The surprising reason the Vikings abandoned a successful settlement in Greenland

Vikings would not be the authors of the horned helmets 0:58 (CNN) — Researchers have tried for years to understand what led the Vikings to abandon one of their settlements in Greenland after centuries of success. While some experts suggest falling temperatures may have been the cause, new research suggests cold weather was not a factor in the decision.
Instead, the Vikings faced a new adversary that they could not overcome: drought. A study detailing the findings was published Wednesday in the academic journal Science Advances. The low temperature hypothesis persisted for years due to the presence of the so-called Little Glaciation between 1300 and 1850, when low temperatures persisted in the North Atlantic region. The Vikings established their settlement, known as the Eastern Settlement, in southern Greenland in 985. They cleared the bushes and planted grass for their cattle to graze on. The settlement once had about 2,000 inhabitants. The settlement was abandoned at the beginning of the 14th century. The exceptionally cold climate brought on by the Little Ice Age, which was not a true ice age because it did not occur globally, made Norse farming and herding life unsustainable, according to scientists. But there was no real evidence to support this reasoning about the departure of the Vikings from the area. The ice cores used in previous research to show Greenland’s historical temperature range were collected from more than 1,000 kilometers away and 2,000 meters high. The research team, including (counterclockwise from left) Isla Castañeda, Tobias Schneider, Boyang Zhao, and Raymond Bradley, cores lake sediments in southern Greenland. “Prior to this study, there was no actual site data for Viking settlements. And that’s a problem,” study co-author Raymond Bradley, distinguished professor of geosciences at the University of Massachusetts Amherst, said in a statement. “We wanted to study how the climate had changed near the Nordic farms.” Bradley and the research team headed to Lake 578, which was once near one of the largest clusters of farms in the Eastern Settlement. It is also adjacent to an old Norse farm. Over the next three years, the team collected sediment samples from the lake to build a climate record representing the past 2,000 years. Bradley is shown with some of the sediment samples the team collected from Lake Igaliku. “No one had studied this place before,” study lead author Boyang Zhao, a postdoctoral research associate at Brown University in Rhode Island, said in a statement. Zhao did the research for his Ph.D. in geosciences at the University of Massachusetts Amherst. Samples from the lake were analyzed for elements that could help researchers reconstruct what the climate and environment were like when Vikings lived in the settlement. One of them was a lipid, or organic compound, called BrGDGT. Produced by bacteria, glycerol dialkyl glycerol tetraether branched lipids can be used to identify historical temperatures. “If you have a sufficiently complete record, you can directly relate changes in lipid structures to changes in temperature,” study co-author Isla Castañeda, a professor of geosciences at the University of Massachusetts Amherst, said in an email. release. Lake 578, in southern Greenland, was the main site of the team’s investigation. The second element came from a waxy coating on plant leaves, which helped the researchers determine how much water grass and other plants lost to evaporation. This coating can be used to see how dry it was when the plants were growing. “What we found is that although the temperature hardly changed during Norse settlement in southern Greenland, it got drier over time,” Zhao said. The trend towards a drier climate continued and reached its peak in the 16th century. Drought can reduce the growth of grass, which is a crucial food source for livestock to get through the winter. Norse settlers had already experienced farming and ranching in other harsh environments, such as Iceland and Norway, before coming to Greenland. During the winter, Norse farmers kept their cattle in warm sheds along with stored fodder such as dried grass. In spring, cattle were often too weak to move, so the Vikings herded them back to pasture once the snow melted. A Norse farm stood by the lake, which helped provide an environmental history of the area. These were common practices in times without environmental or climatic stressors, so a prolonged drought coupled with other economic and social pressures could have made the eastern settlement a place the Vikings wanted to leave. The researchers also found evidence that the Vikings’ diet changed over time, shifting from cattle to marine food sources. This forced the Norse to “hunt marine mammals, which was a more dangerous and uncertain activity,” according to the study’s authors. There was also an increase in sea ice, which probably made sea fishing and hunting even more difficult. Currently, southern Greenland continues to experience drought during the summer. Farmers can now import hay, but that was not an option for the Vikings. The study’s authors hope that their research will not only change our understanding of the Vikings, but of the impact climate and the environment have and have had on our lives.