TED Talks on YouTube: What's six miles wide and can end civilization in an instant? An asteroid - and there are lots of them out there. With humor and great visuals, Phil Plait enthralls the TEDxBoulder audience with all the ways asteroids can kill, and what we must do to avoid them.Remember that the theme of this blog is sustainability and collapse with a science fiction slant. What's a better example of a science fiction cause of the collapse of a civilization than an asteroid/comet impact? Better yet, it's something that has shown up twice in Niven's works. Can you say "Lucifer's Hammer" and "Footfall?"
Besides, this is the kind of challenge that, as Phil Plait points out, would be "a blessing in disguise," as it would unite the planet and help develop more advanced space-faring technology. Of course, that presupposes our ability to keep up the level of technology and organization required as a baseline in the first place. With Peak Oil, that might be an issue.