Next, the researchers looked at how ratios changed over time in souther Greenland. By comparing teeth from the year 1100 with those from 1450, they found that mean annual temperatures dropped by about 1.5C, which would have had significant effects, says Fricke. They reported their findings late last month at a meeting of the Geological Society of America in Seattle. The tooth study corroborates other evidence linking climate to demise of the Norsemen on Greenland. The colony had flourished during the first few centuries of this millennium, but a cooling in the 1300s and an increase in icebergs hampered shipping between Greenland and Iceland, ultimately cutting off contact with Greenland.
Historians believe that the colder temperatures brought food and fuel shortages.
When ships again reached Greenland in the late 1400s, no living colonists remained, says Fricke. Climate may not have worked alone, however. As the region cooled, northern Inuit moved into the Europeans' territory. Anthropologists have wondered whether conflict with the Inuit helped extinguish the Norse colony. Copyright 1994-2001 by Antti Lahelma and Johan Olofsson .