I'm afraid that this is more of the kettle calling the pot black. Which is less credible? IMO, it's those who make such sweeping conclusions about AGW without enough data and who rely on manipulated models to promote a cause instead of conduct research according to the Scientific Method. If the AGW crowd were real scientists, they would be trying to disprove their theories instead of overlooking all the other factors that could be contributing to the current warm climate.
There are plenty. This video explains, among other things, why they're overwhelmed: http://www.freerepublic.com/focus/f-news/1803521/posts