Another risk of global warming

Apparently, if global warming continues, horses will shrink to the size of Robert Reich or something like that.  Because, as everyone knows, large mammals--like rhinos, elephants, hippos, tapirs, zebras, cattle, water buffaloes, and such--cannot survive in a warm climate.  And it's absolutely not like draft horses were developed during the medieval climate optimum or anything like that.  And by no means should we listen to paleontologists who note that dinosaurs are unlikely to have survived ice ages.

One would think that climatologists and hangers-on would check their hypotheses against well known data points, but apparently that's asking a bit much of them.