A fundamental problem with the entire issue here is that climate science is not a classic, experimental science. As an emerging science of a complex, chaotic climate system, it is plagued by uncertainty and ambiguity in both observations and theory. Lacking classic, laboratory results, it easily becomes hostage to opinion, groupthink, arguments-from-authority, overstatement of confidence, and even Hollywood movies. When climate scientists are placed in the limelight because this issue can generate compelling disaster scenarios, we simply don’t want to say, “We just don’t know.” -- Distinguished Professor of Atmospheric Science, John R. Christy, University of Alabama, Huntsville, Montreal, June 15. Hat tip: Roger Pielke, Sr.