Read here. The IPCC and its Climategate scientists became completely possessed in proving the Medieval Warming Period did not exist. This caused them to rely on non-professional, highly questionable statistical methods and obvious fraudulent tree-ring data manipulation in order to "prove" that the Medieval Warming really did not exist, despite the preponderance of actual historical writings about that actual warming era. In addition to the written recorded history of the Medieval Warming, scientists have documented hundreds of sites, globally, confirming the warming during the Medieval Period. One such site was in northern Russia, where it has been established that the treeline existed at a much higher elevation during Medieval times, due to the unprecedented warmth. (click on image to enlarge)
