I don't think anyone is seriously arguing that Mars will be more habitable than Earth. The argument is about the possibility of humans on Earth being wiped out due to freak events like a huge asteroid impact or global thermonuclear war. Earth would still be more habitable than Mars, but the probability that human survivors would be equipped with Mars-level survival tools is tiny, and any facility equipped like this would have to be hardened against desperate survivors trying to take it over and bringing it over capacity. Meanwhile if we had a self-sufficient Mars colony they could resettle any Earth that is more habitable than Mars.

Now I'm not saying it's necessarily a smart allocation of resources. But it does follow the popular IT saying "one is none, two is one. If you care about something make sure you have a backup"

▲

fn-mote an hour ago | parent | next [-]

I’m intrigued by lumping “asteroid impact” and “nuclear war” in the same freak events category.

In the US, you’re probably voting for people who will be making the nuclear war decisions…

It won’t be a freak accident, it will be a result of the democracy you participate in.

▲

wolvoleo 2 hours ago | parent | prev [-]

A Mars colony would simply die when it's no longer being supported by earth. Maybe they'll survive a year but not much more.

	▲	wongarsu 2 hours ago \| parent [-]
		Hence "if we had a self-sufficient Mars colony". Any initial mars colony would not be self-sufficient, but even just by economics alone that would change as the colony grows. Even if we get stuck in the "initial colony" stage (which is not the plan of any Mars-colonization proponent) with precautions comparable to the ISS you'd still have a colony capable of surviving a minimum of four years (two launch windows, in case one delivery goes wrong) and the capability to return to Earth.