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A 1240-Year Record of Arctic Temperatures
Center for the Study of Carbon Dioxide and Global Change ^

Posted on 12/17/2004 2:27:50 AM PST by Exton1

A 1240-Year Record of Arctic Temperatures


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


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


TOPICS: Extended News; News/Current Events
KEYWORDS: antarctic; artic; climatechange; eskimos; globalwarming; globalwarminghoax; hoax
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To: Exton1

In other words, any 'global warming' evidence thus far presented is within this range andf therefroe NO MEANINGFUL CONCLUSION can be drawn.

End of science lesson.


61 posted on 12/17/2004 11:59:50 AM PST by Mr. K ((this space for rent))
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To: larrye2001; KeyWest
"at 15% all life dies"


That's funny, as a Respiratory Therapist I routinely do high altitude testing on pulmonary patients using a gas mixture containing 15% O2 to simulate an airplane pressurized to 8000 ft. I'll have to tell them they're all dead next time I see them!
62 posted on 12/17/2004 12:05:16 PM PST by gc4nra ( this tag line protected by Kimber and the First Amendment (I voted for McClintock))
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To: Wonder Warthog
Ah, yet more research that shows that the "Medieval Climate Optimum" period was indeed global, and not an "anomaly confined to Western Europe (or the Northern Hemisphere)" as the "global warmers" are so fond of claiming.

First of all, I think you're mixing up two terms. There was a "Holocene Climate Optimum" -- the period you're referring to is most commonly called the "Medieval Warm Period" or MWP.

Can you show provide references that indicate the MWP was truly global? The main problem is that there is so little data from the Southern Hemisphere.

By the way, Baffin Island is in the Northern Hemisphere.

For a bit of help, there is decent data showing that the cold period from 1400 - ~1850 was global, but most intense in Europe and the northern Atlantic region. Is that what you're thinking of?

You also might like to read this:

Climate in Medieval Time (PDF)

Excerpt of interest:

"There is evidence for widespread hydrological anomalies from 900 to 1300 A.D. Prolonged droughts affected many parts of the western United States (especially eastern California and the western Great Basin) (14). Other parts of the world also experienced persistent hydrological anomalies (15). For this reason, Stine (14) argues that a better term for this period is the Medieval Climatic Anomaly, removing the emphasis on temperature as its defining characteristic."

In the single figure in this reference, the Baffin Island record is #15, indicating that the warmest 30 year period in that record occurred about A.D. 1200. In the figure, records 4-6 are Southern Hemisphere, showing the warmest 30-year period between 1400-1500 -- which in Europe was the start of the Little Ice Age!

63 posted on 12/17/2004 12:16:39 PM PST by cogitator
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To: AFPhys

See reply 63 for your edification.


64 posted on 12/17/2004 12:17:59 PM PST by cogitator
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To: larrye2001

No, I didn't, because it's not true.


65 posted on 12/17/2004 12:31:40 PM PST by Sofa King (MY rights are not subject to YOUR approval.)
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To: cogitator

As I said, "the globalwarmingwhackos have steadfastly maintained that the Medieval Warming was not world wide is that the Science showing the warming there is Absolutely Irrefutable. When someone devises an equally good way of establishing that it was, in fact, worldwide, they'll figure out some other way to lie and obfuscate to their moronic target masses. I've yet to hear any of their vaunted "models" demonstrate any possible methodology for maintaining a warm Arctic for centuries without other major climactic ramifications, but their "faith" allows them to simply 'know' that earth is warmer now than ever before - because man's activities 'clearly' makes it that way."

Keep up your faith mission.


66 posted on 12/17/2004 1:18:00 PM PST by AFPhys ((.Praying for President Bush, our troops, their families, and all my American neighbors..))
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To: AFPhys
I prefer to continue thinking. When you approach issues of science in scientific manner, you can never be wedded or welded to a single position, because new data or new interpretations can force substantial modification of what is "known".

On the other hand, when issues of science are approached in the manner of advocacy, it's hard to change a viewpoint, because the holders of the viewpoint are ideologically bound to the way that they think things should be -- not necessarily the way that things actually are.

67 posted on 12/17/2004 3:25:41 PM PST by cogitator
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To: Always Right

Noooo, now wait a second this could be series, if it's lower in cities it would explain the large urban vote for Kerry; they're not brain dead, only oxygen deprived.


68 posted on 12/17/2004 3:35:58 PM PST by Proud_texan
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To: Right Wing Assault; larrye2001
What size WAS the earth, BTW?
The same size as his brain.
69 posted on 12/17/2004 3:43:10 PM PST by oh8eleven
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To: Mr. K

ping


70 posted on 12/17/2004 4:27:30 PM PST by Exton1
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To: Exton1

bump


71 posted on 12/17/2004 4:32:21 PM PST by VOA
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To: Exton1

bump


72 posted on 12/17/2004 4:32:35 PM PST by VOA
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To: cogitator
"First of all, I think you're mixing up two terms. There was a "Holocene Climate Optimum" -- the period you're referring to is most commonly called the "Medieval Warm Period" or MWP."

Yeah, you're right. Brain-fart on my part.

"Can you show provide references that indicate the MWP was truly global? The main problem is that there is so little data from the Southern Hemisphere."

No--I'm past the point of keeping references on this stuff--got other stuff to keep me busy. I just keep seeing different studies from widely separated geographic areas all pointing to the "globalality" of the "Medievel Warm Period". One I "do" recall was from Australia. Used proxy oxygen isotope measurements on some shellfish in sediment.

73 posted on 12/17/2004 4:58:06 PM PST by Wonder Warthog (The Hog of Steel)
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To: Wonder Warthog; AFPhys; cogitator; All
Here's a link that mentions New Zealand, Australia, California, Argentina, Chile, Southern Peru as well as Southern Africa were all warmer during the MWP. All peer reviewed too.

Revising 1,000 Years of Climate History.

74 posted on 12/17/2004 5:58:36 PM PST by PeaceBeWithYou (De Oppresso Liber! (50 million and counting in Afganistan and Iraq))
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Related link.

SOIL GENESIS RELATED TO MEDIEVAL WARM PERIOD'S CLIMATIC FLUCTUATIONS IN SOUTHERN PATAGONIA AND TIERRA DEL FUEGO (ARGENTINA). CHRONOLOGICAL AND PALEOCLIMATIC CONSIDERATIONS

This one is a UNCPBA/GSA report.

75 posted on 12/17/2004 6:18:49 PM PST by PeaceBeWithYou (De Oppresso Liber! (50 million and counting in Afganistan and Iraq))
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To: Havoc

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


76 posted on 12/17/2004 6:25:17 PM PST by redangus
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To: Exton1

Fascinating Bump.


77 posted on 12/17/2004 6:31:07 PM PST by Nowhere Man (We have enough youth, how about a Fountain of Smart?)
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To: PeaceBeWithYou

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


78 posted on 12/17/2004 6:34:27 PM PST by Always Right
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To: redangus
Actually lake sediments and ice cores are very accurate at determining climatic conditions at the time the layer was put down.

Or so you say. The lost squadron crash landed during WWII.. By the time it was relocated, it was necessary to tunnel down to the planes which after 50 years were buried in 250 feet of ice and snow pack with more than 250 "annual rings". Accurate my eye. By practice and dead brained assumptions, we'd have to tell the world everyone was mistaken, WWII actually happened more than 200 years in the past beyond what is recorded in history books. You'll excuse me if I have problems with the subject or the claimed result.

79 posted on 12/17/2004 7:47:11 PM PST by Havoc (Reagan was right and so was McKinley. Down with free trade.)
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To: Havoc
...and they named her Glacier Gal.

Ice cores for dating, are taken in stable ice, not in or near a glacier.

80 posted on 12/17/2004 11:03:57 PM PST by PeaceBeWithYou (De Oppresso Liber! (50 million and counting in Afganistan and Iraq))
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