[freebeard]

I pinkie-swear.

To store CO2, it's usually compressed into a liquid form or bonded with water, and then injected deep underground. There, it interacts with basalt rock and solidifies into a carbonate mineral, reportedly in as little as two years.

https://en.wikipedia.org/wiki/Biorock

https://en.wikipedia.org/wiki/Wolf_Hilbertz

Biorock technology arose from experiments in the 1970s when Hilbertz was studying how seashells and reefs grow, by passing electric currents through salt water. In 1974, he found that as the salt water electrolyzes, calcium carbonate (aragonite) combines with magnesium, chloride and hydroxyl ions to slowly accrete around the cathode, eventually coating the electrode with a material similar in composition to magnesium oxychloride cements and as strong as concrete. Over time cathodic protection replaces the negative chloride ion (Cl-) with dissolved bicarbonate (HCO3-) to harden the coating to a hydromagnesite-aragonite mixture with gaseous oxygen evolving through the porous structure. Later experiments showed that the coatings can thicken at the rate of 5 cm per year. As long as current flows, the structure continues to grow and strengthen. It can heal itself if damaged, making it particularly useful as a replacement for concrete in hard-to-access locations. High levels of dissolved oxygen make it particularly attractive to marine organisms, particularly fin fish.

Hilbertz originally called his invention, on which he obtained several patents, underwater mineral accretion or accretion for short. Hilbertz’s original plan was to use this technology to grow low-cost structures in the ocean for developing countries. He also envisioned accreting large aquadynamic OTEC ocean thermal energy conversion plants, both for generating power and for producing hydrogen, ammonia, and magnesium hydroxide.[3] This appeared to result in a building process largely independent of land-based resources.

Waterworld. I talked to Wolf Hibertz by phone before he was driven out of the United States by the concrete industry.

S0's news:

https://www.youtube.com/watch?v=NYoOcaqCzxo

So far I'm 10 minutes in.