Surprise: Peer reviewed study says current Arctic sea ice is more extensive than most of the past 9000 years

While Joe Romm and Mark Serreze bloviate about the current Arctic sea ice being “lowest in history”, science that doesn’t have an agenda (or paying thinktank) attached says otherwise:

More importantly, there have been times when sea-ice cover was less extensive than at the end of the 20th century.”


The satellite sea ice record, only a speck in time

From the Hockey Schtck: Paper: Current Arctic Sea Ice is More Extensive than Most of the past 9000 Years

A peer-reviewed paper published in the Canadian Journal of Earth Sciences finds that Arctic sea ice extent at the end of the 20th century was more extensive than most of the past 9000 years. The paper also finds that Arctic sea ice extent was on a declining trend over the past 9000 years, but recovered beginning sometime over the past 1000 years and has been relatively stable and extensive since.

Although it seems like a day doesn’t go by without an alarmist headline or blog posting obsessing over the daily Arctic sea ice statistics (and never about Antarctic sea ice extent which reached a record high this year), this paleo-climate perspective takes all the wind out of alarmist sails. Satellite assessment of sea ice conditions is only available beginning in 1979 (around the time the global cooling scare ended), with only sparse data available prior to 1979. The alarmists at the NRDC fraudulently claim in a new video that due to “climate destruction,” Arctic sea ice reached the lowest in history in 2010 (actually the low since 1979 was in 2007 and 2010 was the 3rd or 4th lowest depending on the source). Probably wouldn’t bring in many donations if they mentioned the truth: the 21st century has some of the highest annual Arctic sea ice extents over the past 9000 years.

The figure below comes from the paper, but has been modified with the red notations and rotated clockwise. The number of months the sea ice extent is greater than 50% is shown on the y axis. Time is on the x axis starting over 9000 years ago up to the present. Warming periods are shown in gray with the Roman and Medieval warming periods (RWP/MWP) notated, a spike for the Minoan Warming Period about 5000 years ago, and two other older & unnamed warming periods. The last dot on the graph is the end of the 20th century and represents one of the highest annual sea ice extents.

Holocene fluctuations in Arctic sea-ice cover: dinocyst-based reconstructions for the eastern Chukchi Sea Canadian Journal of Earth Sciences, 45: 1377-1397

Authors: J.L. McKay, A. de Vernal, C. Hillaire-Marcel, C. Not, L. Polyak, and D. Darby

Abstract: Cores from site HLY0501-05 on the Alaskan margin in the eastern Chukchi Sea were analyzed for their geochemical (organic carbon, d13Corg, Corg/N, and CaCO3) and palynological (dinocyst, pollen, and spores) content to document oceanographic changes during the Holocene. The chronology of the cores was established from 210Pb dating of near- surface sediments and 14C dating of bivalve shells. The sediments span the last 9000 years, possibly more, but with a gap between the base of the trigger core and top of the piston core. Sedimentation rates are very high (*156 cm/ka), allowing analyses with a decadal to centennial resolution. The data suggest a shift from a dominantly terrigenous to marine input from the early to late Holocene. Dinocyst assemblages are characterized by relatively high concentrations (600–7200 cysts/cm3) and high species diversity, allowing the use of the modern analogue technique for the reconstruction of sea-ice cover, summer temperature, and salinity. Results indicate a decrease in sea-ice cover and a corresponding, albeit much smaller, increase in summer sea-surface temperature over the past 9000 years. Superimposed on these long-term trends are millennial-scale fluctuations characterized by periods of low sea-ice and high sea-surface temperature and salinity that appear quasi-cyclic with a frequency of about one every 2500–3000 years. The results of this study clearly show that sea-ice cover in the western Arctic Ocean has varied throughout the Holocene. More importantly, there have been times when sea-ice cover was less extensive than at the end of the 20th century.

Arctic summer sea surface temperatures are also currently lower than much of the past 9000 years


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As “Interesting Times” goes on, while we eat our pop-corn and comment at WUWT, the real icy issues will begin to take an equally more interesting perspective as your next winter time grows near.
Igloos anyone?


So, our carbon is interfering with nature’s trend towards ice-ball earth?

Thanks to whomever made the paper available.
Present conditions of polar temperature are several degrees below peak levels reached several times during the last million years. We have been in a cooling trend for about 10,000 years, but still remain well above average temperature. (Incidentally, CO2 has been rising through most of this cooling trend).

One more in a long series… History gives us lessons every day!

Danny V

Canucks rock when it comes to reasonable approaches to climate studies.


As some have posted on this site, the “beginning of the end” of the Holocene interglacial might indeed have been about 1-2 kYrs ago.

Ken Hall

This does fit in with the climate record from the end of the last ice age when it was warmer than today.

No wonder, since the last interglacial was warmer than today for most of the time;
Greenland ice core says so:
and instrumental record, which hints the Arctic ice was the same in 40ties
and known events, like NW Passage open for shipping in 1942-44 just like in 2007-2009


This is all beginning to resemble one of those boxing matches where the hot young favourite is first knocked down, gets up groggy, dazed and reeling, and is then repeatedly hammered mercilessly by the old-timer until, staggering and bleeding, he collapses on the ropes. The last few posts on WUWT have been like a count-down to the end of the CAGW scam and we can all hope it’s carried out on a stretcher soon. Can’t you see the faces of the guys in the red corner? Seven, eight ……….
Thank you Anthony and all those others who have been the frontfighters in this struggle for the return of real, honest science.


Considering historical records about sea ice extent in the Arctic, this is not surprising at all. I’m sure, however, that the warmers will take exception to these conclusions.


The Titanic just hit an iceberg. Is Captain Smith, er I mean Captain Mann going to go down with the ship or is he elbowing his way to the lifeboats screaming that the data was bad.

James Sexton

Now that’s a shocker. Next, we’ll have a study about how recent warming isn’t unprecedented.

Mike Lewis

Bah, humbug. All those drowning polar bears beg to differ.

Latimer Alder

How did the poor cuddly wuddly polar bears survive all the time there was less ice? Did they learn to swim? Could today’s bears do the same? b
Or was nice Mr ex-Vice President Gore (Nobel Prize) doing a bit of scare mongering in his film?

Jeff L

The climate debate should always be framed in this sort of longer frame of reference.
Again, geologists & geoscientific research has much to add to the debate.
As a geoscientist, I have been skeptical from the beginning given the general lack of analysis on this time frame.

Pull My Finger

The peer reviewd journal “Rolling Stone” disagrees, says ice is disappearing at an alarming rate! “On Thin Ice: The World’s Two Great Ice Sheets Are Melting Faster Than Anyone Believed Possible” Of course the link I checked takes you to a Shania Twain article. Their web science is of course settled.


Nice to see a scientific article here again. Very interesting post, but I find it curious that the graph shows declining sea ice on a rising scale on the x-axis. “ka” means “per thousand years”, I assume? The use of dinocyst diversity and density provides a compelling methodology to support the conclusions, although I have not seen the data. This appears to be solid geological/paleontological paper. Of course, the implications are frightening, as it does sound as if we might be nearing the end of the holocene interglacial. Yikes!

Philip Finck

Very interesting but not unexpected. I was talking with a retired scientist with the Geological survey of Canada this summer. In the area she studied she said that the tere were times when the temperature was at least 4 degrees C higher than present. I will try to find the published (peer reviewed paper) when I have a chance.


Interesting. The North West passage has been attempted but seldom completed as recorded at the British Library site
and is still being attempted this year by Paul Allen of Microsoft;
Then of course we have the dichotomy of AGW ice loss assisting the potential extraction of arctic oil;
Yet it could be that the best chance of navigable waters has long gone and the next chance is far off. Mother Nature can be so cruel.


It seems that a knowledge of geological history is a necessity today. I don’t want anyone in our school systems, colleges and universities, and scientific specialities without some understanding of Earth’s processes and natural history. This requirement would certainly flunk the entire Climategate crew (CRU).


This was published in 2008. How come it took so long for it to be found?


I see our old friend the misleading baseline on the front chart there, the one that starts at “4” so it looks like 2007 almost saw a complete loss of ice. Sadly, too many people are incapable of even comprehending how they’re being led astray.
Incidentally, global temperatures are essentially meaningless when baseline is 0C. You need to drop that baseline by about 273 to put things in the proper context.

Wayne Delbeke

Slight change in topic, the introduction to the article said “(and never about Antarctic sea ice extent which reached a record high this year)” and I have noticed the recent rather fast drop in Antarctic ice in the WUWT Sea Ice page. I am really curious about this sudden drop and wondering why it is occurring following the record high extent. Seems to be some odd weather about recently.

Theo Goodwin

When global cooling causes humans deaths to increase in serious numbers, who are the first to go? Is it just a matter of being close to the Arctic or Antarctic? Are there large populations on plateaus far from the poles that will suffer greatly? Anyone know?

Rattus Norvegicus

It is interesting to note that the authors said that the trends in the Western Arctic Ocean were the opposite of those shown in the east. It is a kind of difficult paper to read, however, so I have just skimmed it. But it is not surprising that ice extent (actually SST’s) were higher around the time of the holocene optimum. At that time, because of orbital factors, the northern hemisphere received more insolation.
Of course this one will probably show up on poptech’s list of papers which disprove AGW.


No need to think critically about this one – it’s RIGHT!


What I dislike about the historical arguments is that at the end of the day, they largely miss the point –that something else may be causing the 1977-2010 warming, is not to prove that it is. For all we can know from such arguments, perhaps without C02 the 1940-1977 cooling should have continued, and the impact of C02 is actually more than the AGW consensus (to the degree there is one).
But still, the exercise is necessary, because the AGWers insist that all this is unprecedented, and rely heavily on that supposed “fact” to make their argument. So in the end I hold them responsible for having to continually have these fights over the history.
What’s sad –and possibly even dangerous– is that by placing so much reliance on those arguments, the AGWers are liable to discredit their cause whether it needs discrediting or not.
But I continue to believe that another 10 yrs or so of data and research will probably settle this stuff one way or another. In the meantime, I remain reluctant to engage in multi-trillion dollar reengineering of our energy supply on that account. “Peak oil” seems a more credible threat than AGW to me, but of course you’d have to stop demonizing coal and natural gas to do your best to meet that threat.


Get ready for the usual mantra from the alarmist camp when forced to consider this report.
“Past warming does not mean the current warming is not anthropogenic.”
Agreed, but it clearly disproves that the current warming can ONLY be anthropogenic.


Serreze and Joe Romm: Let’s quote Chateaubriand when he saw Talleyrand -Diplomat- walking with Fouche -Police Ministre-: “Here comes vice resting on crime’s arm”… LOL

R. Craigen

I’m on the edge of my seat waiting for Mann and Schmidt (etc) to start complaining that these graphs hold no water because they paste instrumental data onto the end of a graph of proxy data. (Hiding a decline, maybe?)
Altogether now, “three, two, one…”

Alex the skeptic
This link contains a multitude of proxies for various areas of the globe, all showing that:
The MWP was global,
That global warmings and coolings are on a sinusoidal waveform, and
That climate does not depend on CO2 levels at all.
I had stopped worrying about catastrophic GW some years ago, when I had to time to start reading about what was really going on. But then I started worrying about global cooling when I saw this:
If one were to plot a line joining the lowest points on the troughs of the cooling periods, one will get a downward trend, with each global cooling period getting colder and colder, indicating that the next cooling could be even worse than the LIA. I hope I’m wrong and that the current global warming stays staedy. If the cold takes hold, I bet Al Gore, Mann, Romm and others of the same ilk would still be touring the icy planet putting the blame on CO2 and global warming.

R. de Haan

So we can close the books on the Arctic death spiral now?


It is worth noting that the global sea ice anomaly, currently well over 2mm km2, appears to be the largest deviation ever in the 30+ year history of this series.

R. de Haan

The Emperor is without clothes and if he isn’t careful he’s about to lose his head and his skin as well.

ann r

Re. who will be the first to go, we will all be in danger from cold summers and low harvests. This summer in N. CA local apples and pears were hard hit by late frosts. I have heard numerous friends complain that their tomatoes didn’t get ripe. We picked our grapes but they are still tart. Just a first taste of what might be if it turns colder. S.CA complains they moved from spring to fall without ever tasting summer.

If this had been posted by the other team, I would be very suspicious of the gap. How do we know that the measurements across the gap are properly comparable?


I must admit from the start, that I have just arrived back on my ship (after a couple of sedatives from my doctor (Guinness)), and could not resist mentioning, without reading through this piece, or the comments, that Prof Bob Carter has already made a reasonable case for global cooling. Makes one wonder… peut etre, je reviendrais.

This is good solid science. We need to see much more in the future. I gave up my CJES subscription a number of years ago. I just didn’t have time to read it. It is another piece of the geological jug saw puzzle that informs or should inform, the question of polar ice and Holocene climatic fluctuation. If nothing else McKay et al. demonstrate how much we and that includes not only geologists but climatologists, in fact do not know about the processes and history of them.


Can we discuss this in say 5 years, when the signal will be strong enough to penetrate even (most of) this level of [snip]? Have you seen the graphs for sea ice volume, as opposed to extent? They’re even more telling. We are cooking the planet folks, and it’s not a good thing at all.


ann r says:
September 23, 2010 at 3:40 pm
Re. who will be the first to go, we will all be in danger from cold summers and low harvests. This summer in N. CA local apples and pears were hard hit by late frosts. I have heard numerous friends complain that their tomatoes didn’t get ripe. We picked our grapes but they are still tart. Just a first taste of what might be if it turns colder. S.CA complains they moved from spring to fall without ever tasting summer.

I live in SoCal. This year was the first time in the last 26 years that I had to scrape frost of the windshield of my car in May!! And that at only 2400 ft altitude.
The normal “June Gloom” costal fog has now extended from May to September and has seamlessly merged into late fall coastal fog. Only about 2 weeks total of normal SoCal summer weather.
My tomatoes did ripen. But not in mid to end of June as normal, but finally in mid August.
The figs on my fig tree are still mostly green. In a normal year I get 2 crops during summer and fall.

Ed Forbes

the map re-drawn by the Turk Piri Reis in 1513 with a mostly ice free artic has been of interest to me for many years.

Jim Pettit

After reading many of the “Aha! Gotcha!” comments from the contrarians here, I have to naturally wonder whether many–or even any–of them actually read the paper. Here, allow me to post a few snippets:
1) From the introduction: “There is clear evidence that over the last 30 years the Arctic has been experiencing dramatic environmental changes (e.g., Serreze et al. 2000; Comiso and Parkinson 2004). Most notably, there has been a rapid decline in the extent and thickness of sea-ice in summer and more recently in winter as well”
2) Also from the introduction: “…sea ice has continued its rapid decline, since the AO returned to a more neutral state in the late 1990s, suggesting that anthropogenic
warming of surface air temperatures is playing a role in the loss (Overland and Wang 2005), as now recognized by the Intergovernmental Panel on Climate Change (IPCC 2007″
Too, at least one of the paper’s authors– Ohio State University polar researcher Leonid Polyak–also signed off on a study released earlier this summer which states: ”
“The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few thousand years and (is) unexplainable by any of the known natural variabilities.”


This paper reminded me of the extracts from Alan Wilkie’s 1976 book that Warwick Hughes posted .
Page 51 is very relevant.


Suprise, the alarmists are saying the same thing, only the interpretation is different.
Only it is about the Ross Ice Shelf coming and going.
Guy says the Ross Ice Shelf has dissappeared 30 some times in the last few million years. So times were much warmer than today many times in the past.
Similar to the Chuckchi sea being free of ice, cause the Arctic has been warmer than today many times in the past.
The alarmists are alarmed and the skeptics say don’t worry, be happy.
When you guys get to the Cretaceous, your song will be done.

Come on, warmies, forget the skeptics! It has to be arranged: an annual circumpolar Arctic yacht race, planned several years in advance, like all major sports events. Trophies, live coverage, major sponsorships. Branson will come on board with sponsorship, Soros will be good for some cash, Leo will do the publicity shots from a melty ice floe. (Al can just hand out the trophies, since he’s a bit one-way with cash). You have to do this!

When you figure, in a macro sense, we are near the end of the current interglacial, makes sense.

Yuba Yollabolly

Jim Pettit-
That’s the way it works here.

John F. Hultquist

Original paper for this post has only about 10 pages of text and is worth the read.
This link shows how cores are collected:


I don’t get what’s so comforting about instances when things were warmer millions or thousands of years ago. Why do we want to force a return to those conditions? And what about the rate of change? Has the climate warmed this fast in the past?

“Look, just because it was cold in London, New York, Hong Kong, Paris, Singapore, Tokyo, Sydney, Milan, Shanghai, Beijing, Madrid, Moscow, Seoul, Toronto, Brussels, Buenos Aires, Mumbai, Kuala Lumpur, Chicago, Warsaw, São Paulo, Zürich, Amsterdam, Mexico City, Jakarta, Dublin, Bangkok, Taipei, Istanbul, Rome, Lisbon, Frankfurt am Main, Stockholm, Prague, Vienna, Budapest, Athens, Caracas, Los Angeles, Auckland, Santiago, Washington, Melbourne, Johannesburg, Atlanta, Barcelona, San Francisco, Manila, Bogotá, Tel Aviv, New Delhi, Dubai, Bucharest, Oslo, Berlin, Helsinki, Geneva, Copenhagen, Riyadh, Hamburg, Cairo, Luxembourg, Bangalore, Dallas, Kuwait City, Boston, Munich, Jeddah, Miami, Lima, Kiev, Houston, Guangzhou, Beirut, Karachi, Düsseldorf, Sofia, Montevideo, Nicosia, Rio de Janeiro, Ho Chi Minh City, Montreal, Nairobi, Bratislava, Panama City, Chennai, Brisbane, Casablanca, Denver, Quito, Stuttgart, Vancouver, Zagreb, Manama, Guatemala City, Cape Town, San José, Minneapolis, Santo Domingo, Seattle, Ljubljana, Shenzhen, Perth, Kolkata, Guadalajara, Antwerp, Philadelphia, Rotterdam, Amman, Portland, Lagos, Detroit, Manchester, Wellington, Riga, Guayaquil, Edinburgh, Porto, San Salvador, St. Petersburg, Tallinn, Port Louis, San Diego, Islamabad, Birmingham, Doha, Calgary, Almaty, and Columbus doesn’t mean anything, Those were just regional variations! That’s it, regional variations! Yeah, yeah. Sure, sure! Regional variations! We have this here graph we made up at huge expense PROVING the Earth is getting warmer, you are to blame, and you MUST atone by paying us a carbon tax!” — Officialdom