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« Hollywood scientists | Main | CMEP: the back story »

Icy news

There have been a few interesting bits and pieces over the last few days on the subject of polar ice, which have left me rather confused, so this piece is by way of a call for assistance.

The story starts with Nigel Lawson taking some potshots at David Attenborough for his global warming episode of Frozen Planet. He made a number of specific criticisms of Attenborough.

Had he wished to be objective, he would have pointed out that, while satellite observations confirm that the extent of Arctic sea ice has been declining over the past 30 years, those satellite observations show that, overall, Antarctic sea ice has been expanding over the same period.

Had he wished to be objective, he would have pointed out that the polar bear population has not been falling, but rising.

Had he wished to be objective, he would have mentioned that recent research findings show that the increased evaporation from the Arctic Ocean, as a result of warming, will cause there to be more cloud cover, thus counteracting the adverse effect he is so concerned about.

Had he wished to be objective, he would have noted that, while there was indeed a modest increase in mean global temperature (of about half a degree Centigrade) during the last quarter of the 20th century, so far this century both the UK Met Office and the World Meteorological Office confirm that there has been no further global warming at all.

This exchange prompted a riposte from Mark Brandon, a scientific advisor to the programme, who sometimes comments at BH as Mark B. Followers of the climate twittersphere may have come across him as @icey_mark. The response was published on Mark's page at the Open University as well as prompting an article at the Guardian by Leo Hickman, curiously timed to coincide with the release of Booker's report last week.

The response was as follows:

There has been a net loss of over a million square kilometres of global sea ice extent since satellite records began

The mean volume of arctic sea ice has decreased by something around 50% since the start of the satellite record.

Only this week a publication in Nature described the loss of Arctic sea as:
"The duration and magnitude of the current decline in sea ice seem to be unprecedented for the past 1,450 years"

The loss of a million sqkm of extent seems plausible to me - I look at the Cryosphere Today global sea ice area graph occasionally, and while this is currently at around zero, it has been around the minus 1-2 msqkm mark in recent years (about 4-5%). This seems to me to be a decidedly unscary kind of figure.

The Arctic volume figure is more interesting. My understanding (based admittedly on only a limited study of sea ice) is that estimates of sea ice volume are a relatively recent development. So my question is: how do we know that Arctic ice volume has declined by 50%? The intrigue is increased still further by a tweet Brandon made a couple of days later in response to Christopher Booker, who had also take a potshot at Attenborough in his column,: referring in the process to a "modest shrinkage of ice in the Arctic"

only Booker could say 30% decrease is "modest" RT : Booker

This raises the question of what this latter figure refers to. Is it volume or area or extent? And over what timeframe? And where does it come from? I haven't been able to get a response from Mark.

If we refer back to the last of Mark B's three points above, the suggestion that Arctic sea ice is at its lowest in 1450 years is also interesting. The paper he cites is none other than Kinnard et al, which is currently the subject of considerable interest at Climate Audit, where the paper's use of tree-ring proxies that are known to be problematic (e.g. Yamal) has raised eyebrows. Doug Keenan has also been interested in Mark's arguments, and has pointed us both to this paper by Willie Soon, which finds what appears to me to be an excellent match between Arctic temperatures and solar irradiance - this would presumably explain the fall in Arctic sea ice.

All this leaves my head somewhat in a spin though. What are the correct figures for the decline in Arctic and global sea ice area, extent and volume, and how good are they?)? And is the Soon paper a plausible explanation?

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Reader Comments (126)

Scientists use models to 'estimate' the volume of Arctic ice going back 30 years or so.

Dec 12, 2011 at 10:25 AM | Unregistered CommenterMac

This is a case of ecoloonies choosing to be effective rather than honest. When they start banging on about "since satellite records began", but fail to mention that this was all of 30 years ago, then you know instantly they're not coming to this in a spirit of honesty.

Dec 12, 2011 at 10:32 AM | Unregistered CommenterJustice4Rinka

Haven't you noticed that among the young, 1970 is before the beginning of time. I referred to "during the war" the other day, to be asked "what war/" I had to give it to the questioner that it was a reasonable question that would never occur to anyone my age or older.

Dec 12, 2011 at 10:37 AM | Unregistered Commenterj ferguson

Some thoughts:

A recent paper by Polyak et al ( agrees with many others that the Arctic ocean was
nearly or perhaps even completely ice free for periods in the summer
during the Holocene Optimum, but has not had such little ice since then. (See also Funder's work: Driftwood, beaches, whale bones etc all
point in that direction. Other evidence has recently concluded that
the July sea surface temperatures in the Chukchi sea were a remarkable
3-7C warmer than today (Darby, D. et al 2001. New record shows
pronounced changes in Arctic Ocean circulation and climate. EOS,
Transactions, American Geophysical Union 82: 601, 607.) during the
Holocene optimum -- implying incidentally that dangerous methane
outgassing from a warming of that magnitude is unlikely. So it would
be a falsehood to call today's melting unprecedented or to imply for
example that greater ice retreat would inevitably cause polar bear
extinction, as many do.

Second, Nordic data, suggests a greater ice retreat in the 1930s than
today in part of but not in the whole of the Arctic. To quote from
Divine and Dick (Divine, D.V. and C. Dick. 2006. Historical
variability of sea ice edge position in the Nordic Seas, Journal of
Geophysical Research, 111, 10.1029/2004JC002851):

``a similar shrinkage of ice cover was observed in the 1920s–1930s,
during the previous warm phase of the low-frequency oscillation, when
any anthropogenic influence is believed to have still been

and the Macias Fauria et al study cited in the Polyak paper more
recently finds a multiproxy Nordic ice extent minimum in the

Dec 12, 2011 at 10:43 AM | Unregistered CommenterMatt Ridley

We have no context in which to view this decline. It is quite possible that it happens rather frequently over the centuries. In fact, during the Holocene Thermal Optimum it was likely there was no sea ice in the Arctic in the summer for 4 or 5 thousand years. There might not have been any there in summer in the MWP either, we just don't know.

Our context goes back only as far as the LIA and the period of our recovery from it (which may not yet be complete) so it would be quite logical that sea ice would generally decline and I would expect it to. And even in a period of general recovery from the LIA we would have periods of cooler temperatures and periods where it warms for relatively brief periods at a rate greater than the mean over that time, but I see no indication that the warming has accelerated. We see a record of periods of warming of roughly 30 years followed by a hiatus of the warming for about 30 years and then it picks up again. According to HadCRUT3 the warming from 1911 to 1942 looks about the same as the warming from 1975 to 2004 and it has been cooling since 2005.

We simply do not have the data to make the claims these people make. If human CO2 emissions aused the warming since 1975, then what caused the warming starting in 1911? In 1920 only 35% of homes in the US were even wired for electricity and only 2% of farms had power. Even then we used it only for lights, maybe a fan and possibly an electric iron and that was about it.

Explain what caused that warming of nearly the same duration and nearly the same degree. Then explain why the more modern warming is any different than that older period, please.

My guess is they can't.

Dec 12, 2011 at 10:44 AM | Unregistered Commentercrosspatch

Here's a link to the reference to my last comment.

Dec 12, 2011 at 10:48 AM | Unregistered Commentercrosspatch

I see the BBC faked some of the polar bear scenes..

Dec 12, 2011 at 10:50 AM | Unregistered CommenterJohn

Didn't Attenborough also predict that the Arctic would be ice free in WINTER in 20 - 30 years time? Surely he meant to say summer, but why hasn't this been picked up?

Dec 12, 2011 at 10:52 AM | Unregistered CommenterRoger Longstaff

What strikes me about the discussions about ice coverage is the relative short period of detailed observations we are expected to abstract definitive information from. If you accept that there has been x amount of global warming (whatever its cause) over the last 30 years then how unusual is even 50% Arctic ice loss given that x level of warming? The obsession with ice coverage seems like an opportunistic obsession with symptoms that allow causes to be forgotten or tacitly implied.

Dec 12, 2011 at 11:03 AM | Unregistered CommenterTS

I just now finished watching Frozen Planet's final episode and I think, although it had a point of view, it was not as preachy or as bad as I expected.

As to how they might know the volume of ice in recent decades, the final episode does say that there are submarine cruise records on the thickness of the ice dating back to 1950s and 60s and Attenborough says "it has nearly halved in thickness since 1980".

As to the "30% decrease", it refers to the change in minimum sea ice cover in the North Pole since 1980.

Dec 12, 2011 at 11:05 AM | Unregistered CommentersHx

I've seen photos taken by the US navy, of a nuclear sub surfacing at the north pole during a summer, early 50's, showing the sub floating among melted ice bobbing in the ocean. No solid, hard, thick ice sheets. Presumably, also, the arctic was ice free in some summer(s) earlier last century.

Most probably that was the situation during the MWP, but there were no satellites or nuke subs (nor SUV's) during those (non0anthropogenic) global warming times.

Dec 12, 2011 at 11:19 AM | Unregistered CommenterAlex

Individual measurements of Arctic ice thickness based on time and place cannot fill in the huge gaps of our knowledge. The satellite record of ice extent coupled with a modelled estimate of overall thickness gives a final estimate of total volume. As with any estimate there is degree of uncertainity. The Arctic is not a homogenous environment. We need only remember the Catlin expedition measuring ice thickness by hand tools and also the German team measuring ice thickness from the air to realise that.

Dec 12, 2011 at 11:24 AM | Unregistered CommenterMac

Don't also forget the tendency to capitalise on other people's ignorance or unawareness of relative sizes.
Scary photos of great big bits falling off Antarctica or Greenland are very impressive and certainly the bits are very big when compared to my back garden. When compared to Antarctica or Greenland they turn out be little more than a flea bite.
The average man in the street doesn't know either how big Antarctica or Greenland actually are or how thick the ice is. Neither are any of the alarmists leaping forward to explain that have bits fall off is perfectly normal for glaciers. Nor are they in a hurry to accept that the state of Arctic ice may well be as much to do with wind and current as with temperature.
The first casualty of the Climate War was indeed truth!

Dec 12, 2011 at 11:36 AM | Unregistered CommenterMike Jackson

A simple search in Bing Images for 'submarine North Pole' returns a vast number of images, some tongue-in-cheek, mostly historical &c.
Seems to be quite the fashion - & not at all unusual.

Dec 12, 2011 at 11:46 AM | Unregistered CommenterEvil Denier

The 50-70 year Arctic freeze-melt oscillation has been known since the 15th Century. it's caused by the build up of iron in dust in old ice. the iron plus dimethyl sulphide from phytoplankton, an evolutionary adaptation. Phytoplankton blooms produce CCN reducing the albedo of clouds thus warming the region..

When this process runs out of iron, the melt rate falls. You can see this in the fall of N. Atlantic OHC:

N. Atlantic OHC:

It's falling as the Arctic goes back to freeze mode.

Sea level:

It's falling as solar output falls and extra ice forms.

Atmospheric temperature going down now:

Mostly natural [solar, biofeedback in the Arctic], net CO2-AGW may well be near zero.

Dec 12, 2011 at 11:50 AM | Unregistered Commentermydogsgotnonose

Since for some activists the climate debate is so 'settled' that there is no need to engage with 'sceptics', and risk giving their whacky views the oxygen of publicity, there may be a risk that Mark Brandon will not reply to your request for clarification. If he does, may I commend this site as a convenient source of charts on various climate-related observations, including sea ice: My impression from them is that nothing at out of the ordinary is going on. For example, this plot ( shows the satellite era data highlighted in blue on the rhs for April ice extent (area) in some Nordic areas over the past 150 years.

Dec 12, 2011 at 12:04 PM | Unregistered CommenterJohn Shade

I'm sure Richard Black will have had something gloomy to say on the subject of Arctic ice.

see email # 0859 from 2008.

Dec 12, 2011 at 12:20 PM | Unregistered CommenterMessenger

We need only remember the Catlin expedition measuring ice thickness by hand tools and also the German team measuring ice thickness from the air to realise that.

Dec 12, 2011 at 11:24 AM | Mac

Please Mac can we stick to scientific stuff rather that advert sponged garbage jokes like Catlin and simply be glad they did not need airlifting out!

Dec 12, 2011 at 10:50 AM | John
Saw that about the BBC faking stuff again! Poor bloody German Polar Bears! Cosy and warm in a German zoo but those cuddly little cubs were just to nice to miss huh!

Dec 12, 2011 at 12:21 PM | Unregistered CommenterPete H

There are some good comments in the CA topic regarding the Kinnard O18 paper, including some from Paul Dennis. Being a simple engineer, isotope proxies seem more credible and as he explained, based on pretty sound science. That makes them look like more reliable precipitation proxies which should allow some inference regarding ice state, but I still have doubts about their reliability as temperature proxies. There still seems to be a tendancy to torture data to present tidier stories, especially when there seems to be evidence showing plenty of natural variability for at least Arctic ice.

Given the way climate science has become so polarised and politicised, it's perhaps natural and unfortunate that claims regarding ice extent or mass are met with a degree of scepticism. The NGO involvement and the promotion of pro-AGW results has created an unhealthy environment and possibly a misplaced lack of trust in science. Arctic ice may be at it's lowest extent in 1500 years, but is that as a result of natural variability, or human activity?

The biggest challenge though is still the one Crosspatch et al mentions, the lack of quality data to support what may be extraordinary claims.

Dec 12, 2011 at 12:24 PM | Unregistered CommenterAtomic Hairdryer

This is what the state of knowledge was in 1976

For arctic ice check out page 51

Dec 12, 2011 at 12:25 PM | Unregistered CommenterRipper

I've seen photos taken by the US navy, of a nuclear sub surfacing at the north pole during a summer, early 50's, showing the sub floating among melted ice bobbing in the ocean. No solid, hard, thick ice sheets. Presumably, also, the arctic was ice free in some summer(s) earlier last century.

Most probably that was the situation during the MWP, but there were no satellites or nuke subs (nor SUV's) during those (non0anthropogenic) global warming times.

The photo to which you refer was probably taken during the '30s. See Goddards pages.

Dec 12, 2011 at 12:41 PM | Unregistered CommenterStephen Richards

Ben Pile has an interesting piece on Mark Brandon here:

Dec 12, 2011 at 12:54 PM | Unregistered CommenterHector Pascal

This exchange prompted a riposte from Mark Brandon, a scientific advisor to the programme,

Well, Brandon may - or may not - be correct about the icy stuff. But as Ben Pile has demonstrated, Brandon certainly missed the mark in his claims regarding the ... uh ... decline ... in polar bear population:

The Polar Bear Affair. Part 1001

Dec 12, 2011 at 1:03 PM | Unregistered Commenterhro001

You know the Polar Bear cubs featured in Frozen Planet are kept in a Zoo, what is the standard Zoo procedure for breeding Bears, do they keep the big male bears away from the mother and cubs? if they do then why do they do it, could it be that there is a risk the male would eat them?

From Wiki
Adult male bears occasionally kill and eat polar bear cubs,[78] for reasons that are unclear.[79]

According to the BBC the reasons are not so unclear.

Dec 12, 2011 at 1:05 PM | Unregistered CommenterJace

Here's a post that Anthony did some time ago at WUWT on US subs at the north pole.

There's an interesting colour shot of three subs meeting at the pole in May 1987.

It shows extensive open water around the subs, even at that time of year, and it's obviously genuine since it was signed by the skippers and circulated as a crew memento.

How do climate "scientists" get away with ignoring well known historical events which happened within many of our life times?

Dec 12, 2011 at 1:07 PM | Unregistered CommenterFoxgooose

Sorry, missed out link

Dec 12, 2011 at 1:07 PM | Unregistered CommenterFoxgooose

The "30%" figure comes from the Attenborough final episode (click on "more programme information"):"the Arctic Ocean has lost 30% of its summer ice cover over the last 30 years."

I'm guessing that the reference is actually to minimum ice cover rather than an average. While I couldn't locate a graph showing the history of the actual ice extent (or area) mimimum, but NSIDC have the average September sea ice extent over the satellite era (last 30 years), up to and including 2010. It indicates a 30% reduction over the interval. They provide a brief discussion here.

Dec 12, 2011 at 1:10 PM | Unregistered CommenterHaroldW

HaroldW said: ...I couldn't locate a graph showing the history of the actual ice extent (or area) mimimum...

Is the the sort of information you're looking for?

The 30% reduction (loss?) value seems to be with reference to the Arctic summer minimum value, though the winter maximum is clearly far less. Moreover, the 2007 minimum -- the one that got everyone so concerned -- seems to be more of an outlier than part of a trend, though the relatively small measurement history makes it difficult to draw any hard conclusions.

Dec 12, 2011 at 1:32 PM | Unregistered CommenterDave Salt

Alex and Evil Denier

Crew member, USS Skate (emphasis added):

the Skate found open water both in the summer and following winter. We surfaced near the North Pole in the winter through thin ice less than 2 feet thick. The ice moves from Alaska to Iceland and the wind and tides causes open water as the ice breaks up. The Ice at the polar ice cap is an average of 6-8 feet thick, but with the wind and tides the ice will crack and open into large polynyas (areas of open water), these areas will refreeze over with thin ice. We had sonar equipment that would find these open or thin areas to come up through, thus limiting any damage to the submarine. The ice would also close in and cover these areas crushing together making large ice ridges both above and below the water. We came up through a very large opening in 1958 that was 1/2 mile long and 200 yards wide. The wind came up and closed the opening within 2 hours. On both trips we were able to find open water. We were not able to surface through ice thicker than 3 feet.

Let's be careful not to misrepresent the 'US sub surfaces at pole' stuff, shall we?

Dec 12, 2011 at 1:48 PM | Unregistered CommenterBBD

Dave Salt --
Thanks, that's almost what I was seeking, but it shows only the last few years, rather than the full history as NSIDC have. However, the NORSEX chart *does* have the 1979-2006 average, and the ice area (at minimum) averaged around 6.0 million sq km, while the 2011 minimum was around 4.0, which confirms a reduction of around 30%. Actually, it seems to yield a slightly stronger reduction, as the NSIDC chart declined 30% from start to end (on the trendline); the NORSEX data declined ~30% from *average* to end.

Dec 12, 2011 at 1:52 PM | Unregistered CommenterHaroldW

Poor old Attenboro seems a decent enough cove, but I wish he would get his teeth fixed to stop that distracting sibilance.

Presenters aren't really the culprits - some years ago a fail on Question Time picked up Dimblebore's earpiece and transmitted the feed to him from the director's box - giving the game away. I assume Lawson's potshots were using Attenbore as a proxy target for the whole production team.

Dec 12, 2011 at 2:10 PM | Unregistered CommenterFilbert Cobb

Great thread, to which I have only this to add: the Radio Times mispelled Jonathon Porritt's first name as Jonathan. My sympathies are entirely with the magazine and its sub-editors. What is it with Jonathons and Jonathans? Isn't there some way to introduce a global agreement at least on this one thing, where Jonathan Jones can sit down under his own fig tree, as far as possible from an ice cap, in harmony with Porritt and all the others?

Then it'll be the Alistairs and the Alastairs I suppose.

Dec 12, 2011 at 2:17 PM | Unregistered CommenterRichard Drake

HaroldW, maybe this graph provides you with more insight...
...and, possibly, the hint of a long-term trend.

Dec 12, 2011 at 2:22 PM | Unregistered CommenterDave Salt

The NSIDC page seems to give just part of the info. Here is a page from Real Science showing more of the yearly ice thickness readings:
and here is Steve Goddard again with a nice superposed "Mark Sereze Death Spiral" graph on the ENSO, at the top of page 10 -

Dec 12, 2011 at 2:23 PM | Unregistered CommenterBrady


It is interesting to note that Arctic ice extent grew by 12% from 1960 to 1970.

So it raises the question does the Arctic ice extent and volume go through large changes in very short periods?

Dec 12, 2011 at 2:27 PM | Unregistered CommenterMac

Don't trust RealScience; it's the most finely spun science that the carbon traders can buy.

Dec 12, 2011 at 2:33 PM | Unregistered Commentermydogsgotnonose

Clearly the Good Sir David hasn't heard of Sir Joseph Banks, President of the Royal Society in 1817, who wrote a letter to the Lords of the Admiralty in that year advising of the ice that "was much abated" as a result of a "new source of warmth" at the time!!!! Makes that 1400 years claim pretty hollow IMHO.

Dec 12, 2011 at 2:35 PM | Unregistered CommenterAlan the Brit

Sorrry for being slightly off topic, but there is a new lecture by Michael Mann discussing among other things climategate, the stick and his own FOI troubles. He also hails the climate model of Hansen (1988) and conveniently decides to cut actual temperatures at 2005. He also feels that The hockey stick came under attack, not by bloggers or scientists, but by "politicians":

Dec 12, 2011 at 2:47 PM | Unregistered CommenterKTS

Whether or not sea ice in the Arctic is at the lowest in 1,450 years is irrelevant.

It was considerably lower in the "Holocene Optimum" of only 6,000 to 8,000 years ago, the warmest point in our current interglacial, which would be sliding inexorably toward the next ice age were it not for our current CO2 and other emissions. (That isn't an argument for unlimited emissions, only pointing out where we are in the current interglacial.)

How do we know the Arctic was nearly ice free, not so long ago? From articles in the last year pointing out that in the Holocene Optimum, there were the markings of large wave action on the Northern Greenland coast, which could only happen if the Arctic were mostly ice free for parts of the summer. That hasn't happened, to my knowledge, since about 6,000 years ago. Other articles show that wood from Siberia got transported to Northern Greenland during the Holocene Optimum. Again, this doesn't happen when the Arctic is mostly covered with ice in summer, as it still is today.

What would happen if the Arctic did become close to ice free during a couple of weeks in summer, and lost considerably more ice for a few months, compared to today? Polar bears and other Arctic life survived quite well it seemed, during the Holocene Optimum, as they did during the entire previous interglacial, 110,000 years ago, when sea levels were up to 7 feet higher than today.

When alarmists want to alarm you, they go back only as far as it is convenient for their own argument. They won't tell you, naturally, that going back another millisecond in geologic time destroys their argument.

Dec 12, 2011 at 2:53 PM | Unregistered CommenterJohn

There is strong evidence that the Arctic, in relatively recent times, has held much less ice than it does now. There is no correlating evidence showing worldwide climate crisis in that period.
The ice fear, like each and every AGW claim, when examined, shows to be yet another diversion from the central question:
Where is the climate crisis?
The AGW community and their promoters, communicators, profiteers and opinion leaders cannot honestly answer that question and maintain AGW's social power, so they distract, dissemble, fib, tell each other comforting lies, etc.

Dec 12, 2011 at 2:59 PM | Unregistered Commenterhunter

Also a very interesting new paper by three Norwegian scientists, utilizing a new metihod of analyzing natural fluctuation, concluding that for the North Atlantic/Arctic, natural cycles are sufficient to explain the modern warming without any anthropogenic input.

The method will now be put to the test for other regions.

Dec 12, 2011 at 3:04 PM | Unregistered CommenterKTS

Here is a link for an article referred to in my previous post:

And here is a paragraph from it:

Beach ridges and wave breaking

The team also examined the beach ridges along the coast. Today, perennial ice prevents any sort of beach from forming along the coasts of northern Greenland. But this had not always been the case. Behind the present shore long rows of beach ridges show that at one time waves could break onto the beach unhindered by sea ice. The beach ridges were mapped for 500 kilometres along the coast, and carbon-14 dating has shown that during the warm period from about 8000 until 4000 years ago, there was more open water and less coastal ice than today.

Dec 12, 2011 at 3:04 PM | Unregistered CommenterJohn

I recall a number of references in some texts to Russian northern ports data with sea ice records going back about 150 years. I recall Russian scientists stating periodic behaviour on the order of 70 years. I'll see if I can track down the references.

There is also evidence that warming/cooling of arctic and antarctic are in anti-phase. Sea ice in antarctica is entirely different to arctic but both of course strongly affected by winds and currents.

The latest on the Arctic from :

Overview of conditions
Average ice extent for November 2011 was 10.01 million square kilometers (3.86 million square miles), 1.30 million square kilometers (502,000 square miles) below the 1979 to 2000 average. This was 170,000 square kilometers (66,000 square miles) above the average for November 2006, the lowest extent recorded for that month in the satellite data record.

At the end of November, ice extent remained below the 1979 to 2000 average in the Chukchi, Barents and Kara seas, and Hudson Bay was still nearly ice free. Ice extent was near average in the East Greenland and the Bering seas. These ice conditions may be connected to a strong positive phase of the Arctic Oscillation, which began during the last week of November. A positive Arctic Oscillation tends to help move ice out of Fram Strait and into the North Atlantic.

That seems to me a pretty fair comment. The real question is do we believe nature goes in cycles? I know I do.

The Chilling Stars by Svensmark and Calder has some great examples of roman and bronze age artefacts being found on ice free alpine passes that were under permanent snow during LIA.

As I understand it Anatarctica is currently accumulating ice (not sea ice) and of course sea ice is ephemeral and has no impact on sea level etc.

As for Polar Bears, does the BBC and Attenburgh think they have only been around for 5,000 years? How do they think they survuved the Holocene?

Dec 12, 2011 at 3:35 PM | Unregistered CommenterThinkingScientist


But by the same token, do not overplay the admittedly good evidence from a "crew member". How scientific were his observations? over how long a period? Etc etc. I am trying to recall a reference - probably from RV Jones the WW2 boffin - about how sending scientists to sea to make observations was always more useful than relying on seamen to do the observations. I think it was in the context of sweeping magnetic mines.

Dec 12, 2011 at 3:57 PM | Unregistered Commenterdiogenes

This is probably too simple a question, but is the loss of arctic ice since 1979 unprecedented? Please show your data. Models are not proof.

Dec 12, 2011 at 4:11 PM | Unregistered Commenterdp

Let's be careful not to misrepresent the 'US sub surfaces at pole' stuff, shall we?
Dec 12, 2011 at 1:48 PM BBD

You're being obtuse, as your extracted quote makes clear.

Nobody is claiming the fact that US subs regularly found thin ice and open water at the pole in spring and winter speaks to the overall extent or volume of ice - but it certainly makes a nonsense of the bullshit that "expeditions" like Caitlin bring back like "we almost reached the pole and the ice was less than half the previous thickness............. blah..blah..blah".

The point the sailor was making was that the wind shifts the ice around all the time and therefore drawing climate change conclusions from patches of open water or thin ice is not scientific in any way.

Dec 12, 2011 at 4:39 PM | Unregistered CommenterFoxgooose

I read that the submarine ice thickness data is based on the 'Gore box' which was an area of the arctic that Gore released when VP. So it compares the sonar levels from 60s to now...showing the ice was 30% 'thinner'.....this I think was what DA was stating.

However.........being Al Gore, its not that simple.

I have also read that the systems on the subs in the 60s read the ice at its thickest points within a given area, not accurate enough to measure the variance....
As we can be 2m thick in one place and yet riven with gaps where it may be only 1m thick. Modern measuring can get an average thickness by seeing these gaps, which in the 60s they could not.

That means the figures could be measuring only the thickest ice in the 60s compared to the average today.

I do not have the links, nor can I remember where I read it, but if someone wants to do a bit of googling you may find the 30% figure relates to this...Al Gore was involved so its natural to suspect a bit of, er, icing the story.

I think the Arctic has less ice than it has done in recent years, but I'm willing to bet its no less than it was during the 20s/30s...depends which part of the Arctic you look at of course.
And I'm damned sure its got nothing to do with CO2 anyway.

Dec 12, 2011 at 4:44 PM | Unregistered Commentermikef2


As a former submariner, I'm siding with BBD on this one. Old photos of US subs surfaced at the North Pole are irrelavent to any discussion of extent or thickness of artic ice.

Dec 12, 2011 at 4:50 PM | Unregistered Commentertimg56


I think it was Charles Goodeve who said something like that. Reg Jones was a radar expert, but Goodeve did most of the anti-magnetic mine work and went on to be a leading light in the Admiralty's Department of Miscellaneous Weapons Development.

Dec 12, 2011 at 4:53 PM | Unregistered CommenterSalopian

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