For months, the deniers have been extolling the fact that the Arctic sea saw record refreezing last fall. And they have been claiming that this somehow fits into the absurd claim that the planet is now in a major cooling trend.
But back in the real world, the planet keeps warming, and the Arctic is taking the worst of it, which could lead to potentially catastrophic methane emissions from the tundra, as noted here. The National Snow and Ice Data Center just reported:
Arctic sea ice still on track for extreme melt
Arctic sea ice extent has declined through the month of May as summer approaches. Daily ice extents in May continued to be below the long-term average and approached the low levels seen at this time last year. As discussed in our last posting, the spring ice cover is thin. One sign of thin and fairly weak ice is the formation of several polynyas in the ice pack.
No surprise that a recent survey of leading experts with the international Arctic science community found they expect a "continuation of the recent trend of sea ice loss" this summer. How exactly does this year's sea ice extent compare with last year and with the 1979-2000 average? NSIDC has a great figure (click to enlarge):
Although ice extent is slightly greater than this time last year, the average decline rate through the month of May was 8 thousand square kilometers per day (3 thousand square miles per day) faster than last May. Ice extent as the month closed approached last May's value.
OK, so the ice area is shrinking fast. What about thickness -- an equally important determinant of how fast the ice will disappear?
Multi-year ice continues to be low
The relative lack of thick, resilient multi-year ice in the Arctic discussed in earlier postings finds further support in the latest analysis from the United States National Ice Center (NIC). NIC uses a variety of satellite imagery, expert analysis, and other information to provide information on the amount and quality of sea ice for ships operating in the Arctic. NIC scientist Todd Arbetter suggests that much of the first-year ice is likely to melt by the end of summer, saying that despite the total ice extent appearing normal, the relative amount of multi-year ice going into this summer is very low when compared to climatological averages. NIC has found that the relative fraction of multi-year ice in the central Arctic has plummeted since the mid-1990s, creating an Arctic prone to increased melt in summer. Arbetter said, "This may be a primary reason for record summertime minimums in recent years."
How hot is it in the Arctic Ocean?
Average Arctic Ocean surface air temperatures in May were generally higher than normal. While anomalies were modest (+1 to 3 degrees Celsius, +2 to 5 degrees Fahrenheit) over most of the region, temperatures over the Baffin Bay region were as much as 6 degrees C (11 degrees F) above normal. The atmospheric circulation in May was highly variable. The first half of the month saw strong winds blowing from east to west over the southern Beaufort Sea. This wind pattern probably contributed to polynya formation near Banks Island and along the northwestern coast of Alaska.
The Study of Environmental Arctic Change (SEARCH) -- (Note to self: Next time a good acronym is needed, talk to some Arctic scientists) -- prepared its May Sea Ice Outlook report for the September 2008 sea ice extent "based on a synthesis of 19 individual outlooks from the international arctic science community." They found:
Of the individual responses that included quantitative outlooks, three (3) suggest a return toward the long-term trend of summer sea ice loss; six (6) anticipate the 2008 extent to be close to the 2007 record minimum; five (5) respondents suggest additional ice loss compared to the 2007 minimum. None suggested a return to the historical average (mean 1979-2000 September values) of 7.0 million square kilometers.
I think it's going to get harder and harder to find people to take my bet.
This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.
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Comments
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Mace Posted 8:49 am
13 Jun 2008
So the net global sea ice is up by +.4 M sq km.
Do you think these are counter trends, some kind of feedback loop or unrelated?
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christophersj Posted 10:45 am
13 Jun 2008
Every report I have seen about any growth in sea ice has also shown that it was abnormally thin and would melt at the first sign of even "normal" warmth.
This makes the denier's arguments as thin as the new ice.
-Christopher S. Johnson
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Pangolin Posted 1:31 pm
13 Jun 2008
Drought is normal in California and tornado weather is normal in the Midwest but the weather this year if freaking weird. If people can't put 2 and 2 together by November in this weather there just isn't any hope.
Are people making the connection or are they just hoping the train to the big rock candy mountain makes one more run and they get a ticket?
Any ideas?
Put the Carbon Back
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Tasermons Partner Posted 2:25 pm
13 Jun 2008
I hadn't heard 'bout the South gainin' ice, but I did read a report recently suggesting that the melt effect was occuring at a slower rate in the Antartic due to...of all things...the hole in the ozone that's been caused by CFCs and other pollutants.
Turns out it may be causing a "shield" effect.
Of course, a giant hole in the ozone presents it's own environmental problems...
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Craig Allen Posted 2:27 pm
14 Jun 2008
The Arctic is an ocean surrounded by land. The Antarctic is a continent surrounded by an ocean and is circumnavigated by the massive Circumpolar Current. The climate dynamics are therefore quite different and we expect and are seeing very different trends.
Apparently there has been little or no significant trend in Sea Ice in the Antarctic taken as a whole and the sea ice extend is much more variable than that in the Arctic. But there are significant trends in particular regions, some toward more ice and some toward less.
This post on Ice Shelf Instability at the RealClimate website has lots of interesting information. Be sure to read through the comments - there is lots of interesting stuff there that relates directly to your question.
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GreyFlcn Posted 3:41 pm
14 Jun 2008
Turns out it may be causing a "shield" effect.
Well it's not really a shield, it's more of a "vent".
http://www.sciam.com/article.cfm?id=mending-ozone-worse-f ...
The catch-22 of course being that the CFCs which caused the Ozone hole, are themselves also tens of thousands of times more potent as GHGS than CO2.
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GreyFlcn Posted 4:00 am
15 Jun 2008
The west side of it is collapsing.
In winter.
http://www.sciencedaily.com/releases/2008/06/080613104743 ...
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Mace Posted 7:47 am
15 Jun 2008
Set the Hemisphere to 'Southern', set the image to 'extent anamolies':
http://nsidc.org/data/seaice_index/archives/image_select. ...
The trend shows a 1.8% growth per decade but with a variation of +/- 2.2%. As noted, there is wider variation in the Southern Hemisphere than in the north.
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Mace Posted 8:04 am
15 Jun 2008
http://www.esa.int/esaEO/SEMG58VG3HF_planet_0.html
Keep in mind this 560 sq km shelf break is .1% of the total sea ice increase at present. That does not explain the increase in sea ice of 800,000 sq km.
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Mace Posted 4:32 pm
15 Jun 2008
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=06&a ...
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retroproxy Posted 5:23 am
06 Dec 2008
Here's a graph showing data of ice extent back to 2002: http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
And finally a graph showing the rate of CO2 rise alongside the temperature trend since 2002: http://icecap.us/images/uploads/MSUCRUCO2.jpg
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