evidence: A new paper has revisited the question of whether there’s a consensus among climate scientists about the reality of anthropogenic (human-caused) global warming (AGW). The study, by John Cook, of the University of Queensland’s Global Change Institute in Australia and the Skeptical Science site, and several co-authors, confirms that climate scientists have not only accepted the existence of global warming, but also its human causation, as a matter of fact for the last two decades. [...] This latest publication by Cook and co. has resulted in a kerfuffle among some of the climate-change-friendly bloggers that I think is worth mentioning. One blogger I follow closely, Dan Kahan of the Cultural Cognition Project at Yale University, has expressed unhappiness about it on the grounds that re-determining or re-emphasizing the existence of consensus doesn’t advance climate science communication. Kahan and I, like most social scientists, are opponents of what’s known as the "deficit model" of science communication, which posits that people are empty vessels into which one can simply pour facts. Rather, I believe that people accept, or reject, new information mostly on the basis of their pre-existing knowledge and beliefs. So merely telling the average citizen that 97 percent of climate scientists believe that humans are causing climate change isn’t likely to change many minds about the issue. [...] John Cook et al., "Quantifying the consensus on anthropogenic global warming in the scientific literature," Environ. Res. Lett. 8, 024024 (2013), doi:10.1088/1748-9326/8/2/024024.