perspective on mass extinction
A Mass Extinction Event is a sad thing, but life has a way of bouncing back, new and strange. We're unlikely to kill off life on Earth. Even if we do, there are 100 billion stars in our Galaxy and 10 billion galaxies in the observable Universe, for a total of roughly 1021 stars. So, if we screw up, it's no big deal... except for us!
-- John Baez, "Zooming Out in Time" Long Now Seminar, October 13, 2006
Stewart Brand wrote a summary of the talk, with links to slides