Heat is necessary, AC is not necessary (I realize this is not entirely true, but I think it's fair to say a lot more people would die without heat than without AC).
Living in inhospitable environments is a choice, not a necessity, that is causing environmental degradation. Let’s say an ideal human environment temp is around 60-80 degrees. In 110° weather, you just need to move 30°. In freezing weather you’ve gotta move 48°. That’s 50% more delta.
I think trying to fit the populations of North America, Europe, Russia, China, Japan, Korea, the Stans, Mongolia, the Baltics, New Zealand, Chile, and Argentina, not to mention alpine countries like Nepal, into the ideal human habitability zone would go poorly.
