The environmental cultists.
In cults, when end of the world or rapture predictions fail, some people leave the cult, but many stay and double down on their beliefs; their faith grows stronger
Environmental doomsday-ism shares that feature of a cult. It doesn't matter that Malthus was wrong. It doesn't matter that Paul Ehrlich's prediction of unpreventable mass starvation in the '70s was pure science fiction. It doesn't matter that over a decade ago Charles himself said we had less than a decade to save the planet. No accumulation of failed predictions can shake the devout faith in looming catastrophe.
That doesn't mean the earth isn't warning. That doesn't mean humans aren't a cause of that warming. It means that if you buy into the doomsday-ism, you're joining a cult. You'll tell yourself you're being scientific, but you'll actually be operating on a religious basis.
And if you join that cult and the anti-nuclear cult simultaneously, you'll be as logical as the person who joins a Christian Church and the Church of Satan simultaneously.
Besides, if you told Prince Charles he could save the planet by giving up his cushy valet and trips on the royal charter, maybe wear less expensive suits, he'd probably get really upset.