Space exploration necessitates a technological industrial civilization. So they/we would somehow have to figure out how to first do #2 (so as to not die), while still maintaining the industrial capacity to spread out into space. That sounds like an even more improbable subset of the already improbable scenario #2.
Climate change is just one of six planetary boundaries that we’ve crossed, out of a total of nine. The choice of rocket fuel is largely inconsequential compared to the effects of maintaining the industrial capacity necessary for such endeavours.
Space exploration necessitates a technological industrial civilization. So they/we would somehow have to figure out how to first do #2 (so as to not die), while still maintaining the industrial capacity to spread out into space. That sounds like an even more improbable subset of the already improbable scenario #2.
It’s obvious that stars provide obscene, unimaginable amounts of energy. It’s also clear that this energy can be captured and stored.
We, currently, can’t exit our orbit without using oil, but that does not mean it’s theoretically impossible.
Climate change is just one of six planetary boundaries that we’ve crossed, out of a total of nine. The choice of rocket fuel is largely inconsequential compared to the effects of maintaining the industrial capacity necessary for such endeavours.
Don’t most rockets use hydrogen oxygen reaction? Separating hydrogen from oxygen requires only electricity, which we can produce renewably.