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A Global Temperature History of the Past Two Millennia [PEER-REVIEWED!!! WITH SOURCE!!!]
Energy and Environment 18: 1049-1058. ^ | November 2007 | Loehle, C., and J.H. McCulloch

Posted on 01/29/2008 11:13:13 AM PST by E. Pluribus Unum

Download original article here.

A Global Temperature History of the Past Two Millennia


Reference
Loehle, C. 2007. A 2000-year global temperature reconstruction based on non-treering proxies. Energy and Environment 18: 1049-1058.

What was done
Using data from eighteen 2000-year-long proxy temperature series from all around the world that were not developed from tree-ring data (which provide significant interpretive challenges), the author (1) smoothed the data in each series with a 30-year running mean, (2) converted the results thereby obtained to anomalies by subtracting the mean of each series from each member of that series, and then (3) derived the final mean temperature anomaly history defined by the eighteen data sets by a simple averaging of the individual anomaly series, a procedure that he rightfully emphasizes is "transparent and simple."

What was learned
The results obtained by this procedure are depicted in the figure below, where it can be seen, in the words of its creator, that "the mean series shows the Medieval Warm Period (MWP) and Little Ice Age (LIA) quite clearly, with the MWP being approximately 0.3°C warmer than 20th century values."


Mean relative temperature history of the globe. Adapted from Loehle (2007).

What it means
Loehle notes that "the 1995-year reconstruction shown here does not match the famous hockey stick shape," which clearly suggests that one of them is a poorer, and the other a better, representation of the truth. Because of its simplicity and transparency, as well as a host of other reasons described in detail by Loehle -- plus what we have learned since initiating our Medieval Warm Period Record-of-the Week feature -- it is our belief that Loehle's curve is by far the superior of the two in terms of the degree to which it likely approximates the truth.

Reviewed 30 January 2008


TOPICS: Business/Economy; Culture/Society; News/Current Events; Politics/Elections
KEYWORDS: agw; globalwarming
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Bottom Line: There have been two periods during the past 2000 years that were warmer than today.

The AGW propononents use a single temperature proxy, tree-rings, to predict global catastrophe.

This article uses the average of 18 temperature proxies for the past two-thousand years.

This is definitive data, folks.

Any time an enviro-wacko calls you a global-warming denier, wave this article in their face and ask them to refute it.

If there isn't any global warming, there isn't any anthropogenic component either.

1 posted on 01/29/2008 11:13:13 AM PST by E. Pluribus Unum
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To: E. Pluribus Unum

bump for ammo.


2 posted on 01/29/2008 11:15:25 AM PST by WhistlingPastTheGraveyard (John McCain: Bush Derangement Syndrome's "Patient Zero")
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To: E. Pluribus Unum
This just proves it - when the 9th-century folks quit buying gas-guzzling cars, the earth got cooler.

Coincidence? I think not.

3 posted on 01/29/2008 11:16:47 AM PST by Izzy Dunne (Hello, I'm a TAGLINE virus. Please help me spread by copying me into YOUR tag line.)
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To: Izzy Dunne

bump


4 posted on 01/29/2008 11:18:07 AM PST by JPJones
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To: M. Dodge Thomas
What is your opinion of this peer-reviewed article?
5 posted on 01/29/2008 11:18:36 AM PST by E. Pluribus Unum (Islam is a religion of peace, and Muslims reserve the right to kill anyone who says otherwise.)
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To: xcamel

POGW Ping.


6 posted on 01/29/2008 11:19:23 AM PST by DuncanWaring (The Lord uses the good ones; the bad ones use the Lord.)
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To: Izzy Dunne

I’ll bet that their sacrifice quota shot way up. And rightly so.


7 posted on 01/29/2008 11:19:59 AM PST by gathersnomoss (General George Patton had it right.)
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To: E. Pluribus Unum

8 posted on 01/29/2008 11:20:27 AM PST by Mr. Brightside
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To: E. Pluribus Unum; Fred Nerks

Thanks. Well Done.

I downloaded the article immediately.


9 posted on 01/29/2008 11:21:10 AM PST by Candor7 (Fascism? All it takes is for good men to say nothing.)
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To: Mr. Brightside
Thanks!

I didn't notice it was missing.

10 posted on 01/29/2008 11:21:50 AM PST by E. Pluribus Unum (Islam is a religion of peace, and Muslims reserve the right to kill anyone who says otherwise.)
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To: Mr. Brightside

Too bad they can’t get sunspots data going back that far, or can they?


11 posted on 01/29/2008 11:22:05 AM PST by RightWhale (oil--the world currency)
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To: E. Pluribus Unum; Killing Time; Beowulf; Mr. Peabody; RW_Whacko; honolulugal; SideoutFred; ...


FReepmail me to get on or off
Click on POGW graphic for full GW rundown
Dr. John Ray's
GREENIE WATCH


Really good work!!
12 posted on 01/29/2008 11:26:42 AM PST by xcamel (Two-hand-voting now in play - One on lever, other holding nose.)
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To: RightWhale

Boomp.


13 posted on 01/29/2008 11:29:23 AM PST by SaxxonWoods (If you don't vote, you don't matter.)
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To: All
But, but this author is in bed with the oil companies and is being paid for manipulating the data. /sarc off
14 posted on 01/29/2008 11:31:38 AM PST by halo66
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To: E. Pluribus Unum

Gadzooks. The author used creditable data, processed it in a meaningful way, did not throw away “inconvenient” data, and presented the results in a clear and understandable way. He’ll never be reported in the NYT.


15 posted on 01/29/2008 11:34:36 AM PST by Da Coyote
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To: Da Coyote
Gadzooks. The author used creditable data, processed it in a meaningful way, did not throw away “inconvenient” data, and presented the results in a clear and understandable way.

Must be a witch. Burn him!

16 posted on 01/29/2008 11:40:01 AM PST by Ditto (Global Warming: The 21st Century's Snake Oil)
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To: Filo

self bump


17 posted on 01/29/2008 11:40:38 AM PST by Filo (Darwin was right!)
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To: E. Pluribus Unum

The graph helps. I am at work, so I have to scan articles.


18 posted on 01/29/2008 11:40:39 AM PST by Mr. Brightside
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To: E. Pluribus Unum

Was that John McCain I heard today pledging to be green and to do something about greenhouse gases?


19 posted on 01/29/2008 11:43:41 AM PST by RogerFGay
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To: Ditto

Gorey be to Al !

A HERETIC !! A HERETIC !!

A HERETIC PRESENTING AN INCONVENIENT TRUTH !!

Let him be subjected to le pein forte et dure !!


20 posted on 01/29/2008 11:44:14 AM PST by genefromjersey (So much to flame;so little time !)
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To: E. Pluribus Unum

So you know and I know, but how do we get past the steel bars of the MSM cage and get the message public? What to use as a hacksaw so to speak?

I’ll pass this on to many, but that is a few only, and many of those folks will look at this, their eyes will glaze over, and the delete button will serve its purpose.


21 posted on 01/29/2008 11:44:56 AM PST by rockinqsranch (Dems, Libs, Socialists...call 'em what you will...They ALL have fairies livin' in their trees.)
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To: E. Pluribus Unum
Any time an enviro-wacko calls you a global-warming denier, wave this article in their face and ask them to refute it.

But what about the shrinking Polar bear testicles?

22 posted on 01/29/2008 11:47:33 AM PST by John123 ("What good fortune for the governments that the people do not think" -- Adolf Hitler)
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To: Ditto
Must be a witch. Burn him!

Don’t be silly that is no longer acceptable per PC rules. We must tie a stone to him and through him in a pond.

23 posted on 01/29/2008 11:51:29 AM PST by usurper (Spelling or grammatical errors in this post can be attributed to the LA City School System)
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To: E. Pluribus Unum

This is the key statement near the end which allows both that previous data still need to be compared to the authors’ methods and that this study, like all scientific studies that are not biased by agenda, are merely signposts on a roadmap that will lead to the true destination.

“While instrumental data are not strictly comparable, the rise in
29 year-smoothed global data from NASA GISS (http://data.giss.nasa.gov/gistemp)
from 1935 to 1992 (with data from 1978 to 2006) is 0.34 Deg C. Even adding this rise
to the 1935 reconstructed value, the MWP peak remains 0.07 Deg C above the end of
the 20th Century values, though the difference is not significant.
The main significance of the results here is not the details of every wiggle, which
are probably not reliable, but the overall picture of the 2000 year pattern showing the
MWP and LIA timing and curve shapes. Future studies need to acquire more and
better data to refine this picture.”


24 posted on 01/29/2008 12:00:56 PM PST by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: RightWhale
Well, 1610 is supposedly when astronomers started recording sunspot activity from direct observation.

Chinese records of sunspot activity go back to around 800 BC, although spotty (no pun intended) and incomplete. But according to another article, tree rings have also recorded sunspot activity and can be used to track them back to the last ice age.

Sunspots leave telltale marks in trees

Trees and tree rings contain carbon, which they get from carbon dioxide in the atmosphere. Some of that carbon is the isotope carbon-14, which is created in the Earth's atmosphere by cosmic rays flying in from outside the solar system.

But those cosmic rays can't reach Earth when the Sun is stormy with sunspots and the solar wind is roaring. So a tree ring containing low carbon-14 is a sign of few cosmic rays in that growth year. This is an indicator of a stormy Sun, said researchers led by Professor Sami Solanki from the Max-Planck Institute for Solar System Research and colleagues.


25 posted on 01/29/2008 12:01:05 PM PST by AFreeBird (No Romney, No Rudy, No McLame, No Huck, No Paul! Toss the GOP into the ashcan of History.)
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To: E. Pluribus Unum; cogitator

cogitator needs to add this to his archive.


26 posted on 01/29/2008 12:04:32 PM PST by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: Ditto
Must be a witch. Burn him!

Not necessarily. Does he weigh the same as a duck?

27 posted on 01/29/2008 12:05:14 PM PST by AndyTheBear (Disastrous social experimentation is the opiate of elitist snobs.)
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To: Ditto

Who knew you were so wise in the ways of science!


28 posted on 01/29/2008 12:08:49 PM PST by pierrem15 (Charles Martel: past and future of France)
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To: AFreeBird
Trees and tree rings contain carbon, which they get from carbon dioxide in the atmosphere. Some of that carbon...

Oh good grief. Something has got to give about what "scientists" are willing to conclude from tree ring data. How can we put these presumptions to the test? Could not the carbon have been high for some other reason?

29 posted on 01/29/2008 12:13:33 PM PST by AndyTheBear (Disastrous social experimentation is the opiate of elitist snobs.)
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To: E. Pluribus Unum

TO READ LATER, THX


30 posted on 01/29/2008 12:13:33 PM PST by enduserindy (Living in Indy just got better! Ah Colts! Hi Mom! Vote for America! (I had to do it!))
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To: E. Pluribus Unum

bttt


31 posted on 01/29/2008 12:15:11 PM PST by ELS (Vivat Benedictus XVI!)
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To: E. Pluribus Unum


Excellent.

32 posted on 01/29/2008 12:16:14 PM PST by Constitutionalist Conservative (Global Warming Heretic -- http://agw-heretic.blogspot.com)
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To: pierrem15
Who knew you were so wise in the ways of science!

Science used to be hard. Now, thanks to Al Gore, and the IPCC, it's really easy. Just decide how much you want to raise taxes, enter that number into the patented Climate Change Computer model, and volia, multiple climate horror stories guaranteed to open the wallet of even the tightest skin flint. No more late nights in the lab. No more pesky peer review. The Global Climate Change Computer does it all for you.

33 posted on 01/29/2008 12:23:50 PM PST by Ditto (Global Warming: The 21st Century's Snake Oil)
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To: AndyTheBear
Sure, we could have been hit by a particularly bad cosmic storm, but I suspect that could also be gleaned from the data. And I'm not suggesting that tree data is the Holy Grail, as the posted article attests.

But the more data (as long as it is properly analyzed and reviewed), the clearer the overall picture.

34 posted on 01/29/2008 12:26:30 PM PST by AFreeBird (No Romney, No Rudy, No McLame, No Huck, No Paul! Toss the GOP into the ashcan of History.)
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To: E. Pluribus Unum
What is your opinion of this peer-reviewed article? http://www.realclimate.org/index.php/archives/2007/12/past-reconstructions/#more-506
35 posted on 01/29/2008 12:27:29 PM PST by M. Dodge Thomas (Opinion based on research by an eyewear firm, which surveyed 100 members of a speed dating club.)
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To: Old Professer
Future studies need to acquire more and better data to refine this picture.”

Hogwash.

The scientific consensus is already in.

No further data is required.

Carbon-credit brokers, start your money-churns!

36 posted on 01/29/2008 12:29:23 PM PST by E. Pluribus Unum (Islam is a religion of peace, and Muslims reserve the right to kill anyone who says otherwise.)
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To: AndyTheBear
Could not the carbon have been high for some other reason?

CO2 is plant food. It's where trees get pretty much all their carbon from. Think back to your high-school biology class, where you learned that aside from a few trace nutrients all a plant needs is water and air to grow.

37 posted on 01/29/2008 12:30:59 PM PST by ctdonath2 (GWB wept for those who suffer. HRC wept for herself.)
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To: M. Dodge Thomas
The Loehle paper was published in Energy and Environment - a journal notable only for its rather dubious track record of publishing contrarian musings. The reconstruction itself is based on a network of 18 records that are purportedly local temperature proxies, and we will use those as examples in the points below. More discussion of this paper is available here.

Sounds like an ad hominem attack, to me.

So Mann's hockey stick is still the gospel according to Algore, eh?

38 posted on 01/29/2008 12:34:44 PM PST by E. Pluribus Unum (Islam is a religion of peace, and Muslims reserve the right to kill anyone who says otherwise.)
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To: ctdonath2
CO2 is plant food...

Yep, sure is. But I'm not sure what your point is, or maybe you didn't get what mine was.

39 posted on 01/29/2008 12:50:06 PM PST by AndyTheBear (Disastrous social experimentation is the opiate of elitist snobs.)
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To: ctdonath2

Hydroponics

http://www.a1b2c3.com/drugs/mjgrow10a.htm


40 posted on 01/29/2008 12:52:33 PM PST by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: E. Pluribus Unum

The National Science Foundation investigaterd the Algore version of history (which emasculates the little ice age), and said it is not inconsistent with the data. This is not an affirmation. This is a statement that the UN was in the no man’s land between science and fraud. The NAtional Science Foundation then adopted something like this version of history (with the little ice), and the clear implication that we are currently in a not unusual warming phase in the hsitory of the world. As to whether human activity is ADDING TO this warming phase remains a legitimate question.


41 posted on 01/29/2008 12:57:05 PM PST by Redmen4ever
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To: E. Pluribus Unum

Looks like an oscillation with around a 1300 year cycle. What with data we’re seeing about variations in solar output, I’m thinking there may be more coming from solar output oscillation than any human cause


42 posted on 01/29/2008 1:03:34 PM PST by PapaBear3625
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To: Old Professer; E. Pluribus Unum
Yes, thanks, I got it. I will first note that the author (Loehle) appears to have done a very good job.

First impressions: Looking at the map of locations, it says there are 18 series, but I only count 15. There are likely more than one series from a couple of locations. Based on what I can see, 7 out of the 15 are extra-tropical in either North America, the North Atlantic, or Europe. So this area is over-represented and the Northern Hemisphere is over-represented.

Why is this important? Because previous work on the Medieval Warm Period has indicated that it was primarily a Northern Hemisphere event strongest in North America and Europe. (The LIA was more global.) So seeing it (a warming event occurring over about 400 years) in this data is not surprising.

2. Got this from Climate Audit, actually (which is instructive, 320 comments in the "Loehle Correction" thread). His last actual data point is 1935 (which is where his corrected Figure 2 ends). If you read the last paragraph of the correction, the difference between MWP and "end of 20th century values" is not significant. He calculated end-of-20th-century using a GISTEMP addendum, it appears.

3. What is significant? The warming rate. Reading Figure 1 roughly, the temperature increase is about 0.6 C in 400 years (I put the peak at about 900 AD). The warming rate in the 20th century was 0.6 C in 100 years, and the rate in the past 25 years was 0.4 C, which is 1.6 C in 100 years. So while comparing peak temperatures is a fun exercise, the rate of warming observed since 1900 is much faster than the rate of warming to the peak of the MWP.

Intriguing pattern: there is a big up and down temperature excursion right after 900 AD. I'd really like to see if that has a global signature or if it was regional.

Comments on "Loehle Correction" (Climate Audit)

Skimming, I note posts 16, 69 (Loehle is skeptical of rates, so I should be too), 95, 199, 203, and 301.

43 posted on 01/29/2008 1:12:23 PM PST by cogitator
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To: E. Pluribus Unum

Ping


44 posted on 01/29/2008 1:20:49 PM PST by Thickman (Term limits are the answer.)
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To: cogitator

“Why is this important? Because previous work on the Medieval Warm Period has indicated that it was primarily a Northern Hemisphere event strongest in North America and Europe. (The LIA was more global.) So seeing it (a warming event occurring over about 400 years) in this data is not surprising.”

Current temperature models are primarily based on North American readings (most pervasive and “accurate”). Then there is the apples to oranges aspect to your retort - that being modern sampling techniques versus historical climate reconstruction. Consequently, the only possible comparisons are the peaks and valleys.

I’m calling BcoughULLcoughcoughSHcoughIcoughT.


45 posted on 01/29/2008 1:28:25 PM PST by Thickman (Term limits are the answer.)
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To: cogitator

I think we’re kind of stuck with mostly northern hemisphere data since there aren’t many good sampling locations down under.

The rate of increases are notable just because of their lack of periodicity yet the graphs show that each period of cooling began nearly precipitously which might make one question what shut off the cause of warming so suddenly.


46 posted on 01/29/2008 1:42:51 PM PST by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: xcamel

Thanks for the ping!


47 posted on 01/29/2008 2:02:35 PM PST by alwaysconservative (If it's consensus, it's not science. If it's science, it doesn't require a consensus...Crichton)
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To: E. Pluribus Unum

INTERESTING!!!!

E-mail to Gore.


48 posted on 01/29/2008 2:03:20 PM PST by ZULU (Non nobis, non nobis Domine, sed nomini tuo da gloriam. God, guts and guns made America great.)
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To: Izzy Dunne

They had to change out their light bulbs too.......


49 posted on 01/29/2008 2:19:41 PM PST by CIDKauf (No man has a good enough memory to be a successful liar.)
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To: Ditto

We need too waterboard Al and get the real inconvenient truth.........


50 posted on 01/29/2008 2:23:50 PM PST by CIDKauf (No man has a good enough memory to be a successful liar.)
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