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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15 years..17 years…20 years…
The funny thing (to me) about this is that when I first started following the climate debate, there was a slight warming trend in place. Plenty of people pointed out that it was well within natural variability. The climate scientists at the time came out with detailed explanations of how this couldn’t possibly be natural variability.
What a change a decade makes! Now the very same people are arguing that the lack of warming is because of natural variability!
Leif Svalgaard says:
October 29, 2012 at 1:25 pm
Nicola Scafetta says:
October 29, 2012 at 12:54 pm
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.
The biggest hand wave of all is you saying at one moment that there are no resonances in the Sun lasting more than 5 minutes, then in the next moment invoking a 120 year modulation of a ~11yr ‘dynamo cycle’ in order to be able to claim that the other peaks in the spectrum at 9.93 and 11.86 are just sideband harmonics of the 120yr and ~11yr periods and only coincidentally the orbital period of Jupiter and the tidal period of Jupiter and Saturn’s synodic cycle. Your logic contradicts itself.
Tallbloke volunteered to make one, but has not done so.
This is a lie. What I said was that I would get around to it if and when Leif showed us a dynamologists plot forecasting the 21st century from dynamology theory.
He made his excuses and left.
tallbloke says:
October 29, 2012 at 3:59 pm
120yr and ~11yr periods and only coincidentally the orbital period of Jupiter and the tidal period of Jupiter and Saturn’s synodic cycle.
Those periods are not stationary, i.e. they change over time, contrary to planetary cycles. And tides won’t work anyway. In short, you have no ‘theory’. No equations, no numbers, no physics, no nothing.
What I said was that I would get around to it if and when Leif showed us a dynamologists plot forecasting the 21st century from dynamology theory
As dynamo theory cannot predict more than a cycle ahead I don’t need to show that we can’t. You, on the other hand claim to be able to predict thousands of years ahead. So, prove it with just a century. And plot all the ‘predictions’ from planetary enthusiasts [if any].
He made his excuses and is still waiting. Perhaps you drop the predictability claim?
“new maximum-latewood-density (MXD) and tree-ring width (TRW) data from the Torneträsk region of northern Sweden”
If it was only taken from a small geographic location it is not a proxy for global temperatures in my book. For example, we know that a negative El Nino Southern Oscillation leads to warmer temperatures in these regions but it is much (MUCH!) cooler in the south pacific western regions.
tallbloke says:
October 29, 2012 at 3:59 pm
120yr and ~11yr periods and only coincidentally the orbital period of Jupiter and the tidal period of Jupiter and Saturn’s synodic cycle.
The 120-yr ‘cycle’ has only been with us 300 years. The Abreu paper you refer to, does not mention or predict a 120-yr cycle, so its appearance at the present time is indeed a coincidence.
Jai Mitchell says:
October 29, 2012 at 4:14 pm
If it was only taken from a small geographic location it is not a proxy for global temperatures in my book.
Yet, solar [and planetary] enthusiasts claim that the proxy ‘fits nicely’ with their cycles.
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-1127986
In a way I’m glad that you link to this article by Mr. Watts on his blog. It seems to me no one of the “skeptics”, including you, has bothered to do any fact checking, although at least one of the commenters has done it. You don’t seem to have paid attention to him.
Mr. Watts gives following quote (in a somewhat confusing way that gives the impression at first, it is taken from some Daily Mail article) from the State of the Climate Report 2008:
“Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model’s internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”
Source: http://www1.ncdc.noaa.gov/pub/data/cmb/bams-sotc/climate-assessment-2008-lo-rez.pdf
So, this is apparently one of the statements to which you refer that they were “common knowledge”.
However, Mr. Watts omitted an important part of the quote in his article. Here is a longer version of the quote, which I have taken from the report (p. S23):
ENSO-adjusted warming in the three surface temperature datasets over the last 2–25 yr continually lies within the 90% range of all similar-length ENSO-adjusted temperature changes in these simulations (Fig. 2.8b). Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model’s internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.
The 10 model simulations (a total of 700 years of simulation) possess 17 nonoverlapping decades with trends in ENSO-adjusted global mean temperature within the uncertainty range of the observed 1999–2008 trend (−0.05° to 0.05°C decade–1). Over most of the globe, local surface temperature trends for 1999–2008 are statistically consistent with those in the 17 simulated decades (Fig. 2.8c).
From the longer quote it becomes clear that the ruling out of Zero trends for intervals of 15 years or more refer to ENSO adjusted temperature changes, whereas Mr. Watts gives the impression in his articles those 15 years referred to the temperature changes as observed. In his article, Mr. Watts distorted the meaning of the quote he took from the report.
And then, further down, Mr. Watts writes following:
Climategate’s Phil Jones ‘insisted that 15 or 16 years is not a significant period: pauses of such length had always been expected, he said’ in 2012
‘Yet in 2009, when the [temperature] plateau was already becoming apparent and being discussed by scientists, Jones told a colleague in one of the Climategate emails: ‘Bottom line: the ‘no upward trend’ has to continue for a total of 15 years before we get worried.’
Using the third person, Phil Jones is supposed to have said something in 2012 about what he said in 2009? Really?
So, let me summarize what I have found under the link you gave me.
An article with a distorted quote from a climate report published in 2008 and with an alleged quote by Phil Jones in the third person about himself coming from second or third hand, a crowd of “skeptics” in the comment section, including you, who are taking all of this at face value without doing any fact checking and who see themselves confirmed in their preconceived views by this, and you are trying to sell this to me now as “common knowledge”.
This is why I ask for original quotes and for proof of source. This is why blogs like this are not reliable sources for alleged statements made by others, particularly by ones who are despised by Mr. Watts and his followers here.
You are welcome!
On a side note: Courtney’s announcement he made 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-1127600
to not respond to my comments in this thread anymore, was true only for as long. LOL
Leif Svalgaard says:
October 29, 2012 at 4:15 pm
The Abreu paper you refer to, does not mention or predict a 120-yr cycle,
Well clearly we need to convene some ‘workshops’ to get everyone singing off the same hymn sheet.
/sarc
tallbloke says:
October 29, 2012 at 4:46 pm
Well clearly we need to convene some ‘workshops’ to get everyone singing off the same hymn sheet.
That is what characterizes a mature science. But more importantly you need to get the various hymn sheet produced and compared. You claim you can predict with precision solar activity thousands of year in advance. Well, if every planetary prediction produces a unique, different curve from all the rest, then, of course, they are worthless and the theory is dead. So, get on with it, or admit you can’t.
Jai: “If it was only taken from a small geographic location it is not a proxy for global temperatures in my book. ”
What would you consider a valid proxy for global temperatures? I don’t think there is one.
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-1128177
It also seems to me that you are misrepresenting my statement as if I had said that it needed 20 years before the global temperature anomaly trends due to anthropogenic greenhouse gases could be statistically distinguished from unforced natural variability. If you aren’t, correct me, and explain what you want to state instead, please.
The truth of the assertions in this paragraph, how they are presented, can’t be tested. Therefore, they are just irrelevant blabber.
Werner Brozek wrote
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-1127983
And this is yet another example how “skeptics” use distorted quotes to misrepresent statements by climate scientists. A longer version of the quote goes as follows:
The box is on page S20-21 of the bigger pdf. This is part of a much bigger article
on the State of the Climate System 2008 which will appear later in the year.
Bottom line – the no upward trend has to continue for a total of 15 years before
we get worried. We’re really counting this from about 2004/5 and
not 1998. 1998 was warm due to the El Nino.
(http://di2.nu/foia/foia2011/mail/4199.txt)
It’s the same context as the one I discussed in my reply to David M Hoffer, the State of the Climate 2008 Report. The 15 years refer to the temperature change after adjusting for El Nino, as it is described in the report.
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-1128045
On what empirical evidence is this assertion supposed to be based?
16 years ago put the starting point of the period at November 1996.
Although global warming isn’t just a process concerning the global temperature, here are the global surface and lower tropospheric temperature trends in K with the 2-sigma ranges over those 16 years, using the trend calculator at http://www.skepticalscience.com/trend.php
GISSTEMP: 0.104+/0.121
NOAA: 0.082+/-0.12
HADCRUT4: 0.089+/-0.124
RSS: 0.032+/-0.214
UAH: 0.114+/-0.214
With the exception of RSS, which seems to be an outlier among the datasets, the trends over those 16 years are discernible, even if they are not statistically significant at the 95% level. The usual caveats about using too short datasets apply.
Those trends are quite similar to the ones of another 16 year period, the period from 1980 to 1995. Global warming didn’t stop back then either. Courtney’s assertions, which are based on logically false reasoning, abusing statistical analysis, don’t have any scientific validity.
Friends:
As usual, the troll cannot restrain himself from presenting a falsehood. This time at October 29, 2012 at 4:45 pm where he writes
But I did not say that. At October 29, 2012 at 9:39 am I wrote to him saying
I have not and I will not respond to him. But that does not mean I intend to ignore his posts.
I have and I will point out the falsehoods of the egregious and self-serving troll who is contaminating WUWT in his attempt to continue making a living out of the AGW-scare.
Richard
I think it would be a powerful statement of sceptic evenhandedness if Steve McIntyre and Ross McKitrick were to critique Briffa’s statistics. I suspect, though, that Briffa has had his work reviewed by a statistician after the easy devastation by McIntyre and McKitrick of the cooked climate science behind the hockey stick. Although Briffa, among the bunch, came off not too badly in the Climategate emails in the integrity department – he seemed to be overwhelmed by the high power, low integrity part of the “consensus” and buckled under. His reported ill health at the time may have been a factor in asserting himself against the advocacy science which was under a head of steam at the time. This paper seems to me to be one to right the wrongs the much-fiddled tree ring proxy sustained on his earlier watch, now that the consensus commanders have weakened and lost their way. Phil Jones’s post climategate statement of a 15 year warming hiatus may also point to a bit of decency and honesty in a CRU elite, but he has sadly stepped back recently on this topic by stating that 16 (17?) years of no warming is to be expected in the CAGW scheme – not seemingly aware that there are only six parcels of this amount of time in a century.
Global temperatures, past fifteen years. Another view, five different data sets.
There is no testable, falsifiable, empirical evidence showing that human-emitted CO2 has any effect on global temperature. None. There just is not any such evidence.
That means that CO2=CAGW, and even CO2=AGW, are simply conjectures. They are not hypotheses, and they certainly are not theories. They are only conjectures; opinions.
Far too much public money has already been shoveled into the pockets of these evil rent-seeking scientists. The real world does not support their scare stories. So they deviously manipulate the temperature record — GISS is notorious for its “adjustments”, which always show either a cooler past, or a warmer present. Their charts are mendacious propaganda. It is past time to stop funding these self-serving climate charlatans. The sooner their funding is cut off, the sooner we can get honesty back into science.
Friends:
I notice that at October 29, 2012 at 5:43 pm the troll remains in denial of the halt to global warming.
This would be sad if it were a mental condition instead of self-serving propaganda.
Indeed, this is the data and the assertion of it he represents.
None of the data he provides indicates a “discernible” trend. Each trend datum is within the inherent error range he presents for it.
Either he is a scientist so knows the data he provides shows that discernible global warming stopped 16 years ago or – more likely – his claim of discernible trends is a deliberate falsehood.
Richard
Briffa remains the most likely Climategate source.
richardscourtney says:
What you are trying to say is that none of the trends are statistically-different from 0 at a 95% confidence level. Of course, what is also true is that none of them is statistically-different from the post ~1975 trend of ~0.17 C per decade at a 95% confidence level. So, the claim that “global warming stopped 16 years ago” is a deliberate falsehood. There is no statistically-significant evidence to support that claim.
Jan P Perlwitz says: “There isn’t a big problem to define what a climate scientist is.”
AGW climate scientist – person who puts his/her gains (Ego, Career, Politics, Funding) above Science, Truth, Fact, and/or Honesty.
Wow you are right it was not a big problem.
😉
Jan P Perlwitz: “… unlike the temperature reconstruction in Mann et al., (1999), doi: 10.1029/1999GL900070, which was a reconstruction of the Northern Hemispheric temperature.”
Big problem in the reconstruction was based on biased data, flawed method, and ultimately cherry-picked plotting. And the bogus ideology of relating temperatures / co2 to tree rings.
Talk about your ‘Pulp Fiction’.
Jan P Perlwitz says:
October 29, 2012 at 5:43 pm
“…trends over those 16 years are discernible, even if they are not statistically significant at the 95% level.”
This is quibbling. If they are not statistically significant, then you do not even know if they exist with any reasonable level of certainty. If CO2 is warming the globe, and its relentless increase in concentration should therefore be increasing the observability of its effect higher and higher as it rises above the noise floor, then it is damned inconvenient for you to have the warming trend statistically disappear for such a lengthy interval of time.
Moreover, according to your hypothesis, the energy from the displaced warming has to be getting stored somewhere. So, it isn’t enough for you if temperatures simply resume an upward march. They’ve got A LOT of catching up to do and, you really should be honest with yourself and realize it just isn’t going to happen.
“Those trends are quite similar to the ones of another 16 year period, the period from 1980 to 1995.”
And, the overall trend across all the recorded data is the same as its been since the end of the LIA, plus or minus an additional quasi-periodic variability with a cycle time of about 60 years, which also has been in existence since the end of the LIA. There is nothing here out of the ordinary, nothing which would not be predictable without the kluge of anthropogenic forcing as a driver.
Jan writes “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 ”
Intact? Perhaps by then it will turn out to be only 0.1C warming/decade and that would be a considerable change from the dire predictions of today. Maybe less. But whatever.
The missing heat isn’t missing because its hiding, afterall we had no problems “finding” it before. Its a copout to say its hiding in an area we dont measure well (ie deep ocean). No the missing heat is missing because its simply not there and that means there is a very good chance there is no radiative imbalance at the moment warming the planet.
And that means AGW as you believe it from the models, could easily be wrong and instead the atmosphere is more efficiently transporting heat away and naturally decreasing the temperature gradient. ONLY time and data will tell and suggestions that because you’re “mainstream” and that gives your belief any credibility doesn’t wash with anyone here.
Ah come on guys, let’s cut JPP some slack. He’s one of the Kings of Climate, or at least a top lackey to one. He knows with precision the catastrophic future of the planet for a thousand years hence, that will be wrought by small variations in trace gases, as revealed by the commands given to the marvelous creations formed of silicon crystals.
Now he’s at the mercy of mere weather, a collusion of natural events that’s poised to attack what he holds dear, which can’t be comfortably predicted even a half a day away. He is powerless before the wrath of natural variation.
Thus the long drawn-out combination freak-out and distraction commentary. He’s scared, and can’t do anything about it. So he’s ranting against those who ignore what he knows has made this situation worse, that perhaps even caused it. Guess it’s just something he can do that feels like doing something.
Leif Svalgaard says:
October 29, 2012 at 3:23 pm
“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.
Leif, you are so sure of yourself.
In the meantime other papers on the topic are being published on numerous journals. And you are not able to rebut anything. As I said you only prefer slander and defamation to a real scientific debate.
Do not worry, if I am right, it will be nature to confirm my results, if I am wrong, I will be happy to be proven wrong.