Talk:Carbonate–silicate cycle

SiO^2-
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Article Silicate doesn't say a word about that. Kaligula (talk) 19:45, 29 November 2012 (UTC)

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Structural Critiques and Questionable Citations

Hello all,

I think that this article has set out a fact-dense foundation for the topic of carbonate-silicate weathering. However, some structural revision may help it flow better for those who are not very familiar with the topic. I offer 3 suggestions:

The 3rd paragraph feels like an enhanced version of the first paragraph. These two could possibly be married and, together, form the article's lead section.

I've tried to combine/expand on these sections in the overview. Hope you think it helps Gretashum (talk) 06:56, 13 June 2019 (UTC)

The 2nd paragraph describing the chemical reactions of this phenomenon warrants a sub-heading to let the reader digest this topic and its varying complexity in this short article.

I did not add a subheading because I think breaking it down into stages is enough. Since there are only a few primary reactions I don't think the chemical reactions necessarily warrant their own section, but if you still think they should be broken up, I think it would be easy enough to take what I've outlined and separate it out Gretashum (talk) 06:56, 13 June 2019 (UTC)

Lastly, the Venus fact at the bottom could also be given a sub-heading as it does not pertain to Earth.

The section at the bottom is now all about non-Earth planets. Have added information about Mars, in addition to Venus Gretashum (talk) 06:56, 13 June 2019 (UTC)

Most of the references (4/6) are solid. Reference No. 2, however, is a professor's lecture notes from a Washington state university. The professor's email is provided at the bottom of that page but other than that there is no formal reference or in-text citations within these lecture notes to denote where these "facts" were obtained from. I'd also like to direct your attention to an external citation update that was contributed by another user and can be found above. This page offers a simple sequence of events that describe parts of the carbon cycle but with no reference in sight.

I think the idea with this reference was to comprehensively sort of cite the papers that are listed at the bottom of this page. I've removed this url as a reference and now point directly to the individual papers they should point toward Gretashum (talk) 06:56, 13 June 2019 (UTC)

I think that this article could be fantastic and with some more diligent digging for sources on the carbon cycle and carbonate-silicate weathering and thoughtful narration it can get there! Cshields94 (talk) 20:29, 24 April 2017 (UTC)

It'll get there Gretashum (talk) 06:56, 13 June 2019 (UTC)

Critiques Regarding the Article and Proposed Solutions

The article seems to have a very informative opening with good information to introduce the Carbonate-Silicate Cycle. It gives characteristic description of the Carbonate-silicate cycle as well as relay the cycle's role in the global carbon cycle. Aside from the more worded descriptions of the cycle, it also gives the chemical reactions that take place and explains what minerals are involved and the conditions of which the scenario needs to be in. The format of the article could use some work, the entire article is basically one large paragraph which is a lot for the eyes. Overall, content is good to start with, the article needs to be reformatted with alterations completed on sources and content displayed.

Some solutions could be to begin separating the information into sections such as "description", "chemical process", etc. Also there is a sentence at the end of the article regarding cycles on Venus, which I think is very cool and should be in its own section (ie: "Cycle on Other Planets").

Finally, as stated before in the talk above mine, a couple of the sources could be cleaned up a bit or resourced while still keeping the information.

As mentioned before by other users, this article has potential and I'm looking forward to helping contribute! Twright71 (talk) 03:24, 5 September 2018 (UTC)

New Bibliography

Batalha, Natasha; Kumar Kopparapu, Ravi; Haqq-Misra, Jacob; Kasting, James F. (2016) .“Climate cycling on early Mars caused by the carbonate–silicate cycle”. Earth and Planetary Science Letters: 455: 7 -13. https://doi.org/10.1016/j.epsl.2016.08.044

Berner, Robert A. (1992). “Weathering, plants, and the long-term carbon cycle”. Geochimica et Cosmochimica Acta: 56(8): 3225 -3231. https://doi.org/10.1016/0016-7037(92)90300-8

Ittekkotc, Venugopalan; Humborg, Christoph; Schäfer, Petra (2000). “Hydrological Alterations and Marine Biogeochemistry: A Silicate Issue?: Silicate retention in reservoirs behind dams affects ecosystem structure in coastal seas”. BioScience: 50(9): 776-682. https://doi.org/10.1641/0006-3568(2000)050%5B0776:HAAMBA%5D2.0.CO;2

Raymo, Maureen E.; Ruddiman, William F.; Froelich, Phillip N. (1988). “Influence of late Cenozoic mountain building on ocean geochemical cycles”. Geology: 16(7): 649-653. https://doi.org/10.1130/0091-7613(1988)016<0649:IOLCMB>2.3.CO;2

Ridgwell, Andy; Zeebe, Richard E. (2005).“The role of the global carbonate cycle in the regulation and evolution of the Earth system”. Earth and Planetary Science Letters: 234(3-4): 299-315. https://doi.org/10.1016/j.epsl.2005.03.006

Twright71 (talk) 02:25, 19 September 2018 (UTC)

Shellfish calcification...

Are we sure this is the correct chemical reaction for shellfish calcification?

Ca⁺² + 2 HCO₃^- ==> CaCO₃ + CO₂ + H₂O

Because I've got:

[1] In-vivo: HCO₃^- (bicarbonate ion) ==> CO₃^-2 (carbonate ion) + H⁺ (hydrogen ion)

[2] In-vivo: CO₃^-2 (carbonate ion) + Ca⁺² (calcium) ==> CaCO₃ (calcium carbonate)

[3] In-vivo, then excreted: H⁺ (hydrogen ion, from [1]) + H₂O (water) ==> H₃O⁺ (hydronium)

[4] Aqueous: H₃O⁺ (hydronium, from [3]) + CO₃^-2 (carbonate ion) ==> H₂CO₃ (carbonic acid) + OH^- (hydroxide)

[5] Aqueous: H₂CO₃ (carbonic acid, from [4]) ==> H⁺ (hydrogen ion) + HCO₃^- (bicarbonate ion)

[6] Aqueous: OH^- (hydroxide, from [4]) + H⁺ (hydrogen ion, from [1] or [5]) ==> H₂O (water)

The reason I ask:

https://www.whoi.edu/oceanus/feature/how-do-corals-build-their-skeletons/

"They pump hydrogen ions (H⁺) out of this space to produce more carbonate ions (CO₃^2-) ions that bond with (Ca²⁺) ions to make calcium carbonate (CaCO₃) for their skeletons."

Of course, they have to toe the alarmist line that rising CO₂ will make it harder for coral and mollusks:

"Because there are more HCO₃^- ions but fewer CO₃^2- ions in acidified seawater, the corals have to expend more energy to pump out H⁺ ions from their calcifying space to build skeletons."

Except there are no coral or mollusk taxa which utilize carbonate transporters... no carbonate transporters have been found. Only bicarbonate transporters have been found. So their explanation as to why a rising CO₂ concentration will make the coral and mollusks "expend more energy" to expel H⁺, rather than just using carbonate directly, is fictional alarmist bafflegab.

So those mollusks and corals always were "expending more energy" to expel H⁺, and an increasing bicarbonate concentration due to a rising atmospheric CO₂ concentration will make it easier for them to undergo calcification at a faster rate.

They evolved during the Cambrian Explosion, when CO₂ concentration was many times higher than today, so it stands to reason that they would use bicarbonate transporters, not carbonate transporters (carbonate practically disappears at ~pH 6). Calcification today is rate-limited because atmospheric CO₂ concentration is near historic lows, so bicarbonate concentration is comparatively low.

Likewise, this paragraph:

"Human emissions of CO₂ have been steadily increasing, and the consequent concentration of CO₂ in the Earth system has reached unprecedented levels in a very short amount of time.[23] Excess carbon in the atmosphere that is dissolved in seawater can alter the rates of carbonate-silicate cycle. Dissolved CO₂ may react with water to form bicarbonate ions, HCO₃⁻, and hydrogen ions, H⁺. These hydrogen ions quickly react with carbonate, CO₃^2- to produce more bicarbonate ions and reduce the available carbonate ions, which presents an obstacle to the carbon carbonate precipitation process.[24] Put differently, 30% of excess carbon emitted into the atmosphere is absorbed by the oceans. Higher concentrations of carbon dioxide in the oceans work to push the carbonate precipitation process in the opposite direction (to the left), producing less CaCO₃. This process, which harms shell-building organisms, is called ocean acidification.[25]"

... should be removed. It is diametrically opposite to empirical reality. There are no coral or mollusk taxa which use carbonate transporters. All transporters discovered to date are bicarbonate transporters.

76.30.103.137 (talk) 04:08, 17 November 2024 (UTC)