Why is global warming a bad thing?

[Excaliber]

Let's spread it out, I like the Polar Bears, I'd pay a bit more in taxes to keep them around, if everybody did the same...

Snail darters? Uh, I don't know anything about them. Maybe even the smallest creature has something to add to the planet, maybe not. Deciding which species will survive, which will die is actually a pretty serious decision. I'll leave it to the experts and hope for the best in that regard.

[RAZOR]

Look its much easier to look at history to answer this question,then to say that what might be if this or that happens. We don't know how the next 10 to 20 years will bring in warming or cooling.
We do know that when the earth had a warmer climate 800 hundred years ago, that is warmer then it is now, there were many benefits to Europe, and Greenland. In England they were able to grow vineyards and have bountiful harvests of grain that included the rest of Europe. Then came a cooling of the climate, there was famine, and pestilence which resulted in the Black Plague. Those Vikings that had settled in Greenland also suffered famine, because they were not able to raise crops, and consequently had to leave after many generations had lived there.
So based on history I believe a warming effect that like happened in the middle ages might have some definite benefits. They were more prosperous, and healthy during that time.