A 1240-Year Record of Arctic Temperatures

Center for the Study of Carbon Dioxide and Global Change ^

[Exton1]

A 1240-Year Record of Arctic Temperatures

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Reference
Moore, J.J., Hughen, K.A., Miller, G.H. and Overpeck, J.T.  2001.  Little Ice Age recorded in summer temperature reconstruction from varved sediments of Donard Lake, Baffin Island, Canada.  Journal of Paleolimnology 25: 503-517.

What was done
Lake sediment cores from Donard Lake, Baffin Island, Canada (approximately 66.25°N, 62°W), were analyzed to produce a 1240-year record of average summer temperatures for this region.

What was learned
Over the entire 1240-year period from 750-1990 A.D., summer temperatures averaged
2.9°C.  Anomalously warm decades with summer temperatures as high as 4°C occurred around 1000 and 1100 A.D.  At the beginning of the 13th century, Donard Lake witnessed "one of the largest climatic transitions in over a millennium," as "average summer temperatures rose rapidly by nearly 2°C from 1195-1220 A.D., ending in the warmest decade in the record" with temperatures near 4.5°C.

The rapid warming of the 13th century was followed by a period of extended warmth that lasted until an abrupt cooling event occurred around 1375 A.D.  The decade following 1375 A.D. was one of the coldest in the record and represented the onset of the Little Ice Age on Baffin Island, which lasted for 400 years.  At the modern end of the record, a gradual warming trend occurred over the period 1800-1900 A.D., followed by a dramatic cooling event in 1900 that brought temperatures back to levels consistent with the Little Ice Age, which lasted until about 1950.  Temperatures warmed during the 1950s and 1960s, whereupon they have trended toward cooler conditions to the present.

What it means
Large abrupt swings in temperature appear to be a consistent feature of climate in this region of the world, with temperatures rising and falling by as much as 2°C in as short a time period as a decade.  Such natural temperature variability demonstrates the high degree of difficulty associated with attempting to separate effects of anthropogenic climatic forcing from those of natural causes.

In contradiction of politically-correct climatology, the study also demonstrates the existence of both the Medieval Warm Period and Little Ice Age on Baffin Island.  And it stands in stark contrast to the climate alarmist claim that the latter part of the 20th century experienced "unprecedented" warming, at least in this part of the world, which is, however, where such anthropogenic phenomena are supposed to be most evident.

Page printed from: http://www.co2science.org/journal/2001/v4n32c1.htm

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Copyright © Center for the Study of Carbon Dioxide and Global Change

[Havoc]

Actually lake sediments and ice cores are very accurate at determining climatic conditions at the time the layer was put down.

Yep, I'm sure they are - so accurate that Glacier Girl would be more than 250 years old by your methodology. Pretty amazing for a P-38 lightning, huh.. Oh, there was at least one B-17 in that grouping as well. Do you suppose they flew Air support for the British Admiralty in the 1700s? Or perhaps the method is as wanting as all the others..

[PeaceBeWithYou]

What is 250/50?

What is the average annual ice accretion for that part of Greenland?

Think about it. Use the brain God put in your head.

[Havoc]

What is the average annual ice accretion for that part of Greenland? Think about it. Use the brain God put in your head.

Average annual accretion - what, now or 50 years ago or a thousand? Oh, right, we don't really know - do we. We can say for sure in places where that has been measured; but, they looked into that before they went digging - and guess what, they were shocked to have to go down 250+ feet to find the planes. Save us the speach.

[Havoc]

She wasn't in a glacier. She landed inland. Do you know anything about it or are you just looking for an excuse.

[AFPhys]

Thank you for keeping a link of those studies. Like WW, I have been keeping myself busy with some other areas of knowledge, and thirty years of following the "global temperature" debate has worn me out a bit.

It will continue to fascinate me that certain people have such faith in their Global Warming Religion. It does not seem to make any difference what arguments or contradictory data have been brought to bear. They continue try to fool people into believing they can project conditions a century from now when they can't even tell me what the weather is going to be here one month from now. When the GCMs don't get the answers they like, they simple tweak a couple of the "free parameters" until they do. Sorry, that is not the way to do science.

I suppose someday or another, one of them will devise a "new theory" that will be able to match the last hundred years' data from honest sources and finally manage to explain why the global circulation models do such a lousy job. The way it has gone the last ten years, though, with the PURELY political "science of global warming scares" taking complete control of the discussion, it would likely be three decades before I could be convinced such a "new theory" would have any more merit than the myriad of stock market simulations that promise that you can make 100% return on your money by stock timing year after year.

The global warming boogymen seem to be in it for one reason, and one reason only now: to take my money, and money of other Americans.

[cogitator]

cogitator worships at the alter of the IPCC. I really can't see how an intellectually honest person can defend the hockey stick theory.

My friend, you're wrong -- the IPCC is not the be-all and end-all of climate science. But as for the hockey stick, I have on very good authority that in two papers -- one about to be published, one likely to be published later in 2005, the "hockey stick" will be verified beyond any shadow of any doubt. Sorry to be the one to break the news to you on that, but that's the way it's going to be. I recommend planning your own personal paradigm shift soon.

[cogitator]

Regarding your reference:

"(1) In drawing conclusions regarding past regional temperature changes from proxy records, it is essential to assess proxy data for actual sensitivity to past temperature variability. In some cases (Soon and Baliunas, 2003, Soon et al, 2003) a global ‘warm anomaly’ has been defined for any period during which various regions appear to indicate climate anomalies that can be classified as being either ‘warm’, ‘wet’, or ‘dry’ relative to ‘20th century’ conditions. Such a criterion could be used to define any period of climate as ‘warm’ or ‘cold’, and thus cannot meaningfully characterize past large-scale surface temperature changes."

"(2) It is essential to distinguish (e.g. by compositing or otherwise assimilating different proxy information in a consistent manner—e.g., Jones et al., 1998; Mann et al., 1998, 1999; Briffa et al., 2001) between regional temperature changes and changes in global or hemispheric mean temperature. Specific periods of cold and warmth differ from region to region over the globe (see Jones and Mann, 2004), as changes in atmospheric circulation over time exhibit a wave-like character, ensuring that certain regions tend to warm (due, for example, to a southerly flow in the Northern Hemisphere winter mid-latitudes) when other regions cool (due to the corresponding northerly flow that must occur elsewhere). Truly representative estimates of global or hemispheric average temperature must therefore average temperature changes over a sufficiently large number of distinct regions to average out such offsetting regional changes. The specification of a warm period, therefore requires that warm anomalies in different regions should be truly synchronous and not merely required to occur within a very broad interval in time, such as AD 800-1300 (as in Soon et al, 2003; Soon and Baliunas, 2003)."

I didn't write that. The Real Climate-ologists are getting fed up with the disinformation that's being spread by the skeptical think-tanks, and they are now responding. With a very minimal effort you can probably figure out where I got the above quotes from.

[cogitator]

Out of sheer curiousity, where did you get the "250 annual rings" figure for the Lost Squadron? It was under more than 250 feet of ice and snow, but I've never seen any mention of varve counting in that area.

[Monti Cello]

So you are basing your claims on yet-to-be-published research you haven't seen, which will support a paper which has been debunked and 'beyond a shadow of a doubt', all while posting to an article which refutes your claims in the first place, and after accusing others of unscientific advocacy, and high-handedly warning others to prepare for a paradigm shift.

Your attitude and posting behavior on this topic hardly strikes me as balanced.

The paper right here speaks directly to the implications of the 'hockey stick' proposition, that current absolute temperature levels and the decadal rates of change are beyond natural variability. This paper demonstrates otherwise.

[cogitator]

She wasn't in a glacier. She landed inland. Do you know anything about it or are you just looking for an excuse.

"The airplanes landed near the shore of Greenland, where snow accumulation is rapid, about 2 meters per year. Allowing for some compaction due to the weight of the snow, that accounts for the depth of snow they are buried under. The planes are also on an active glacier and have moved about 2 km since landing. Ice core dating takes place on stable ice fields, not active glaciers. The interior of Greenland, where ice cores were taken, receives much less snow. In Antarctica, where ice cores dating back more than 100,000 years have been collected, the rate of snow accumulation is much less still."

Source: Glacier Girl

[cogitator]

So you are basing your claims on yet-to-be-published research you haven't seen, which will support a paper which has been debunked and 'beyond a shadow of a doubt', all while posting to an article which refutes your claims in the first place, and after accusing others of unscientific advocacy, and high-handedly warning others to prepare for a paradigm shift.

Claims that the paper (referring to only one of several papers by one group led by Dr. Michael Mann, and totally missing the fact that other millenial-scale climate reconstructions have been published showing the same climate patterns!) has been "debunked" are in error. The article that led off this thread doesn't refute the basic hockey stick pattern -- I posted an earlier response to it, which you might like to read. Basically it posits that there was a warm period in that region. The Southern Hemisphere's warmest period was 200 years later, when the Northern Hemisphere was entering the first stages of the "Little Ice Age".

As for the papers that are soon to be published, let's just wait until they're published, and then I'll put crow on the dinner menu. We can decide then who'll serve it and who's going to chow down.

[LexBaird]

We must stop all that stuff we're doing now and try to bring the planet back to the original size

Maybe if we all took out shovels and dug big holes, we could get the Earth back down to its old size.

[Monti Cello]

You are an advocate in this debate, while you deride others for such. How else am I to take your boast that you plan on serving up crow based on publications you have not even inspected? That is not a scientific or evenhanded approach. You have made your stand on this research before having seen it. Your posting on this topic is more consistent with someone on a personal mission, rather than someone who is interested in the truth wherever it leads. And your habit of trash-talking those who contradict you tends to undermine what points you may have.

[roaddog727]

Kick-the-greenies-in-the-pants Bump.

[Rebelbase]

"15 % all life dies"

Wrong. High concentrations of this cause all life to die.

[cogitator]

You are an advocate in this debate, while you deride others for such. How else am I to take your boast that you plan on serving up crow based on publications you have not even inspected? That is not a scientific or evenhanded approach. You have made your stand on this research before having seen it. Your posting on this topic is more consistent with someone on a personal mission, rather than someone who is interested in the truth wherever it leads. And your habit of trash-talking those who contradict you tends to undermine what points you may have.

You're not reading for comprehension, Monti. I base my arguments on what scientists are saying; what they say in print (preferably peer-reviewed), and what they say about what's in print (preferably peer-reviewed, but they are also commenting on material that's not peer-reviewed). "Advocacy" means twisting facts and statements to suit your argument. It means truncating quotes so that they seem to say something different than what they actually said; it means shading the meaning, "spinning", etc., whatever you may call it. It mainly means trying to influence opinion.

Whether or not you know it, the site from which the article that originated the thread was obtained is an advocacy science site. They find a reference in the literature, and then interpret it as best they can to fit their opinion, which is approximately that anthtropogenic global warming is not a problem because the Earth may have been nearly this warm in the past. This ignores questions of rate, scale, the types of climate forcings causing the warming, etc.

When I try to counter such arguments from a scientific viewpoint, I try to address that spin. I try as best possible to "serve up" the best scientific interpretation. If that's advocacy of good science, so be it.

Now, about reading for comprehension: based on what I've read, the content of the papers will do what I suggest it will -- which is, support the "hockey stick" depiction of accelerated, likely anthropogenically-forced (at least partially) warming in the late 20th and early 21st century, as compared to climate trends over the past 1000 years. The way I stated it left the option open that I could be wrong. I'm reasonably confident that I won't be -- but if shown to be so, I'll be the one dining with gustatory relish on sauteed crow. There is actually great delight in being shown to be conclusively wrong, because then one's intellect has made distinct gains in knowledge, even if it causes the ego to be diminished.

So -- watch the journals. And then we can decide. OK?

[JeffersonRepublic.com]

Compiled by R.S. Bradley and J.A. Eddy based on J.T. Houghton et al., Climate Change: The IPCC Assessment, Cambridge University Press, Cambridge, 1990 and published in EarthQuest, vo. 1, 1991. Courtesy of Thomas Crowley, Remembrance of Things Past: Greenhouse Lessons from the Geologic Record

1. The idea that man-made pollution is responsible for global warming is not supported by historical fact. The period known as the Holocene Maximum is a good example-- so-named because it was the hottest period in human history. The interesting thing is this period occurred approximately 7500 to 4000 years B.P. (before present)-- long before human's invented industrial pollution.

 

(view full-size image) Figure 1

2. CO2 in our atmosphere has been increasing steadily for the last 18,000 years-- long before humans invented smokestacks ( Figure 1). Unless you count campfires and intestinal gas, man played no role in the pre-industrial increases. As illustrated in this chart of Ice Core data from the Soviet Station Vostok in Antarctica, CO2 concentrations in earth's atmosphere move with temperature. Both temperatures and CO2 have been steadily increasing for 18,000 years. Ignoring these 18,000 years of data "global warming activists" contend recent increases in atmospheric CO2 are unnatural and are the result of only 200 years or so of human pollution causing a runaway greenhouse effect. Incidentally, earth's temperature and CO2 levels today have reached levels similar to a previous interglacial cycle of 120,000 - 140,000 years ago. From beginning to end this cycle lasted about 20,000 years. This is known as the Eemian Interglacial Period and the earth returned to a full-fledged ice age immediately afterward.

 

view full-size image Figure 2

3. Total human contributions to greenhouse gases account for only about 0.28% of the "greenhouse effect" (Figure 2). Anthropogenic (man-made) carbon dioxide (CO2) comprises about 0.117% of this total, and man-made sources of other gases ( methane, nitrous oxide (NOX), other misc. gases) contributes another 0.163% . Approximately 99.72% of the "greenhouse effect" is due to natural causes -- mostly water vapor and traces of other gases, which we can do nothing at all about. Eliminating human activity altogether would have little impact on climate change.

 

view full-size image Figure 3

4. If global warming is caused by CO2 in the atmosphere then does CO2 also cause increased sun activity too? This chart adapted after Nigel Calder (6) illustrates that variations in sun activity are generally proportional to both variations in atmospheric CO2 and atmospheric temperature (Figure 3). Put another way, rising Earth temperatures and increasing CO2 may be "effects" and our own sun the "cause".

[Always Right]

My friend, you're wrong -- the IPCC is not the be-all and end-all of climate science. But as for the hockey stick, I have on very good authority that in two papers -- one about to be published, one likely to be published later in 2005, the "hockey stick" will be verified beyond any shadow of any doubt.

How can something be proven beyond a shadow of a doubt when the preponderance of the evidence says otherwise. I have no doubt that they will make that claim, but please those are the same people have been saying for over a decade on the basis of a correlation say that it has been absolutely proven that global warming is entirely caused by man. Call me skeptical, but I know better than to accept their conclusions. There is just way too much evidence that shows there was a medevil warm period around most of the globe.

[Monti Cello]

My, how fast we went from:

the "hockey stick" will be verified beyond any shadow of any doubt. Sorry to be the one to break the news to you on that, but that's the way it's going to be. I recommend planning your own personal paradigm shift soon.

to:

So -- watch the journals. And then we can decide. OK?

That's all I was asking.

[FreeReign]

Bump for later.