Showing posts with label LIA. Show all posts
Showing posts with label LIA. Show all posts

Monday, November 28, 2011

Climategate 2, more unethical Team behavior

The second batch of e-mails, (Climategate 2)(you have to register) documenting the “behind the scenes” activities of the scientists that have been some of the stronger advocates for the uniqueness of current global warming over the last two millennia have been released. They have now been perused in running series of posts at various blog sites, and, while there is no immediately obvious major new revelation, the contemptible behavior of these purportedly exemplary individuals is getting an increasing amount of sunlight. It also shows how thick the whitewash was in the “enquiries” into scientific misconduct that followed the release of the original, Climategate 1, e-mails.

As an example, New Zealand Climate Change has shown in two posts ( here and here) how “reputable” scientists (Phil Jones, Michael Mann, Jim Salinger, Tom Wigley, Barrie Pittock, Mike Hulme and others – i.e. "the Team") worked to get Chris de Freitas, then editor of the journal Climate Research fired from that position, and also worked to try and get him fired from his academic position. His “crime” was to allow, following peer review, a paper that challenged the validity of the initial Mann “hockey stick” paper and its conclusions that the late 20th century was the warmest of the last millennium. (That particular conclusion was later changed, by Dr Mann, though much later than these events).

To explain the heinous nature of this particular activity requires some background, and also some information that has only since emerged. And, for the sake of brevity I am only going to summarize the story, though adding some detail not in the NZ post.
At the beginning of the story, back in 1997, the state of historical climate science thinking was that between AD 900 and AD 1300 (roughly) the world was going through a warming period, roughly akin to that we are currently seeing, and known as the Medieval Warming Period (MWP). This was followed by a much colder period that lasted from AD 1400 to AD 1800, known as the Little Ice Age (LIA). Evidence for this can, for example, be found in a study that was carried out looking at the sediments laid down in lakes in Finland. In 2005 Mia Tiljander submitted her thesis on these sediments in which she found, in concurrence with earlier studies of sediments in other lakes in the region that:
During the Roman period there was in AD 140-220 an 80-year-long period in the Lake Korttajärvi area when organic matter deposition and the sedimentation was similar to that during the Medieval Warm Period (MWP), interpreted as milder climate condition. After this period, a clear mineral matter – organic matter varve structure existed, until the beginning of the MWP.

The MWP, AD 980-1250, was an exceptional period. The MWP is characterized by thinly laminated varves rich in organic matter, almost lacking the mineral pulses (i.e. spring floods), indicating mild climatic conditions. This period was interrupted by a colder period from AD 1115- 1145, dominated by mineral-matter-rich varves. The sediment deposited during the MWP was highly organic and dark brownish in colour. Based on pollen and diatom studies (Kauppila 2002), the MWP was a two-stage event. AD 980-1100 was warm and dry, a cold spell (AD 1115-1145) interrupted the warm trend and the following period AD 1145-1220 was again warm and even drier than the first stage.
In light of subsequent discussion of her work (which comes later) it should be noted that the disturbance of the annual sediment layers (the varves) by human activity only occurred in sediments after AD 1720, i.e. towards the end of the LIA. The picture of the historic climate can thus be outlined, as it was understood, by a plot from the first IPCC report.

Global Temperature plot from the first IPCC report (IPCC via John Daly )

This picture was challenged with the publication by Michael Mann, Raymond Bradley and Malcolm Hughes of a paper in Nature in 1998 (MBH 1998) that introduced the “Hockey Stick” plot to the world. Contrary to the prevailing opinion this paper suggested that there was a steady decline in temperatures from 1000 AD to around 1850 AD (the handle of the hockey stick), following which temperatures rose steadily to their present high levels (the blade).

The original “Hockey Stick” from MBH 1998 (MBH via John Daly ) (Note the thickness of the green error bars).

This plot made it easier to argue that current temperatures were a direct cause of industrial activity, due to the generation of increasing levels of carbon dioxide as the world used more fossil fuel. And, as a result, MBH concluded:
Our results suggest that the latter 20th century is anomalous in the context of at least the past millennium. The 1990's was the warmest decade, and 1998 the warmest year, at moderately high levels of confidence.
This conclusion and the elimination of the MWP and LIA, despite the fact that the curve and conclusion over-rode the combined papers of hundreds of scientists who had worked to validate their existence, was seized upon by the Global Warming community and used without further discussion, as the “New Bible.” It was, for example, prominently featured in the 2000 Third Assessment Report of the IPCC. I have seen it used by the current Secretary of Energy as the valid plot of temperatures over the past millennium and thus as justification for the programs he espouses. And this despite the torrent of valid criticism of the curve, and that the original plot only referred to the Northern Hemisphere.

To sustain the credibility of this plot, the warming of the MWP, and the cooling of the LIA, had to be minimized. Both the initial set of e-mails and the new set document that the Team recognized and worked to do this. One immediate challenge was to respond to a paper published in 2003 in the journal Climate Research by Willie Soon and Sallie Baliunas which had looked at some of the previous data (which MBH 1998 had neither considered nor shown invalid) to conclude that:
Furthermore, the individual proxies can be used to address the question of whether the 20th century is the warmest of the 2nd millennium locally. Across the world, many records reveal that the 20th century is probably not the warmest nor a uniquely extreme climatic period of the last millennium.
Such effrontery and direct challenge to the authority of the team could not go unanswered, and the Team swung into action, (e-mail 31 ). It is interesting to note that in that correspondence Phil Jones recognizes the work of Jean Grove, an early climate scientist, (who reviewed the data validating the presence of The Little Ice Age in an excellent seminal book), but who died in 2001).
What we want to write is NOT the scholarly review a la Jean Grove (bless her soul) that just reviews but doesn't come to anything firm. We want a critical review that enables agendas to be set.
Which was not how I remembered the text at all, and so I re-read the beginning of that book, and it shows that he was wrong in that statement. Dr. Grove wrote:
Historical evidence of Little Ice Age events is much more plentiful in Europe than elsewhere but the documentation from other continents though scantier, is supported by a great volume of field evidence (e.g. Hope et al 1976, Hastenrath 1984) which is presented in Chapters 7, 8 and 9. It emerges that the Little Ice Age was a global phenomenon and it is shown in Chapter 10 that it was not unique to the Holocene.
But it was not just enough to write a rebuttal paper (which would be normal scientific practice). Although a rebuttal paper was written, with Tom Crowley suggesting that it be in EOS, this was not considered sufficient. Beginning with an e-mail from Mike Hulme (e-mail 2272) ) the Team began to focus on the editor, Chris de Freitas, who had accepted the paper.
Whilst we do not know who reviewed the Soon/Baliunas manuscript, there is sufficient evidence in my view to justify a "loss of confidence" in the peer review process operated by the journal and hence a mass resignation of review editors may be warranted. This is by no means a one-off - I could do the analysis of de Freitas's manuscripts if need be.

I am contacting the seven of you since I know you well and believe you may also have similar concerns to me about the quality of climate change science and how that science is communicated to the public. I would be interested in your views on this course of action - which was suggested in the first place my me, once I knew the strength of feeling amongst people like Phil Jones, Keith Briffa, Mike Mann, Ray Bradley, Tom Crowley, etc. CSIRO and Tyndall communication managers would then think that a mass resignation would draw attention to the way such poor science gets into mainstream journals.
Pressure was brought to bear, initially forcing changes in the editorial practices at the Climate Research journal, and then leading to the resignations of the editor in Chief (Hans von Storch) as well the one who accepted the paper (Chris de Freitas), and two others (Clare Goodess – who was at the University of East Anglia with the CRU group and Mitsuru Ando) who protested the publication, and who were encouraged to resign by the Team (e-mail 4808). It led to an editorial by the publisher, explaining why they could not allow the publication of papers in the journal to be governed by individuals outside the peer-review process (i.e. Team members).

The lack of objectivity of the editors of the journals in which the Team publish(such as Science, for example) is shown by theTeam being solicited by the journals to write opposing articles for them, as a counter to the Soon/Balianas paper. (e-mail 2469).
Phil Jones and I are in the process of writing a review article for Reviews of Geophysics which will, among other things, dispel the most severe of the myths that some of these folks are perpetuating regarding past climate change in past centuries. My understanding is that Ray Bradley, Malcolm Hughes, and Henry Diaz are working, independently, on a solicited piece for Science on the "Medieval Warm Period".
Of course, since then, Mann among others, has admitted to the presence of an MWP and an LIA, but it is a little late . . .

The Team were still not satisfied, and as the New Zealand post points out, they suggested that a letter be sent to the head of the University at which Dr de Freitas works, (e-mail 3052)
I have had thoughts also on a further course of action. The present Vice Chancellor of the University of Auckland, Professor John Hood (comes from an engineering background) is very concerned that Auckland should be seen as New Zealand's premier research university, and one with an excellent reputation internationally. He is concerned to the extent that he is monitoring the performance of ALL his senior staff, from Associate Professor upwards, including interviews with them. My suggestion is that a band of you review editors write directly to Professor Hood with your concerns. In it you should point out that you are all globally recognized top climate scientist. It is best that such a letter come from outside NZ and is signed by more than one person.
The e-mail goes on to suggest the form of the letter that should be sent:
Instead we have discovered that this person has been using his position to promote ‘fringe’ views of various groups with which they are associated around the world. It perhaps would have been less disturbing if the ‘science’ that was being passed through the system was sound. However, a recent incident has alerted us to the fact that poorly constructed and uncritical work has been allowed to enter the pages of the journal.

A recent example has caused outrage amongst leading climate scientists around the world and has resulted in the journal dismissing (??).. from the editorial board. We bring this to your attention since we consider it brings the name of your university and New Zealand into some disrepute. We leave it to your discretion what use you make of this information.
The strength of the punishment that the Team inflicted on the journal and those associated with the story kept the peer reviewed papers “in line” for some time, and so it has only this last September (after some 8 years) that it has been necessary to force the resignation of another editor, Wolfgang Wagner, to remind the scientific press as to who is in charge here.

Let me, however, end this rather lengthy post with another piece of Team dishonesty. You may remember that I began by quoting Mia Tiljander’s work on Finnish lake sediments. Well due to an odd circumstance, when this was examined by the Team the results were inverted. As a result, instead of showing the MWP that actually existed, her results were included as showing that it did not.

This was admitted in the first Climategate release (e-mail 3511) where Darrell Kaufman wrote
Regarding the "upside down man", as Nick's plot shows, when flipped, the Korttajarvi series has little impact on the overall reconstructions. Also, the series was not included in the calibration. Nonetheless, it's unfortunate that I flipped the Korttajarvi data.
In fact that is not a completely true statement either, since, as Mia Tiljander noted, the original data clearly showed an MWP, and if the data was good enough to use inverted to disprove that it existed, surely it should also be used to prove its presence when turned the right way around. But as Steve McIntyre has noted on the subject, while the original perpetrator may have submitted a correction the good Dr Mann has yet to admit that he used data improperly.

Courtesy of Climate Audit, you can judge for yourselves, comparing perhaps to the top figure, as to whether inverting the data made any difference.

How using the Tiljander data properly (New) reveals the MWP and LIA (Tiljander via Climate Audit), while the Team use (Old) hides them.

In further discussion the more recent sediments (which Tiljander noted were disturbed) which upticked in the “OLD” incorrect use, continued to be used by the team. As Andrew Montford noted in "The Hockey Stick Illusion", however:
The big selling point of Mann’s new paper was that you could get a hockey stick shape without tree rings. However, this claim turned out to rest on a circular argument. Mann had shown that the Tiljander proxies were valid by removing them from the database and showing that you still got a hockey stick. However, when he did this test, the hockey stick shape of the final reconstruction came from the bristlecones. Then he argued that he could remove the tree ring proxies (including the bristlecones) and still get a hockey stick – and of course he could, because in this case the hockey stick shape came from the Tiljander proxies. His arguments therefore rested on having two sets of flawed proxies in the database, but only removing one at a time. He could then argue that he still got a hockey stick either way.


And a short P.S. Steve McIntyre has just posted that the Team tried the same nasty tricks to try and discredit Willie Soon at Harvard.

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Posted by Heading Out at 1:42 PM 3 comments
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Saturday, November 28, 2009

ClimateGate - and Dr Mann's changing story

The main stream media are still largely hiding the scope of the revelations from Climategate – it is much more important to them, for example, to discuss the couple that gatecrashed a dinner (the Washington Post); that Mayor Michael Bloomberg spent $102 million being re-elected (New York Times); that Tiger Woods crashed his car – but wasn’t hurt (LA Times); or that Pandas got a warm welcome when they moved to Australia for ten years (BBC News).

Commentators have largely tiptoed around the issue. It is interesting to note that Andrew Freedman at WaPo claims to be willing to view both sides, yet puts up interviews with two apologists for the “disinformation” side and promises to put up a skeptical viewpoint “in coming days.” (Perhaps by then the furor will have died down and it won’t have to be too strong a skeptic). And Eugene Robinson is willing to continue the insults:
Stop hyperventilating, all you climate-change deniers. The purloined e-mail correspondence published by skeptics last week -- portraying some leading climate researchers as petty, vindictive and tremendously eager to make their data fit accepted theories -- does not prove that global warming is a fraud.
But unfortunately does not recognize some of the implications to the revelations.
It would be great if this were all a big misunderstanding. But we know carbon dioxide is a greenhouse gas, and we know the planet is hotter than it was a century ago. The skeptics might have convinced one another, but so far they haven't gotten through to the vanishing polar ice.
Well, apart from the fact that the total sum of Arctic and Antarctic Ice hasn’t been changing much – in fact Antarctic ice sheet size has been growing – this fails to grasp an underlying change that is happening among the warmers. (It is perhaps a little early to start to find the same sort of pejorative title for folk that manipulate and hide data to promote their point of view, as has been given to those skeptics such as myself that question some of the data).

In the e-mails that were “released” from the University of East Anglia it is clear that the reliance on tree-ring data, one of the fundamental legs to the data that went into the development of the Mann, Bradley, and Hughes “hockey stick” paper, is unreliable. Those putting out the papers (and judging whether other papers should be published) clearly knew this, but went on using it anyway. As proof thereof Dr Michael Mann and his group have just issued another paper. - but now there is a change. Whereas for the past few years those of us who brought up the existence of the Medieval Warming Period were subject to abuse and ad hominem attacks, it now appears that perhaps the "Power That Is" has changed his mind. In the new paper, the faithful are called to a new recognition:
Mann and his colleagues reproduced the relatively cool interval from the 1400s to the 1800s known as the "Little Ice Age" and the relatively mild conditions of the 900s to 1300s sometimes termed the "Medieval Warm Period."
Of course the paper notes that it wasn’t really that hot back then (though actually there is an e-mail or two that seems to contradict this). So does this mean that those of us who objected to the linear nature of the “hockey stick” line through both this periods will get some admission that we were right. Don’t rush to hold your breath. Nope they don’t have to get that honest! And for those who will head out to Copenhagen waving the original figure – do I anticipate that folk such as Energy Secretary Steven Chu will change his talks – well not really, at that level admitting error almost never happens.

Interestingly one of the things that the “new” review of data that has Dr Mann “discovering” the MWP is that his models now project:
The researchers note that, if the thermostat response holds for the future human-caused climate change, it could have profound impacts on particular regions. It would, for example, make the projected tendency for increased drought in the Southwestern U.S. worse.
Now, and see my cynical nature come through here, I don’t suppose that this has anything to do with the historic record for what happened in those regions a thousand years ago when there were severe droughts that lasted up to a couple of hundred years. (There are tree remnants in the bottoms of lakes as proof I am not making this up).

All those folk who have been saying that the models had shown that there were no major impact due to solar changes are going to have to do a little backpeddling now that the High Priest has spoken:
The warmer conditions of the medieval era were tied to higher solar output and few volcanic eruptions, while the cooler conditions of the Little Ice Age resulted from lower solar output and frequent explosive volcanic eruptions.
It used to be so much easier to make these changes in doctrine, when the vast majority of the populace couldn’t read. But of course there is reading and also there is understanding, and so I anticipate that we will continue to see obfustication and data manipulation for some time to come. And those within the press will take a while to realize that some of the cardinal points that have been used to secure their belief are not, in fact, likely going to prove true.

Unfortunately, at that time, I suspect that folk such as Mr Robinson, will continue to think of those of who demurred earlier as still being evil and wrong, but will just conclude that the scientists that they believed in were also wrong and conclude that scientists as a whole behave this way. It will be difficult to convince them that they are wrong – even as it has proved in the last week, where denial of the meaning of these revelations has remained quite widespread. So what to call those who remain in that state?

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Posted by Heading Out at 1:11 PM 4 comments
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Saturday, February 21, 2009

Honesty in Climate Reporting and Discussion

I am a fan of Edward Tufte’s work. For most of you I suspect that will inspire nothing more than a Huh? But I want to use an example from the global warming debate to show how, by manipulating graphics, you can sell opposing messages with the same set of data. It is this subject (that of graphic manipulation) and the need for honesty in data presentation, about which I feel rather strongly as an academic, that has made me a fan of Edward’s writing.

At the urging of the Advocate, I am going to use a post by Nate Silver (my turn for a Huh?) as my example, and will compare his selected use of segments with, an overall temperature plot from the British Climate Research Unit at Hadley (HadCRU) and with a plot from the Goddard Institute for Space Studies (GISS) in New York., which James Hansen heads. The initial period I am going to look at is from 1940 to 1975. This is the period that initially George Will wrote about, commenting that, in 1975, scientists were looking at the trends and he quoted nine articles from that time with discussions on this trend. So does our friendly critic look at that time period in his commentary – er, well, not exactly!. Here is the GISS plot for about that period:
Source GISS

and this is the more simplified segment of the HadCRU plot.
Source Hadley Climate Research Unit

They’re both small segment of larger plots I will get to in just a minute. And if you look at both you can see (you don’t have to be a rocket scientist) that the trend is down. That was what the scientists were talking about in 1975. So is that what our good friend showed – of course not that wouldn’t allow him to make his point, so he expanded the range, backwards from 1940, into the previous segment of time, including enough points to suggest that the overall plot was upwards (and ergo all those scientists, not to mention George Will, were idiots).

Source FiveThirtyEight

Now you should be able to see that if you knock the data off from before 1940, you will see the same trend as in the earlier graphs.

Now the next bit is a little more interesting, because he pulls back to show that there was a warming trend before 1940, and takes the curve back to about 1860, and, depending on where you define the end points he puts a single warming trend line through the data.


That simplifies what actually went on, looking at both the GISS plot and then HadCRU:

SOURCE GISS

And for the simpler HadCRU



You can see that the way in which the temperature was behaving was not quite the simple plot that has been suggested, but that it fluctuates up and down, and if we break the HadCRU plot into roughly 30-year bits, you can see it drops 1880-1910, then goes up, 1910-1940, then drops 1940 – 1970. So it was really not that easy, back in 1975, to decide where the temperature would go next.

Where it went is now well-publicized, and I will put all three plots up here in full for the next bit.

First the Silver plot:
Source FiveThirtyEight

Now the GISS plot:


and then the HadCRU plot (I showed their entire illustration, lest I be accused of cropping anything):


There are a couple of interesting things to the shape of the lower two curves, that are not clear if you just draw the simple line, that Mr Silver uses, through the data. The first is that it warmed about as much from 1910 to 1940 as it did from 1970 to 2000, in other words the rate of warming was about the same. Not much attention is usually paid to this part of the warming trend – well that is because of this other graph, which is the one that usually gets all the attention.
Source White House Initiative on Climate Change

Now we will forgo for now the discussion about measuring carbon dioxide over an active volcano but you will notice the different slopes for the curve back in the 1910 – 1940 period where we were getting the same rate as we have just recently – curious scientists want to know why? But actually, and more to the point, that graph is a very smooth curve from 1860, as you may note the real temperature data is not.

There are two final points to consider. The first is why I put up the HadCRU and the GISS plots. You may note that at the end of the HadCRU data the curve turns over and starts to go back down. That’s what the data shows. But the GISS plot does not carry the plot that far down. In fact earlier plots of data that just showed the last ten years of data (with 1998 at the peak) disappeared from the GISS site about the end of last year. The differences between the interpretations, and the fact that recent data (in the HadCRU form) does not allow the hysteria about the imminence of doom that comes from the GISS Head, is perhaps why Hadley are now starting utter some words of caution about this whole debate, and that we cannot make misleading claims.

I am going to close with a plot from the 1995 IPCC report that does not get a lot of attention these days, but might explain why the leveling off in global temperature is happening:
Source IPCC 1995 full report

I have written earlier about the Little Ice Age, and will again, and on not only the last warming period, but also the ones before it, for which there is much evidence. It turns out not to be as simple a temperature plot as the IPCC summarized in that plot, but the realities of this cyclic nature of global climate are recorded, not only in books and manuscript, but in archaeological sites, and beneath our feet.

So let's stop with the insults (if you attack a person rather than their science, it concedes the point that their science is stronger than yours) and discuss the volumes of real scientific data that make exactly where we are in the progress of global warming a whole lot more of a question that many people would like you to think.

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Posted by Heading Out at 3:01 PM 1 comments
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Sunday, February 8, 2009

Advancing and Retreating Glaciers in the Holocene

I was musing as to how to start this post, and so I Googled “Medieval Warming Period”, and found that there is a post at Gristmill about talking to an AGW sceptic, that states
There is no good evidence that the MWP was a globally warm period comparable to today. Regionally, there may have been places that exhibited notable warmth -- Europe, for example -- but all global proxy reconstructions agree it is warmer now, and the temperature is rising faster now, than at any time in the last one or even two thousand years.
This is actually a set of incorrect statements. And it epitomizes one of the problems facing those of us that would prefer to have this as a scientific debate about the facts. The problem is the blanket refusal of those who consider that greenhouse gases are the cause of global warming to recognize the considerable body of scientific evidence that contradicts their case.

I am going to be quoting from Jean Grove’s “Little Ice Ages – Ancient and Modern” again in this post, but from volume 2 this time. As with the first volume the book is copiously referenced with detailed scientific studies, the Bibliography runs 70 pages of 2-columns, with about 16 references/column/page, which works out to over 2,000 references on the subject. The subject is as the title says it is, the ice ages of the past millennia, with evidence of their extent and intensity, and their global nature. Between the periods of increased cold, there are periods where it is warmer, even than today. These also are documented, with evidence. The evidence is debated, and weighed as to credibility. It does not require a proxy to show that where a farm existed and there is now ice, that it was warmer when the farm was there than it is now, as an example, or when the advance of a glacier sheared off the trees, to surmise that it was getting colder.

The scope of the work, and recognize that this is a summation of the work of the hundreds of scientists writing the papers that she has combined and integrated, covers largely the advance and retreat of glaciers. In the first volume, which I covered earlier, the main focus was on looking at the last Little Ice Age, and its global impact with glaciers from Alaska to New Zealand growing to new lengths, and then in the early 1800’s starting to contract.

In the second volume the emphasis switches to the Holocene as a whole, namely roughly the past 10,000 years. And, while glacier advance and retreat cannot by itself be taken as a sole indicator of global temperature, some of the concurrent events (the rise and fall of the tree line in the region surrounding the glaciers, and the formation of lakes or peat bogs where glaciers stood, for example) serve as proxy thermometers. As an example, writing about the Engebreen and the main Svartisen glacier
A warm period about 1500 BP (before present) (cal AD 500) is recorded by the growth of pine forest above the present pine limit. Then came ice advances marked by sheared off trees in the period AD 360 -900 (Worsley & Alexander 1975). Although the exact years in which these trees were killed has not been identified by comparing their ring sequences with the long dendrochronological series now available, their radiocarbon dates can be taken as more precise than those derived from soil and peat samples. They demonstrate that Engabreen advanced and retreated several times in this period to form a complex moraine. Karlen (1991) pointed out that the tree ring sequence indicates several temperature fluctuations with cold summers around 550 AD, and again between 780 and 970 AD, though with 20-30 years of summer warmth around AD 930.
In such a manner and going from country to country is the evidence amassed. Karlen, for example, shows that the altitude of pine forests were 100 m above the current limit in the Medieval Warming Period around 1,000 years ago, and that the height of the tree line had varied up and down over 200 m in the Holocene. He concluded that this represented a change of about 1.5 degC.

I have used Greenland as an example of historic climate change in the past, and it is interesting to quote
By about 6,000 calBP the inland ice margin had retreated to a position close to the present (Weidick et al 1990) . . . .Retreat of the ice continued and from at least 4700 to 2700 calPB the inland ice margin was inland of its present position by as much as 15 km. The scale of the retreat is indicated b subfossil shells, reindeer bones and a walrus tusk, brought to the surface by the ice of Jakobshavn Isbrae and deposited in moraines. The reindeer bones which have been dated to 3040 +/- 60 BP must have come from above the snow line over 50 km from the ice margin, and moved westwards in the ice at a rate of about 20 -50 m per year.

The mean annual temperature at Jakobshavn on Disco Bay in the Holocene Climatic otimum is estimated have been about -1 degC, as opposed to -3 degC currently. The great fjord stretching 60 km to the east where the tongue of Jakobshavn Isbrae is now more than 700 m thick, was then free of ice. With readvances probably around 2500 and 1200 BP the ice haltingly returned. Finally, between 1850 and 1880, the Little Ice Age advance culminated, since when the ice has continuously thinned (Weidick 1996).
The front recession has been plotted over the past 150 years, and is shown here.
Retreat of the Jakobshavn glacier

The book continues, going from ice field to ice field as it moves from the Arctic to the Antarctic. Then it plots a curve showing the coincidence of the periods of glacial advance around the world, over the Holocene. Obviously in some parts the work has yet to be done to fully define the periods and details of the glacier movements. Yet the one thing that stands out is that over the past 3,000 years there has been a remarkable consistency in the periods, around the world, when glaciers advanced, and when in the presence of a warming period they retreated.
Regional summaries of glacier expansion (Grove Fig. 15.25)

The book notes the existence of the Dansgaard-Oeschger cycles
The Dansgaard-Oeschger cycles turn out to he bundled into longer cooling cylces, each of which ends with an abrupt shift from cold to warm temperatures. These bundles are known as Bond cycles. It appears that during the abrupt cold-to-warm shifts at the end of Bond cycles temperatures must have changed by several degrees within a matter of decades, both at the ocean surface, and in the atmosphere over Greenland.
Though not understood, the book suggests that the climate change may have been induced by changes in atmospheric dust.

Well, as you can see, the real story is quite different to that which Gristmill would have you believe. Sadly at present there are just not that many folk that will question the statements that they blandly make. I will add the correlative plot from the book in the morning (or rather later in the morning).
Addenda The graphic is added above - fig 15.25.

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Posted by Heading Out at 12:32 AM 0 comments
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Saturday, January 24, 2009

From the Little Ice Age to today -rates of climate change

Much of the media coverage of the changing climate relates to the changes in glacier size, and their relative retreat over the past four decades. In the last Saturday post, I quoted the overwhelming scientific evidence for the presence of a global Little Ice Age (LIA) as documented by Jean Grove.

What I would now like to do is show, through the work of Syun-Ichi Akosafu, of the International Arctic Research Center, that the transition from the LIA to today began long before the considerations of Global Warming and carbon dioxide forcings were much thought of, and, with the backing of the solid science that has documented these changes, that these changes have very little sensitivity to the purported effects of increased carbon dioxide levels. Further I would underline his comment that it is not possible to study climate change without long-term data – considering long term to be not 60 years or even 600, but rather the periodicity of climate changes over the last 3000 years. And that requires archaeological information as well as that of proxies alone, particularly as it relates to those that live in the Arctic regions.


In beginning let me note that as the global temperature, over the last decade, has refused to follow the predicted path of those who espouse global warming, so the period over which average temperatures are defined to denote the trend in climate has been extended, from three, to five, to ten, to the latest fifteen year averages. Let us, for the sake of scientific honesty, decide that five years is a reasonable period over which to define a mean, and then move into the discussion.

Akosafu begins by showing that, if we plot this 5-year mean over the past 140 years, then the trend can be divided into a steadily increasing part (the black line) with, superimposed upon it variations that he calls natural, but that will be examined and discussed as we work through the paper.


Figure 1. Global temperature change, shown as a 5-year average and defined by the overall trend, and the variations thereon. (Akosafu Fig 1e).

Given the whole debate about global warming and carbon dioxide levels, it is appropriate to also include his figure 2, which shows the change in both over the last 150 odd years,
Figure 2. Global temperature (5-year smoothing) plotted with CO2 levels

By comparing temperature records from Vardo, in Norway, with the ice core data from Severnaya Zemlya, he shows that the two can be correlated, and then uses the ice core data to show that the temperature it records has been rising since about 1780. This is then correlated with data from coral studies on the island of Guam that similarly show a temperature rise, which started around 1800. The paper ties this date to changes in the time that ice freezes over lakes and rivers, and when it melts. The conclusion is visibly evident that there has been a change, and that it dates back to around 1800.

However much of the response to mention of both an MWP and an LIA has suggested that the events were localized to Western Europe. Now Grove showed through quotations from numerous papers that this was not true, and Akosafu equally strongly refutes that argument with data from both Peru and China,
Figure 3. Oxygen isotope values translated into temperature variations for both China and Peru over the past 400 years (Akosafu Fig 4c)

While many folk seem to prefer to rely purely on the scientific numbers derived from proxy values, I feel that information from contemporary historical documents can be equally or more valid. Thus the reports of cooler summers between 1550 and 1750, which led to deaths because of the poor harvests, and thus famine, provide information that should not be ignored.

The generality of that condition, and the global evidence of a change to a warming trend after about 1800 is well documented. It is this evidence, and the timing of the start of global warming, that shows that it is a natural, rather than an anthropomorphic change. Anecdotal information, such as the fact that Permafrost formed during the LIA around Fairbanks is only now starting to thaw, does not define the depths of the cold that many places saw and he points out (Figure 6a) that for those many places around the globe, the average temperature in the 1700s was considerably below that modeled by Mann et al, in their famous “hockey stick” paper that formed such a central theme to the IPCC report of 2001. In fact he quotes a table from the NRC 2006 report on global temperatures that confirms, with half-a-dozen plots, that temperature started rising somewhere around 1800. He rightly asks the question that, if CO2 levels did not start rising significantly until 1946, what was the cause of the earlier rise?

If, in fact, one examines the trend of temperature rise from 1800 to 1900 and then from 1900 to 2000 and subtracts the rate of change in existence before carbon dioxide effects are postulated to have occurred, then one finds the pre-existing rate to have been 0.5 degC/100 years following 1800. With the IPCC claim of a temperature rise of 0.6 degC/100 years, then the difference due to CO2 initially appears to be 0.1degC/100 years.

Now if the drop in temperature during the LIA was a total of 1.5degC, such a rate would bring us “back” to date only 1degC. And there are records that suggest that the MWP was, in fact, warmer than today’s temperatures. This, however, only deals with the “black line” portion of Figure 1. Akasofu now looks at the variations around that trend, namely what is referred to as the “multi-decadal oscillation.” This can be seen, in Figure 1, to be an oscillation, but to those anxious to prove Global Warming, it is this oscillation above the underlying trend, coincident with the rise in CO2 levels, that is the marker to our future doom.

However, as an initial point, it should be noted that the nature of oscillations is that, after swinging one way in periodic mode, they then start to swing back. And the phase of the oscillation, as seen from Figure 1, is such as to suggest that the return should begin around 2000 – as it did. This variation is around 0.15degC /10 years, and cycles, as shown, around the mean growth.

Studying the changes that this warming is inducing, Akasofu looks in more detail at the actual specificity of occurrences, rather than the generality. Consider, for example, the reduction in the Arctic ice cap. This is not a uniform contraction, which one might anticipate if the cause were a universal warming, but rather is maximized along the Siberian coast, where the currents from the North Atlantic – under the driving force of the North Atlantic Oscillation (NAO)- have accelerated the melt. The characteristics of that melt – the ice is melting from the bottom, rather than the top, confim that it is a water current related phenomenon, rather than a surface temperature caused result.

In earlier posts I have commented on the retreat of the glacier at Glacier Bay in Alaska, and will take the opportunity of pasting his illustration of this, so that I can refer back to it later. You will note that it shows the glacier retreating to its greatest extent, before 1860.
Figure 4. Glacial retreat at Glacier Park

Similar plots are presented for the Franz Josef Glacier in New Zealand, and the Gangotri Glacier in the Himalayas, as well as the advance and retreat of the glaciers in the west-central Alps.

As I pointed out, when discussing Bangladesh, Akasofu also does an evaluation of the rise in sea levels over the last hundred years, and notes that while the average has been some 1.7 mm/year in recent years, rather than increasing, as one would expect with the glaciers melting, and the ocean warming, in fact the rate has dropped below 1.4 mm/year.

Hidden now, in the heart of the paper, lies some of the more damaging evidence against the modeling of Climate Change that is presumed by so many to be accurately predicting our future.

In the post that induced my departure from The Oil Drum, and as Akasofu confirms, Greenland, as a whole has not been warming in the same mode as the majority of the Arctic regions. When, however, the IPCC Arctic group were asked to run their models to hindcast the behavior of the Arctic regions over the past fifty years, the IPCC models were nowhere near accurate in their predictions of what actually occurred.
Figure 5. IPCC prediction vs reality (on the left)

Further, because the IPCC only focuses on the period following 1975 they neglect the changes in the Greenland ice sheet that occurred during the 1920-1940 period which were substantially greater in magnitude than those now occurring, but which could not have been caused by GHG. And, this after all being an Arctic Research Center, they also point out, contrary to MSM reports that the actual temperature of the permafrost has stopped rising, and in fact the methane levels “off-gassed” have decreased, since about 2000.

I will forego discussion of what might cause the larger cyclic variation (the MWP – LIA cycle) to another time.

So there you have it, to those willing to do "due diligence" on the changes in climate over the past two centuries, the evidence is substantial that the fears so assiduously heightened in the media, are not, in fact, based on fact. We'll get into the MWP and earlier parts of the cycle, in future posts.

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