We've lived with cooling already. For most of our current Quaternary Ice Age (that we evolved in), it was cooler most of the time. Ending it, and we're in much

We've lived with cooling already. For most of our current Quaternary Ice Age (that we evolved in), it was cooler most of the time. Ending it, and we're in much less charted waters. We might revert the Earth to its normal hot climate, but this is one where mammals do not thrive, potentially do not even survive, except at the poles.