The IPCC-favored fabricators of the widely discredited and statistically lame 'Hockey Stick' purposefully claimed that the Medieval Warming was strictly a European phenomenon and its temperatures were below the modern warming - in contrast, yet another study, this one based on research out of China, confirms that the Medieval Warming was unequivocal and unprecedented
(click on map to enlarge - map source)
Read here. Literally, hundreds of paleo-climate studies provide the empirical evidence that the Medieval Warming Period (MWP) was a global phenomenon and highly likely the warmest extended period over the last 1,000 years. In fact, the empirical evidence that the MWP was a robust climate change event sans human CO2 emissions is overwhelming.
The latest study establishing the same comes from a Chinese-led team of paleo-climate scientists:
"...the authors write that "lakes are excellent sensors of environmental change," and that "lake sediments can provide well-resolved records of change on different time scales," while noting that "crater and maar lakes are especially sensitive to climate change because typically they have a small catchment area and limited inflow/outflow."...such lakes "often provide high-resolution records due to limnological processes favorable to the development and preservation of seasonally laminated sediments,"...they add that "diatoms are excellent indicators of environmental conditions and have been widely used to reconstruct Holocene climate variability,"...Focusing on Lake Erlongwan, one of eight maar lakes in the Long Gang Volcanic Field of Jilin Province, NE China...The ten researchers report that "three intervals were identified by their diatom assemblages and correspond within dating uncertainties to the Medieval Warm Period, the Little Ice Age and the 20th century warming trend." During the MWP, they further indicate that "the duration of the summer was longer while the spring and autumn were shorter than the 20th century." And they unequivocally declare that "the period between ca. AD 1150 and 1200 was the warmest interval of the past 1000 years."" [Luo Wang, Patrick Rioual, Virginia N. Panizzo, Houyuan Lu, Zhaoyan Gu, Guoqiang Chu, Deguang Yang, Jingtai Han, Jiaqi Liu, Anson W. Mackay 2012: Quaternary Research]