Wednesday, October 03, 2012

Polar Opposites

There has recently been some hysteria alarm over the state of the polar ice cap.

Here is a typical story on the phenomena from the NYT:

And here is a graph of satellite data:

The couple of things I think about when I see this data are:

There seems to be a clear trend of decline in Arctic Sea Ice, though the normal seasonal variation is an order of magnitude greater. The trend looks like maybe between 5 and 10 percent decline over a 35 year time-span, while the normal seasonal variation is around 50%!

The other thing is that while it seems to recover every winter season, there may be some value in the Arctic Ocean being navigable for some portion of the year.

Meanwhile, the obvious thing--at least to me, to look at is what is going on in the Antarctic region. If global warming is causing a decline in the Arctic Sea ice, it stands to reason that the Antarctic Sea ice should be similarly declining.

Except it isn't: It is in record high territory.

While the current anomaly is small as a percentage of the whole, note that it is past two standard deviations from the mean.

Besides being on the opposite sides of the Earth, the poles are reversed in their local environment too: In the Arctic, there is an ocean surrounded by land masses. In the Antarctic, there is a continent surrounded by oceans. If you read the articles, you will see that both the melting in the Arctic and the growing ice in the Antarctic can be accounted for by global warming. Somehow though, I suspect that if the Arctic Sea ice was growing and the Antarctic Sea ice was shrinking, there would still be a global warming rationale to account for it.

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