Guest Post by Willis Eschenbach
Inspired by this thread over at Bishop Hill’s excellent blog, I thought I’d write about sea ice. Among the many catastrophic things claimed to be the result of “global warming”, declining sea ice is one of the most popular. We see scary graphics of this all the time, things that look like this:
FIgure 1. Terrifying computer projections showing that we may not have any Arctic sea ice before the end of this century. Clearly, the implication is that we should be very concerned … SOURCE
Now, what’s wrong with this picture?
The problem with the picture is that the earth has two poles. And for reasons which are not well understood, when one pole warms, the other pole cools.
Looking at just the Arctic sea ice is like looking at someone who is pouring water from one glass to another and back again. If we want to see how much water there is, it is useless to observe just one of the person’s hands. We need to look at both hands to see what is happening with the water.
Similarly, to see what is happening in the frozen parts of the ocean, we need to look at global sea ice. There are several records of the area of sea ice. One is the Reynolds Optimally Interpolated dataset (Reynolds OI V2). A second is the National Snow and Ice Data Center (NSIDC) record. Finally, we have the Hadcrut Ice and Sea Surface Temperature dataset (HadISST1). All of them are available from that most marvellous resource, the KNMI data portal .
It turns out that the NSIDC and the HadISST1 records are nearly identical. The correlation between the two in the Arctic is 0.995 (1.0 is perfect agreement), and in the Antarctic it is 0.999. So in Fig. 2, I have not shown the NSIDC dataset, but you can imagine that there is a third record almost identical to the HadISST1 dataset. Here is what has happened to the global sea ice area from 1982 to the present:
FIgure 2. Global Sea Ice Area 1982-present. Data from satellite observations.
As you can see, while it is certainly true that the Arctic has been losing ice, the Antarctic has been gaining ice. And the total global sea ice has barely changed at all over the period of the record. It goes up a little, it goes down a little, it goes nowhere …
Why should the Antarctic warm when the Arctic cools? The short answer is that we don’t know, although it happens at both short and long time scales. A recent article in Science Magazine Online (subscription required) says:
Eddies and the Seesaw
A series of warm episodes, each lasting several thousand years, occurred in Antarctica between 90,000 and 30,000 years ago. These events correlated with rapid climate oscillations in the Arctic, with Antarctica warming while the Arctic was cooling or already cold. This bipolar seesaw is thought to have been driven by changes in the strength of the deep overturning circulation in the North Atlantic Ocean, but some have questioned how completely that process can account for the fine details of Antarctic warming events.
Keeling and Visbeck offer an explanation that builds upon earlier suggestions that include the effects of shallow-water processes as well as deep ones. They suggest that changes in the surface salinity gradient across the Antarctic Circumpolar Current were caused by the melting of icebergs discharged from the Arctic, which allowed increased heat transport to Antarctica by ocean eddies. This mechanism produces Antarctic warming of the magnitude observed in ice core records.
However, not everyone agrees that this is the full explanation. Henrik Svensmark adds another factor to what may be happening:
The cosmic-ray and cloud-forcing hypothesis therefore predicts that temperature changes in Antarctica should be opposite in sign to changes in temperature in the rest of the world. This is exactly what is observed, in a well-known phenomenon that some geophysicists have called the polar see-saw, but for which “the Antarctic climate anomaly” seems a better name (Svensmark 2007).
To account for evidence spanning many thousands of years from drilling sites in Antarctica and Greenland, which show many episodes of climate change going in opposite directions, ad hoc hypotheses on offer involve major reorganization of ocean currents. While they might be possible explanations for low-resolution climate records, with error-bars of centuries, they cannot begin to explain the rapid operation of the Antarctic climate anomaly from decade to decade as seen in the 20th century (figure 6). Cloud forcing is by far the most economical explanation of the anomaly on all timescales.
Regardless of why the polar see-saw is happening, it is a real phenomenon. Ignoring it by looking just at the Arctic leads to unwarranted conclusions about what is happening to sea ice on our most amazing planet. We have to look at both hands, we have to include the other side of the ice, to see the full situation. The real answer to what is happening to global sea ice is …
Nothing.
And for reasons which are not well understood, when one pole warms, the other pole cools.
I see no significant correlation for this assertion in the instrumental record.
During glacial changes, both hemispheres warm/cool, even though one hemisphere is receiving more/less insolation.
And the total global sea ice has barely changed at all over the period of the record. It goes up a little, it goes down a little, it goes nowhere …
Arctic sea ice has declined more than Antarctic sea ice has risen. The long-term trend of sea ice in both hemispheres combined is downward.
http://nsidc.org/sotc/images/arc_antarc_1979_2009.gif
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
A linear plot should confirm this.
But they both have different dynamics, so I don’t know how they can be so simply compared in the first place. Pointing out Antarctic sea ice increase doesn’t say much about projections of Arctic sea ice or the observed decline in that region.
nofreewind (19:31:45) :
“Soon it will be called Arctic Ice Change.”
LOL.
Hello Dr. Svalgaard. Have been reading this month’s Discover, and was intrigued by the article on ultrahigh-energy cosmic rays. Somehow these rays are supposed to be counter to Einstien’s theory of relativity. Yet they don’t really explain why. Would you be able to enlighten me on this?
Thanx.
Leif Svalgaard (21:26:28) :
Harold Ambler (20:27:22) :
But Willis has quoted Svensmark
Perhaps Svensmark works oppositely at the two poles 🙂
You know, when you don’t know how it works, anything is possible…
—
Thank you, Leif! Well-said!
From Willis Eschenbach (21:08:04) :
… it’s not like the world revolves around the Arctic ice area.
No, it rotates around the Earth’s axis, whose North Pole end is about the center of that area. Those two terms do get confused a lot…
*smirk* Sorry about that, Mr. Eschenbach.
It happened before :
http://www.archive.org/details/climatethrouchth033039mbp
CLIMATE
THROUGH THE AGES
A STUDY OF THE CLIMATIC FACTORS
AND THEIR VARIATIONS
By
C. E. P. BROOKS
I.S.O., D.Sc., F.R.Met.Soc.
ERNEST BENN LIMITED
LONDON
Since 1850 winter temperatures have tended to rise
over all the north temperate and Arctic regions and probably
in corresponding latitudes of the Southern Hemisphere.*
The change was slow and irregular at first, but became very
rapid after 1900. The rise in the mean temperature of the
three winter months, from 1851-1900 to 1901-1930, amounted
to 5 F. or more in Western and Central Europe. This
change was associated with a marked strengthening of the
atmospheric circulation and steady west-south-west winds in
Western Europe. There was little change of summer temperature.
Glaciers and ice-sheets receded very rapidly, and
after 1918 little or no drift ice reached the shores of Iceland.
The rise of winter temperature progressed from south to
north, and Central Europe may have passed the crest as early
as 1920 when the rise in the Arctic was in full swing. The
magnitude of the change in the Arctic is shown by the mean
winter temperatures of Spitsbergen, which rose by 16 F.
between 1911-1920 and 1931-1935. The edge of the main area
of Arctic ice also receded towards the pole by some hundreds
of miles. Since January 1940 the winter climate of Europe
has reverted abruptly to greater severity, but it is too soon
to say whether this is the beginning of another long period of
continental climate or only a temporary fluctuation.
and
http://www.archive.org/details/climategreatbri00willgoog
Climate of Great Britain: Or, Remarks on the Change it Has Undergone, Particularly Within The Last Fifty Years (1806)
By John Williams
“In the early periods of our history the isle of Ely was expressly denominated as the Isle of Vine by the Normans.” (The Isle of Ely is an historic region around the city of Ely now in Cambridgeshire, England but previously an island and a county in its own right).
Any chance we could see this same graph with 2008 and 2009 data?
Where does the pre satelite data come from? I know the Cryosphere site shows a chart with pre satelite data that looks suspicious, given that the sea ice area stays extremely consistent for long period of time. Probably from tree rings, huh? Kind of a reverse hockey stick!
jorgekafkazar (22:17:19) :
And we stop building cities below sea level.
Prudent action would be to take the IPCC-projected sea level rise into account, just in case the worst-case warming occurs.
I hear the Himalayans will soon be ice free. Lovely views from up there.
Willis Eschenbach (21:15:02) :
The measurements of Earth’s climate keep getting better and better, but every new satellite or ocean buoy system starts a new dataset, so “long-term” is going to take awhile.
In the meantime, here is ICESat measurements of winter multi-year ice cover in the Arctic Ocean between 2004 and 2008, along with the corresponding downward trend in overall winter sea ice volume, and switch in dominant ice type from multi-year ice to first-year ice:
http://www.nasa.gov/images/content/365871main_earth3-20090707-full.jpg
Why is ice thickness important ?
http://blogs.cars.com/.a/6a00d83451b3c669e20120a7b77994970b-800wi
Thinner ice is more vulnerable to summer warming. As the thinnest ice melts, larger expanses of darker sea water are exposed. These absorb more sunlight than the ice and cause the water to heat up more quickly, thereby melting more ice.
Barber said the ice was now being melted both by rays from the sun as well as from below by the warmer water.
Scientists are also seeing more cyclones, which pick up force as they absorb heat from the warmer water. The cyclones help generate waves that break up ice sheets and also dump large amounts of snow, which has an insulating effect and prevents the ice sheets from thickening.
After a long search, Barber’s ice breaker finally found a 16-km (10-mile) wide floe of multiyear ice that was around 6 to 8 meters (20-26 feet) thick. But as the crew watched, the floe was hit by a series of waves, and disintegrated in five minutes.
http://www.reuters.com/article/idUSTRE59S3LT20091029?sp=true
Unstable, “rotten” ice that looks to the satellites like stable, multiyear ice has been found by in situ visits to these “multiyear ice” regions:
http://www.agu.org/pubs/crossref/2009/2009GL041434.shtml
I wouldn’t depend on the “seesaw” lasting much longer:
http://yankeesabroad.com/wp-content/uploads/2008/07/broken-seesaw1.jpg
Bob Tisdale (18:37:43)
I have averaged the two data sets you provided for the north and south regions.
There is a rising trend in the average data of about 0.4 degrees per 100 years, which is very roughly comparable with the trend in the NCDC land and ocean monthly series from 1880.
As these are anomolies, I am not sure about the absolute temperatures, but I would expect that these would remain well below zero celsius and would not explain the almost 50% ice lost up north since 1960 as shown in chart 1.
From my recollection of other data, there has not been a significant net ice loss in recent years (vague statement) and that the very low northern figure was due to changing wind patters in 2007.
[Ice cover is not “my thing” so I don’t intend to follow this further].
I just end by repeating my earlier point, that reporting alarming changes in one part of a system while ignoring countervaling changes in another is not very helpful. That is why Willis was critising the original chart.
I was not having a go at you.
K-Bob (23:06:21) :
Any chance we could see this same graph with 2008 and 2009 data?
Where does the pre satelite data come from? I know the Cryosphere site shows a chart with pre satelite data that looks suspicious, given that the sea ice area stays extremely consistent for long period of time. Probably from tree rings, huh? Kind of a reverse hockey stick!
Pics Gary Powers took? The USA and the USSR had a lot of planes in the air with good cameras on board for years before satellites went up with publicly known cameras.
Just The Facts (22:02:26) :
Might as well breath normally until October – that’s when they determine if a new record summer melt has occurred:
http://nsidc.org/data/seaice_index/images/daily_images/N_year_timeseries.png
And you might as well get used to waiting – the Arctic probably won’t be ice free in the summer for another decade:
http://news.bbc.co.uk/2/hi/science/nature/8047862.stm
At the same time, Peter Wadhams, head of the polar ocean physics group at the University of Cambridge has brought forward his estimate for the demise of summer sea-ice in the Arctic. He believes the ice, which has been a permanent feature for at least 100,000 years, is now so thin that almost all of it will disappear in about a decade.
He says it will become seasonal, forming only during the winter. He told the BBC: “By 2013, we will see a much smaller area in summertime than now; and certainly by about 2020, I can imagine that only one area will remain in summer.”
Although this bleak forecast is reinforced by the survey team’s data, Professor Wadham’s new assessment is based on analysis of nearly 40 years of sonar data gathered on Royal Navy submarines patrolling beneath the ice – the first, HMS Dreadnought, was in 1971.
Now Professor Wadhams, who has studied the Arctic for the past 40 years, says that there is “almost a breakdown” in the ice-cover.
Over most of the Arctic, there has been a massive decline in the amount of so-called multi-year ice – ice that is tough enough to withstand the summer warmth. Much of what is left of this ice accumulates in an area north of Greenland and Ellesmere Island in Canada, and may form what he calls “a last holdout, a kind of Alamo”.
Professor Wadhams said: “The change is happening so fast. It’s the result of this steady thinning over four decades that has brought it to a state where its summer melt is causing it to disappear.
“It’s like the Arctic is covered with an egg shell and the egg shell has been thinning to the point where it is now just cracking completely.”
It seems to me that this is another example of what is wrong with the climate debate. Probably the assumption that says the weather is chaotic but the climate is not is fundamentally flawed. Cloud formation, volcanic activity, ocean current oscillation, changes in water salinity and a number of other factors- we don’t even know about- influencing the climate are clearly not linear.
Maybe because of my ignorance, but I have always had a hard time understanding how come that the average of a finite number of chaotic processes somehow becomes not chaotic. Could somebody explain this to me?
@ur momisugly Anu (23:19:11) :
Rotten ice. It could equally recover faster than open water, yes?
There is another very simple measurement of sea ice: ocean rise on a selected, stable platform. While the trend over the last 12,000 years, with notable exceptions has been a rise, it is now measurably less than the previous century, leading one to believe the interior Antarctic/Alaska/Canada/ Greenland ice accumulation, should be examined closely. A 20% drop in the rate of water expansion may forebode a cooling period. Such periods are very uncomfortable, although likely temporary. BTW, the nest Ice age is but 3,000 years away. We should enjoy the remaining warmth.
K-Bob (23:06:21) :
Where does the pre satelite data come from? I know the Cryosphere site shows a chart with pre satelite data that looks suspicious, given that the sea ice area stays extremely consistent for long period of time.
———–
I also wonder. One source where that data must NOT come from is reports like this from the 1920s:
“The Arctic Ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot […] Reports from fishermen, seal hunters and explorers all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone …” etc.
–Monthly Weather Review, November 1922 (quoted in the Washington Post on November 2, 1922)
http://tinyurl.com/57jz95
http://tinyurl.com/ylndh9j
pat (21:35:32)
I think you misunderstand me. I am against the vain attempt to restrict CO2. I think that the change in CO2 from 0.03% to 0.04% or even 0.05% of the atmosphere will make no detectable difference in the global temperature.
Arctic ice cap is showing toughness and fortitude on the charts. Desperate times for Phil Jones & Co. Deep in the bowels of CRU, a plot is hatched: get the government to re-assign 007 (James Bond) to hijack the Russian space lens and point it at the Arctic ice cap to hurry up the melting!
barry:
It’s clearly there in the annual record. Of course that’s a no brainer (tilt in the Earth’s axis). I don’t think there is any evidence for it in multiyear fluctuations though.
They seem to synchronize at times, but that appears coincidental to me.
Steve Goddard (21:54:36)
Well, lets see. When one goes up the other goes down … so if you subtract one from the other, why on earth would you expect the slope to be zero unless you have gone through at least one complete cycle?
And since the last warm period in the Arctic was in the 1930s, that suggests that the cycle is on the order of 80 years … I’m sure you see the problem with your claim.
jorgekafkazar (22:17:19)
Don’t tell the Dutch …
Leif Svalgaard (21:53:49) :
Actually, it would put him in his 70s. The pole moves 50.3 seconds of arc a year and a degree every 71.6 years. “Very old” is a relative thing.
barry (22:34:05)
But they both have different dynamics, so I don’t know how they can be so simply compared in the first place. Pointing out Antarctic sea ice increase doesn’t say much about projections of Arctic sea ice or the observed decline in that region.
Anti-persistence is a problematic problem for the proprietors of AGW models.eg Carvalho et al 2007.
Anti-persistence in the global temperature anomaly field
Abstract. In this study, low-frequency variations in temperature
anomaly are investigated by mapping temperature
anomaly records onto random walks. We show evidence that
global overturns in trends of temperature anomalies occur on
decadal time-scales as part of the natural variability of the climate
system. Paleoclimatic summer records in Europe and
New-Zealand provide further support for these findings as
they indicate that anti-persistence of temperature anomalies
on decadal time-scale have occurred in the last 226 yrs. Atmospheric
processes in the subtropics and mid-latitudes of
the SH and interactions with the Southern Oceans seem to
play an important role to moderate global variations of temperature
on decadal time-scales.
A significant constraint on the conjecture of a monotonic warming global signature.
Conclusions
The anti-persistence of the temperature field on inter-decadal
time scales is part of the decadal variability of the climate
system and this property has not been identified before. Processes
at time scales longer than that of ENSO are also
responsible for maintaining stationarity in the temperature
anomaly field. In addition, our results indicate the importance
of the Southern Oceans in regulating temperature fluctuation
regimes on long time-scales. The origin of interdecadal
fluctuations in the climate system is currently one
of the most challenging problems in climate dynamics
O.T.
Question,
Is it fair to measure average Atmospheric CO2 levels at the site of a Volcano thats been active since 1984?
Willis, I see that the graph in the post comes from the Bjerknes Centre in Norway. They are 100% IPCC loyalists.
Mr. Drangedal from this centre has volountered as lead author for the next round. He is the one that was in the newspapers in Norway a couple of weeks ago, asking all cities in Norway to make crisis plans against flooding.
So dont expect a better IPCC.
The Bjerknes Centre is FEEDING on AGW-alarmism.
Thats what gives them bread on the table.