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.
Nicola Scafetta says:
October 29, 2012 at 11:58 am
I thought that you opposed the planetary theory of solar variation because in your opinion no evidences existed!
I oppose it because your so-called ‘evidence’ is just numerology. The 2nd referee [whom you called an ‘incompetent idiot’] emailed me this:
“Dear Leif,
Congratulations on your very clear demonstration of the numerological origins of Scafetta’s “planetary effects”. It would make a great rebuttal of that paper if it is ultimately made public on some forum.
On the other hand, as I just explained to the Editor, after getting more familiar with Scafetta’s activities in the blogosphere I have now revised my earlier suggestion and I do not think that a refereed journal would be the right place for the paper. The guy simply seems unfit to lead a rational debate; if his paper were published, no matter if it remains uncited or it is rebutted, he would be able to show it up as a refereed publication; he might even demand that a 2nd paper of his be published with his arguments” against the rebuttal etc. So now I would suggest the paper for plain rejection. I gather you would agree with this solution?”
And I’m saying that your claim that I got the three-peak notion from you is false.
P.S. Where are the other reviews?
vukcevic says:
October 29, 2012 at 12:09 pm
S & S please do go on. LOL.
Yes, this is good entertainment.
Leif, thanks for the TSI info.
I stuffed it into a new spreadsheet along with the historical reconstruction available on the SORCE data page.
Data prep for matching: Subtract 1/24 (half a month) from your times for start of month, then averaged the years. From SORCE reconstruction, subtract the 0.5 from (half year) from times.
Observations:
Yours has an apparent implicit minimum of approx. 1360.9 W/m².
Yours has at least twice the variability, SORCE shows a peak height of one, yours has a height of two to two and a half. Artifact from smoothing?
Yours tracks SORCE at about 0.2 higher, going backwards until about 1950. Then SORCE takes a great bend downward, opening the gap to about 0.5.
If you’re in to seeing cycles and patterns, the SORCE reconstruction has an approx. 90 year “beat” going by the minimums. By eyeball, 1720 to 1810, 1810 to 1900. If it had not taken the great bend downwards, it might be more obvious if we have passed the end of a cycle around 1990. As it is, such an end cannot be detected.
But with only two, arguably three, “cycles” visible, it seems likely they are an artifact of the program generating the SORCE reconstruction rather than a real pattern.
The great bend downward is questionable, as recent corrections to the SSN have removed the evidence of a recent solar grand maximum (1945-1995) that is apparent from the great bend to present. Since the SSN corrections are recent and the SORCE reconstruction is generated once a year, last time was Jan 19, 2012, perhaps the great bend will be removed in future versions.
@AlanG October 28, 2012 at 11:26 am:
“But. But. If I want my trees to grow more I water them. Why this dendrothermometry?”
Exactly. One characteristic cannot be a proxy for two variables. You can try to get either precip or temp – pick one, but you can’t have both (you can’t have your cake and eat it, too). And since both are actually factors – of unknown and varying forcing, relative to one another – I challenge anyone to tell me with a straight face which – rain or temps – determines the TRW or MXD. Of course, they can’t. The entire dendroclimatology thing is a farce (I hate to use the word, but it is true), because they pretend that rainfall is a constant. The discipline (I hate to use the word, because it isn’t disciplined, when looked at this way) HAS to assume rainfall as constant, or else the ‘science’ can’t work. And seen from this perspective it doesn’t.
Since both (and other factors, too) TOGETHER comprise the forcing for TRW and MXD, the graphs tell us about beneficence of the climate, but only as related to what is optimum for tree ring width and density to form/grow in summers – but also without delineating how much of each was acting on the tree growth.
The reason that there ever WAS a divergence problem is because neither TRW or MXD really were ever proxies for temps. With the same temperatures, two data points in time on the same tree can – and will – result in higher TRW or MXD values, if the rainfall is more conducive to growth. When this happens dendroclimatology misses the mark, because rainfall is not taken into account.
Steve Garcia
Leif Svalgaard says: October 29, 2012 at 12:09 pm
Leif, you are further demonstrating that the review process was colored and there was an orchestrated decision.
Well Leif, I have an idea. Why don’t you write a comment on my paper using your critique.
You may coauthor it with your friend who believes that it is robust. He may also add his argument that he could reproduce the 11-year solar cycle and its secular and millennial variation by superposing two harmonics with periods of 12 2/3 year and 14 year. (How can it be possible!)
See, Leif, the second referee initially claimed that my paper had to be published together with his comment disproving it. I said that for me it was ok, I could add a short response. Then the referee saw my response and changed idea.
To Anthony,
Anthony, are you realizing that more and more papers are being published in support of the planetary theory of solar variation by numerous journals? And people like Leif are not able to disprove anything? Just use smearing logic and insinuations?
What else do you want that it is published before you consider at least the possibility that the theory could be correct or at least interesting?
davidmhoffer 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-1127757
You are just repeating the fait-accompli fallacy.
There are many things going around in the “skeptic” blogosphere, which are thought among “skeptics” to be “well known”, but which are just total BS or nonsense without any scientific validity, for instance the believe that “global warming stopped”.
There is some lack of honesty on your side, if you make some innuendo with respect to statements by me, but refuse to substantiate and to be specific, and so leaving me without any chance to examine the validity of your hidden argument.
But it’s your choice, of course.
And why should I have answered those questions? Why would I have the burden to answer some questions you just have made up because you felt like it? That’s how I see these questions. I may be more willing to answer some questions, if those questions are in reference to some statements and argument I actually made.
On a side note: It’s just pathetic how Mr. Coal-Transport-Magazine Editor tries to influence other commenters now, after he has been exposed to have made claims he can’t back up with quotes and proof of source, because his claims are lies. He just could have admitted that he was wrong, when he made those claims.
I don’t know the scientific merit of this paper yet, but at least one true proposition can already be derived from it with very high confidence.
Briffa has deseted the Team
Jan Perlwitz says:
” 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.”
I find this assertion interesting, as it is often claimed that natural variability can mask global warming over short time periods. In this context “natural variability” seems to be a catchphrase for unknown forcings and feedbacks that change global temperature in ways that we can’t predict or quantify. If these unknown factors are masking global warming, then it’s obvious that they must be equal in scale to the warming itself.
Warmists, and the oft-cited list of responses to AGW skeptics, also claim that when all of the natural forcings are considered, their sum is inadequate to explain the observed temperature rise since 1975. How can these same scientists, in the same breath, admit that there are unknowns that are similar in scale and able to offset AGW for an extended time period, and still dismiss the same natural variability as the primary driver in any observed temperature increase?
This is similar to the error they make when they claim that greenhouse gases can produce temperature increases 3-5 times that of the direct radiative effects of doubling CO2 (through the action of non-linear feedbacks), but deny that small changes in insolation can produce effects that are much larger than can predicted from the original forcing.
Climate science, with it’s many interconnections with fields of study such as geology, astronomy. physics, history, archaeology, mathematics and biology, could be the most fascinating area of pure research for brilliant researchers to study. Instead, it’s riddled with small-minded tyrants who love the attention that comes with political activism, and have little to no intellectual curiosity about what all of the loose ends and inconsistencies could tell us. They’ve staked their careers to one issue, and they have nothing to lose at this point by defending it to the last.
Leif Svalgaard says: October 29, 2012 at 12:09 pm
I would like to add an additional comment on the interesting email between Leif and the second reviewer.
Leif was the third reviewer of my paper, who was contacted by the journal AFTER the second reviewer final decision.
The email posted by Leif clarifies the timing of what really happened.
This is what appears to be happened.
1) The second reviewer received my rebuttal and evidently he could not respond.
2) So, he contacted Leif, sending him my paper and asked for suggestions.
3) Leif wrote his report with his critique and send it to the second reviewer. The reviewer responded to Leif by sending him the above email.
4) The reviewer returned his rejection decision to the editor without rebutting my rebuttal, but asking the editor to contact Leif.
5) The editor contacted Leif.
6) Leif submitted his negative report.
So, it appears that it is Leif who is behind the decision of the second referee who was not able to write a proper rebuttal to my paper, so he contacted Leif.
In conclusion, my paper was rejected by Leif. And the editor followed the suggestion of the second referee despite the referee could not rebut my rebuttal.
Which demonstrates the bias of the editor.
Nicola Scafetta says:
October 29, 2012 at 12:54 pm
there was an orchestrated decision.
Unanimous decision that the paper was junk. A ‘bad egg’ as Easterbunny said.
Why don’t you write a comment on my paper using your critique.
We considered that [I suggested that], but in the end we decided that your paper was not really worth it. See the email upthread.
What else do you want that it is published before you consider at least the possibility that the theory could be correct or at least interesting?
There is no ‘theory’, but a host of equally disparate and mutually conflicting pseudo-scientific hand waves. Not even a communal set of predictions [spaghetti graph] for the 21st century where each proponent gets to plot a curve with a different color. Tallbloke volunteered to make one, but has not done so.
kadaka (KD Knoebel) says:
October 29, 2012 at 12:53 pm
perhaps the great bend will be removed in future versions
The SORCE reconstruction is based on two assumptions [both likely to be false]:
1) the Group Sunspot Number is correct
2) there is a ‘background’ variation which is equal to the 11-year moving average of the Group Sunspot Number on which TSI rides. http://www.leif.org/research/TSI-Background-Not.png
Leif Svalgaard says: October 29, 2012 at 1:25 pm
Why don’t you write a comment on my paper using your critique.
We considered that [I suggested that], but in the end we decided that your paper was not really worth it. See the email upthread.
To Anthony.
Anthony, note that Leif is not going to write a proper scientific rebuttal to my papers. So, my papers stand.
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-1127689
I’m curious what Courtney, Stephen Richards, and their likes are going to say and do, when it is clear after 20 years that I, together with mainstream climate science, have been right and there is still an intact global warming trend in the global temperature anomaly also for periods starting around 1997, when global warming allegedly “stopped”, according to Courtney and likes.
Reasonable folks, who have believed in the “skeptic” meme will probably acknowledge that they got fooled by internal natural variability and scientifically flawed statistical analysis presented to them by “skeptics”. I suspect, though, that the Courtneys and Richards will totally delve into lunacy and conspiracy fantasies then, if they haven’t already done so.
Well, I’m going to tell the crowd here then, regarding the global warming trend, “I told you so!”.
Please bear in mind that the reconstructions will reflect GROWING SEASON conditions; summertime, essentially. Also, even though I can’t recall precisely, I remember a paper or three that pointed out the LIA also had very high variability. Some summers much cooler, others not so much. Also, while the summers generally were a bit cooler, the winters were way cooler (on average). Finally, ALL of this is based on proxies. At best, IMHO, a first-order approximation to actual conditions.
Jan P Perlwitz says:
October 29, 2012 at 9:37 am
davidmhoffer 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-1127554
Phil Jones: 15 years
Ben Santer: 17 years
JanP: 20 years
Seems to be a trend here….
With what exact statements by Jones and Santer are you comparing my statement? Please provide proof of source for the statements of the two, not just assertions from the “skeptic” rumour kitchen.
Perhaps these?
Tuesday, January 10, 2012
Email 4199, a ClimateGate twofer from Phil Jones: “the no upward trend has to continue for a total of 15 years before we get worried”;
See: http://tomnelson.blogspot.ca/2012/01/email-4199-climategate-twofer-from-phil.html
See
https://www.llnl.gov/news/newsreleases/2011/Nov/NR-11-11-03.html
“They find that tropospheric temperature records must be at least 17 years long to discriminate between internal climate noise and the signal of human-caused changes in the chemical composition of the atmosphere.
“One individual short-term trend doesn’t tell you much about long-term climate change,” Santer said.”
Jan P Perlw1tz
There is some lack of honesty on your side, if you make some innuendo with respect to statements by me, but refuse to substantiate and to be specific, and so leaving me without any chance to examine the validity of your hidden argument.
>>>>>>>>>>>>>>>>>
There’s an entire thread on the topic with quotes and links.
http://wattsupwiththat.com/2012/10/15/noaas-15-year-statement-from-2008-puts-a-kibosh-on-the-current-met-office-insignificance-claims-that-global-warming-flatlined-for-16-years/
Now since you insist on me making you look foolish on what in fact IS common knowledge, I guess I have to oblige. Your welcome.
Now are you going to answer my questions, or find some new excuse?
@Nick
Thankyou for introducing me to the potent new form of logic – “argument by proverb”.
All I need to to I tag my approriate proverb to the end of every opposition argument to invalidate it and if carefully chosen enough this will also smear their name.
PS: Not all theives think everyone steals and many honest people think theives steal.
To steal the potency of my argument I follow with the delightful African proverb: “A leopard never changes its spots”.
be warned however I know many other delightful proverbs.
Sorry that was meant to be @ur momisugly Lief but I am in a rush literally investigating a possible theft.
JohnH 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-1127917
No, it’s not a catch phrase for “unknown forcings and feedbacks”. Forcings are external drivers of climate variability. “Natural variability” in my statement refers to internal variability, the climate system exhibits, even if the forcings stay the same. So, if it clarifies my statement add “internal” or “unforced” as additional adjective to “natural variability”. Sorry, if my statement wasn’t clear enough with respect to that.
The fact that unforced variability in the climate system can offset anthropogenic forcing changes on a time scale of about 15 years and smaller does not logically imply that unforced variability is also the primary cause of the statistically significant temperature increase since the mid 1970ies. And who of “these same scientists” is supposed to have said that the unforced natural variability was of similar scale as the temperature increase since the mid 1970ies?
Red herring. Such a thing is not being “denied”.
Friends:
I see that at October 29, 2012 at 1:47 pm the troll says he has failed to notice global warming stopped 16 years ago. Well, he has to pretend he has not noticed if he wants breath life back into the AGW scare and, thus, keep making a living from it.
Of course, the present period with lack of discernible global warming or cooling will come to an end sometime. Hopefully, it will end with warming towards the temperatures of the MWP because cooling towards temperatures of the LIA could start. Warming is not a problem but cooling would be.
Importantly, the IPCC’s “committed warming” has vanished. Either it did not exist or it is hiding somewhere possibly in the same place as Trenberth’s “missing heat”. Perhaps the troll is hiding them behind his sofa?
Richard
JPP, thought you were a GISS employee. Shouldn’t you be evacuating NYC?
(Note: the rhyming was unintentional. And somehow funny.)
Leif Svalgaard says:
October 29, 2012 at 1:25 pm
………
Hi Doc
There is more than a passing similarity between your GSN (Group Sunspot Number) and the NAP (North Atlantic Precursor)
http://www.vukcevic.talktalk.net/GSN-NAP.htm
not numerology but natural correlation based on well known and accepted data.
Solar influence is far dipper than just the ‘thin air’ temperatures. A bit of a problem for you and your solar group, not to mention Perlwitz and his CAGW doomsters cabal.
Friends:
This one is a beauty.
At October 29, 2012 at 2:20 pm the troll writes
Tru, it “does not logically imply” that.
It demonstrates there is no reason to invoke a hypothetical “anthropogenic forcing” as an explanation for “the statistically significant temperature increase since the mid 1970ies”.
And it shows the hypothetical “anthropogenic forcing” does NOT provide “committed warming” which the IPCC says it must provide if the hypothetical “anthropogenic forcing” is to cause significant warming.
However, it should be noted that making a living from the AGW-scare – as the troll does – requires invoking a claim that such a hypothetical “anthropogenic forcing” is the the explanation of “”the statistically significant temperature increase since the mid 1970ies”.
Richard
Nicola Scafetta says:
October 29, 2012 at 1:22 pm
Leif was the third reviewer of my paper, who was contacted by the journal AFTER the second reviewer final decision.
This is correct
2) So, he contacted Leif, sending him my paper and asked for suggestions.
This is wrong, that is not how reviews are done [have you ever done one?]. The Editor asks me to review at which point I don’t know how many other reviewers there are and what they said. The reviewers don’t see each others’ until the final decision letter.
“Easterbunny’ contacted me afterwards [via the Editor] about writing a rebuttal:
“On the other hand, as I just explained to the Editor, after getting more familiar with Scafetta’s activities in the blogosphere I have now revised my earlier suggestion and I do not think that a refereed journal would be the right place for the paper. The guy simply seems unfit to lead a rational debate”
We decide not to respond as the paper is not worth it.
Nicola Scafetta says:
October 29, 2012 at 1:43 pm
Anthony, note that Leif is not going to write a proper scientific rebuttal to my papers. So, my papers stand.
Your paper is not worthy of further reviews. You paper has already fallen flat. Bad papers are better forgotten than rebutted. Rebuttal just keeps them on unnecessary life-support for a while, until final oblivion.
Now, I asked for the other reviews. Are you too embarrassed to show them?
Please keep the entertainment coming. And continue telling Anthony what he should pay attention to.
Jan P Perlwitz says:
October 29, 2012 at 2:20 pm
“The fact that unforced variability in the climate system can offset anthropogenic forcing changes on a time scale of about 15 years and smaller does not logically imply that unforced variability is also the primary cause of the statistically significant temperature increase since the mid 1970ies.”
But, it does more-than-imply that you cannot rule it out, either. You actually have no idea of the correlation time of the natural variability, and have just grabbed “15 years and smaller” out of the air. Unknown means unknown. And, if you do not know, then why should we take painful and quite likely futile action against the unknown? What you are advocating is on a par with leechcraft and virgin sacrifice.
vukcevic says:
October 29, 2012 at 3:08 pm
There is more than a passing similarity between your GSN (Group Sunspot Number)
I don’t have a ‘Group Sunspot Number’. I showed that the official Group Sunspot Number is flawed and should not be used anymore…