Scientists have long known that climate change was happening in West Greenland over the past 5,000 years, but until now they have not been able to quantify the specific conditions of that change. New research has allowed scientists to predict that abrupt temperature changes by as much as 4 or 5 degrees Celsius will have had profound implications for the peoples that occupied western Greenland during that time.
Due to ice cores recovered from the large ice sheets that cover a large majority of Greenland, scientists have had a good understanding of hemispheric- and millennial-scale climate variability in the North Atlantic and Europe over the past several millennia.
But this latest research, published in the May 30-June 3 online edition of the Proceedings of the National Academy of Sciences, has allowed scientists to understand the climate changes in western Greenland, and what it may have done to the inhabitants.
Studying carbon-dated sediment cores taken from the beds of two saline lakes near Kangerlussuaq, West Greenland, an area north of the two major medieval Viking (Norse) settlements, scientists measured the qualities of haptophytes (salt-loving microscopic plants) using a new technique that allowed them to identify the temperature the haptophytes were living in.
What they found was that the organisms revealed a handful of temperature shifts that took place one after the other over nearly 5,000 years, and that roughly coincided with changes in the occupation of the area by human inhabitants, including the Saqqaq people (4,500 to 2,800 years ago), the Dorset (2,800-2,000 years ago), the Norse (1,000-550 years ago) and the Inuit (800 years ago to present).
“The research is important because the study has basically described and quantified the temperature variation during the last 5,000 years in this area of West Greenland which has had a fairly rich cultural history over much of that time period,” said Fritz, George Holmes university professor of earth and atmospheric sciences.
“Some of the changes are quite rapid and fairly large. There’s a temperature drop of about 4 degrees Celsius starting about 800 years ago when the Norse were still there, but the reconstruction suggests that within 80 years, temperature dropped 4 degrees during summer months and stayed quite low, so it’s quite a large fluctuation. And there are other periods when temperature change was quite rapid and substantial, in the order of 4 to 5 degrees Celsius.”
Source: University of Nebraska-Lincoln