We still haven't really got out of the deepest solar minimum in a century (solar minimums correlate with colder years) and the Arctic ice sheet is again heading towards the extreme disintegration of 2007, one of the warmest years on record, when the NW passage along the arctic coast of Canada became navigable for the first time ever.
That's what the Italian blog Crisis? What Crisis? has found looking at NASA data (Spanish language version at Rebelión), as it's evident in this image of ice fragmenting at just a little further than 200km from the North Pole:
Which is part of a much larger composite satellite image of the Arctic Sea, where you can see many other cracks as well. The image is dated to June 19th: a month ago.
And something that is also evident in this graph:
It is important to realize that 2007 and 2010 are at the edges of a severe Solar minimum and therefore should not be particularly warm years, rather cold ones. Still the ice sheet is fragmenting like never before. This is of course caused by global warming but also to the accumulative effect produced by it: thinning the ice more and more and reducing the albedo by exposing more water and old bluish ice (we all know that white clothes or walls reduce heating, while black ones increase it). This causes that, while the overall global temperature has only risen by less than one degree Celsius, the change is almost fourfold in the Arctic, which in turn is the cooling central of the planet.
It's a case of positive feedback out of control.
Again this September, most likely, the NW passage will be navigable and we are just beginning the new solar cycle, whose maximum is expected for 2013 (seems it will be a short and mild cycle, or so believes NASA).
But even if the Sun is giving us a hand, the evidence from 2007 and 2010 shows that even with low solar activity and the corresponding relatively "cold" years, the Arctic Sea is melting.