Not the Little Ice Age, but increasing drought would have made life unsustainable.

In the year 985 the Vikings, led by the Norwegian explorer Erik the Red, sailed from Iceland to southern Greenland. Here they successfully founded the first settlements. Some 500 years later, however, the Vikings had vanished just as quickly as they had come. And now scientists think they can finally explain the sudden disappearance of the Vikings.

Vikings

When the Vikings arrived in Greenland in 985, they cleared the land of shrubs and planted grass as pasture for their livestock. The Vikings thrived there and the population reached a peak of about 2000 inhabitants. But at the beginning of the 15th century, the population collapsed like a house of cards.

Little Ice Age

One of the great mysteries of late medieval history is why the Vikings, who had established successful settlements in southern Greenland in 985, abandoned them rather abruptly in the early 15th century. For decades, anthropologists, historians and scientists have believed that the demise of the Vikings was due to the so-called Little Ice Age; the relatively cold period that ravaged Europe from the 1300s to the mid-19th century. That ice age would have made the agricultural life that the Vikings particularly relied on unsustainable.

No data

However, this theory was also in doubt. “Before our study, there was no climatic data of the actual location of the Viking settlements,” explains researcher Raymond Bradley. “And that’s a problem.” Instead, previous studies had examined ice cores taken at a location more than 1,000 kilometers to the north and more than 2,000 higher. “We wanted to study how the climate varied around the Viking settlements themselves,” says Bradley. And that leads to surprising results.

Lake 578

Bradley and his colleagues traveled to a lake called Lake 578. This lake adjoins a former Viking farm and is close to one of the largest groups of farms in the so-called Eastern Settlement; the first and by far the larger of the two areas in Greenland colonized by the Vikings around 985. “No one has studied this site before,” said researcher Boyang Zhao.

Drought

For three years, the researchers collected sediment samples from Lake 578. Then they analyzed it for two different markers. The first can be used to reconstruct the temperature, while the second provides insight into how dry conditions were. The findings are surprising. Because although the consensus has long been that the Little Ice Age drove the Vikings out of Greenland, it now appears that something else was behind the sudden disappearance: It was not the falling temperatures, but increasing drought.

Impaired

“Although the temperature in southern Greenland near the Viking settlement barely changed, we found that it got drier over time,” Zhao said. This must have weakened the cattle considerably. The consequences of the drought must have been serious, the researchers suspect. And this prolonged drought, on top of other economic and social pressures, may have become too much for the Vikings.

The new findings change our understanding of early European history. Because now we finally know what may have been the real reason for the demise of the colonies in Greenland. “It highlights the importance of continuing to explore how environmental factors affect human society,” the researchers conclude.