I heard of all kinds of horror stories about methane seeps in the Russian Arctic, lakes catching fire and so on, but I haven’t followed up on it. I like the sea ice survey data because

1) it is consistent and comparable, all from the same sensor platform

2) we have uninterrupted records now for 30+ years

3) clear and unmistakeable trends are distinctly visible, and have been documented for every month of the year for the last 33 years.

4) we have statistical data and imagery which can be compared side by side for every month in every year

5) The sea ice extent, particular at the height of the melt season from Jun-Oct, peaking in mid-Sep, is highly sensitive to even minor changes in global temperature, but the area under consideration is huge, so local meteorological effects and variations tend to even out and damp out noise over time.

6) no heavy-duty analysis or interpretation is required. Just look at the millions of square km of ice that melt, and how it changes over time. This is not a subtle effect. It is quite dramatic, and there is no sign it is going to turn around any time soon.

Essentially what you have are 3-dimensional datasets, with ice extent, time-of-year, and calendar year axes you can display the data on partial derivatives along any axis you like. A tiny change in temperature gives you a huge change in sea ice extent. Thick continental ice, like Greenland or Antarctica, has much more thermal inertia and reacts much more slowly. Sea ice is the canary in the coal mine.

Go here:

http://nsidc.org/arcticseaicenews/

and click on the “Archives” Select Month button to get detailed looks at the last two years. Pay particular attention to the comparisons of each month in the melt cycle
with the same month from previous years, and the satellite map that goes for that month.

Here is this latest entry in the Archive, for Aug 2012

http://nsidc.org/arcticseaicenews/2012/08/

These are not random outliers and anecdotal information. These are statistical curves and they all dip in the same direction.

Its the hippy-dippy weather, man, from your hippy-dippy weatherman. And it don’t look very promising.