I personally feel like the only way out now is some sort of active geoengineering solution. You're not going to convince everyone across the world to cut their emissions of greenhouse gases, and I suspect that even if you manage to do that, we have released too many gases into the atmosphere already.
This for whatever reason is even more unpopular than population control and nuclear power.
I completely agree though. Emission cuts are just not going to happen fast enough under any even slightly politically plausible scenario. It's a fantasy.
It also tends to actually be more expensive then any other solution (other then doing nothing in the short term). The huge sources of SO4 or whatever you plan to use have to actually be produced from somewhere.
We could turn ourselves around, and then literally nuke those who chose not to. It is technically possible -- we have all the tech, power, and people to do it.
Meanwhile: The political focus is on building walls.
