One of the uncertainties in climate science is figuring out how global climate trends translate into local predictions and reconstructions, and vice versa. A classic example of this is the medieval warm period, the time when Vikings roamed the North Sea and North Atlantic in shallow-draft open boats. They settled Greenland and made periodic visits to North America to get timber, placing some short-lived settlements there.
But there’s a problem. We have the evidence from the adventures of the Norse, but the change to the European climate was so subtle that not many Europeans actually noted it at the time. Apart from exceptional—in both good and bad ways—years, it has been hard to gain a sense of what the typical climate in Europe was like.
To make matters more uncertain, reconstructions of the global climate show little evidence of the medieval warm period—Europe isn’t the globe, after all—and some models show a warm period, while others don’t. Local indicators, such as pollen grains and tree rings, show mixed evidence for the warm period. A recent paper, published in PLoS One, focuses on calibrating climate reconstructions using European data, but one side effect of the work is a further indication that the medieval warm period was really a local event.
This is a really nice presentation of a new paper. It indicates that the Medieval Warm Period may have only been localized to Northern Europe and that Southern Europe was not affected.
Just another indication that the MWP was mostly local in extent, not worldwide.
And the comments are pretty reasonable, with the climate denialists being very nicely discredited by relatively polite rebuttals. Much better than man stires.