Yet Another Incorrect IPCC Assessment: Antarctic Sea Ice Increase
by Chip Knappenberger
March 8, 2010
Another error in the influential reports from the Intergovernmental Panel on Climate Change (IPCC) reports has been identified. This one concerns the rate of expansion of sea ice around Antarctica.
While not an issue for estimates of future sea level rise (sea ice is floating ice which does not influence sea level), a significant expansion of Antarctic sea ice runs counter to climate model projections. As the errors in the climate change “assessment” reports from the IPCC mount, its aura of scientific authority erodes, and with it, the justification for using their findings to underpin national and international efforts to regulate greenhouse gases.
Some climate scientists have distanced themselves from the IPCC Working Group II’s (WGII’s) Fourth Assessment Report (AR4), Impacts, Adaptation, and Vulnerability, prefering instead the stronger hard science in the Working Group I (WGI) Report—The Physical Science Basis. Some folks have even gone as far as saying that no errors have been found in the WGI Report and the process in creating it was exemplary.
Such folks are in denial.
As I document below, WGI did a poor job in regard to Antarctic sea ice trends. Somehow, the IPCC specialists assessed away a plethora of evidence showing that the sea ice around Antarctica has been significantly increasing—a behavior that runs counter to climate model projections of sea ice declines—and instead documented only a slight, statistically insignificant rise.
How did this happen? The evidence suggests that IPCC authors were either being territorial in defending and promoting their own work in lieu of other equally legitimate (and ultimately more correct) findings, were being guided by IPCC brass to produce a specific IPCC point-of-view, or both.
The handling of Antarctic sea ice is, unfortunately, not an isolated incident in the IPCC reports, but is simply one of many examples in which portions of the peer-reviewed scientific literature were cast aside, or ignored, so that a particular point of view—the preconceived IPCC point of view—could be either maintained or forwarded.
Background
The problems with the IPCC’s handling of the trends in Antarctic sea ice was first uncovered and presented a week or two ago in an article posted over at the World Climate Report—another blog with which I have been involved with for a long time.
…
The First Order Draft of Chapter 4 contained the following illustration of Southern Hemisphere sea ice, along with the caption “Sea Ice extent anomalies … the Southern Hemisphere based on passive microwave satellite data… [l]inear trend lines are indicated for each hemisphere….the small positive trend in the Southern Hemisphere is not significant. (Updated from Comiso, 2003).”
Figure 1. Figure 4.4.1b from the IPCC AR4 Chapter 4 First Order Draft.
Notice two things, 1) the figure depicts monthly ice extent anomalies from November 1978 through October 2004, and 2) the trend through them seems to be statistically significant (i.e. the confidence range does not include zero), given in the illustration as 9089.2 +/- 2970.7 km2/year or 0.735 +/- 0.240%/dec.
Yet, for some reason, the accompanying text claims that the trend in Figure 4.4.1b is insignificant (AR4 First Order Draft, page 4-14, lines 9-10):
The Antarctic results show a slight but insignificant positive trend of 0.7 ± 0.2% per decade.
This inconsistency was brought to the IPCC Chapter 4 authors’ attention by several IPCC commenters. Commentor John Church wrote “I do not understand why this trend is insignificant – it is more than three times the quoted error estimates” and Stefan Rahmstorf wrote “How can a trend of 0.7 +/- 0.2 be ‘insignificant’? Is not 0.2 the confidence interval, so it is significantly positive?” The IPCC responded to both in the same manner “Taken into account in revised text.”
And boy did they ever!
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I can accept this statement, but does the same apply to global temperature anomalies? It would appear to me that there is a similarly large standard deviation in that data, too.
“Max Hugoson (14:05:08) :
Sorry, the S.D. of this data is TOO HIGH. There is NO statistically discernable trend in this data.[…]”
Oh, i guess we could use your argument very well to argue against a statistically significant rise in worldwide temperatures… just take monthly figures… Is that the official party line? Thanks!
Why is Arctic sea ice trend of 2.9% per decade widely accepted while the positive 3.1% trend in Antarctica is not?
From NSIDD:
Sea ice extent in the Antarctic has been unusually high in recent years, both in summer nd winter. Overall, the Antarctic is showing small positive trends in total extent. For example, the trend in February extent is now +3.1% per decade.
The average ice extent for February 2010 was the fourth lowest February extent since the beginning of the modern satellite record. It was 220,000 square kilometers (85,000 square miles) higher than the record low for February, observed in 2005. The linear rate of decline for February is now 2.9% per decade.
Max Hugoson,
Question as someone who admittedly tried his best to learn as little as possible during my statistics classes while getting an A in it.. I think what you’re saying is that because of the amplitude of the signal up and down the trend is statistically insignificant. Am I reading you right?
>>Reply: No. We explicitly recommend not calling people derogatory names. I personally use the term AGW proponent. ~ ctm.
Fair enough. But I’m done calling these AGW advocates scientists. That’s insulting to actual scientists.
Well any day now the great Arctic Sea Ice Melt Off of 2010 should begin; well who knows; maybe not since the temperature is still -30 deg C up there.
Well it can’t hod off forever so one of these days the fun should start; maybe they need to send some ice breakers up there to start things off.
As to the Antarctic sea ice growth; how much of that is due to the whole Antarctic ice sheet slipping off into the ocean, versus growth of new marginal sea ice from freezing.
To what extent is the march of the land ice assisted by the increased weight of deposited ice up in the highlands; and how much lowering of the ocean level occurrs because of that deposition.
Does anybody know just what differential land ice melt vs deposition from the ocean, is expected to occur while the sea level is rising this 20 ft that we are all waiting for ?
I hear a lot of talk of the slideing and melt-off, due to global warming, but nothing much about increasing precipitation up higher going on at the same time.
BUT… BUT… 100,000 km2 a decade is like 5 times the state of Texas!
So in 20 years we’ve net gained 10 times Texas on top of the peninsular loss of 1 Texas… but the loss is significant and proof of AGW. The gain is statistically insignificant and probably just weather. What don’t you get about that?
/sarcoff
Replace Texas with New Jersey and read the USGS Ferrigno/NPR article from a few days back if you don’t get the joke
If the increase was the other way round then read “it’s worse than we thought.”
Here is a challenge for AGW re: scientific method, predictions and falsibility of a theory.
http://www.theresilientearth.com/?q=content/cherry-picking-black-swans-and-falsifiability
“”” crucilandia (15:28:30) :
Why is Arctic sea ice trend of 2.9% per decade widely accepted while the positive 3.1% trend in Antarctica is not?
From NSIDD:
Sea ice extent in the Antarctic has been unusually high in recent years, both in summer nd winter. Overall, the Antarctic is showing small positive trends in total extent. For example, the trend in February extent is now +3.1% per decade.
The average ice extent for February 2010 was the fourth lowest February extent since the beginning of the modern satellite record. It was 220,000 square kilometers (85,000 square miles) higher than the record low for February, observed in 2005. The linear rate of decline for February is now 2.9% per decade. “””
Well would somebody like to clarify how come the trend in February is now at +3.1% per decade, while the linear rate of decline is actually 2.9% per decade (as in minus trend)
I don’t get it; up or down; which is it ?
The first scientist submitting to this website with a curved line should get the Nobel Prize.
pft
Quote”This month to month, year to year, even decade to decade comparisons is not very productive., and takes away from the real issue, the science behind warming attributed to CO2 (more specifically, anthropogenic CO2)”
I agree
I don’t think anyone really believes we can measure temperature or ice, or anything else for that matter.
When the past records have all been so manipulated, whatever the temperature, ice, or anything else is now, does not matter.
If you told people the moon was made out of green cheese, they would ask you to prove it.
But yet, tell people we’ve reached a tipping point and they fall for it.
What is really keen here, is that all these “gates” in the IPCC reports were spoken of and complained about at the time, or even before the report’s release. Only NOW, following Climategate, are they being taken up.
DirkG – is this maybe Antarcticagate II? (Although what do we do when the Roman numerals become unwieldy?)
I am beginning to wonder if the IPCC has any correct predictions in the 2007 annual report. Who reviewed this document? Did they think that no one would read it? Did they read it? This is the group that wants to set standards for CO2 production based on very shoddy science.
terry46,
Not sure on the details but there was a submission freeze for AR4 in 2005 or 2006, which was published in 2007. The research used for it was probably didn’t use any data past 2004 and this post covers what was used and discussed for AR4.
I believe Antarctic sea ice coverage has continued its up trend since.
bob (15:08:45) spoke:
Just because the confidence range does not include zero, does not mean that the result is statistically significant.
OK bob, please don’t leave confusion in your trail. Since you object and speak as if you have statistical knowledge, please post back stating exactly what would mean it has significance. What is the significance statistical threshold you weigh this article against?
May I ask a question?
Why are so many getting so worked up over a degree C of change?
The temperature here has swung over 47 degrees F today. No one has died. Nothing has been destroyed. It’s a huge swing and it’s harmless.
Yet I’m supposed to get myself worked up over a 3 degree C or thereabouts change in average?
Please help me understand. None of the AGW proponent sites I’ve visited has been willing to answer.
Thanks! And another great expose on the fraud that is the IPCC.
Arctic trend -2.9%/dec (loosing)
Antarctic trend +3.1%/dec (gaining)
Yo, ctm. . .seriously, why *is* “warmers” or “warmists” considered derogatory? I get it with “Deniers”, but for the life of me I can’t figure out why “AGW proponent” is okay and “warmers” isn’t. If it were, say, “brimstoneites” or somesuch I could see it.
Labels are handy, y’know, and for far more than insult. That’s why the race bothered to invent them.
AEGeneral (14:49:27) :
“Forgive me if it’s already been answered before, but why has it taken so long for the above-mentioned as well as other recent inaccuracies to be discovered?”
The same reason it takes a husband years to discover his wife is having an affair. There is a sense of trust, and the various excuses seem plausible.
Once the trust is broken, then he finds hundreds of bits of evidence that had been there all along.
perhaps they are just rotten ice-holes
NickB. (15:41:53) :
“Replace Texas with New Jersey and read …”
Even with 31 New Jerseys a Texas make not! <):-)
Oh dear, not again? (sigh)
8 March: Miami Herald: CAMMY CLARK: Big chill killed large swathes of coral, scientists say
Analysis of the data collected by 31 scientists from 13 organizations has not been completed to determine the amount of coral damage throughout the island chain. But James Byrne of The Nature Conservancy said it is more severe than the die-off from South Florida’s last cold-water event in 1977 that killed hundreds of acres of staghorn and elkhorn coral.
Microbiologist Kim Ritchie of Mote Marine Laboratory in Sarasota saw many casualties of the recent cold, including boulder-sized star and brain corals that she estimated were growing when Henry Flagler built Florida’s overseas railroad a century ago.
“It’s very sad,” she said.
Scientists know much more about the affects of extreme warm water on corals…
http://www.miamiherald.com/2010/03/08/1519444/big-chill-killed-large-swathes.html
8 March: Business Week: Simon Lomax: EPA Has No Plans for Own Carbon-Trading Program, Jackson Says
Editors: Romaine Bostick, Larry Liebert
Some people are “over reading” the EPA’s budget request for fiscal 2011, EPA Administrator Lisa Jackson said in remarks at the National Press Club in Washington.
Cap-and-trade legislation, which is stalled in Congress, would create a market for carbon dioxide permits that lets companies buy and sell the right to pollute. The agency’s Feb. 1 budget request, which is subject to congressional approval, calls for $7.5 million to examine greenhouse gas regulations that may include “market-oriented mechanisms.”..
Jackson said she believes Congress will pass cap-and-trade legislation “hopefully sooner rather than later.”
http://www.businessweek.com/news/2010-03-08/epa-has-no-plans-for-own-carbon-trading-program-jackson-says.html
George E. Smith (15:43:41) :
crucilandia (15:28:30) :
I suspect they are confusing Arctic and Antarctic. Feb Antarctic sea ice shows a 30 year increasing trend of 3.1% +/-4.6 per decade:
http://nsidc.org/data/seaice_index/images/s_plot_hires.png
For Jun it is increasing at 1.1% per decade:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/Jun/S_06_plot.png
For the Arctic in Feb -2.9% per decade
http://nsidc.org/data/seaice_index/images/n_plot_hires.png
This shows the current value at the 4th lowest.
What is most interesting is the trends in the increasing Antarctic sea ice in different months (% per decade):
Jan 2.3
Feb 3.1
Mar 4.7
Apr 3.0
May 2.1
Jun 1.1
Jul .8
Aug .4
Sep .7
Oct .8
Nov .5
Dec 1.1
Based on these figures from NSIDC (links above), the IPCC’s claim of an overall 0.7 ± 0.2% per decade would seem to be in error !