Shock, awe. Untruncated and unspliced data used in a new paper from Briffa and Melvin at UEA restores the Medieval Warm Period while at the same time disappears Mann’s hockey stick. Here’s figure 5 that tells the story:
Look at graph 5c, and you’ll see 20th century warmth matches peaks either side of the year 1000, and that for the TRW chronology 20th century warmth is less than the spike around 1750. This puts 20th century (up to 2006 actually) warmth in the category of just another blip. There’s no obvious hockey stick, and the MWP returns, though approximately equal to 20th century warmth rather than being warmer.
Whoo boy, I suspect this paper will be called in the Mann -vs- Steyn trial (if it ever makes it that far; the judge may throw it out because the legal pleading makes a false claim by Mann). What is most curious here is that it was Briffa (in the Climategate emails) who was arguing that some claims about his post 1960 MXD series data as used in other papers might not be valid. It set the stage for “Mikes Nature trick” and “hide the decline“. Steve McIntyre wrote about it all the way back in 2005:
A Strange Truncation of the Briffa MXD Series
Post-1960 values of the Briffa MXD series are deleted from the IPCC TAR multiproxy spaghetti graph. These values trend downward in the original citation (Briffa [2000], see Figure 5), where post-1960 values are shown. The effect of deleting the post-1960 values of the Briffa MXD series is to make the reconstructions more “similar”. The truncation is not documented in IPCC TAR.
I have to wonder if this is some sort of attempt to “come clean” on the issue. Mann must be furious at the timing. There’s no hint of a hockey stick, and no need to splice on the instrumental surface temperature record or play “hide the decline” tricks with this data.
Bishop Hill writes:
Well, well, well.
In its previous incarnation, without a MWP, the series was used in:
- MBH98
- MBH99
- Rutherford et al 05
- Jones 98
- Crowley 00
- Briffa 00
- Esper 02
- Mann, Jones 03
- Moberg
- Osborn, Briffa 06
- D’Arrigo et al 06
It rather puts all that previous work in perspective, since this new paper has identified and corrected the biases. It should be noted though that tree ring paleoclimatology is an inexact science, and as we’ve seen, even a single tree can go a long way to distorting the output. On the plus side, it is good to see that this paper defines and corrects biases present in the MXD and TRW series of the Tornetraesk tree ring chronology dataset. This is a positive step forward. I suspect there will be a flurry of papers trying to counter this to save Mann’s Hockey Stick.
From the journal Holocene:
Potential bias in ‘updating’ tree-ring chronologies using regional curve standardisation: Re-processing 1500 years of Torneträsk density and ring-width data
Thomas M Melvin University of East Anglia, UK
Håkan Grudd Department of Physical Geography and Quaternary Geology, Stockholm University, Sweden
Keith R Briffa University of East Anglia, UK
Abstract
We describe the analysis of existing and new maximum-latewood-density (MXD) and tree-ring width (TRW) data from the Torneträsk region of northern Sweden and the construction of 1500 year chronologies. Some previous work found that MXD and TRW chronologies from Torneträsk were inconsistent over the most recent 200 years, even though they both reflect predominantly summer temperature influences on tree growth. We show that this was partly a result of systematic bias in MXD data measurements and partly a result of inhomogeneous sample selection from living trees (modern sample bias). We use refinements of the simple Regional Curve Standardisation (RCS) method of chronology construction to identify and mitigate these biases. The new MXD and TRW chronologies now present a largely consistent picture of long-timescale changes in past summer temperature in this region over their full length, indicating similar levels of summer warmth in the medieval period (MWP, c. CE 900–1100) and the latter half of the 20th century. Future work involving the updating of MXD chronologies using differently sourced measurements may require similar analysis and appropriate adjustment to that described here to make the data suitable for the production of un-biased RCS chronologies. The use of ‘growth-rate’ based multiple RCS curves is recommended to identify and mitigate the problem of ‘modern sample bias’.
Here’s the money quote from the paper:
If the good fit between these tree-growth and temperature data is reflected at the longer timescales indicated by the smoothed chronologies (Figures 5c and S20d, available online), we can infer the existence of generally warm summers in the 10th and 11th centuries, similar to the level of those in the 20th century.
Conclusions
• The RCS method generates long-timescale variance from
the absolute values of measurements but it is important to
test that data from different sources are compatible in
order to avoid systematic bias in chronologies.
• It was found in the Torneträsk region of Sweden that there were systematic differences in the density measurements from different analytical procedures and laboratory conditions and that an RCS chronology created from a simple combination of these MXD data contained systematic bias.
• Both the known systematic variation of measurement values (both TRW and MXD) by ring age and the varying effect of common forcing on tree growth over time must
be taken into account when assessing the need to adjust subpopulations of tree-growth measurements for use with RCS.
• It was necessary to rescale the ‘update’ density measurements from Torneträsk to match the earlier measurements over their common period, after accounting for ring-age decay, in order to remove this systematic bias.
• The use of two RCS curves, separately processing fastand slow-growing trees, has reduced the effect of modern sample bias which appears to have produced some artificial inflation of chronology values in the late 20th century in previously published Torneträsk TRW chronologies.
• A ‘signal-free’ implementation of a multiple RCS approach to remove the tree age-related trends, while retaining trends associated with climate, has produced
new 1500-year long MXD and TRW chronologies which show similar evidence of long-timescale changes over
their full length.
• The new chronologies presented here provide mutually consistent evidence, contradicting a previously published conclusion (Grudd, 2008), that medieval summers (between 900 and 1100 ce) were much warmer than those
in the 20th century.
• The method described here to test for and remove systematic bias from RCS chronologies is recommended for further studies where it is necessary to identify and mitigate systematic bias in RCS chronologies composed of nonhomogeneous samples.
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“Simon says:
October 29, 2012 at 2:58 am
Did anyone else notice the large post-2000 increase in temperature?”
It’s not a rise in temperature it’s a rise in a supposed proxy for temperature. Or put another way a variation of “Mike’s Nature Trick” has not been used in this case to “Hide the Rise”.
And also thanks to
“Jean Parisot says:
October 28, 2012 at 5:53 pm
Empirical scum!”
Nice one, I think this could be a major boost to the tee-shirt industry.
Jan writes “You can’t logically or empirically refute the results of a scientific study, of any scientific study, by applying ad hominem arguments against the authors of the study.”
I dont need to, McIntyre has done that for me by looking at the actual science. If you understood what Mann has done with the hockey stick reconstructions then you would know what I say is not simply an ad hominem attack but instead an assessment of the motivations behind the “science” which the Melvin paper has now put even further into doubt. I expect that doesn’t sit well with you.
The fact is that papers that dispute past AGW results are coming to light with ever increasing frequency. There was a time when it was an all too common belief today’s warming was unprecedented but now that’s a much less certain proposition.
[ah . . here it is . . mod]
D Böehm :
At October 29, 2012 at 4:10 am you write in reply to Simon
With respect, you misunderstand Simon’s point because I also noticed the large post-2000 increase in temperature which is in the above graphs of Briffa’s results.
However, as your links show other data sets – including the data Briffa used for his calibration – do NOT indicate such a rise after 2000.
In other words, Briffa’s analysis also has a divergence problem.
Richard
Moderators:
Hmmm. Yet again my post seems to have gone in the ‘bin’: this time as a response to D Böehm.
I am starting to wonder if I have been selected for ‘special treatment.
I would welcome recovery of my post.
Richard
[nope . . there is nothing in the spam bin from you. Nope you have not been selected for “special treatment”. . . mod]
An illustrative comparison of this tree ring reconstruction of temperatures in Sweden to solar activity history, global temperature history by non-tree ring proxies, and arctic temperature history:
Overall it is notably supportive, as long as the sources are primarily not those heavily revised for CAGW-movement convenience:
http://s7.postimage.org/tc7f57vnv/composite2.gif
(click to enlarge and scroll)
Steven Mosher says:October 28, 2012 at 10:52 pm
fact alert.
this paper has little bearing on manns work.
its a seasonal recon.
its a local recon.
Yamal isn’t a local recon?
Anything growing in Siberia isn’t seasonal?
Good Grief!
richardscourtney wrote in
http://wattsupwiththat.com/2012/10/28/manns-hockey-stick-disappears-and-crus-briffa-helps-make-the-mwp-live-again-by-pointing-out-bias-in-ther-data/#comment-1127226
A climate scientist is a scientist who does research and publishes in scientific journals on past, present, and future climate of Earth, as a whole or aspects of it. There isn’t a big problem to define what a climate scientist is.
Also, you are not entitled to impose on others here what they are debating and what they aren’t.
The alleged “Mike’s Nature trick” to “hide the decline”, which is nothing more than a talking point, unproven assertions that are disseminated in fake skeptic opinion blogs and similar.
That is your assertion, according to which some studies, the exact references of which you avoid to provide here, would have achieved that.
Obviously you have an opinion, which you are trying to back up with a link to an opinion on another opinion blog.
And yet another lie by you, Mr. Courtney. I haven’t made such a claim which you are asserting here, certainly not “repeatedly”. Considering your previous lies about what I allegedly said, like in the context of my statements about the fraudulent Oregon Petition, there seems to be a pattern here.
Moderator,
Thankyou for your reply to me at October 29, 2012 at 5:08 am. This is a resend of the post which went somewhere.
Richard
D Böehm :
At October 29, 2012 at 4:10 am you write in reply to Simon
With respect, you misunderstand Simon’s point because I also noticed the large post-2000 increase in temperature which is in the above graphs of Briffa’s results.
However, as your links show other data sets – including the data Briffa used for his calibration – do NOT indicate such a rise after 2000.
In other words, Briffa’s analysis also has a divergence problem.
Richard
Jan, the only thing you have are warm temperatures in some places that have been warm enough to give a global average that is warmer when compared to some other period. We also have temperatures that are colder than that same comparison period. But of course, these are hidden in the global average. If there ever was a statistic that hides something we should know, it is the global average. But it is a useful statistic if you want to use it for some other purpose than explaining Earth’s temperatures. AGWers use the global average for some other purpose me thinks.
You don’t have a lot. You do not have correlation. You do not have causation. You do not have models that are predictive. You have not ruled out natural intrinsic ENSO factors, along with ENSO variations in oceanic temperatures, clouds and pressure system spin offs. ENSO factors do not swing like a pendulum, something many climate scientists are now beginning to realize.
What you do have is the same sorry set of statistics re-read over and over again. That kind of scientific reporting does not a case make.
D Böehm wrote in
http://wattsupwiththat.com/2012/10/28/manns-hockey-stick-disappears-and-crus-briffa-helps-make-the-mwp-live-again-by-pointing-out-bias-in-ther-data/#comment-1127277
Is this comment by “D. Böehm” supposed to refer to an actual statement by me? Or is he just making something up?
tallbloke says:
October 29, 2012 at 1:21 am
So, you are unable or unwilling to back up your slanderous accusation with any checkable facts.
First, this was no slanderous accusation, just a statement of fact, and your fact checking as Mosh points out does not have a good track record. Second, as you well know, the review process is confidential and reviewers are not allowed to divulge details.
No matter, I’ll ask Abreu and Steinhilber
You could also ask them to publish [e.g. on your blog] the [many and detailed] reviews of their paper. Personally, I publish the reviews of my own papers, accepted or not. This allows people to judge the review process.
Jan Perlwitz,
From numerous comments I assume you believe that global warming is continuing. Correct me if I am wrong. And my apologies to Simon for misreading his comment, and thanks to Richard Courtney for pointing it out.
Jan P Perlw1tz
This is a response to your pathetic post at October 29, 2012 at 5:56 am.
It says to me
Quite correct, only Anthony can do that, and he chose the subject of this thread; not me and not you. I pointed out that your comment was an irrelevant distraction from the thread.
You follow that with this
The only person you may be fooling with that nonsense is yourself.
Not content with that nonsense, you quote my accurate and precise statement which said
And you say
No! Unfounded assertions are your habit and not mine. My statement is merely a mention of documented historical fact. If you truly are as ignorant as you claim to be then read the relevant peer-reviewed papers. It is not my duty to do the homework required to overcome your self-imposed ignorance.
I referred to basic statistical procedural flaw with treemometry and linked to an explanation of it for non-statisticians from Lucia.
http://rankexploits.com/musings/2009/tricking-yourself-into-cherry-picking/
And your reply to that says in total
No, I have a conclusion – not an opinion – based on the studies of professional statisticians published for your benefit in peer-reviewed literature. And that is why I said
Obviously you have a prejudice which prevents you accepting the truth.
You follow that a set of blatantly deliberate falsehoods.
I wrote and you quoted my writing
then you write this blatant and clearly deliberate set of falsehoods
I have NOT made any “l1e” but you have made a series of l1es including the clearly deliberate set of falsehoods I quote here. The pertinent thread is at
http://wattsupwiththat.com/2012/10/27/weekend-open-thread-3/
Your support of the Oreskes paper together with your lies about the Oregon Petition, about me, and about what I said of your comments are there for all to read. And people can also see how in that thread I and others refuted your l1es, others supported my factual statements, and nobody supported anything you said.
There is a “pattern here”. Everybody can see it. And it is time you stopped doing it.
It seems you really are a piece of work.
Richard
Here’s another paper from March 2012 using Ikaite proxy.
http://wattsupwiththat.com/2012/03/22/more-evidence-the-medieval-warm-period-was-global/
@Wellington
Since you chose to bring it up why not ask you?
Maybe he’s said all he can. If he was a reviewer for a journal that rejected, it’s possible that reviewer policy doesn’t allow him to say, or he may be getting a source in trouble by saying which one (it’s possible that the association with a particular reviewer might make it obvious.) I don’t know the answer, but not revealing sources or which Journals have rejected it is not an admission of not knowing, nor is it slander.
Even in absence of specific knowledge, you are talking about a field where Leif publishes and is influential. He has more than a rough idea of where the paper fits in the submission hierarchy for this type of paper. If he sees a paper published in lesser journal than would be expected for the conclusions and authors of said paper, there is a very logical reason to assume that it had been passed over one or more times.
I sometimes wonder why people continue defending the hockey stick. It is really a waste of time and effort and one could be putting their resources into something more productive.
“D Böehm” wrote in
http://wattsupwiththat.com/2012/10/28/manns-hockey-stick-disappears-and-crus-briffa-helps-make-the-mwp-live-again-by-pointing-out-bias-in-ther-data/#comment-1127388
No, you are not wrong with respect to that. I’m very convinced that the physical process of global warming is continuing, which appears as a statistically significant increase of the global surface and tropospheric temperature anomaly over a time scale of about 20 years and longer and also as trends in other climate variables (e.g., global ocean heat content increase, Arctic and Antarctic ice decrease, mountain glacier decrease on average and others), and I don’t see any scientific evidence according to which this trend has been broken, recently.
However, this doesn’t mean this trend must be statistically detectable on any arbitrarily short time scale, like 10 years, or 5 months, or 2 days. It doesn’t mean the surface or tropospheric temperature anomaly must linearly increase from one year to the next, or be larger each five years than the previous five years. It doesn’t mean that there can’t be any natural variability that appears as wobbles in the temperature record (or in other climate variables), masking the multi-decadal temperature trend over a time scale shorter than 20 years with the effect that the longer term trend is not statistically detectable in the time series, if one chooses the time period only short enough.
Leif: “I fail to see the ‘logic’. The top is cut off, so you can’t tell if it was 1936 or 2003.”
1) I’m suggesting they cut off the graph so you “can’t tell if it was 1936 or 2003”.
2) If tree rings made good thermometers, they would not be affected by UHI leaving the 1930s as the warmest decade.
It’s good to see that Michael Mann’s bio at Penn State has been corrected.
“co-awarded” now reads “contributed… to the award”
http://www.nationalreview.com/corner/331829/mikes-nobel-trick-mark-steyn
Now he should consider correcting his Brothers Grimm style Hockey Stick.
sunshinehours1 says:
October 29, 2012 at 7:41 am
Leif: “I fail to see the ‘logic’. The top is cut off, so you can’t tell if it was 1936 or 2003.”
1) I’m suggesting they cut off the graph so you “can’t tell if it was 1936 or 2003″.
“A thief thinks everybody steals”
tallbloke says:
October 29, 2012 at 12:24 am
Hi Roger,
it is important to clarify some issue here.
About Tim Channon’s graph. It shows that Steinhilber’s TSI has a quasi millennial oscillation and a bisecular one. This result is not really surprising nor new. Steinhilber’s TSI is based on typical nucleotide records. These oscillations were noted far before Steinhilber. For example Bond et al 2001 on Science.
The novelty of my paper
Scafetta N., 2012. Multi-scale harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter-Saturn tidal frequencies plus the 11-year solar dynamo cycle. Journal of Atmospheric and Solar-Terrestrial Physics 80, 296-311.
is not to have found a quasi-millennial oscillation in the solar record and the other oscillations, which was already well known, but to have deduced theoretically those oscillations in both phase and timing. In fact, my model is a hindcast of the data, not a simple fitting of the data.
About “key frequencies were found by Bart” etc.. I need to disagree. What happened is that Leif who was chosen as a reviewer of my paper had the “honest” idea to put on WUWT some of the results of my analysis without saying that he got them from my paper.
Several of his comments show that he knew too much about my paper.
For example, he says referring to me:
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/#comment-706506
(But are you now abandoning your view that the planetary influence is
tidal [spring tides Saturn-Jupiter and perihelion tides from Jupiter]?)
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/#comment-706594
(Except that Scafetta believes his solar variations have a tidal origin
and is not related to solar velocity.)
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/#comment-706608
(Scafetta believes solar activity is caused by tides)
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/#comment-706736
(I’ll try to paraphrase what I think you are saying: the planets raise
tides in the sun’s interior. These tides modulate [or even cause] solar
activity. Solar activity thus have cycles driven by the planets.) (please note that this is quite correctly what I say in my papers)
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/#comment-707053
(Even your own work on tidally induced solar cycles was already done by
Brown 111 years ago.) (note that Leif is explicitly referring
to my own “work” on planetary tides on the sun also if he adds a
ridiculous comment regarding Brown)
Finally, in
http://wattsupwiththat.com/2011/07/25/loehle-and-scafetta-calculate-0-66%c2%b0ccentury-for-agw/#comment-709699
he shows the following figure uploaded to his web-site
http://www.leif.org/research/FFT-Daily-Sunspot-Number.png
in this figure he repeats my spectral analysis showing that
the Schwabe 11-year sunspot number cycle can be decomposed in three peaks
two of which close to the 9.93-year Jupiter and Saturn spring-tide and
the 11.86-year Jupiter tide. Plus a middle peak close to my 10.9-year,
which is the major finding in paper on which I build my model.
Bart apparently took the idea from Leif’s comments and figures that were taken from my paper.
Note that the behavior of Leif (disseminating in internet my results and ideas taken from my paper that he was refereeing) is a seriously break of the ethical code of the journal.
So, I do not think that my paper was based on ideas took from your web-site in some way. On the contrary, I have indirectly originate some of the ideas published on your web-site, even if you did not knew it.
Note that the first version of my paper was submitted on Dec/22/2010, by the way, and the first referee was not able to find any error. Then the hostile editor started looking for biased reviewers and after that I demonstrated that the second reviewer was an idiot, the editor was forced (also by the manager editor, I think) to reject him and sent the paper to Leif to be sure to get another biased review.
richardscourtney in
http://wattsupwiththat.com/2012/10/28/manns-hockey-stick-disappears-and-crus-briffa-helps-make-the-mwp-live-again-by-pointing-out-bias-in-ther-data/#comment-1127407,
makes a lot of noise again and also claims:
We can make it easy, Mr. Courtney, and examine your lies, about which you claim they are none, one by one. Let’s start with the most recent one:
In
http://wattsupwiththat.com/2012/10/28/manns-hockey-stick-disappears-and-crus-briffa-helps-make-the-mwp-live-again-by-pointing-out-bias-in-ther-data/#comment-1127226
you asserted following about what I allegedly claimed:
In either case, as you say, it has been supported by the 75 people whom you have repeatedly claimed are 97% of ‘climate scientists’.
Please provide the original quotes where I allegedly said such a thing, together with proof of sources. The burden of proof for your assertion is on you, and since you insist you didn’t tell a lie, you should be able to provide the requested. Or you can retract your assertion, apologize, and come up with any excuse for telling a falsehood, like you have been temporarily out of your mind, when you made this assertion, or whatever else you like.
Nicola Scafetta says:
October 29, 2012 at 7:55 am
in this figure he repeats my spectral analysis showing that the Schwabe 11-year sunspot number cycle can be decomposed in three peaks […] which is the major finding in paper on which I build my model
My analysis was based on Vuk’s ideas of the three peaks, long before yours, so your whining is misplaced. Brown already discussed this back in 1900: http://www.leif.org/research/AGU%20Fall%202011%20SH34B-08.pdf
Leif Svalgaard says:October 29, 2012 at 8:06 am
Leif, you have “rediscovered” those ideas and references (including Brown paper) after having read my paper. So, your dishonesty is quite compelling. I just hope that Anthony opens his eyes, and understand who you really are. Also your presentation at AGU was partially inspired by my paper that you have read.
About Brown, he did not find those peaks in the sunspot record. He did not calculate any power spectra of the data. Brown simply “conjectured” that the 11-year solar cycle could be constrained by the Jupiter-Saturn spring tide (9.93 yr) and Jupiter tide (11.86). But he did not go further than that. http://articles.adsabs.harvard.edu/full/1900MNRAS..60..599B
It is my papers that have demonstrated that idea works.
About Vuk’s ideas he was talking about the double cycles (19.86 yr and 23.7 yr). Vuk’s model does not have anything to do with my model, although you thought that it was equivalent to mine. Your arguments are nonsense.
Nicola Scafetta says:
October 29, 2012 at 7:55 am
in this figure he repeats my spectral analysis showing that the Schwabe 11-year sunspot number cycle can be decomposed in three peaks […] which is the major finding in paper on which I build my model
About the ‘three peaks’: here is my analysis of those [from Monday, January 26, 2009, 11:17:46 PM] and ‘published’ on a blog the same day http://www.leif.org/research/Vuk-SAM.pdf slide 2 discussing Vuk’s ‘sunspot formula’. Perhaps this is where you got the idea from in the first place?