we havent changed 'enormously' in the last 2 thousand years, whats so special about the upcoming one thousand?
Yeah we have, radically in some ways, other ways, perhaps not so much, but I doubt you could take people from 2K years ago and have them function in the modern world, nor could you go back and live that life either with any ease.
When people speak of saving the world, they are really saying "saving the human race" the world goes on. And, if history is any guide its not the "smart" ones who survive those events, its the biggest, strongest, best armed and most organized packs, or tribes that do well. The "intellectually superior" will go long before the Hell's Angels do.