honestly, i don't think it'll be just one "disaster" that'll be ultimately responsible. i'm more inclined to think that a series or a combination of events would lead to our ruin.... i'm thinking natural disasters (as a result of global warming) coupled w/ a supervirus or two and maybe an asteroid thrown in [img]i/expressions/face-icon-small-happy.gif[/img] and i'd give this a timeline of 40 years.