Satellites measure the extent of sea ice in the Arctic every day. The data show that the ice-covered area has been shrinking for decades — an effect that further accelerates climate change. In the coming decades, something will happen that hasn't occurred for millions of years: the Arctic will be virtually free of sea ice.

The graph on the right shows the extent of the ice over the course of a year. The fact that there is less ice at the North Pole in summer than in winter is normal. But both in summer and in winter, the ice has been declining for years. The years from 1980 onwards, when there was still more ice overall throughout the year, are shown in very light blue. The more recent years, shown in a slightly darker blue, are mostly below them.

On Saturday, 27 January, the extent of Arctic sea ice was 13.0 million square kilometres. That is 3.8 per cent less than the average for the period 1981 to 2010.

Why 1981 to 2010 is used as the reference period… find out more at ndr.de!

by Lalon Sander