I believe them, yes. I don't see very many reasons not to believe them, and generally the folks I see disbelieving them I suspect of ulterior political motives. Its not convenient to believe it. Its not nice. But I'm not interested in the aesthetic values of my beliefs, I'm interested in the truth of them.
And that is the debate I would rather have then the ones we usually digress into:
Reasons why the man-made theory should be questioned (some of you've seen):
1) We know it has been hotter in human history. That, all by itself, should tell us we should maybe spend some time figuring if that is what's happening.
2) This one is a little different and that is, SO WHAT? As I mentioned before Greenland was named Greenland for a reason. When the Vikings discovered it in about 1200 there was no glacier covering it and potatoes were farmed across much of it (which is starting to happen again). Believe it or not a lot of good can come from this warming trend, specifically longer growing seasons and the ability to grow crops at higher latitudes. I tried to make the case before that most things on the universe have a pattern or cycle to them. Things die and things are born. Species become extinct and are replaced by new ones which eventually die and are replaced by new ones again. Ocean levels of risen and fallen. glaciers have advanced and receeded. So why are we some so certain that dooms day is approaching when what we are seeing now has happened thousands of times before throughout Earth's history?
My 'theory' on that to follow.