Take everything we have now. Remove all of the redundant labor we do purely for profit (pointless middlemen, designed obsolescence, needlessly deep hierarchies to maintain hegemony, throwing away goods if they won't generate enough profit). That's more than enough excess labor to build a substantial bulwark for future disaster and allow people the rest they actually need.

Like, it's so hard to convey how much effort we waste allowing the assholes who want to be on the top of the pile to design society. They just make shitty piles so they can stand on top of them. We can accomplish so much more than this.