How Greenland's cold beat the Vikings

We'd be the last to demean the Vikings as wusses but the legendary Norsemen ultimately proved no tougher than the current crop of humans when it came to battling the elements.

It's been generally believed that falling temperatures disrupted the lives of Norse settlers and forced their decision to leave Greenland. Now a new study offers conclusive data to help fill in our understanding of the world they faced - one that was by any measure, increasingly nasty, brutish and short

Examining core measurements taken from a couple of lakes near Norse settlements in Greenland, a team of researchers led by Brown University came up with what's believed to be the first factual reconstruction of temperatures from that time. And the evidence they found points to a steady drop in the thermometer starting around the year 1100.

Over the next eight decades, Greenland's temperature fell by 7 degrees Fahrenheit, a decline that likely had calamitous effects. Not only would a shorter crop-growing season result in less food for the settlers, it would also reduce the supply of food available to their livestock, turning the Vikings' daily lives into even more of a relentless fight for survival.

"You can imagine how that particular lifestyle may not be able to make it," said William D'Andrea, who co-authored a paper on the topic. He noted that the Vikings found themselves faced by the prospect of long, cold dark winters and shorter, colder summers which cut into their ability to make as much hay.

Besides farming, the Vikings also were hunters, relying on caribou, as well as on marine mammals - "and those are two things that could have potentially changed," D'Andrea said.

Another possible reason behind the Vikings' decision to abandon their settlements: Increased ice that likely impeded trade with Scandinavia.

"They had a pretty healthy trade with Scandinavia and anything which interrupted that would have been detrimental," he noted.

Despite its remote location, however, Greenland has been a magnet for human occupation as far back as 4,500 B.C. However, settlers have also faced a harsh existence and the region was unpopulated until the arrival of the Norse toward the end of the 10th century. The ancestors of the latter-day Inuit arrived in Greenland two to three centuries later. In fact, conflict with Arctic peoples also factored into their decision. By the early decades of the 15th century, the Vikings had had enough and pointed their ships toward Scandinavia.

The paper was published in the Proceedings of the National Academy of Sciences.