IPCC changed viewpoint on the MWP in 2001 – did this have effect on scientific results?
Guest post by Frank Lansner Latest News (hidethedecline)
A brief check indicates a “warm MWP-consensus” before IPCC published the Mann hockey stick graph in 2001. But after 2001, results on MWP seems to approach the IPCC viewpoint.
In April 2009 I collected a series of results concerning Holocene, Historic and recent temperatures for an article on WattsUpWithThat.
Here I found approximately 54 datasets (almost 100% peer reviewed results) that I used for analyzing the claimed difference on MWP on the Northern vs. the Southern hemisphere. I also used the 54 datasets to see if the tree ring method has an impact on MWP results.
Another aspect of MWP results caught my interest:
fig. 1.
It is often debated how IPCC changed its viewpoint concerning the Medieval Warm Period in 2001.
– Was the pre-2001 MWP viewpoint simply “wrong” ?
– When IPCC launched their new viewpoint on MWP in 2001, was this new viewpoint in fact the consensus in 2001?
– Or did the IPCC actually claim to know better than the consensus in 2001?
– What is the consensus on the MWP today?
– And finally, did the results after IPCC change of viewpoint in 2001 have changed, how can this be explained?
Here are the 54 temperature datasets covering the MWP divided in two groups :
1) 1976-2000 vs 2) 2001-2009
fig. 2. (Geographical origin see)
First we see that both 1) and 2) shows the MWP was warmer than today. (This is partly due to my criteria for the 54 datasets: Max 15% tree ring data, due to possible problems with tree ring data and thus a need to see data not dominated by this one method. Quite a few of the excluded tree ring data are frequently used by the IPCC, yielding the well known hockey shapes from IPCC AR4, 2007.)
Second, we see a MWP for group 1) 1976-2000 more than twice as warm, compared to recent years, as the group 2) 2001-2009. A significant and surprising finding. The distance between 1) and the IPCC hockey sticks, with all the tree graphs of recent years, is even bigger.
One might argue that the data choice for my Watts article was not quantitative, fully exact, etc. But I simply cannot come up with any explanation for such a big change in the trend of results when just dividing by the year of publishing. Therefore I will assume that there is in fact a development in the results regarding the MWP after 2001.
Further, if you compare graph 1) 1976-2000 on fig. 2 with the original temperature graph IPCC 1990-2001 on fig.1., you will see a stunning match. This indicates that the consensus of a WARM middle age before year 2001 was likely to be a real consensus. If true:
How could the IPCC publish the hockey stick in 2001 and ignore the consensus at the time?
Several results came later that confirmed the IPCC’s 2001 Opinion: Hockey sticks, mainly tree lines. But how could the IPCC know what the future results on the MWP would be?
If the conclusions of “climate gate” are even remotely true, then this would explain that the IPCC controlled the future results.
I found this dated news release (June 22, 2006) from the National Academies, based on a report from the National Research Council.
“‘High Confidence’ That Planet Is Warmest in 400 Years;
Less Confidence in Temperature Reconstructions Prior to 1600”
http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=11676
What is rather curious is that going back 400 years from 2006 places the year at 1606, in the center of the Maunder Minimum. At first glance, it would appear that the NA is asceding that temperatures were warmer prior to 1606 than the present, but upon closer examination, this is found not to be the case; they are simply constraining the extent of the known cooler period to 400 years due to the uncertainty prior to 1600. In fig. 1 (Frank Lansner’s article), you have to regress to (approximately) the year 1300 to encounter temperatures warmer than the present. I interpret Fig. 1 as stating “Planet Is Warmest in 700 Years”.
The NA release also states “The exact timing of warm episodes in the medieval period may have varied by region, and the magnitude and geographical extent of the warmth is uncertain, the committee said. None of the reconstructions indicates that temperatures were warmer during medieval times than during the past few decades, the committee added.”
I’m not taking any personal position on the extent of the warming during the MWP, but wanted to point out the fact that both the NRC and NA acknowledge the existence of the MWP, while not placing a high confidence in the temperature reconstructions prior to the Maunder Minimum.
Contrast this with the headline article that appeared on cnn.com in July, 2006 (conveniently timed to coincide with the peak summer heat!), where they reproduced the Mann Hockey Stick graph, along with a photoshopped fireball earth, and stated the earth is now the warmest it has been in 2,000 years. It’s interesting that CNN ignored the NRC and NA positions on the temperature record, and instead promoted “Mann-Made Global Warming”. CNN has obviously taken this article down from their site, as I was unable to locate it with a search today.
Smokey (10:18:18) :
“It’s a damn poor mind that can only think of one way to spell a word.”
~President Andrew Jackson
That’s a brilliant quote. I’ve sent it on to my brother – he has a damn good mind.
Sometimes I believe entire armies of warmists want AGW (here to mean catastophic changes in climate due to human CO2 production) to be true. From a humanitarian and or humanistic point of view anyone should want it to be false yet innumerable fanatics keep defending alarmist projections based on inadequate evidence. Why on earth would the IPCC actors want AGW to be true? They should be doing their very best to falsify the thesis that there is something grave going on, not to assume and oracle prophecies that catastrophies are ahead. there may well be problems ahead but so far we haven’t got much of a clue.
Living in the Netherlands by all standards one of the smaller countries in Europe I see differences in temperatures of no less 10 degrees Celcius in different near see level locations at the same moment e.g. Groningen warmer or colder than Maastricht.
Bearing this in mind I am very sceptic about any historic temperature analysis on one tenth of a degree Celcius from any pre-thermometric era, all the more based on limited grid samples, in fact all pre-satelite data should be interpreted with care, which leaves us with which historic time span?.
By the way, really funny the way the IPCC reacted to the criticism to the impact paragraph: We may have been wrong about the impact and really we do not know if there is a real threat but we are certainly right about humans causing warming. If there is no threat then why bother?
Just to conclude that there is a lot to be learned and discovered still, both on how the climate works and most certainly on how international institutions work.
@Alexander Vissers (15:33:42) :
“By the way, really funny the way the IPCC reacted to the criticism to the impact paragraph: We may have been wrong about the impact and really we do not know if there is a real threat but we are certainly right about humans causing warming. If there is no threat then why bother?
Just to conclude that there is a lot to be learned and discovered still, both on how the climate works and most certainly on how international institutions work.”
– – – – – – – –
$$$$$$$!
According to Christopher Monckton, one of the early draft resolutions for COP-15 (Copenhagen) was that the UN would collect an annual “tribute” of 2% of GDP from each signing industrialized nation. From the USA alone, this would be approximately $285 billion per year (based on nominal GDP), which is approximately $930 per person per year for every man, woman and child living in the country. It would be “Oil for Food” all over again.
http://www.protectionist.net/2009/12/21/monckton-says-cop15-could-set-up-the-mechanism-for-a-world-government/
Dave Wendt:
I wouldn’t blame Whorf on Sapir.
The unofficial Theme Song of WUWT…
Richard Telford (13:30:43) :
I’m a historian. Science is not the only authority on the past, and the Medieval Warm Period is well attested in historical (archival) documents for Europe and Eastern North America (i.e Viking records) and was never controversial until the IPCC and its agenda came along. Scientific and archaeological evidence by non-climate scientists has tended to back up the historical evidence:
http://wattsupwiththat.com/2009/10/26/on-the-vikings-and-greenland/
including evidence from North America:
http://wattsupwiththat.com/2009/10/21/more-proof-of-the-medieval-warm-period-from-midges/
the Indo-Pacific (for which the Medieval Warm Period is widely credited by anthropologists for assisting the trans-Pacific travels and exploration of the Polynesians, which ended roughly when temperatures cooled)
http://wattsupwiththat.com/2009/09/02/woods-hole-embraces-the-medieval-warm-period-contradict-manns-proxy-data/
and South America:
http://wattsupwiththat.com/2009/07/08/the-medieval-warm-period-linked-to-the-success-of-machu-picchu-inca/
Chinese historians also vigorously defend the existence of the medieval warm period: see for example::
http://www.springerlink.com/content/gh98230822m7g01l/
( De’Er Zhang ‘Evidence for the existence of the medieval warm period in China’ in Climatic Change Vol. 26, Numbers 2-3 / March, 1994:
abstract: The collected documentary records of the cultivation of citrus trees andBoehmeria nivea (a perennial herb) have been used to produce distribution maps of these plants for the eighth, twelfth and thirteenth centuries A.D. The northern boundary of citrus and Boehmeria nivea cultivation in the thirteenth century lay to the north of the modern distribution. During the last 1000 years, the thirteenth-century boundary was the northernmost. This indicates that this was the warmest time in that period. On the basis of knowledge of the climatic conditions required for planting these species, it can be estimated that the annual mean temperature in south Henan Province in the thirteenth century was 0.9–1.0°C higher than at present. A new set of data for the latest snowfall date in Hangzhou from A.D. 1131 to 1264 indicates that this cannot be considered a cold period, as previously believed.)
Little Ice Age and Medieval Warm Periods in Eastern China as Read from the Speleothem Records
Li, H.; Ku, T.
American Geophysical Union, Fall Meeting 2002, abstract #PP71C-09 (The records show that in eastern China, the Medieval Warm Period started around 1000 AD and lasted until 1500 AD. A brief cooling during this warm interval occurred around 1150 AD.)
Zhang, Y., Z. C. Kong, S. Yan, Z. J. Yang, and J. Ni (2009), “Medieval Warm Period” on the northern slope of central Tianshan Mountains, Xinjiang, NW China, Geophys. Res. Lett., 36, L11702, doi:10.1029/2009GL037375.
Received 26 January 2009; accepted 22 April 2009; published 4 June 2009.
Other evidence for Asia:
Medieval climate warming and aridity as indicated by multiproxy evidence from the Kola Peninsula, Russia (Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 209, issues 1-4, pp. 113-125, 6 July 2004) – K. V. Kremenetski, T. Boettger, G. M. MacDonald, T. Vaschalova, L. Sulerzhitsky, A. Hiller
Global evidence:
ttp://wattsupwiththat.com/2009/11/29/the-medieval-warm-period-a-global-phenonmena-unprecedented-warming-or-unprecedented-data-manipulation/
JonesII (12:05:05) :
“… I insist: That global government is already working through all the binding agreements signed in the past by all governments ….. Let’s name them and describe them, one by one, and see how they work in your community, in your neighborhood.”
REPLY:
It would take years.
For example Clinton and Al Gore:
The World Trade Agreement http://www.publiceyeonscience.ch/images/the_wto_and_the_politics_of_gmo.doc
The President’s Council on Sustainablitiy -headed by Al Gore, divides the USA into 10 regions governed by NGOs. Federal funds go to these regions and bypass state governments thereby cutting out elected officials from the governing process.
Check and see if your town, city or county now has a “Land Use Plan” This is written by the NGOs, not voted on yet it determines what you are allowed to do on your private property. The UN name for this is Agenda 21.
“the Wildlands Project” legislation we in the USA squeaked out of by the skin of our teeth just before the vote. It was to set aside over one half of the USA as “core wilderness” were humans would be forbidden to go. Much of the rest of the area would only allow highly regulated activity leaving only small areas were the Us population would be herded into. http://www.propertyrightsresearch.org/articles2/wildlands_project_and_un_convent.htm
Veronica (England) (12:28:59) :
I can’t fathom out what this shows… your graph looks like a plateful of colourful spaghetti to me. As many lines above the recent data as below… where’s the trend?
I’m a simple biologist, I can’t follow this!
Reply:
This is proxy data from many different studies.and not direct measurements therefore the timeline is rather iffy in many cases. As some of the commenters have said these proxies need to be reality checked against written historical record before they are of use.
What Frank Lansner was doing was looking at ALL the studies before IPCC did away with the Medieval Warming Period vs ALL the studies after to see if the Mann hockey stick graph introduced a bias in the studies reported. He found that there was a definite bias indicating the IPCC’s agenda influenced the science that was reported.
Frank did not screen the studies by comparing them to the written historical record. His objective was not to determine the true temperature of the Medieval Warm period but to determine if politics was introducing a bias in the scientific studies published after the Mann hockey stick graph.
Hope that helps.
Kitefreak (12:46:49) :
“…Yes, indeed, all part of the psychological warfare. That’s why they employ people like Connelly.
That, along with (deliberate) dumbing down of the population in general, and using the threat of economic meltdown as the financial terrorists bankrupt nations, is how they will get their agenda through.
They bide their time. It is incremental. This to them is not a short term project (although the schedule has been very hectic recently).”
I have the feeling Obama was supposed to usher in “The CHANGE” there was a heck of a lot of pre-written legislation they tried to rush through congress at the beginning of 2009. Luckly a lot of it has stalled and the American public is showing signs of waking-up.
I understand a lot of those behind the scenes are getting old and want to see their vision of “Global Governance” in place before they die. I think they may have jumped the gun a bit.
In Sept. 14, 1994 David Rockefeller, speaking at the UN Business Council:
“This present window of opportunity, during which a truly peaceful and interdependent world order might be built, will not be open for too long – We are on the verge of a global transformation. All we need is the right major crisis and the nations will accept the New World Order.”
Richard Telford (13:30:43) :
“The MWP reconstruction in the IPCC AR2 was produced by HH Lamb for England, mainly from documentary evidence. Not withstanding the large areas of pink in every schoolboy’s atlas, England covers a rather small proportion of the earths surface. To claim this curve to represent the whole earth would be a gross extrapolation…..”
That has already been answered please look at this interactive map with all the MWP data (graphs) from various locations.
http://pages.science-skeptical.de/MWP/MedievalWarmPeriod.html
To all English majors:
‘”They’re going to disappear him,” she said.”
“”It doesn’t make sense. It isn’t even good grammar. What the hell does it mean when they disappear somebody?””
These are some lines from Chapter 34 of Joseph Heller’s “Catch-22”, published in 1955.
A truly great piece of literature in the English language. If you don’t know your English language, its usage, and history; don’t knock other’s usage.
http://www.csicop.org/si/show/mann_bites_dog_why_climategate_was_newsworthy/
See also David Morrison’s interview (not available online, apparently) in the latest print version, March-April of this year, on the most common Denialist claims, and why he feels they’ve all been batted down. Thus as some examples, the whole “carbon is WONDERFUL” shibbeloth (wrong, unless you can keep plants from warming up, which they don’t like as CO2 intake increases) and of course the whole mess about there not being a consensus.
Well…that’s not really the case. As Morrison points out, most of the critics have cherry picked data are neither climatologists nor honest about their findings. In point of fact it was this frustration with the facts on hand that led to chicanery such as email snitching. And what was found, in fact (yet another inconvenient one) ?
Not much, other than an allegation of stanched data and missing files that are easily found elsewhere in labs planetwide, and of yeah, the fact that real climatologists are people, they stomp and curse sometimes, and get mad at their ignorant detractors. In the thousands of emails, some very naughty language came out.
I think that about wraps it up.
lithophysa1 (18:27:36) re: Catch-22
Oh! Oh! I’ve read that book!!!!! Damned Army jeep. How many missions have you flown? And did you carry eggs with you?
Zoon:
“The attacks had become increasingly vile as the past decade, the hottest in human history, came to an end. ”
-Mark Boslough
I hope Mark’s physics is better than his history.
Interesting figures about the past climate of the northern hemisphere. The data is from a ice core at Greenland see:
http://www.ncdc.noaa.gov/paleo/metadata/noaa-icecore-2475.html
The figures are further down on:
http://www.foresight.org/nanodot/?p=3553
I guess there were warmer periods in the past. At least in the northern parts.
There is an analog here to the famous Millikan oil drop experiment. The community believed than the electron had a certain charge. Millikan developed a clever and effective method for deducing that charge. He ran his experiment and collected some data. The data strong suggested a value much lower than was commonly believed. Millikan silent discarded some of the data during publication giving a number lower than the prior consensus but not by much.
Subsequent papers repeated the experiment, but each publication successively lowered the estimate.
As it turns out the true value was close to the one Millikan actually found but did not report. Each successive researcher found similar evidence but fudged the facts to report an answer in line with what the community would accept.
OT, but since Lucy Skywalker mentioned this:
Pro David Deming at the University of Oklahoma-“I seem to remember Dr Deming was pushed out of his job last year.”
David Deming was removed from the College of Geosciences in 2004, sued the University of Oklahoma, then settled out of court and was granted transferral to the College of Arts and Sciences. SEE wikipedia for a summary.
http://en.wikipedia.org/wiki/David_Deming
Sources differ as to the problem: was it a vendetta against academic free speech?-or something else?
Wikipedia: “A major impetus to Deming’s transfer was evidently the dissatisfaction of Robert L. Stephenson, an OU alumnus and major donor. On November 4, 2003, an attorney representing Stephenson wrote to University of Oklahoma provost Nancy Mergler, complaining that Deming was “pursuing academic and personal interests outside of and not supportive of the School’s mission.”[56] The letter warned that if Mr. Stephenson’s concerns were not addressed, “his efforts and donations on behalf of the School will not continue.”[56]
“In a February 27, 2004 article in The Chronicle of Higher Education, Karen S. Humes, a former OU professor now at the University of Idaho, was quoted as stating that Deming’s transfer was part of an administrative pattern in the College of Geosciences. Humes claimed, ‘The administration in that college was quite willing to subvert normal procedures to make sure their agenda was followed.'”
Perhaps a lot of both?
Is the MWP like a dinosaur? the priests keep telling you to ignore it as it doesn’t exist.
IPCC “If it hadn’t been for those darn kids we would of got away with it”
“….The MWP reconstruction in the IPCC AR2 was produced by HH Lamb for England, mainly from documentary evidence….” Richard Telford (13:30:43)
Anyone who has bothered to read Lamb’s ‘Climate, History and the Modern World’ (1982) will be aware that Lamb’s reconstruction used data from a variety of sources, from many areas of the globe.
Once more time…
The data plot with the strong MWP in fig 1. (labeled IPCC 1990-2001) is a temperature reconstruction for the United Kingdom, a small area in North West Europe.
The remaining two data plots in fig 1. are temperature reconstructions for the entire Northern Hemisphere.
The plots in figure 2. are for individual proxy data sets, not temperature reconstructions for geographical areas (this is important because the plots in fig 1. are weighted to avoid bias that would result from data sources being unevenly distributed – geographically speaking)
They make different looking graphs because they are plots of different things.
Simples.
Jay, read:
”
Christopher Hanley (01:49:07) :
“….The MWP reconstruction in the IPCC AR2 was produced by HH Lamb for England, mainly from documentary evidence….” Richard Telford (13:30:43)
Anyone who has bothered to read Lamb’s ‘Climate, History and the Modern World’ (1982) will be aware that Lamb’s reconstruction used data from a variety of sources, from many areas of the globe.
”
I have heard of the origin etc of the original IPCC graph, and never before have i heard anyone say that it was only based on UK data – can you document this, please?
On top of this, my article shows difference in trend globally when you compare 1976-2000 data with 2001-2009 data.
To this you write:
”
The plots in figure 2. are for individual proxy data sets, not temperature reconstructions for geographical areas (this is important because the plots in fig 1. are weighted to avoid bias that would result from data sources being unevenly distributed – geographically speaking)
They make different looking graphs because they are plots of different things.
Simples.
”
Honestly i dont get your point. The origin and type of data group 1976-2000 is obviously similar to the data group 2001-2009. Both groups are data from single locations pretty well spread out over the globe. Only difference is the publishing date . But you seem to have this intuision (?) that if you just weighted data, averaged etc, then the data would suddenly change dramatically? Even though almost no datasets 1976-2000 shows what you want to see, they can be “averaged”.. and then.. ? And of course change in the IPCC direction? Have you any idea what so ever how extremely unlikely this is?
but please document your UK-claim, i would like to see that, ok?
And then heres over 5000 boreholes by Huang 1997 showin the exact same result i got for 1976-2000:
http://www.klimadebat.dk/forum/vedhaeftninger/huang1997.jpg
Due to wrong averaging?
There is another reason the MWP gives AGW trouble. Global circulation models are validated against past history. If the past history was warmer, then the models fail. I doubt any of the models have been validated against a true picture of the MWP.
Frank Lansner
For those here who don’t know, Hubert Lamb was the first director of CRU. He used material from all over the world and in my opinion the sheer depth and scale of his writing has never been surpassed. He talked very little of CO2 believing that natural influences were at work and realising the lessons that history teaches us.
tonyb
Not to be nit-picking, but I can almost imagine the following title, “When the IPCC Tried to Deny the Existence of the Medieval Warm Period.” I suspect Hamlet, if he existed today, might have something very quotable to say about ‘the state of’ Climate Science. This ‘disappearing’ of the Medieval Warm Period seems to signal an obvious attempt to redefine science to fit an agenda.