Vikings Were Affected by Climate Change: Study

William D'Andrea (R) and Yongsong Huang of Brown University took cores from two lakes in Greenland to reconstruct 5,600 years of climate history near the Norse Western Settlement. (William D'Andrea/Brown University)

A long cold snap during the 12th century may have contributed to the Vikings’ disappearance from Greenland, according to research published in Proceedings of the National Academy of Sciences.

The Norse colonized Greenland in the 980s during a period of fairly mild weather, and withdrew in the 14th and early 15th centuries after a period of freezing weather, known as the Little Ice Age. Other factors are believed to have been involved, such as a reliance on trade with Scandinavia, and fighting with the Inuit.

However, climate scientists have taken ice cores from two lakes near the Norse “Western Settlement” that cover 5,600 years of history, and found that an earlier cooling period may also have had an effect.

“This is the first quantitative temperature record from the area they were living in,” said first author William D’Andrea at the University of Massachusetts–Amherst in a press release. “So we can say there is a definite cooling trend in the region right before the Norse disappear.”

“The record shows how quickly temperature changed in the region and by how much,” said co-author Yongsong Huang at Brown University in the release. “It is interesting to consider how rapid climate change may have impacted past societies, particularly in light of the rapid changes taking place today.”

An 80-year cold snap to around 4 degrees Celsius (7 degrees Fahrenheit) began around 1100 which the scientists believe would have affected livestock food availability and possibly blocked sea trade.

“You have an interval when the summers are long and balmy and you build up the size of your farm, and then suddenly year after year, you go into this cooling trend, and the summers are getting shorter and colder and you can’t make as much hay,” D’Andrea said. “You can imagine how that particular lifestyle may not be able to make it.”

The team also looked at Stone Age settlements in the area by the Saqqaq and Dorset peoples. The Saqqaq arrived in Greenland around 2500 B.C. and left about the time the Dorset people arrived, who could hunt from the sea ice during colder periods.

At around 850 B.C., there was a strong cooling period. “There is a major climate shift at this time,” D’Andrea said. “It seems that it’s not as much the speed of the cooling as the amplitude of the cooling. It gets much colder.”

Yet despite being able to cope with cold weather, the Dorset people began to disappear around 50 B.C. in western Greenland. “It is possible that it got so cold they left, but there has to be more to it than that,” D’Andrea said.