmospheric window, the Earth would become much too warm to support life, and possibly so warm that it would lose its water, as Venus did early in solar system history. Thus, the existence of an atmospheric window is critical to Earth remaining a habitable planet."
The atmospheric window creates a negative feedback in which rising surface temperature raises the rate of escape of heat to space from the surface and lower troposphere through the window. As the window closes due to increasing greenhouse gases, in order for the amount of heat escaping to space through the shrinking window to continue to balance the constant influx of heat entering Earth from the Sun, the temperature must increase, but only by a finite amount, i.e. no runaway. To a first approximation the amount of the increase is inversely proportional to the overall bandwidth of the remaining window. As that window bandwidth approaches zero the increase per cm−1 of lost bandwidth (a cm−1 is about 33 GHz) becomes much greater, until at a sufficiently small window the negative feedback becomes insufficient for further stable regulation and runaway sets in. Venus is well past that point but Earth is not. --Vaughan Pratt (talk) 21:26, 20 August 2013 (UTC)

Airless Earth would be 155K surely?

not likely to result in article improvement
The following discussion has been closed. Please do not modify it.

NASA Lunar Reconnaissance Orbiter’s DLRE has mapped temperatures on the Moon since 2009. The average temperature of the Moon’s surface is apparently 155K (about -133 degrees C below the average temperature of Earth). The average temperature of an airless Earth would therefore also be about 155K. Why does this article NOT explain why the atmosphere of Earth in fact raises its surface temperature by almost 133 degrees C to the average temperature we observe of 288K (15 degrees C)? Reference: http://lunar.gsfc.nasa.gov/diviner.html — Preceding unsigned comment added by 2.100.48.125 (talk) 22:18, 27 October 2013 (UTC)

I cannot find the 155K claim at your link. Did you simply average polar and equatorial temperatures? That would be wrong, because the areas are different (and the two extremes are not a sufficient indicator for overall average temperature). Also, the temperature of a body depends on its albedo, and also on its rotation. The Earth rotates roughly 29 times faster than the moon, which means it would have a much more even temperature, and since heat loss by radiation is proportional to T6 4, a body with more equal heat distribution will be, on average, warmer than a body with extreme temperatures under the same insolation. --Stephan Schulz (talk) 22:54, 27 October 2013 (UTC)
Typo? I think you mean T4, not T64--SPhilbrick(Talk) 17:44, 30 October 2013 (UTC)
If you look closely, the 6 is struck out - I had a moment of mental breakdown, but fixed it. I've put in a space to make the difference (maybe ;-) more visible. --Stephan Schulz (talk) 18:21, 30 October 2013 (UTC)
I think that's carrying the convention of strikeout too far. Better a parenthetical comment, and even that is overkill. No, I didn't catch it. I don't think anyone else will, but if they read on, they won't be mislead :)--SPhilbrick(Talk) 20:21, 30 October 2013 (UTC)

Stephen: Albedo doesn't help your argument. The Earth's albedo is 0.3 and the Moon's is 0.1. That makes Earth COOLER than the Moon, right? Anyway, I can’t find this data on the NASA Diviner site either. Ashwin R Vasavada et published a paper in the Journal of Geophysical Research April 2012 “ Lunar equatorial surface temperatures and regolith properties from the Diviner Lunar Radiometer Experiment”. A link to this paper still works on

http://tallbloke.files.wordpress.com/2012/04/lunar-equatorial-surface-temperature_2012.pdf

This work confirms the Appolo mission data that the equatorial temperature of the Moon is a constant cool 240K just 300mm below the surface. We also know the Moon pole temperatures are around 50K. So you don’t need to be an astro-physicist to work out that the average surface temperature of the moon is between these limits (50K<average moon surface temperature<240K). Has somebody at NASA now measured the actual average surface temperature from the Diviner data? I’ve tried a few links: http://www.diviner.ucla.edu/science.shtml Also found a later paper http://www.lpi.usra.edu/meetings/lpsc2013/pdf/2492.pdf — Preceding unsigned comment added by Techtick (talkcontribs) 13:45, 28 October 2013 (UTC)

Actually, the below the surface temperature is more or less the same for the entire moon. You're comparing apples and oranges here. The pole temperatures are only 50K in the permanently shadowed craters - for the most part there's not a strong polar temperature gradient on the moon. In the LPI paper you list, you'll note that the surface temperature is 400K in the day time, not 240K. The average temperature for the moon is therefore around the 240K subsurface temperature, since the solar heating propagating downward and interior cooling propagating upward equalize at this temperature. It's possible that the average surface temperature is 155K, but that doesn't mean the equilibrium temperature for the moon is 155K. If the moon had a grey (i.e. non-greenhouse) atmosphere and/or was a more rapid rotator, it would have a surface temperature closer to equilibrium. The interior, however, still retains a temperature close to thermal equilibrium under current conditions. Sailsbystars (talk) 15:27, 28 October 2013 (UTC)
For instance, here's a paper with long wavelength observations (i.e. probing a few meters under the surface) and they find that the temperature of the moon is 233K +/- 10K across the surface. Sailsbystars (talk) 15:32, 28 October 2013 (UTC)
Just to clarify: My argument was generic - you cannot assume that the moon and the Earth would have the same surface temperature if they both had not atmosphere. Not also that the albedo of an airless Earth would probably be different from the current one. Also, what SBS says ;-). --Stephan Schulz (talk) 16:02, 28 October 2013 (UTC)

Mmm, OK, so 155K for the Earth is wrong. But the usual formula (e.g. [1] applied to the moon with albedo of 0.1 gets you ~273K, not 233K. I'm not sure where the 40K difference comes from. Possibilities: the albedo isn't really 0.1 (the albedo page says regolith is funny like that); lacking an atmosphere the non-linearity that Stephan mentions really is important William M. Connolley (talk) 18:34, 28 October 2013 (UTC)

Its the non-linearity. Rough calcs: a body with albedo 0.1 (SW; 0 in lW) at 273K radiates ~1370. At 360K, 4232. At 100K, 25. So if the body spent half its time at 360K, and half at 100K, for an average temp of 230K, it would radiate more than one roughly constant at 0K William M. Connolley (talk) 18:46, 28 October 2013 (UTC)
When averaging a quantity whose square is conserved, one uses root mean square. In this case radiation dominates, where it is the fourth power of temperature that is conserved. Hence for a physically meaningful notion of average temperature one should take the fourth root of the average of the fourth power of temperature. Vaughan Pratt (talk) 20:31, 28 October 2013 (UTC)

I agree, William. Ned Nikolov et al papers confirm you have really got to mess with the albedo to get the S-B predicted temperatures of the moon to match measurements being made by NASA. https://fp.auburn.edu/sfws/sfnmc/web/nsz.pdf — Preceding unsigned comment added by Techtick (talkcontribs) 22:02, 28 October 2013 (UTC)

... ... ... That's not a scientific paper. I don't understand what they did wrong (hell, I don't understand what they did, and nature seems to have rejected their paper), but their conclusions are complete rubbish and at odds with the observational evidence that the moon has a nearly uniform brightness temperature of 233K in the subsurface at L-band, corresponding to an average physical temperature of ~245K, which matches predictions from the simple planetary equilibrium model to within 20K (suspect this discrepancy is due to slow rotation -> hotter surface -> more radiation). They flat out lie about the Diviner results, which use an average lunar temperature of 240K in their models, not 197K. Sailsbystars (talk) 23:24, 28 October 2013 (UTC)
Also, it's worth pointing out that the Earth's 0.3 albedo has a lot to do with things like clouds. Remove Earth's atmosphere, and you remove a bunch of its albedo. --OuroborosCobra (talk) 00:32, 29 October 2013 (UTC)

The NN paper is odd, because it uses a Moon avg sfc temperature (-76 oC) that is much colder than everyone else uses. However, insofar as I can see, all the rest of it is saying is that you need to do the averaging properly, taking account of non-linearities, if you want to use S=rT^4 to calculate an average temperature. That's correct, but no-one disagrees with it either, so that's hardly new or controversial. They seem to be very hung up on what the Earth's temperature would be in the absence of an atmosphere. As OC points out, part of that depends strongly on clouds, since they affect albedo, and the result would be different without an atmosphere. Less obviously, without an atmosphere the dayside-nightside differences become larger and non-linearity becomes more important (as I've pointed out above). I haven't checked their derivation of equation (2), although its plausible. However the most important point is that this has absolutely no implications for general climate science at all - its all about how you might calculate an imaginary quantity, the temperature of an Earth with no atmosphere but the same albedo (etc) as now. So the title of the NN piece - "What if Climate Models are wrong?" bears no relationship to its contents; their figure 1 is irrelevant to their paper and their conclusions (last half of the last para) simply don't follow from their arguments.

The number they seem worried about - the 33K ascribed to the GHE on Earth - doesn't figure anywhere in any of the GCMs or any of the theory. Its a toy number, used for exposition only. Exactly what it would be depends on various assumptions you make about your imaginary airless Earth (and it doesn't have to be airless: you can instead make up an Earth with no GHG's in the atmosphere) William M. Connolley (talk) 09:14, 29 October 2013 (UTC)

William, it says in the Wiki here "If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C." My problem is: We all know this is scientific rubbish when describing spherical objects such as planets, so, why does everybody ignore such an obvious nonsense statement without question? Do you agree the Wiki statement or is the statement scientific "rubbish" ?— Preceding unsigned comment added by Techtick (talkcontribs) 19:56, 29 October 2013 (UTC)

OuroborosCobra and Sailsbystars, I'm always interested in learning something new. L-band observations, impressive! Wiki says https://en.wikipedia.org/wiki/L_band these are more to do with mobile phones and military frequencies. Observations from Earth in these frequency bands must be a bit, shall we say "dodgy", or do you just accept them without question? — Preceding unsigned comment added by Techtick (talkcontribs) 20:52, 29 October 2013 (UTC)

Errm, why is "If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C." rubbish? Are you objecting (a) to the premises, or (b) the conclusions from those premises? If (a), then you're wrong to describe it as rubbish: its merely an idealised thought experiment William M. Connolley (talk) 22:05, 29 October 2013 (UTC)
When astronomers talk about L-band, they're almost always talking about observations near the 21 cm line which is in a protected radio astronomy band due to its use as the main tracer of the structure of our galaxy. Furthermore, terrestrial interference, even if it did exist, is easily excised from interferometers, such as the Dominion Radio Astrophysical Observatory which is the instrument that made the observations I referenced. So interference can be a problem, but radio astronomers have thought of it and it is such a long-resolved problem that it almost never even gets mentioned in papers anymore unless they're working in really heavily polluted bands like FM radio. Sailsbystars (talk) 05:49, 30 October 2013 (UTC)

William, OK you're the expert. Does a blackbody at our orbit from the sun have a temperature of 5.3 degrees or not? — Preceding unsigned comment added by Techtick (talkcontribs) 22:36, 29 October 2013 (UTC)

You didn't answer my question, which is hardly polite: choose (a) or (b), please. But I'll answer yours: there are no such objects, so in talking of a "blackbody" you're asking about an imaginary object. But you haven't fully described the imaginary object, so your question cannot be answered as-is. But if I say the imaginary object is perfectly spherical, perfectly conducting, and a perfect black body at all wavelengths then yes: its surface temperature would be 5.x oC (though I make x 2, not 3) William M. Connolley (talk) 10:41, 30 October 2013 (UTC)

William, sorry. I should have answered your questions and qualified which parts of the "rubbish science" in this Wiki article wants correcting. a) A superconducting black sphere at our orbit would in theory have a temperature of about 5 degrees C. b) Earth and Moon are really bad conductors of heat so blackbody analogy is "rubbish" without a full explanation of the difference between the hypothetical and real planet. Why start a serious explanation of "greenhouse effect" from such a poor analogy? — Preceding unsigned comment added by 80.44.53.95 (talk) 14:55, 30 October 2013 (UTC)

"all models are wrong, but some are useful". Sailsbystars (talk) 15:08, 30 October 2013 (UTC)

OK, I accept "All models are wrong" (that includes climate models!) but why can't we start from an analogy with our nearest planet (where we have lots empirical data to start with) and work the Earth differences from there (rotation, albedo, gas laws, etc.)? — Preceding unsigned comment added by Techtick (talkcontribs) 15:26, 30 October 2013 (UTC)

Because the planetary equilibrium temperature is the simplest available model which derives the correct order of magnitude of the greenhouse effect on three different planets. Using that model, you get that the GH effect is 100s of K at Venus, 10s of K at Earth, and a few K at Mars, which are the correct values to factors of order unity. So the model is useful, even though it misses a lot of stuff. And its accurate to a few % for a rapidly rotating body (i.e. periods <~1 day, e.g. asteriods). Sailsbystars (talk) 15:33, 30 October 2013 (UTC)

Sailsbystars, Mars and Venus have about the same carbon dioxide proportions in their atmospheres. NASA says BB temp of Venus 184K, observed surface temp 738K and Mars has BB 210K and observed surface temp 210K. BB temp seems a bit simplistic for any greenhouse effect model that makes sense? — Preceding unsigned comment added by Techtick (talkcontribs) 16:29, 30 October 2013 (UTC)

What is relevant (as always, in the first approximation) for the GHE is not the proportion, but the absolute amount of greenhouse gases. --Stephan Schulz (talk) 16:47, 30 October 2013 (UTC)

Stephan, I accept that. So if there is no more gas being added to Earth's atmosphere, the rise in CO2 proportion we've seen in the last 100 years won't affect things at all, true? — Preceding unsigned comment added by Techtick (talkcontribs) 18:31, 30 October 2013 (UTC)

I'm not quite clear about your question. If we add more CO2, we increase the greenhouse effect. If we also add a fully transparent gas, that would reduce the proportion of CO2, but would not reduce the greenhouse effect. If we remove a fully transparent gas (Nitrogen comes close enough), keeping CO2 the same, the proportion of CO2 would increase, but that would again not have a strong effect on the greenhouse effect. However, the atmosphere influences temperatures in other ways as well - it acts e.g. as a buffer and also contributes to heat distribution on the surface. There is about 15000 times more CO2 in the Venusian atmosphere than in the Martian atmosphere, even if the relative contribution of CO2 is ~96% in both cases. That's why the greenhouse effect is much stronger on Mars than on Venus. --Stephan Schulz (talk) 20:25, 30 October 2013 (UTC)
(ec)Huh? That makes no sense. CO2 is rising, both as a proportion and in absolute amount. It is the absolute that matters, not the proportion, but I'm not following your conclusion.--SPhilbrick(Talk) 20:27, 30 October 2013 (UTC)

Ok, let me put it another way. Let's assume CO2 in Earth's atmosphere rises to 1% (I guess oxygen will have to go down to achieve this). What in your view would be the new surface temperature of our planet - How do you calculate it? — Preceding unsigned comment added by Techtick (talkcontribs) 22:51, 30 October 2013 (UTC)

I'd use the climate sensitivity. The best estimate currently is around 3K per doubling of CO2. We are at around 400ppm now. 1% is 10000ppm, so that's a factor of 25, or ~4.64 doublings. So temperatures would rise about 14K, or a bit more, since we are not yet in equilibrium with respect to the current 400ppm. There is significant uncertainty in the climate sensitivity, and for such a big increase, there probably will be serious second-order effects, so this will only give you a rough idea. --Stephan Schulz (talk) 23:11, 30 October 2013 (UTC)
(ec)Did you miss a decimal point? The current level is roughly 400 ppm. 1% is 10,000 PPM. The growth is, very roughly 2 PPM. So it would take a little under 5000 years to get to the level. What would be the point of the exercise?--SPhilbrick(Talk) 23:16, 30 October 2013 (UTC)

What’s the point? What’s the point? What’s the point of Wikipedia if we don’t try to keep it up to date as human knowledge advances? My first point is: I agree with the heading of this talk point. There is something seriously wrong with the “science” presented in this wiki article. A planet made of much the same stuff as Earth, at our orbit, almost airless and waterless, appears to have an average surface temperature near 155K. GH gasses, Earth albedo, oceans, etc. appear to raise the temperature here on Earth by about 133K. What’s the point of trying to convince everybody that the GH effect is only 30 degrees C when it’s probably more? My second point is: I don’t believe that changing the mix of CO2 and O2 by up to 1% of the composition mix of our atmosphere will change the surface temperature at all. I just want somebody to give me the proof I’m wrong. I don’t wiki stuff expecting to read nonsense! — Preceding unsigned comment added by Techtick (talkcontribs) 09:42, 31 October 2013 (UTC)

Have you read any of the preceding answers? The moon has a very different surface, very different rotation, and I don't think we have seen any reliable source that confirms the "average surface temperature near 155K" claim (and notice that the "average surface temperature" is not the same as the equilibrium temperature). Your second point is simply weird. Science does not do "proof", but the difference between CO2 and O2 is that CO2 is opaque at many of the wavelength the Earth radiates in, while O2 is transparent. Hence CO2 traps heat in a way that O2 does not. --Stephan Schulz (talk) 10:14, 31 October 2013 (UTC)

Stephan, I bet if we sent you to the Moon with a thermometer, you’d still come back arguing it was defective in some way. Ok what’s wrong with Gary Novak’s work here http://lasersparkpluginc.com/uploads/CO2_Absorption_Data.pdf I'm getting bored with this conversation. When you "scientists" post a more convincing "story" of GH effect - I'll read! — Preceding unsigned comment added by Techtick (talkcontribs) 11:40, 31 October 2013 (UTC)

Sorry, I thought we were talking about the apparently unfounded claim that the Moon has an "average" surface temperature of 155K (with no definition of "average" and no clear source), and into differences between the Earth and the Moon that cause both bodies to demonstrate different thermal behavior. I didn't know we were into general green-house-effect denial. Novak's paper is self-published, and is basically replicating Ångström's work from the turn of the previous century. This is well-understood to be wrong (and has been for ~80 years). Interestingly, Novak does not cite Angstrom, or indeed anyone but another self-published web site - apparently he has not done his homework. See e.g. [2] for some sources which have. --Stephan Schulz (talk) 12:34, 31 October 2013 (UTC)

OK, This is my last posting here. I do not deny GH effect. On the contrary, I say this wiki article underestimates its effect by maybe 100K. Without a proper scientific approach to explaining why it's of the order of 133K, you'll never understand the effects of small changes of insolation, the real effects of atmospheric gas mix changes, or worst case albedo changes leading to the next ice-age. (Perhaps you take the view there will never be another ice-age? Well, none of us will be here to read this!) BTW, Wrong Angstrom link try: http://claesjohnson.blogspot.co.uk/2013/01/angstrom-inventor-of-pyrgeometer-and-dlr.html— Preceding unsigned comment added by Techtick (talkcontribs) 13:48, 31 October 2013 (UTC)

The moon's average temperature across the surface is clearly 240-250K as I showed you many times above directly observed by radio astronomy. You have given no evidence for why the average temperature is actually 155K, except for a rubbish paper that got rejected from various journals because they fail mathematics forever and couldn't be bothered to look at the vast amounts of observational disproof. I propose we hat this discussion and consider a WP:NOTHERE ANI report for Techtick, as there are zero suggestions for anything that would improve this article. Sailsbystars (talk) 15:13, 31 October 2013 (UTC)
Let me add that it was indeed Knut Ångström who measured the absorbance of IR by CO2 and wrongly concluded that Svante Arrhenius was wrong. --Stephan Schulz (talk) 16:46, 31 October 2013 (UTC)

This has become pretty silly. Techtick had an interesting point (dunno if he actually realised it, but it came up in the discussion) that non-linearity means that the average temperature of a non-superconducting-body isn't the straightforward one. But our article very clearly states "If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C. However, since the Earth reflects about 30%[5][6] of the incoming sunlight, this idealized planet's effective temperature (the temperature of a blackbody that would emit the same amount of radiation) would be about −18 °C" so our article is entirely correct (and not only is it entirely correct, its also correctly sourced, so even were it wrong which it isn't, it would still be policy-compliant).

All that is separate from My second point is: I don’t believe that changing the mix of CO2 and O2 by up to 1% which std.drivel, and should be ignored entirely. Time for the man with the cot tag methinks William M. Connolley (talk) 17:24, 31 October 2013 (UTC)

Why is the above discussion closed?

I posted this question [3] because of the (above) discussion about GHE on other planets, particularly about planets with little or no atmosphere, was (is?) entirely relevant and the article would be considerably improved if the current minimal material was expanded.

I post here now because the responsible Vsmith has not yet explained why he closed the discussion. --Damorbel (talk) 20:30, 1 November 2013 (UTC)

Ho hum. Another round of WP:WASTEOFTIME looms. Still, its a friday night William M. Connolley (talk) 21:39, 1 November 2013 (UTC)
(edit conflict) Because the above thread is nothing but a bunch of nonsense from a user who is unwilling to actually learn basic physics, or quite frankly, reality. If you have constructive suggestion for expanding, that would be swell. The "bodies other than earth section" could definitely be expanded, and I can think of some sources that would be useful in that regard. You think maybe a bit more explaining why Mars has a weaker GH effect than Earth, and Earth than Venus would be a useful addition? There was potentially useful material in the above thread I guess, but it got derailed by the nonsense, which is why the thread was hatted. Sailsbystars (talk) 21:43, 1 November 2013 (UTC)
Care to say why it's nonsense? Considering the Science Museum says
Mars’s greenhouse effect is actually very weak.
and Mars’s
atmosphere is 95% carbon dioxide
I really don't see how this can be 'irrelevant to the article' or 'a waste of time.'

--Damorbel (talk) 07:18, 2 November 2013 (UTC)

Have you read the preceding section? 95% of very very little is still very very little. In fact, it's slightly less. --Stephan Schulz (talk) 07:22, 2 November 2013 (UTC)
But Stephan, we don't actually explain that in the current article. It might be better to update the section to say something like:
"Mars and Venus both have a greenhouse effect as well. For Mars, while the atmosphere is almost entirely CO2, the greenhouse effect there is very weak since the greenhouse effect is proportional to the total amount of greenhouse gas rather than the percentage and Mars' atmosphere is very thin. In the past, however, Mars is thought to have had a more substantial atmosphere and thus greenhouse effect due to abundant evidence that liquid water once flowed upon its surface. Venus, on the other hand, has both a thicker atmosphere than Earth and an atmosphere of mostly GHG. As a result, Venus has a scorching surface temperature of 740K. Thus greenhouse gases are thought to play an important role in determining the habitable zone of a star, as Mars and Venus today have environments incompatible with life, but planets with a different amount of greenhouse effect at those locations could have liquid water on the surface."
An aside, Mars actually has an absolute value of CO2 10x that of earth by my quick calcs (5e-3 atm pressure -> 5000 ppm equivalent) so the thin atmosphere bit I think might be a bit of an oversimplification (i.e. lack of water vapor and other factors also play into it). Sailsbystars (talk) 14:34, 2 November 2013 (UTC)
I wasn't sure how to compute total atmosphere equivalent for different sizes and gravity fields (and I was too lay to even try to set up any integrals ;-), but in general, "yes". We probably need sources, though. --Stephan Schulz (talk) 15:01, 2 November 2013 (UTC)
Duh! Given that the effective depth of the atmosphere is small compared to the diameter even of Mars, we could probably just divide the total mass of the atmosphere by the surface area for a good enough approximation. I'm not used to thinking in physical terms anymore ;-). --Stephan Schulz (talk) 15:04, 2 November 2013 (UTC)
As the article correctly explains (albeit incomprehensibly succinctly), "It is more realistic to think of the greenhouse effect as applying to a "surface" in the mid-troposphere, which is effectively coupled to the surface by a lapse rate."
Page 8 of Nicolas Thomas's slides on the Martian atmosphere gives Mars' lapse rate as 1.6 K/km. The result is that even though Mars is getting only a fraction of the insolation Earth receives, Mars' mid-troposphere is hotter than about the same temperature as Earth's as can be seen from Thomas's next slide, in fact on Mars it is centered on close to 210 K at all altitudes from 0 to 40 km!
Hence that surface, which as a function of frequency of OLR can be thought of as the planet's photosphere, radiates about as much heat as its counterpart on Earth, despite the fact that Mars receives considerably less insolation than Earth. This low lapse rate effectively shuts down the greenhouse effect on Mars completely, which is why Mars' surface temperature ends up being so close to its effective temperature.
Lapse rate also explains Venus's high surface temperature. Venus's lapse rate is close to Earth's, very roughly 10 K/km. The main difference is that (in very round numbers) Venus's OLR photosphere is some 40 km higher than Earth's, which therefore adds some 40*10 = 400 K to Earth's surface temperature.
Since Venus's bond albedo is a very high 0.9, her greater proximity to the Sun relative to Earth does not play as important a role as one might think. Further even the 10% of insolation that Venus absorbs mainly heats the clouds above 65 km, and a mere trickle of 20 W/m2 or so of orange-colored sunlight reaches the surface, just enough to maintain the adiabatic lapse rate.
For both Venus and Mars, Planck feedback (the rise in surface temperature responding to a narrowing of the atmospheric window) is negligible on both Mars and Venus. This is so on Mars because the window is effectively wide open, while on Venus it is effectively completely closed. GHG-induced global warming can only operate when the GHGs can nontrivially impact the width of the window. Vaughan Pratt (talk) 01:18, 14 January 2014 (UTC)
I should add that doubling Venus's CO2 can still raise the surface temperature. However this will not be the result of narrowing the atmospheric window, and hence will not obey Arrhenius's logarithmic law which is a consequence of the logarithmic distribution of CO2's absorption line strengths. Rather it will be the result of raising the altitude of Venus's OLR photosphere. Every additional 10 km of altitude will add some 100 °C to the surface temperature, entirely driven by lapse rate rather than Planck feedback. In principle enough extra CO2 could raise the surface temperature to 1000 K, as well as increasing the pressure at the surface to the point where the atmosphere was more like a liquid than a gas (unless the higher temperature more than offset the higher pressure, interesting question). Vaughan Pratt (talk) 23:57, 15 January 2014 (UTC)
I haven't had time to fully digest your explanation, but i think it makes sense. Don't know how we can incorporate into the article at an appropraite level, but I wanted you to know I appreciate you taking the effort. Sailsbystars (talk) 01:25, 16 January 2014 (UTC)

Semi-protected edit request on 11 February 2014

The third sentence of the "Real Greenhouses" section again starts talking about the greenhouse effect (not real greenhouses). My suggestion would be to start the third sentence: "In contrast, the greenhouse effect heats the earth because..." SharpPack (talk) 15:36, 11 February 2014 (UTC)

Seems reasonable, made the suggested change. Vsmith (talk) 16:14, 11 February 2014 (UTC)

Greenhouse Effect

NOR

The radiative greenhouse effect conjecture is demolished by the Loschmidt gravito-thermal effect which is clearly evident in a Ranque-Hilsch Vortex tube for example, as well as in all planetary tropospheres.

It is wrong to assume Loschmidt's gravitationally induced thermal gradient does not evolve spontaneously in a gravitational field. It is the isentropic state of maximum entropy with no further unbalanced energy potentials. You cannot explain why the Venus surface temperature rises by 5 degrees spread over the course of its 4-month-long day with any radiative forcing conjecture or greenhouse philosophy. The Venus surface receives barely 10% of the direct Solar radiation that Earth's surface receives. It would need over 16200 W/m^2 if radiation were heating the surface. Then, during sunlit hours it would need an extra 450W/m^2 to raise the temperature from about 732K to 737K. On Earth, if isothermal conditions were supposedly existing without water vapor and other greenhouse gases, then the sensitivity to water vapor would be about 10 degrees per 1% atmospheric content. But there is no evidence that a region with 1% above it is 30 degrees colder than another region at similar altitude and latitude with 4% above it. The effective surface layer of Earth's oceans may be considered to be only 1cm thick, or even if 10cm thick it is still very transparent to insolation. But a black or grey body does not transmit radiation, and the surface layer absorbs less than 1% of that incident solar radiation. So the S-B calculations are totally incorrect and planetary surface temperatures cannot be calculated using such.

This is where the error crept in in 1985 [1] ...

"Coombes and Laue concluded that answer (1) is the correct one and answer (2) is wrong. They reached this conclusion after finding that statement (2a) is wrong, i.e., the average kinetic energy of all molecules does not decrease with the height even though the kinetic energy of each individual molecule does decrease with height.

These authors give at first a qualitative explanation of this fact by noting that since both the kinetic energy of the molecules and the number density of molecules decrease with height, the average molecular kinetic energy does not necessarily decrease with height."

This is absurd. They had the mean kinetic energy decreasing in each molecule, but then they divided again by the number. Try calculating a mean by dividing twice by the number of elements. A glaring error. The Loschmidt effect has NOT been debunked by this nonsense.

Nor has the Loschmidt (or gravito-thermal) effect been debunked by Verkley et al [2] because they made the mistake of working with enthalpy, rather than entropy, which is all that the Second Law of Thermodynamics refers to. An isothermal state would have unbalanced energy potentials in a vertical plane because it would have more mean gravitational potential energy per molecule at the top. Hence it is not the state of thermodynamic equilibrium with maximum entropy.

A good example of the gravito-thermal effect can be found in the nominal Uranus troposphere where the base is hotter than Earth's surface despite there being no significant direct solar radiation or internal energy source, or any surface. The thermal gradient in the Uranus troposphere works out to be very close indeed to the negative quotient of the acceleration due to gravity on that planet and the weighted mean specific heat of the gases in the troposphere.

[1] Velasco, S., Román, F.L., White, J.A. (1996). On a paradox concerning the temperature distribution of an ideal gas in a gravitational field, Eur. J. Phys., 17: 43–44.

[2] W.T.M.Verkley et al "On Maximum Entropy Profiles" http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(2004)061%3C0931%3AOMEP%3E2.0.CO%3B2

Douglas Cotton (talk) 02:28, 1 April 2014 (UTC)

No. Sailsbystars (talk) 03:56, 1 April 2014 (UTC)

Heat transfer

Aded lede to heat transfer, here. Prokaryotes (talk) 19:27, 6 April 2014 (UTC)

Cosmic Microwave Background – Proposed Edit to this Article.

WP:NOTFORUM. Also WP:NOTABASICPHYSICSCLASS Sailsbystars (talk) 19:11, 8 May 2014 (UTC)

In the third paragraph an edit is required. The argument must take into account CMB thermal black-body heating of Earth. Wiki and many other peer reviewed papers state: The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K. (e.g.: Reference Wikipedia http://en.wikipedia.org/wiki/Cosmic_microwave_background). The edit suggested is: ”Earth’s actual surface temperature of approximately 14 °C.[9] About 10% of the difference between the effective and actual temperature is accounted for by Cosmic Microwave Background heating of the Earth, the remaining 90% is known as the greenhouse effect. “ — Preceding unsigned comment added by 92.26.154.12 (talk) 20:35, 5 May 2014 (UTC)

Can't. We'd need a reliable source, and I think the numbers in the intro take into account the CMB... Sailsbystars (talk) 01:37, 6 May 2014 (UTC)
Total energy from CMB is trivial, no? William M. Connolley (talk) 14:20, 6 May 2014 (UTC)
Ah yes indeed. Even though it's whole sky, T^4 term dominates. A quick calculation shows that the sun's heating is ≈10^8 more than the CMB. The IP OP is assuming a linear relationship where none exists. Sailsbystars (talk) 14:32, 6 May 2014 (UTC)

The Cosmos contains mega,mega, mega, etc. millions of tons of GHGs all apparently radiating heat back to Earth. Why is this insignificant? — Preceding unsigned comment added by 92.26.154.12 (talkcontribs) 19:41, 7 May 2014‎

Breaking news, apparently the Earth isn't the centre of The Cosmos! Got a source stating how these GHGs work on anything other than sunlight, and if so how much actual heating in W/m2 at Earth's surface? . . dave souza, talk 19:51, 7 May 2014 (UTC)
Because it's either a.) really really cold (the CMB -- which incidentally doesn't contain GHGs, only H, He, and Li) or b.) a minisccule fraction of the sky (e.g. distant nebulae, other planets). You might want to read up on Olber's paradox, which sounds like what you're talking about. Sailsbystars (talk) 19:53, 7 May 2014 (UTC)

Ah! It seems it is not just GHGs which warm the Cosmos. Do the authors of this article deny the theory of 2.73K heating of the Cosmos? It is trivial to show how this heat affects Earth’s surface temperature. If we could “turn-off” the Sun and wait a few million years for Earth to reach a new equilibrium temperature, would Earth’s temperature tend towards absolute zero or 2.73K? Now let’s turn the Sun back on again. The Earth’s temperature would then rise from 2.73K by adding the ideal thermally conductive blackbody temperature theory stuff expounded in the opening paragraphs. Trivial, no? So once you introduce the Sun and Earth into the real Cosmos, CMB deniers will have to explain how the Sun destroys the energy background of the Cosmos to end up at 5.3C. No? — Preceding unsigned comment added by 92.26.154.12 (talk) 12:50, 8 May 2014 (UTC)

This ain't a forum. Unless you provide a reliable source showing in full the argument you're proposing, this section will be archived. . . dave souza, talk 13:08, 8 May 2014 (UTC)
Perhaps less policy-based, but more enlightening: Due to the term of the Stefan–Boltzmann law, the cosmic microwave background is essentially negligible for the radiative balance. There is about two orders of magnitude in the absolute temperature of the CMB vs. the Earth, but that translates to a factor of between the CMB radiation and the Earth radiation. In other words, at ~270K, the CMB only causes about 0.00000002 degrees of difference in the surface temperature. --Stephan Schulz (talk) 13:20, 8 May 2014 (UTC)
Thanks, Stephan, a useful explanation for us non-experts. It did strike me that there was a considerable difference between 2.73K and 5.3C. . . dave souza, talk 16:50, 8 May 2014 (UTC)

Ah! You need references to believe in CMB. Well, let’s start with a science non-entity like Stephen Hawking: ”The radiation left over from the Big Bang is the same as that in your microwave oven but very much less powerful. It would heat your pizza only to -271.3°C, not much good for defrosting the pizza, let alone cooking it.” He implies CMB would heat pizzas on Earth to 2.73K. Fancy that! I’m not going to insult scientists of the caliber of Stephen Hawking by saying he needs references to avoid being archived. Are you? — Preceding unsigned comment added by 80.44.212.218 (talk) 18:34, 8 May 2014 (UTC)

Note Hawking's preposition. It's "to", not "by". Also note that the "on Earth" seems to be your personal interpretation - it's really quite hard to heat anything to 2.73K on Earth (because you won't find anything that needs heating). Also note that your (or Hawking's?) math is a bit off, -271.3°C is only 1.88K. Since the CMB is roughly 2.73K, it would heat a pizza in otherwise empty space to -270.43°C (unless my math is off, which is a very real possibility at any time, but especially when I lecture about other peoples shortcomings). --Stephan Schulz (talk) 11:33, 9 May 2014 (UTC)

Greenhouse effect is a misnomer

The greenhouse effect can be simply explained by the colouring imparted to the atmosphere by any so-called greenhouse gases. In 'radiation widows', wavelengths where the atmosphere is transparent, radiation from the surface, at an average temperature of 14.5C, can convey heat directly to space. But where the atmosphere is coloured, for example around the 15 micron CO2 band, upward radiation is absorbed after a short distance, then re-emitted and reabsorbed. In this what heat is transported upwards by a process akin to diffusion or by convection. It is only from high altitudes that the heat can finally radiate into space and here the temperature is very much lower, due to the thermodynamic lapse rate. Thus from space the Earth can 'appear' to be at the black body temperatue of -18C. The measured spectrum can be seen by searching for "earth radiation spectrum". It is clear that at 15 microns the altitude from which radiation is emitted extends well beyond the tropopause. The term 'Greenhouse' reinforces the fallacy in the minds of the public (and I suspect many politicians) that a 'layer' of CO2 is 'reflecting' heat back to the surface. Of course there is no such layer and CO2 does not refect. The controversy concerning the prediction of the influence of increasing levels of CO2 on future temperatures could have a resolution. Such spectra have been measured over a period of decades. Over that time the concentration has risen by some five percent of its value. A comparison of recent and historical spectra would go far to settling the matter one way or the other.Billingsley John (talk) 05:29, 13 October 2014 (UTC)

What is it you are thinking is not settled? What to call the effect? Seems settled to me. Dicklyon (talk) 06:43, 13 October 2014 (UTC)
I think he might be talking about Greenhouse effect#Real greenhouses William M. Connolley (talk) 19:20, 13 October 2014 (UTC)
Since he doesn't mention greenhouses, he's more likely objecting to the back-radiation account and preferring the (more or less equivalent) lapse-rate account given in bullet point 3 of the article's Mechanism section. However his reasons for preferring the latter, namely that the back-radiation account is via reflection, and is from a single layer, are both straw men: the article speaks not of reflection but of re-radiation back towards the surface, and uses "layers" (the effect can be computed numerically by analyzing a column of atmosphere as consisting of many thin layers), not "layer", neither of which are fallacious. Also CO2 rose by 5% over the past 9 years, not "over a period of decades" as he claims. The parts of his comment that are correct are in good agreement with the article. Vaughan Pratt (talk) 14:56, 14 October 2014 (UTC)

Term Greenhouse effect as it relates to global warming is a misnomer. Why have an article that calls something something it is not particularly when the very existence of it is open for debate. A greenhouse warms up inside because the ground underneath it warms up. This is the only statement in the article regarding a greenhouse effect that is true.

"The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.[2][3][4]"

This one below is false:

'The surface temperature of this hypothetical planet is 33 °C below Earth's actual surface temperature of approximately 14 °C.[9] The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect.[10]'

</ref> "Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics" Gerhard Gerlich, Ralf D.Tscheuschner, Version 4.0 (January 6, 2009)http://arxiv.org/pdf/0707.1161.pdf

This 33 °C is commonly miscalculated. There are many other statements in here disproved or at least open for debate. Also re-radiation is not an accepted term in physics especially when it violates the "Second Law of Thermodynamics" which states that heat transfer is from hot to cold not the other way around. How many pages of misnomers are allowed on Wikipedia? Something wrong is widely accepted that way so just leave it as is? Ridiculous!

Carbon Dioxide increases AFTER a rise in temperature not before. The records show this. This article should be eliminated based on this scientific proof from this source and this one

</ref> "Climate Change Re-examined" JOEL M. KAUFFMAN (2007) http://citeseerx.ist.psu.edu/viewdoc/download?rep=rep1&type=pdf&doi=10.1.1.175.4704 Bbigjohnson (talk) 15:27, 3 April 2015 (UTC)

Semi-protected edit request on 18 November 2014

The first paragraph in the section titled as "Mechanism" makes an unsubstantiated, unproven statement when it says that the warming of earth is greater with the atmosphere than what would occur without the atmosphere. This statement ignores the 30% of solar energy that this title accepts as the amount of reflected solar energy by the atmosphere. The net effect of the presence of an atmosphere is protective because of this reflecting of energy and this is evident when planets without an atmosphere are seen to be very hot in daylight and cold at night. This reflection is dependent on the quantity/density of gases present. This single fact makes the entire argument concerning the effect of rising CO2 to be incorrect with regard to any warming effect. The atmosphere acts to block entering energy and cannot multiply it despite the assertions of the IPCC papers [that ignore the Laws of Thermodynamics, especially the first law. Abundant sources are available everywhere.]. This entire subject of global warming should be referred to as an hypothesis, as it is not recognized as accepted theory by all scientists. Science does not have a section for majority overrules minority. [Recall how there once was a majority who believed the earth was the center of the universe and the sun revolved around the earth.] Until there is clarification of this hard-to-analyze science, it will remain hypothetical. So, this Wikipedia article should say so. There are many faults with the IPCC that do not agree with accepted science, including the thermodynamics of gases. To be considered as an unbiased source and allow readers to learn all the evidence, Wikipedia should contain all opposing information in discussions involving hypothetical issues. Jgavinfl (talk) 14:24, 18 November 2014 (UTC)

Red information icon with gradient background.svg Not done for now: This sort of stuff is over my head but I can tell you that unless you provide links to some of these sources no changes will be made. Cannolis (talk) 16:37, 18 November 2014 (UTC)
Then how does Venus have a much higher surface temperature than Mercury? — Preceding unsigned comment added by 130.88.174.207 (talk) 06:02, 26 January 2015 (UTC)

The fact that Venus has higher surface temperatures than Mercury proves nothing. Mercury, Venus and Earth are three completely different planets with regard to their surface, composition, atmosphere, and many other factors that influence surface temperature. Bbigjohnson (talk) 12:12, 21 April 2015 (UTC)

— Preceding unsigned comment added by Bbigjohnson (talkcontribs) 10:17, 21 April 2015 (UTC) 
Now hang on, you asked us to accept "as evident" a comparison to planetary bodies without atmospheres, but you won't accept a comparison between Venus and Mercury because of the same basis for which you asked us to make a comparison? --OuroborosCobra (talk) 14:07, 21 April 2015 (UTC)

ref name="wood1909"

Replaced non working ref with working one. Fxmastermind (talk) 18:32, 20 April 2015 (UTC)

Is there anything wrong with the web page itself, as implied by your previous title? . dave souza, talk 21:44, 20 April 2015 (UTC)

I suspect it has been fixed. It's easy enough to check. http://www.wmconnolley.org.uk/sci/wood_rw.1909.html 01:09, 21 April 2015 (UTC) Fxmastermind (talk) 01:09, 21 April 2015 (UTC)

I found this note (from 2011) on a blog "Note that as of now, this is the maintained copy; the version on my website is now longer “live”." http://scienceblogs.com/stoat/2011/01/07/r-w-wood-note-on-the-theory-of/ Not sure what it means, but the link is working again, so it's all good. Fxmastermind (talk) 01:24, 21 April 2015 (UTC)

Sorry about that :-). I noticed your edit, and checked, and you were right, it was broken. I contacted my web hosting people and they fixed it. You're right about the blog post, though: in my mind, that is now the "official" version, whatever that means William M. Connolley (talk) 06:43, 21 April 2015 (UTC)

It's a good thing we have your blog, or there would be no source of that information about Wood and the experiments. Fxmastermind (talk) 14:24, 21 April 2015 (UTC)

Semi-protected edit request on 23 April 2015

In section 3 or "Greenhouse gases" under the list of greenhouse gases and above the last statement before the next section, additional information would increase the section's substantive value by explanations as to how the listed greenhouse gases contribute to global warming. The following is that additional information.

A study conducted in 2014 by scientists of the University of Miami Rosenstiel School of Marine and Atmospheric Science concludes that water vapor is a major factor in global warming. Human activity, which includes the burning of fossil fuels, accelerate the evaporation process. Higher concentrations of water vapor capture more heat and promote higher temperatures in the upper troposphere.

The excessive Carbon Dioxide found lingering in the atmosphere is due to burning of various fossil fuels that is caused by the burning of coal and use of electricity.

Methane in terms of the greenhouse effect derives from industrial facilities that process oil and or gasoline. Other contributors include farms and agricultural sites that harbor livestock that naturally emit methane and manure that does so as well.

Most ozone gases reside specifically within the stratosphere and are created by short-wave ultraviolet rays and airborne x-rays sparking reactions with oxygen. Doubledongdylan (talk) 03:43, 23 April 2015 (UTC)

I think you're referring to http://www.sciencedaily.com/releases/2014/07/140728153933.htm. I don't think we should make this request William M. Connolley (talk) 06:26, 23 April 2015 (UTC)

The last thing we want on Wikipedia is "additional information that would increase the section's substantive value". Fxmastermind (talk) 14:28, 23 April 2015 (UTC)

Proposed update to Fifth Assessment Report

In the section "Role in climate change", the third sentence reads "According to the latest Assessment Report from the Intergovernmental Panel on Climate Change, "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations".[24]" By now (November 2015), the "latest Assessment Report from the Intergovernmental Panel on Climate Change" is the Fifth Assessment Report, and it is even more explicit on the cause of the observed warming. The Summary for Policy Makers, number SPM 1.2, reads: "Their effects [carbon dioxide, methane and nitrous oxide], together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century."

(Source: IPCC, 2014: "Climate Change 2014. Synthesis Report. Summary for Policymakers", p. 4. IPCC, Geneva, Switzerland; https://www.ipcc.ch/pdf/assessment-report/ar5/syr/AR5_SYR_FINAL_SPM.pdf)

Please consider updating the pertaining sentence. CStreiss (talk) 10:34, 10 November 2015 (UTC)

Done crandles (talk) 11:28, 11 November 2015 (UTC)

more CO2 causes global cooling?

WP:NOTAFORUM. No reliable sources proposed on which to base article improvment.
The following discussion has been closed. Please do not modify it.

There is a good point made on the climate change forum.

http://www.climate-debate.com/forum/uh-oh-more-co2-causes-global-cooling--d6-e1037.php

216.165.213.215 (talk) 19:15, 16 January 2016 (UTC)

I'm not sure what your point is. The link is obviously not a WP:RS. Its text, The Sun beams UV, visible light, mid range IR at Earth. More CO2, more incoming mid range IR is blocked out. Earth's surface becomes cooler, is wrong. There's not much incoming energy in the IR, so very little is "blocked out", and anyway its not "blocked out" its absorbed by CO2. If you can point to any RS taking this seriously that would be a different matter William M. Connolley (talk) 19:21, 16 January 2016 (UTC)
See not even wrong (although this is a better explanation of the principle). Shock Brigade Harvester Boris (talk) 19:32, 16 January 2016 (UTC)
According to wiki, incoming sunlight is comprised of IR, UV, visible light. It follows that Earth's surface would be cooled by increase in CO2, because half of absorbed CO2 is shot into space, so more CO2 results in less IR from the Sun reaching Earth's surface. https://en.wikipedia.org/wiki/Sunlight— Preceding unsigned comment added by 216.165.213.215 (talkcontribs)
No, that's wrong. If the only IR involved were the one from the sun, then you might have a point. But the sun radiates most of its energy in the visible light, while the Earth (which needs to re-radiate all the energy it gets from the sun, otherwise it would heat up) radiates primarily in the infrared. See Thermal radiation or Planck's law. So while the CO2 indeed absorbs and re-radiates some of the incoming infrared radiation from the sun, that is only a very small part of the total energy we get from the sun. On the other hand, it absorbs and re-radiates the same fraction of outgoing radiation from the surface of the Earth, which is a much larger fraction of the total energy radiated from the Earth. If you have a pump that splashes in 1l of water per second into your boat, put remove 10l per second, then blocking the pump will not cause your water level to sink. --Stephan Schulz (talk) 21:29, 16 January 2016 (UTC)
According to wiki, IR is most of sunlight's energy that gets to Earth's surface. Visible light is the second biggest component after IR. UV is the smallest component. https://en.wikipedia.org/wiki/Sunlight — Preceding unsigned comment added by 216.165.213.215 (talk) 22:05, 16 January 2016 (UTC)

Calculations using GH effect don't work for Venus

Emissivity of CO2 is about 0.19. To raise the Venus surface temperature from 732K to 737K each Venus daytime, radiation of well over 16,500W/m^2 would be required. To emit such, the atmosphere would have to be over 1,100K which it obviously cannot be. Hence the radiative forcing greenhouse conjecture is false. Back radiation on Earth also cannot heat the warmer surface as the temperature is rising each morning. The solar radiation of 168W/m^2 reaching the surface is equivalent to that from a close blackbody at 233K, so no radiation calculations can explain Earth's surface temperature either. The temperature is determined by downward free (also called natural) convective heat transfer (also including thermal diffusion) by molecular collision which is increasing entropy as the Second Law of Thermodynamics says will happen. Peer reviewed documentation is only available in book form and in an on-line paper which will not be accepted by climatologists, but is correct. — Preceding unsigned comment added by 101.191.139.89 (talk) 22:03, 23 February 2016 (UTC)

I can't really make out your argument, but if you don't have reliable sources, there is no point to discuss the issue here. See WP:RS and WP:NOR. --Stephan Schulz (talk) 22:38, 23 February 2016 (UTC)

By my count there are actually not one but three arguments here.

  1. The first four sentences allegedly falsify the CO2 GHE for Venus based on a claimed CO2 emissivity of 0.19.
  2. Sentences five and six do so for Earth but via an ostensibly different argument based on diurnal variations in the boundary layer.
  3. The seventh sentence instead attributes the surface temperature of any planet, Venus or Earth, to a novel but incoherently described effect that as presented here makes no physical sense and therefore can safely be ignored.

I believe arguments 1 and 2 refuting the CO2 GHE are worth looking at in some detail because understanding them may help improve the article by making it harder to commit such fallacies.

Argument 1 falsely assumes emissivity of CO2 has a single value, 0.19, when in fact it can be anything from zero to 0.31 depending in a surprisingly subtle way on both optical thickness and temperature [Hottel 1954, Lapp 1960, Leckner 1972, Alberti et al 2015]. However that's not a problem for argument 1, which if sound would have worked for any value of CO2 emissivity substantially below 1. (The temperature and pressure at the surface of Venus make the CO2 emissivity there very close to 0.3.)

The problem common to both 1 and 2 is that neither one soundly refutes the GHE because both arguments misrepresent the role of downward longwave radiation, DLR, as the direct cause of the elevated surface temperature.

It cannot be the cause simply because the atmosphere is colder than the surface, and any such direct attribution would violate the Second Law of Thermodynamics.

The direct role of varying greenhouse gases is instead to determine the varying Effective Radiation Level (ERL), typically at some elevation well above the surface. When the Earth is in thermal equilibrium with the Sun, the temperature at the ERL must stabilize at about 254 K. This temperature is maintained homeostatically by the Planck feedback, which is negative. The environmental lapse rate (ELR) from there down to the surface, namely 7.8 K/km on Venus and 6.5 K/km on Earth, then determines the temperature of the atmosphere from the ERL all the way down to the surface, as a strikingly linear function of elevation.

Increasing greenhouse gases raises the ERL, thereby lengthening the path from it to the surface. Since neither the lapse rate nor the ERL temperature depends in any significant way on the elevation of the ERL, raising the ERL must therefore raise the temperature all along the path including at the surface.

That is the greenhouse effect.

This is essentially the mechanism on which the analysis of Venus's atmosphere is based in the 1998 book "The Planet Venus" by Marov and Grinspoon, albeit without the explicit concepts of Planck feedback and ERL. Any such analysis in terms of "back radiation" would have been impossible, not because radiation from the atmosphere of Venus does not exist (it is about 16.5 kW/m2 within a few dozen meters of the surface, in all directions) but because it is a side effect of the mechanism of surface heating of Venus, not a cause.

The surface of Venus is furthermore a thermal regime in which the Arrhenius logarithmic law fails very badly. This is not so on Earth because the partial pressure of CO2 at the surface is currently at around 63 Pa, up about 45% from its preindustrial level. At that low level many absorption lines remain "in the wings" as Pierrehumbert puts it, and new lines enter the arena linearly with the logarithm of the CO2 partial pressure.

On Venus the partial pressure of CO2 is currently 9.2 MPa, 150,000 times greater than on Earth, and there is no evidence that it is changing at remotely like the current rate on Earth. Unlike the ERL-lapse rate account, which works equally well on both Venus and Earth, this huge difference in CO2 surface partial pressures stresses the Arrhenius law far beyond its breaking point. On Venus the law as a function of partial pressure can be expected to be linear instead of logarithmic.

The Planck feedback and the ERL aren't exact concepts either. However as "little white lies" intended to make the GHE more understandable they do a much better job than the back-radiation account.

I believe the article could be greatly improved by doing a better job of explaining all this. As the current account of the effect is fundamentally predicated on back radiation it would have to be rewritten pretty much from scratch. As usual with Wikipedia the obstacle there would be finding editors willing to put in the necessary effort while fighting off the conservative elements resisting changes to Wikipedia articles, which across the board has become an order of magnitude worse today than a decade ago. Vaughan Pratt (talk) 07:59, 29 March 2016 (UTC)

In order to improve the article in this way, we would need a very good source that makes exactly the point you're trying to argue above. I don't see any link to such a text. --Nigelj (talk) 08:39, 29 March 2016 (UTC)
How about the IPCC Report? The article here claims that the "fundamental mechanism" of the GHE is warming of the surface by downward radiation, but the Report's definition says nothing of the kind. It says "The net amount emitted to space is normally less than would have been emitted in the absence of these absorbers because of the decline of temperature with altitude in the troposphere and the consequent weakening of emission. An increase in the concentration of greenhouse gases increases the magnitude of this effect; the difference is sometimes called the enhanced greenhouse effect. The change in a greenhouse gas concentration because of anthropogenic emissions contributes to an instantaneous radiative forcing. Surface temperature and troposphere warm in response to this forcing, gradually restoring the radiative balance at the top of the atmosphere."
This definition/explanation of the GHE is exactly correct. In particular radiative forcing is not the same thing as DLR, but rather the amount by which radiation to space decreases. Modern accounts of the GHE typically include the mechanism by which temperature declines with altitude, namely adiabatic cooling; presumably the Report was trying to keep the definition as short as possible and didn't find it necessary to include that mechanism. Googling for "effective radiation level" (in quotes) returns over 8000 results; it's the planetary counterpart of the photosphere of a star. Vaughan Pratt (talk) 19:25, 29 March 2016 (UTC)

I'm willing to bet a case of beer that the original poster for this thread is banned user Doug Cotton. Any takers? Shock Brigade Harvester Boris (talk) 11:59, 29 March 2016 (UTC)

I can confirm that you are correct William M. Connolley (talk) 15:57, 29 March 2016 (UTC)

Earliest claim that the greenhouse effect is a misnomer?

The article gives 1901 (Ekholm, [10]) for the date of introduction of the term "greenhouse effect", but 1992 (Oort et al, [37]) as the source of the claim that the term is a misnomer.

Certainly Wood (1909) did not claim it was a misnomer, quite the opposite in fact. He argued that greenhouses operate by "the prevention of the escape of the warm air", and inferred by analogy with how greenhouses work that "the heat received is thus stored up in the atmosphere, remaining there on account of the very low radiating power of a gas". He could only have considered "greenhouse effect" to be a misnomer if he believed that, unlike greenhouses, trapping radiation could significantly warm the Earth's surface. Instead he claimed the opposite by the analogy with greenhouses, which he did not dispute.

Did it really take 91 years (from 1901 to 1992) for it to dawn on someone that if trapping radiation did not warm greenhouses but did warm Earth's surface, contrary to Wood, then the term "greenhouse effect" must be a misnomer?

When I took honours physics in the 1960s we were taught that the greenhouse effect worked by analogy with greenhouses, with no mention of any controversy, suggesting a date between the 1960s and 1992 for when it first occurred to anyone to point out that it was a misnomer. But even in that case there is still a remarkable six or more decade gap before anyone noticed this very elementary inference, during which quantum mechanics developed from Planck's Law all the way to the Bell inequalities.

There is a different, trivially simple, explanation: the glass serves not to warm the interior of the greenhouse but merely to insulate it from the exterior. One would therefore expect that if the thermal radiation outside a greenhouse were higher than inside, the glass would keep the interior cool, not warm, the way a thermos flask keeps iced tea cool. Conversely if the outside were colder, e.g. the 2.7 K radiation of outer space that Earth sits in, the glass would keep it warmer, the way a thermos flask keeps hot coffee warm. I would be very interested in an explanation of how Wood's experiment disproves the latter effect.

For a suitable source, Abbot's July 1909 critique of Wood's experiment explains quantitatively how Wood's experiment doesn't disprove it, by analyzing the expected influence of Downward Longwave Radiation (DLR) from the atmosphere, a concept Wood seemed completely unaware of. This should not be so surprising given that Wood's expertise was in experimental optics while Abbot's was in astrophysics (Abbot was then the Director of the Smithsonian Astrophysical Observatory). Vaughan Pratt (talk) 06:24, 25 April 2016 (UTC)

Forgot to give the link to Abbot's article, which was archived in Archive 4 of this talk page, sorry about that. Vaughan Pratt (talk) 06:27, 26 April 2016 (UTC)

Sentence lacks a verb

This sentence, "In the Solar System, there also greenhouse effects on Mars, Venus, and Titan. " needs a verb, apparently "are," after "there." 73.69.4.249 (talk) 10:26, 9 December 2016 (UTC)

 Done Thanks, Gap9551 (talk) 16:03, 9 December 2016 (UTC)

Semi-protected edit request on 9 January 2017

In the third paragraph it is not clear that he the radiation coming from the surface of the earth is as a result of absorbed energy from the Sun.

Current paragraph: On Earth, the atmosphere is warmed by absorption of infrared thermal radiation from the underlying surface, absorption of shorter wavelength radiant energy from the sun, and convective heat fluxes from the surface. Greenhouse gases in the atmosphere radiate energy, some of which is directed to the surface and lower atmosphere. The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect.[3]

Proposed paragraph: On Earth, the atmosphere is warmed by absorption of infrared thermal radiation from solar energy heating the underlying surface, absorption of shorter wavelength radiant energy from the sun, and convective heat fluxes from the surface. Greenhouse gases in the atmosphere radiate energy, some of which is directed to the surface and lower atmosphere. The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect.[3] Franklima260 (talk) 02:05, 9 January 2017 (UTC)

Done, not in this exact wording though. Laurdecl talk 03:51, 10 January 2017 (UTC)
User:Franklima260 Did you mean to ask for WP:SEMI? There hasn;t been enough vandalism, and your paragraph following up contextually makes no sense. Perhaps this is an error?L3X1 (talk) 02:07, 9 January 2017 (UTC)
@L3X1: This page is semi-protected... Laurdecl talk 03:51, 10 January 2017 (UTC)
@Laurdecl: OK…did you just semi protect it? Or has it been SEMI for a while and I totally misunderstood whats going on here?L3X1 (talk) 13:01, 10 January 2017 (UTC)
@L3X1: It must be the latter since I'm not an admin. Far from it actually. The page has been semi-protected since 2010, the IP was requesting an edit... Laurdecl talk 13:07, 10 January 2017 (UTC)
@Laurdecl:Ah, now I understand, the IP was asking for a edit request, not a semi-protect. I feel like a fool for not getting that the first time through. L3X1 (talk) 14:15, 10 January 2017 (UTC)

Wrong information about solar irradiance in space on the image: "The green house effect.svg"

The solar irradiance, which is the irradiating power per area, on NASA's official page a quick search can show that the solar irradiance, at the surface of the Earth, is 1366 W/m2 maximum. So it's obvious that in space, that number can't possibly be inferior. — Preceding unsigned comment added by Goosneves (talkcontribs) 17:52, 2 June 2017 (UTC)

Earth has more surface area than sunlight intercepted area. Area of circle = Pi r^2 area of surface of sphere = 4 Pi r^2 so it is a factor of 4 different. NASA official page is showing 1366 W/m^2 which is per sunlight intercepted area. To get to irradience per m^2 of earths surface divide by 4. So 1366/4= 341 which is about what diagram is showing. crandles (talk) 18:23, 2 June 2017 (UTC)

Mechanism

The "mechanism" section of this article is too difficult to read. It presumes that readers are already thinking in technical terms and already possess quite a bit of technical knowledge. Everyday Wikipedia readers are likely to struggle or give up without finishing. Is anybody up for rewriting it? This page is too important to be inaccessible. 75.167.93.80 (talk) 21:41, 5 June 2017 (UTC)DG

I agree completely. It goes into way too much detail way too soon. Shock Brigade Harvester Boris (talk) 22:40, 5 June 2017 (UTC)
i also agree, so i did. but obviously User:William_M._Connolley like it as is was, didn't allow for change, and didn't the work himself to his satisfaction (only prevented others to do it to ). Maybe if someone else use my stuff he will act a litle more positively: feel free to look in history, before his revert on "don't play silly" ground (which i would translate "I Fuck you"), what can be used according to you. good luck, i guess you'll need it. Gem fr (talk) 09:05, 20 June 2017 (UTC)

History

This section should talk about how greenhouse effect affected Earth in the past geological eras. Instead it misleaddingly points to the history of climate change science — Preceding unsigned comment added by 2601:241:4200:1d10:9cb:27ee:46b6:f1fb (talkcontribs) April 21, 2016 (UTC)

you get a point, although i think both deserve a (different) section Gem fr (talk) 09:11, 20 June 2017 (UTC)