Existential Insurance Policy

One compelling argument for space settlement is planetary insurance. Earth faces genuine existential risks: asteroid impacts, supervolcanic eruptions, pandemics, nuclear war, and eventually the Sun's expansion into a red giant. A species confined to one planet stays vulnerable to any sufficiently catastrophic event.

Becoming a multi-planetary species spreads that risk. A self-sustaining Mars colony would mean no single disaster could end human civilization. Carl Sagan argued along these lines, warning that a species tied to a single world is gambling its entire future on that world's safety.