If the oceans die, its very likely that many or even most humans will also. As a human I am pretty strongly opposed to dying, but thats just, like, my opinion man.
If, theoretically, you could produce hydrocarbons from the carbon dioxide that is currently in our atmosphere, then it could be a substantial reduction in net carbon dioxide being added; and it would be compatible with the fuel infrastructure of today.
The bind moggles.
2.5 billion years ago the earth would have been uninhabitable to most modern life. Single celled life evolved in those conditions and began creating glucose and oxygen from CO2 and water. When those primitive lifeforms died some of them became oil and the CO2 was sequestered.
Over time the CO2 levels dropped until about 20 million years ago the CO2 levels fell to about 300ppm. That's when life as we know it really took off. Yes, it took BILLIONS of years to get there.
Humans have only existed for about 200k years. During that time our CO2 levels have mostly been below about 280ppm. The are now at 429ppm and are rising exponentially. [0]
In time, the oceans have become less and less acidic, by dissolving from the volcanic silicate rocks the oxides of the alkaline metals and alkali earth metals, i.e. mainly of sodium, potassium, magnesium and calcium. This dissolution has affected both the rocks on the bottom of the oceans and the continental rocks, where rain has washed the soluble oxides, transporting them through rivers to the oceans.
At some point, so much of the alkaline and alkali earth metals from the volcanic rocks have been dissolved that the oceans have become slightly alkaline instead of acidic, like they are today.
At that time, the carbonates of calcium and magnesium have precipitated from sea water, forming sedimentary rocks. Also around that time, many living beings have evolved mechanisms for controlling this precipitation process, in order to build skeletons for themselves. This has resulted in the fact that many sedimentary rocks are not formed by direct precipitation from sea water, but by precipitation from sea water into skeletons, followed by depositing on the bottom the skeletons of dead living beings.
Now, with increasing concentration of CO2, there is the danger that the oceans will become so acidic as to reverse this, dissolving again a part of the carbonate rocks, including the skeletons of many living beings that are made of carbonates.
There is an equilibrium between the concentration of CO2 in water and in air, depending on temperature and pressure. When the CO2 from water precipitated with calcium or magnesium into rocks, that has drawn more CO2 from air into the water, until a new equilibrium was reached, at a reduced concentration of CO2 in the air. If carbonates would be dissolved by acidic sea water, that would liberate CO2, a part of which would go into the air, further increasing the concentration there.
Thus the formation or destruction of carbonate rocks and skeletons adds a positive feedback to the changes of the CO2 concentration in the air, which has the potential to be bad for us.
Even worse is the fact that this is only one of multiple positive feedback mechanisms that can be triggered by changes in the CO2 concentration in the air, which make very difficult or impossible any long term predictions.
adrian puts it quite well though.
Keeping that in mind;
>What role, if any, did carbonate mineral formation have in sequestering carbon dioxide from the atmosphere?
Looks like as much as it possibly could.
I get the idea that the throwaway account was suggesting we can just "do whatever forever" without consequences though, and that's just not true. Most CO2 sequestration on earth is now biological in origin and has been for a very long time.
Fischer-Tropsch and Sabatier process can both operate with scavenged CO2. There's been some work since the 1990s utilising seawater as a CO2 source, with CO2 capture being far more efficient than from atmospheric sources.
Whilst hydrocarbons have numerous downsides (whether sourced from fossil or renewable sources), they are also quite convenient, exceedingly well-proven, and tremendously useful. In some applications, particularly marine and aviation transport, there are few if any viable alternatives.
I've commented on this numerous times at HN over the years: <https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...>.
The Sabatier process looks like it might have much less of that! Very cool stuff. I would love to see a future in which we use uninhabitable, non-arable, desert land to generate cheap synfuel that we can ship wherever needed.
While now the cheapest way is to make syngas from methane or from coal, it is possible to make syngas from carbon dioxide that reacts with electrolytic hydrogen.
It is also possible to make equivalent precursors of synthetic hydrocarbons by the electrolysis of carbon dioxide in water.
For these 2 methods, you do not need any fossil fuels, but only electrical energy for electrolysis.
Where the energetic efficiency is still very low is when you want to use clean air as the source of CO2, instead of using a concentrated source of CO2. With very cheap energy, i.e. solar energy that is used at the point of capture, it should still be possible to devise a method of capture for CO2 from the air. Many such methods are known, their only problem being a high energy consumption per the amount of captured CO2, so they are impractical with energy that must be bought from the grid, but I do not see why they could not work when coupled directly with solar panels.
The latter might come from an existing hydrocarbon (as with so-called "blue", "grey", "black", or "brown" hydrogen), or from electrolysis, which is not carbon-neutral. If the latter is powered by a carbon-neutral source (surplus renewables, nuclear), it's "green", and carbon-neutral.
CO2 can also be obtained from numerous sources. One prospect suggested when US peak oil was a concern, in the 1960s, was limestone. More recently, the US Naval Research Lab, as well as Google's Project Foghorn, looked at separating CO2 (in the form of carbonic and carbolic acid) from seawater, which is far less energy intensive than direct removal from the atmosphere. I'd looked up the history of research and industrial applications circa 2014, noted here:
<https://web.archive.org/web/20170719101136/https://www.reddi...>
<https://web.archive.org/web/20230601122020/https://old.reddi...>
The US Navy has an interest largely for its carrier fleet. Whilst the carriers themselves are nuclear powered, their aircraft are not, and fuel provisioning for the aircraft fleets is a major logistical hurdle as well as a strategic vulnerability. No need to target the carriers themselves (heavily defended) if the supply tankers can be sunk, something present US adversaries might consider. One prospect would be to effectively recommission older carriers as fuel-synthesis platforms, capable of producing aviation fuel from seawater in situ and not having to transit between fuel depots and the fleet itself. Given the additional costs of transit and strategic significance, the economics should be somewhat more favourable than for civilian use. This was the subject of a number of papers published in the 2010s by the US Naval Research Laboratory (listed above). Earlier research based on other carbon sources was performed at MIT and Brookhaven National Laboratory in the 1970s and 1960s, respectively.
There’s more of it now than in the reefs recorded history.
Well, 2022 data:
https://www.aims.gov.au/information-centre/news-and-stories/...
While the recovery we reported last year was welcome news, there are challenges ahead. The spectre of global annual coral bleaching will soon become a reality."
This article also mentions that a recent large recovery was due to el nino conditions
"Great Barrier Reef was reeling from successive disturbances, ranging from marine heatwaves and coral bleaching to crown-of-thorns starfish outbreaks and cyclone damage, with widespread death of many corals especially during the heatwaves of 2016 and 2017.
Since then, the Reef has rebounded. Generally cooler La Niña conditions mean hard corals have recovered significant ground, regrowing from very low levels after a decade of cumulative disturbances to record high levels in 2022 across two-thirds of the reef."
Not sure if you were trying to imply some long term recovery or that global warming didn't hurt it because the article says heatwaves were part of a many other conditions that caused massive damage
Don’t Panic.
Everything is O.K.
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Edited to add: Rate limited so can’t reply without creating more alt accounts than I’m willing to, so:
@Timon3 - that’s actually a really good point, and I follow at least a few folk that could be categorised as such at least some of the time.
[0] https://www.politico.com/news/2024/05/09/trump-asks-oil-exec...
It's possible for information to be factual and opinions to be justified from a source while that source also benefits from the information/opinions existing.
I can easily provide counter examples from countless situations that occur each year.
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If you feel that all scientists and researchers have a lower level of trust because of negative actions of some, that's wrong of course because their reputations aren't connected, but you try to confirm it. For example, find out if a cooler than normal El Nino season would help coral feeds (or whatever)
What you did was tell us you don't trust the information, not because of something specific, but a concept/rule you believe.
Considering you originally misrepresented their findings, perhaps by accident, you should have done more to make your case.
https://www.theguardian.com/environment/2025/oct/13/coral-re...