New research, conducted by the Niels Bohr Institute at the University of Copenhagen and published in the scientific journal Climate Dynamics, maintains that the sea ice in the Arctic sea between Greenland and Svalbard has reached the smallest size it has been in 800 years.
The research combined information about the climate found in ice cores from an ice cap on Svalbard and from the annual growth rings of trees in Finland. The data about the ice cover was gathered from the logbooks of whaling- and fishingships datign back to the 16th century as well as from records from harbours in Iceland, where the sea ice coverage has been recorded since the end of the 18th century. By combining these two sets of information the reserachers were able to track the sea ice all the way back to the 13th century.
The sea ice has been at the minimum also before, first in the late 13th century and later in the mid 17th and mid 18th century. The researchers maintain, however, that these periods were in no case as persistent as the decline of the sea ice in the 20th century when the ice diminished 300 000 square km in ten years. The sea ice has been at its largest from the seventeenth to the nineteenth centuries, during a period called the Little Ice Age.