And that the good ones are as apt to migrate quickly to new ranges as the bad, and that "good" or "bad" designation will follow the animal wherever it goes, and so forth. All of these are uninformed assumptions, made in ignorance and completely wrong. Nobody is starting from that assumption. Nobody is even assuming that the changes will be toward "more animals". People will vacation on the polar ice more readily than they will vacation in the slums of Mumbai in the middle of the summer, I'm betting. One of the reasons they can vacation under palms is that there aren't a whole lot of people already living under those palms. (There's a shortage of fresh water, often. Also food. And the summer heat is brutal, often. And so forth.) The question is whether, when they come home from their vacation, they regard the new prevalence of horrible diseases in their home towns (where there are still no palms, and there will be no palms unless their existing trees die) as a good thing or a bad thing. I'm guessing bad. And whether they regard the new heat at night when they are trying to sleep - without those nice ocean breezes and waving palms - as good or bad. And so forth. People don't take vacations to the Seven Ovens of China in the middle of summer. And if the oven weather comes to them, while getting even worse where it is now, things will get ugly in a hurry. Heat already kills more people than cold, now.