AbstractThis paper first reviews previous work undertaken to assess the level of scientific consensus concerning climate change, concluding that studies of scientific consensus concerning climate change have tended to measure different things. Three dimensions of consensus are determined: manifestation, attribution and legitimation. Consensus concerning these dimensions are explored in detail using a time series of data from surveys of climate scientists. In most cases, little difference is discerned between those who have participated in the IPCC process and those who have not. Consensus, however, in both groups does not amount to unanimity. Results also suggest rather than a single group proclaiming the IPCC does not represent consensus, there are now two groups, one claiming the IPCC makes overestimations (a group previously labeled skeptics, deniers, etc.) and a relatively new formation of a group (many of whom have participated in the IPCC process) proclaiming that IPCC tends to underestimate some climate related phenomena.