The graph below, which was posted on Twitter by everyone's favorite Swedish statistician, Hans Rosling, shows just how bad things are getting in the Arctic. The gray line shows the 1981-2010 average ice cover in millions of square kilometers. Remember, 1981-2010 is hardly a normal period for the Earth's climate, as all of the hottest years in the recent past took place during those years.
But even taking that abnormal level as a baseline, the past 4 years look pretty bad. The gray area around the gray line shows 2 standard deviations from that baseline, and that boundary has been crossed many times in the past 4 years.For the month of April, the most recent month for which we have data, Dr. Rosling writes: "Arctic Sea ice area in April last 5 years were all lower than 1981-2010 average! April 2014 was lowest of them all." This can't be good.