Well, there were a few times in the last few hundred years of warmer global weather. And those coincided with good economic times for humans. Perhaps global warming would be detrimental to other species more than humans, as humans adapt well, particularly to more pleasant environments.

I don't think that's true. The two big changes in the past thousand or so years were the Medeival Warm Period and the Little Ice Age. Both were more regional than global, and the Little Ice Age coincided with the Industrial Revolution, which of course started extremely good economic times.