[Wonder Warthog]

"I ask all enviros the obvious question. Since there have been next to no witnesses in those areas until recently, how do we know this isn’t a common occurrence?"

Ditto that. During the Medieval Warm Period, the earth was warmer than it is today. What was the "arctic sea ice" doing then???

[The_Reader_David]

I wonder if there is any evidence from Viking records concerning sea ice.

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.