You need money/people on board, but not on the order of 80% of the people of the world; you need the leadership of singular countries to decide to do something.

You need money/people on board, but not on the order of 80% of the people of the world; you need the leadership of singular countries to decide to do something. Consider how easy it was for individual countries to pour a ton of resources into developing atomic bombs, compared to how difficult it has been for countries to come together and agree to get rid of nuclear weapons. It's easy for a country to do what's in its own self-interest. It's difficult for multiple countries to come together and do things which are in everyone's common interest but which is against each individual country's interest.