Read here and here. As is well known by now, the IPCC, the MSM and Hollywood wildly (and foolishly) celebrated the "Hockey Stick" caricature of past temperatures when it was first introduced, which portrayed the Medieval Warming and Little Ice Age as non-existent. Subsequent expert analysis by McIntyre and McKitrick found the hockey stick portrayal of past temperatures to be bogus and without scientific merit.
Recently, paleo-climate experts from around the world confirmed that the hockey stick caricature was dead by holding a major Medieval Warming Period (MWP) symposium in Lisbon, Portugal titled "The Medieval Warm Period - Where and when was it warm?". [Archived home web page here.]
Obviously, holding a MWP conference means there is no MWP "consensus" yet, and the IPCC Climategate-style of science is definitely not "settled." Additional confirmation of the MWP existence (pouring salt into Michael Mann's wound) is the symposium's prominent use of a graph from a peer-reviewed study that depicts MWP temperatures matching or exceeding modern warming temperatures. The symposium graph is an ensemble of paleo proxy reconstructions [Jansen et al., 2007]; and, by focusing solely on the ensemble's temperature ranges of the proxies, as depicted in the 'C3' chart below, the Jansen et al. research clearly is more supportive of, and similar to, the McIntyre & McKitrick results instead of the infamous hockey stick results. (click on image to enlarge)
This range of ensemble temperatures is also very similar to the results of multiple other peer-reviewed studies in the paleo-climate science field.
