If we can't avoid overpopulating a planet, how and why should we think will we avoid overpopulating Mars or Mini Ringworld? Well if plan B in space is for only

If we can't avoid overpopulating a planet, how and why should we think will we avoid overpopulating Mars or Mini Ringworld? Well if plan B in space is for only some, it's not saving humanity but is a "fuck you" to most of them. I think some pretty core human problems will show pretty damn quickly after that: Once the remaining 6.9bn realise they're not invited to the party, that there is a definite plan for all the wealthy and politician types to piss off to Mars or some space station, the rest might very reasonably decide that's a tad unfair. Especially if their own future is some apocalyptic die off, perversely made worse by all those emissions from the thousands of rocket launches. They might sensibly think that instead of quietly waiting for the 4 horsemen to show up with their exit, better to go out by trashing all the supply rockets and bases of project space, and reach for petrol, pitchfork or assault rifle. Maybe one more emission laden launch to blow those entitled assholes out of orbit... We haven't yet shown viability in any of the sealed biome experiments. Not once. The old Russian experiments back during their lunar programme got closest. Hence me thinking much cheaper and simpler just to address the damn problem properly. :)