The sea ice that caps our planet shrinks and grows every year with the seasons -- but these levels have experienced a disturbing downward trend in recent decades. Following the record-setting low this past summer, a short video from NASA reports on this winter's numbers.
NASA cites a number of factors that affect the thinning cap: warm temperatures, an Arctic cyclone, and massive fracturing in the ice sheet above Alaska. "It doesn't necessarily mean that this year's smaller maximum sets the stage for another record minimum this summer," the narrator explains, "but researchers say the thinning of the ice does make the ice cap more vulnerable to melting events in the future, to the point where we might see virtually ice-free summers in the Arctic Ocean in just a few decades."
For more videos from NASA, visit http://www.nasa.gov/.