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This article is written in American English, which has its own spelling conventions (color, defense, traveled) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.

	Carbon dioxide was one of the 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 Date Process Result December 10, 2005 Good article nominee Listed July 30, 2006 Peer review Reviewed April 24, 2007 Good article reassessment Delisted This article was on the Article Collaboration and Improvement Drive for the week of July 11, 2007. Current status: Delisted good article

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Chemicals: Core Top‑importance This article is within the scope of WikiProject Chemicals, a daughter project of WikiProject Chemistry, which aims to improve Wikipedia's coverage of chemicals. To participate, help improve this article or visit the project page for details on the project.ChemicalsWikipedia:WikiProject ChemicalsTemplate:WikiProject Chemicalschemicals Top This article has been rated as Top-importance on the project's importance scale. This is a core article in the WikiProject Chemicals worklist. Environment High‑importance This environment-related article is part of the WikiProject Environment to improve Wikipedia's coverage of the environment. The aim is to write neutral and well-referenced articles on environment-related topics, as well as to ensure that environment articles are properly categorized. Read Wikipedia:Contributing FAQ and leave any messages at the project talk page.EnvironmentWikipedia:WikiProject EnvironmentTemplate:WikiProject EnvironmentEnvironment High This article has been rated as High-importance on the project's importance scale. Occupational Safety and Health Low‑importance This article is within the scope of WikiProject Occupational Safety and Health, a collaborative effort to improve the coverage of articles related to occupational safety and health on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Occupational Safety and HealthWikipedia:WikiProject Occupational Safety and HealthTemplate:WikiProject Occupational Safety and HealthOccupational Safety and Health Low This article has been rated as Low-importance on the project's importance scale. Volcanoes Mid‑importance This article is within the scope of WikiProject Volcanoes, a collaborative effort to improve the coverage of volcanoes, volcanology, igneous petrology, and related subjects on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.VolcanoesWikipedia:WikiProject VolcanoesTemplate:WikiProject VolcanoesWikiProject Volcanoes Mid This article has been rated as Mid-importance on the project's importance scale. Climate change High‑importance This article is within the scope of WikiProject Climate change, a collaborative effort to improve the coverage of Climate change on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Climate changeWikipedia:WikiProject Climate changeTemplate:WikiProject Climate changeClimate change High This article has been rated as High-importance on the project's importance scale. If you are looking for ways to improve this article, we recommend checking out our recommended sources and our style guide

To-do list for Carbon dioxide: edit · history · watch · refresh · Updated 2024-10-30 Here are some tasks awaiting attention: Cleanup : *More and better references (more print references needed) Use a consistent style of referencing (inline seems the best) Tidy up external links Expand : *On other planets (e.g. Venus) More on plants (Mainly their carbon fixation e.g. CAM, C4 plants) More on past levels of CO2 and how they changed (e.g. earth's early atmosphere, the role of cyanobacteria) Write a full lead section when finished (~3 paragraphs) Verify : Verify disputed claims and statistics From ACID nomination: Vital topic for any encyclopaedia, but is in poor shape. Pending a split, and has several lists of things that need doing, if anyone is interested? — Jack · talk · 06:08, Wednesday, 25 April 2007 Especially with all of the discussion of it in Global Warming contexts recently. ~ BigrTex 14:58, 3 May 2007 (UTC) Way too long "see also" list, should and could be incorporated into prose. Punkmorten 13:32, 18 May 2007 (UTC) The Fire Extinguisher Entry is outdated and wrong. CO2 IS toxic at concentrations higher than 5%. Design Concentrations for Room Flooding systems with CO2 are 40%+ so CO2 is not suitable for occupied spaces. CO2 Flooding Systems are not supported for use in occupiable spaces though many countries such as USA and other third world countries still misuse CO2 in Fire Suppression Systems because it is cheap. The NFPA supports the use of CO2 on electrical hazards though it is not supported globally because CO2 can cause over pressurization, thermal shock, electrical component damage and has human health/toxicity issues. The NFPA organisation is not the definitive word/authority on Fire Suppression it is just one of many organisations involved in making standards for Fire Protection. The NFPA is really relevent only to the USA. USA codes and standards are typically only relevent to the USA so should not be referenced as the main global Fire standard on a site like wiki which serves a global audience (unless wiki is only for Americans). Though CO2 was used many years ago to protect enclosed spaces on Ships, this is extremely outdated. CO2 has caused fatalities on ships in Navies and merchant fleets that it is now superceded in this application by using extinguishants that support human life at design concentrations such as HFC-227 or Novec-1230. Unlike other countries, America and other third world countries still allow the use of CO2 in some applications where humans can be present because CO2 is cheap and installations are not monitored/controlled. (~GRANT) — Preceding unsigned comment added by 81.140.155.66 (talk • contribs) 10:19, 2 December 2009 (UTC)

The contentious topics procedure applies to this page. This page is related to climate change, which has been designated as a contentious topic. Editors who repeatedly or seriously fail to adhere to the purpose of Wikipedia, any expected standards of behaviour, or any normal editorial process may be blocked or restricted by an administrator. Editors are advised to familiarise themselves with the contentious topics procedures before editing this page.

There are many data with ambiguous units of measurement like "ppm" and "%" across this article (and many other articles across Wikipedia), without a clear explanation what those units stand for. Without a clear explanation, those units can stand for mass per volume, volume per volume, mole per mole or who knows what else. Can someone clarify what those units stand for, despite that is not clarified in the sources? The data about the concentrations of carbon dioxide (and other suffocating and toxic gases and substances) in the air, water, food, drinks, products, etcetera, is a very important information for readers, especially non-expert ones, so, editors should be notified about the very existence of the ambiguous "ppm", "%" and similar ambiguous units across Wikipedia. Let's discuss. I am opening a debate. What do you think? Do you agree or disagree with me, and explain why. Thanks in advance for your opinion. Bernardirfan (talk) 18:08, 30 August 2023 (UTC)[reply]

WP:JUSTFIXIT with a WP:SCIRS source. Zefr (talk) 19:06, 30 August 2023 (UTC)[reply]

I think another editor has now fixed the problem. Thanks for pointing it out. Not everything needs a debate, as Zefr rightly points out. Qflib, aka KeeYou Flib (talk) 14:09, 6 September 2023 (UTC)[reply]

Thank you Qlib and Zefr for resolving my {{clarify}} tags. Bernardirfan (talk) 09:41, 16 October 2023 (UTC)[reply]

I removed the following content that is unsourced. All biomedical claims need WP:MEDRS sourcing because we don't want people to harm themselves. Clayoquot (talk | contribs) 00:46, 30 October 2024 (UTC)[reply]

In medicine, up to 5% carbon dioxide (130 times atmospheric concentration) is added to oxygen for stimulation of breathing after apnea and to stabilize the O₂/CO₂ balance in blood.

Carbon dioxide can be mixed with up to 50% oxygen, forming an inhalable gas; this is known as Carbogen and has a variety of medical and research uses.

Another medical use are the mofette, dry spas that use carbon dioxide from post-volcanic discharge for therapeutic purposes.

The article currently gives a lot of weight to the use of CO2 in the food and beverage industries and various industrial niches. These are relatively small uses of CO2, which is primarily used in urea production and in the oil and gas industry or not used at all. I plan to update it to give a more balanced overview of commercial use. To replace the last paragraph of the lead, I have drafted the following text (adapted largely from the IEA, CC-BY):

Globally, 230 million tonnes (Mt) of carbon dioxide (CO2) are used every year. The largest consumer is the fertilizer industry, where 130 Mt CO2 is used in urea manufacturing.^[1]: 3 The oil and gas industry consumes 70 to 80 Mt CO2 annually for enhanced oil recovery.^[1]: 3 Other commercial applications include food and beverage production, metal fabrication, cooling, fire suppression and stimulating plant growth in greenhouses. ^[1]: 3 Some usage of CO2 results in long-term sequestration underground or in products. However, as the the potential for commercial use of CO2 is relatively small, the vast majority of CO2 is a waste product.^[2]

Clayoquot (talk | contribs) 21:38, 30 October 2024 (UTC)[reply]

I've removed the content below from the "Commercial uses" section as they describe technologies that are still at pre-commercial stages of development (or possibly at extremely early commercial deployment if I've missed a recent update). The older predictions of glory have not gone anywhere. Recent sourcing on these issues: Allam cycle [1][2], enhanced coal bed methane recovery[3], algal biofuels.[4] Clayoquot (talk | contribs) 18:54, 1 November 2024 (UTC)[reply]

Supercritical CO₂ is used as the working fluid in the Allam power cycle engine.

In enhanced coal bed methane recovery, carbon dioxide would be pumped into the coal seam to displace methane, as opposed to current methods which primarily rely on the removal of water (to reduce pressure) to make the coal seam release its trapped methane.^[3]

It has been proposed that CO₂ from power generation be bubbled into ponds to stimulate growth of algae that could then be converted into biodiesel fuel.^[4] A strain of the cyanobacterium Synechococcus elongatus has been genetically engineered to produce the fuels isobutyraldehyde and isobutanol from CO₂ using photosynthesis.^[5]

Researchers have developed an electrocatalytic technique using enzymes isolated from bacteria to power the chemical reactions which convert CO₂ into fuels.^[6][7][8]

The table in the "Below 1%" section lists a concentration of "700 ppm" with the note "ASHRAE recommendation", but the linked source says (my emphasis)—

Thus, maintaining a steady-state CO2 concentration in a space no greater than about 700 ppm above outdoor air levels will indicate that a substantial majority of visitors entering a space will be satisfied with respect to human bioeffluents (body odor).

So, the ASHRAE recommendation isn't "700 ppm", but rather "700 ppm above outdoor air levels". The table as-written is incorrect. 73.171.45.17 (talk) 20:07, 7 December 2024 (UTC)[reply]