Organic remains of Norse Viking Age settlers, such as wood, bone or ancient DNA, which are highly vulnerable to degradation, may be especially under threat from the effects of future climate change, according to a modelling study in Scientific Reports.

Jorgen Hollesen and colleagues collected 22 soil samples obtained from seven different archaeological sites across the Arctic. The samples contained deposits originating from the three main cultures of Greenland: Saqqaq (2,500 - 800 BC), Dorset (300 BC - 600 AD), and Thule (1,300 AD - present), as well as from Norse Viking Age settlers who inhabited the area. Organic deposits are highly vulnerable to degradation by microorganisms, which is directly affected by soil temperature and moisture content.

The authors used a computer model to simulate different climate change scenarios and the potential loss of organic artefacts due to changes in air temperature and precipitation rates (rainfall, snow and sleet) and their effect on Arctic soil. The model showed that 30 - 70% of the organic carbon contained in buried archaeological remains could degrade within the next 80 years. In the continental inland areas of the region, where many remains of the Norse Viking Age settlers are found, a possible loss of more than 35% of organic carbon could occur over the next 30 years.

With more than 180,000 archaeological sites registered in the Arctic, new methods are needed to detect the most vulnerable sites and help distribute limited conservation resources. The authors suggest that their method may help identify sites that are particularly vulnerable to climate change