The discredited, bogus 'hockey stick' temperature reconstruction has motivated hundreds to conduct new research on the paleo-climate, utilizing valid scientific and statistical methods. The vast majority of these new studies confirm the anecdotal historical evidence that the Medieval Period was the warmest extended time span over the last 2,000 years.
Velle et al. recently published a peer-reviewed analysis of sediment cores from the Svalbard archipelago in the Arctic. The analysis revealed the Medieval Warming in a polar Arctic area to be approximately 0.3°C higher than modern temperatures.
"Working with two short gravity cores and two long piston cores of sediments obtained from the deepest part of Lake Skardtjorna, Velle et al. reconstructed histories of chironomid types and concentrations over the past 2000 years, which they translated into mean July air temperatures based on a modern mean July air temperature calibration data set...in the words of the two researchers, a "warming that occurred at 1000 to 830 BP," where BP = 2003, that "may correspond to what is known as the 'Medieval Warm Period'." And based on their graphical representation of that record, we estimate that the peak warmth of the MWP (~ AD 1000-1170) was about 0.3°C greater than the peak warmth of the Current Warm Period. [Gaute Velle, Katrine Kongshavn, H. John B. Birks 2011: The Holocene]