re: #55 Fred Galt

Let’s get really depressing. Let’s say, worst case scenario; the rapid climate change triggers a Permian-Triassic extinction and wipes out all higher life forms.

Would there be enough time for another intelligent species to evolve or will the sun fry the planet to a crisp by then?

Even the worst-worst-worst case scenarios don’t posit an end to all human life on Earth. If 95% of us die that would certainly be the end of civilization as we know it, but even then it wouldn’t take more than 8 or 10 generations to rebuild to something not entirely unpleasant.