Let's pretend that the US didn't recently pull out of the Paris Climate Agreement. Let's also pretend that all the other countries that scolded it for withdrawing also met their Paris pledges on deadline. Heck, let's pretend that that everyone in the whole world did their very best to cut emissions, starting today. Even if all that make-believing came true, the world would still get very hot.
Geoengineering, what could go wrong?
That said, neither she nor Niemeier advocates employing either technology at the moment. Too many unknowns. Suddenly cooling the planet could cause freaky weather all over the world. It could interrupt India's annual monsoon. The globe's wind patterns could change completely. Plus, you'd have to keep flying planes into the stratosphere for a very long time—remember, all that carbon dioxide is still in the atmosphere, releasing trapped heat. Also, poisoning the ocean.
Read article here...
https://www.wired.com/story/lets-talk-geoengineering/
I think the article is interesting but it is humorous that that talk about when, if, and how to deploy geoengineering technologies as if they are not already using them.