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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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To: Beowulf; Defendingliberty; WL-law; Normandy

Beam me to Planet Gore !

61 posted on 01/29/2008 4:01:25 PM PST by steelyourfaith
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To: cogitator

It will be interesting if research continues to find some variable that accounts for the oscillations and resolves some of the contentions that seem to be driven by political expediency.


62 posted on 01/29/2008 5:47:04 PM PST by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: M. Dodge Thomas
...but none of that changes the fact that to make AGW go away as an explanation for last 200 years of global warming you have to find some way to falsify the basic physics and chemistry of greenhouse effects.

200 years ? So I take it now that we are considering the Steam Engine as a significant AGW factor ?

63 posted on 01/29/2008 5:48:46 PM PST by justa-hairyape
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To: E. Pluribus Unum

Well, get your head around it: it’s not only AGW, it’s acid ran from coal fired generators in China and ocean-dumped mercury form South America, and CO2 from Indian cars.

We’ve sort of conditioned ourselves to deplore any sort of controls on such activity because heretofore we have been the primary beneficiaries of evading full accounting for such externalities.

From this point forward however, we well be increasingly on the receiving end of the externalities, but without any of the economic gains accruing to the countries producing them.

And somehow we are going to have to negotiate some sort of international arrangements to share the pain of reducing everyone’s aspirations to archive dependence on a type of economy and carbon based energy regime that’s simply unsupportable as increasing numbers of people attempt to emulate it.

Unfortunately, “Dems da’ facts” of the basic environmental science.

And the politics of working through them - both domestically and internationally - are going to be *very* contentious.


64 posted on 01/29/2008 6:16:54 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: Ditto

How do you know he’s a witch?


65 posted on 01/29/2008 6:20:56 PM PST by shankbear (Al-Qaeda grew while Monica blew)
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To: justa-hairyape
200 years ? So I take it now that we are considering the Steam Engine as a significant AGW factor ?

1800 forward is roughly the point at which industrial economies first began to produce significant quantities of CO2 and other GHGs to the atmosphere. And yes, the increasing use of coal - largely for the production of steam power - was one of the first major industrial contributions. It took about 50 years forward from that point for things to really take off.


66 posted on 01/29/2008 6:34:41 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: RightWhale
Records of naked-eye sunspot observations in China go back to at least 28 BCE.
67 posted on 01/29/2008 6:40:05 PM PST by aruanan
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Comment #68 Removed by Moderator

To: justa-hairyape

Sorry about the size of that image, but total hydrocarbon use occurring today makes the hydrocarbon use prior to 1900 stattiscally insignificant.


69 posted on 01/29/2008 6:45:27 PM PST by justa-hairyape
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To: justa-hairyape

70 posted on 01/29/2008 7:52:59 PM PST by I got the rope
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To: justa-hairyape

Fixed it.


71 posted on 01/29/2008 7:53:45 PM PST by I got the rope
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To: I got the rope
And for the really intelligent people:

But hey, Al, his lawyers, and their crooked scientists got paid so who cares?

72 posted on 01/29/2008 8:08:07 PM PST by Justa (Politically Correct is morally wrong.)
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To: M. Dodge Thomas
So, CO2 drives the Climate. So you are putting your faith in a playstation GHG models?
Of course the GHG models, for the past 30 years, have never been peer-reviewed or validated!
CO2 induced global warming, rename to CO2 climate change, rename climate change is a scam.
I wonder how the GHG models will play out against the DATA QUALITY ACT.
73 posted on 01/29/2008 8:37:08 PM PST by steveab (When was the last time someone tried to sell you a CO2 induced climate control system for your home?)
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To: I got the rope

Thanks for the image fix. The belief that CO2 levels are the significant driving factor for global temperature trends also requires an explanation for why the temperatures fell during the 1950’s while CO2 levels were rising. From what I have read, their explanation involves aerosol and particulate pollutants that were released during that time frame. The belief that solar activity is the significant driving factor for global temperature trends requires no other qualification. It is the best fit. Just look at that chart. Solar activity was the leading factor determining arctic air temperature trends.


74 posted on 01/29/2008 8:49:09 PM PST by justa-hairyape
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To: RightWhale
Too bad they can’t get sunspots data going back that far, or can they?

There are isotope proxies for sunspots, and I believe they've been characterized and tabulated using ice core data.

75 posted on 01/29/2008 8:51:57 PM PST by r9etb
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To: r9etb

76 posted on 01/29/2008 9:02:30 PM PST by jwalsh07
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To: E. Pluribus Unum

bookmark


77 posted on 01/29/2008 9:28:03 PM PST by FBD (My carbon footprint is bigger then yours)
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To: jwalsh07
Nice chart. I generally do not think that looking at temperature readings in Arctic Polar regions gives a good REAL TIME trend evaluation. Primarily because there is probably a significant delay between equatorial (tropical/subtropical) solar flux levels and the resulting air and water temperature in the polar regions. Mid Latitudes are probably more accurate in determining current trends. However, the problem with mid-latitudes and equatorital regions are that temperature sensors in those areas tend to be located within urban heat areas. Historically preserved readings from the Arctic should theoretically be less affected by urban heat island affects.

Concerning the future sunspot activity, NASA is predicting that Solar Cycle 25 (cycle 24 is just starting) will be a very weak cycle based on measured plasma belt current velocities. So 2020-2033 should see very low solar activity. Ironically, solar cycle 24 looks to also be starting late and weak. Coincidently we just had a cold winter in the Southern Hemisphere and in many areas of the Northern Hemisphere this currently looks to be a cold winter. I am living in the Los Angeles area but the weather here has been what Seattle normally experiences. China right now is trying to keep people warm and is running low on mined coal.

78 posted on 01/29/2008 11:30:42 PM PST by justa-hairyape
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To: M. Dodge Thomas
At least you admit that it's not really about science, it's about establishing a global non-democratic dictatorship run by out intellectual and genetic superiors.
79 posted on 01/30/2008 6:11:18 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: E. Pluribus Unum
At least you admit that it's not really about science, it's about establishing a global non-democratic dictatorship run by out intellectual and genetic superiors.

Why in the world would you assume that? IMO very clear is that this will be a political process, both internally within countries and in their negotiations with each other.

80 posted on 01/30/2008 6:28:47 AM 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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