Talk:Greenhouse effect/Archive 6
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Please add Ice Age study
- Study of Ice Age Bolsters Carbon and Warming Link February 28, 2013 The New York Times
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.
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?
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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)
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 (talk • contribs) 13:45, 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)
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 (talk • contribs) 22:02, 28 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 (talk • contribs) 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 (talk • contribs) 20:52, 29 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 (talk • contribs) 22:36, 29 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)
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 (talk • contribs) 15:26, 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 (talk • contribs) 16:29, 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 (talk • contribs) 18:31, 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 (talk • contribs) 22:51, 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 (talk • contribs) 09:42, 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 (talk • contribs) 11:40, 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 (talk • contribs) 13:48, 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
- Care to say why it's nonsense? Considering the Science Museum says
- 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)
- 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)
- But Stephan, we don't actually explain that in the current article. It might be better to update the section to say something like:
- 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)
- 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 thanabout 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
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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)
Greenhouse Effect
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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)
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Heat transfer
Aded lede to heat transfer, here. Prokaryotes (talk) 19:27, 6 April 2014 (UTC)
Cosmic Microwave Background – Proposed Edit to this Article.
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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)
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 (talk • contribs) 19:41, 7 May 2014
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)
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)
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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)
- I think he might be talking about Greenhouse effect#Real greenhouses William M. Connolley (talk) 19:20, 13 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
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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)
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 (talk • contribs) 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
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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)
more CO2 causes global cooling?
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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)
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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.
- The first four sentences allegedly falsify the CO2 GHE for Venus based on a claimed CO2 emissivity of 0.19.
- Sentences five and six do so for Earth but via an ostensibly different argument based on diurnal variations in the boundary layer.
- 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)
Semi-protected edit request on 9 January 2017
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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: This page is semi-protected... Laurdecl talk 03:51, 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 (talk • contribs) 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 (talk • contribs) April 21, 2016 (UTC)
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I cannot believe I have to justify my deeds to a vandal, but the fact is, i have to. |
The source (IPCC) says "greenhouse gases trap heat within the surface-troposphere system. This is called the greenhouse effect." and "thermal radiation emitted by the land and ocean is absorbed by the atmosphere, including clouds, and reradiated back to Earth. This is called the greenhouse effect" (which is just another way to say exactly the same: greenhouse effect is about the loop between thermal radiation from the surface and part of it that atmosphere send back after having absorbed it. Note that greenhouse effect is NOT about the whole radiation from atmosphere to surface; even without greenhouse effect, atmosphere gets some energy by many other process and radiates part of it back to surface
The previous version of the article said "the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without its atmosphere.", which is wrong and wrong and wrong
- wrong because the whole radiation from a planet's atmosphere do not belong to greenhouse effect
- wrong because the atmosphere, being colder that surface, cannot warm it
- wrong because nowhere in the source you'll find such nonsense, you just cannot attribute the wrong statement to a source that do not endorse it (for a reason: it is physically absurd)
I corrected it, also adding some matters like optical depth, and substracting irrelevant details that belongs to greenhouse gas, not greenhouse effect (unless we merge thess articles, which i don't promote). User:William_M._Connolley reverted, which is rude, with a rude comment, and no explanation. Well, good faith assumption, and everybody can make mistakes and stubbornly stick to them. I corrected again, and talked on his page.
And he again reverted, again without explanation (i don't count "better before, I think" as an explanation, neither is the comment he made in reply on his talk page), which is just a conflict building in violation of WP rules.
Warning: we are past the vandalism point. Gem fr (talk) 10:30, 21 June 2017 (UTC) disclaimer: i am confident you can make it even better (even the vandal, provided he first learns to behave, to attributes to sources what they indeeed say, etc.). Provided you don't just revert, and do some actual work. Gem fr (talk) 10:30, 21 June 2017 (UTC)
- William M. Connolley passed by, and just collapsed a so-called incivility (well, that's ok for me).
- since he did had some activity meanwhile, i guess he just has nothing to answer to me.
- Does anyone object to us moving on, that is, to restore the article in my last form (from which it can then be edited again, as per my last previous comment)? Gem fr (talk) 09:04, 22 June 2017 (UTC)
- You write an awful lot to show umbrage at a mild description of 'silly' and start throwing around accusations of vandalism and describing silly as equivalent of swearing does you no credit. Would it be any wonder if people concluded you were writing lots of edits to an article that has evolved through lots of different editors reaching consensus and one editors version was not an improvement. Having said this, perhaps if the discussion turned to whether optical depth needed to be introduced so early and it was agreed that it should then maybe there could be some improvement to the article. Personally I doubt it needs to be introduced so early. So generally I think better as it is than with all of your edits. crandles (talk) 10:10, 22 June 2017 (UTC)
- Excuse me to take umbrage of seeing the article reverted to a version containing plainly wrong sillyness, with no explanation, accused of playing silly game, not answered when i ask why, etc. I guess you are so wise you wouldn't had failed to the fault. Following the group and preventing its disbanding is so much more important that to fix the content to make it encyclopedic, we should really frown upon the guys that begins shouting "EH, GUYS, there is someone doing it wrong" when ignored (irony/sarcasm inside, no pun intended).
- I don't care for credit, and you shouldn't either. All what we do is under CC, made under pseudonym, and I easily remember very good contribution from otherwise very despicable, bad mannered and bad tempered people.
- There is so much "consensus" that the article is semi-protected, subject to special discretionary sanctions, and its history shows countless editorial revert (not just restoration after childish vandalism) and edit war; already staring William M. Connolley, btw, i now observe: this guy should had be policed long ago, but, whatever, who knows, he may have some qualities that make up, pretty much the way rose flowers protect their prickles (he didn't showed them to me, still)...
- and, there may be "lots of different editors", but the fact is, the last of them put the article from a state (with no less consensus, AFAIK) where it accurately reproduce the definition of source IPCC, to current state where the source has been conserved but the definition altered in a nonsensical way. Well, good faith for sure, but, what the heck? Good faith is not trustworthiness, but i guess "lots of different editors" just didn't notice, or they would had protested, since they had left the article in a correct state.
- Whatever the cause (eg: good faith assumption, so you don't think that some editor twisted the definition to something very different (and wrong) from conserved source), your argumentum ad populum proves to be bandwagoning).
- and I checked very few things, so, excuse me to assume that "lots of different editors" did the same as i did (that is: didn't check anymore than i did; I am no better than they are and they are no better than i am), meaning any number of reference may tell things different or even opposed to what the article make them endorse. Chilling.
- On the other hand, a few browsing the archive section shows that very sound material, agreed by everyone, somehow didn't made into into the article while needed, or even were derailed (as the definition was).
- optical depth was just not mentioned, i added it, and you seem to agree it had to be done. I don't object if you think i did too early (it indeed is quite technical)
- Bottom line: try again, none of your argument to "think better as it is than with all of [my] edits" stand.
- But then again, this is not a matter of "as it is" Vs "with all my edits". You, as any other, are free to make it better, started from whatever version suits you more. If you don't, you just make us lose our time.
- Gem fr (talk) 14:36, 22 June 2017 (UTC)
- Elsewhere you asked me for advice and I replied "make effective use of WP:Dispute resolution". This lengthy post is not that. NewsAndEventsGuy (talk) 16:05, 22 June 2017 (UTC)
- This post may be full of flaws, but it does exist. It maybe not be "effective", but it manifests my "use of WP:Dispute resolution". Obviously the other party don't even try, does it? Gem fr (talk) 10:34, 23 June 2017 (UTC)
- Elsewhere you asked me for advice and I replied "make effective use of WP:Dispute resolution". This lengthy post is not that. NewsAndEventsGuy (talk) 16:05, 22 June 2017 (UTC)
- You write an awful lot to show umbrage at a mild description of 'silly' and start throwing around accusations of vandalism and describing silly as equivalent of swearing does you no credit. Would it be any wonder if people concluded you were writing lots of edits to an article that has evolved through lots of different editors reaching consensus and one editors version was not an improvement. Having said this, perhaps if the discussion turned to whether optical depth needed to be introduced so early and it was agreed that it should then maybe there could be some improvement to the article. Personally I doubt it needs to be introduced so early. So generally I think better as it is than with all of your edits. crandles (talk) 10:10, 22 June 2017 (UTC)
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NPOV violation
This article claims that "heating in the usual greenhouse is due to the reduction of convection,[32] while the greenhouse effect works by preventing absorbed heat from leaving the structure through radiative transfer." I submit that this is a violation of NPOV.
The theory that insolation entering a container via glass heats the interior by trapping thermal radiation was first demonstrated experimentally in 1767 by Horace de Saussure. The portion of the IPCC report cited as reference [14] in the present article bears this out as follows.
"The ability to generate an artificial warming of the Earth’s surface was demonstrated in simple greenhouse experiments such as Horace Benedict de Saussure’s experiments in the 1760s using a ‘heliothermometer’ (panes of glass covering a thermometer in a darkened box) to provide an early analogy to the greenhouse effect."
Although this was the first such scientific experiment, de Saussure himself motivated it as follows. "it is a known fact, and a fact that has probably been known for a long time, that a room, a carriage, or any other place is hotter when the rays of the sun pass through glass." This directly contradicts the present article.
Quoting the same source, "De Saussure first built a miniature greenhouse five walls thick. He constructed it from five square boxes of glass, decreasing in size from 12 in. on a side by 6 in. high to 4 in. on a side by 2 in. high. The bases of the boxes were cut out so the five boxes could be stacked one inside the other atop a black wooden table. After exposing the apparatus to the Sun for several hours, and rotating the model so that solar rays always struck the glass covers of the boxes perpendicularly, de Saussure measured the temperature inside. The outermost box was the coolest, and the temperature increased in each succeeding smaller box. The bottom of the innermost box registered the highest temperature—189.5 °F." (87.5 °C).
[It should be clear that if the glass covers were only preventing convection then the five interiors of the boxes would equilibrate to the same temperature as one box with one pane of glass, as additional panes cannot further decrease convection.]
The next such experiment was conducted more than 120 years later, described as follows by Charles Greely Abbot in an article published in July 1909.
"On November 4, 1897, the thermometer recorded 118°C within a circular wooden box 50 centimetres in diameter, 10 centimetres deep, insulated in feathers, covered with three superposed and separated sheets of plate glass and exposed normally to the sun rays in the yard of the Astrophysical Observatory at Washington. The temperature outside was 16°C."
Abbot's article rebuts the experiment that the present article cites as reference [6], namely a one-and-a-half-page article published in February 1909 about an experiment with two boxes with respectively glass and salt lids which both reached an interior temperature of about 60 °C, almost 60 degrees cooler than the experiment conducted at the Smithsonian Astrophysical Observatory a decade earlier. [Since a salt window traps no thermal radiation there is no way a box with three salt windows could reach 118°C (244 °F) purely by blocking convection.] This six-paragraph article contains not a single calculation, nor a single reference to or acknowledgment of any prior experiments supporting the opposing theory, and concludes, surely redundantly, "I do not pretend to have gone very deeply into the matter".
The next occasion on which this matter came up for debate was in the 1970s as reported a decade later by Professor Craig Bohren, who pointed out that ""the atmospheric science community seems to be divided into two groups". Bohren does not takes sides on the question, and it is pretty clear from his discussion of the two groups that Wikipedia is in violation of NPOV when it dogmatically takes one side on the question with no mention whatsoever of the extensive support for the other side since 1767.
Wikipedia has stacked the deck here by citing a single almost completely undocumented experiment while refusing to cite far more professionally documented experiments supporting the other side, even after I pointed them out to the owners of this article back in 2010. Instead they simply deleted my edits. To strengthen their case the editors added the following bit of OR. "Outside, the warm air near the surface rises and mixes with cooler air aloft, keeping the temperature lower than inside, where the air continues to heat up because it is confined within the greenhouse. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature will drop considerably." Their response to my request for a citation for their theory and gedankenexperiment was simply to delete my request. Vaughan Pratt (talk) 01:06, 27 December 2017 (UTC)
Temperature conversion problem
There's some confusion in the temperature unit conversions in the Mechanism section. One sentence reads, "The surface temperature of this hypothetical planet is 33 °C (91 °F) below Earth's actual surface temperature...". A 33°C difference is a 59.4°F difference. It's a mistake to convert a temperature change in Celsius to an absolute temperature in Fahrenheit (the 32°F offset cancels when comparing two temperatures).
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Edit: Added tag to try to get permission and/or eyes on this. Need to change "planet is 33 °C (91 °F) below" to "planet is 33 °C (59 °F) below". Nubicles (talk) 22:43, 29 October 2018 (UTC)
Done. And very good catch! –Deacon Vorbis (carbon • videos) 04:02, 30 October 2018 (UTC)- Argh. Thanks. We went through a spell on various climate-related articles where random people would come in and "correct" the F equivalent of C temperature changes to the F temperature corresponding to the C temperature (not change), then we'd have to undo them -- often getting into tedious arguments because they knew they were right... Looks like we missed one. Shock Brigade Harvester Boris (talk) 04:08, 30 October 2018 (UTC)
Real Greenhouses and Real Atmospheres
Convection and conduction can only transfer heat from a hotter place to a colder one, so by definition, since a greenhouse is hotter on the inside than it is on the outside, heat will always flow from the inside to the outside, cooling it off instead of heating it up -- the exact opposite of what the greenhouse effect is supposed to do. Long-wave radiation given off by the warm Earth is absorbed by water vapor, clouds, and carbon dioxide in the atmosphere. The trapping of ground radiation (heat) by the Earth's atmosphere is called the greenhouse effect. In a greenhouse, glass takes the place of the water vapor and carbon dioxide. The sun's short-wave rays pass through the glass roof, but the glass will not permit the long waves to escape. As an example of the atmosphere's greenhouse effect, the temperature does not drop as much on a cloudy night as it does on a clear night. — Preceding unsigned comment added by 72.54.91.26 (talk) 17:26, 17 December 2018 (UTC)
In other words, it is physically impossible for real greenhouses warm up due to convection or conduction, they can only warm up due to radiation ("by allowing sunlight to warm surfaces"). Warming up is the greenhouse effect; cooling down is not.
So whether it is a real greenhouse or a real atmosphere, the only way for energy to get into either one of them is via radiation, therefore the ONLY role convection or conduction can ever play in the greenhouse effect or in real greenhouses, is by counteracting the greenhouse effect by cooling them off.
This is all elementary thermodynamics and explains why radiation is considered the primary factor for creating a greenhouse effect (the warming effect), and not the other way around, i.e. -- by limiting convection or conduction (limiting the cooling effect).
Case in point, Standford engineers invented a coating to help cool buildings, and the way in which this coating worked was presented in a peer reviewed science journal using a miniature real greenhouse, i.e. -- a "rooftop apparatus" in which convection and conduction were minimized using polystyrene and an enclosed container. This setup was very much like the Wood's Experiment, only the Stanford experiment was properly conducted under rigorous scientific conditions and clearly eliminated any unknown variables that the Wood's experiment did not. The thing to note about this peer reviewed scientific experiment is that without any convection or conduction, THE TEMPERATURE NOT ONLY DID NOT RISE, IT EVEN COOLED TEN DEGREES BELOW AMBIENT. This proves that limiting convection does cannot create or cause the greenhouse effect, but that convection is just merely undesirable effect, detrimental to the greenhouse effect, with RADIATION BEING THE PRIMARY CAUSE OF THE GREENHOUSE EFFECT, both in real greenhouses and in the real atmospheres.
Just like a perfectly built real greenhouse, the real Earth cannot gain or lose heat by convection or conduction, it can only gain or lose heat by radiation. An imperfectly or improperly built real greenhouse can lose excessive heat by way convection or conduction, but that only counteracts the greenhouse effect, it does not contribute to it in any way, shape, or form.
References:
[1] Heat Transfer. Wikipedia. https://en.wikipedia.org/wiki/Heat_transfer
[2] Second Law of Thermodynamics. "Heat always flows spontaneously from hotter to colder bodies, and never the reverse, unless external work is performed on the system". Wikipedia, https://en.wikipedia.org/wiki/Second_law_of_thermodynamics
[3] Aswath Raman et al (2014). Passive radiative cooling below ambient air temperature under direct sunlight. NATURE, VOL 515, 27 NOV 2014, http://www.nature.com/nature/journal/v515/n7528/full/nature13883.html
writing
The section on the mechanism does a particularly bad job at explaining how it works. Completely incoherent writing style. Does a poor job at informing the public on such an important topic. — Preceding unsigned comment added by Chrimas1 (talk • contribs) 12:33, 5 March 2019 (UTC)
- see WP:SOFIXIT NewsAndEventsGuy (talk) 12:56, 5 March 2019 (UTC)
Basic Error in Attribution of Source of Back Radiation
The statement in the article
″The atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for "window" bands), and most heat loss from the surface is by sensible heat and latent heat transport. Radiative energy losses become increasingly important higher in the atmosphere, largely because of the decreasing concentration of water vapor, an important greenhouse gas.″
This makes a common, but incorrect assumption that the thermal energy from radiative absorption, sensible heat and latent heat can be separated once they are absorbed. In fact thermal emission results from the temperature of the part of the atmosphere that emits and this is a function of the total amount of thermal energy in the emitting volume. An analogy is that if there are three sources of black jelly beans being put in a jar, and one of them pulls beans out, how can you tell what the original source was.
There is an interesting point buried in the current statement, which is low in the atmosphere the amount of thermal energy from surface radiation is very high. This decreases with altitude, but at the same time the amount of thermal radiation received from greenhouse molecules increases (but so does that from sensible and latent heat, the later being very altitude/temperature dependent)
Untangling this is going to require some careful wordsmithing
Joshua Halpern (talk) 16:27, 4 April 2019 (UTC)
- Ok, please take care to ensure that any changes you propose are verifiable from cited reliable sources. Thanks, . dave souza, talk 16:55, 4 April 2019 (UTC)
Semi-protected edit request on 10 April 2019
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On the third line of the article the phrase is: "If a planet's atmosphere contains radiatively active gases (i.e., greenhouse gases) they will radiate energy in all directions."
The word "radiatively" was misspelled and it should be "radioactively". Viniciusnmelo (talk) 09:59, 10 April 2019 (UTC)
- Thanks, this points up wording which isn't very explanatory. Radiatively is used to mean the property of greenhouse gases; that they absorb and emit radiant energy within the thermal infrared range. Think that could be phased more informatively. However, it's not the same as radioactive. . . dave souza, talk 10:22, 10 April 2019 (UTC)
Semi-protected edit request on 20 May 2019
An ideal thermally conductive blackbody at the same distance from the Sun as Earth would have a temperature of about 5.3 °C (41.5 °F). However, because Earth reflects about 30%[12][13] 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 (0 °F).[14][15] The surface temperature of this hypothetical planet is 33 °C (59 °F) below Earth's actual surface temperature of approximately 14 °C (57 °F).[16]
should read, due to incorrect conversion.
An ideal thermally conductive blackbody at the same distance from the Sun as Earth would have a temperature of about 5.3 °C (41.5 °F). However, because Earth reflects about 30%[12][13] 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 (0 °F).[14][15] The surface temperature of this hypothetical planet is 15 °C (59 °F) above Earth's actual surface temperature of approximately 14 °C (57 °F).[16]
2600:8804:4900:6A:6C92:7828:5960:AD41 (talk) 00:34, 21 May 2019 (UTC)
Semi-protected edit request on 2 August 2019
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Remove Link to IPCC Website in source 4 -> Link no longer valid (Error 404) 2.205.72.152 (talk) 13:06, 2 August 2019 (UTC)
- Done I have replaced it with a working link. Gulumeemee (talk) 03:41, 5 August 2019 (UTC)
Mechanism section is incomprehensible
This description is confusing and full of very obvious flaws it urgently needs to be rewritten entirely and protected. Here are some of those issues:
"The basic mechanism can be qualified in a number of ways, none of which affect the fundamental process." It's not at all clear what this even refers to and makes no sense in context?
"The atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for "window" bands), and most heat loss from the surface is by sensible heat and latent heat transport." What surface and what is "sensible heat"?
"It is more realistic to think of the greenhouse effect as applying to a layer in the mid-troposphere" More realistic than what? No Alternative explanation has been given thus far!
"The simple picture also assumes a steady state, but in the real world" What simple picture?
"Earth's surface, warmed to a temperature around 255 K" 255 Kelvin is -18.15 degrees Celsius. The surface of the earth is a lot warmer than that?
It almost seems like this section was written to be deliberately misleading. — Preceding unsigned comment added by Jpahlen (talk • contribs) 22:06, 8 October 2019 (UTC)
Bodies other than Earth edit needs
This section was, and still is in need of tender loving care. I stumbled upon the sentence about Titan, which was in bad shape but I've improved. Obviously, let's discuss if it could be further improved.
I was going to tackle the rest of this section but it's more than I can take on at this moment.
The first paragraph is about Venus. I see three facts, the first of which is uncited, second of which is a note that the referencing is circular, in the third of which is an article about Titan not Venus. that almost certainly means the conclusion ("The 'greenhouse effect' on Venus is particularly large for several reasons") is almost certainly not supported. It is plausible that fixing the three citation problems will solve that but editors need to address citations for each of the three facts and separately conclude that the overall conclusion is adequately supported.
The next sentence says: "Venus experienced a runaway greenhouse in the past, and we expect that Earth will in about 2 billion years as solar luminosity increases"
The first point is in the lead, and the second point is about earth which doesn't qualify as a body other than Earth.
As an additional point about the first paragraph and this sentence, we generally write the detailed discussion in the main part of the article, then summarize the main points in the lead. While I haven't looked closely at the lead it seems that the lead does a decent job of discussing Venus, while this section, not so much. Editor should look into whether the discussion in the lead belongs here with a summary in the lead.
The next sentence is about Mars. Describing the temperature is very cold is anthropomorphic and not encyclopedic. Furthermore the reference is to Wikipedia which is not an acceptable reference. The final sentence is very casual style, and should be improved.
I'm biased but I think the Titan sentence is now okay.
Stating that Pluto is "colder than would be expected" is too casual. Presumably the comparison is Pluto with an atmosphere versus Pluto without an atmosphere but this needs some work. (Yes, I see that is literally the title of the source, but that doesn't make it acceptable.)--S Philbrick(Talk) 21:47, 3 November 2019 (UTC)
- Reading the cite I see Pluto is nothing to do with the greenhouse effect so I deleted.Chidgk1 (talk) 18:57, 26 December 2019 (UTC)
I decided to remove the following paragraph:
In complete contrast, the mean temperature on Mars is -63 °C (-81 °F). This is despite having over 95% atmospheric CO2, almost the same as Venus’s atmosphere. Mars is further from the Sun than Earth but still receives about 44% of the Sun’s heat [approx 500 W/m2] when compared to Earth. The reason for its greenhouse effect being so much smaller is because the atmosphere is much thinner than the atmospheres on Earth and Venus.
Although the source uses the phrase "complete contrast", that's rather casual, and in the sentence it doesn't even identify what's being contrasted to do what. I realize that minor point could be cured but I see too many problems with this paragraph.
The next phrase states the mean temperature on Mars. So what? Presumably, the point of discussing the greenhouse effect is to talk about the actual temperature versus the expected temperature in the absence of the greenhouse effect. The sentence makes no hint about what the temperature would be without the greenhouse effect. Nor is it in the single source, so it's not as simple as pulling that into the sentence.
The next sentence may be factual but it doesn't come from the source. Perhaps it's intended to be a set up for a discussion of how the temperature on Mars compares to that on earth, but this paragraph doesn't go there.
The next sentence is true but it doesn't say very much. It asserts that the greenhouse effect is so much smaller because the atmosphere is thinner but doesn't state how much smaller it is, nor how much thinner the atmosphere is, nor the relationship between the thinness of the atmosphere and the impact on the greenhouse effect. In other words, it is stating a random fact tangentially related to the subject matter but doesn't tell you anything interesting.
I see value in discussing the greenhouse effect on Mars, but it isn't the case (in my opinion) that one could start with this paragraph and fix it up a little bit. It's pretty much a start over and do it right. Not having the energy to do that right now, I think it's better to just remove it until such time as someone wants to take this on.--S Philbrick(Talk) 23:12, 26 December 2019 (UTC)
Description of mechanism of global warming not accurate
The description of the mechanisms of the greenhouse effect in this article is not accurate. The actual mechanisms are described in these articles:
- http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/
- http://clivebest.com/blog/?p=1169
- https://earthscience.stackexchange.com/questions/18986/can-anyone-explain-the-real-reason-why-co-2-increases-global-temperatures-not
- Quite right, but try persuading this article's "Wikiguardians" of this. They won't let you change it (heaven knows I've tried hard enough myself). Jimmy Wales eventually stepped in a number of years ago and declared that one of them was an "expert" in the area and therefore he should be the arbiter on this.
- The fact is that as CO2 increases, DLR - ULR (the net downwards flux) actually decreases, both in theory (an easy calculation) and in practice (or the effect wouldn't exist). The article is quite correct in claiming that DLR increases with increasing CO2, but what this overlooks is that ULR increases even faster. Simply pointing an infrared thermometer upwards only gives half the story, you have to also point it downwards and average the difference over several years. The IPCC's definition of the greenhouse effect in the glossary of AR5 WG1 gets this right, this article gets it wrong. My own account of the greenhouse effect is summarized in the fifth image at http://clim8.stanford.edu/Images/ Vaughan Pratt (talk) 16:51, 18 April 2020 (UTC)
Eunice Foote
The work of Eunice Foote should be mentioned in this Wikipedia article.
https://www.chemistryworld.com/culture/eunice-foote-the-mother-of-climate-change/4011315.article — Preceding unsigned comment added by 173.228.119.8 (talk) 02:35, 24 April 2020 (UTC)
Semi-protected edit request on 13 May 2020
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Change "33C (57F)" to "33C (91F)". Gumbodumbo11 (talk) 22:30, 13 May 2020 (UTC)
- Not done: @Gumbodumbo: This appears to not be a direct conversion; but a difference (ex. 33 C is 91 F, but a difference of 33 C is only 59 F; and (since 1 C is 9/5 F, so 33 C = 59.4 F). Why anybody in their sane mind would use Fahrenheit in an article about a scientific topic (where the more usual units, across the globe, are either Celsius or Kelvin) eludes me, but there is no reason to change this particular bit. Thanks, RandomCanadian (talk | contribs) 22:58, 13 May 2020 (UTC)
New Greenhouse Effect Analysis
...snip...
See edit request below.
Semi-protected edit request on 29 January 2021
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Change "in the anti-greenhouse effect, the atmosphere keeps radiation out while letting thermal radiation out" to "in the anti-greenhouse effect, the atmosphere lets radiation out while not letting thermal radiation in" ..Tarun..Khardia.... (talk) 05:21, 29 January 2021 (UTC)
Not done. See anti-greenhouse effect. ◢ Ganbaruby! (Say hi!) 06:29, 29 January 2021 (UTC)
Semi-protected edit request on 28 October 2020
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A new book, "Air of Doubt" (ISBN: 979-8697917329) by Dr. Frank A Tinker, offers an argument against the existence of a Greenhouse Effect. It applies the Stefan-Boltzmann Equation to the 65mW/m^2 geothermal flux found over continental crust to resolve the 33K(C) temperature deficit when only solar flux is used. The argument is that steady-state flux, both solar and geothermal, requires the use of the superposition principle when analyzing the solution of the heat equation for the column of earth being heated. As such, the sum of the separate solutions (solar and geothermal) is 255K + 33K = 288K. Thus, Earth's global mean surface temperature is fully described by the solar and geothermal flux, leaving no room for a Greenhouse Effect.
For completeness, it appears that reference and argument should be included in this topic. Link: www.airofdoubt.com
[1] AoDFT (talk) 17:02, 28 October 2020 (UTC)
- Not done the book is WP:self-published, which makes it an unreliable source for the purposes of Wikipedia. The author is not an expert in climate science. Furthermore, it adheres to a WP:FRINGE perspective, which we typically don't cover in the scientific article. Not only does it denying climate science, it also contradicts general relativity and Kepler's laws, other well-established scientific fields. Femke Nijsse (talk) 17:39, 28 October 2020 (UTC)
″it also contradicts general relativity and Kepler's laws″
It does? Just how does it do that? Are you a reliable source? Damorbel (talk) 09:38, 20 February 2021 (UTC)
References
- ^ Tinker, F.A. (2020). Air of Doubt: Exposing the largest and most costly scientific error in history, ISBN: 979-8697917329.
Do aerosols "work differently" from greenhouse gasses?
@User:Femkemilene: Yes, it's true that aerosols work slightly differently from greenhouse gasses. However aerosols do contribute substantially to the greenhouse effect. In particular, radiatively active aerosols in a planet's atmosphere do also radiate energy in all directions. And, just as with GHGs, part of this radiation is directed towards the surface, thus warming it. Therefore the lead should rightly make reference to aerosols.--Pakbelang (talk) 00:57, 22 October 2021 (UTC)
- What source are you basing this on? I'm aware that clouds can function similarly to GHGs, but I'm not aware of any source that likens the radiative effects of aerosols to GHGs. The net effect of aerosols is to cool the surface. Femke (talk) 06:55, 22 October 2021 (UTC)
- User:Femkemilene Yes, the net effect of many aerosols is to cool the surface. The radiative effects of aerosols depend on their size.[1] For bigger aerosols, their radiative effects outweigh their albedo effects.--Pakbelang (talk) 06:45, 23 October 2021 (UTC)
References
- ^ Lacis, Andrew (1992). "Climate forcing by stratospheric aerosols".
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Edit Request for Fifth Paragraph in Introduction
The line "The greenhouse effect as an atmospheric mechanism functions through radiative heat loss while a traditional greenhouse as a built structure blocks convective heat loss.", while partially true, is misleading. Glass is also a reflector of infrared radiation. It is still true that the method of heat retainment radiatively is different, as atmospheric retainment is the result of absorption while with glass it would be reflection (mainly due to the different refractive index in each) (Also it does indeed depend on the type of glass.)
Sources:
[4] (Writer is PhD)
It's also important to note that "near-IR" wavelengths do in fact transmit through glass. But just as a reminder this infrared is only emitted when objects get up to 800°F/450°C. In no case does a greenhouse get that hot. Thus, glass absorption and reflection are primary mechanisms for heat retainment in actual greenhouses.
If necessary (given WP:BOLD), I can add the content myself, but given it's a valuable and potentially targeted article, I felt that I should post in the talk section before I do so. If there isn't a response within a day or two, I'll make the edit myself.
Ezra Kirkpatrick (talk) 16:57, 30 November 2021 (UTC)
- I'm not seeing a proposed edit; but you sound like you're wrong. See-also Greenhouse_effect#Real_greenhouses William M. Connolley (talk) 19:18, 30 November 2021 (UTC)
References
- ^ https://www.researchgate.net/figure/Infrared-reflection-spectra-of-silica-glass-plate-at-different-polarization-angles-The_fig4_234996569
- ^ https://www.sciencedirect.com/science/article/abs/pii/S0022309315301526
- ^ https://physics.stackexchange.com/questions/74638/transmittance-of-glass
- ^ https://climaterx.wordpress.com/2013/04/11/can-infrared-light-pass-through-glass/
- ^ https://edavies.me.uk/2014/08/ir-myth/
- ^ http://abyss.uoregon.edu/~js/glossary/infrared.html
The Greenhouse effect - in common language
All objects emit light that depends on their temperature (thermal radiation). This does not mean the visible light that comes from objects when sunlight falls on them or something like that, but light that depends on their temperature. The hotter the object, the more energetic the light. In ordinary objects this light is invisible, (is, for example, in the infrared region), but if the object is heated more, it begins to illuminate in the visible region (such as red-hot iron).
The sun warms the earth's surface and the earth radiates invisible light depending on its temperature in each place. In the atmosphere there are gases, for example greenhouse gases that "absorb" part of this light and then the molecules begin to rotate and vibrate more and with that it heats up. This is not completely different from what happens in a microwave oven. The microwave oven makes invisible light, which the oven produces in a certain way and the food in it absorbs this light, which causes the molecules in the food to rotate and with that it heats up.
When the earth radiates its invisible light, some of it would just go into space, but when more greenhouse gases are added, more of the heat is absorbed by the atmosphere and some of it is radiated back to the earth.
The problem is mainly fossil fuels, oil, gas and coal. When burned, the greenhouse gas carbon dioxide is formed. Someone may then ask if the man has not always been burning firewood and thereby producing carbon dioxide. Yes, that's right, but what happened then was that plants absorbed the carbon dioxide that was created by the fire, as well as water and sunlight, and produced from it oxygen and carbohydrates, in a process called photosynthesis, so this was a cycle in which the carbon dioxide formed by the fire of the firewood was occupied by other plants and the amount of carbon dioxide remained fairly constant in the atmosphere. When fossil fuels are burned, on the other hand, carbon is added to the carbon cycle and carbon dioxide in the atmosphere, causing increased greenhouse effect, whereas larger portion of the earth’s thermal radiation is absorbed by the atmosphere and some of it is radiated back to earth. It should be noted that part of the added carbon dioxide goes into the sea and causes ocean acidification.
Without the greenhouse effect it would not be habitable on earth, it would simply be too cold, but the increase in greenhouse gases could be causing rapid warming.
Gunnar Björgvinsson (talk) 11:03, 28 October 2021 (UTC)
- Hello Gunnar :). Talk pages on Wikipedia are meant to discuss ways to improve the corresponding article. Would you like to see specific changes in the article? Femke (talk) 11:06, 28 October 2021 (UTC)
- Hi Femkemilene. I would like my article to be a section in the main article. Is that possible? Gunnar Björgvinsson (talk) 12:31, 28 October 2021 (UTC)
- Unfortunately, it's not quite ready to be put in the article. I think you want the article to be easier to understand, right? That's an important goal, a lot of Wikipedia articles are a bit too difficult! However, adding duplicate information in a simpler tone is usually not the right way to do this. Instead, you can propose how the current text should be changed to be easier to understand. Importantly, you need reliable sources to support your text. Femke (talk) 12:53, 28 October 2021 (UTC)
Hi Femkemilene. Ok, I dont feel up to making proposes for changes, however I think the main article would be better if there was a section made for people who have zero knowledge in chemistry and physics, with simple explanations, however I will not do more, for now at least. Regards Gunnar Gunnar Björgvinsson (talk) 10:08, 1 November 2021 (UTC)
- Hi Gunnar, are you aware of this page: Greenhouse effect (Simple English)? Simple English Wikipedia is designed to be written using non-technical language in a summary format. It may be the kind of thing you had in mind.Pakbelang (talk) 03:33, 2 November 2021 (UTC)
Hi Femkemilene. Thanks for pointing this page out to me. 46.22.98.93 (talk) 10:25, 3 November 2021 (UTC) Hi Femkemilene Sorry I meant to address Pakbelang. Regards 46.22.98.93 (talk) 10:32, 3 November 2021 (UTC) Hi Pakbelang. Thanks for pointing this out to me. Regards 46.22.98.93 (talk) 10:32, 3 November 2021 (UTC)
@Gunnar Björgvinsson: or anyone - could you check the beginning (lead) of the article is right and improve further? Chidgk1 (talk) 19:13, 8 January 2022 (UTC)
- Alas, you have turned the lede into nonsense. Do you really think the GHE only works at night? William M. Connolley (talk) 20:52, 8 January 2022 (UTC)
- It was not mean to imply only at night - if it read like that I misworded it by misreading https://climatekids.nasa.gov/greenhouse-effect/ - I was only trying to do a quick fix to make the lede better than before as requested in the talk section below - I have no idea how quickly the heat leaves the planet's night side compared to the day side - if you have more time feel free to correct everything properly Chidgk1 (talk) 07:01, 9 January 2022 (UTC)
- Naughty NASA Climate Kids! As a non-expert, I've made a quick fix (tweaked) based on the remaining source, please find a better simple explanation. Cite 37 to FAQ 1.3 – AR4 WGI Chapter 1: Historical Overview of Climate Change Science attributed to Stephen Schneider looks pretty good, but surely there's a newer source? . . .dave souza, talk 20:07, 9 January 2022 (UTC)
- It was not mean to imply only at night - if it read like that I misworded it by misreading https://climatekids.nasa.gov/greenhouse-effect/ - I was only trying to do a quick fix to make the lede better than before as requested in the talk section below - I have no idea how quickly the heat leaves the planet's night side compared to the day side - if you have more time feel free to correct everything properly Chidgk1 (talk) 07:01, 9 January 2022 (UTC)
Mini-review of article in paper
This article was assessed in a paper by Dunn et al (2021). The paper is behind a paywall. It argues that
- The first paragraph is inaccurate. (I feel it's also ungrammatical)
- The rest of the lead suffers from ineffective explanation, both conceptual and procederal. Noticing more grammar errors.
- The body has not enough clear images, and suffers from ineffective procedural explanations.
Procedural explanations is typically not something you'd see much in an encyclopedia, but I do understand their feedback on the lede. Don't have time to tackle it in next x months, so if somebody else wants to have a go. Femke (talk) 18:16, 6 January 2022 (UTC)
- I replaced the first sentence. But I object on principle to paying to read the paper. It seems from the abstract that, although it is not much, their students do get some benefit from Wikipedia. So we should not have to pay to read the article in order to improve the articles to benefit their students further. They should make the article freely available in the hope Wikipedia editors will read it and take action thus benefiting their students. But I am too lazy at the moment to write to them and suggest that. Chidgk1 (talk) 15:36, 8 January 2022 (UTC)
- @Chidgk1: Paying to access articles is absurd, obviously, but there are other ways to access them. Emailing the authors is one option worth considering, and Wikipedia:WikiProject Resource Exchange/Resource Request is another.
There's another option, but obviously I'd never recommend a pirate site.Guettarda (talk) 16:08, 8 January 2022 (UTC)
- @Chidgk1: Paying to access articles is absurd, obviously, but there are other ways to access them. Emailing the authors is one option worth considering, and Wikipedia:WikiProject Resource Exchange/Resource Request is another.
- I replaced the first sentence. But I object on principle to paying to read the paper. It seems from the abstract that, although it is not much, their students do get some benefit from Wikipedia. So we should not have to pay to read the article in order to improve the articles to benefit their students further. They should make the article freely available in the hope Wikipedia editors will read it and take action thus benefiting their students. But I am too lazy at the moment to write to them and suggest that. Chidgk1 (talk) 15:36, 8 January 2022 (UTC)
There isn't more in the paper anyway (did not check all supplementary data) Femke (talk) 16:11, 8 January 2022 (UTC)
William M. Connolley It seems you think I made the lede worse - from "inaccurate" to "nonsense". The paper above did not actually say what was inaccurate about the previous lede so it was hard for me to amend. Maybe you can explain what was inaccurate about the previous lead - maybe it was something very specific which just needed a word or 2 changing? Thanks RCraig09 for your corrections. Chidgk1 (talk) 07:10, 9 January 2022 (UTC)
The first paragraph was only one sentence which read "The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere." It now reads "The greenhouse effect is the warming of the world due to greenhouse gases in the atmosphere trapping the Sun's heat." William M. Connolley - so has that solved the inaccuracy? Chidgk1 (talk) 17:28, 9 January 2022 (UTC)
- not quite. The GHE is present on other planets and star systems. And greenhouse gases aren't the only particles causing it. Femke (talk) 17:44, 9 January 2022 (UTC)
- Thanks for the aerosols cite. After that yes I see the first sentence is still not quite right. Before proposing a better one does anyone know what was inaccurate about the original one? As we don't want to reintroduce that inaccuracy. Chidgk1 (talk) 17:58, 9 January 2022 (UTC)
- The earlier sentence said that the GHE was "the warming of the world...". That sentence is wrong. The warming of the world is a result of the GHE, but does not constitute the GHE itself. —RCraig09 (talk) 18:44, 9 January 2022 (UTC)
- Ah I meant what was wrong with the sentence that the academics said was inaccurate which was "The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere."? Chidgk1 (talk) 19:14, 9 January 2022 (UTC)
- @Dave souza: I like your recent improvement to what I wrote in the lede, but since it's fairly specific and detailed, I'm concerned about sourcing. I suggest you provide the source. —RCraig09 (talk) 20:19, 9 January 2022 (UTC)
- Oops, I commented above. It's based on a quick reading of Vaclav Smil (2003), and a look at ref 37 FAQ 1.3 – AR4 WGI Chapter 1: Historical Overview of Climate Change Science attrib. Steve Schneider, but surely a better source can be found? I'm not an expert. . . dave souza, talk 20:31, 9 January 2022 (UTC)
- @Dave souza: I like your recent improvement to what I wrote in the lede, but since it's fairly specific and detailed, I'm concerned about sourcing. I suggest you provide the source. —RCraig09 (talk) 20:19, 9 January 2022 (UTC)
- Ah I meant what was wrong with the sentence that the academics said was inaccurate which was "The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere."? Chidgk1 (talk) 19:14, 9 January 2022 (UTC)
- The earlier sentence said that the GHE was "the warming of the world...". That sentence is wrong. The warming of the world is a result of the GHE, but does not constitute the GHE itself. —RCraig09 (talk) 18:44, 9 January 2022 (UTC)
- Thanks for the aerosols cite. After that yes I see the first sentence is still not quite right. Before proposing a better one does anyone know what was inaccurate about the original one? As we don't want to reintroduce that inaccuracy. Chidgk1 (talk) 17:58, 9 January 2022 (UTC)
By the way the first sentences of Norwegian and Polish featured articles only mention gases - so we may pull ahead of them soon. Chidgk1 (talk) 18:10, 9 January 2022 (UTC)
- we've now got a highly technical sentence. I think it would be good to collect some definitions from high quality sources in a separate section here, and then craft an accurate sentence than 15-yr olds would still understand. I probably don't have time till feb/March.. Femke (talk) 21:11, 9 January 2022 (UTC)
- Ok, a simpler first sentence could be "The greenhouse effect means that a planet's atmosphere lets energy from its sun through to heat the planet's surface, but then hinders heat from the surface from radiating to space so that the surface warms more than it would have done without the atmosphere." Anyway, my aim was a quick fix to get reasonable accuracy, and the rest of the paragraph needs to be simpler when time permits. . . dave souza, talk 22:55, 9 January 2022 (UTC)
It seems you think I made the lede worse - from "inaccurate" to "nonsense" - no; the previous version was accurate. Your version was worse; the current version is still worse than the original. Why are we accepting the assertions of a paper that no-one has read that the original was inaccurate, and why are people that don't really understand it trying to "improve" it? As a Kluw, anything called "climatekid" is not a good source William M. Connolley (talk) 09:45, 10 January 2022 (UTC)
- This version of the original? . . dave souza, talk 11:07, 10 January 2022 (UTC)
- Yes William M. Connolley (talk) 11:16, 10 January 2022 (UTC)
- Thanks! This seems to be the most recent version with that wording. . dave souza, talk 12:16, 10 January 2022 (UTC)
- Yes William M. Connolley (talk) 11:16, 10 January 2022 (UTC)
I tried to mail pdunn2@usc.edu.au
Dear Professor Dunn,
Thank you for your interesting paper on STEM articles on Wikipedia. It has sparked a discussion amongst us Wikipedia editors at https://en.wikipedia.org/wiki/Talk:Greenhouse_effect#Mini-review_of_article_in_paper
Re this particular article on the greenhouse effect could you possibly tell us what was the inaccuracy you found in the first paragraph? We are trying to improve the article - which will hopefully benefit your students in future.
More generally, as we would like to encourage more Wikipedia editing from everyone, would it be possible to make your useful paper freely available? If a wider variety of people edit then that could improve the articles even further for your students.
Finally perhaps you have heard of https://wikiedu.org/ which aims to help you and your students share your knowledge with the world.
Feel free to reply either to this email or directly on the above "talk page".
but the email is rejected
550 SPF Sender Invalid - envelope rejected - https://community.mimecast.com/docs/DOC-1369#550 [9c_i0Ee7NLmWDCgVNCC0fw.au20]
Maybe something wrong with their "Blocked Senders Policy" as I get same problem trying to mail their IT department. Could someone else try please Chidgk1 (talk) 15:44, 10 January 2022 (UTC)
What is inaccurate in the body of the article?
According to the paper above the body of the article is inaccurate, but the paper does not say how. William M. Connolley or anyone - do you know what is inaccurate in the body of the article? As there are 3 featured articles in foreign languages could we replace parts of this article with translations from those? Chidgk1 (talk) 07:39, 9 January 2022 (UTC)
Possibly the inaccuracy is the mention of aerosols - as although it has a global warming potential and causes radiative forcing the black carbon article does not refer to any of its effects as a "greenhouse effect". So maybe aerosols should be removed from this article? Chidgk1 (talk) 13:38, 9 January 2022 (UTC)
- The paper stated that the first paragraph was inaccurate, not other parts. That said, the IPCC AR6 definition says "greenhouse gases, clouds and some aerosols" cause a greenhouse effect. So it's only partially incorrect. Femke (talk) 16:45, 9 January 2022 (UTC)
- Oh yes thanks you are right - it is the procedural explanation and visuals they say are lacking in the article as a whole Chidgk1 (talk) 17:20, 9 January 2022 (UTC)
- The phrase "greenhouse gases, clouds and some aerosols" makes does not acknowledge that clouds are a type of aerosol. I do think there is is value in distinguishing clouds from other aerosols that cause radiative forcing. We should also distinguish between liquid aerosols and solid aerosols (such as black carbon). –Pakbelang (talk) 10:03, 15 January 2022 (UTC)
Initial GHE definition in lede
Sourced definitions:
- "The greenhouse effect is a process that occurs when gases in Earth's atmosphere trap the Sun's heat. This process makes Earth much warmer than it would be without an atmosphere." —From NASA Climate Kids
- "The greenhouse effect is the way in which heat is trapped close to Earth's surface by “greenhouse gases.” These heat-trapping gases can be thought of as a blanket wrapped around Earth, keeping the planet toastier than it would be without them. Greenhouse gases include carbon dioxide, methane, nitrous oxides, and water vapor. (Water vapor, which responds physically or chemically to changes in temperature, is called a "feedback.") Scientists have determined that carbon dioxide's warming effect helps stabilize Earth's atmosphere. Remove carbon dioxide, and the terrestrial greenhouse effect would collapse. Without carbon dioxide, Earth's surface would be some 33°C (59°F) cooler." —From NASA Global Climate Change
- "The Sun powers Earth’s climate, radiating energy at very short wavelengths, predominately in the visible or near-visible (e.g., ultraviolet) part of the spectrum. Roughly one-third of the solar energy that reaches the top of Earth’s atmosphere is reflected directly back to space. The remaining two-thirds is absorbed by the surface and, to a lesser extent, by the atmosphere. To balance the absorbed incoming energy, the Earth must, on average, radiate the same amount of energy back to space. Because the Earth is much colder than the Sun, it radiates at much longer wavelengths, primarily in the infrared part of the spectrum (see Figure 1). Much of this thermal radiation emitted by the land and ocean is absorbed by the atmosphere, including clouds, and reradiated back to Earth. This is called the greenhouse effect." —From AR4 WGI FAQ1.3 (2007)
- "Some atmospheric gases absorb and re-emit infrared energy from the atmosphere down to the Earth’s surface. This process, the greenhouse effect, leads to a mean surface temperature that is 33 °C greater than it would be in its absence. If it were not for the greenhouse gas effect, Earth’s average temperature would be a chilly -18 °C. . . . The Earth has a natural greenhouse effect due to trace amounts of water vapour (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere. These gases let the solar radiation reach the Earth’s surface, but they absorb infrared radiation emitted by the Earth and thereby lead to the heating of the surface of the planet." —From WMO
- "The Sun, which is the Earth's only external form of heat, emits solar radiation mainly in the form of shortwave visible and ultraviolet (UV) energy. As this radiation travels toward the Earth, the atmosphere absorbs about 25% of it, and about 25% is reflected by the clouds back into space. The remaining radiation travels unimpeded to the Earth and warms its surface. The Earth releases back to space the same amount of energy it has absorbed from the Sun. However, the Earth is much cooler than the Sun, so the energy re-emitted from the Earth's surface is much weaker, in the form of invisible longwave infrared (IR) radiation, sometimes called heat radiation. If you stand close to a hot object, but do not touch it, you can feel how the IR radiation heats your skin, although you cannot see the IR rays. . . . Gases that absorb and trap this IR radiation, such as water vapor (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) are known as "greenhouse gases". The atmosphere acts like the glass in a greenhouse, allowing much of the shortwave solar radiation to travel through unimpeded, but trapping a lot of the longwave heat energy trying to escape back to space. This process makes the temperature rise in the atmosphere just as it does in the greenhouse. This is the Earth's natural greenhouse effect and keeps the Earth 33 °C warmer than it would be without an atmosphere, at an average 15 °C (59° F). —From NOAA Global Monitoring Laboratory
- "the greenhouse effect is the natural warming of the earth that results when gases in the atmosphere trap heat from the sun that would otherwise escape into space. . . . Sunlight makes the earth habitable. While 30 percent of the solar energy that reaches our world is reflected back to space, approximately 70 percent passes through the atmosphere to the earth’s surface, where it is absorbed by the land, oceans, and atmosphere, and heats the planet. This heat is then radiated back up in the form of invisible infrared light. While some of this infrared light continues on into space, the vast majority—indeed, some 90 percent—gets absorbed by atmospheric gases, known as greenhouse gases, and redirected back toward the earth, causing further warming." —From Natural Resources Defense Council
- "The infrared radiative effect of all infrared-absorbing constituents in the atmosphere. Greenhouse gases (GHGs), clouds, and some aerosols absorb terrestrial radiation emitted by the Earth's surface and elsewhere in the atmosphere. These substances emit infrared radiation in all directions, but, everything else being equal, 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 GHGs increases the magnitude of this effect; the difference is sometimes called the enhanced greenhouse effect. The change in a GHG concentration because of anthropogenic emissions contributes to an instantaneous radiative forcing. Earth's surface temperature and troposphere warm in response to this forcing, gradually restoring the radiative balance at the top of the atmosphere." —From IPCC Sixth Assessment Report working group 1 glossary (2021)
- The Earth’s climate system is powered by solar radiation (Figure 1.1). Approximately half of the energy from the Sun is supplied in the visible part of the electromagnetic spectrum. As the Earth’s temperature has been relatively constant over many centuries, the incoming solar energy must be nearly in balance with outgoing radiation. Of the incoming solar shortwave radiation (SWR), about half is absorbed by the Earth’s surface. The fraction of SWR reflected back to space by gases and aerosols, clouds and by the Earth’s surface (albedo) is approximately 30%, and about 20% is absorbed in the atmosphere. Based on the temperature of the Earth’s surface the majority of the outgoing energy flux from the Earth is in the infrared part of the spectrum. The longwave radiation (LWR, also referred to as infrared radiation) emitted from the Earth’s surface is largely absorbed by certain atmospheric constituents—water vapour, carbon dioxide (CO2), meth- ane (CH4), nitrous oxide (N2O) and other greenhouse gases (GHGs); see Annex III for Glossary—and clouds, which themselves emit LWR into all directions. The downward directed component of this LWR adds heat to the lower layers of the atmosphere and to the Earth’s surface (greenhouse effect). The dominant energy loss of the infrared radiation from the Earth is from higher layers of the troposphere. The Sun provides its energy to the Earth primarily in the tropics and the subtropics; this energy is then partially redistributed to middle and high latitudes by atmospheric and oceanic transport processes. —From IPCC Fifth Assessment Report working group 1, Chapter 1 p. 126 [glossary looks the same as AR6 above]
- A greenhouse lets in solar energy (mostly in the form of visible light), which keeps it warm ... primarily because its glass windows prevent the wind from carrying away heat. ... The greenhouse effect occurs on our planet because the atmosphere ... contains greenhouse gases [which] are special in that they absorb heat. In doing so, they warm the atmosphere around them. Not all gases are greenhouse gases. In fact, nitrogen and oxygen – the most abundant gases in the atmosphere – aren't greenhouse gases. Fortunately for life on Earth, which depends on some atmospheric warming to exist, other gases are, including water vapor, carbon dioxide, and methane. Without its greenhouse atmosphere, Earth's temperature would plummet to well below freezing. ....
How the Greenhouse Effect Works.
Greenhouse gases allow sunlight to pass through the atmosphere and heat Earth, but they interact with the loss of heat from the land and ocean, redirecting some of the heat back to the surface.
1. Earth absorbs solar energy and heats up
2. Like all warm objects, Earth begins to radiate heat.
Earth radiates heat, which is absorbed by the atmosphere
3. Heat radiating from Earth encounters greenhouse gas molecules in the atmosphere, and is absorbed. The atmosphere warms; as a result, it too radiates heat. Some of this heat is radiated out into space, but the rest is radiated back to Earth's surface. This extra energy warms Earth to higher temperatures. When averaged over several years, the energy radiated into space very nearly balances the solar energy absorbed by Earth. Currently, however, Earth is radiating slightly less heat into space than it is receiving from the Sun, because of the recent addition of greenhouse gases to the atmosphere. Consequently, the planet is warming.
Earth's atmosphere radiates more heat to the atmosphere than it gets from the Sun because of greenhouse gases.
*Mann, Michael E.; Kump, Lee R. (2008). Dire predictions: understanding global warming. DK. pp. 22–23. ISBN 978-0-7566-3995-2. - Visible sunlight penetrates easily through the air and warms the Earth’s surface. When the surface emits invisible infrared heat radiation, this radiation too easily penetrates the main gases of the air. But as Tyndall found, even a trace of CO2 or water vapor, no more than it took to fill a bottle in his laboratory, is almost opaque to heat radiation. Thus a good part of the radiation that rises from the surface is absorbed by these gases in the middle levels of the atmosphere. Its energy transfers into the air itself rather than escaping directly into space. Not only is the air thus warmed, but also some of the energy trapped there is radiated back to the surface, warming it further. Weart: Simple Models of Climate Change
- Beginning with work by Joseph Fourier in the 1820s, scientists had understood that gases in the atmosphere might trap the heat received from the Sun. As Fourier put it, energy in the form of visible light from the Sun easily penetrates the atmosphere to reach the surface and heat it up, but heat cannot so easily escape back into space. For the air absorbs invisible heat rays (“infrared radiation”) rising from the surface. The warmed air radiates some of the energy back down to the surface, helping it stay warm. This was the effect that would later be called, by an inaccurate analogy, the "greenhouse effect."Weart: The Carbon Dioxide Greenhouse Effect
Proposals:
I suggest that editors sign "~~~~" their respective proposals.
- The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.
Radiatively active gases (i.e., greenhouse gases) in a planet's atmosphere radiate energy in all directions. Part of this radiation is directed towards the surface, thus warming it. Similarly, aerosols have radiatively active effects. The intensity of downward radiation – that is, the strength of the greenhouse effect – depends on the amount of greenhouse gases and aerosols that the atmosphere contains. The temperature rises until the intensity of upward radiation from the surface, thus cooling it, balances the downward energy flow.
. . version as of 7 January 2022 - The greenhouse effect is the process in which a planet's atmosphere, when warmed, emits thermal radiation which warms the planet's surface to a temperature above what it would be without this atmosphere. Sunlight passing unhindered through the atmosphere heats the surface, which then emits the energy as thermal radiation. This warms greenhouse gases (and clouds) in the atmosphere, which radiate energy in all directions. Part of this radiation goes down to the surface, warming it. The temperature rises until a higher layer radiates to space as much energy as arrives from the sun, balancing the energy flow.
. . dave souza, talk 16:48, 10 January 2022 (UTC) - In the greenhouse effect, the energy of light from a planet's sun heats its surface, which emits the energy towards space as heat that gets absorbed by air and spreads in all directions, warming the planet's surface to a higher temperature than it would have reached without the air.
Sunlight mostly passes unhindered through Earth's atmosphere and heats the surface. The warmed surface puts out radiant heat absorbed by parts of the atmosphere which warm and radiate heat in all directions, so heat going downwards raises the temperature of the surface. About a third of sunlight gets reflected into space, only 1% of the atmosphere actively absorbs and emits radiant heat, mainly greenhouse gases and clouds. The effect of water vapour varies with temperature, so even a small change in other greenhouse gases causes significant climate change.
. . dave souza, talk 12:04, 11 January 2022 (UTC) tweaked 13:01, 11 January 2022 (UTC), rethought in simple terms 11:23, 15 January 2022 (UTC)) - (Not overly techy, as Femke suggested; and with fewer explanatory tangents) The greenhouse effect is a process that occurs when energy from a planet's sun goes through its atmosphere and warms the planet's surface, but the atmosphere prevents the heat from returning directly to space, resulting in a warmer planet. Light arriving from our Sun passes through Earth's atmosphere and warms its surface. The warmed surface then radiates heat, which is absorbed by greenhouse gases such as carbon dioxide. Without the natural greenhouse effect, Earth's average temperature would be well below freezing. Current human-caused increases in greenhouse gases trap greater amounts of heat, causing the Earth to grow warmer over time.
17:50, 11 Jan, revised 18:04, 13 Jan; 18:07, 15 Jan; 21:20, 26 Jan RCraig09; (edit #4 as requested dave souza, talk 14:26, 28 January 2022 (UTC)); revised 17:44, 28 Jan, 19:53, 29 Jan and —RCraig09 (talk) 19:32, 30 January 2022 (UTC), edits to cover static result pre-industrial, dave souza, talk 06:40, 30 January 2022 (UTC) modified 10:20 - In the greenhouse effect, light from a sun heats a planet's surface, but something in the atmosphere makes it harder for the heat to escape to space, so the planet is warmer than it would have been without this effect. Earth's atmosphere is transparent to sunlight (including visible light and UV light) from the extremely hot Sun. The warmed surface emits radiant heat, nearly all of which is absorbed by Greenhouse gases such as carbon dioxide (CO2), though they are only a tiny proportion of the atmosphere. They heat up, warm the atmosphere, and emit radiant heat in all directions, keeping Earth warmer. Changes to the amount of greenhouse gases can cause climate change, such as global heating from human caused greenhouse gas emissions.
. . . dave souza, talk 18:02, 26 January 2022 (UTC), rethought 14:15, 28 January 2022 (UTC) - ___
- ___
Discussion:
- AR6 definition in body of article and above includes aerosols and clouds. But definition of "radiative effect" on page AVII-48 of AR6 glossary mentions clouds, aerosols and greenhouse effect separately by saying: "Examples include the aerosol-radiation interactions, cloud radiative effect, and greenhouse effect." So are aerosols and clouds in scope of this article or not? Chidgk1 (talk) 19:28, 10 January 2022 (UTC)
- The current version is better, thanks. But heat makes all gas molecules with three or more atoms vibrate and rotate faster is awkward, not very comprehensible, and not quite true - see "details" section. What it wants is something about "radiatively active" gases and a note that most of the atmosphere isn't William M. Connolley (talk) 09:12, 11 January 2022 (UTC)
- Thanks, I've modified it taking these points on board, and put a copy here (#3) which can be compared with #1 the 2021 version, and #2 which modified that. Please edit or suggest improvements.. . dave souza, talk 12:12, 11 January 2022 (UTC)
- I think we must sacrifice exhaustive technical completeness in the initial description for an encyclopedia directed to the general public. Also, as Femke suggested, a 15-year old should be able to understand it readily. My proposal (#4) avoids mention of radiation, thermal radiation, radiative energy, radiatively active effects, lower frequency radiant heat, intensity of upward radiation, downward energy flow, energy flow, ... and elaborations like the effect of aerosols and clouds. Of course I'm open to changes that don't conflict with readability. —RCraig09 (talk) 18:07, 11 January 2022 (UTC)
- Unfortunately "prevents some of the heat reflected from the surface from escaping into space" and "gases heated by the Earth" are wrong: the central point is that heat absorbed in the surface is emitted as IR, not "reflected", and for a balanced energy budget it all has to escape into space: the surface and atmosphere warms until that happens. I've seen "re-radiate" criticised as confusing or misleading.
Can look again at splitting the paragraph into a simplistic first sentence, then the bit after "More specifically" becomes a more technical paragraph suitable for 17 year olds. Please note, the wording "radiant heat" was selected as I think most 15-year olds will have heard of radiant heaters, and can look at one to help to understand it. . . dave souza, talk 18:35, 11 January 2022 (UTC)- Hmmm. I'll ponder, and revise accordingly. I want to avoid a mountain of different proposals. —RCraig09 (talk) 22:02, 11 January 2022 (UTC)
- @Dave souza: I've revised Proposal 4 per your extremely helpful 11 Jan comments. If you have small changes to Proposal 4 that would bring it to your ~full approval, feel free to make them directly to Proposal 4's text (and add your "~~~~" signature to the end). I'm still strongly in favor of a non-techy intro, with minimal explanatory tangents (energy budget, etc.). —RCraig09 (talk) 18:04, 13 January 2022 (UTC)
- @RCraig09:, thanks. I'd already begun a rethink in the simples possible terms, so have now reviewed it and inserted it here in place of #3. See what you think, and make changes where you feel it would be an improvement. In the first paragraph I've used "air" as a non-techy word for atmosphere, change that if you think the latter term works better. I've left out the energy budget as that's currently discussed [badly] in the next paragraph, which is a better place. I've mentioned sunlight reflecting as that's shown prominently in the adjacent picture. . . dave souza, talk 08:18, 15 January 2022 (UTC)
- Thank you again, @Dave souza: I think Proposal 3 is an improvement, and I've adopted some of that content into my twice-revised Proposal 4.
I see the importance of explaining how GHGs radiate in all directions, so I've reluctantly added some length to Proposal 4 for that purpose.I want to avoid comparisons ("than it would have reached without the air") that aren't absolutely necessary. I think that quantifications ("a third", "1%") are distracting to non-technical people, and should go lower in the lede or article body. (I think "atmosphere" is non-techy, though I've substituted "air" when appropriate.) Separately, I'm aware there's some vagueness about the definition of GHG (vs water vapor, vs particulates, etc), but for the first paragraph I'm leaving Proposal 4 to refer to GHGs only. — 18:07, 15 Jan . . Strikeout added —RCraig09 (talk) 23:32, 18 January 2022 (UTC)
- Thank you again, @Dave souza: I think Proposal 3 is an improvement, and I've adopted some of that content into my twice-revised Proposal 4.
- @RCraig09:, thanks. I'd already begun a rethink in the simples possible terms, so have now reviewed it and inserted it here in place of #3. See what you think, and make changes where you feel it would be an improvement. In the first paragraph I've used "air" as a non-techy word for atmosphere, change that if you think the latter term works better. I've left out the energy budget as that's currently discussed [badly] in the next paragraph, which is a better place. I've mentioned sunlight reflecting as that's shown prominently in the adjacent picture. . . dave souza, talk 08:18, 15 January 2022 (UTC)
- Unfortunately "prevents some of the heat reflected from the surface from escaping into space" and "gases heated by the Earth" are wrong: the central point is that heat absorbed in the surface is emitted as IR, not "reflected", and for a balanced energy budget it all has to escape into space: the surface and atmosphere warms until that happens. I've seen "re-radiate" criticised as confusing or misleading.
- Quick comment about suggestion 4: not technically correct. Basically all heat is captured by the air, re-emitted, and captured again and so forth (about 10 times iirc) The fact that the last layer is colder than the surface causes the GHE. Femke (talk) 18:41, 15 January 2022 (UTC)
- I designed my 15 Jan revision to Proposal 4, to avoid the problem you describe.
- I think Proposal 4 communicates best with our predominantly non-techy readers. Feel free to make minor wording changes (e.g., possibly eliminating "more effective") to bring it closer to what consensus desires. (P.S. Where'd everybody go?) —RCraig09 (talk) 23:32, 18 January 2022 (UTC)
- I agree with this, i.e. proposal 4, deleting "more effective". –Pakbelang (talk) 00:31, 20 January 2022 (UTC)
- Having looked at more sources, intend to greatly simplify 3 – some minor word changes could help 4 a bit: "captures some of that energy" implies it doesn't get out and is less simple than "absorbs that energy" – if you're standing in front of a fire, you absorb radiant heat and warm up, which is the main point. "Some of the air's heat-capturing elements" is a vague way of saying "radiates heat, which is absorbed by greenhouse gases and clouds, warming the atmosphere and the surface." No need to name gases in this paragraph. Note that "ground" leaves out sea surface. Omitting "The greenhouse gases radiate heat in all directions, and the heat that is radiated downward warms the Earth's surface" leaves out the central definition of the greenhouse effect from several sources,
but I'm inclined to think that can go in the second paragraphlooking at the sources again, worth trying to rephrase this. The last sentence misses the point that temperatures have been stable, any change in greenhouse gases can cause climate change (whether up or down) but current increases are causing warming. Hope to add sources and edit alternatives next week, am time-limited just now. Noting modifications in 4 is already getting messy . . dave souza, talk 10:31, 20 January 2022 (UTC) strike part, add rethink . 12:00, 20 January 2022 (UTC)- — Sorry, for an intro paragraph for a lay audience, I'm still finding Proposal 3 has too many techy digressions and detailed tangents: ● Quantification (1%, "a third"). ● Unnecessary detailed digressions/tangents (clouds; water vapor especially as relates to changing with temperature). ● Reference to climate change which is the eventual, indirect result of GH Effect (compare to Proposal 4's directly "causing the earth to grow warmer"). Being recited in many references doesn't clear it for inclusion in this opening paragraph for a lay audience.
- — I'm definitely open to wording improvements to Proposal 4 (specific suggested changes are more useful here than critiques). But in all events I think we must keep the intro paragraph simple, simple, simple. That said, I do think mentioning carbon dioxide and methane helps to clarify the mysterious term, "greenhouse gas", for the lay reader. —RCraig09 (talk) 18:12, 23 January 2022 (UTC)
- Simples. Mann and Kump point towards simpler terminology, both they and Henson's The Rough Guide to Climate Change cover the difference to greenhouses before explaining how the GE works, and that's useful for the lay audience these books are aimed at. More detailed topics for the next paragraph include "causing the earth to grow warmer" which is climate change as global warming: the primary point is that the GE stabilises higher temp than no GE. Agree with including CO2 as a common example, methane is more complicated and less significant than water vapour, so intend to cover these further into the lead. . . Work in progress. . . dave souza, talk 18:32, 26 January 2022 (UTC)
- @Dave souza: I'm not sure which terminology your references use that's simpler, but I've simplified Proposal 4 even more. I'm not married to methane but would prefer to keep her in the picture (see diagram at right). Re Proposal 5 (which is diverging discussion rather than converging it): In the opening paragraph I think it's slightly too much detail to explain which direction heat is re-radiated, especially since it's not just the "surface" that's involved in global warming, but the entire lower atmosphere as well. I'm against opening an article with a diversion to a flawed analogy. Is there a minor revision to Proposal 4 that would bring your OK? —RCraig09 (talk) 21:20, 26 January 2022 (UTC)
- @RCraig09:, Weart covers methane: "Tyndall immediately went on to study other gases, finding that carbon dioxide gas (CO2) and water vapor in particular also block heat radiation. Tyndall figured that besides water and CO2, "an almost inappreciable mixture of any of the stronger hydrocarbon vapors" would affect the climate. But there was far more water vapor circulating, and although CO2 was only a few parts in ten thousand in the Earth's atmosphere, that was still much more than other gases. There is so little of Tyndall's "hydrocarbon vapors" in the atmosphere that the most important of them, methane, was not detected there until 1948."
Have rethought Proposal 5 while still covering points in Proposal 4. The flawed analogy is in the title, which is why authors cover that early, but have removed it from the proposal for this opening paragraph.
Have made some minor changes to Proposal 4 as suggested, think the most important is that "trap the heat" means "heat cannot so easily escape back into space". If standing in front of a fire, you'd absorb the heat or soak up the heat, not trap it. (offtopic: tourist asks kilted Scot at breakfast room fireplace "is that your Ayrshire bacon?", he replies "Naw, just warmin' ma haunds".) . . .dave souza, talk 14:48, 28 January 2022 (UTC)- — Sorry, I wasn't asking for an historical explanation of terms; I was actually trying to converge the discussion. Most of your changes to Proposal #4 are OK, though I made some reversions re: ● "nearly all" the heat being absorbed (not true of general definition), ● minor wording change ("Most light..."), ● heat "redirected to warm earth" (unnecessary "extra step", and repetitive of ensuing sentence). Both "captured" or "trapped" are accurate, since that heat doesn't escape to space.
- I'm trying to converge the discussion to a final result. I think Proposal 5, even by itself, isn't converging. Proposal 5 has descriptive issues ("something in the atmosphere", "harder... to escape", "extremely hot" sun, etc) and unnecessary techy diversions ("visible light", "tiny proportion of the atmosphere", "emitting heat in all directions", mentioning ordinary Climate Variability and Change, human GHG emissions, etc) inappropriate for an intro paragraph on GHE for lay readers. I think Proposal 4 is converging and we should finalize it with small refinements. —RCraig09 (talk) 17:44, 28 January 2022 (UTC)
- @RCraig09:, Weart covers methane: "Tyndall immediately went on to study other gases, finding that carbon dioxide gas (CO2) and water vapor in particular also block heat radiation. Tyndall figured that besides water and CO2, "an almost inappreciable mixture of any of the stronger hydrocarbon vapors" would affect the climate. But there was far more water vapor circulating, and although CO2 was only a few parts in ten thousand in the Earth's atmosphere, that was still much more than other gases. There is so little of Tyndall's "hydrocarbon vapors" in the atmosphere that the most important of them, methane, was not detected there until 1948."
- @Dave souza: I'm not sure which terminology your references use that's simpler, but I've simplified Proposal 4 even more. I'm not married to methane but would prefer to keep her in the picture (see diagram at right). Re Proposal 5 (which is diverging discussion rather than converging it): In the opening paragraph I think it's slightly too much detail to explain which direction heat is re-radiated, especially since it's not just the "surface" that's involved in global warming, but the entire lower atmosphere as well. I'm against opening an article with a diversion to a flawed analogy. Is there a minor revision to Proposal 4 that would bring your OK? —RCraig09 (talk) 21:20, 26 January 2022 (UTC)
Thanks for moving a bit forward, however I think Proposal 4 has serious issues and it's at best premature to focus on "converging" and "finalize it with small refinements". Don't mind editing it to explore areas for discussion, but my edits are not endorsement of it as "finalized". What's needed is working towards consensus on the basics to be covered, and finding the best wording to convey these basics to lay readers. On points discussed:
● Weart wasn't for "historical explanation of terms", but for expert views of a physicist and educator, specifically the point that methane is relatively minor overall, regardless of its power per molecule, thanks for leaving that gas out.
● "nearly all" the heat being absorbed "(not true of general definition)" – fair point, but equally your wording as restored "some of the heat" is not general either: isn't "all of the heat" absorbed on Venus?
● "Most light from our Sun passes freely through Earth's atmosphere to warm it" is really "most of the light arriving from the sun", since about half the light reaching Earth is reflected, and some (infrared?) light is absorbed on the way in.
● heat "redirected to warm earth" – for this lay reader, the absorbed heat being emitted in all directions and effectively redirected to warm Earth is essential to understanding.
● "Both "captured" or "trapped" are accurate, since that heat doesn't escape to space" – the energy received from the Sun, transformed into radiant heat, does eventually escape to space, as it did in the stable warmed situation prior to industrial global warming. If the last point can't be conveyed in this opening paragraph, better to leave "Increasing amounts of greenhouse gases ..." etc. to a later paragraph.
Will think about edits. . . dave souza, talk 19:00, 29 January 2022 (UTC)
- @Dave souza: I'm flexible as to exact wording, of course. Observations: ● It's speculative that Venus captures 100.0000% of the heat, so "some of the heat..." is safe wording, ● "most light arriving from the sun..." is OK with me (now changed) ● "redirection...etc" is an "extra step" necessary for deeper understanding but not in the intro paragraph for lay readers ● not "all" heat eventually escapes to space ● conversely, the greenhouse effect on Earth that most incoming readers are seeking, does involve the effect of the "growing warmer over time", and is thus crucial. I think Proposal 4 is both concise and appropriately detailed. 19:53, 29 Jan . . . . Eighty-six of the most beautiful words ever written! —RCraig09 (talk) 19:57, 29 January 2022 (UTC)
- @RCraig09:, in my reading, some of the heat..." implies only a little, so unquantified is safe wording. It strikes me that the defining characteristic of greenhouse gases is that they absorb and emit heat. They don't prevent heat from [eventually] going out, but they do mean it doesn't go freely, and the result is a raised temperature (not rising temperature, which is interim). Have made changes with the aim of allowing a subsequent paragraph to cover the redirecting effect. . . dave souza, talk 07:01, 30 January 2022 (UTC)
- @Dave souza:
I know there may be an ambiguity over the extent of the definition of Greenhouse "effect".19:59, 29 Jan... On second thought, the exact definition of GHE isn't an issue: we're only talking about where to include a particular sentence (about "growing warmer over time"). —RCraig09 (talk) 23:30, 29 January 2022 (UTC)- Thanks, have boldly made 3 edits to cover static result pre-industrial, and greenhouse gases emitting heat, so the paragraph is more universal, subsequent paragraphs to give detail. .. dave souza, talk 07:01, 30 January 2022 (UTC) – after a little copyediting, think this is getting closer. . . dave souza, talk 12:20, 30 January 2022 (UTC)
- I love, love, love the joining of "natural GHE" and "...growing warmer over time"; it's well worth the few extra words required. I think the passages limited to GHE on Earth are ready for publication. However, I think the first sentence—GHE not limited to Earth—can use some fine tuning (e.g., "interacting" seems suboptimal, "resulting in a higher temperature" is vague as to where and I think may be omitted). We'll have to think some more. —RCraig09 (talk) 17:04, 30 January 2022 (UTC)
- @RCraig09: – Thanks! Interacting avoids getting into absorb / emit / redistribute heat cycle, don't have an alternative wording to hand. Have changed "resulting in a higher temperature" to "with the result that the temperature of the planet is increased", we want to be clear that temp doesn't continue to go up without limit. Could be the temp of the planet's surface, assuming it has one. . . dave souza, talk 18:25, 30 January 2022 (UTC)
- @Dave souza: I've just noticed the opening paragraph of the main Climate change article. I can't remember the detailed history, but due to high levels of editor attention it probably has met consensus at some time in the past. The current version recites "Greenhouse gases are transparent to sunlight, allowing it through to heat the Earth's surface. When the Earth emits that heat as infrared radiation the gases absorb it, trapping the heat near the Earth's surface." —RCraig09 (talk) 17:53, 30 January 2022 (UTC)
- Noticed that too, but "the heat" isn't [all] trapped, indeed about as much [heat] energy goes out as comes in from the Sun, and increased heat goes all the way up to "an altitude of roughly 5-6 kilometers [where] the concentration of greenhouse gases in the overlying atmosphere is so small that heat can radiate freely to space."[4] Once we've got this intro together, we can look again at that article. . . dave souza, talk 18:25, 30 January 2022 (UTC)
- Details are in my edit comment, but I've made changes trying to avoid various issues we have perceived. I suggest we continue refining Proposal #4 directly, as I think it's more efficient than longer descriptions here. 19:35, 30 Jan ... The issue maybe needing explanation is that we don't need to include the "extra step" of GHGs radiating heat it just absorbed; that step is implied. —RCraig09 (talk) 19:39, 30 January 2022 (UTC)
- Agree, have made a few minor copyedits, mainly to avoid suggesting light does things "to" warm the earth, it doesn't act purposefully. Leaving the first paragraph alone but using some ideas which came up in these discussions, I've edited the rest of the lead to follow on from the new intro. . . dave souza, talk 15:10, 31 January 2022 (UTC)
- Details are in my edit comment, but I've made changes trying to avoid various issues we have perceived. I suggest we continue refining Proposal #4 directly, as I think it's more efficient than longer descriptions here. 19:35, 30 Jan ... The issue maybe needing explanation is that we don't need to include the "extra step" of GHGs radiating heat it just absorbed; that step is implied. —RCraig09 (talk) 19:39, 30 January 2022 (UTC)
- Noticed that too, but "the heat" isn't [all] trapped, indeed about as much [heat] energy goes out as comes in from the Sun, and increased heat goes all the way up to "an altitude of roughly 5-6 kilometers [where] the concentration of greenhouse gases in the overlying atmosphere is so small that heat can radiate freely to space."[4] Once we've got this intro together, we can look again at that article. . . dave souza, talk 18:25, 30 January 2022 (UTC)
- I love, love, love the joining of "natural GHE" and "...growing warmer over time"; it's well worth the few extra words required. I think the passages limited to GHE on Earth are ready for publication. However, I think the first sentence—GHE not limited to Earth—can use some fine tuning (e.g., "interacting" seems suboptimal, "resulting in a higher temperature" is vague as to where and I think may be omitted). We'll have to think some more. —RCraig09 (talk) 17:04, 30 January 2022 (UTC)
- Thanks, have boldly made 3 edits to cover static result pre-industrial, and greenhouse gases emitting heat, so the paragraph is more universal, subsequent paragraphs to give detail. .. dave souza, talk 07:01, 30 January 2022 (UTC) – after a little copyediting, think this is getting closer. . . dave souza, talk 12:20, 30 January 2022 (UTC)
I think we're ready to WP:BOLDly insert into the article, subject to any other editors' comments or suggestions that come along soon. Our collective goal in the intro paragraph should be to present GHE in layman's terms, while being broad but technically correct. —RCraig09 (talk) 16:56, 31 January 2022 (UTC)
- Boldly implemented. Added cite to the NASA budget source, left Smit in place but think it's too techy. dave souza, talk 07:40, 3 February 2022 (UTC)
Wiki Education assignment: Climate Change Spring 2022
For this course, we student editors mainly focus on greenhouse gases, cloud and aerosol parts ---- now submodules in 'Examples in the atmosphere'. Information on clouds and aerosols are largely enriched. — Preceding unsigned comment added by Yuheng98 (talk • contribs) 19:38, 4 May 2022 (UTC)
A section on Eunice Newton Foote needs to be added to climate change history
From: https://en.wikipedia.org/wiki/Eunice_Newton_Foote Eunice Newton Foote
Newton Foote was a significant force in the scientific community of this period and should be included in a discussion of its history. I'll paste a section from her main article:
Eunice Newton Foote (July 17, 1819 – September 30, 1888) was an American scientist, inventor, and women's rights campaigner. She was the first scientist known to have examined the warming effect of sunlight on different gases and to have suggested that an increase in the proportion of carbon dioxide in the atmosphere would change its temperature and have an effect on climate. Foote was born in Connecticut but raised in New York at the center of social and political movements of her day, such as the abolition of slavery, anti-alcohol activism, and women's rights. She attended the Troy Female Seminary and the Rensselaer School from age seventeen to nineteen, gaining a broad education which included both scientific theory and practice.
Thanks for reading! KingMonkeyNuts (talk) 19:52, 21 July 2022 (UTC)
- Thanks for noticing. I've added some text from climate change. Does the rest of the paragraph make sense now? Femke (talk) 20:02, 21 July 2022 (UTC)
- That looks good! Thanks for adding it. Although there is a bit of a story behind Foote, her work was lost for 100 years or so and recently rediscovered. I think she need more attention for her contribution. Her work predates John Tyndall's work, who was pretty much assumed to be the first word on how CO2 gas absorbs heat.
- This is from her main article: Foote died in 1888 and for almost a hundred years her contributions were lost, before being rediscovered by women academics in the twentieth century. In the twenty-first century, new interest in Foote arose when it was realized that her work predated discoveries made by John Tyndall, who to that point had been recognized by scientists as the first person to discover the greenhouse effect. KingMonkeyNuts (talk) 20:50, 21 July 2022 (UTC)
- The article history of climate change science has more attention for her discovery. I think it would not be WP:PROPORTIONAL to give her history that much more attention than Tyndall in this article. His work was also really important for the history. Femke (talk) 16:39, 22 July 2022 (UTC)
The opening paragraphs are almost complete nonsense, and not just due to grammar
I started to fix it, but the more I went into it, the worse it became. Now I am tempted to just revert it all and let this hot mess just sit there. Fxmastermind (talk) 03:24, 12 September 2022 (UTC)
- You are not wrong! Also, although there is a flaw in the term "Greenhouse effect" it doesn't belong in that paragraph and likely doesn't belong in the lead. The definition section appears clearer to me than the lead, but would still be rather opaque, I think, in getting the concept across to the uninitiated layman.
- The lead should be a summary of the main (and it seems to be attempting to be to some extent). However it is also the first (and often only) part that someone new to the subject will read. How do you describe the Greenhouse effect in 3 paragraphs to someone? Its a bit tricky, but definitely would support attempts to improve this. Sirfurboy🏄 (talk) 07:22, 12 September 2022 (UTC)
- Meh, its not that bad. I've changed it a bit. Just to distract you, Greenhouse gas molecules absorb and emit this infrared, so heat up and emit radiant heat in all directions, warming other greenhouse gas molecules, and pass heat on to the surrounding air is dodgy in that it implies the xfer is radiative, but of course molecular collision is how the non-GHG's heat up; and "surrounding air" is an odd picture William M. Connolley (talk) 08:21, 12 September 2022 (UTC)
- That looks better, thanks. To me it is a lot clearer for not having the aside about the term being wrong sandwiched in the middle of the explanation. Other edits and chops have helped. I am still unsure if the part about a tiny proportion of gases making the atmosphere completely opaque. That still seems to me to be a sentence that is ripe for misunderstanding, but then there is the risk of over-explaining. Not saying I can necessarily do better (or else I would have had a go :) ). Sirfurboy🏄 (talk) 08:40, 12 September 2022 (UTC)
- Meh, its not that bad. I've changed it a bit. Just to distract you, Greenhouse gas molecules absorb and emit this infrared, so heat up and emit radiant heat in all directions, warming other greenhouse gas molecules, and pass heat on to the surrounding air is dodgy in that it implies the xfer is radiative, but of course molecular collision is how the non-GHG's heat up; and "surrounding air" is an odd picture William M. Connolley (talk) 08:21, 12 September 2022 (UTC)