Interactive: When will the Arctic see its first ice-free summer?
Since satellites first began monitoring the Arctic in 1979, the average area covered by sea ice has shrunk by at least 40%. The average thickness of the ice has fallen by more than half over the same time period.
These rapid changes have left climate scientists facing an urgent question: when will Arctic sea ice disappear?
The pace of change is most stark in September, the end of summertime in the Arctic. Each year, Arctic sea ice goes through a seasonal cycle, growing in area and thickness through the cooler winter months before shrinking back again as temperatures rise in the spring and summer.
The point at the end of summer when sea ice reaches its lowest level for the year is known as the “sea ice summer minimum”. This year, the sea ice minimum is the second smallest on record, beaten only by the sea ice low seen in 2012.
“The really warm summer in the Arctic has really had its impact on the ice,” says Prof Markus Rex, an atmospheric scientist from the Alfred Wegener Institute (AWI). Rex is the leader of MOSAiC, one of the largest Arctic research expeditions ever attempted. (Carbon Brief recently joined the year-long expedition for its first six weeks at sea.)
Rex has spent the months leading up to the expedition closely following Arctic weather reports. The Arctic was hit by higher-than-average temperatures in May and July 2019, which likely worsened the pace of summer sea ice melt, he says.