The planet is always getting warmer or cooler. It never has stayed the same, and somehow this fact cannot be understood by the average American.
PBS about 2 to 3 months ago had a big two hour deal on why the Vikings left Greenland. When they got there in 1000AD, Greenland was green and lush. When they left in 1400AD, it was an ice bowl. It's still an ice bowl as far as I know. We have quite a bit of warming to do to even get to the level of 1000AD, and I'm quite sure the warming back then wasn't due to man made hydrocarbon emissions, and I believe that earth may have been even warmer in the distant past.
So we have global warming. So what?