Changing an economic system that is bent on uncontrolled and poorly measured economic growth and depends on fossil energy for its main objectives, is much more difficult than changing how nuclear energy is used for military purposes. Some think it may be impossible.
Vaccines [measles] have been proven to be safe, and what happens if you don't take vaccines is children get measles and die. So the anti-vaccine crowd has, you know, kept measles around in a way that - you know, it's a tragedy, because so much is done to make sure these things are safe.