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I'm assuming this article is referring to removal of CO2 from the atmosphere and not directly from the ocean itself? There have been proposals to remove dissol

I'm assuming this article is referring to removal of CO2 from the atmosphere and not directly from the ocean itself? There have been proposals to remove dissolved CO2 directly from the ocean by turning it into calcium carbonate: https://www.smithsonianmag.com/innovation/combat-climate-change-researchers-want-to-pull-carbon-dioxide-from-ocean-and-turn-it-into-rock-180977903/ https://www.smithsonianmag.com/innovation/combat-climate-cha...

frazbin 5y ago
Yeah I wondered the same thing. I suspect that it has a part to play at least. There are a lot (LOT) of pretty pure magnesium/iron silicate minerals in the crust (olivine) that can be ground up and reacted with co2 dissolved in seawater to give magnesium/iron carbonate. Check these folks out: https://www.projectvesta.org/ https://www.projectvesta.org/
- nomel 5y ago
  Off topic, but that page makes me dizzy.
foerbert 5y ago
Yes that seems to be the case, but I'm not sure that actually matters here. The timescales involved mean that there is plenty of time for carbon to move between air and water. The only factor of much importance here would be the overall amount of CO2 removed. There might be some small time savings removing it directly from the ocean, but at 700 years out even 25 gigatons a year of carbon removal was insufficient. Given that kind of time scale, a few years earlier or later wouldn't matter.
- pigeonhole123 5y ago
  It used to be more energy efficient to take dissolved CO2 out of water instead of air. Not sure whether or not that’s still true.
revscat 5y ago
> I’m assuming Literally the first two sentences of TFA address this.
- macawfish 5y ago
  I actually did see the word "atmosphere" in there before I wrote this, believe it or not. But my confusion still stands and is "does this change if the CO2 is extracted directly from the ocean?" I think the article could be much more explicit in this regard... It seems like this study is specifically about the time it will take to for CO2 dissolved in the ocean to evaporate out into an atmosphere which has had CO2 removed, but I can't tell because of how it's worded. I will go look for the original study.
specialist 5y ago
Neat. Great share, thanks. FWIW, that's a reprint of this OC [0]: https://www.hakaimagazine.com/news/petrifying-climate-change/ https://www.hakaimagazine.com/news/petrifying-climate-change... [2021/06/03] TLDR: Uses electrolysis to extract calcium and magnesium from ocean water, which can then be used to extract carbon from atmosphere. Happy by product is hydrogen. Question: This is similar to the desalination systems, right? Can future infrastructure do both? One plausible scenario is to have off shore wind and solar farms powering these devices. Drop the limestone into the ocean. Pipe fresh (treated) water back to shore. Bottle up the H2 for collection. What could be easier? [0] It KILLS ME when articles omit meta data like timestamps, bylines, links to legislation being discussed, etc.

frazbin 5y ago

Yeah I wondered the same thing. I suspect that it has a part to play at least. There are a lot (LOT) of pretty pure magnesium/iron silicate minerals in the crust (olivine) that can be ground up and reacted with co2 dissolved in seawater to give magnesium/iron carbonate. Check these folks out: https://www.projectvesta.org/ https://www.projectvesta.org/

nomel 5y ago
Off topic, but that page makes me dizzy.

foerbert 5y ago

Yes that seems to be the case, but I'm not sure that actually matters here. The timescales involved mean that there is plenty of time for carbon to move between air and water. The only factor of much importance here would be the overall amount of CO2 removed. There might be some small time savings removing it directly from the ocean, but at 700 years out even 25 gigatons a year of carbon removal was insufficient. Given that kind of time scale, a few years earlier or later wouldn't matter.

pigeonhole123 5y ago
It used to be more energy efficient to take dissolved CO2 out of water instead of air. Not sure whether or not that’s still true.

revscat 5y ago

> I’m assuming Literally the first two sentences of TFA address this.

macawfish 5y ago
I actually did see the word "atmosphere" in there before I wrote this, believe it or not. But my confusion still stands and is "does this change if the CO2 is extracted directly from the ocean?" I think the article could be much more explicit in this regard... It seems like this study is specifically about the time it will take to for CO2 dissolved in the ocean to evaporate out into an atmosphere which has had CO2 removed, but I can't tell because of how it's worded. I will go look for the original study.

specialist 5y ago

Neat. Great share, thanks. FWIW, that's a reprint of this OC [0]: https://www.hakaimagazine.com/news/petrifying-climate-change/ https://www.hakaimagazine.com/news/petrifying-climate-change... [2021/06/03] TLDR: Uses electrolysis to extract calcium and magnesium from ocean water, which can then be used to extract carbon from atmosphere. Happy by product is hydrogen. Question: This is similar to the desalination systems, right? Can future infrastructure do both? One plausible scenario is to have off shore wind and solar farms powering these devices. Drop the limestone into the ocean. Pipe fresh (treated) water back to shore. Bottle up the H2 for collection. What could be easier? [0] It KILLS ME when articles omit meta data like timestamps, bylines, links to legislation being discussed, etc.