"The only place that does not fit the observed warming pattern is Greenland, which did not begin to emerge from the last Ice Age until roughly 15,000 years ago. The authors believe that this anomaly may be because the North Atlantic experienced continued, hyper-cold winters during the intervening 2,500 years that prevented the region from warming on average."

What if Greenland was at the north pole 15,000 years ago? The cold would have kept the Greanland area frozen to fit the model. And it's opposite pole would have been in the southern hemisphere ocean, which would have melted w/o a trace. This suggest a polar shift has occured in the past?