[medstrom]

That's still not really a hypothesis that connects to TFA as we're still basically proposing "well, the water just flowed down from higher up!" Put it this way, Snowball Earth is not itself a hypothesis for where'd the snow come from to make the snowball.

Also doomsday preppers live on the scale of a human lifetime -- you do agree that geological events don't really factor in?

[lazide]

Original water came from comets, and the protoplantary nebula. Notably, as ‘high up’ as it’s possible to get eh? And frozen.

And doomsday preppers are a personality type visible across all civilizations in some form - due to humanities evolved genetic heritage.

Just like every other type.