Churning ocean water is a terrific idea. Especially the added benefit protecting habitats. Thanks for sharing.

--

I also have no clue about the economics of carbon capture. Maybe ask David Roberts? He has always answered my emails. (Note he's currently on vacation.)

Roberts is my current primary source for climate and energy policy news. He definitely talks to all the right people, eg Saul Griffins.

Here's a sample of his articles which may be relevant to your question:

These uses of CO2 could cut emissions — and make trillions of dollars [2019] https://www.vox.com/energy-and-environment/2019/11/13/208395...

A simpler, more useful way to tax carbon [2020] https://www.vox.com/energy-and-environment/2020/8/17/2137073...

Volts podcast: Sen. Tina Smith on the promise of a Clean Electricity Payment Program [2021] https://www.volts.wtf/p/volts-podcast-sen-tina-smith-on-the

Volts podcast: Rebecca Dell on decarbonizing heavy industry [2022] https://www.volts.wtf/p/volts-podcast-rebecca-dell-on-decarb...