Or it could be ...

Huh. I hadn't even heard this bit, but it checks out.

Apparently a bunch of geothermal heat (and CO2, but I digress) has been released into the Arctic Ocean underneath the ice cap ... some huge explosions thought not possible before because of the great depth of the water there -- along a tectonic spreading joint called the Gakkel Ridge. This ridge runs down the middle of a deep basin whose western edge runs, for most practical purposes, right under the north pole.

So a series of huge volcanic eruptions as recent as 1999 have ... heated the Arctic Ocean under the polar ice cap. (You don't suppose something like that might interrupt the "delicate balance" of oceanic circulation in the arctic, do you ?) And ... the age of the ice in the icecap has dropped from 20% 6 years or older in the 1980's to 3% in 2008.

I'd like to see a chart correlating the drop the amount of old ice with ... earthquake activity in the region just north of Greenland. We didn't, until recently, know they were related to undersea volcanic eruptions. This article says the scientists say that the heat released isn't contributing to the melting of the polar ice cap (I'd like to know what their reasoning is. It's a lot of heat in a basin with a relatively closed circulation -- and they've only studied a very small portion of the ridge. Remember "delicate balance"? Volcanic explosions more massive than anything we've ever seen?) But they do say the CO2 released is affecting the atmospheric CO2 concentrations and thus global warming. But they can't (won't?) guess how much ... out loud.

In addition (not surprisingly) there's an oscillation pattern in the Arctic ... like the one in the southern Pacific that produces El Niño (the Southern Oscillation) known as the Arctic Oscillation. And it just so happens that last summer while this was going on it was just getting over going this-a-way, and this winter is switching around to go that-a-way (that's what oscillations do). When that happens, there's a loss of the fresher water that forms the halocline layer, which protects the ice from warmer, saltier waters below. And there's apparently enough heat in those waters below to melt the entire ice cap, according to those who study these waters.

I'd like to read more on the volcanic activity and the heat and CO2 amounts involved in relation to the total earth carbon budget.

At any rate, suffice it to say there are likely other forces at work that could well explain what's going on with the (north) polar ice cap, AGW theory or no. And to say we know what "normal" is after 60-100 years of records is a bit presumptuous.