There are two sides of this argument but I don't think anyone disagrees that things are warming up a bit.

Side #1: Warming is due to man's influences on the atmosphere.

Side #2: No, it's not.

Now, if Side #2 was correct, wouldn't they really support their argument by showing exactly WHY the change is happening? Through all this debate, I've only seen Side #2 try to poke holes in Side #1's data and while I've heard other theories as to why we're warming, I've never heard Side #2 explicitly offer up any other cause.