Talk:Carbon cycle

I am removing this section which was added by a student last year. I don't think this fits in a high level article on the carbon cycle. EMsmile (talk) 12:13, 15 May 2023 (UTC)

Herbivore impacts: Increased herbivore populations can alter the amount of carbon dioxide produced from a ecosystem, overall impacting the carbon cycle. Large mobile herbivores have the ability to alter both the above and below ground composition of a ecosystem, through selective feeding, trampling, and waste, all of which decrease plant production.^[1] Selectively feeding on high quality plants decreases the aboveground plant composition, on the other hand trampling results in soil compaction resulting in higher soil bulk density and less soil oxygen.^[1] The amount of carbon dioxide released back into the atmosphere is increased due to large herbivores waste.^[2] The impact large herbivores have on the ecosystem suggest their importance to the carbon cycle, as with the help of natural disturbances, increased herbivore populations can shift a carbon sink to a source. The boreal forest is a prime example of how increased herbivore populations can negatively impact a ecosystem. Increased herbivore populations significant negative impact on the ecosystem, suggests that they can even be identified as a invasive species.^[3]

EMsmile (talk) 12:13, 15 May 2023 (UTC)

I've removed this further reading list as I don't think that it adds value:

• Appenzeller, Tim (February 2004). "The case of the missing carbon". National Geographic Magazine. (Article about the missing carbon sink.)
• Houghton, R. A. (2005). "The contemporary carbon cycle". In William H Schlesinger (ed.). Biogeochemistry. Amsterdam: Elsevier Science. pp. 473–513. ISBN 978-0-08-044642-4.
• Reichle, David E. (2020). The global carbon cycle and climate change : scaling ecological energetics from organism to the biosphere. Amsterdam, Netherlands. ISBN 978-0-12-821767-2. OCLC 1128830826.{{cite book}}: CS1 maint: location missing publisher (link)
• Janzen, H. H. (2004). "Carbon cycling in earth systems—a soil science perspective". Agriculture, Ecosystems & Environment. 104 (3): 399–417. CiteSeerX 10.1.1.466.622. doi:10.1016/j.agee.2004.01.040.
• Millero, Frank J. (2005). Chemical Oceanography (3 ed.). CRC Press. ISBN 978-0-8493-2280-8.

EMsmile (talk) 12:14, 15 May 2023 (UTC)

I've removed section on chemicals and pollution because I don't think this belongs here. It's about Human impact on marine life and about marine pollution - we have other articles for that. It doesn't really alter the fundamental carbon cycle but is just about pollution. EMsmile (talk) 12:30, 15 May 2023 (UTC)

Man-made chemicals: Smaller amounts of man-made petrochemicals, containing fossil carbon, can have unexpected and outsized effects on the biological carbon cycle. This occurs in part because they have been purposely created by humans to decompose slowly, which enables their unnatural persistence and buildup throughout the biosphere. In many cases their pathways through the broader carbon cycle are also not yet well-characterized or understood.

Plastics:

Close to 400 million tons of plastic were manufactured globally during year 2018 with annual growth rates approaching 10%, and over 6 gigatons produced in total since 1950.^[1] Plastics eventually undergo fragmentation as a typical first step in their decay, and this enables their widespread distribution by air and water currents. Animals easily internalize microplastics and nanoplastics through ingestion and inhalation, accompanied by risks of bioaccumulation. Biodegradable plastics placed into landfills generate methane and carbon dioxide which cycles through the atmosphere unless captured.^[2] A major review of the scientific evidence as of year 2019 did not identify major consequences for human society at current levels, but does foresee substantial risks emerging within the next century.^[3] A 2019 study indicated that degradation of plastics through sun exposure, releases both carbon dioxide and other greenhouse gases.^[4] Bioplastics with a more natural and rapid carbon cycle have been developed as an alternative to other petroleum-based single-use plastics.^[5]

EMsmile (talk) 12:30, 15 May 2023 (UTC)

The lead is currently quite short (only around 200 words) with about half being about the natural cycle and the other half about climate change. I think this balance is a bit off. I suggest the length of the lead should be about doubled, and then about three quarters should explain what the natural carbon cycle is and then one quarter talk about climate change. There were some previous discussions about this as well, see talk page archive here: https://en.wikipedia.org/wiki/Talk:Carbon_cycle/Archive_1#Improve_lead_for_translation?. EMsmile (talk) 13:04, 15 May 2023 (UTC)

I think we should improve the structure a bit. I like the existing section headings called "main components" and "human influence on carbon cycle". But there are these four main headings which are unclear to me. Can they be grouped under a suitable new main heading like "Interactions with other cycles" or "Related systems" or "Types" or anything like that?:

• Terrestrial carbon in the water cycle
• Terrestrial runoff to the ocean
• The ocean biological pump
• Fast and slow cycles

EMsmile (talk) 07:25, 22 May 2023 (UTC)

Yes, I agree. The first three of the four sections you mention above are focused on processes and interactions involved in the fast carbon cycle. The section in the article called "Deep carbon cycle", which immediately follows the ones you mention above, is focused on processes and interactions involved in the slow carbon cycle. These five sections altogether could be reorganised under two main headings, "Fast carbon cycle" and "Slow carbon cycle". — Epipelagic (talk) 10:21, 22 May 2023 (UTC)

Ah, could you please make those changes accordingly? Is this distinction into fast and slow well accepted or are there other ways of categorising this as well? Would it help if we have a new section called "Types" or "Sub-cycles" to explain this? Also, should this section heading be modified: "Main components", i.e. is it main components of fast or slow or both? And the section on human influence: does it then refer to the fast or slow cycle or to both? Sorry if these questions are a bit daft; think of me as a typical clue-less reader of this Wikipedia article. :-) (does something equivalent also apply to the water cycle?). EMsmile (talk) 10:31, 22 May 2023 (UTC)

The section "main components" might be better titled "main compartments", as they are referred to in biogeochemical cycle. This section is focussed on the physical parts of the earth where the cycling takes place, and is a more like a static map of where different things happen. The following sections involving the fast and slow cycles are more focussed on the dynamics of what is happening, the mechanics of the processes and interactions involved. The section "human influence on carbon cycle" is more concerned with the fast cycle, since we are naturally more worried by what happens over the next hundred years than the next million years. But finding ways to move carbon into the slow cycle might well be a solution we are looking for. — Epipelagic (talk) 11:10, 22 May 2023 (UTC)

Thanks, this made it a lot clearer for me. I've now made some changes to the section headings accordingly, can you please check if you agree with how I have changed it (or improve/correct what I've done)? Thanks a lot. EMsmile (talk) 11:40, 22 May 2023 (UTC)

The terms "fast carbon cycle" and "slow carbon cycle" are helpful as descriptive terms when it comes to organising the layout of this article, but I'm not sure they should be highlighted in the article so much. The terms are used in the academic literature, but not so widely as to justify this much use in the article. I added more sources and (later) will tone down the emphasis in the article. — Epipelagic (talk) 01:39, 23 May 2023 (UTC)

Thank you for this clarification, Epipelagic. That's very useful. Are you happy with the way these terms are used and explained in the article now or would you prefer to see further changes? What about the article and its structure overall, is it OK like this now or does it have specific weaknesses? EMsmile (talk) 13:25, 13 June 2023 (UTC)

I don't understand why this section "Terrestrial carbon in the water cycle" starts with this sentence: "In the diagram on the right:". What is it trying to say? Is it trying to say "The terrestrial carbon in the water cycle includes:"? EMsmile (talk) 07:27, 22 May 2023 (UTC)

I've now changed it to: "The movement of terrestrial carbon in the water cycle is shown in the diagram on the right and explained below" EMsmile (talk) 11:39, 22 May 2023 (UTC)

1."Halocarbons are less prolific compounds developed for diverse uses throughout industry; for example as solvents and refrigerants. Nevertheless, the buildup of relatively small concentrations (parts per trillion) of chlorofluorocarbon, hydrofluorocarbon, and perfluorocarbon gases in the atmosphere is responsible for about 10% of the total direct radiative forcing from all long-lived greenhouse gases (year 2019); which includes forcing from the much larger concentrations of carbon dioxide and methane.", 2.Ocean, including dissolved inorganic carbon and living and non-living marine biota. Can anybody help? Thanks.ThomasYehYeh (talk) 13:26, 7 December 2023 (UTC)

I also don't understand this. I guess it's related to radiative forcing, perhaps that article explains it? If not, you could try to ask on the talk page of WikiProject climate change. EMsmile (talk) 15:40, 31 December 2023 (UTC)

This article was the subject of a Wiki Education Foundation-supported course assignment, between 26 August 2024 and 13 December 2024. Further details are available on the course page. Student editor(s): OmarThePhilosopher (article contribs).

— Assignment last updated by OmarThePhilosopher (talk) 18:15, 16 September 2024 (UTC)

The table next to Carbon cycle#Ocean lists for fossil fuels the following storage sizes:

• 4,130 Gt C Fossil fuels (total)
  • 3,510 Gt C Coal
  • 230 Gt C Oil
  • 140 Gt C Gas
  • 250 Gt C Other (peat)

I believe this must be the estimation of resources (what is assumed to be there) and not of the reserves (what is assumed to be mineable with current technology at current prices). In 2019, the BGR did sum up in their Energy Study not only the estimates for reserves and resources, but also added for fossil fuels the CO₂ emission potential. See Table 4 at page 41.

The number of 4000 Gt seems to be by a factor of 4 too large (reserves) or by a factor of 3 too small (resources). Has somebody access to the quoted Science paper from 2000 and can have a look where the numbers are coming from? Are there other sources available which give an overview on carbon pool sizes? I strongly believe that resource estimations should match with the fossil fuel pool in carbon cycle assessments. --Gunnar (talk) 21:07, 21 February 2025 (UTC)