That's an interesting point but it's only part of the picture. Rising temperature leads to rising sea levels and islands ceasing to be islands. Loss of habitat numbers will be nowhere near the numbers of deaths from a bad winter but it will be devastating to the displaced people and difficult for the societies that take them in. Even a small increase in sea temperature can kill huge swathes of coral and it's dependent inhabitants.

I belong to the group who think that there are far far far too many humans alive on the planet right now. I have this sneaking suspicion that global warming might be the planet's attempt to redress it's damaging infection of swarming humans. We aren't going to do it ourselves are we?