This is a vid done in 2002 - he describes all the things the very things that we are concerned about today - and solves all the issues as well. Solar Flares, epidemic, et's, black hole, magnetic pole shift, mars population, asteriod hitting earth, loosing the will to survive(depression) collapsing ecosystem etc
worth a watch

http://www.ted.com/talks/stephen_pet...rmageddon.html