Yes, there may be global warming–but what if it’s just a cyclical return to the way the earth’s climate was 1,000 some 600 years ago, when northern Europe happened to be a lot warmer than it is now?

That’s what seems to be the case in this fascinating report from Der Spiegel (thanks, Arts & Letters Daily), for it seems that Greenland, an icy wasteland for hundreds of years, is poised to revert to the inviting home of pasturelands and forests that it was when the Vikings discovered it back in the 10th century::

“When he saw the island for the first time, explorer Eric the Red called it “Greenland,” partly to entice settlers to board 25 ships and emigrate there. His advertising slogan was certainly justified. In excavations on Greenland, archaeologists have found ample evidence of rustic banquets where beef and mutton were consumed. Eric the Red owned stables that housed up to 100 cattle each.

“Large sections of the northern hemisphere enjoyed a period of unusually mild weather at the time, possibly caused by changes in Atlantic Ocean currents. But the settlers’ meteorological good fortune was short-lived. Climate models based on data from ice cores show that temperatures plunged quite abruptly in the 14th century, triggering a minor ice age and probably driving the Vikings from Greenland. The last known records, handed down over generations, document a wedding in the church of Hvalsøy Sept. 16, 1408. Today, all that remains of the Vikings’ rural life on Greenland are the foundations of their houses.

“But now the mild temperatures of the early Middle Ages have not only returned, but are even warmer than in the days of Eric the Red. ‘Just a few years ago there was ice where we are now standing,’ says Stefan Magnusson, as he sits on his horse and looks down at a stream gushing from the glacier in front of him.

“The first plants are already sprouting from the muddy residues of the moraine. ‘What we are experiencing here is a genesis,’ says Magnusson, his voice filled with emotion.”

As medieval historians will tell you, the first round of “global warming” in the West triggered a twelfth-century renaissance of learning, trade, industry, and technology that made the West for the first time the powerhouse of the world. Before that, all wealth was material wealth–gold, gems, spices, silk–and all of it was in the East. The West was a backwater. The climate change that that gave hundreds of years of mild weather to now-chilly northern Europe triggered technological dominance that has never stopped.

So, can global warming be all bad? It certainly wasn’t so bad the first time around.