We might have destroyed ourselves, but at least it would have been our own fault.
Would it, though? Whose fault exactly? Yours? Mine? No, it would have been the result of several billion human beings making relatively innocuous choices: to have kids, drive a car to work, keep their job, solve the short-term problems first. When you reach the point at which even the most trivial acts are punishable by the death of the species, then obviously, obviously, you're at a critical juncture, a different kind of point of no return.

p. 128 - Spin (2005)