Here is a good description of what is wrong with AGW science.

http://pajamasmedia.com/blog/anthropogenic-global-warming-the-greatest-fraud-in-history/

What has most impressed me about the AGW hypothesis is how the supporters act in such unscientific ways. They present data that they know are flawed. They distort weather events, claiming that all unusual weather events are caused by increased Greenhouse Gas levels. They admit that they exaggerate consequences to gain attention from the media, who are only interested in reporting disasters. They issue ad hominem attacks on those who disagree with them rather than addressing arguments. They rely on spokesmen like Al Gore, Laurie David and Leonardo De Caprio, people who have no scientific knowledge, and who couldn't engage in a meaningful dialog about the subject. And they refuse to have any sort of honest debate about the subject.