What country is going to take the hit and start the high altitude sulfur spraying? If we even could get the forcing back to what it already was in the recent past that would be a great help.
As long as is needed to transition away from burning fossil fuels. You can always put more in high altitude. If half the comments here are right and climate change is truly an apocalyptic threat, then acid rain and global dimming would be worthwhile tradeoffs.
If climate change isn't extremely bad, then maybe it's not worth it. But at some point, if it becomes existential, then all options are on the table.
> Masking the problem will only make it come back harder when measures don't scale up anymore.
If (e.g.) China stops the US can start, or if a small country can't scale up enough more countries can join in. The whole "termination shock" thing is highly overrated, it's solvable with next to no communication at all. Decision rule: if not enough is being sprayed according to your models, make up the difference yourself.
