[FlingWingFlyer]

The North-West Passage – the sea route running along the Arctic coastline of North America, normally perilously clogged with thick ice – is nearly ice-free for the first time since records began.

Obviously they weren't keeping "records" when the Vikings were sailing through it.

[SunkenCiv]

Well said. During the medieval warming, when sealevels really did rise (as opposed to the imaginary rise during the past 150 years or so) and summers freed the waters of the Arctic Ocean, trade and exploration reached the length of Asia.

[CholeraJoe]

Obviously they weren't keeping "records" when the Vikings were sailing through it.

They actually were. They're called "The Sagas of the Icelanders." These detailed records of the settlement of Greenland and the exploration of eastern North America have been conveniently ignored by the global warming crowd. They prefer to blame the warming period of the 11th through 15th centuries on greenhouse gases released by Vikings burning European settlements.