I'd turn that around, "We need to start thinking about how human beings are utterly dependent on Earth for the forseeable future and how we're destroying her, because there's no planet B in the time frame global warming is unfolding". Start working on protecting what we have. Don't flatter yourself into thinking there's an alternative.
I'm sure many have read William Shatner's narrative of his trip to real space but if you haven't, you should.
"I saw a cold, dark, black emptiness. It was unlike any blackness you can see or feel on Earth. It was deep, enveloping, all-encompassing. I turned back toward the light of home. I could see the curvature of Earth, the beige of the desert, the white of the clouds and the blue of the sky. It was life. Nurturing, sustaining, life. Mother Earth. Gaia. And I was leaving her." (and continues...)
https://variety.com/2022/tv/news/william-shatner-space-boldl...
Let's first create a self-sustaining vault that can house a million people for indefinite amounts of time on Earth, and then let's revisit sending humans to Mars with all the new technology we developed doing so.
In the meantime, let's actually spend space program resources on actual useful exploration, such as finding out if there is life on Mars or on other liquid-water worlds in the Solar System (such as Europa). Confirming or denying this would be a much much much bigger boon to scientific understanding than getting an ISS-style outpost to last a few years on Mars, and it would also be far cheaper.
The chances of humans surviving on Mars after such an event is extremely less than humans surviving on Earth. We know the Earth has remained hospitable to life after many instances, Mars hasn't been hospitable to complex multi-cellular life in its entire existence, or at least the last billion years or so.
Almost nothing. I agree the Mars colonialization idea is absurd in any foreseeable timeframe. My point is mostly fantasy seems serve to numb people to the damage to Earth that's now going. If someone is worried about the future of the human, they should be working on climate change. Especially if they have enough money and influence to make themselves widely heard, as do many of the people hocking the Mars-boondoggle.
This is such a common viewpoint - that earth will become uninhabitable - but I think you've been watching too many cataclysmic films. In your experience, what makes it so bad?
In my experience, this place is pretty decent. The worst of it is the strong governance systems we have - all these nonsense laws that are really there for someone else's benefit. But, while the strong governance will make/is making our culture unpleasant, there are no worries about the physical matter.
The problem is all the unfounded, unverified stories people believe, despite the evidence of their own senses, if you ask me.
Hard problems on Earth get solved regularly, but they only get solved when there is sufficient payback to justify the costs of finding those solutions.
Without the added justification of "because it's another planet, and that's so cool", I don't think a mars colony makes a lick of sense.
This makes Mars pretty ideal as a home base, if you assume that in the future we are planning to mine and process asteroids for rare minerals and metals.
I love the "might" qualifier.
Let's not forget the heart and circulatory problems too.
Also, there's a very good chance that this type of exploration of Mars will forever contaminate it preventing us from using Mars to explore the origins of biological life, a much more important and achievable goal than space colonization, and one that doesn't shut out the other one in a farther future.
Considering that the "rest of the galaxy", aka the Milky Way is 1,000,000,000,000,000,000 km give or take across, the 250,000,000 km to Mars aren't going to provide much of a head start.
So as already mentioned, good local base for other activities in much more hostile surroundings.
With instructions for their 'gone enabler' engraved in dura-marble?
SPACEDRIVE! :-)
How would you make these islands habitable, including having a good atmosphere, without affecting the rest of Earth's ecosystem in undesirable ways?
That's one major difference. A goal of terraforming mars might actually be easier than terraforming remote islands on earth because:
A. It's an isolated system
B. We can afford to fail
Build a port, and have people delivery stuff by boat.
It's not that hard to do
We could stretch out a long hosepipe..