Well, at least Old Guy's continuing list of "Oh, yeahs?" is a good way to have all the usual complacent and stereotyped objections to the warnings in one place, so that some of us can answer them, leaving food for thought for those who wander in.

Ahem...the asteroid deflection ideas are WAY in the theory stage so far,(I hope they DO come up with a good one!) but there are LOTS of ways to reduce Ozone depletion and greenhouse gas emissions, etc. already.