Talk:Carbon dioxide/Archive 4

Ratio of densities
I am making reference to the very first sentence in the article, which says that “Carbon dioxide is a colorless gas with a density about 60% higher than that of air (1.225 g/L)”. In my opinion, carbon dioxide has a density about 50% (not 60% !) higher than that of air. Even by taking into account the presence of water vapor in air, and treating both CO2 and air as real gases by means of van der Waals’ equation, the ratio of the two densities turns out to be much closer to 1.5 than 1.6. Therefore, I suggest to replace 60% with 50%.Ekisbares (talk) 14:00, 20 July 2017 (UTC)

After waiting about two months for comments, I decided to make the above suggested replacement. Actually, as regards the sentence in the previous version, stating that carbon dioxide has “a density about 60% higher than that of air (1.225 g/L)”, it is likely that the figure of about 60% has been obtained by dividing the density of CO2 as reported in the side-box of Properties of that substance (“1.977 kg/m3 (gas at 1 atm and 0 °C)”) by that of air as reported at the beginning of the article (1.225 g/L). But the latter figure, which was probably taken from Wikipedia article about the Density of Air, is the density of (dry) air at 1 atm and 15 °C, and obviously that ratio produces a meaningless result. If both gases are compared at 1 atm and 15 °C (this temperature being more representative of the average terrestrial conditions), the ratio is about 1.53. For a more realistic comparison, we have to consider that air always contains a variable amount of water vapor, a fact that decreases its density. But even if we allow for the presence of a 100% of humidity in air at 15 °C, the ratio rises only to 1.54. Ekisbares (talk) 14:33, 17 September 2017 (UTC)


 * By the ideal gas law the ratio of densities works out to the ratio of molecular weights, or roughly 44.0/29.0 = 1.52. Pressure and temperature are irrelevant. So you're correct that it's closer to 50% than 60%, even though you arrived at the answer in a way that doesn't take into account the fundamental reason. Shock Brigade Harvester Boris (talk) 14:44, 17 September 2017 (UTC)

Together with any elementary-level student of chemistry, I am well aware of the fundamental fact, coming out of Avogadro law, that the ratio of densities of gases is equal to the ratio of their molecular weights (average molecular weight for air), provided the gases are considered as ideal, and the comparison is made at the same temperature and pressure. But in order to provide more realistic data to the average users of Wikipedia, which are supposed not to be specialists in chemistry, I directly took the ratio of the real gases, at a temperature and pressure that might be representative of the average terrestrial conditions (in comparing the densities of real gases, temperature and pressure are not irrelevant); I also took into consideration the presence of water vapour. With respect to considering both gases as ideal, the differences turned out to be minimal. Ekisbares (talk) 16:24, 17 September 2017 (UTC)

Rising CO2 toxic?
, the other day you reverted an edit I made. I had added a qualifier to a sentence claiming that rising CO2 levels may soon constitute a danger to human health. My qualifier pointed out that human breath contains more than 100 times as much CO2 as the atmosphere. Your comment was, "WP:SYNTH for relevance. The atmosphere is not monolithic, else ground-level ozone would be a good thing".

Please explain. Do you really think CO2 will be dangerous for human health, at a level of, say, 500 ppm, when our breath contains about 5% (50,000 ppm)? What does this have to do with whether the atmosphere is monolithic?

Eric Kvaalen (talk) 07:51, 18 September 2017 (UTC)


 * The bit about breath sounds like SYN to me, too. OTOH the first ref looks to be self-pub with no particular status (add it back if you think otherwise, or there's some reason why it is a good ref) and the language looked stronger than demanded, so I weakened it William M. Connolley (talk) 13:01, 18 September 2017 (UTC)


 * I know that some people interpret the policy on "synthesis" as though it means we cannot put anything into an article if it involves using our head a little bit! But I don't think that's how that policy should be interpreted. If a sentence seems stupid, there's nothing wrong with putting in a caveat so that people will see that it's stupid. Frankly I would prefer that the article didn't say anything on the subject of a potential future health risk unless it is that there is none (for the very reason that I have pointed out -- the concentration is much too small). In fact, now that you have taken out the reference, the statement is unsupported, so we may as well remove it completely. Eric Kvaalen (talk) 13:32, 18 September 2017 (UTC)


 * It may partially depend on your definition of a "health" impact. Studies   have pointed to measurable, but mild, declines in cognitive performance when exposed to 1000 ppm.  Dragons flight (talk) 14:12, 18 September 2017 (UTC)


 * Um. To take the first of those links, that's somewhat problematic, because as it says These impacts have been observed at CO2 levels that most Americans — and their children — are routinely exposed to today inside classrooms, offices, homes, planes, and cars. So, meh, if you accept that then the climate change connection disappears: the problems are mostly due to air rebreathing. So I'm not sure what we'd do about that (I mean, in this article) William M. Connolley (talk) 16:06, 18 September 2017 (UTC)


 * For example, puffs of higher concentration exhaled are not the same as long-term exposure via inhalation. WP:SYN is exactly a problem when you draw your own conclusions, especially with regards to effects of raw biochemical data. DMacks (talk) 14:38, 18 September 2017 (UTC)


 * But we're not talking about puffs of exhaled air. The air in our lungs is always around 5% (unless you hyperventilate). Again, I think we should just get rid of the sentence. It now has no reference! Eric Kvaalen (talk) 14:47, 18 September 2017 (UTC)

"It occurs naturally at a concentration of 400ppm"
Shouldn't this be a little controversial? Arguably, it occurs naturally [at least, in this geological era] at concentrations of 280ish ppm and we've boosted it to 400+ppm since then...
 * Yes, I think it is worded in a way that is potentially misleading. The first part of the phrase, "It occurs naturally in Earth's atmosphere as a trace gas", is of course correct, but the rest of the phrase, "at a concentration of about 0.04 percent (400 ppm) by volume" implies that the current concentration is natural.  It is not until 4 paragraphs later that the fact of increasing CO2 concentrations in the industrial era is introduced.  I think separating the two parts of the sentence could avoid giving the misleading impression.  Perhaps, "It occurs naturally in Earth's atmosphere as a trace gas.  The current concentration is about 0.04 percent (400 ppm) by volume, having risen from pre-industrial levels of 280 ppm." — Preceding unsigned comment added by Edgar181 (talk • contribs) 15:46, 23 January 2018 (UTC)
 * Was going to say pretty much the same thing about splitting the two ideas, and Edgar's wording is at least as good as what I was going to write. DMacks (talk) 16:03, 23 January 2018 (UTC)


 * this statement is really stupid because it naturally occurs all the way up to 7000ppm, depending on how far back in time you go. It should specify that it occurs at 280 or 400ppm at this point in time, but has been known to fluctuate drastically over millions of years — Preceding unsigned comment added by 24.194.170.120 (talk) 09:27, 20 March 2018 (UTC)
 * Carbon dioxide in Earth's atmosphere seems to cover the historical perspective well. Here, we are mostly talking about now. DMacks (talk) 15:01, 20 March 2018 (UTC)
 * Also this article has a section In Earth's atmosphere, which includes the sentence Five hundred million years ago the carbon dioxide concentration was 20 times greater than today, decreasing to 4–5 times during the Jurassic period and then slowly declining with a particularly swift reduction occurring 49 million years ago. So the information is there. Dirac66 (talk) 18:55, 20 March 2018 (UTC)

Incorrect info

 * . It is an unwanted byproduct in many large scale oxidation processes, for example, in the production of acrylic acid (over 5 million tons/year).[6][7][8][9]

The sources do not verify the claim at all, neither does Acrylic acid. Please remove or correct.5.198.10.236 (talk) 07:48, 1 July 2018 (UTC)

Industrial CO2 production
There seems to be a scarcity regarding how it works (there are some mention on how it does not) and no statistics in production and utilization and percentage of contribution to annual atmospherics increase/decrease or why on how it can't be turned into a cycle linked to sequestration. --109.49.141.100 (talk) 20:47, 21 June 2018 (UTC)
 * That's a lot of topics, and some of them may be too specific for this article. I think some of what you want is in other articles already, such as Carbon dioxide in Earth's atmosphere. --OuroborosCobra (talk) 18:44, 26 June 2018 (UTC)
 * That was my point there is lot of information missing (even a link to another article that covers it would work)...
 * No information on industrial CO2 production besides some mentions, no numbers on what is produced what is used by industry and again what impact it has on atmospheric levels and how or why not it isn't done in conjunction with sequestration efforts (in place of producing it from stable repositories of CO2).
 * Will check the link you prodded but I don't think that it will cover this subjects (the article topic is more restricted there) (It doesn't, as expected) --109.49.141.100 (talk) 03:50, 8 July 2018 (UTC)
 * There isn't all that much besides burning fuel and producing cement which is mentioned in the article. After that you're into things like extracting it from natural gas and or using it in dry ice but that doesn't contribute anything very relevant to climate change. Dmcq (talk) 09:41, 8 July 2018 (UTC)
 * I was not referring to CO2 as an industrial by-product but on intentional creation for industrial processes, like beverage gasification and other uses. How much is produced and the reasons why it can't be re-purposed from those sources you mentioned or even re-captured from the atmosphere (in place of other more stable repositories). That was what I was after, and percentages comparison about human sources that included intentional production of CO2. --109.49.141.100 (talk) 18:07, 22 July 2018 (UTC)

Reference link moved – appropriate solution?
Reference 117 (entitled “Carbon Dioxide as a Fire Suppressant: Examining the Risks”) currently points to the link: http://www.epa.gov/ozone/snap/fire/co2/co2report.html. This link is dead, redirecting to http://www.epa.gov/ozone/snap.

I have found an archived version of the page on the internet archive, but I have also found where the original page was moved to on the EPA site.

Should I include both URLs (the archive and the new link) in the citation, or just one or the other? If both, how do I do that?

(For the moment, I will update the link to point to the archived version.)

PriapicPrimate (talk) 00:07, 27 December 2018 (UTC)


 * I think the way you have done it is good. The link to the working copy is provided first so most readers can just follow that link, but the link to the original EPA site is at the end for anyone who wants to see what that link now looks like. Dirac66 (talk) 15:57, 31 December 2018 (UTC)

LIE
"Human activities have caused CO2 to increase above levels not seen in hundreds of thousands of years. "

We know the increase but we have no definitive knowledge about the causes. During the Cambrian period the earth faced a CO2 level 0f 4000 ppm without any human walking on this planet. Maybe the increase is totally natural.

62.226.80.199 (talk) 21:56, 19 July 2019 (UTC)
 * "We have no definitive knowledge" - With "we", you mean yourself and who else? Definitely not the climatological community. --Hob Gadling (talk) 04:13, 21 July 2019 (UTC)

Density of carbon dioxide vs. air
The entry says: ‘Carbon dioxide (chemical formula CO2) is a colorless gas with a density about 60% higher than that of dry air.' and ‘At standard temperature and pressure, the density of carbon dioxide is around 1.98 kg/m3, about 1.67 times that of air.’ In the table, it gives the density of carbon dioxide as 1.977 kg/m3 (gas at 1 atm and 0˚C). If we look up the density of air at 0˚C, it is 1.2922. Comparing these two figure, we would conclude that the density of carbon dioxide is 1.53 times that of air, a figure that is often found elsewhere.

The figures ('60% higher'; '1.67 times') stated in this entry most likely were derived using the air density at 15˚C (1.2250) for comparison. Shouldn't we compare the density of two airs at the same temperature?

Cartonchen (talk) 01:07, 23 October 2019 (UTC)

— Preceding unsigned comment added by Cartonchen (talk • contribs) 01:00, 23 October 2019 (UTC)

Mature forests
It is claimed that "Contrary to the long-standing view that they are carbon neutral, mature forests can continue to accumulate carbon[124] and remain valuable carbon sinks, helping to maintain the carbon balance of Earth's atmosphere. " There is no explanation that since mature forests are in the net not growing, then where and in what form and to what degree does this claimed carbon absorption from the atmosphere get sequestered? This appears to be an ideological statement. — Preceding unsigned comment added by Forkhume (talk • contribs) 10:11, 31 March 2020 (UTC)
 * It's cited so you can look up ref #124 and see the underlying basis that strongly and directly supports this wording. DMacks (talk) 10:21, 31 March 2020 (UTC)

Never linear - refers to all linear triatomics
The recently added point at the end of the Structure and bonding section points out that "In a gas phase sample of carbon dioxide, none of the molecules are [instantaneously] linear as a result of the vibrational motions. This is shown both by theory and by Coulomb explosion imaging experiments." I have looked at the referenced paper by Jensen, Spanner and Bunker, and I note that this is really a property of all linear triatomic molecules ABC. The only thing which specifically refers to CO2 is that experiments have been done to confirm the distribution of instantaneous angles due to the molecular bending vibration.

I would suggest therefore that this point should be moved from the CO2 article to the article on Linear molecular geometry, as a general property of linear molecules or at least of linear triatomic molecules. Dirac66 (talk) 01:01, 7 July 2020 (UTC)
 * I agree that there is more to this than just a single primary-source journal ref, certainly enough to mention in the general molecular-geometry article. I don't see this as a notable aspect of CO2. It's true that CO2 is a prototypical molecule of this class and a specific one probed, but it appears it's not the only one to have experimental support for not being strictly linear at any instant (10.1016/j.jms.2019.05.005 looks at HCO+). Therefore I do not think it is a significant enough detail in the scope of CO2 topics to mention in the article about this substance. DMacks (talk) 03:04, 7 July 2020 (UTC)
 * I finally decided to leave the “never linear” discussion in this article, since it follows on from the discussion of the vibrational modes which are presented here and not in the Linear molecular geometry article. I have however added some additional explanation. Dirac66 (talk) 21:34, 31 July 2020 (UTC)

Production
The article currently has a section Isolation and production but it's all theoretical.

There are no figures there for the annual production or the means of production. We have them in the relevant articles for all the other main industrial gases I think, but not for CO2.

With the current interest in Carbon dioxide capture you would think these figures would be widely available. Curious. Watch this space. Andrewa (talk) 15:56, 25 January 2021 (UTC)
 * What do you mean by "theoretical"? I see a bunch of incredibly well known and basic chemical reactions that we know to be the physical processes described for things like methane combustion, quicklime production, respiration, etc. This section doesn't seem to be describing anything related to CO2 capture; quite the opposite in fact. Isolation here seems to mean isolation of CO2 from potential sources of it, meaning how to we get CO2. Carbon dioxide capture is about getting rid of CO2 we already have, where isolation and production is about how to get CO2 that you don't have. --OuroborosCobra (talk) 16:11, 25 January 2021 (UTC)
 * By theroretical I mean that this shows how it can be produced (theory) but not how it is being produced (practice).
 * Compare to oxygen One hundred million tonnes of O2 are extracted from air for industrial uses annually by two primary methods. The most common method is fractional distillation of liquefied air... or Hydrogen production or acetylene or ammonia.
 * I think similar data for CO2 would be of great interest. Don't you? Andrewa (talk) 16:30, 25 January 2021 (UTC)

Missing sentence preamble
Hello! On the part directly after the 30th reference or alternatively under the structure and bonding part, I noticed that a sentence is missing the introduction part of the sentence. Since I am currently cramming other tasks, I cannot actively solve it, hence I would only ask for somebody to repair it here. Thanks :D Ice bear johny meowy123 16:01, 10 November 2020 (UTC)
 * That is an unhelpful description. Reference numbers shift, and the "structure and bonding part" is several paragraphs. Instead, you should copy the sentence here. --Hob Gadling (talk) 10:30, 26 January 2021 (UTC)
 * I have now fixed the error. In the paragraph Structure and Bonding, there were apparently two sentences that read: "It has been shown both by theory[29] and by Coulomb explosion imaging experiments.[30] that this is never actually true for both modes at once." The words after [30] appeared to be a sentence fragment. However actually the period after [30] was an error, and the two sentences should only be one sentence. I have removed the extra period. Dirac66 (talk) 12:50, 26 January 2021 (UTC)

Trees
Carbon dioxide removal (CDR), also known as greenhouse gas removal, is a process in which carbon dioxide gas (CO 2) is removed from the atmosphere and sequestered for long periods of time.[1][2][3] These methods are also known as negative emissions technologies, as they offset greenhouse gas emissions from practices such as the burning of fossil fuels.[4]

CDR methods include afforestation, agricultural practices that sequester carbon in soils, bio-energy with carbon capture and storage, ocean fertilization, enhanced weathering, and direct air capture when combined with storage.[2][5][6]To assess whether net negative emissions are achieved by a particular process, comprehensive life cycle analysis of the process must be performed.

Alternatively, some sources use the term "carbon dioxide removal" to refer to any technology that removes carbon dioxide, such as direct air capture, but can be implemented in a way that causes emissions to increase rather than decrease over the lifecycle of the process.

The IPCC's analysis of climate change mitigation pathways that are consistent with limiting global warming to 1.5°C found that all assessed pathways include the use of CDR to offset emissions.[7] A 2019 consensus report by NASEM concluded that using existing CDR methods at scales that can be safely and economically deployed, there is potential to remove and sequester up to 10 gigatons of carbon dioxide per year.[4] This would offset greenhouse gas emissions at about a fifth of the rate at which they are being produced. — Preceding unsigned comment added by 2A02:C7F:72ED:A500:40D1:FB99:1D4B:2986 (talk) 19:43, 20 February 2021 (UTC)


 * Are you suggesting the above paragraphs as a possible addition to the article? They do look interesting, but you will have to add the details of your references [1], [2], ... [7] so that interested readers can actually find them. Also it might be a good idea to specify whether you are thinking of adding this content to a specific section of the article, or starting a new section. Dirac66 (talk) 20:04, 20 February 2021 (UTC)
 * The whole block is just copy-pasted from the lede of Carbon dioxide removal. DMacks (talk) 21:06, 20 February 2021 (UTC)
 * Aha. That is why the references just have numbers and no details. So no, there is no point in copying all 4 paragraphs to this article. What I will do is to add Carbon dioxide removal to the See also list. Dirac66 (talk) 23:35, 20 February 2021 (UTC)

WP:Sandwich
The subsection on Earth's atmosphere now suffers from sandwiching, which is an accessibility issue (and also ugly). I deleted one image to partially fix the issue, and like to start discussion now that @Plantsurfer seems to have a differing opinion on importance. Given the non-negioability of accessibility, I see only a few solutions


 * Remove low-quality image I deleted before: the same information is given in c of the big picture
 * Remove the NASA simulation (=prettiest picture). Even without absorbtion, CO2 is well-mixed in earth's atmosphere, so the false-colour NASA simulation may misinform more than inform.
 * Remove the big picture: it's also not great in resolution, and may be overly detailed.

The Keeling curve is canonical, so should stay. Let me know which solution you prefer. FemkeMilene (talk) 14:25, 20 June 2021 (UTC)
 * It seems like the NASA image is least relevant to our existing article prose. It's also substantially about CO2 absorbance by the oceans, which is the next section of the article, and MOS guideline is that it's better to have an image "too late" than "too soon" vs the article paragraph to which it relates. Further, I don't think this image should be used at all without substantial explanation of what it means. Even reading the image description page, I can't figure out what the color-scale is and whether it is absolute vs relative to today's absorbing capability. That probably makes it all too detailed for this top-level CO2 article. DMacks (talk) 15:07, 20 June 2021 (UTC)


 * WP:SANDWICH makes no mention of accessibility as a basis. Our MOS pages are an interwoven jungle, with some parts affected by others (and changes discussed in one place are not always propagated). Could you point us to a discussion in the ACCESS world where SANDWICH is discussed? Feel free to redirect me to those MOS's talkpages if you like. DMacks (talk) 15:10, 20 June 2021 (UTC)
 * Interesting that accessibility is not mentioned there. It is mentioned here: MOS:ACCIM. FemkeMilene (talk) 15:28, 20 June 2021 (UTC)

Updated values of the triple point, critical point, and vapour pressure; minor grammatical changes; slightly messed-up references (again)
Hello everyone!

I've updated the values of the triple point, critical point, and vapour pressure of carbon dioxide based on this |reference (you can find an accessible version on Semantic Scholar, which is the one I used). I removed the melting point row in the table because I wanted to replace it with the (more accurate? I'm not sure) triple point but then found the parameter wasn't available for Chembox. I've also done a few grammatical fixes at some points to (in my opinion) make the text a bit easier to read.

However, being the newbie that I still am, I've messed up the references for the source linked above AGAIN. Can someone please help fix up the references?

Thanks,

MeasureWell (talk) 04:06, 2 July 2021 (UTC)

One of the fundamental factors in the emergence of life. Forms carbon and water in reaction with methane.
One of the fundamental factors in the emergence of life. Forms carbon and water in reaction with methane. Jacek Wasielewski 2A00:F41:707E:9613:0:25:F40:8F01 (talk) 20:34, 12 February 2022 (UTC)

CO2 is not acidic.
This page is protected so I can’t edit it but it contains a basic error. CO2 is not acidic or an acid in itself so to state so is incorrect. It can form an acid when dissolved in water as the H2O and CO2 combine to form Carbonic Acid. (H2 CO3) 2A00:23C8:821D:3801:64C8:80D8:7107:9DBF (talk) 07:38, 2 May 2022 (UTC)


 * Fixed in intro paragraph. Thank you. Dirac66 (talk) 21:10, 25 May 2022 (UTC)

Lead rewrite for readability and more relevance to a general audience
Hopefully the community considers it a step forward. It is a WP:BOLD edit. The goals I had were:
 * Clarifying how CO2 acts as a greenhouse gas up front
 * Distinguishing between carbon sinks and sequestration
 * Trying to create a more readable flow with fewer disconnected sentences
 * Tightening up the wording and cutting a few bits that I did not think belonged in the lead Efbrazil (talk) 23:31, 31 July 2022 (UTC)

The section "in the oceans" needs work
The section "in the oceans" currently has a lot of quite outdated information on ocean acidification. I plan to remove that and replace it with newer content from the ocean acidification article, an article which has recently been overhauled and updated by me and others. This could be done either by copying sentences across or by using an excerpt from the lead (see WP:excerpt). Since ocean acidification is continually evolving, and getting worse and worse, an excerpt might be better in this case as it means the information only has to be updated in one article, not in several. EMsmile (talk) 11:17, 9 December 2022 (UTC)
 * I've done this work now. I've replaced the existing content (which was mostly outdated with old references) with two excerpts from the ocean acidification article. However, it is not clear to me how much detail we want to provide on the impacts on the calcifying organisms? It's very interesting stuff but maybe it's too much detail for this article? Instead of the excerpts, we could of course also copy the sentences across from ocean acidification - if we feel that the excerpts are too disjointed like this. EMsmile (talk) 21:31, 9 December 2022 (UTC)

Moved history section to the end
I've moved the history section to the end, as I don't think it needs to be the first thing that readers see, after the lead. I compared this article with other articles on chemical elements and gases: some have the history section first, some have it towards the end. So it seems that there is no "standard" for this. Examples: The article on carbon has history somewhere in the middle. Oxygen has it at the start. Hydrogen has it in the second section, nitrous oxide has history in the fifth section. So there is no clear system. I think when it comes to carbon dioxide, the history section does not need to come first as it will only be of interest to "history buffs". I am assuming that most people come to this article to find out what CO2 is and what is going on with the CO2 in our daily lives now and in the future. EMsmile (talk) 21:41, 9 December 2022 (UTC)

Rearranged structure a bit
I've rearranged the structure a bit today. I hope I wasn't too bold but I think it's a more logical flow this way. I've written in the edit summaries an explanation for each change. Please comment here if you disagree with any of those changes or if things need further discussion. EMsmile (talk) 22:22, 9 December 2022 (UTC)

Regarding the section: In Earth's atmosphere
I am planning to do some work on the article carbon dioxide in Earth's atmosphere and was just looking around to see what links to there. This article links to there and actually has a section called "In Earth's atmosphere". In order to reduce repetition and overlap I'd like to suggest that we synchronise the two articles. Perhaps what would work best is to use an excerpt from carbon dioxide in Earth's atmosphere, and to move/merge the existing text from here to there. Otherwise we'd have to update content in two place which would be tedious. EMsmile (talk) 14:11, 26 November 2021 (UTC)
 * What do any of the people watching this page think of my proposal from 26 Nov 21? If no objections, I can try to tackle this soon-ish. EMsmile (talk) 11:22, 22 February 2022 (UTC)
 * Good idea in my opinion and I encourage you to go ahead. Not sure what you mean by using an "excerpt" from carbon dioxide in Earth's atmosphere instead of the present section. Maybe you are thinking of adapting that article's lead for use in this section? In any case, I appreciate the massive effort and skill you have previously put into organizing and improving articles related to climate and the environment. –MadeOfAtoms (talk) 21:09, 22 February 2022 (UTC)
 * WP:excerpt allow you to transclude the same paragraphs in multiple articles. In this case, I'd be okay with it after the lead section is sufficiently improved with citations from this article.
 * Currently, the information of this article seems to be of higher quality. The 'in earths atmosphere' lead is not fully cited, and contains outdated information (the 30-40% again).
 * A complete replacement would reduce the text from 6 to 2 paragraphs. That may be too little in comparison with overview sources? I think the first 5 are valuable. You'll probably want to write at least one more paragraph to better summarise the 'in Earth's atmosphere' article, but making sure there isn't too much overlap with other sections in the current article. A challenge for sure :). Femke (talk) 17:20, 23 February 2022 (UTC)
 * Update: I am coming back to this work now. I am currently reworking carbon dioxide in Earth's atmosphere. Once I'm done with that, I plan to improve this section here, probably by using the excerpt tool from the other article but carefully checking which text block and references are more up to date (the one here or the one there) and then hopefully combining the best content in a clever way. EMsmile (talk) 11:19, 9 December 2022 (UTC)
 * @Femke: I've now removed the sentence with the 30-40% from the lead of the carbon dioxide in Earth's atmosphere article (old sentence was "Between 30% and 40% of the CO2 released by humans into the atmosphere dissolves into the oceans"). I plan on reworking that lead and then checking if it becomes suitable to be an excerpt for here. What did you mean with "I think the first 5 are valuable."? (sorry for asking 10 months later). EMsmile (talk) 12:14, 9 December 2022 (UTC)
 * Another update: I've now copied the text from the section "in Earth's atmosphere" to the lead of carbon dioxide in Earth's atmosphere. There, I have reworked it a bit (some further editing is still needed). After that, I plan to bring it back here by transcribing it in an excerpt. So it means the end result will be rather similar to how it currently looks (about 4-5 paragraphs long; about 500 words) but in future the content would have to be updated in only one article, not in two: Future updates about CO2 in the atmosphere would be made at carbon dioxide in Earth's atmosphere and then automatically be shown here. EMsmile (talk) 12:57, 9 December 2022 (UTC)
 * Update: I've replaced this text with an excerpt, after having moved the text to carbon dioxide in Earth's atmosphere. For now I have taken the entire lead but we could instead only take the first 4 paragraphs for example.EMsmile (talk) 11:55, 12 December 2022 (UTC)

Too many links under See also
Some of the See also links are far too tenuous for the article and need culling. 101.98.39.246 (talk) 20:52, 8 October 2022 (UTC)
 * I agree with you. I've removed some but I think there are still too many. Please go ahead and remove more. EMsmile (talk) 11:13, 9 December 2022 (UTC)


 * I don't bother logging in any more (too many bad editors) and the article is protected. 43.249.196.226 (talk) 06:58, 5 January 2023 (UTC)

Semi-protected edit request on 11 January 2023
The article states in the Photosynthesis section that photosynthesis is used to produce glucose from carbon dioxide. Not quite true. Photosynthesis does not involve carbon dioxide. Light energy capture by chlorophyll is used the create ATP and produces oxygen.

ATP is then used in a separate reaction to fix carbon dioxide.

It's often a school pupil misconception of over simplifying photosynthesis, that has to be unlearnt at later stages of education! 101.53.219.101 (talk) 03:56, 11 January 2023 (UTC)
 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Lightoil (talk) 08:42, 11 January 2023 (UTC)

75 % CO2 only kills insects and small animals?
"At the Bossoleto hot spring near Rapolano Terme in Tuscany, Italy, situated in a bowl-shaped depression about 100 m (330 ft) in diameter, concentrations of CO2 rise to above 75% overnight, sufficient to kill insects and small animals." Is there a decimal point missing or something? Given the other values in the article, like: 7 to 10 % CO2 causing suffocation in humans, I'd expect 75% to have more impact. Samorost1 (talk) 08:11, 1 March 2023 (UTC)

Pop Rocks Section, PSI mismatch.
Under Commercial Uses/Foods the second paragraph mentions Pop Rocks and lists the psi at 580 among other pressure measurements. The Wikipedia page for Pop Rocks says 730 psi. The source article for the information used for CO2 is a magazine article (116) and does not mention the psi measurement. The source for Pop Rocks itself ( Manufacturing ) is the actual patent document (9) describing the process. Respectfully Request to use the Pop Rocks pages psi measurement and more credible source. Omnius (talk) 00:04, 10 July 2023 (UTC)