Two new studies, adding to earlier studies that showed parts of Asia and the Americas were cooler during the Medieval Warming Period
one is a global proxies record study, showing the Medieval Warming period was not global
"
The Medieval period is found to display warmth that matches or exceeds that of the past decade
in some regions, but which
falls well below recent levels globally. "
http://www.sciencemag.org/content/326/5957/1256
and another study that shows the setllement of Greenland was not made possible by the MWP, and that it was not the end of the MWP that drove the Vikings out of Greenland
"
A new study questions the popular notion that 10th-century Norse people were able to colonize Greenland because of a period of unusually warm weather. Based upon signs left by old glaciers, researchers say the climate was already cold when the Norse arrived—and that climate thus probably played little role in their mysterious demise some 400 years later. On a larger scale, the study adds to building evidence that the so-called Medieval Warm Period, when Europe enjoyed exceptionally clement weather, did not necessarily extend to other parts of the world."
"Using newly precise methods of analyzing chemical isotopes in the rocks, they showed that these moraines had been deposited during the Viking occupation, and that the glaciers had neared or reached their later maximum Little Ice Age positions between 975 and 1275. The strong implication: it was at least as cold when the Vikings arrived as when they left. “If the Vikings traveled to Greenland when it was cool, it’s a stretch to say deteriorating climate drove them out,” said Young."
http://earth.columbia.edu/articles/view/3266
