There’s a lot more misinformation in Joe D’Aleo’s post at WUWT about the decline of Arctic sea ice than just the fake portrayal of Arctic regional temperature highlighted in the last post.
To support his claim that Arctic sea ice decline is just natural variation, D’Aleo makes this claim:
The temperatures in the arctic have indeed risen in recent years and ice has declined, bottoming out in 2007 but it is not unprecedented nor unexpected. The arctic temperatures and arctic ice extent varies in a very predictable 60-70 year cycle that relates to ocean cycles which are likely driven by solar changes.
Has Arctic sea ice extent really varied “in a very predictable 60-70 year cycle”? One can’t help but wonder, since nowhere in his post does D’Aleo show any graph, or point to any actual data, to support that claim.
Let’s look at some actual data. One of the best long-term (on a century time scale) estimates of Arctic sea ice is the Walsh & Chapman data set (described in Walsh & Chapman 2001, Annals of Glaciology, 33, 444-448). It’s based on a vast array of available information, as described in Walsh & Chapman:
The primary sources of the post-1972 data are the hemispheric fields of sea-ice concentration from (1) the U.S. National Ice Center (NIC), whose weekly grids (derived primarily from satellite data) span the period 1972-1994, and (2) the satellite passive-microwave grids from the Scanning Multichannel Microwave Radiometer (SMMR)/Special Sensor Microwave/Imager (SSM/I) period, 1978-97 (Parkinson and others, 1999). As described by Walsh and Johnson (1979), the primary sources for the period from the early 1950s to the early 1970s were the charts of the U.K. Meteorological Office, the Canadian Atmospheric Environment Service, the U.S. Naval Oceanographic Office, the Danish Meteorological Institute and the Icelandic Glaciological Society. For the first half of the 20th century, a primary source was the monthly April-September chart series of the Danish Meteorolgical Institute, digitized by Kelly (1979), and the corresponding wintertime information digitized by our group using the summaryies of ship reports in the yearbooks of the Danish Meteorological Institute. An additional source of data for the first half of the 20th century is the recent digitization of the Norwegian Polar Institute’s sea-ice charts by T. Vinje and R. Colony (Vinje, 1999). Since the Norwegian digital data also include the more recent decades, we added these data to the eastern North Atlantic portions of our grids through 1972, the year when the hemispheric dataset of the NIC was initiated. We also note that the Norwegian dataset extends well back into the pre-1900 period, permiting even longer temporal extensions for the eastern North Atlantic.
Note that they went out of their way to gather information from as many sources as possible. That’s the way real scientists work.
And what did they find? Here is the annual average for Arctic sea ice from the Walsh & Chapman dataset:
Contrary to what Joe D’Aleo claims, arctic sea ice extent does not vary “in a very predictable 60-70 year cycle” — not even close.
What it does do is show variations throughout the last century and more, but the dramatic decline (due to global warming) doesn’t start until the latter half of the century, about 1960. And the decline has accelerated, becoming far more dramatic, since about the year 2000, leading to annual average sea ice loss of around three million square kilometers. Imagine that.
Of course the data are less certain prior to the satellite era, less certain still prior to 1953, and even more uncertain before 1900. But don’t believe that the Brits, Americans, Canadians, Norwegians, and Danes are all so incompetent that they managed to miss some three million square kilometers of ice. That’s not real skepticism, it’s the kind of wishful thinking that only suits fake skeptics.
Walsh & Chapman actually provide a gridded data set, as well as pan-Arctic averages for all four seasons of the year. Here are the seasonal averages:
Arctic sea ice has declined — dramatically — in all four seasons. But in none of the seasons is there any sign that it varies “in a very predictable 60-70 year cycle” — not even close.
In fact the summertime average has dropped to about half its value throughout most of the 20th century. Imagine that.
Perhaps Joe D’Aleo actually believes in the “very predictable 60-70 year cycle” which isn’t supported by any evidence. Maybe he truly believes that the Brits, Americans, Canadians, Norwegians, and Danes are all so incompetent that prior to the satellite era they managed to see twice as much Arctic sea ice as was really present during the Arctic summer. Who knows, maybe he even believes the fake Arctic regional temperature we discussed previously?
For anyone keen on records, if not ‘data’, from earlier periods, Patrick Lockerby did a nice history of science piece on the Arctic last week.
I’ve long wondered how those arguing that the recent decline in arctic sea is natural cyclical variation can explain the long history of failed attempts to explore the northwest passage by sea. Many of the world’s most experienced and best equipped sailors died in these attempts because they became stranded and iced in for years at a time.
Keep in mind that they would time their expeditions when ice conditions were the most favourable.
Oh no, the cycle is obviously 590 years: 1421 (http://www.amazon.com/1421-Year-China-Discovered-America/dp/006054094X)
That would put the previous times of ice free passages to A.D. 831 (Vikings found the Iceland), 241 (Roman economic subprime Crisis of the Third Century) and 350 BC (Etruscans get too fat for too good a harvest and get defeated by Romans), 940BC (demise of the Sea Peoples in the Atlantis mountain tops) , one just has to read the signs properly.
Hey, I like this one. It’s a keeper for future reference.
Maybe . . . uhhh . . . maybe, just maybe the 60-year cycle is, uhh, starting, uhhh ermmm, right now! Yeah, yeah, that’s the ticket–right now. In sixty years, you’ll see the cycle and Joe will be a hero, yeah, a hero, that’s the ticket.
Perhaps Joe means “60-70 year cycles with random periodicity, subject to significant but irrelevant noise, and only detectable when using a running 100-year mean.”
He would have had to spend weeks carefully picking through records to construct a data set that gave him that result. Whaddaya say, Joe? Care to share? I’ll be impressed, I promise. I doubt I’ll be convinced, but there’s always a chance that the methodology is sound.
Well, those Atlantic Leprechauns can be capricious!
I know hard rock geologists who work in west greenland who seem to think that the presence of Viking ruins in valleys which are currently iced up suggests substantially more glacial extent now than then. They also mention something about open Nw passage during the holocene warm period. Do you know what this is about? Of should I just suggest to them to go on the denialist talk circuit to raise their research $$, now that climate has sucked all the funding out of non-applied geology?
“Do you know what this is about?”
Um, frankly, no.
Specifics would help. What valleys, and if they’re iced up now, how do we know that there are Viking ruins down there–if indeed glacial scouring hasn’t obliterated them. . . ?
And who says the NW passage was open during the Holocene, exactly?
I’m aware of some evidence that there have been relatively ice-free areas in the high Arctic at some points during the Holocene (and that solar forcing was greater in some parts thereof, according to Milankovitch-style calculations), but it’s pretty hard to have a discussion without a bit more precision. So who said it, why, and what timeframe are they talking about?
You know, details like that. . .
So far as I know, there are no ruins overrun by glacier ice in either settlement in Greenland. It’s a bit of a non-sequiter really, because had they been so, they would not be recognisable as Viking ruins when the ice retreated, and certainly not discoverable if they are under ice now. Vikings didn’t tend to locate their settlements all that near the ice, for a variety of practical reasons. There are a few settlements down-valley of large terrestrially-terminating Greenland outlets, but even these are mostly at least 3km from the present ice margins. This is not unusual in regions with large outlets that descend to lowland areas – similar settlements can be found in Iceland (e.g. Skaftafell or Hoffell) and Norway. So sadly it seems your friends are off the mark here.
Thanks. I spent about two hours searching for corroboration on this–feeling skeptical “because had they been so, they would not be recognisable as Viking ruins when the ice retreated, and certainly not discoverable if they are under ice now,”–as you said.
I found that there were three settlements known from the Norse historical record, the so-called Eastern, Western and Middle settlements (in descending order of population and longevity both.) There are numerous known ruins within the known (and ice-free) boundaries of each–ca. 400 for the Eastern Settlement. (By the way, intuitive nomenclature would have had it as Southern, Northern and Middle–but I digress.)
Interesting to me is the Western Settlement, which was abandoned (? depopulated, at least) in the mid-fourteenth century.) It centered around current Nuuk, the capital of Greenland today. Nuuk (formerly Godthab) was founded in Hans Engede in 1728, and has been continuously inhabited since–which makes it a couple of years older than Savannah, Georgia.
Duh. “By” Hans Engede–he was a person, not a place. . .
And sorry for the superfluous parenthesis.
It’s a bad day for typos, apparently.
Why would one expect hard rock geologists to be experts regarding Viking settlements in Greenland?
Because Hard Rock Hell III was called the “The Vikings Ball”??
I’m a climatologist who works in an Earth Science Department. We’re the minority around here. The place is overrun with geologists, seismologists, petrologists, geo-chemists (many of whom are about as blue-sky as one can be)…. Every week there is a seminar with “zircon” or “regolith” or in the title.
So if us climatologists have “sucked all the funding out of non-applied geology”, how is it that my hard-rock colleagues are continuing to draw a salary? How is it that many of them still find the cash to spend 3 months of the year in the Himalayas (or Greenland… yes I know people who work there too) on field work. Who is coughing up the dough for their new supercomputer so they can fiddle with their inverse models? Maybe my boss is giving them some of his “UN communist conspiracy” money on the sly?
If you want to say that climatology is overfunded, go ahead, make that argument. But you might want to provide a bit of evidence other than the little birdy tweeting on your shoulder.
Thus it can be concluded that the high magnetic field produced by Chariclo-Chiron interaction blocks the GCRs in a predictable manner thus driving the individual cyclone formation on earth. To get the control of the weather back, there should be an ‘Armageddon’-style mission to destroy the alien magnetic field generators located there. I want credits to the end credits of the film if its produced :-P.
tamino, what do the five rightmost columns in the data page represent? There are no headers.
[Response: Yes, the lack of headers is troublesome. The columns are average ice extent for: Annual, Winter, Spring, Summer, Autumn.]
It is also worth noting that the ice if we extend our view to the Arctic glaciers is not bottoming out either. Greenland and the Canadian Arctic islands are continuing to lose ice mass. Box and Decker (2011) note the loss of area of the largest glaciers in the last decade 1590 square km. This loss is not confined to one type of glacier, and is ongoing, such as on Upernavik Glacier . Gardner et al (2011) note the same trend in the Canadian Arctic.
Box and Decker 2011 was not included in previous post.
Lab Lemming; Why would anyone deny a variation in Greenland’s ice cover? Since you seem to be so interested in it, but not interested in the cause, can you assure us the cause for previous variation is the same as now, or that all variations of interest are causeless?
The part of Greenland would be the Archean craton, which is +/- 300 km or so N and S of Nuuk, on the west coast.
I’m afraid I can’t give you particular fjord or ruin names.
I’m not gonna name names, but there are lots of people who have worked in that area since the mid-90’s, when the putative oldest sign on life paper came out.
I don’t really care all that much, I was just curious, since it was the first dismissive comment I had heard from someone who has actually spent lots of time in the arctic.
Why do you stop your graphs on 2007 did you think no you would notice???
[Response: The Walsh & Chapman dataset only goes up to 2007. I showed all of it.]
We certainly noticed the careful syntax and grammar, and the courteous tone and punctuation of the question.
Maybe he was talking about a unicycle
Or a Pogo shtick.
Could someone tell me who this wmar guy is who posts on Dot Earth? Is it D’Aleo?
Indistinguishable from Marc Morano as far as I can tell. He’s been there forever, and never deviates from providing the most complex and polite disinformation possible. Doesn’t matter who he is, and feeding him just makes him do more. He *has* to be a professional as he wouldn’t otherwise have enough time to be so consistent in promoting his false message.
Don’t know if this sheds any light on the issue but in Stephen Schneider’s book the Coevolution of Climate and Life (1984) in the section on the Medieval Optimum a reference is made to the fact that in the 1920’s and 30’s Norsemen bones were found by archeologists. Not sure where or when they are from but based on the context it seems they were from the one of the mid cooling periods sometime in 1300 -1500. It wasn’t mentioned if these were from gravesites or not.
That is an interesting comment about Nuuk being founded in 1728. That would put it in latter part of the Little Ice Age when I imagine sea ice and glaciers must have been significantly advanced (Schneider quotes Pope Alexander IV on what must have been similar ice conditions around Greenland in 1492). What a time to pick to found a city there. And its still there! Some hearty if somewhat obstinate genes in that town!
BTW, Schneiders book(co-authored with Randi Londer) is an excellent addition to any library on climate science.
Looks like Herjolfsnes was excavated in the 1920s. That would be in the Eastern Settlement, near the southern tip of the island:
Here’s the first page of a review article on the topic:
The Norsemen In Greenland (Wm. Hovgaard)
Should have said that the last written record from Norse Greenland came from the Eastern Settlement in 1408–ironically enough, perhaps, it’s a record of a wedding. It’s not known what happened after that; I saw one source that said the last ship from Norway to Greenland during the Norse era was in 1410, but presumably there’s no record of what she did, what she carried, or what her personnel saw.
I referenced Alexander IV in the previous post it should have been Alexander VI.
Those are some very interesting comments on the Eastern Settlement. It is quite consistent with the recorded papal report as those dates are near the time frame referenced in it.
Quoting Schneider who quotes Pope Alexander VI: from the church in Garda in 1492, “..shipping (to Greenland) is very infrequent because of the extensive freezing of the waters – no ship having put into shore it is believed for eighty years”. The actual letter which can be found online indicates in addition “ ….if such voyages were made surely it is thought they could not have been accomplished save for the month of August when the ice was dissolved” (From The Flatey Book And Recently Discovered Vatican Manuscripts Concerning America As Early As The Tenth Century ).
Settlements can die out for any number of reasons but it would appear the severe climate of those times probably played a significant role in its demise.
Thanks. This is becoming a tempting topic to write about.
Interesting that August is named as the month when ‘the ice was dissolved,’ given that today we see minimum extent in early September. (Maybe the Gregorian calendar reform is relevant here–didn’t dates shift eight or ten days forward in the eighteenth century? Have to check that.)
Tamino, there’s another fascinating Arctic sea ice reconstruction over at the best science site in the world.
sigh – fell for it. I never give them my clicks if I can help it …