What’s Really Up With North Pole Sea Ice?

By Andrew C. Revkin

The Arctic Ocean lost much of its old thick sea ice by the 1990s. This animation shows the change from 1981 through 2007, with red designating the oldest (and thickest) ice and dark blue the freshly-formed “first year” ice. Light blue is open water (OW).More background is online. (Credit: Animation from NSIDC courtesy of C. Fowler and J. Maslanik; Colorado Center for Astrodynamics Research)The Drudgeosphere was all pumped up today about the “shock claim” in the (UK) Independent that the sea ice that normally persists year-round at the North Pole (I stood on it in March, 2003) will be replaced by open water later this summer.
Given the unpredictable short-term dynamics up there, which make the ice subject to vagaries of Siberian winds and a mix of currents, a lot of polar ice experts tell me it’s pretty much impossible to make such a prediction with high confidence. In fact, the Independent’s story — the opening sentences and headline at least — go way beyond what Mark Serreze of the National Snow and Ice Data Center tells the reporter. As early as May, ice experts were putting good odds on having open water at the North Pole.

One way or the other, it’s clear that, by the end of the 1990s, the veneer of ice on the Arctic Ocean had shifted to a far more tenuous state, with ever less thick, years-old ice like the floes I camped on when I went with the team setting up the annual North Pole Environmental Observatory. The animation above shows that the ice was flushed out, not melted.

Most of the seasoned Arctic ice experts I’ve canvassed for recent stories see the region exhibiting a mix of natural variability in the ice (like the flushing process) and a long-term trend toward less of it in summer, and more of it being fresh-made each season, and thus thin and easy to melt. Most also are convinced the change is now at least partly driven by human-caused global warming.
Their various projections are laid out in monthly Sea Ice Outlook reports. Right now the odds are essentially even on a 2008 match for the dramatic ice loss last year.
Here’s what trends looked like leading to last year’s remarkable ice vanishing act:

Many foes of greenhouse-gas restrictions and skeptics on the strength of climate science have pointed out that the world’s total sea-ice area hasn’t changed appreciably when you add up the ice in the Arctic and the sheath of sea ice that annually forms in winter around Antarctica (but disappears in austral summers). The Antarctic sea ice (distinct from the massive ice shelves fringing the continent and ice sheets inland) has, in fact, been expanding in recent years. You can compare the differences by clicking here for Arctic and Antarctic trends.

But scientists studying trends at both poles say there is nothing inconsistent with the intensifying greenhouse effect. William Chapman, who maintains the helpful Cryosphere Today Web site at the University of Illinois, Urbana-Champaign, sent me an email this morning reminding me of a 2005 study that projects more Antarctic sea ice (by volume) in a warming world.

“Yes, sea ice seems to behaving as the consensus of the climate models have been projecting - more rapid and larger response in the northern high latitudes than anywhere else, flat to possible increase in [southern hemisphere] sea ice as warming takes hold,” he wrote.

Here’s where the extent of sea ice in the Arctic stands now in relation to the average tracked between 1979 and 2000, and the remarkable ice loss in 2007:

The extent of Arctic Ocean sea ice is declining at a pace nearly matching last year’s unforeseen plunge.


205 comments so far...
1.June 27th,
2008

1:22 pm “Yes, sea ice seems to behaving as the consensus of the climate models have been projecting - more rapid and larger response in the northern high latitudes than anywhere else, flat to possible increase in [southern hemisphere] sea ice as warming takes hold,” he wrote.

And this also is perfectly in line with global warming not caused by humans as well. In fact, I have yet to see a serious cause of global warming mentioned where this doesn’t manage to fit the prediction. Note I am not including Hansen as a serious source of science in this, as he predicted that both poles would be melting at once.

The things to watch for: If the ice starts to melt and keeps melting. If warmers are right, then the Antarctic is going to start melting soon enough and won’t stop. If the skeptics are right, then the arctic might actually freeze over in a few years.

Incidentally, if a report I read from one scientist is right, then the antarctic is not to be relied on for any measurements. It won’t start melting for another 10k years no matter who’s right according to that guy.

— Posted by Lilith Taveril
2.June 27th,
2008
1:23 pm Surprise volcanoes and heat vents in the Arctic!

But I am sure our intrepid climate modelers have that included right?

http://www.scienceandthesea.org/index.php?option=com_co ntent&task=view&id=30&Itemid=10

[ANDY REVKIN says: No real surprise these days. The volcanic activity beneath the Arctic Ocean there been known for awhile now. Keep in mind it’s two miles below the sea ice, with thick intervening layers of water that don’t exchange much heat.]

— Posted by Bob B
3.June 27th,
2008
1:23 pm Andy, thanks for a balanced article. It looks like we’re tracking last year closely to this point. The Drudge article startled me yesterday because I hadn’t heard anything at all recently about the Arctic ice. I don’t understand, though, how any of this is consistent with the AGW models. Isn’t it just weather, like the below average temperatures in North America this past winter, which certainly didn’t disprove AGW?

— Posted by E. O'Neal
4.June 27th,
2008
1:28 pm As a matter of fact, the climate experts who have long predicted global warming and loss of Arctic ice also predicted… as long as 20 years ago!… that Antarctic sea ice would NOT be decreasing around now. People who make successful predictions are worth listening to.

— Posted by Spencer
5.June 27th,
2008
1:44 pm the earth is pretty much doomed now.

— Posted by noob1
6.June 27th,
2008
1:46 pm “Arctic Ocean Getting Warm; Seals Vanish and Icebergs Melt.”

Washington Post, Nov 2, 1922

Nothing new.

[ANDY REVKIN suggests: Please re-read my earlier coverage of this question to get a solid view that things now are quite new, even in the context of the Arctic warmup in the early 20th century.]

— Posted by Jepe
7.June 27th,
2008
1:57 pm Other sources cite significant volcanic eruptions on the sea floor below the North Pole (erupted in the last 15 years). There obviously COULD be a correlation between volcanic eruptions and melting ice.

Can we all just investigate this and search for THE TRUTH, instead of trying to prove what you already believe to be true?! I’m really tired of all the poitics in “scientific” reporting.

— Posted by Drewbie3939
8.June 27th,
2008
1:57 pm That graph is VERY misleading in the context of the story! In today’s fear about global warming, it is criminal for the NY Times to use this graph to suggest the years 2007 and 2008 indicate a definite and prolonged warming trend. Anyone with any brains knows the “AVERAGE” of the years 1979 through 2000 will have a significant number of years below the average. That’s why it’s called and average! The NYT editor for allowing this graph to be published should be prosecuted for attempting to generate fear among his readers.

[ANDY REVKIN says: Wow, a lot of recommendations for prosecution this week. I think you’ve misread the (potentially confusing) labels provided by NSIDC. Those averages are for each month. In other words, the reading for May 2008 is compared to the ice extent from May 2007 and also to the average, for the month of May, from 1979-2000. That’s why it’s significant. ]

— Posted by Bob ODonnell/Woodstock