I don't know if it's too late to stop the worst case scenarios of global warming yet or if there's still time, but it doesn't seem to be happening anyway. The world can't deal with something that requires global concentrated efforts.
However, I do think we have time to prepare for the worst case scenarios, and individual countries and states can do that efficiently on their own.
Improve evacuation routines in floodable areas, build greenhouses to deal with cold snaps, ensure there are air conditioned buildings to deal with heatwaves, have distributed local production of electricity, keep strategic food reserves stocked, and so on.
Edit: Not saying that such efforts are the solution by any means, but they will help.
However, I do think we have time to prepare for the worst case scenarios, and individual countries and states can do that efficiently on their own.
Improve evacuation routines in floodable areas, build greenhouses to deal with cold snaps, ensure there are air conditioned buildings to deal with heatwaves, have distributed local production of electricity, keep strategic food reserves stocked, and so on.
Edit: Not saying that such efforts are the solution by any means, but they will help.