Why is global warming a bad thing?

[Tommy]

First, I respectfully request that those of you who see most threads as an opportunity to bash your least favorite political party or continue unwinnable disputes with adversaries from long ago threads, please give this one a pass.

In a discussion on another forum, a member from Canada mentioned that he was expecting temperatures in his town to reach minus 40C in a day or so. That got me thinking. There is pretty good evidence that the surface of the Earth is warmer today than it was during the last ice age about 20,000 years ago. So, in my opinion it's fair to say that we've been in a warming trend for some time. Without commenting on what caused the warming trend, I ask this question. Is global warming always a bad thing? For example, I can see where it would be bad for residents of a low lying island nation that is being threatened by rising oceans. But, if I lived where the winter temps routinely reached -40C, I might see global warming as a good thing. So my question boils down to this. Has anyone done an objective study of the negatives AND positives of global warming to determine who the losers and winners will be? Change is something we all have to face in our lives, and it seems reasonable to me that some will benefit from changing global temperatures.