Ditto that. During the Medieval Warm Period, the earth was warmer than it is today. What was the "arctic sea ice" doing then???
Let's remember they called Greenland "Greenland", and apparently had farms in the parts they settled. And, while the Arctic sea ice is melting a lot more the past few years than it has lately (or perhaps since the 'Age of Exploration'), not only is the Antarctic continental ice sheet at record thickness, so is the Greenland ice sheet.