This has been stuck in my head all week. :)

I've been spreading Tom Lehrer's 'We Will All Go Together When We Go.'

Anyone who can tell me how you prepare for seven billion hungry predator-omnivores thrown into local autarky or hunter gathering in a world that - in a state of pristine nature it has't seen for ten thousand years - has room for about a hundred million of them, then do tell me. Because honestly, if civilization fails I'd expect the ecology eaten down to dust and everyone dead.