[antognini]

> However, we know from geology and paleontology what's happened in previous major warming periods: mass extinction, and a huge loss of biomass, with most of the survivors clustered around the poles.

I thought that warming events were generally associated with speciation events, at least on land. (Marine life is a different story.) The last event, the Paleocene-Eocene thermal maximum, coincided with a major speciation event for mammals.