[korpiq]

If I understand correctly, currently anthropogenically accumulated extra CO2 takes some hundreds of thousands of years to return to geological circulation, while the faster biological circulation won't withhold it all, and seas are getting saturated (and will acidify beyond supporting current lifeforms in the process). [see eg. Hot Earth Dreams]

Also, if I understood correctly a single article I'll try to dig up a link to later, the kickback effect of stopping a temporary cooling measure and returning to the warming trend caused by the CO2 still in air will have stronger harmful effects. If these hold, it might prove tricky to keep up a moderate, safe cooling effect long enough, even if some technical measure to cause volcanic winter was found. [https://www.nature.com/articles/s41559-017-0431-0?utm_source... via https://www.rollingstone.com/politics/politics-features/devi...]

I would hope this or some other measure would prove successful. but I'm not yet able to put all my faith on any of them.