Global Sea Ice Trend Since 1979 – surprising

Much importance has been ascribed to tracking the change in Arctic sea ice, but what about the global trend? That doesn’t seem to get much press. However there is some important information that needs to be presented related to the global trend of sea ice as measured by satellite since 1979. The results are surprising. – Anthony

global-sea-ice-from-aqua

Source: NASA’s Aqua satellite – click for larger image


A guest post by Jeff Id, from The Air Vent

2nd Update 12/24/08  It turns out that an error in documentation at NSIDC is the cause, see this new post for a full explanation.

Update and correction:

To my readers, Anthony Watts received a comment from our friend Tamino on the ice data I used for the area analysis. Unfortunately for me he is right this time. It appears that a correction to the data is required prior to 1987 which will create an approximate negative trend of 0.88 million sq kilometers per 30 years. It is a fairly small trend in the scheme of a 20million sq kilometer signal, but understand this mistake is entirely mine and is unrelated to Anthony Watts excellent blog.

Unfortunately the change makes the Area signal difficult to determine prior to 1988 because the percent fill is unknown. Anthony cannot check every detail of a post which took me days of research and he simply requested if he could copy it here.

The link to my corrections is:

http://noconsensus.wordpress.com/2008/12/16/sea-ice-decreases-despite-the-air-vent/

My apologies.

Jeff Id


I calculated a true global sea ice anomaly in this post using the National Snow Ice Data Center data. What would you say if I told you that over the last 30 years the sea ice area has stayed flat or even trended — Up!!!???

This isn’t a small deal. We have been told, well screamed at really, that CO2 is causing unprecedented rise of temperature on a global scale. We hear constantly that the ice is melting and the result will be dramatic flooding of the earth; movies have even been made. Those of us who pay attention to the scientists have heard that the most significant warming will be at the poles (according to the computer models). We also hear that the Antarctic has added ice during the same time the Arctic lost sea ice. This is explained in that the Antarctic ice increase is a local situation and the Arctic ice loss is a result of global warming. A unique form of cherry picking but should be treated with an open mind.

If you’ve been paying attention, you have heard that the net ice level is going down. The Antarctic gain cannot compensate for the Arctic loss. Well, I set out to see how bad the situation is.

First, anthropogenic global warming scientists use two measures, extent and area.

Extent looks at all the square Kilometers (Km^2) with more than 15% ice in them and adds them up.

Area looks at all the square Kilometers (Km^2) with more than 15% ice in them and adds them up but multiplies the Km^2 by the amount of ice in the square kilometer. i.e -(if you have 1 Km^2 of sea filled 15%, ice- extent counts it as 1Km^2 while area counts it as 15% of 1Km^2 or 0.15Km^2)

This post deals with the amount of sea ice so I used Area. In the future Iwill do it with extent. The NSIDC uses two algorithms for calculation of sea ice, nasateam and bootstrap. We will look at both here.

Without modification the NSIDC data for bootstrap runs from 1978-Dec. 2006 and the nasateam runs from 1978-Dec 2007, these near 30 year trends comply close enough with current science which states (conveniently) that climate requires a 30 year trend to see the result.

This is a graph of the global sea ice area from the nasateam algorithm.

global-sea-ice-nasateam-algorithm-area

The red line is the slope of the global sea ice data from nasateam in its raw format. The slope is negative by only 6803 Km^2/year and the mean is 18,290,000 km^2.

We should look at sea ice anomaly to be the most accurate for trend. To calculate sea ice anomaly I took the average shape of the annual signal and subtracted it from the curve above.

The average ice variation globally looks like this on an annual basis.

global-30-year-average-nasateam-algorithm-area

I subtracted this curve above to get the sea ice anomaly.

global-sea-ice-area-anomaly-nasateam-algorithm2

The downward slope of this graph is more extreme but the scale is highly magnified. The net downslope in 30 years of global warming is – 10173Km^2/year. Over 29 years of data this means that we have lost 302025 Km^2 of ice. This is a 1.65 percent drop in global ice level in 30 years. Remember though that this data ended on an extraordinary high melt year of 2007, the ice level can be seen recovering in dec 07 leading into 2008. This shows as a slight change in slope of the very tip of the first graph (a subtle, difficult to see effect).

Well NSIDC recommends using the Bootstrap algorithm for research instead of Nasateam because of certain errors which have been corrected for.

The bootstrap algorithm plot for global data looks like this.

global-sea-ice-area-bootstrap-algorithm

The red line is slope again, and this time it is positive, indicating an increase in ice level from 1978-Dec 2006. The slope of the red line is plus 6341 km^2 per year indicating that the earth in 28 years has added 177,000 sq kilometers of ice with a mean ice level of 20.42 million Km^2.

The anomaly is better for calculating trends because it cleans up the end points making the slope insensitive to the start and stop point of the annual cycle.

global-sea-ice-area-anomaly-bootstrap-algorithm

The up trend for the anomaly in sea ice from 1978 to end 2006 is 804Km^2 per year. Which in our timeframe the preferred bootstrap algorithm says the earth ADDED 22,000 Km^2 of ice area!!

Here are the anomalies rescaled to actual by adding the mean of the original data back in.

global-sea-ice-area-variation-nasateam-algorithm

global-sea-ice-area-variation-bootstrap-algorithm1

Obviously people cannot make the claim that sea ice is being lost. It isn’t. The data shows that our trend is basically flat during this time of unprecedented temperatures. It’s clear that there has been no significant change in sea ice area.

This is almost enough to make me turn in my Skeptic union card, but increased CO2 warming the earth makes some sense to me, the magnitude is in question. The fact that polar sea ice not melting is not an insignificant point. It is also important to realize that the changes are too small to fit with IPCC statements about the trend. Unlike trees, ice does make a good thermometer. I can’t say this strongly enough— This is a strong indication of substantial errors in the computer models and temperature data which needs to be addressed before we throw what’s left of our global economy to the wind. How would Earth’s total sea ice ignore such substantial warming? It’s a good question which deserves an answer.

I will update this when new data becomes available and will also attempt to demonstrate that the net slopes we see are within the margin of error for the measurement in a future post. In the meantime, lets let the world know the truth. We aren’t going to drown any time soon!

————————

I had a request for description of the difference between the bootstrap and nasateam algorithms. It is a bit complex but it seems well documented on the NSIDC here are a few links and descriptions from that site. From FAQ section.

2. What is the difference between the NASA Team algorithm and the Bootstrap algorithm?

For general analyses or creation of simple images, either algorithm will suffice. The Bootstrap sea ice concentration data set is believed to be more useful for modeling and process studies in the polar regions because it is generally free of residual errors that could not be removed by conventional techniques. A temporally more consistent time series of sea ice concentrations is provided, offering improved accuracy over the ice concentration maps created from the original Bootstrap algorithm.

More interesting to me was the table provided which shows the strenghts and weaknesses of each process. The original table is at the link above.

bootstrap-vs-nasateam-table

For more details and complete descriptions NSIDC provides two links Bootstrap and Nasateam

HERE is a link to the R code to make the above graphs.

Data sources:

ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/


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David Ball

An area of ice the size of the United States melts and re-freezes each year. This is an important article. Thank you Jeff

The raw theory that increasing CO2 will “show up” at the poles makes sense: The AGW extremists know that at the poles the air is both extremely cold AND extremely dry (on average) so CO2 (at the same percentage as in warmer, more humid areas (ie, the rest of the planet!) makes up a significantly greater amount of the total greenhouse gasses present.
If CO2 increases, then (reasonably) there will be a significantly greater percentage increase in greenhouse gasses at the poles than in the rest of the plant.
Therefore, since (in their minds) CO2 is the great evil, and since there are no other GHG than Co2, the poles MUST melt first. So, every thought in their minds since Hansen’s 1988 presentation to Congress has focused on the “proving” that the poles will melt. (And then kill us all.)
[Notice how the common Mercator projection in every classroom that exaggerates Greenland’s area helps this fear: When Greenland is projected as nearly twice the size as Australia, and when Greenland is displayed as about the same size as Brazil or Africa, then (when) that “huge area” melts, obviously the earth “must get” catastrophically flooded … And the politicians play on this fear – as Gore so recently did.
——
Notice too that even ONE YEAR of “normal ice re-freezing throws out every real piece of the scare tactics: The ice that must melt in say 2010 is what was left over from 2009 into 2010. What was melted in summer 2007 (and then re-froze in winter 2008-2009) doesn’t matter at the edges of the ice pack.
True a long-term trend would matter – But from these graphs there is no long-term trend of costantly melting ice.

Yet the politicans, and their budget-linked members of the “science” community don’t care.
Fear sells.
Truth shows previous lies as the lies that they are.

helvio

So, even with the big melt in 2007, we still see an average increase in sea ice anomaly trend with bootstrap. In that case, if you ignore the 2007 data (just for the fun of it) I bet we would see a much greater slope upwards in the 30-year trend. 2007 looks like an anomalous year, which may be influencing the statistics too much and masking a more realistic climatic trend. Just like the 1998 El Nino temperature-anomaly spike doesn’t seem to help the calculation of its long term trend, but only to increase its statistical fluctuations.

KBK

This compares well with the global sea ice graph from

KBK
Graeme Rodaughan

I’m shocked – that poor fellow Pugh paddled all the way to the north pole for nothing…

Graeme Rodaughan

Is it possible to get this work into a “Peer Reviewed” journal?

Graeme Rodaughan

Excellent work Jeff.

Graeme Rodaughan

It also begs the question – of why hasn’t NSIDC noticed this and published these results?

Filipe

I’m puzzled, why the 15% rule for the area? Why not adding everything?
In computing extent I understand the need for a cut-off like this, but even then an indication should be added with the size of the regions with let’s say 15% +- errors from instrument sensitivity. I’d like to have an idea of the biases that come from simple truncation.

Mark

I hope this analysis is right…

An interesting check to my results is at this link.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
The university of Illinois is using a slightly different dataset. I wrote for the data but haven’t received a reply. You can see from the graph that the shape of the curves I calculated is accurate. UIUC data has a ‘slightly’ stronger negative slope for some reason.

Leon Brozyna

A really inconvenient truth — it seems that total polar sea ice is essentially stable, notwithstanding Mr. Gore’s panic attack prediction.

Tim L

The truth is full of (strike(good news) bad news.
I see a 3-4 year downward trend (2003-2007) also it appears we are starting into an upward trend. the agw crowd will cherry pick this as “proof” of ice loss. I see the beginnings of a cold trend as the Antarctic remains frozen and the arctic begins to freeze up more. less food can grow in the cold. longer winters. more clouds.
what would be interesting would be to subtract the two variations ( bottom two grafts) and see the error ( noise ). because that is what they (agw promoters use) to twist the data around.
Good job Jeff

Phil

RE: David Ball (19:11:49):

Anthony: How come we don’t drown via sea level rise each Arctic summer (assuming Antarctica doesn’t freeze as much ice as melts in the Arctic)? Is it because most of the ice that melts in the Arctic is floating ice?

REPLY: Yes, try the ice cubes in a glass filled to nearly the top with water experiment. They float, they melt, but the glass does not overflow.
Greenland ice is an entirely different issue, since it is land bound. – Anthony

evanjones

Yes.

Jeff Id,
May I ask some questions concerning the difference of the two methods.
The nasateam data extend closer to present day than the bootstrap data. Does nasateam use a running mean taken over previous data, while bootstrap uses a mean including forward data as well?
When looking at the two anomaly curves, they show a similar peak structure. But subtracting the two curves will not generate white noise?
Maybe, when you put in a certain time shift between the two curves?

phoynix

I love how you say cherry prick, you take only sat photos, completely ignore all other data such actual physical investigations of the caps.
Studies which have physicly found that the Perma-ice has lower denisity and is now honeycombed with airpockets.
If you can provide me with data that shows that hundred of thousands of years old ice which used to be known as completely solid but which has now lost a good majority of its internal volume is normal.. or the data is all made up.
I might actually believe our planet isnt as screwed up as they say.

sven

What’s this? Has the arctic ice been melting?! In december?!
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

Lamont

The northern hemisphere has more people, more CO2 emissions, and more water to moderate the effects of AGW. The Antarctic and the southern hemisphere was predicted to lag behind the northern hemisphere in its response to AGW:
http://www.realclimate.org/index.php/archives/2008/02/antarctica-is-cold/langswitch_lang/sw#more-529

Scott Gibson

The shape of the 30 year average sea ice area is also very interesting. Assuming that the Day of Year axis represents a normal western calender, the areal extent of sea ice seems to fall to a minimum during the Antarctic summer, with a much smaller dip during the Arctic summer. That suggests that there is a lot more sea ice around the perimeter of Antarctica than in the Arctic region, contrary to my expectations.

Exotic Electron

Area does not equal mass. Very deceptive data mining.

Lamont: SST for the Southern Ocean stopped its rise more than 20 years ago and has been on a sharp decline for more than 10 years.
http://i35.tinypic.com/s3djds.jpg
With respect to your realclimate link, they searched and found a few reports that discussed very specific climate models of the Antarctic and the Southern Ocean to illustrate that “A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.”
But what do other models say? Look at the two graphics of GISS equilibrium runs used by realclimate in another discussion, the first two figures in the following.
http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends
There is NO cooling in the lower troposphere of the Antarctic in either illustration. While the high latitudes in the Southern Hemisphere do not warm as greatly as they do in the North, they still show warming,
Climate models contradict one another, so some will be consistent with reality while others will not. What value do they have then?

Dodgy Geezer

@phoynix
“Studies which have physicly found that the Perma-ice has lower denisity and is now honeycombed with airpockets.”
Can you give us a reference to any of these?
“If you can provide me with data that shows that hundred of thousands of years old ice which used to be known as completely solid but which has now lost a good majority of its internal volume is normal.. or the data is all made up.”
Not sure what this means, but if you are looking for data on ice mass then I know that there are gravity-based estimates of ice mass, which would automatically correct for cavities in the ice.
“I might actually believe our planet isnt as screwed up as they say…”
I don’t think ANY planet can be a screwed up as ‘they’ say…..

Lamont: You wrote, “The northern hemisphere has more people, more CO2 emissions, and more water to moderate the effects of AGW.”
First, CO2 is a “well-mixed greenhouse gas”, so that part of your statement has little substance. Second, oceans cover approximately 60% of the Northern Hemisphere, and for the Southern, they cover about 80%, so that part of your statement is wrong.

old construction worker

Lamont (00:08:06)
‘The northern hemisphere has more people, more CO2 emissions, and more water to moderate the effects of AGW. The Antarctic and the southern hemisphere was predicted to lag behind the northern hemisphere in its response to AGW:’
Your statment, like the co2 theory, doesn’t make sense. …to moderate?
And all this time I thought co2 was ‘well mixed’ in the upper troposphere.

The trouble is it has always changed and always will especially with a live volcanoe under the ice ,If you look at history it clearly shows everytime the c02 is high the earth has been cooler not warmer ,the tree rings show that c02 in high amounts make eveything grow 75%faster ,at the end of the day no one can predict in 100yrs or conttrol it ,that is impossible ,this is a scam thats why there is no quantified equasion to predict anything exisists because its impossible .Ethanol reduces c02 slightly but burns with a lot more polluting solids as found by testing recently ,it also clogs motors and catalyic converters and produces nitros oxide which is a lot worse and that is smog ,more lies ,c02 is essential for every living thing on the planet not a pollutant .

Carlo

And the Arctic ice thickness?

Perry Debell

Lamont,
Do I understand you to be suggesting that the increasing ice around the Antarctic is because the alleged AGW has not yet caused the ice to melt, but that I must believe you when you say it will melt, eventually?
You also state that more people, more CO2 emissions, and more water moderate the effects of AGW. What do you mean by “moderate”? Do you mean to “lessen” the effects of AGW, so that the Arctic ice will increase or do you mean “potentiate” the effects of AGW, so that the Arctic ice reduces?
I am directed to point out that the Arctic and Antarctic ice is increasing in both extent and area.

Robinson

Is anyone losing the will to live?
I’m not a conspiracy theorist, but I’m starting to wonder how so many smart people can be so stupid for so long. When I hear a politician putting `Climate Change’ in his top three problems that need to be solved and then browse either here or Steve McIntyre’s website, I’m literally gob-smacked at the unbelievable stupidity of the whole warming thing.
Do we sceptics all think about this problem with a different region of the brain to the warmists? The fallacy of CO2 based anthropogenic global warming is so self-evident, I’m wondering if such a difference in perceptual capabilities might explain it. Either that or the policy based evidence making is just that: we must stop sending trillions of dollars out of our economies to pay for oil and gas and here’s a good way to move people away from it.
Either way my (and public) trust in science is set to take a nose-dive. It’s a profoundly depressing situation.

Spathirin

Could someone explain why thickness/mass is important?

komkondor

“If you look at history it clearly shows everytime the c02 is high the earth has been cooler not warmer ,the tree rings show that c02 in high amounts make eveything grow 75% faster”
Look that, please:
“Abstract
The writers investigated the effect of CO2 emission on the temperature of atmosphere. Computations based on the adiabatic theory of greenhouse effect show that increasing CO2 concentration in the atmosphere results in cooling rather than warming of the Earth’s atmosphere.”
In Cooling of Atmosphere Due to CO2 Emission, by Authors: G. V. Chilingar; L. F. Khilyuk; O. G. Sorokhtin.
http://www.informaworld.com/smpp/content~content=a788582859~db=all

phoynix,
“I love how you say cherry prick, you take only sat photos, completely ignore all other data such actual physical investigations of the caps.”
There has been no selection of one data set over another. I used this data because it had a long timespan, it was well documented and was available.
I separated the NH and SH out in previous posts. Some here have already seen them but I think they show a lack of selective plotting.
NH
http://noconsensus.wordpress.com/2008/12/13/sea-ice-area-or-anomaly/
SH
http://noconsensus.wordpress.com/2008/12/14/sh-sea-ice-data-and-anomaly/
Lamont,
I think others have already addressed your points (thanks to Bob T and the Geezer) but on the Air Vent it is my policy to not accept real climate references as valid.
Consider that they will not accept dissenting opinion and also consider that they not only accept but embrace the Mann papers. Papers which are so mathematically and data flawed that you couldn’t push them through an undergrad stats class. They are well informed so you can learn things from them but they ceased to be scientists long ago.

Werner Weber,
“Does nasateam use a running mean taken over previous data, while bootstrap uses a mean including forward data as well?”
It’s a good question, I don’t think this is being done but I don’t know. I just assumed the government was a bit slow in updating the web. There are some verification processes involved in releasing the data which may have something to do with it. I will look into it more over the coming weeks.
Subtracting these curves will show a difference in method but since the data came from the same sensors I don’t know what we would learn.

Exotic Electron (01:09:51) :

Area does not equal mass. Very deceptive data mining.

Area is easier to measure than volume. At the beginning of 2008’s melt season, official ice watchers pointed out that while ice area recovered well during the winter, there was so much thin first year ice that the melt would proceed quickly and there would be more melting than in 2007.
We wound up with 9% more ice at the low point than in 2007 – evidence that supports an injection of warm water into the Arctic Basin had melted ice from below and that the 2007 melt was anomalous.
Except for the warm water event, any discussion about the 2007 melt and its aftermath may be very deceptive data mining.
What’s the difference between an exotic electron and a boring one? Is one really a positron or muon?

Chris Wright

Graeme Rodaughan (19:55:36) :
“I’m shocked – that poor fellow Pugh paddled all the way to the north pole for nothing…”
He actually gave up hundreds of miles short of the pole. The reason? Too much ice. And too much cold.

We need to be careful focussing upon ‘trends’ – it can lead to serious errors of context – and this underlies the entire ‘global warming’ thesis which relies upon computer models with entirely false (i.e. non-natural) notions of an equilibrium starting point and calculations of trend – this conveniently ignores cycles, and it has to because a) there are several non-orbital cycles in motion (8-10 yr, 11, 22, 60, 70, 80, 400 and 1000-1500) depending on ocean basic, hemisphere and global view – all interacting via ‘teleconnection’ of those ocean basins , some clearly timed by solar cycles, some peaking together; b) because the cycles are not exact, you cannot tell in any one decade where you are in the longer cycles. Thirty years is far too short to encompass a cycle for the Arctic sea ice where the major cycle is at least 70 years – the best cycle context for this I have found is represented in the State of the Arctic Report or the work of Igor Polyarkov at IARC Fairbanks – looking at Surface Air Temperature trends for the whole Arctic – 60-90N, for the century you can see two peaks in 1940 and 2005 with a trough in the mid-80s (if anyone can tell me how to copy in a jpg I could put one in here!).
Thus, whatever is happening now in the Arctic, if it is air-temperature related, then something similar happened then – but instrumental records were different. If you read E. Hanna et al in the Arctic Report Card 2007 (www.arctic-noaa.gov/reportcard/ArcticReportCard_full_report.pdf):
“Over the past century, years in Greenland that register as abnormally warm, 1929, 1932, 1941, 1947, and 1960 are outstanding, having temperatures warmer than observed recently. Increases in GrIS melt and runoff during this past century warm period must have been significant and were probably even larger than that of the most recent last decade (1995-2006).”
However, despite this, the team reckon to have perhaps isolated a ‘global warming’ signal in the accelerated run off of the Greenland Ice Mass – but only just, because the runoff at the edges is balanced by increasing central mass – again, they focus upon recent trends – a net loss of about 22 cubic kilometres in total ice mass per year which they regard as statistically not significant – to find the ‘signal’, and a contradiction to their ealier context of air temperature cycles.
Anyone reading the Report Card can choose to focus upon the recent ‘trend’ and call it global warming, or the 70 year cycle.
Even if the recent cycle (of which there is evidence of a turning through 2006-2008 with run-off slowing in Greenland and the 2008 summer sea-ice melt 9% up on 2007), is different from the previous in terms of the overall pattern – as some argue, this can just as easily be the effect of the 400 year cycle – recovery from the Little Ice Age, upon which the current 70 year cycle piggbacks. See the essay by recently retired director of the International Arctic Research Centre – Dr Syun-Ichi Akasofu (www.people.iarc.uaf.edu/~sakasofu/pdf/recovery_little_ice_age.pdf). So then, given that we are at a peak of the 400 year cycle and the LIA was a trough, we need to go to the previous peak – 800 years give or take a bit (and remember there is a lower frequency cycle below this one, probably due to ocean overturning) and we are in Viking settlement times on Greenland and legends of the circumnavigating Chinese fleet sailing home via the Arctic Ocean!
For a useful critique of model-starting-points which bear no relation to the real-world, see: D. Koutsoyiannis et al (2008) ‘On the credibility of climate predictions’ in Hydrological Sciences 53(4) August 2008 671-684, who conclude that the GCM models defy normal assessments of validity and should not be relied upon to predict future climate change.
And with regard to Antarctic ‘trends’ – virtually all the action is on the Peninsula region and the Western Ice Sheet (about 15% of the area) – with no significant trend for the other 85% of the continent. And it is known that the southern polar regions ‘see-saws’ with the northern – so when the north polar is on the up cycle – the south polar in on a downer (Bob Tisdale’s graph of the southern ocean SSTs shows this clearly for the ‘global warming’ period of 1980-2005 – and the Peninsula Region just catches a flow-in from warmer seas to the north).

Mark

Re: Lamont (00:08:06)
The same reasoning applies to Ozone yet somehow it seems to have ‘drifted’ mostly to the south pole. I guess the air currents were such that they moved ozone but not CO2?

Boris

“This is a strong indication of substantial errors in the computer models and temperature data which needs to be addressed before we throw what’s left of our global economy to the wind. ”
What errors would these be, then? Have you even looked at what the models say–especially about Southern hemisphere ice extent? How can you make such a bold statement without even consulting the literature?

Pamela Gray

By the way, I know who took the ice from up North. Oregon. The new Arctic.
BRRRRRRRRR!!!!!!!

Rhys Jaggar

The key number is neither extent nor area, but VOLUME.
That is: area*thickness.
I know that thickness has declined significantly in the arctic, but have we had accurate measurement of ice thickness long enough to make any meaningful interpretations?
Particularly in the Antarctic, where this may have a major impact on overall data…….
Look forward to hearing from the pros on this…..

Paul Shanahan

In relation to the questions about ice thickness, I understand why the question is being asked, truly, but I don’t believe it is a relevent question for this topic. I believe this for two reasons;
1) The research is based on ice area, not mass
2) As we are dealing with ice area, it is logical that the primary driver of area will be to do with ocean ice. Given the annual cycle of melting and refreezing for the majority of sea ice, thickness is not relevent as it would dissapear and re-appear annually.
Also, looking at Cryosphere Today, I don’t see a lot of difference in the thickness of the ice, only that it has moved around. (Darker Purple = Thicker)
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=12&fd=01&fy=1979&sm=12&sd=01&sy=2008
Correct me if I’m wrong, it’s only a laymans (mine) thought process…

own

there is a recent article where the geographical distribution of the warming was analyzed in detail
(by Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center (ESSC) at The University of Alabama in Huntsville.)
see e.g. for summary
http://www.physorg.com/news148239677.html
I think it is pretty clear why ice in south will grow as it has been cooling down durint the last 30 years !!

Boris,
You are right that I shouldn’t editorialize without reference, however lack of reference doesn’t imply lack of consultation. I assume that you know these models have been ‘updated’ over the years to show a different result. Most predictions I’ve seen show a net warming at the poles after all it is the antarctic land based ice which will eventually flood the earth.
Rhys Jaggar,
If you can show me a reputable volume data set for both poles I will plot that also. In the meantime ask yourself, how would a substantial change in volume have no effect on area and does the alternative explanation seem likely?

The Diatribe Guy

Mass/Volume only seem to be relevant when someone points out that total area hasn’t declined. When pointed out that, in the Antarctic, there are many places where there is increased ice pack over the last few decades, even if some shelf here or there falls into the ocean, we are told that the mass isn’t as important as the area.
Now, we see that neither mass nor area in the Antarctic has not perished, and area is making a comeback in the north.
This is very inconvenient, so the logical thing to do is tell us that mass in the north is really what’s important.
In my line of work, I end up throwing out models and stats at least as often as I actually use them. It never ceases to amaze me that a simple application of common sense more often than not gets you the right answer.
And common sense says that we have long since passed the point of common sense being applied in the climate change arena. Imagine the good we could actually do if we simply stopped wasting time, energy, and resources on this non-existent problem.

I’m still staring at the AMSR-E sea Ice extent graph, which right on cue with Al Gore’s proclamation that the Artic ice would be gone in five years (so give Al money now!), the line for 2008 began indicating that the Artic ice is decreasing.
right.
Who pays for that graph?

Cathy

@Robinson
“Is anyone losing the will to live?”
OK. Don’t let the bastards ruin what time you have during this fascinating voyage.
Shake your head at their folly. It’s always been so with most of our species.
Then enjoy the mystery, the timeless cycles. The sun (diminished as it is) rising.
Time will throw the necessary light on this silly, misguided foolishness.

Eric

Global Sea Ice as calculated is an irrelevant statistic.
The Antarctic sea ice is one year ice. It melts every year. The winter ice is unimportant to the earth’s albedo because the sun hardly shines on it.
The Antarctic sea ice in winter is increasing, but it doesn’t have any impact on global warming.
The summer ice area is the thing to look at, and it is decreasing in the Arctic and more and more ice is one year ice.
It seems to me that this blog has the effect of diverting attention from the important summer Arctic Sea Ice trend which has gone downward sharply in the past few years.

Rhys Jaggar

Jeff ID
The answer to you question on changein volume vs no change in area (or little change) presumably is that the area won’t change if the ice is 10cm vs 10 metres.
At the very margins, this doesn’t matter, what does matter is where ice is retained all summer but a lot of the top ice melts off, so the area doesn’t change but the volume does.
That’s what I’m thinking. It won’t change at the poles probably, but at the periphary of the permanent ice.
My view is this: it’s easier for scientists to measure area than volume, so they measure area.
I don’t know the reliability of the techniques, but aren’t there guys at UCL in London who’ve used satellites to measure thickness recently?

Fernando

Jeff Id: Good Job….fantastic
Eduardo Ferreyra;
Hudson Bay: game over
http://saf.met.no/p/ice/nh/conc/conc.shtml
Pamela:
NOAA
Niño 3-4…..12/08/2008….-0,5ºC
Niño 3-4…..12/15/2008….-0,7ºC
open count;
NOAA:
“A majority of ENSO forecasts indicate slightly below average SSTs in the central equatorial Pacific through Northern Hemisphere Summer 2009. Several models suggest weak La Niña conditions during December 2008-March 2009.”
FM