There's a ton of literature on the ideas and the caveats. Perhaps https://web.whoi.edu/ocb-fert/scientific-literature/ will be a useful, although somewhat dated and limited, introduction to the fertilization idea.
Another idea is to alter the pH of the ocean.
These topics are not at all simple. They are active areas of research in labs across the world. They have been since the 1980s, and I would not say the solutions are around the corner.
A somewhat new feature in all of this is that venture capitalists are getting into the picture, hoping to make money from developing solutions to the climate-warming problem. Their influence makes it a bit hard to judge what methods might work best. And experts in the field have a right to be ambivalent about receiving research funding from groups that benefit from hiding successful results until patents can be established.
Another idea is to alter the pH of the ocean.
These topics are not at all simple. They are active areas of research in labs across the world. They have been since the 1980s, and I would not say the solutions are around the corner.
A somewhat new feature in all of this is that venture capitalists are getting into the picture, hoping to make money from developing solutions to the climate-warming problem. Their influence makes it a bit hard to judge what methods might work best. And experts in the field have a right to be ambivalent about receiving research funding from groups that benefit from hiding successful results until patents can be established.