I think the way gw proponents might appear to be a sort of cult like, however I think its just a natural reaction to the disturbing excuse for scientific research that the other side puts forth. The opposing side regurgitates complete nonsense in a nonchalant way that clearly makes the proponents look like fanatics when they get fiery and refute this complete nonsense.

The rightwing stance was engineered to look like the reasonable middle ground. Its an easy image to maintain when the other side is pretty much saying the world is ending unelss we change. However the claims against global warming are more akin to intelligent design than real science.