[ffhhttt]

> Han civilization

Sorry. I’m not sure how did I manage to write that, it was supposed to be “civilizations have [thrived]”.

> Earth has never been as inhospitable to human life as it's expected to be since any known civilization started,

That debatable and very hard to quantify. Also it really depends on the region, e.g. Europe was probably quite worse than now during the “little ice age” or the 600s (coincidentally the Arabian peninsula seems to have thrived during that period due to higher humidity).

Climate change was the reason many ancient civilizations collapsed, it seems to have been a pretty regular occurrence and we were only be to break out of that circle in the late middle ages/1500s.