I recently ran into a NOAA [1] scientist and talked to him briefly on the subject. He claimed that was there was effectively no one in the field that had any doubt about anthropogenic climate change, although there were many disputes about details. The few who do argue against it (he knew them by name) are very respected and intelligent, but have contrarian personalities, and tend to dispute specific models and argue in favor of uncertainty, rather than arguing that human behavior is definitively unrelated.
Scientific communities are far from immune to taboos and group-think, and I think every idea deserves scrutiny and (true) skepticism, no matter how "settled". But while the science continues to iterate and refine, policy decisions should be based on weight of evidence, which is vastly in favor of human-caused climate change.
The simple fact of the matter is that something would have to be badly wrong with the laws of thermodynamics and the theory of chemical bonds in order for our understanding of human climate change to be sufficiently defective that the delusionals point of view was somehow more correct than the consensus view.
Our understanding of the laws of thermodynamics and the theory of chemical bonds are basically what enable civilisation as we know it.
Scientific communities are far from immune to taboos and group-think, and I think every idea deserves scrutiny and (true) skepticism, no matter how "settled". But while the science continues to iterate and refine, policy decisions should be based on weight of evidence, which is vastly in favor of human-caused climate change.
[1] http://en.wikipedia.org/wiki/National_Oceanic_and_Atmospheri...