t’s a new low point. The area of the world’s oceans covered by floating sea ice is the smallest recorded since satellite monitoring began in the 1970s. That means it is also probably the lowest it has been for thousands of years. The latest observations from the US National Snow & Ice Data Center in Boulder, Colorado, show how the ice extent has fallen to a new low this year.
In the Arctic, the low in sea ice coverage is a result of both global warming and unusual weather events probably influenced by global warming. But in the Antarctic, the current low in seasonal sea ice could just be a result of natural variability. The extent of Arctic sea ice should be growing rapidly during the northern hemisphere winter. But not only has the Arctic been warming rapidly, this winter repeated incursions of warm air have pushed temperatures even further above average. It has been so warm that on occasions this winter the sea ice coverage has actually temporarily shrunk, as shown by dips in the blue line in the graph below.