That's one great thing about sunshades- they can be implemented by just convincing a spacefaring billionaire or two instead of having to change policy / steer nation-states.
Unfortunately, you still need to convince the billionaire that the project will make him into a 10-billionaire, otherwise he’ll just keep it in the bank, or bathe in it or whatever rich people do with all the vast piles of money they are sitting on.
Perhaps there's the chance that they're interested in their legacy being saving the human race. There will probably be statues of them, schools named after them, and who knows what else if the plan succeeded.
