Climate change and religion may explain why Viking farmers abandoned lands in Greenland in the 1300's, a Canadian researcher said at a lecture Thursday.

Before a full audience at the UAF Museum of the North, Charles Schweger, a geology professor at the University of Alberta in Edmonton, said a miniature ice age had ruined farming conditions for Viking settlements in Greenland. Rather than adapt, the Vikings focused more on religion while neglecting the farms.

"Humans are naturally conservative, and religion protects people from a need to change in response to something like climate change," Schweger said.

The Vikings formed two settlements in Greenland following its discovery by Erikk the Red in 982. The archeological record shows they both relied on farming and were heavily religious.

For 400 years, the settlements prospered, only to be abruptly deserted between 1350 and 1410.

Anthropologists and archaeologists have tried to explain the settlements' desertions through a variety of theories. The most popular one speculated that poor farming practices destroyed the soil, while religious pressure to support the church reduced farming manpower causing the Vikings to abandon the Greenland settlements. Author Jared Diamond cited this theory in his book "Collapse."

But Schweger found contradictory evidence while evaluating soil chemistry and mineralogy during an excavation of the Garden Under Sandet, or GUS, a site at one of the Viking settlements. After abandonment, the site was buried under flood plane alluvium, silt deposited from river flooding and immaculately preserved.

"I was able to identify that these farmers were very good farmers. They did not destroy their land. Our samples indicate that they actually improved the quality of their soil," Schweger said. "That soil got me thinking, there is no evidence that the people were anything other than good farmers."

Schweger became involved with the site in 1995, joining the excavation led by the Danish National Museum and the National Museum of Greenland to study the geology and paleoecology of the region.

Schweger looked into other factors that could have forced abandonment. From soil samples he moved on to investigate the site's water source, a dirty river with glacial run off and the topography of the valley.

Valley bottoms and flood plains were necessary to support the farming practices of the Vikings, explained Schweger. Because of their moist nutrient-rich soil, valley bottoms were used to grow hay for the farm livestock and were the farm's most important areas.

Schweger realized that the soil composition in the valley differed from the excavated fertilized layers 1,000 years ago. He noticed the valley bottoms were no longer nutrient rich and were buried under layers of alluvium deposited from rivers in the flood plain.

The increase of sedimentation on the flood plain was likely due to the increase in glacial run off from a growing ice sheet, a direct result of the beginning of the little ice age, Schweger said. This change in climate destroyed fresh water sources and the precious grounds used for growing hay.

"I attribute the abandonment of the Greenland settlement to the impact of the little ice age on glacial valleys," he said.

The growing ice sheets destroyed land and complicated farming practices adding stress on the settlements. A prevalence of religious icons in the archaeology spurred Schweger to look at the significance of religion in the decision to abandon the settlements.

The pressure of climate changes pushed early societies to reaffirm their self-identity through religion. Schweger argues that the desire to resist change and focus on religion was so great that the Vikings were unable to successfully adapt to continue farming the land.

Modern research indicates that self-identity and ideology are a set of beliefs that more or less define who people are and how they think about themselves and the world.

Schweger related the ideologies at GUS to modern farmers. He described Midwest farmers who cling to failing farms, resisting change at their own expense in order to preserve their self-identity. Schweger noted that many Midwestern people describe and identify themselves as farmers despite the fact they may no longer work or own a farm.

In many cases, ideology is expressed by religion during periods of trial people try to reinforce their ideologies and turn to religion, Schweger said.

"Rather than say religion was the cause of abandonment, I would say that poor farming was the result of increased religion encouraged by the stress of climate change. And the necessity to abandon the farms strengthened their religion," lectured Schweger.

Stephen Krohn, a master's degree student, painter was surprised by what he learned. "I came to see the images and artifacts of the Vikings," he said, "and I learned about the processes of geologic change and the role that climate played in the survival of early Viking civilizations."