Read here. The IPCC Climategate scientists have worked mightily at eradicating the Medieval Warming Period and Little Ice Age but this fabricated interpretation of historical temperatures is continually challenged by an increasing accumulation of actual scientific evidence. The latest peer-research from China is a study of ancient tree-trunks that provide 2,300+ years of tree-ring evidence, which clearly indicates the Medieval Warming was much warmer than modern temperatures. (click on image to enlarge)
"Zhang et al. conclude that their proxy climate data "reveal that the North Atlantic MWP and the LIA were accompanied by climate changes on the northeastern Qinghai-Tibetan Plateau," while their comparison with Esper et al.'s data indicates that their data are also well correlated with long tree-ring chronologies from much of the Northern Hemisphere. The research team thus provides important evidence for the broad geographical reach of both the MWP and the LIA."