So they have the carbon as bicarbonate, and they are reforming carbon dioxide?

I'm no chemist, but ... is there something solid that it could be converted to instead? Like baking soda, rather than a difficult to store gas?

Maybe something like this?

https://www.scientificamerican.com/article/desalination-brea...

Wow, I didn't know salinity doubled in the Arabian sea in only 10 years.