A hardy Viking colony in western Greenland may have been wiped out by a cold snap coupled with a rise in sea-ice, researchers have found.
The results, published in the journal Boreas, point to an historical example of a population that failed to adapt to Earth's changing climate.
"Our study indicates that at the time the Norse arrived in West Greenland, climate conditions were relatively mild and were favorable to the settlers," said Sofia Ribeiro from the University of Copenhagen. "However, in A.D. 1350, the settlement collapsed, the cause of which has long been debated." [10 Ways Weather Changed History]
Ribeiro and colleagues studied the marine plankton in sediment cores that date back 1,500 years in Disko Bay, Greenland.
"By knowing where the species live today and what are their ecological requirements, we can reconstruct changes that occurred in the past," Ribeiro told LiveScience. It has been shown by other researchers that marine plankton can respond quickly to climate change and amplify even subtle alterations in the environment."
They found a shift toward types of plankton known to persist in sea-ice conditions in layers of sediment that dated to the collapse of this Viking colony in 1350.
"We cannot attribute the end of the Norse civilization to a single factor, but there is enough evidence to suggest that climate change played a major role in determining its collapse," Ribeiro said. "Harsh climate conditions made farming and cattle production increasingly difficult and the extensive sea-ice prevented navigation and trading with Europe."
In another recent study, scientists found that the "little ice age" may have driven the Vikings out of western Greenland. That study, published in the Proceedings of the National Academy of Sciences, was based on ice cores taken from lakes, while the new study is based on sediment cores from the ocean. Ribeiro said the two data types may differ, with the marine perspective being critical to understand a group of people who lived along, and depended on, the sea.
The collapse was likely a gradual one.
"I would suspect their collapse resulted from a gradual lack of resources, with people abandoning several smaller farms to gather at larger ones until a series of very harsh winters eventually made them starve," Ribeiro said. "But we don't know exactly what happened. And this will probably remain a mystery."