How Much Sea Ice?

The New York Times reported yesterday that the Arctic Ocean sea ice has reached a new record low. “Record low” Arctic ice this summer depends upon what data is used. This year, low values are in part a result of a very unusual storm in early August that broke up a large amount of ice northwest of Alaska. When this remaining ice is counted—as it should be—the total ice is about a million square kilometers greater than in the record low year of 2007. It is also worth noting that sea-ice coverage in the Southern Hemisphere continues to increase in a statistically significant fashion, as has been noted for decades. 

A detailed summary of the various measurements of sea ice can be found here.