Talk:Global dimming

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Former good articleGlobal dimming was one of the Natural sciences good articles, but it has been removed from the list. There are suggestions below for improving the article to meet the good article criteria. Once these issues have been addressed, the article can be renominated. Editors may also seek a reassessment of the decision if they believe there was a mistake.
Article milestones
DateProcessResult
April 11, 2007Good article nomineeListed
April 14, 2007Peer reviewReviewed
July 30, 2007Featured article candidateNot promoted
April 13, 2008Good article reassessmentKept
November 7, 2020Good article reassessmentDelisted
Current status: Delisted good article

Ohmura article[edit]

I can't find any publication by Ohmura in 1989, but he has four in 1990:

  • Ohmura, A., 1990: Reevaluation and monitoring of the global energy balance. Sanderson, M. (Ed.): UNESCO Source Book in Climatology, 35-42.
  • Chen, J. and Ohmura, A., 1990: On the influence of Alpine glaciers on runoff. Lang, H. and Musy, A. (Eds.): Hydrology in Mountainous Regions I, IAHS Publ., 193, 117-125.
  • Chen, J. and Ohmura, A., 1990: Estimation of Alpine glacier water resources and their change since 1870s. Lang, H. and Musy, A. (Eds): Hydrology in Mountainous Regions I, IAHS Publ., 193, 127-135.
  • Enomoto, J. and Ohmura, A., 1990: The influence of atmospheric half-year cycle on the sea ice extent in the Antarctic. J.Geophys.Res, 95, 9497-9511.

I'd guess that the first one is the most likely to be the relevant paper. -- John Fader 20:09, 15 Jan 2005 (UTC)

(William M. Connolley 21:02, 15 Jan 2005 (UTC)) Thanks. Now all we need is for someone to check the UNESCO book... incidentally, there is something by Ohmura in 1989 (O, Gilgen and Wild, but it looks like a tech rep not in a journal and may well be in German): Ohmura, A., H. Gilgen, and M. Wild (1989), Global Energy Balance Archive GEBA, World Climate Program—Water Project A7, Report 1: Introduction, Zuercher Geografische Schriften Nr. 34, Verlag der Fach-vereine, Zuerich, 62 pp.

Theory behind the program[edit]

(Ferdinand Engelbeen 20:20, 16 Jan 2005 (UTC))

The theory behind the Horizon program, that more sunlight is reflected due to (sulphate) aerosols is at odds with measurements from space.

For the (sub)tropics, in the period 1985-2001 the amount of sunlight reflected by clouds reduced with ~2 W/m2 in the tropics (20N-20S). (see: http://www.atmos.ucla.edu/csrl/publications/pub_exchange/Wielicki_et_al_2002.pdf, confirmed for the 30N-30S (sub)tropics in http://pubs.giss.nasa.gov/docs/2002/2002_ChenCarlsonD.pdf) In the 1985-1994 period, there was a loss of cloud cover, both in the tropics and subtropics (and even up to 60N-60S) of 0.33% and 1.7% respectively.

If there is global dimming at the surface and no more reflection, the only explanation possible is that more sunlight is retained in the atmosphere itself. Which is possible with (dark brown and black) soot particulate. If soot particulate is to blame, then a reduction of it would have a cooling effect, not a warming effect.

Another hint is the amount of reflected sunlight from earth on the moon ("earthshine"), which parallels the "global dimming" trend, while it should have an opposite trend, at: http://www.bbso.njit.edu/science_may28.html (main page at http://www.bbso.njit.edu/ )

Rm cooling effect[edit]

(William M. Connolley 09:23, 27 Apr 2005 (UTC)) Somewhat in a hurry, I removed "This cooling effect may have led scientists to underestimate the effect of greenhouse gases on global warming." from the intro. I'm not really sure it *is* a cooling effect. Certainly a 5% reduction in solar would produce huge cooling, which would be obvious; since that isn't there, the (observed) solar reduction at the sfc is balanced by other effects - the same solar abs at higher levels; or diffuse.

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Article needs updating[edit]

This article appears to have been substantially written and drawing on evidence from 2005 -2007. There is a significant need to review and re-write this article based in more recent evidence eg Daniel Rosenfeld, Yannian Zhu, Minghuai Wang, Youtong Zheng, Tom Goren, Shaocai Yu. Aerosol-driven droplet concentrations dominate coverage and water of oceanic low level clouds. Science, 2019; eaav0566 DOI: 10.1126/science.aav0566 This paper for example suggests that Global dimming is increasing, rather than being replaced with ‘global brightening’ as the Wikipedia GD article suggests. Crit scientist (talk) 10:49, 28 December 2019 (UTC)[reply]

Quantifying the global cooling effect[edit]

The intro says that the effect of global dimming is 0.3-0.7 degrees but it doesn't give a source for the figure. Where is it taken from? --Johannes Rohr (talk) 15:02, 17 January 2020 (UTC)[reply]

GA Review[edit]

This review is transcluded from Talk:Global dimming/GA2. The edit link for this section can be used to add comments to the review.

Reviewer: Clayoquot (talk · contribs) 21:50, 23 November 2023 (UTC)[reply]


Hi InformationToKnowledge. Thanks for nominating this article! I saw on the GAN page that you have been inactive for a few weeks, so I hope all is well with you. I will be reviewing this bit-by-bit. So far I have read the lead and find it nice and clear. I see that there are comments from a previous Good Article Reassessment and will assess whether those issues have been addressed, in addition to the usual checking against GA criteria. Take care, Clayoquot (talk | contribs) 21:50, 23 November 2023 (UTC)[reply]

Just a note that I'm enjoying reviewing this article. Very interesting stuff. Clayoquot (talk | contribs) 05:14, 26 November 2023 (UTC)[reply]

Courtesy notification to GAR reviewers Femke and Chidgk1 that this review is underway. I intend to check whether all of your comments have been addressed and will re-notify you when I've finished checking. Clayoquot (talk | contribs) 20:02, 1 December 2023 (UTC)[reply]

Hi InformationToKnowledge, Do you have any thoughts on my comments so far? Everything has been quiet so I am wondering if this review has been helpful so far. If someone intends to work on this in the near future, I will finish my review and will support you to the best of my ability. If not, just let me know. Clayoquot (talk | contribs) 00:18, 15 December 2023 (UTC)[reply]

Sorry, I actually didn't realize that you left those comments on the 1st in the first place! I received a ping when you had volunteered to do this review, and I assumed that since the article itself and its talk page are on my watchlist, the GA review would show up in my watchlist as well. Turns out it hasn't, and I have been too preoccupied with Greenland ice sheet this month (most likely my next GA nominee) to check on this page.
This review has certainly been helpful, and now that I am aware of these points, I'll try to address them in the very near future! I just have to get a certain page merge (discussed here) out of the way first, if you don't mind. InformationToKnowledge (talk) 17:53, 15 December 2023 (UTC)[reply]
Ha ha, yes it's easy to miss these things! Sure, let's keep going. No rush :) Clayoquot (talk | contribs) 18:08, 15 December 2023 (UTC)[reply]
Just a note that due to real-life busy-ness for the next few weeks I might not progress much. Happy holidays everyone :) Clayoquot (talk | contribs) 03:26, 21 December 2023 (UTC)[reply]
Thank you, and yeah, it seems like we are all slowing down our activity here to celebrate! For now, I acted on one of your suggestions (too much detail regarding cloud interactions) by moving that information to cloud feedback. The rest will have to wait until 2024. InformationToKnowledge (talk) 13:42, 29 December 2023 (UTC)[reply]
Thanks for your recent work on this. I'm back from holidays and should be able to follow up this week. Cheers, Clayoquot (talk | contribs) 06:28, 9 January 2024 (UTC)[reply]
The article is looking much better. Clayoquot (talk | contribs) 00:31, 11 January 2024 (UTC)[reply]

GA review – see WP:WIAGA for criteria

  1. Is it well written?
    A. The prose is clear and concise, and the spelling and grammar are correct:
    Spelling and grammar are fine, with some exceptions that I'll either describe later or fix myself. I have some concerns about jargon and unclear sentences but before I get into the details of those issues it would be best to address the issues around excessive detail described below. Some unclear content should just be removed.
    I have added comments for Criterion 1a in a separate section below.
    B. It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation:
    Unfortunately the lead section is quite far off from the conventions of WP:LEAD. The first sentence should start with "Global dimming is....". There are exceptions to this convention but I think following it here would greatly help the reader.
    The first sentence now starts with "Global dimming is...", which is a major improvement. See Femke's comments below regarding readability and lead length.
    For layout, the "See also" section needs a deep cleanup.
    For words to watch, the weasel words issue raised by Femke seems to have been resolved.
Update: See the section below on Criterion 1b. Clayoquot (talk | contribs) 19:25, 12 January 2024 (UTC)[reply]
  1. There are some instances of MOS:REALTIME to address, e.g. this reversal is only considered "partial" for now.
  2. Is it verifiable with no original research?
    A. It contains a list of all references (sources of information), presented in accordance with the layout style guideline:
    B. Reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose):
    Two of the main issues in the 2020 Good Article Reassessment were outdatedness and uncited text. There has been tremendous improvement in these areas. It's good to see a lot of the article being based on the latest IPCC report.
  1. C. It contains no original research:
    I have added comments for Criterion 2c in a separate section below.
    D. It contains no copyright violations nor plagiarism:
    I ran the article through Earwig's Copyvio detector. It found one pretty clear copyvio sentence, which I removed.
  2. Is it broad in its coverage?
    A. It addresses the main aspects of the topic:
    B. It stays focused on the topic without going into unnecessary detail (see summary style):
  • In the Good Article Reassessment, Femke said, "I don't think the geoengineering section is relevant to this article; I've never seen it in that context." The section has since been improved but I don't think the issue of relevance has been addressed. Solar geongineering is a related topic so it deserves a mention. It's currently positioned as if it's an aspect of the topic of global dimming.
I have found a reliable reference which does use the term in this context. I would rather not make too many other changes to that section as is. InformationToKnowledge (talk) 16:54, 6 January 2024 (UTC)[reply]
The reference you're referring to that relates these concepts is this one, right? I agree the source helps to show the relevance. I'm still concerned about giving wp:undue weight to solar geoengineering - I can get my head around having one paragraph to talk about the relationship between global dimming and solar geoengineering but four paragraphs feels excessive. As Femke raised this issue in the Good Article Review, I'd like to know what she thinks before I sign off on this one.
GA criteria require that Wikipedia:Manual_of_Style/Layout#Section_templates_and_summary_style be followed, which means that if you have a section that summarizes a more detailed article it needs a WP:SUMMARYHATNOTE. I'll add one now. Clayoquot (talk | contribs) 00:43, 11 January 2024 (UTC)[reply]
I think we can find a compromise with the geo-engineering. I believe the last paragraph is a too long for comfortable reading at 170 words (easy-to-read is between 50-100 words, and up to 150 is okay for a majority of readers). That is the paragraph that goes in much too much detail about SRM, way past the "global dimming inspired / gives lessons to" SRM. Can we omit that one, or at least halve it? —Femke 🐦 (talk) 19:54, 11 January 2024 (UTC)[reply]
How about now? InformationToKnowledge (talk) 15:07, 14 January 2024 (UTC)[reply]
  • The section on Aircraft contrails has been greatly improved and made more NPOV. Some of this content would be a good addition to Environmental effects of aviation. However, when reading this section I struggle to relate much of what it's saying to the issue of how much sunlight hits the Earth's surface. I would recommend replacing the entire section with one or a few sentences along the lines of "Aircraft contrails contribute to global dimming but they also trap heat emitted by the Earth. Overall, their warming effect is much greater than their cooling effect."
I have moved a lot of material directly to Contrail and condensed this section substantially, as well as connecting it a bit more to the article's topic. I think it should be enough. InformationToKnowledge (talk) 16:54, 6 January 2024 (UTC)[reply]
Thanks for condensing this. I'm sorry, I'm really struggling to understand this section.
  • What is the significance of diurnal temperature variation? When diurnal temperature variation increases as it did in 2001, what does that tell us?
  • In the sentence However, follow-up studies found that a natural change in cloud cover can more than explain these findings, what findings are explained? Does this sentence mean that all of story from the Sept 11 shutdown is explained by natural causes? If that is the case, why is this story included at all? If it's not the case, what did we learn from the Sept 11 shutdown?
  • What does "no significant response of diurnal surface air temperature range" mean?
  • The last paragraph does not seem to be about aircraft contrails at all. It seems to be a list of points in support of the hypothesis that sulfate air pollution has a cooling effect. I'm not sure if this level of detail is important enough to include. If it must be included, it should go with other pieces of evidence that sulfate air pollution has a cooling effect. It should not go in the section about contrails.
Clayoquot (talk | contribs) 22:37, 11 January 2024 (UTC)[reply]
  • The reader should be able to quickly identify what the main scientific claims are and the level of scientific agreement for each of those claims. Throughout the article, I've been struggling to pick out this information, as it's intermixed with details about individual pieces of evidence. To give one example, in the "Relationship to climate change" section, there is a paragraph that gives the range of estimated temperature decreases caused by aerosol cooling, and says While these values are based on combining model estimates with observational constraints, including those on ocean heat content,[47] the matter is not yet fully settled. The difference between model estimates mainly stems from disagreements over the indirect effects of aerosols on clouds.[71][72] This is great. At that point, the article has described a claim and succinctly explained what kind of controversy there is over the claim. The problem (IMHO) is that instead of stopping at that point, the article gives another 343 words about individual studies that have informed the debate. If this article were anywhere other than Wikipedia there would be nothing objectively wrong with those 343 words, but here I feel they are inappropriate uses of primary sources, are distracting from the main points, and should be removed.
I have now moved those paragraphs to cloud feedback. InformationToKnowledge (talk) 13:42, 29 December 2023 (UTC)[reply]
Super. The issue of key facts being buried amidst experimental methods and data points is a problem in many places in the article. Can you look for and address as many cases as you can find, and let me know when you're done? Clayoquot (talk | contribs) 20:12, 12 January 2024 (UTC)[reply]
  1. Is it neutral?
    It represents viewpoints fairly and without editorial bias, giving due weight to each:
  2. Is it stable?
    It does not change significantly from day to day because of an ongoing edit war or content dispute:
  3. Is it illustrated, if possible, by images?
    A. Images are tagged with their copyright status, and valid non-free use rationales are provided for non-free content:
    File:Xie et al 2022 Asian aerosols.png should be moved to Wikimedia Commons and author information should be stated there as required by the CC-BY license.
    FYI I have nominated File:Bomber stream.jpg for deletion on Commons, but it won't affect this GA review. If it gets deleted there, a bot will remove it from all articles.
    B. Images are relevant to the topic, and have suitable captions:
  4. Overall:
    Pass or Fail:

Criterion 1a: Understandability[edit]

Thanks for putting a definition in the first sentence of the lead. I think I've gotten my head around the topic but it took me a few reads of this article and some of its sources, plus reading some other sources. To meet Criterion #1a (understandable to an appropriately broad audience), here are some ideas for making things easier to understand:

Use terms consistently[edit]

The article seems to use two definitions of "global dimming". In the first definition, global dimming is/was a trend over time. It existed only when each decade was dimmer than the previous, then it ceased to exist in the 1990s. The first definition is used in the lead, "Global dimming was the name given to a decline in the amount of sunlight reaching the Earth's surface, a measure also known as global direct solar irradiance.

In the second definition, global dimming is something that happens whenever there is stuff in the atmosphere that blocks sunlight. Statements such as It is generally believed that the cooling provided by global dimming is similar to the warming derived from atmospheric methane use the second definition.

It is very difficult to make an article understandable when two definitions are in use. What do you think of using the second definition consistently throughout? If I Google "define:global dimming" without quotes most search results seem to use the second definition. The second definition makes much more sense given that stuff continues to be in the atmosphere blocking sunlight.

(More to come) Clayoquot (talk | contribs) 23:27, 22 December 2023 (UTC)[reply]

Here is what the first paragraph of the lead would look like if written to use the second definition consistently:

Global dimming is a decline in the amount of sunlight reaching the Earth's surface, a measure also known as global direct solar irradiance. A dimming trend was observed soon after the first systematic measurements of solar irradiance began in the 1950s, and continued until 1980s, with an observed reduction of 4–5% per decade,[1] even though solar activity did not vary more than the usual at the time.[2][3]
Global dimming is caused by atmospheric particulate matter, predominantly sulfate aerosols. It intensified until around 1990 as a result of rapidly growing air pollution due to post-war industrialization. After 1990, global dimming declined alongside reductions in particulate emissions. This partial reversal of the dimming trend is known as global brightening. Dimming remains more intense than in pre-industrial times.[1] The brightening trend has been globally uneven, as some of the brightening over the developed countries in the 1980s and 1990s had been counteracted by the increased dimming from the industrialization of the developing countries and the expansion of the global shipping industry,[4] although they have also been making rapid progress in cleaning up air pollution in the recent years.[5][6]
Clayoquot (talk | contribs) 19:25, 23 December 2023 (UTC)[reply]
How about the current version? InformationToKnowledge (talk) 16:54, 6 January 2024 (UTC)[reply]
Much better. There are still a few places that suggest global dimming no longer exists, e.g. It was observed soon after the first systematic measurements of solar irradiance began in the 1950s, and continued until 1980s and Global dimming had been widely attributed to... Clayoquot (talk | contribs) 23:10, 11 January 2024 (UTC)[reply]

Minimize switching between facts and myths[edit]

When reading a reference work, the reader wants to be able to quickly find facts. The History and Causes sections contain a mixture of facts and myths, which reflects a chronological writing style. Separate the myths about the causes of dimming (solar variability, natural dust, etc.) into a subsection of the "Causes" section. This could be called something like "Alternative hypotheses". Clayoquot (talk | contribs) 23:28, 23 December 2023 (UTC)[reply]

I think such a subheading might backfire by giving an impression of an ongoing debate where there is none. I have rewritten those sections to a fair extent to help address some of the issues. I suppose that the part describing Asian brown cloud and the Maldives might still be problematic - it was one of the few parts left over from the original article that I didn't really touch. InformationToKnowledge (talk) 16:54, 6 January 2024 (UTC)[reply]
It's going in the right direction. I moved some of the Maldives stuff to the History section. I see your point about an "Alternative hypotheses" section backfiring; maybe a section like this could be called "Discovery" or "Evidence"? In a reference work where we're trying to make science understandable, what is known about a topic often needs to be presented separately from the tortuous path that humanity took to develop that knowledge. A good example of this is the GA Pneumonia, where there is a Causes section with an overview of causes and sub-sections for each type of cause. The Causes section has almost no descriptions of specific studies or pieces of evidence. The story of how we all learned what we know about pneumonia is told in a History section. Clayoquot (talk | contribs) 23:50, 11 January 2024 (UTC)[reply]
Or, instead of having a separate section for Evidence, you could add subsections for individual causes as described below. Then there will be a "Natural emissions" section where you can explain how we know natural emissions are a minor contributor. Clayoquot (talk | contribs) 00:21, 12 January 2024 (UTC)[reply]

Minimize duplication / Keep discussion of each cause together[edit]

The section called "Past and present", under "Relationship to climate change", is largely repetitive with the Hitory and Causes sections. Duplication needs to be eliminated as much as possible. I suggest moving any points that aren't in the History and Causes section to those sections, and deleting the "Past and present" section altogether.

Before merging these sections, I think it would help to split up the "Causes" section into subheadings such as "Sulfate emissions from humans", "Natural emissions", "Black carbon" and "Aircraft contrails". Clayoquot (talk | contribs) 00:21, 12 January 2024 (UTC)[reply]

Criterion 2c No original research[edit]

Here is an example of a statement that seems to be original research: Starting from 2005, scientific papers began to report that after 1990, the global dimming trend had clearly switched to global brightening.[28][39][40][41][42]. If you want to include this kind of statement, you need a secondary or tertiary source that states this directly, i.e. a source that has surveyed the literature from that time period. Quite a few statements in the article are about the history of science around global dimming, rather than being about the science itself. The history of science in this topic area is interesting, but it needs to be written by non-Wikipedians and then summarized by Wikipedians. And there should probably be a lot less of it - in a reference work the reader wants the conclusions of the scientific journey, they don't want the journey. Clayoquot (talk | contribs) 23:42, 23 December 2023 (UTC)[reply]

By now, I have both added a couple of references that talk about the historical context and rewrote some statements like this. InformationToKnowledge (talk) 16:54, 6 January 2024 (UTC)[reply]

Criterion 2b Staying focused on the topic[edit]

I don't see how to following passage is relevant: In the late 1960s, Mikhail Ivanovich Budyko worked with simple two-dimensional energy-balance climate models to investigate the reflectivity of ice.[25] He found that the ice–albedo feedback created a positive feedback loop in the Earth's climate system. The more snow and ice, the more solar radiation is reflected back into space and hence the colder Earth grows and the more it snows. Clayoquot (talk | contribs) 04:49, 23 December 2023 (UTC)[reply]

That was left behind from the older version of this article. I didn't check it thoroughly then, but you are right, it doesn't belong here, and I moved it to ice-albedo feedback. InformationToKnowledge (talk) 16:54, 6 January 2024 (UTC)[reply]
Great, thanks. Clayoquot (talk | contribs) 23:51, 11 January 2024 (UTC)[reply]

Readability and understandability[edit]

Thanks for the ping Clayoquot. I think the key improvement still needed is around readability, related to 1a (WP:make technical articles understandable) and 1b (WP:LEADLENGTH). Hemingway says the lead is now written for a post-graduate audience, and I agree. Even though I've studied this as part of my PhD, I struggle with the text (with minor long covid brain fog tbf). Can we reduce the lead length by 1/3 or at a minimun 1/4? Then we'd be on the upper end of a typical lead. And reduce length mostly by reducing sentence length? A few examples of copy-editing for comprehension. ItK, I can strongly recommend the use of large language models in improving readability. The prompt that often works for me is "Can you say X more concisely and simple". :

  • Instead, global dimming had been attributed to an increase in atmospheric particulate matter, predominantly sulfate aerosols, as the result of rapidly growing air pollution due to post-war industrialization --> Instead, global dimming was due to
  • After 1980s, reductions in particulate emissions have also caused a "partial" reversal of the dimming trend, which has sometimes been described as a global brightening --> Since the 1980s, a decrease in air pollution has led to a partial reversal of the dimming trend, sometimes referred to as global brightening.
  • The last superlong sentence of the lead --> The dimming reversal is not complete and varies worldwide. Brightening in developed countries during the 1980s and 1990s was offset by increased dimming in developing countries and by the expansion of the global shipping industry. In recent years, air pollution in developing countries has improved rapidly. (The "they" feels a bit odd here, as if we're assuming the reader is from the global north..)

—Femke 🐦 (talk) 19:54, 11 January 2024 (UTC)[reply]

Thank you for this detailed input and for the link to the Hemingway app. I agree understandability is a problem and these suggestions would help. Clayoquot (talk | contribs) 21:44, 11 January 2024 (UTC)[reply]

Criterion 1b: Words to watch[edit]

See MOS:WEASEL regarding phrases such as Global dimming has primarily been attributed to.... I don't see a reason not to say "Global dimming is primarily caused by...". State facts as if they are facts. Clayoquot (talk | contribs) 19:18, 12 January 2024 (UTC)[reply]

Criterion 3: Media and captions[edit]

In the first image of the "Causes" section, does As it moves through the atmosphere with prevailing winds, weather patterns and seasonality alter these distributions from day-to-day. need to be in the caption? Clayoquot (talk | contribs) 19:38, 12 January 2024 (UTC)[reply]

I am confused by the caption Big Brown Cloud Storm over Asia.. Why the capital letters? Does this image show the Asian brown cloud or is a "brown cloud storm" a different thing? Clayoquot (talk | contribs) 19:41, 12 January 2024 (UTC)[reply]

For the first image in the "Relationship to climate change" section, the image says "sulphur dioxide" but the caption says "sulfate aerosols". The caption needs to explain what the relationship is between them. Also "including the cooling provided by sulfate aerosols and the dimming they cause" suggests (erroneously?) that sulfate aerosols provide cooling by another mechanism in addition to dimming. Clayoquot (talk | contribs) 19:44, 12 January 2024 (UTC)[reply]

For File:Glantz 2022 Europe aerosols.jpg, after reading the caption several times and looking at the full-size image file, I still cannot figure out what this image is saying. Can you explain in other words 1) what data the image shows, and 2) what the image tells us about global dimming? Clayoquot (talk | contribs) 19:54, 12 January 2024 (UTC)[reply]

For File:Smith 2020 SAI RCP scenarios.jpg, I cannot understand this at all. It might help to split the caption into smaller sentences, but it's probably best to formulate a one-paragraph plain-language takeaway and include that instead of the image. If you use the term "Representative Concentration Pathway" you will need to explain what that means. Also spell out SAI. Clayoquot (talk | contribs) 20:00, 12 January 2024 (UTC)[reply]

Review summary[edit]

Hi InformationtoKnowledge. I've finally finished a first pass of my review. I will never use GA review templates again - what a pain. To summarize where we are:

  • The article is scientifically very strong. We are lucky to have someone as knowledgeable as you in our community.
  • Regarding the GAR, I believe the issues raised there have been either addressed, or were partly addressed and have come up again in this review. Regarding @Chidgk1:'s point that "variation in the radiation emitted by the sun needs to be clearly distinguished from variations in how much is absorbed by the atmosphere", I think the article now does this well.
  • The main issue is understandability for non-experts. Problems with understandability arise from issues at several levels: Curation (choosing what to leave out), using summary statements, article structure, use of plain language versus jargon, word length, and sentence/length and structure. It is generally easiest to start by removing and summarizing excessive detail, and then moving towards refining the sentences. Let me know how I can help.

Cheers, Clayoquot (talk | contribs) 20:31, 12 January 2024 (UTC)[reply]

Thank you! Just letting you know that I'll be gradually responding to this over the next few days. InformationToKnowledge (talk) 15:09, 14 January 2024 (UTC)[reply]
Fantastic. When you've addressed as many issues as you can, let me know and I'll give the article a top-to-bottom re-read. I'm aiming to not to re-read individual changes or sections until then, both to save myself time and to avoid becoming too familiar with the content. Cheers, Clayoquot (talk | contribs) 21:45, 15 January 2024 (UTC)[reply]
Hi @Clayoquot and @InformationToKnowledge, courtesy reminder ping that this is still outstanding. -- asilvering (talk) 02:08, 4 March 2024 (UTC)[reply]
Thanks for the reminder. InformationToKnowledge, do you want to continue with this review? If not, I'll mark it as failed for now but you can re-nominate it at any time if you choose. Clayoquot (talk | contribs) 04:34, 4 March 2024 (UTC)[reply]
Yes, for sure! We seem to be really close now: it's just that splitting and reorganizing much of the current article layout into subsections, as you suggested, is a bit of a chore, and a range of higher-view and/or far more problematic articles have blotted out my radar over the past month and a half. (i.e. see the work on Climate change itself, or on Southern Ocean overturning circulation and the other Antarctica-related articles.) I am certainly not abandoning this GA outright, though, and I should be able to set aside enough time for it very soon. InformationToKnowledge (talk) 14:09, 4 March 2024 (UTC)[reply]
Excellent! Clayoquot (talk | contribs) 15:18, 4 March 2024 (UTC)[reply]
So, I started to implement some of your suggestions in regards to reorganizing the article (i.e. splitting up the section on causes and moving contrails.) It is still not close to done (i.e. the section on black carbon clearly needs expansion, and I have not yet settled on the best way to address your questions about certain graphics), but it's been an important step forward. InformationToKnowledge (talk) 14:15, 10 March 2024 (UTC)[reply]

Use “sunlight” instead of “irradiance” in first 2 sentences?[edit]

I wonder if that might be better as more readable? Chidgk1 (talk) 07:39, 17 December 2023 (UTC)[reply]

How about now? InformationToKnowledge (talk) 11:40, 17 December 2023 (UTC)[reply]

I see this article is currently undergoing a GA review. That's great. I came to this article as I am currently looking at improving radiative forcing. I wonder if the term "global dimming" is just an "easier to understand term" for something that is already covered in some other articles as well. Namely in the article on particulates. From the main climate change article I get sent to Particulates#Climate effects and now I am wondering if that section doesn't already cover the same content as what is at global dimming? If not then how do the two articles interact, is one the parent article of the other? Might be worth looking at so ensure we don't repeat the same content in two places or at least to ensure that the two articles interlink well.

My suggestion would be to include in the global dimming article a bit more on the political/historical aspects, i.e. how the global dimming phenomenon was used by climate change deniers/skeptics for a long time (although I now see that the climate change denial article doesn't even mention global dimming once). But see e.g. History of climate change science#Discredited theories and reconciled apparent discrepancies. The article Scientific consensus on climate change mentions "global dimming" just once in the section about the 1970s. So I guess this is about interlinking this article with the other ones. EMsmile (talk) 12:30, 16 January 2024 (UTC)[reply]

Yes, there have been issues with article overlap regarding this general subject for a very long time. I noted exactly that on the WikiProject talk page (now archived) when I started work on this set of articles from about March to May last year. One reason why there is overlap in the Particulates article is because pulled much of the salvageable content from very low-quality Stratospheric sulfur aerosols there (in addition to this article and solar geoengineering) before merging that into stratospheric aerosol injection. SAI now has the most daily pageviews of the three, which is a little unfortunate, since it was the one I worked on the least - in part because it used to be well behind this article and SG back then.
Anyway, Particulates was never meant to be a long-term destination for that information. Back then, it was an overlong article that struggled with proportionality in section size, layout, etc. and had an lots of overlap with air pollution (which itself suffers from many of the same issues) - and it is basically the same now, still. I believe you suggested making that article about all forms of particulate matter, including in water, and that might work if the article is covering types of particulate matter and the details about health effects, etc. are moved to Air pollution - but that would be a really complex merge, painful cuts may need to be made to combine two already large articles, and the merge discussion there might make the climate apocalypse one (recently closed with no consensus) look easy by comparison.
I think you had also suggested sometime last year that the climate-related material in Particulates should really be in Aerosol, and strictly speaking, that would be absolutely right, as the IPCC and effectively all the research papers use the term aerosol in the climate context, while particulate is generally limited to health context. The issue is that the Aerosol article is itself an unholy mess, with relatively few paragraphs and only a couple dozen unique references (some of which are cited 10-20 times as separate references - usually the ones that are from 1990s and 1980s), but with lots of protracted equations. (Somehow, it still consistently gets >500 daily views month after month, suggesting readers don't mind?) It also has relatively little detail on climate but some paragraphs that go into health effects - these should probably be exchanged with particulates' climate effects paragraphs before anything else is done.
From the main climate change article I get sent to Particulates#Climate effects and now I am wondering if that section doesn't already cover the same content as what is at global dimming?
Firstly, I would say that while Particulates#Climate effects is not as bad as Aerosol is right now, everything it says before the "Sulfate" heading is also not great, with too many over-long sentences and citations from 2000s like AR4. Hopefully, we can be fixed after we move it to aerosols, but it might take some time. For now, I have just removed your "See also" link heading there for that reason. That and because the Aerosols section in Climate change (your other "See also" link) is effectively just a very short summary of that exact section, so linking it is completely counterproductive. You have done the same thing earlier on Greenland ice sheet - linking to the section in sea level rise which only provides a brief overview of that exact article. Please try to be more careful with that next time!
Secondly, that section is only about the impact on temperatures, and does not really say anything about either, well, the visual dimming itself, or, more importantly, the hydrological impact - which had been credibly linked to an major famine, as this article now describes. In theory, a revised version of Aerosol might be able to fit all that information, but I suspect it would look very awkward and bloated and worse than what we have now.
i.e. how the global dimming phenomenon was used by climate change deniers/skeptics for a long time
The thing is, I am not sure it was really used in that way in any meaningful sense. One of the references that's been here for a very long time is a 2003 article from The Guardian, which claims that it was largely obscure as recently as 20 years ago. (Though, since even the 1990 IPCC report talked about it at length, I suspect a lot of that is The Guardian's typical exaggeration - that article did not age well at all in many respects.) As stated in scientific consensus on climate change, the scientists who disagreed with the consensus also seemed to incorrectly attribute the cooling from dimming to volcanoes - at least in that one survey I found.
If there is one article where there really is an overlap in that regard, it's global cooling - but that article also looks like it could benefit from substantial clean-up, with a lot of poorly structured direct quotes and other issues like that. Still, two or three references look usable, so I'll have to think about it. InformationToKnowledge (talk) 14:17, 16 January 2024 (UTC)[reply]

Question about image and its caption[edit]

The extent to which physical factors in the atmosphere or on land affect climate change, including the cooling provided by sulfate aerosols and the dimming they cause. The large error bar shows that there are still substantial unresolved uncertainties.

Hi InformationToKnowledge: you put this graph back in which I have just removed (see on the right): The reason why I had removed it was because I don't think it was specific enough for this article. Also the caption looked out of date for me and without a reference? On the article radiative forcing I have given it a different caption and the exact source, see on the right the second graph.

Warming contributions of various GHGs, agents, factors [name the year that the contributions pertain to] [*correct reference given under the 'Talk' tab*]. Plus, the figure is inaccurate; at least wrt. to methane.
Contributions to warming: The graph shows "temperature changes from individual components of human influence".[7]: 7 

Could we at least agree to improve the caption with a source here as well? Making it clear and understandable to lay persons?

The same graph appears in quite a few articles by the way, and I think in each case the caption should be looked at (and adapted if necessary) and the source given, with page number:

  • Attribution of recent climate change
  • Cloud feedback
  • Sulfur dioxide
  • Global dimming
  • Radiative forcing
  • Climate change
  • Carbon dioxide in Earth's atmosphere
  • Greenhouse gas
  • Atmospheric methane
  • Gas venting

P.S. I know that the source can be found by readers when they click on the image but I think it's good practice to add the source also to the caption itself, just to be sure.

References

  1. ^ a b Cite error: The named reference IPCC_WGI_Ch11 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Eddy et al. 1982 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference AGU2021 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Wild2009 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference XuRamanathanVictor2018 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Quaas2022 was invoked but never defined (see the help page).
  7. ^ IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 3−32, doi:10.1017/9781009157896.001.

EMsmile (talk) 13:45, 16 January 2024 (UTC)[reply]

I mean, that graph is used on a lot of articles because it really is very useful. It might need to be removed from some of those, but certainly not this one. As for the source, yes, the first sentence should be sourced to SPM, while references 76-78 in the article all make the case that there is unfortunately still a lot of uncertainty about the exact amount of cooling, which is why that large error bar is needed (It is not "outdated" at all!) I simply overlooked adding one or all of them to the caption that time. InformationToKnowledge (talk) 14:26, 16 January 2024 (UTC)[reply]
OK, but this wording in the caption is unclear to me: "including the cooling provided by sulfate aerosols and the dimming they cause". Is cooling and dimming now two different things here? Also this sentence could be made clearer by adding the words in bold: "The large error bar for the contribution of sulphur dioxide in particular shows that there are still substantial unresolved uncertainties." And what are "substantial unresolved uncertainties", surely there could be simpler wording for that? Is that source on page 7 saying it in those exact words? Does that uncertainty get explained in the main text? I only see it mentioned twice in the Wikipedia article text. Perhaps it deserves a separate sub-heading? EMsmile (talk) 15:34, 16 January 2024 (UTC)[reply]

Better section heading for the solar geoengineering section?[edit]

Could we come up with a better section heading for the section that is currently titled "solar geoengineering"? All the other section headings are clear and generic, except for this one. Here is the table of content's structure to date:

History
Causes
Relationship to climate change
Past and present
Future
Relationship to hydrological cycle
Solar geoengineering

Maybe change it to: "Relationship with xxx" or "Applications" or "Interactions with xx"? EMsmile (talk) 13:49, 16 January 2024 (UTC)[reply]