I don't know what you're talking about re: hormones, but in general I think the best idea is to do both things, though I don't think the risk to humanity comes from damaging Earth, so much as damaging each other. Over the past 2 years I think we came far closer to nuclear apocalypse than most people realize. Certainly far closer than anytime besides the Cold War. And over the 2-3 years before that a global disease spread and seems to have infected basically 100% of humanity. And this disease was most likely created by humanity, and released by accident. We're only fortunate that it was relatively harmless compared to what it could have been.
Now that's happened all over just the past 4 years. What do you think of our chances 20, 50, 100, and more years in the future hold hold? It's pretty easy to see plenty of timelines where we do eventually manage to kill ourselves, and so expanding beyond Earth is critical. Of course that doesn't mean we should neglect Earth in any way, shape or fashion. But with 8 billion people on this planet, we can manage to do more than one thing at a time to quite a high degree of competence.
In any case, point is: We need to stop being a threat to ourselves, and hoping that another planet, for which we're not evolved to survive on, is a better choice feels like the wrong path. Humans are amazing at surviving... on earth. Because we evolved to survive here.
Having a "plan B" is not a bad choice, because a lot can happen that we cannot prevent. However we can't resettle everyone. Most will die. Plan B is to continue the species, but not necessarily to actually save us.
Interesting article. Thanks. And yeah I strongly agree that there are a lot of questions about how childbirth outside of Earth will work. Another simple issue is would people born on Mars even be able to ever return to Earth (assuming they're otherwise healthy)? How the body will evolve and adapt when all you've known is 1/3rd g is an interesting and open question that we're only going to be able to completely answer by doing.
I also completely agree with everything re: Earth. But one thing I'd add there is that I think humanity actually starting to settle Mars will dramatically shift the mindset of both people and countries. Imagine China was engaging in mass transit to populate and build up New Beijing. It's not like the US would simply stand by. And today I think many people are not so interested in these ideas, because they think it's simply impossible. I'm thinking more like New World parallels rather than Space Race.
Now that's happened all over just the past 4 years. What do you think of our chances 20, 50, 100, and more years in the future hold hold? It's pretty easy to see plenty of timelines where we do eventually manage to kill ourselves, and so expanding beyond Earth is critical. Of course that doesn't mean we should neglect Earth in any way, shape or fashion. But with 8 billion people on this planet, we can manage to do more than one thing at a time to quite a high degree of competence.