Monday, January 12, 2009

Arctic Blues, or, Our Blue Arctic

The National Snow and Ice Data Center (NSIDC) issued a report a few days back that I've been meaning to get to. Most often when I put these post ideas on the back burner and allow my compulsive reading to consume all my time, the articles start to seem dated and obsolete, and I just forget about them. On occasion though, someone will do a much better job of blogging about it than I could hope to do. Happily, this has just happened.

Dr. Jeff Masters, at his "Wunderblog," has posted a lengthy but excellent piece that starts with the sentence, "The top climate story of 2008, as it was in 2007, was the extraordinary summertime sea ice retreat in the Arctic." I'm guessing that most people heard about the 2007 retreat, but if they had heard about this past summer's ice retreat it was in the context of being so much less extreme than 2007's. Indeed, this past summer and fall's data seems to me to have received the most attention from climate change deniers. And it is true that the minimum 2008 ice coverage was 9% more than 2007's minimum.

It's also true that the 2008 value was 34% below average. And that in 2008, for only the second time in recorded history, the fabled Northwest passage (between the Arctic Ice cap and Canada) was open: you could sail from the Atlantic to the Pacific Ocean north of Canada. It's also true that the ice thickness was probably at a historical minimum, which means the ice volume was also at a record minimum. Which in turn means it will melt off that much faster this coming summer. And the final truth (at least right now; I can only stand so much truth at a time) is that for the first time in history, the Northeast passage was open north of Russia! For the first time in history, probably since before the last ice age, the Arctic was an island!The above graph, from the Wonderblog piece, shows with black lines the predictions of a variety of models with respect to Arctic ice retreat looking forward to 2100 AD. The bold red line shows the actual observed data. If you look at the average prediction, the dark black line running through the middle of the plots, and compare it to the observed data, where we are as of 2007-08 is about where our best suggestions said we might be about 2050. Quite a number of the more optimistic predictions suggested that by 2100, we wouldn't be where we are in reality over 90 years earlier.

We can pretty much kiss the image of Earth we grew up with, the one where both the polar regions are white, goodbye. Sooner than anyone thought possible, let alone likely, the north pole will be blue, open ocean, except for a few winter months.

And in other news, Santa Claus has just purchased the island of Tasmania from the Australian Government.

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