New research using environmental DNA (eDNA) suggests that Norse people settled in Iceland nearly 70 years earlier than previously believed, and their arrival may not have been the ecological disaster it’s often portrayed to be. Historical accounts typically place the initial settlement in the 870s, with a narrative of rapid deforestation driven by Viking settlers clearing forests for fuel, building materials, and farmland – a process that has left Iceland with only 2% forest cover today.
Rethinking the Timeline of Settlement
While archaeological evidence, such as a wooden longhouse dating to around AD 874, has hinted at earlier settlement, confirming the precise timeline has been challenging. Now, a team led by Eske Willerslev at the University of Copenhagen analyzed eDNA extracted from sediment cores at Lake Tjörnin in central Reykjavík, one of Iceland’s oldest settlements. By examining layers of volcanic ash, using radiocarbon dating, and analyzing plutonium isotopes, they constructed a timeline of the region from around AD 200 to the present.
A key marker in this timeline is the Landnám tephra layer, ash from a volcanic eruption in AD 877. Previously, most evidence of human occupation in Iceland was found above this layer. However, the new eDNA analysis indicates signs of human activity below the tephra layer, suggesting settlement as early as AD 810. This conclusion is based on an increase in levoglucosan – a compound indicative of biomass burning – and a rise in viruses associated with sewage, both present before the 877 eruption.
A More Nuanced View of Environmental Impact
Contrary to the long-held belief of rapid environmental degradation, the research suggests a more complex picture. The eDNA record reveals an increase in biodiversity coinciding with the initial settlement, indicating the introduction of grazing livestock, hay meadows, and small-scale barley cultivation – likely for brewing beer. Intriguingly, pollen analysis shows an expansion of birch and willow trees during the settlement period, possibly due to deliberate management practices aimed at ensuring access to wood.
“This is the nail in the coffin for that old just-so story of the Vikings getting to Iceland and then, suddenly, ‘oh no, the environment is destroyed’,” says Kathryn Catlin at Jacksonville State University.
While the study suggests that pronounced biodiversity loss didn’t occur until after 1200, the researchers attribute this shift to climate cooling during the Little Ice Age (roughly 1250-1860), compounded by volcanic eruptions and storm surges, rather than solely the actions of the settlers.
Questions Remain
Despite the compelling findings, some experts caution against drawing definitive conclusions. The absence of consistent biomarkers related to human sewage over the intervening centuries raises questions about the scale and nature of the early settlement. Furthermore, while biomass burning is often associated with human activity, natural events like lightning strikes can also cause fires.
The research highlights the potential of eDNA analysis to rewrite our understanding of the past, offering a more nuanced perspective on Iceland’s earliest settlers and their relationship with the environment. It suggests that the narrative of Viking settlers rapidly destroying the Icelandic landscape may be an oversimplification, and that their initial impact was potentially more sustainable than previously assumed.
