The surface ice in the Arctic has been melting to historic low levels every year for the last several years. The graph above shows the first ten years in the National Snow & Ice Data Center records, meant to indicate what Arctic Sea Ice "normally" does as it melts off during the northern warm months. The thick black line is the average over 1981-2010, and grey shaded area shows two standard deviations above and below that line. The blue line tracking along the lower end of the 2SD shaded area is the ice extent this year.