For the first time temperatures over the last 5,600 years have been reassembled from the inhabited area of Greenland. (Other estimates were from ice-cores that are far inland.)
William D’Andrea, the paper’s first author says: “.. we can say there is a definite cooling trend in the region right before the Norse disappear.”
Greenland’s early Viking settlers were subjected to rapidly changing climate. Temperatures plunged several degrees in a span of decades, according to research from Brown University.
What climate scientists have been able to ascertain is that an extended cold snap, called the Little Ice Age, gripped Greenland beginning in the 1400s. This has been cited as a major cause of the Norse’s disappearance. Now researchers led by Brown University show the climate turned colder in an earlier span of several decades, setting in motion the end of the Greenland Norse. Their findings appear in Proceedings of the National Academy of Sciences.
D’Andrea points out that climate is not the only factor in the demise of the Norse Western Settlement. The Vikings’ sedentary lifestyle, reliance on agriculture and livestock for food, dependence on trade with Scandinavia and combative relations with the neighboring Inuit, are believed to be contributing factors.
Still, it appears that climate played a significant role. The Vikings arrived in Greenland in the 980s, establishing a string of small communities along Greenland’s west coast. (Another grouping of communities, called the “Eastern Settlement” also was located on the west coast but farther south on the island.) The arrival coincided with a time of relatively mild weather, similar to that in Greenland today. However, beginning around 1100, the climate began an 80-year period in which temperatures dropped 4 degrees Celsius (7 degrees Fahrenheit), the Brown scientists concluded from the lake readings. While that may not be considered precipitous, especially in the summer, the change could have ushered in a number of hazards, including shorter crop-growing seasons, less available food for livestock and more sea ice that may have blocked trade.
From Brown University
See also my other posts on the Medieval Warm Period, and Little Ice Age. If anyone tries to claim the Warmth in Greenland 1000 years ago was a local phenomenon, look at this assembly of hundreds of studies from every continent (bar Australia) showing that it was warmer all over the globe, and that the hockey stick is a minor flawed set of studies in disagreement with most of the data.
Thanks to John McLean for the image at the top.