This is actually a terrible idea, because to keep the air breathable you'd have to raise the oxygen fraction, making fire risk much worse. (Inert gases in air suppress fires by carrying away heat, making it harder to sustain a flame.)

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WalterBright 10 hours ago | parent [-]

People live on mountains just fine.

	▲	AlotOfReading 5 hours ago \| parent [-]
		This exact same problem exists on mountains, which is why there are no permanent settlements above 5,100m. The Apollo pressure mentioned above (1/3rd atm) is roughly equivalent to an elevation of 8,500m, well into the "death zone" for a normal atmospheric mix.