To coordinate that many people, you would need either:

• a political party that would coordinate global actions via some sort of hierarchy
• a disaster of some kind that affected enough of the population that the entire world could be convinced to act all at once, or at least in quick succession, but still didn’t take out all of our communication structures so decentralized communication would still be possible.

We saw how Covid worked out so I think the likelihood of everyone not only acting at once, but also in unison, because of a disaster is quite small without a party to coordinate. There need to be constraints on behavior with levers of power to pull and enforce those constraints in order to get literally billions of people to do the same thing at the same time. I don’t see a way around it.