the Air Vent

Because the world needs another opinion

Paleoclimate – Rotten to the core

Posted by Jeff Id on November 26, 2011

There is a lot to be said about Climategate 2 emails. Since I’ve focused so much of my time on dendroclimatology, much of the climate science I’ve studied is related to that subject.   This is in no small part due to the influences of Steve McIntyre at Climate Audit.  Often, we skeptics have made the point that trees are terrible thermometers and equally often I’ve wondered if these climatologists understand just how bad the hockey stick reconstructions are. When these issues are discussed here in the open, the believer groups usually stop by and claim that the multiple studies with same or similar results are somehow “verification” of their accuracy. The reality is that nothing could be further from the truth.

An important email because it comes from IPCC AR4 Lead Author Richard Alley makes many of the points we stand behind in one single email. This was brought to my attention by reader Kan – #3234. For the most part, emails are included in full in this post for correct context but critical parts have been bolded by me.  As a suggestion, you can read the post by skipping to the bold sections first and then checking the email for correct context.

date: Fri, 10 Mar 2006 22:50:43 -0500 (EST)
from:
subject: Divergence
to: drdendro@ldeo.columbia.edu, jto@u.arizona.edu, k.briffa@uea.ac.uk

Ed et al.–This is getting a little unmanageable in a hurry, I fear–there
are now two or three overlapping emailing lists active, and my original
words have been muddied. I am not on the committee, and I clearly
never said that I know what the committee is thinking or doing. I did say that
based on my impression of the questions asked in public by the committee (or more
properly, by some members of the committee…) that I felt that they had
some serious issues, and that I don’t expect that they will provide
a strong endorsement of the tree-ring based millennial reconstructions.
Rosanne did not emphasize the divergence problem, and sought to play it down
as something that might have several explanations but that did not upset
the basic reconstructions, so her presentation was in line with your emails.
She did show her data, and the folks in the meeting room saw the divergence
in those data.

Despite assurances from Ed and Keith, I must admit that I still don’t
get it. The NRC committee is looking at a number of issues, but the one
that is most publicly noted is to determine whether, and with what confidence,
we can say that recent temperatures have emerged from the band of natural
variability over the last millennium or two. Millennial reconstructions with
high time resolution are mostly tree-ring based, mostly northern
hemisphere, and as I understand it, some are correlated to mean-annual
temperatures and others to seasonal temperatures. The performance of
the tree-ring paleothermometry is central. Taking the recent instrumental
record and the tree-ring record and joining them yields a dramatic picture,
with rather high confidence that recent times are anomalously warm. Taking
strictly the tree-ring record and omitting the instrumental record yields
a less-dramatic picture and a lower confidence that the recent temperatures
are anomalous. When a big difference is evident between recent and a
millennium ago, small errors don’t matter; the more similar they are, the
more important become possible small issues regarding CO2 fertilization,
nitrogen fertilization (or ozone inhibition on the other side…).

Unless the “divergence problem” can be confidently ascribed to some cause that
was not active a millennium ago, then the comparison between tree rings from
a millennium ago and instrumental records from the last decades does not seem
to be justified, and the confidence level in the anomalous nature of the recent
warmth is lowered. This is further complicated by the possible small influence
of CO2 fertilization.

Ignoring for a moment the reasons for the controversy, the motivations of
some of the participants, the relative scientific unimportance
of the answer (this is about icons, not science), the implications if the
skeptics are actually right (the climate may be more sensitive than we thought,
because forcings are not revised if the thermometry is revised, so global
warming may be worse than we thought), and any other extraneous issues, I
believe that:

–There will be a lot of press and blog coverage of this issue when the NRC
report comes out;

–People will look closely at how the IPCC and NRC agree/disagree on this;

–There is a reasonable likelihood that the basic thrust of the IPCC and NRC
will agree, but that the details of wording and confidence may be somewhat
different, and that this difference could be amplified greatly by the
political process in ways that would be used to damage the IPCC.

For what it’s worth, I also am not fully reassured by the emails that have
come through.

Ed gives a very nice statement of what might have been done procedurally,
but none of this was done, the time for the committee is very tight (the report
is to be done by the time we meet in Norway, I believe…), and unless some
of you provide input to the committee, they probably have a large fraction of
their information already. (I believe that you can make statements to the
committee by email; statements will be posted on a public web site and used
by the committee.)

Keith says that the issues are complicated (undoubtedly correct),
that he has unpublished data making the case stronger, and that
“virtually all long tree-ring reconstructions that contribute to
the various reconstructions, are NOT affected by this. Most show good
coherence with temperature at local levels in recent decades.” I was just
looking at some of the recent Mann et al. papers, and at the
Osborn and Briffa paper from this year. In that one, as nearly as I can tell,
there are 14 long records, of which 2 extend to 2000, 8 end in the early to
mid 1990s, 1 in the early to mid 1980s, 2 in the early to mid 1970s, and one
in the late 1940s. That looks to be a pretty small data set by the time you
get into the strongest part of the instrumental warming. If some of the
records, or some other records such as Rosanne’s new ones, show “divergence”,
then I believe it casts doubt on the use of joined tree-ring/instrumental
records, and I don’t believe that I have yet heard why this interpretation is
wrong.

I’m open to hearing what I have screwed up. Please note, I have no direct
stake in this! I went to the meeting, I spoke, I’m done. But, I think you
have a problem coming, that it involves the IPCC and particularly chapter
6 and paleo generally, that I really should let
Susan know what is going on (if you’ve seen all the increasingly publicly
disseminated emails, you know the story). I’d rather go back to teaching
and research and raising money and advising students and all of that, but
I’m trying to be helpful. Casting aspersions on Rosanne, on the NRC panel, or
on me for that matter is not going to solve the underlying problem.

Regards–Richard

The points Richard makes are generally accurate although a case could be made for and against his sensitivity remarks.  That is a different topic though.  To sum up the points I’m addressing here- If we can’t explain divergence, we cannot delete the data and if we cannot delete the data we must question all of the tree data.

I think Ed Cook articulates the problem clearly in a very long email to Keith Briffa 3253.  This email was in Climategate #1 and was one of the more interesting emails to me.  What we have that is new though are replies from Keith Briffa in #0435 and #0643.  I’ve bolded the critical parts again below so you can read it more quickly but the email is included in its entirety for proper context.  From the emails I actually like Ed Cook, he’s not one to mince words and doesn’t allow outside pressures to influence his views. Here, he’s a little ticked at another scientist for being a know-it-all when they know full well that the uncertainties of hockey sticks are far greater than advertised.

date: Wed, 3 Sep 2003 08:32:11 -0400
from: Edward Cook <drdendro@ldeo.columbia.edu>
subject: An idea to pass by you
to: Keith Briffa

<x-flowed>
Hi Keith,

After the meeting in Norway, where I presented the Esper stuff as
described in the extended abstract I sent you, and hearing Bradley’s
follow-up talk on how everybody but him has fucked up in
reconstructing past NH temperatures over the past 1000 years (this is
a bit of an overstatement on my part I must admit, but his air of
papal infallibility is really quite nauseating at times), I have come
up with an idea that I want you to be involved in.  Consider the
tentative title:

“Northern Hemisphere Temperatures Over The Past Millennium: Where Are
The Greatest Uncertainties?”

Authors:  Cook, Briffa, Esper, Osborn, D’Arrigo, Bradley(?), Jones
(??), Mann (infinite?) - I am afraid the Mike and Phil are too
personally invested in things now (i.e. the 2003 GRL paper that is
probably the worst paper Phil has ever been involved in – Bradley
hates it as well), but I am willing to offer to include them if they
can contribute without just defending their past work – this is the
key to having anyone involved. Be honest.
Lay it all out on the table
and don’t start by assuming that ANY reconstruction is better than
any other.

Here are my ideas for the paper in a nutshell (please bear with me):

1) Describe the past work (Mann, Briffa, Jones, Crowley, Esper, yada,
yada, yada) and their data over-laps.

2) Use the Briffa&Osborn “Blowing Hot And Cold” annually-resolved
recons (plus Crowley?) (boreholes not included) for comparison
because they are all scaled identically to the same NH extra-tropics
temperatures and the Mann version only includes that part of the NH
(we could include Mann’s full NH recon as well, but he would probably
go ballistic, and also the new Mann&Jones mess?)

3) Characterize the similarities between series using unrotated
(maybe rotated as well) EOF analysis (correlation for pure
similarity, covariance for differences in amplitude as well) and
filtering on the reconstructions – unfiltered, 20yr high-pass, 100-20
bandpass, 100 lowpass – to find out where the reconstructions are
most similar and different – use 1st-EOF loadings as a guide, the
comparisons of the power spectra could also be done I suppose

4) Do these EOF analyses on different time periods to see where they
differ most, e.g., running 100-year EOF windows on the unfiltered
data, running 300-year for 20-lp data (something like that anyway),
and plot the 1st-EOF loadings as a function of time

5) Discuss where the biggest differences lie between reconstructions
(this will almost certainly occur most in the 100 lowpass data),
taking into account data overlaps

6) Point out implications concerning the next IPCC assessment and EBM
forcing experiments that are basically designed to fit the lower
frequencies – if the greatest uncertainties are in the >100 year
band, then that is where the greatest uncertainties will be in the
forcing experiments

7) Publish, retire, and don’t leave a forwarding address

Without trying to prejudice this work, but also because of what I
almost think I know to be the case, the results of this study will
show that we can probably say a fair bit about <100 year
extra-tropical NH temperature variability (at least as far as we
believe the proxy estimates), but honestly know fuck-all about what
the >100 year variability was like with any certainty (i.e. we know
with certainty that we know fuck-all).

Of course, none of what I have proposed has addressed the issue of
seasonality of response. So what I am suggesting is strictly an
empirical comparison of published 1000 year NH reconstructions
because many of the same tree-ring proxies get used in both seasonal
and annual recons anyway. So all I care about is how the recons
differ and where they differ most in frequency and time without any
direct consideration of their TRUE association with observed
temperatures.

I think this is exactly the kind of study that needs to be done
before the next IPCC assessment. But to give it credibility, it has
to have a reasonably broad spectrum of authors to avoid looking like
a biased attack paper, i.e. like Soon and Balliunas.

If you don’t want to do it, just say so and I will drop the whole
idea like a hot potato. I honestly don’t want to do it without your
participation. If you want to be the lead on it, I am fine with that
too.

Cheers,

Ed

==================================
Dr. Edward R. Cook
Doherty Senior Scholar and
Director, Tree-Ring Laboratory
Lamont-Doherty Earth Observatory
Palisades, New York 10964  USA
Email:    drdendro@ldeo.columbia.edu
Phone:    845-365-8618
Fax:    845-365-8152
==================================

Now that is quite a bombshell of an email. It is more serious than the ‘hide the decline’ situation because it gets to the heart of all of the paleo-hockeystick plots.  If you consider that they are saying any change in temps greater than 100 years in length are a complete unknown, how is it that we “know” that recent years are the warmest in history?  The very clear answer is – we don’t.

We might assume that the replies to this email were somewhat negative to a direct attack on all of paleo-thermometry but from these new emails we learned that in fact the reply by Keith Briffa was completely supportive #0435 #0643. I’ll leave the complete replies for others to locate if they want more information but the reply below from Keith Briffa should sum it up well.

ED
without the slightest doubt , I do wish to be involved in this AND/OR something like it -
what I wanted to do (to be frank) myself, is to do a piece with you, Tim and Tom Melvin and
Jan(?) , on the validity of the low frequency components of the family of reconstructions -
but with the emphasis on the tree-ring side . Tim is certainly (with me and you – remember)
doing a paper for The Holocene on the areas of uncertainty in these attempts (focusing on
calibration issues, spatial representation of predictors (spatial and time scale bias),
seasonal bias and relating these , ultimately. to the reliability of the reconstructions
{This is my version of what will be in it but he may disagree} . The basic point is that I
(and I think he) agree that Mike and Phil’s latest contribution is a step backwards ( in
time and understanding ) – well in reality I do not believe it is a step forward. I need to
read you message in detail and then phone tomorrow (I HAVE to get this PhD report off to
New Zeland now) after talking to Tim . You know I desperately want to produce a new
temperature reconstruction from the various tree-ring data (and explore the Mann western US
PC correction – though Malcolm has ignored my request for the data) . At the least , all
this requires that I come to see you (and perhaps Tim too).
I WILL be in touch ….
Keith

Just in case you are wondering whether Keith meant to agree with Ed Cook on the issue of long term variance, here is another email from Keith Briffa which restates the problem more clearly while indicating some of the pressures he is under for the IPCC report. Email #2009.

date: Thu Jan 20 10:04:49 2005
from: Keith Briffa
subject: Re: Re:
to: Edward Cook <drdendro@ldeo.columbia.edu>

Ed
will be discussing all this early next week with Gerrard. He is doing the US stuff at least
. We wish to do some longer (based on station records) stuff for some European locations
and try some reconstructions against oak data also.
I am trying to track down the NAO MSc thesis but it might be that the guy only looked at
post 1950 data – will let you know.
I am attaching the short 2000 year section from the ZOD of the IPCC report and the text of
a “box” on the MWP  (both confidential for now)
but if we can get more space , it needs expanding to cover SH and more hydro . They also
want an appendix on standardisation – so you will be involved in this also.
Really happy to get critical comment here . There is no doubt that this section will
attract all the
venom from the sceptics. I find myself in the strange position of being very skeptical of
   the quality of all present reconstructions, yet sounding like a pro greenhouse zealot here!
Told Peck that you (and Jan) will be CLAS
BEST WISHES
Keith

All present reconstructions!   It sounds to me that in private Keith and I could actually amicably discuss the issues over lunch.   In public though, it is another matter entirely. I’ve noted in the past that Dr. Briffa’s style in his published articles is to write clearly paper-disqualifying statements followed by astoundingly firm conclusions.  Now I’m understanding that this has to do with an internal battle between what he believes is true and the pressures of his job in publishing global warming papers. After all, just because we don’t really know historic temperature well, doesn’t necessarily mean we don’t know anything at all.  The big problem for paleoscience is that it might mean exactly – We don’t know! What’s more is that any closer examination of the math of the typical papers proves out the worst of the science.

“You need to pick cherries to make cherry pie”, D’Arrigo NAS panel investigation.

This sounds like an extreme remark but it is actually the standard in the field.  They actually have come to believe as a group that deleting data which doesn’t fit temperature and keeping data that does, results in a “true” temperature series.   The problem is that there are internal and external inconsistencies in what is an obviously insane approach. Non-scientific critics of this blog have often written, “Why would you keep data which doesn’t show correlation to temperature?”. This situation is a common problem in science where data is not good.  Normally you hypothesize that X is related to Y and then use stats to prove it does i.e. does cholesterol relate to heart disease. Imagine deleting the cholesterol data which didn’t agree!

In paleoclimate, the data is of such poor quality that the standard approach of using ALL of the data doesn’t work. At least it doesn’t show that there is a measurable response. Unfoutunately, what has happened in paleocliamte has been a decades long process of selecting particular series by hand and over time sorting the non-similar data such that you can average all the noise to get a reasonably temperature-looking curve in recent years. This sorting though is an unscientific nightmare caused somewhat inadvertently by the sheer mass of the government funded science.

The process I’ve described may sound too extreme to be true, but the “science” has has gone so far down this path that they have even expressed the unintended process mathematically using a very common paleo-algorithm called “composite plus scale” CPS. In CPS data is correlated to temperature and eliminated systematically such that the average of the remaining data shows a statistical correlation to temperature. I know it’s crazy sounding but there are more sophisticated algorithms as well. The problem is that all of them (100%) are forms of linear regression where individual series are weighted according to their ability to replicate measured temperature. Good looking data gets a strong weight, bad data is weakened.  Methods like RegEM, least squares, truncated least squares….on and on. Hundreds of papers processing the same data in generally the same way at enormous taxpayer cost.

Again you would be right to be skeptical of my claims. Let’s see what the scientists have to say about it #3622.

>At 06:20 AM 7/15/03 -0400, you wrote:
>>Hi Keith,
>>
>>Outdated as of June 28, 2003? Guilty as charged I guess. I’m not
>>familiar with this paper nor the authors. Of course I am skeptical.
>>In comparing my old fashioned least squares methods with advanced
>>’optimal’ methods like RegEM (that Mike is enamored with) and
>>hierarchical Bayes, there is fuck-all difference in the results.
>>Connie Woodhouse’s results with neural networks doesn’t show much
>>either over linear regression. If you are able to get a pdf, please
>>email it to me. I am not in position to get it now. Am at the beach.
>>
>>Cheers,
>>
>>Ed

There is also this extensive description of how data is selectively chosen.  It is a long email again but copied in full for context with relevent quotes bolded by me.

cc: Keith Briffa
date: Wed, 29 Mar 2006 14:36:50 +0100
from: Tim Osborn <t.osborn@uea.ac.uk>
subject: Re: Proxy time series
to: “Gustafson, Diane”

<x-flowed>
Dear Diane / Mike / NRC Committee,

At 22:18 28/03/2006, Gustafson, Diane wrote:
>Dear Tim:
>
>Our National Research Council Committee on Surface Temperature
>Reconstructions has been considering your paper with Keith Briffa
>published in a recent issue of Science.  Could you please elaborate
>on your criterion for selecting the proxy time series included in
>the analysis.  We are interested in how you computed the correlation
>between the proxy time series and local temperature time series.  Is
>the correlation based on filtered or detrended time series?  How
>would you counter the potential criticism that your selection method
>tends to favor proxy time series that show a strong 20th century warming?
>
>It would be most helpful for us if you could reply in time for us to
>consider your response at our meeting tomorrow morning.  Thanks in
>advance for your help.
>
>Mike Wallace

We (Tim Osborn and Keith Briffa) will first respond to these specific
questions about our recent Science paper.  In addition, copied below
are some further comments by Keith Briffa on issues related to
tree-ring proxy records, that may be of interest to the committee.

The primary purpose of our paper was to implement an alternative, and
possibly complementary, method of proxy-data analysis to the methods
used in most previously published reconstructions of past NH
temperature variations.  We did not want to introduce an entirely new
selection of proxy records (even if this were possible), because that
would obscure whether differences in our conclusions, compared with
published work, arose from our method or a different selection of
proxy records.

We decided, therefore, to make use of as many of the individual
records used in almost all the previously published NH temperature
reconstructions, excluding any records for which an indication of at
least partial temperature sensitivity was lacking.  So, very low
resolution records for which comparison with instrumental
temperatures is problematic were excluded.

We used records specifically from Mann and Jones (2003) and Esper et
al. (2002).  In addition we included records from Mann et al. (2003),
which I think just adds the van Engelen documentary record from the
Low Countries in Europe, because the others were already in the Mann
and Jones set.  We excluded duplicates, and our paper explains which
series we used where duplicates were present.  We did not average the
Tornetrask, Yamal and Taimyr tree-ring records as done by Mann and
Jones, because we could see no reason not to use them as individual series.

The series used by Mann and Jones had already been correlated with
their local instrumental temperatures — using decadally-smoothed,
non-detrended, values — so we accepted this as an indication of some
temperature sensitivity. For the other series, we calculated our own
correlations against local instrumental temperatures, trying both
annual-mean or summer-mean temperatures.  In our paper’s
supplementary information, we state that we used the HadCRUT2
temperatures for this purpose, which combines land air temperatures
with SST observations.  In fact, we used the CRUTEM2 land-only
temperature data set for this purpose.  These should be identical
where the proxy locations are not coastal.  For these correlations,
we did not filter the data, nor did we detrend it, and we used the
*full* period of overlap between the proxy record and the available
instrumental record.

We excluded records that did not show a *positive* correlation with
their local temperatures.  The remaining set includes most of the
long, high resolution records used by others, such as Moberg et al.,
Crowley and Lowery, Hegerl et al., Mann, Bradley and Hughes, etc. as
well as by Mann and Jones and Esper et al.

The final question, regarding the selection method favouring records
that show a strong 20th century warming trend, is a more
philosophical issue.  As stated above, we did not actually use
strongly selective criteria, preferring to use those records that
others had previously used and only eliminating those that were
clearly lacking in temperature sensitivity.  To some extent,
therefore, the question is then directed towards the studies whose
selection of data we used.  Certainly we did not look through a whole
host of possibilities and just pick those with a strong upward trend
in the last century! And we don’t think the scientists whose work we
selected from would have done this either.  There are very few series
to choose from that are >500 years long and are from proxy
types/locations where temperature sensitivity might be expected.  It
would be entirely the wrong impression to think that there are 140
such a priori suitable possible series, and that we picked (either
explicitly or implicitly) just those 10% that happened by chance to
exhibit upward 20th century trends.

The correlation with local temperature is an entirely appropriate
factor to consider when selecting data; these could be computed using
detrended data, though for those that we calculated, our use of
unfiltered data means that the trend is unlikely to dominate the
correlation.  One would need to inspect the trend in the temperature
data at each location to evaluate how much influence it would have on
the results; but in locations where a strong upward trend is present,
it would be right to exclude proxy records that did not reproduce it,
though also correct that a proxy shouldn’t be included solely on the
basis of it having the trend, especially where the proxy resolution
is sufficient to test its ability to capture shorter term fluctuations.

Finally, note that our method has not selected only those records
with a strong 20th century warming trend.  Of the 14 proxies selected
(see our figure 1), 7(!) do not have strong upward 20th century
trends: Quebec, Chesapeake Bay, W Greenland, Tirol, Tornetrask,
Mangazeja, and Taimyr.  Our method gives equal weight to all records,
so it should not be biased towards a single record, or a small number
of records, that do show strong upward trends.

Here are the additional comments on tree-ring issues:

I would also like to take the opportunity, if you will allow, to
comment briefly on some reports that have reached me concerning the
contribution made by Rosanne D’Arrigo to your Committee. Apparently,
this is being interpreted by some as reflecting adversely on the
validity of numerous temperature reconstructions that involve
significant dependence on tree-ring data. This is related to
Rosanne’s focus in her presentation on the apparent difference
between measured temperatures and tree growth in recent decades  – a
so-called “divergence” problem.
First let me make it clear that as I did not attend the Committee
meeting I am not able to comment specifically on the details of
Rosanne D’Arrigo’s actual presentation, though I am aware of her
papers with various co-authors related to this “divergence” in the
recent (circa post 1970 ) trends in tree-growth and temperature
changes as recorded in instrumental data, at near tree-line sites in
the Canadian Arctic. There are also other papers dealing with
‘changing growth responses’ to climate in North American trees.

I have co-authored a paper in Nature on the reduced response to
warming as seen in tree-ring densitometric data at high-latitude
sites around the Northern Hemisphere, increasingly apparent in the
last 30 years or so.

First, it is important to note that the phenomena is complicated
because it is not clearly identifiable as a ubiquitous problem.
Rather it is a mix of possible regionally distinct indications, a
possible mix of phenomena that is almost certainly in part due to the
methodological aspects of the way tree-ring series are produced. This
applies to my own work, but also very likely to other work.

The implications at this stage for the ‘hockey stick’ and other
reconstructions are not great. That is because virtually all long
tree-ring reconstructions that contribute to the various
reconstructions, are NOT affected by this. Most show good coherence
with temperature at local levels in recent decades. This is not true
for one series (based on the density data). As these are our data, I
am able to say that initial unpublished work will show that the
“problem” can be mitigated with the use of new, and again
unpublished, chronology construction methods.

In the case of the work by Rosanne and colleagues, I offer my
educated opinion that the phenomenon they describe is likely also, at
least in part, a chronology construction issue. I am not saying that
this is a full explanation, and certainly there is the possibility of
increased moisture stress on these trees, but at present the issue is
still being defined and explored. As the issue needs more work, this
is only an opinion, and until there is peer-reviewed and published
evidence as to the degree of methodological uncertainty , it is not
appropriate to criticize this or other work . For my part, I have
been very busy, lately with teaching and IPCC commitments, but we
will do some work on this now, though again lack of funds to support
a research assistant do not help.

The matter is important but I do not believe that the facts yet
support Rosanne’s contention, in her Global Biogeochemical Cycles
paper (Vol. 18, GB3021, doi:10.1029/2004GB002249, 2004) that an
optimum physiological threshold has been consistently exceeded at a
site in the Yukon. This conclusion should certainly not be taken as
indicating a widespread threshold exceedence.

It was my call not to “overplay” the importance of the divergence
issue, knowing the subtlety of the issues, in the fortcoming IPCC
Chapter 6 draft. We did always intend to have a brief section about
the assumption of uniformitarianism in proxy interpretation ,
including mention of the possible direct carbon dioxide fertilization
effect on tree growth (equally controversial), but it is likely to
conclude that here as well , there is no strong evidence of any major
real-world effect. This and the divergence problem are not well
defined, sufficiently studied,  or quantified to be worthy of too
much concern at this point. The uncertainty estimates we calibrate
when interpreting many tree-ring series will likely incorporate the
possibility of some bias in our estimates of past warmth, but these
are wide anyway. This does not mean that temperatures were
necessarily at the upper extreme of the reconstruction uncertainty
range 1000 years ago, any more than they may have been at the bottom.
The real problem is a lack of widespread (and non-terrestrial)
proxies for defining the level of early warmth, and the vital need to
up-date and study the responses of proxies in very recent times.

Best regards,

Tim Osborn and Keith Briffa


Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.

Ok, so we can see that there is absolutely no question that data have been preferentially selected for correlation to temperature.  I’m sure that we all agree — If you chose data which fits your conclusion, it is certain that you will find what you seek.  What is amazing is that the science has self-sorted its people into those who believe in this kind of nonsense.

On deletion of data:

Tim Osborne writes this partial email in #2346

We’re now using the MXD data set with their program and the Jones et al. data
to see: (i) if the missing data from 1856-1960 in the Jones et al. data set
can be filled in better using the MXD plus the non-missing temperatures
compared to what can be achieved using just the non-missing temperatures.  I
expect that the MXD must add useful information (esp. pre-1900), but I’m not
sure how to verify it!  The program provides diagnostics estimating the
accuracy of infilled values, but it’s always nice to test with independent
data.  So we’re doing a separate run with all pre-1900 temperatures set to
missing and relying on MXD to infill it on its own – can then verify, but need
to watch out for the possibly artificial summer warmth early on.  We will then
use the MXD to estimate temperatures back to 1600 (not sure that their method
will work before 1600 due to too few data, which prevents the iterative method
from converging), and I will then compare with our simpler maps of summer
temperature.  Mike wants winter (Oct-Mar) and annual reconstructions to be
tried too.  Also, we set all post-1960 values to missing in the MXD data set
(due to decline), and the method will infill these, estimating them from the
real temperatures – another way of “correcting” for the decline, though may be
not defensible!

First, this email makes the corruption of “hide the decline” fame is absolutely crystal clear.  It cannot be denied despite the investigations into climategate 1.0 by the august panels. Even Michael Mann vehemently disagreed with this sort of hack-stat approach.  From Real Climate:

Whatever the reason for the divergence, it would seem to suggest that the practice of grafting the thermometer record onto a proxy temperature record – as I believe was done in the case of the ‘hockey stick’ – is dubious to say the least.

[Response: No researchers in this field have ever, to our knowledge, “grafted the thermometer record onto” any reconstruction. It is somewhat disappointing to find this specious claim (which we usually find originating from industry-funded climate disinformation websites) appearing in this forum. – from Mann

In case you were wondering, everyone who disagrees with Mike is fossil industry funded.  I keep waiting for my check. You might not think that this sort of falsification would be possible in peer reviewed literature but would you be surprised to find out that this actually happened?  Email #4022:

cc: p.jones@uea.ac.uk
date: Wed Jul 20 16:58:40 2005
from: Tim Osborn <t.osborn@uea.ac.uk>
subject: Re: crowley
to: Keith Briffa, Tom Wigley

Hi Tom,
as a followup to Keith’s email, it might be quite likely that one of the series you plot is
replaced by the instrumental record after 1960, because the file from Crowley and Lowery
that is available at the WDC-Paleoclimate contains such a record.  The header states:
—————————————-
Crowley and Lowery 2000 (Ambio 29, 51)
Northern Hemisphere Temperature Reconstruction
Modified as published in Crowley 2000
(Science v289 p.270, 14 July 2000)
Data from Fig. 1, Crowley 2000:
   Decadally smoothed time series of Crowley-Lowery reconstruction
   spliced into smoothed Jones et al instrumental record after 1860
   (labeled CL2.Jns11), and a slight modification (labeled CL2)
   of the original Crowley and Lowery reconstruction to 1965.
—————————————-
The URL of this file is:
[1]ftp://ftp.ncdc.noaa.gov/pub/data/paleo/gcmoutput/crowley2000/crowley_lowery2000_nht.txt
and it is listed here:
[2]http://www.ncdc.noaa.gov/paleo/recons.html
Cheers
Tim
At 12:22 18/07/2005, Keith Briffa wrote:

as a first quick response - the Crowley numbers came from his paper with Lowery. I seem
to remember that there were 2 versions of the composite that he produced – certainly we
used the data that did not include Sargasso and Michigan site data. I presume the other
(from the CRU web site) were the data used by Phil and Mike Mann that they got from him
(where exactly did you pick then up from?)and could be the other data set (with those
sites included). It seems odd that the values are so high in the recent period of this
series and could conceivably be instrumental data , but would have to check. The scaling
of the data we used to produce the Crowley curve that formed one of the lines in our
spaghetti diagram (that we put on the web site under my name and made available to
NGDC), was based on taking the unscaled composite he sent and re-calibrating against
April – Sept. average for land North of 20 degrees Lat., and repeating his somewhat
bazaar calibration procedure (which deliberately omitted the data between 1900-1920 that
did not fit with the instrumental data (remember his data are also decadal smoothed
values). In fact , as we were using summer data we calibrated over 1881-1900 (avoiding
the high early decades that I still believe are biased in summer)  and 1920 – 1960 ,
whereas he used 1856-1880 and 1920-1965.  Of the precise details might differ – but the
crux of the matter is that I suspect one of the Figures you show may have instrumental
data in the recent period – but not ours. If you say exactly where these series came
from I can ask Tim (who will have done the calibrations) to check.
As  for the second question , the QR data are averaged ring widths from relatively few
site chronologies in the high north (mostly N.Eurasia – Scandinavia,Yamal,Taimyr),
though with a few other site data added in as stated. The 2001 data are the MXD data
from near 400 sites and provide the best interannual to multidecadal indication of
summer temps for land areas north of 20 degrees than any of the true proxy (ie not
including instrumental ) data. No idea what the correlation over the common 600 year
period is – but I have never said that the ring width is anything other than summer
temps for the area it covers .
Keith
At 20:38 15/07/2005, you wrote:

Keith,
Look at the attached. Can you explain to me why these plots
differ — particularly after 1880?
Could you also explain why the Briffa data in QR 2000 are so poorly
correlated with the Briffa 2001 data?
I think I know the answers, but I want an independent and spontaneous
answer from you.
Thanks,
Tom.


Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[3]http://www.cru.uea.ac.uk/cru/people/briffa/

Tim Osborn took this approach in #4005:

the gridding and calibration were done.  Also we have applied a
completely artificial adjustment to the data after 1960, so they look
closer to observed temperatures than the tree-ring data actually were
— don’t rely on the match after 1960 to tell you how skilfull they
really are!

Conclusion:

Climategate 2 is more interesting than climategate 1 for several reasons.  We’ve seen the infilling of several conversational lines in the original emails, numerous references to funding, corruption and information control, there is additonal reason to believe the IPCC was corrupted by political aims and the thought processes in paleoclimate are more clear.    It will take months to sort the whole thing out but in the meantime, we can understand that the core of thermometer paloclimatology is as rotten as any tree in the forest.

Readers shouldn’t imagine that the reasons for my statements are based solely on these emails. First, I’ve been at this for several years now reading papers, doing math and writing posts.  What’s more, there are so many additional emails to support my statements they would exceed anything we could reasonably put in a blog post. If you don’t think I’ve made the case, ask questions, read the emails and learn for yourself.   The whole mess is in the open now, it is up to you whether the true state of climate change science is worth understanding.

Jeff Condon – Id

143 Responses to “Paleoclimate – Rotten to the core”

  1. Steve McIntyre said

    Excellent post. Should be email 4005.

    REPLY: Thanks. I fixed the reference.

  2. thojak said

    Great post, Jeff! Plenty txs! :)

    Pointman has a very readable post on the CG2 here:

    http://thepointman.wordpress.com/2011/11/24/some-thoughts-and-some-questions-about-the-climategate-2-0-release/

    Worth while to go figuring on…

    Brgds from Sweden
    //TJ

  3. Jeff, I think you’ve come to the point where you can’t see the forest for the trees. Reading you one might get an impression that problems with tree rings invalidate all paleoclimatic reconstructions. And in the meantime:

    a) boreholes tell the same story: http://www.ldeo.columbia.edu/~peter/Resources/Seminar/readings/Huang_boreholeTemp_Nature%2700.pdf
    b) stalagmites tell the same story: http://www.ncdc.noaa.gov/paleo/pubs/smith2006/smith2006.html
    c) glacier length tells the same story: http://www.martinkodde.nl/glacier/data/bibliography/1810995712675.pdf
    d) all proxies combined — with or without tree rings — tell the same story: http://www.ncdc.noaa.gov/paleo/pubs/mann2008/mann2008.html

    I think you’re approaching a point where you have to disregard a vast majority of paleo reconstructions to be able to keep on raising doubt about them. The funniest part is that one doesn’t even need paleo data at all to prove AGW is real and dangerous.

    REPLY: Your issues should be discussed on another thread. Boreholes and stalagmites should never be used as thermometers and none of this has to do with the reality of AGW or whether it is dangerous.

  4. Steve McIntyre said

    Osborn told the parliamentary committee: “It has been argued that comments within the code such as “Fudge factor” and “shouldn’t usually plot past 1960 because these will be artificially adjusted to look closer to the real temperatures” demonstrate that data have been manipulated in an inappropriate and undisclosed manner. My programs that were highlighted on BBC Newsnight that contained comments such as these were not the basis for any published article or dataset, and thus are not a valid indication of inappropriate data
    manipulation.”

    This was one of the many issues that Muir Russell was expected to investigate, but didn’t.

  5. @JeffId

    Just out of curiosity: what are your qualifications as far as paleoclimatology is concerned? What have you published on this subject? You use a lot of strong words and very categorical judgements, one might think you must speak from very deep experience.

  6. Steve McIntyre said

    Re #3 – the reconstruction of Mann et al 2008 without tree rings relies on contaminated and upside down Tiljander sediments. Mann et al 2008 should have been retracted so that people do not innocently rely on its untrue claims. The realclimate post should have been amended to notify readers that key claims in that post were untrue.

  7. dearieme said

    “it is up to you whether the true state of climate change science is worth understanding.” That’s a very shrewd remark. When I started reading some “Climate Science” I thought I might immerse myself in it – my scientific background happens to be such that I was pretty well equipped to do so. But the more I learned, the less inclined I was to devote time to it, because so much of the work was clearly implausible stuff done by dim and incompetent workers. One beauty of the climategate releases is that they make clear that some members of the climate science gang aren’t quite as dim as their publications suggest – they are prepared to acknowledge in private that much of the work that supports their doctrine is rubbish, but they stick to the code of omerta in public. So, more crooked than I had realised at first, but a little more intelligent. Anyway, much of science depends on at least a minimal degree of trust, and this field has relinquished all claim to that, So, no, “the true state of climate change science” isn’t worth understanding – the effort wouldn’t be justified to anyone whose interests are merely scientific. Of course, they might be justified for someone whose interests are legal: there may be a case that some of these buggers are guilty of fraud in their grant applications, or in their refereeing of each other’s grant applications. A salutory jailing or two might benefit mankind. Or, for all I know, polar bears.

  8. Matthew W said

    “but in locations where a strong upward trend is present,
    it would be right to exclude proxy records that did not reproduce it,”

    =====================================================
    Is that pure dishonesty or would there ever be a valid reason to do that?

    I didn’t see an email # for this email:

    cc: Keith Briffa
    date: Wed, 29 Mar 2006 14:36:50 +0100
    from: Tim Osborn
    subject: Re: Proxy time series
    to: “Gustafson, Diane”

    Tim Osborn and Keith Briffa responding to Mike Wallace and the NRC Committee

    “The series used by Mann and Jones had already been correlated with
    their local instrumental temperatures — using decadally-smoothed,
    non-detrended, values — so we accepted this as an indication of some
    temperature sensitivity. For the other series, we calculated our own
    correlations against local instrumental temperatures, trying both
    annual-mean or summer-mean temperatures.

    ==================================================

    GIGO?? Trusting or accepting that the data is correct/valid?
    ==================================================================

    “regarding the selection method favouring records
    that show a strong 20th century warming trend, is a more
    philosophical issue”

    =============================================================
    Really??????

    For the usual suspects that are going on about “Nothing to see here”, it’s really to bad they are so biased that they can’t stand to see their heroes fall. This release of emails is a priceless look into the underbelly of the beast !!!

    Kudos to you Jeff for being able to take the time and put in the effort to have to wallow through this slime !!!

  9. Don B said

    OT–

    In climate science, it is important to have a figurehead for the Annual review.

    4127
    subject: RE: Annual review

    “Before this list, Peter asked if I could think of a figurehead for the Chair of this Board?
    I emailed my ex-colleague Jean Palutikof. Here is what she said.
    Hi Phil
    Hmmmmm…how about Bob Watson, since he’s on the doorstep.
    Apart from him, I’d mention Saleemul Huq. Works for IIED, but about to return to head on intitute in Bangladesh (but I’m sure he’ll keep strong links in UK.) Definitely a DflD darling.

    Depends just how much of a figurehead you want them to be. If totally, then maybe Joe Alcamo, now UNEP Chief Scientist, based in Nairobi. ….”

  10. [...] Jeff Id comes out and just says what we all know about Paleoclimate, even more sure than before, and so are the people who practice it. McIntyre agrees that Behind [...]

  11. Paul Linsay said

    It’s amazing that there’s no mention of plant biology at all in these discussions. There are two emails, 3219 in 2.0 and another in 1.0 where a biologist chimes in and dismisses the entire idea of a temperature/tree ring correlation. They’re ignored or screamed at. It makes you wonder if this bunch ever knew how to do science or even understand the concept.

  12. Mark T said

    I am sure the resident cheerleader thinks there is nothing to see here. I do not personally put nearly as much stock in his intelligence as the rest of you. You cannot be that ignorant without being a liar or stupid. People do not typically lie that well.

    Mark

  13. Mark T said

    Paul: there are so many problems with tree thermometer it is actually better strategy for practitioners to simply ignore it all and move on, as it were.

    Mark

  14. #6

    You’re just repeating again objections that have been shown to be invalid. It doesn’t matter in the slightest whether the Tiljander series is “upside down” or not, there’s nothing to support the claim that it’s somehow “contaminated”, and Mann’s supplementary material clearly shows that the reconstruction doesn’t change whether “problem proxies” (including Tiljander) are included or not: http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/

  15. Theo Goodwin said

    As Linsay says, the failure to mention biology is astounding. It seems that these scientists just eyeball a tree and know that it belongs in a series. When the divergence after 1960 was discovered, they should have investigated what caused it. But these scientists seem to have no empirical instincts whatsoever.

  16. Jeff Id said

    Theo,

    There is an email by a blog reader/plant biologist who points this out to the team. You can imagine he didn’t receive a welcome response.

    Craig Loehle has also published on the matter. You are absolutely right. They deliberately ignore the problem because they don’t have a solution for it.

    Grzegorz Staniak #14,

    So you are pleased with the verification stats when the series is used right side up? No problem there?
    You don’t know what I’m talking about again do you?

    Read first, write second.

    • @JeffId

      You know, Jeff, your conviction that you’re the only person in the world who knows about latewood density or EIV algorithms is sweet, but doesn’t enhance your credibility. You sound like a zaelous convert.

      Could you please answer the questions that are being asked off you? It seems you’ve just demolished the whole field of paleoclimatology: dendro is “rotten to the core”, “boreholes and stalagmites should never be used as thermometers”, and I’m sure you have an equally devastating opinion about ice core isotopes and other proxies, too. So, I just have to ask: what are your qualifications? What have you published on the subject? Can you refer me to anything more substantial than “it is so, because I say so”?

      Now, I want to take your opinions seriously. But if I do so, then you’ve just invalidated a vast majority of available paleoclimatic reconstructions. On what basis? You sound very much like someone who doesn’t have any doubts at all. How do you know that “boreholes and stalagmites should never be used as thermometers”? Pointing to low resolutions or wide error bars won’t be enough to invalidate research en masse, Jeff. So, what’s the justification of your paleoclimatological revolution here? Is there any, or have you just fallen a bit too deep into rhetoric?

  17. Stacey said

    File No 382

    I’m not sure if this is relevant? There is more.

    From: Phil Jones
    To: Tom Wigley Subject: Re: [geo] Re: CCNet: A Scientific Scandal Unfolds
    Date: Mon Oct 5 10:03:02 2009

    Tom,
    Thanks for trying to clear the air with a few people. Keith is still working on a
    response. Having to contact the Russians to get some more site details takes time.
    Several things in all this are ludicrous as you point out. Yamal is one site and isn’t
    in most of the millennial reconstructions. It isn’t in MBH, Crowley, Moberg etc. Also
    picking trees for a temperature response is not done either.
    The other odd thing is that they seem to think that you can reconstruct the last
    millennium from a few proxies, yet you can’t do this from a few instrumental series for the last 150 years! Instrumental data are perfect proxies, after all.
    [1]http://www.americanthinker.com/2009/10/un_climate_reports_they_lie.html
    This one is wrong as well. IPCC (1995) didn’t use that silly curve that Chris Folland or Geoff Jenkins put together.
    Cheers
    PhiL

  18. John F. Hultquist said

    Grzegorz Staniak @5

    Just out of curiosity, have you ever seen the movie clip wherein Richard Feynman claims that when your experiment doesn’t agree with your theory, your theory is wrong. Your insinuation (that Jeff isn’t rational enough, logical enough, or been at this long enough to make an informed statement about what is being said in these e-mails) is uncalled for. You should apologize.

    Further, in #14, you reference Mann in support of Mann. That is not the way science is supposed to be reviewed – and you know it. In any case, this post is about what is revealed in the ClimateGate 2 e-mails. If you are comfortable with what you read therein, then you might wish to give science a rest and brush up on ethics.

  19. Kan said

    From Jeff’s post –
    “This sorting though is an unscientific nightmare caused somewhat inadvertently by the sheer mass of the government funded science.”

    This a big story in these emails. Time and again you will see the push for a paper to be tilted, altered a given way in order to support some funding proposal.

    There was a very serious worry by many in the team, after Rosanne D’Arrigo gave a presentation to the NRC, that the NRC would state that tree rings were not reliable at all in the reconstructions. This would have had quite a negative impact on funding.

  20. Niels A Nielsen said

    #14
    You should get up to speed on the Tijander Issue. Even Realclimate’s Gavin Schmidt acknowledges that the inclusion/exclusion of the upside down Tijander matters. It matters to the main conclusion of the article. Read for instance this excellent article on the issue:

    http://climateaudit.org/2010/08/01/the-no-dendro-illusion/

    “nothing to support the claim that it’s somehow “contaminated””. Huh? Tijander says it is. Mann says so.

  21. Stacey said

    Jeff ID
    Thank you for putting the above in context. The email below I also posted @CA. For some reason some of my posts are in moderation?

    Please can you place the email below into context?

    Sorry this may be a double post?

    @Grzegorz Staniak
    I wonder whether some time in the past you would have wandered into a Patent Clerks office and asked him what qualifications he had?

    File No 382

    I’m not sure if this is relevant? There is more.

    From: Phil Jones
    To: Tom Wigley Subject: Re: [geo] Re: CCNet: A Scientific Scandal Unfolds
    Date: Mon Oct 5 10:03:02 2009

    Tom,
    Thanks for trying to clear the air with a few people. Keith is still working on a
    response. Having to contact the Russians to get some more site details takes time.
    Several things in all this are ludicrous as you point out. Yamal is one site and isn’t
    in most of the millennial reconstructions. It isn’t in MBH, Crowley, Moberg etc. Also
    picking trees for a temperature response is not done either.
    The other odd thing is that they seem to think that you can reconstruct the last
    millennium from a few proxies, yet you can’t do this from a few instrumental series for the last 150 years! Instrumental data are perfect proxies, after all.
    [1]http://www.americanthinker.com/2009/10/un_climate_reports_they_lie.html
    This one is wrong as well. IPCC (1995) didn’t use that silly curve that Chris Folland or Geoff Jenkins put together.
    Cheers
    PhiL

  22. Peter Dunford said

    #14

    Actually, Mia Tiljander said they were contaminated, and identified the correct orientation for use as well.

    Nice work Jeff.

  23. Jeff Id said

    Stacey,

    That has to do with Steve McIntyre’s public critique of the Yamal reconstruction right before the first email release. The Yamal series has an amazing hockey stick shape. See figure 10 at this link.

    http://noconsensus.wordpress.com/2009/11/08/the-unstoppable-dirty-dozen/

    I’ve forgotten how much work I did back then. The post is a good primer on RCS standardization as well. There is a bunch of good information on this at Climate Audit which gets into the details

  24. TGSG said

    #14

    you came to the wrong place to try to defend Mann’s repeated attempts to crawl out from under the rotting tree of his reconstructions. And in re: to your above comment about stalagmites. I don’t think error bars mean what you think they mean. According to the graph posted in your link we could be as much as half a degree cooler than the MWP and it shows NO obvious or dangerous “global climate disruption”.

    JMO, your results may vary.

  25. AMac said

    #14 Grzegorz Staniak

    [1.] It doesn’t matter in the slightest whether the Tiljander series is “upside down” or not,
    [2.] there’s nothing to support the claim that it’s somehow “contaminated”, and
    [3.] Mann’s supplementary material clearly shows that the reconstruction doesn’t change whether “problem proxies” (including Tiljander) are included or not: [link]

    Assertion #1 is incorrect. See Dirty Laundry II: Contaminated Sediments at Climate Audit. See Voldemort’s Question at AMac.

    Assertion #2 is incorrect. The authors of Tiljander03 warn about post-1720 contamination of their data series in two sections of their paper. These cautions are explicitly acknowledged in Mann08, and then ignored.

    Assertion #3 is incorrect, in that Mann08’s SI doesn’t “clearly” show anything of the sort, while Mann09’s SI clearly does show major changes result from the inclusion of the uncalibratable, upside-down, double-counted Tiljander data series (they aren’t proxies for temperature).

    Your contributions to this thread show that you are unfamiliar with the material you are discussing. You might find it useful to read some of the links that have been provided before commenting further. Further information at my website (click on my name).

  26. Stacey said

    Jeff ID

    Thanks for your reply I’ll follow the link but there’s no guarantee that I will understand it :-) Statistics was not my favourite subject when I studied for my Civil Engineering degree.

    Our Gav is having an issy fit and isn’t replying to my advances? I sent him a message but he don’t love me long time?

    Dear Gavin
    Please place the following into context without being rude.
    Regards

    date: Thu, 03 Jul 2003 21:27:32 -0400from: “Michael E. Mann” Re: Fwd: Climate Researchto: Mike Hulme p.jones wigley
    Thanks Mike
    It seems to me that this “Kinne” character’s words are disingenuous, and he probably supports what De Freitas is trying to do. It seems clear we have to go above him. I think that the community should, as Mike H has previously suggested in this eventuality, terminate its involvement with this journal at all levels–reviewing, editing, and submitting, and leave it to wither way into oblivion and disrepute, Thanks,
    mike
    At 01:00 PM 7/3/2003 +0100, Mike Hulme wrote: Phil, Tom, Mike, So, this would seem to be the end of the matter as far as Climate Research is concerned. Mike To CLIMATE RESEARCH Editors and Review Editors
    Dear colleagues, In my 20.06. email to you I stated, among other things, that I would ask CR editor Chris de Freitas to present to me copies of the reviewers’ evaluations for the 2 Soon et al. papers. I have received and studied the material requested.
    Conclusions:
    1) The reviewers consulted (4 for each ms) by the editor presented detailed, critical and helpful evaluations
    2) The editor properly analyzed the evaluations and requested appropriate revisions.
    3) The authors revised their manuscripts accordingly.
    Summary: Chris de Freitas has done a good and correct job as editor.
    Best wishes,
    Otto Kinne

  27. Carrick said

    Grzegorz Staniak :

    The funniest part is that one doesn’t even need paleo data at all to prove AGW is real and dangerous.

    There’s nothing funny about it, though the point is correct. The question you should ask yourself is, if “one doesn’t even need paleo data at all to prove AGW is real and dangerous”, why do they work so hard to get their questionable data included in the IPCC reports? And what are the consequences for the climate science community for their “hard work”?

    Climate science has chosen to own and feature the hockey stick as an icon for “dangerous unprecedented climate change”. It could only actually help them if were correctly and properly done (in a scientific responsible conduct of research way) and one of the more robust results in climate science.

    We know know, there is a lot of slop in the methods, there is a lot of shady going in the results especially in how they get presented, and “unprecedented, dangerous warming” is anything but a robust result of these day.

    You might ask yourself, given this, why they continue to feature this.

    I think the answer is because this does typify how many of the climate scientists behave in other areas, so they don’t even see anything wrong with the behavior of these scientists, and compared to the global climate modeling, it is “robust”. So really, it is an indictment on a community that is trying to foist the policy driven conclusion that “AGW is real and dangerous.” This appears to be their best evidence for it, otherwise why would they use it as a centerpiece of their arguments?

    And if it really isn’t their best evidence, you have to question the abilities of the people who’ve come to the conclusion that “AGW is real and dangerous” and wonder whether they are actually competent witnesses for the field they are trying to represent themselves.

  28. kim said

    I’m gonna have a little trouble getting anything more done today. The juxtaposition of G. Staniak’s comments #3 & #5 have disabled me.
    ==============

  29. kim said

    See? It was #5 & #14 that did it. Didn’t even see the blow coming.
    ==========

  30. Willis Eschenbach said

    Nicely done, Jeff. You have done an excellent job of illuminating a disturbing series of communications.

    w.

  31. Asdf@yahoo.co.uk said

    Gregor tries to play with the big boys. Oh dear!

  32. Carrick said

    Kim:

    See? It was #5 & #14 that did it. Didn’t even see the blow coming.

    Yes it is. Start by insinuating that if one isn’t a paleoclimatologist that one’s opinion is invalid, then go on to offer a robust defense of Mann…and get all of the details wrong.

    Ouch.

  33. Carrick said

    Maybe he was just trying to illustrate the dangers of “talking out of your a**”” instead of spending a little time critical thinking?

    Where he runs into trouble with Jeff, is Jeff backs up his comments with code to demonstrate what he says. Jeff’s distracters mostly resort to insinuation, rhetorical argument and ad hominem to do their heavy lifting for them.

  34. Dear Jeff
    What makes you think the evidence for association between dietary cholesterol and heart disease is any strong?

    http://www.ncbi.nlm.nih.gov/pubmed/22037012

    Curr Opin Clin Nutr Metab Care. 2011 Oct 26.

    Rethinking dietary cholesterol.

    Fernandez ML.
    Department of Nutritional Sciences, University of Connecticut, Storrs,
    Connecticut, USA.

    PURPOSE OF REVIEW: The perceived notion that dietary cholesterol is associated
    with increased risk for coronary heart disease (CHD) has led to dietary
    recommendations of no more than 300 mg/day for healthy populations in the USA.
    This study will review the recent evidence that challenges the current dietary
    restrictions regarding cholesterol while it presents some beneficial effects of
    eggs (an icon for dietary cholesterol) in healthy individuals.

    RECENT FINDINGS:
    The European countries, Australia, Canada, New Zealand, Korea and India among
    others do not have an upper limit for cholesterol intake in their dietary
    guidelines. Further, existing epidemiological data have clearly demonstrated that
    dietary cholesterol is not correlated with increased risk for CHD. Although
    numerous clinical studies have shown that dietary cholesterol challenges may
    increase plasma LDL cholesterol in certain individuals, who are more sensitive to
    dietary cholesterol (about one-quarter of the population), HDL cholesterol also
    rises resulting in the maintenance of the LDL/HDL cholesterol ratio, a key marker
    of CHD risk.

    SUMMARY: The lines of evidence coming from current epidemiological
    studies and from clinical interventions utilizing different types of cholesterol
    challenges support the notion that the recommendations limiting dietary
    cholesterol should be reconsidered.

  35. kim said

    Shub, an early study showed lowering cholesterol decreased mortality from cardiovascular causes but no decrease in overall mortality, which was made up for by violent deaths like homicides and suicides. I wonder, I wonder.
    ======================

  36. Layman Lurker said

    I like Cook’s email in #3253. I remember having a discussion with TTCA about some of the very points he is making IIRC. It was when we were discussing and comparing Ljungvist to Loehle. We talked about looking at centennial scale coherence of reconstructions using entire overlapping series in contrast to calibration with overlapping observations.

  37. Mark said

    Steve McIntyre said November 26, 2011 at 10:14 am
    “Osborn told the parliamentary committee: “It has been argued that comments within the code such as “Fudge factor” and “shouldn’t usually plot past 1960 because these will be artificially adjusted to look closer to the real temperatures” demonstrate that data have been manipulated in an inappropriate and undisclosed manner. My programs that were highlighted on BBC Newsnight that contained comments such as these were not the basis for any published article or dataset, and thus are not a valid indication of inappropriate data
    manipulation.”

    This was one of the many issues that Muir Russell was expected to investigate, but didn’t.”

    Steve,

    I am not sure if Dr. Kessler http://en.wikipedia.org/wiki/David_Aaron_Kessler would be willing to audit the process(s) that you noted in your post …… He was instrumental in improving the data integrity of information coming into the FDA a few years back.
    “A Perspective on Computer Validation-
    This article provides a historical review of computer validation in the pharmaceutical industry within the last three decades, evolving from the early years’ initial concept and approach to today’s current practices. Also included is how the regulations and industry have progressed in addressing the topic of computer validation.”
    located here- http://chromatographyonline.findanalytichem.com/lcgc/article/articleDetail.jsp?id=439506&sk=&date=&%09%09%09&pageID=3
    “Perspective on enforcement and observations

    “We can understand FDA concerns about computer systems as we look at the following examples. The “Therac-25″ medical-device software went awry between 1983 and 1987, overdosing patients with X-rays (21). FDA stopped the use of the device. According to the recollection of the authors, Wyeth Laboratories Inc. is believed to have received the first computer validation–related 483 from Center for Drug Evaluation and Research (CDER) in October 1983 for a lack of documentation for the validation of a computer system used for the statistical analysis of data.”

  38. From email cc: Keith Briffa
    date: Wed, 29 Mar 2006 14:36:50 +0100
    from: Tim Osborn
    subject: Re: Proxy time series
    to: “Gustafson, Diane”

    The matter is important but I do not believe that the facts yet support Rosanne’s contention, in her Global Biogeochemical Cycles paper (Vol. 18, GB3021, doi:10.1029/2004GB002249, 2004) that an optimum physiological threshold has been consistently exceeded at a site in the Yukon. This conclusion should certainly not be taken as indicating a widespread threshold exceedence.

    Well Stan, I guess JeffID, missed one of the great quotes to bold; though Jeff does know what he is banging about.

    One of the basis of temperature limitations and correlations was in a PhD area known often as Geophysical Ecology in the late 60’s and the 70’s. In this time period biologists were researching the physical reasons species and similar micro-niches existed. A common one studied was similarity of species and inter-species relationships of tundra and alpine. There were noted in the literature certain problems. I will post one of the books once I get back from vacation. Though perhaps Dr. Loehle can remember the Tall Pines (?) conferences. ANYWAY, one of corollaries of evolutionary dynamics is that species and organisms tend to exceed, reproduce, eat, etc beyond optimum. Those who know the G(y) proof that controls cannot be psychic, will realize neither can breeding, using, living, organisms. It should be assumed that species will exceed the optimum. In fact, from an evolutionary and non-psychic point of view, in general one knows that Roseanne’s and Dr. Loehle paper on temperature reconstruction compression have to be correct. In fact, in one of the first emails in CG1, first email from a sort on the word “Yamal,” the Russians state it. Indirectly of course. So, I guess, Stan if you can figure it what I am talking about and convince me that we can throw out about 20 years of research on evolutionary relationships, I will believe you. Otherwise, the fact is that Jeff’s assumptions about living systems agrees with the literature far better than Briffa et al who know this state this, and then go on to ignore it, while claiming their work has meaning.

    I know this is a tease, but then Mosher is correct; they are worse in context. In fact, if you do have professional expertise in these areas, it is even worse than the context. What they show is that they know; and then they wand wave which is nothing short of damning for their science. You do not seem to realize that they are throwing out the very scientific basis and prior work which they staked their scientific claim on.

    PS: They do not even use the correct math form for effect of temperature response and growth that was shown to be true a long time ago.

  39. Layman Lurker said

    Now, I want to take your opinions seriously.

    Puh….leeze.

  40. @Theo Goodwin #15

    Why should they mention biology? It’s not a basic research paper, they worked using thousands of proxies prepared by others. You really think they should’ve gotten into the details of dendro chronologies, sediments, ice cores, boreholes and other? Why?

  41. Stan, why take Jeff’s opinions seriously? Really!?! Take the paleoclimatologists and simply apply critical thought. They have all the authority you have claimed that should apply to Jeff, and if you understand biology, or can engage in critical thought, their comments on their own science is worse than anything Jeff could state. However, if you do know a bit about biology, ecology, and research in this area, it should be an easy task for you to show where these paleoclimatologists have erred. But then, that is a lose-lose proposition.

  42. diogenes said

    I am struggling. The mass market media are determined to hide this latest event, for whatever reasons. The blogosphere has gone wild. And there is a pattern of dedicated trollers purveying stupidity and trying to block the bloggers -here it was OPatrick (watch his inanity in evidence on Tamino) for a while and now the pitiful Grzegorz has been released from his dungeon toi try to obscure the evidence that palaeo-climate science is a mess of dingo faesces. Just what is the game being played? It makes no sense to me. Delingpole on the UK Daily Telegraph has had about 4000 responses to his blogs since the files were released…and the warmers are on toast. As Tamino, Arthur Smith, Tobis, Gavin, Steig, etc might ask…where is the science…where is the physics? The physics appears to have left them behind!

  43. diogenes said

    Grzegorz Staniak

    Have you ever heard of Death Watch beetle?

    the more noise you make, the less noise you will make in future

  44. @johnfpittman

    John, please don’t guess my name. It’s not “Stan”. If you have problems with remembering the consonant clusters, just copy&paste. You can shorten it to “Greg”, if you prefer.

    And anyway, “taking the paleoclimatologists [or any other scientists, for that matter] and simply appling critical thought” is a recipe for disaster. No “critical thought” can replace knowledge and experience. And I would expect that if you present very radical opinions without a trace of doubt (like “paleoclimate — rotten to the core”), you should have something to base them on. And it’d better be a very substantial something.

  45. AMac said

    Grzegorz Staniak,

    Don’t forget the response to three issues you raised in #14 at #25 AMac.

    Jeff has shown that he understands the wildly incorrect use of the Tiljander proxies data series in Mann08, inside and out. You challenged him on that, bringing up old Mainstream talking points… that have been retired.

    So, defend or retract.

  46. @John F. Hultquist #18

    Open any scientific journal and you’ll find masses of papers in which researchers refer the reader to their own previous work — it’s more like the rule, not an exception. The review process is meant to make sure presented arguments are sound and credible, not to remove such references. If your results are considered valid and useful, it would be absurd to deny the use of them in your future work.

    As far as my questions to Jeff are concerned, in my opinion they are justified. When you try to practically invalidate a whole field of study, you need to support the effort with something better than “because I say so on my blog” — with scientific publications, for instance.

  47. @Niels A Nielsen

    OK, point taken — they are one of the seven “problem proxies” identified in the supplement, due to the recent non-climatic influence. Which still doesn’t change the conclusions of the paper (which were based on thousands of proxies), or the conclusions based on other proxies (which Jeff is apparently capable to discard off-hand and treat as non-existent without backing it up with a shadow of an argument).

  48. Jeff Id said

    Grzegorz Staniak,

    Despite the very supportive crowd today, I don’t want to authoritatively convince you of anything. You don’t need to know what degrees I hold, you don’t need to know my background, and it doesn’t matter what I understand. The ugly truth is that this is simply a blog for the interested to consider and learn or teach. It isn’t terribly well organized, it isn’t funded at all and in reality, I don’t care what you learn. You can read and learn/teach at your will, but you have not shown the propensity to figure that out. I’ve learned climate science on line in the open. Many of the people here have taught me various things over the years.

    Watch this!

    John,

    Are there any particular books or papers from your #38 which I could find on line?

    Whether he has a reference or not, I will know more on the topic soon. In the meantime, start with RCS at Cliamate Audit and dig into a little data.

  49. kim said

    Oh, please, G; I was just recovering.
    ============

  50. Greg, sorry for calling you Stan.

    I would agree with most of your statements,but, as AMac has pointed out, you refuse to engage. Refusing to engage, makes your conversation suspect. Though Jeff may be a bit overboard in his “rotten to the core” statement, the problem is that the emails support him. You seem to either not understand this or ignore this. AND, of course, Jeff is a published author in the peer reviewed literature on the math methodology. Jeff has prefaced his claim with the math methodology. And in that respect, he meets your criteria yet you do admit it and you do challenge it without backing support.

    I would disagree with this:simply appling critical thought” is a recipe for disaster. Refusing to apply critical thinking leads to correlation is causation. I wanted you to apply critical thinking. The emails show that in private they agree with Jeff about the problems. Not that I would expect them or you to have total disagreement or agreement. But rather the starting point of discussion and reason.

    Finally, you expect that it should be a very substantial something. Actually with McIntyre and then Jeff’s peer reviewed publications as to problems with the methodology of reconstructions, it is you, not Jeff that has not fulfilled their claims. Jeff has done the substantial. Your claims to date are insubstantial. They are most often an appeal to authority, while refusing to acknowledge what has transpired. Such as Jeff is a published author on the math behind proxies.

  51. Carrick said

    John F Pittman names it:

    Take the paleoclimatologists and simply apply critical thought

    I’d advise looking up the phrase “critical thought” if you don’t know what it means, or you think you do but can’t define it, then spend some time working out how you do that.

    Remember humans aren’t born with this capacity, nor it is something you can buy, like duck tape, it’s a skill you develop over a period of time.

    Seriously, regardless of your views on climate change, if you can use this topic to sharpen that ability, something important would have changed in the world.

  52. This is all very interesting stuff but we should occasionally remind ourselves that the field of tree rings is very much ‘Deadwood’ frontier stuff, inhabited by real tobacco juice-spittin’ cowboys (i.e. the likes of Jones (a&b), Briffa, Mann etc) in comparison to ‘some other fields’ making up the ‘mountain’ of AGW.

    For example, I wait in most probably vain anticipation of some ineffably sweet day we might get to see a tranche of emails between the likes of Dana L. Royer (PhD 2002) and all his buddies and get a glimpse into the exquisitely Machiavelian antics of the ‘Florentine’ stomatal index crowd.

  53. @Carrick #27

    Sorry, but I’m not really interested in conspiracy theories. Have you got newer, better, shinier results that in your opinion should be reported by the IPCC instead? Show them.

    And lose the political propaganda language: the “hockey stick” shape as such is not particularly important, is nobody’s “icon”, and is defended simply because the vast majority of later research had it thoroughly vindicated — with centered PCA, without any PCA, without bristlecones, whatever you want. Even Wegman with his “bad science, correct results” didn’t question the results itself. Don’t tell me you’ve missed Zeke’s comparison made after Ljungqvist 2010 was published: http://goo.gl/Dfh5D — we’re now even above Loehle’s error bars. That’s what counts.

  54. Jeff when I get home, I will send you a synopsis. I doubt my education is online except as non-searchable pdf’s of old science. Though perhaps you will share with me the tickle I get when we have the alarmists talk about how old the physics of CO2 warming are while throwing out what we learned in fluid dynamics and evolutionary processes as old or older that they were all too willing to throw out.

    One of the problems with paleo constructions is that they threw out about 150 years of evolutionary theory that started with Charles Darwin’s grandfather who actually had a polemic more along the lines of modern evolutionary biology than his grandson. The problem with models are they are back in Bernoulli’s time of thermo STATICS rather than thermoDYNAMICS.

  55. diogenes said

    Grzgorz…please just give up…you are embarrassing yourself. people have stopped thinking about trying to educate you. they know that you are an indoctrinated idiot. We have seen so many of your type in the last few days on the blogs…do you really think that we do not recognise the fingerprints?

  56. #54 Greg, I must thank you for throwing out TAR and AR4. Not that I agree with you totally, but that it should make the conversation more interesting. After all, as the error bars increase, that means that the methodology of the claims and significance of the claims of anthropogenic influence and as you claimed “AGW is real and dangerous” in TAR and AR4 are incorrect.

    Perhaps Jeff, you should link the Yamal series you and I did at the time of CG1 for Greg. Greg you state “”the “hockey stick” shape as such is not particularly important, is nobody’s “icon”.”” This is categorically shown to be wrong in the TAR and AR4.

    Though, I have to admit, I don’t know if it is because you did not read the attribution, dis not comprehend what was stated, or something altogether different. But nevermind, it was TAR and AR4 that documented the IPCC’s methodology with respect to paleo reconstructions.

  57. Peter said

    Nick Stokes……Calling Nick Stokes……

  58. AMac said

    Grzegorz Staniak #54,

    I hope you haven’t forgotten the series of {Grzegorz Staniak #14, AMac #25, AMac #46}.

    I’d welcome your engagement on your three original claims in #14, and will check back later.

  59. Carrick said

    Grzegorz Staniak, what do you think a conspiracy theory is?

    I’m asking this because the way you used the word has little to do with the plain English language meaning of “conspiracy theory” with respect to my #27 comment.

    I agree with your statement that paleo reconstructions have absolutely nothing to do with AGW other than putatively answering the question “is the warming we are seeing now unprecedented”? Indeed, IMO, it makes whatever points it makes so poorly and with such a dubious level of confidence, that it should be left out of future reports. Unfortunately they’ve already “doubled down” on hockey stick graphs:

    Like it or not the hockey stick has become an iconic symbol of AGW as an “unprecedented dangerous warming”.

    That meme started with MBH98, Briffa’s heavily publicized 1999 review in Science and of course the front cover of the 1999 WMO report.

    It also makes up a whole chapter in the latest IPCC report, and they are pretty much left with whistling past the graveyard, as they continue to report, and allow reported, what are very poor quality analyses that, right or wrong, has little real bearing on the science and risk assessment of global warming.

    That it would be a previously unsurpassed public relations disaster were there to be a climate-science wide corrigendum published on paleoclimatology and its implications for AGW is itself self-evident and nor is it delving into conspiracy theories to point this obvious fact out.

  60. diogenes said

    mmm carrick…you were at the edge at post 60 of becoming an extremist nutter denialist

  61. Anonymous said

    Grzegorz,

    It seems that most of what you say is nothing more than an appeal to the authority of experts. Most puzzling. Doubting experts is a long honored (and rightly so) tradition in science, and doubting experts is science, according to Richard Feynman. Considering that most of the commenters here are practicing scientists and engineers, you might consider for moment that many here are well equipped to rationally evaluate the methodologies employed in paleoclimatology.

    I wonder, are you a practicing scientist or engineer, and if so, what is your field?

  62. Hmmm said

    The main post says: “There is also this extensive description of how data is selectively chosen”

    And then: “Ok, so we can see that there is absolutely no question that data have been preferentially selected for correlation to temperature. I’m sure that we all agree — If you chose data which fits your conclusion, it is certain that you will find what you seek. What is amazing is that the science has self-sorted its people into those who believe in this kind of nonsense.”

    What’s wrong with selecting proxy data that best correlates with the (local) instrumental record and throwing out data that doesn’t?

    Meanwhile Mann seems to keep all the data, including Tiljander, and tries to leave it to the algorithm to low weight bad correating data.

    Irregardless of which method is best surely you have to choose one of them. Either you don’t throw anything out, even very questionable data, or you remove the suspect data that doesn’t seem to represent temperature and keep only the stuff that does.

    Surely you have to do one or the other. Or am I missing something here?

  63. HMMM, you missed 3 parts.

    One, causation is not correlation;

    Two, in biology and other sciences, you propose a physical mechanism and show that the statistical model can give reasonable expectations of showing significance.

    Three, the down-weighting (or up-) of data without 2 is a circular argument.

  64. Steve Fitzpatrick said

    64..
    That is the key issue I have with most of the field. You propose a physical mechanism, you verify it (with measurements), then you use it in your reconstruction. Reaching into bowl of spaghetti, hoping to find correlations with historical temperatures, is very questionable, and may generate very incorrect results.

  65. Hmmm said

    I am not sure I understand. The post says “If you chose data which fits your conclusion, it is certain that you will find what you seek.”

    In this case they are choosing data that correlates with local temperature. So what the post is suggesting that they will (erroneously) find by doing this?

  66. Hmmm said

    “Reaching into bowl of spaghetti, hoping to find correlations with historical temperatures, is very questionable, and may generate very incorrect results.”

    I can understand that. Taking data series with no relationship to temperature and then picking the subset of that data that correlates with local instrumental temperature will produce a meaningless result. However I was under the impression that the data series that are used are somewhat influenced by temperature (eg tree rings) so selecting or weighting such data series based on how well they correlate with local temperatures seems like it would conceivably pick out, or at least err on the side of, series that actually represent temperature.

    On the face of it I am unsure whether that is sufficient to produce meaningful results, but I do notice in that link Grzegorz posted (http://rankexploits.com/musings/2010/comparing-proxy-reconstructions/) that a lot of these reconstructions agree quite well back many hundreds of years and to my mind it would be very odd if the results of each reconstruction were meaningless and yet by chance came by the same result. Assuming of course those reconstructions use somewhat different data and methods.

  67. #66, What you are missing in this case, there is data that does not fit. That is why it becomes a circular argument. Your model will not provide #2. A well documented case of this was the psychic studies at Duke U IIRC. When you took all the guesses, psychic ability could not be differentiated from random choice, but you could promote the lucky to provide a positive correlation. The methodology and discussions were at one time considered the epitome of confirmation bias creep.

  68. #67 Yes somewhat. Not independent as some claim. Also note what you yourself have stated, they low weight some data. One of the contentions is that once you compare the weightings, “dirty laundry”, they are much less independent for the most part. Those that are have been re-centered, massaged and had other tricks performed on them to show “APPARENT” not statistical similarity.

  69. Steve Fitzpatrick said

    #67,
    I think the point is the proposed proxy needs to be correlated to measurements based on a specified mechanism… that is a reasonable minimum. For example, the o16/o18 ratio in snow is based on a physical mechanism… And measurements of how water molecules with o18 behave compared to molecules with o16. Using ‘weighting’ based on compliance with historical data is very weak… It is selecting only the data which matches your expectations.

  70. #63 hmmm. The mission is to demonstrate that tree rings are proxies for temperature. Given that trees are responding to many things, including precipitation, local climate, deaths of neighbors, flooding, disease, etc, during any particular period some local populations (samples) of trees will be growing better than expected, and some worse. Given a period when temperatures trend mostly up, some groups of trees will by chance also trend up over that same period. Selecting those groups of trees to do the reconstructions will lead to a recon that looks like temperature, but only by chance. This means that as we interpret tree growth back in time as temperature, we are progressively getting randomness as a result rather than true temperature.

    A second problem is that tree line sites also tend to be dry, so the trees respond both to temperature and precip, usually in an interactive way. To reconstruct past temp for such a case we would need the precipitation history to eliminate that variable in the eqn, but we never have this info.
    For the above arguments, see my paper in ClimaticChange 2009.

    The assertion the different recons agree is false for 2 reasons. 1) many of them use the same series, and are thus not independent. 2) a recent paper looked at correlation analysis if the graphs in the IPCC spagetti graph (sorry at home right now, don’t have it handy) and found that pairs of them agreed with each other, but the clusters did not and as a whole the 11 or so curves strongly disagreed with eachother at all time scales. It is only when a forgiving human eye looks at them that agreement is there, like seeing cartoons in the clouds.

  71. AMac said

    Hmmm,

    In comment #63, raising these questions, you asked

    > Meanwhile Mann seems to keep all the data, including Tiljander, and tries to leave it to the algorithm to low weight bad correating data.

    The Tiljander data series aren’t a big part of the multiproxy reconstruction story — they are only used in Mann08, Mann09, Kaufman09, and three or four others. But their use is illustrative of the problems that Carrick, Johnfpittman, SteveF, and others are outlining.

    A robust procedure would never have included Tiljander to begin with. If it did, these data series would have been thrown out at an early stage. When outsiders pointed out that the claimed correlations of Tiljander to temperature was entirely spurious, investigators would have corrected their analysis. And they would have made clear how important their implementation of Tiljander was to the shape and validity of their reconstruction.

    Mann08 and Mann09 Fail on all these points. And yet, Mainstream science moves along, untroubled.

    Yet the problems for the paleoreconstruction enterprise run much deeper — and this may explain the comically obscurantist quality of so much Mainstream commentary on Tiljander-in-Mann08.

    For instance, it is obviously nonsensical to use a measure of 20th century lakeside construction activity as one of the key predictors of temperature back to AD 500. But it’s quite vexing to outline a procedure that would allow physically meaningful data series while excluding suspect ones — while overcoming cherry picking and confirmation bias, and without losing most statistical power through turning the exercise into a post hoc analysis (see Wikipedia for a description).

    (Mann08 and similar studies are post hoc analyses — their authors and peer-reviewers aren’t sophisticated enough to recognize this fact.)

    Tree rings aren’t lakebed varves, but they have as many and as varied shortcomings as proxies for temperature in centuries past.

  72. Carrick said

    Craig:

    The assertion the different recons agree is false for 2 reasons. 1) many of them use the same series, and are thus not independent. 2) a recent paper looked at correlation analysis if the graphs in the IPCC spagetti graph (sorry at home right now, don’t have it handy) and found that pairs of them agreed with each other, but the clusters did not and as a whole the 11 or so curves strongly disagreed with eachother at all time scales. It is only when a forgiving human eye looks at them that agreement is there, like seeing cartoons in the clouds.

    At the risk of continuing to sound like an extreme denialist nutter, I find this part the most frustrating.

    There are standard methodologies, such as Pearson’s Correlation, for determining whether two series agree or not.

    Craig probably remembers all of the acrimony his Loehle Vindication post stirred up, which related to Ljungqvist 2010.

    For example (speaking of staring at clouds), Tamino’s rebuttal. Full visual on, no statistical juju from the self-acclaimed statistics grand master, and you’re left saying w.t.f., what’s a guy got to do to get something besides obnoxious rhetoric and full-blown hand waving here?

    Prompted by a comment by the ever temperate Eli Rabbet, “DeNihilist if you look at Loehle vs Ljungqvist the correlation is not very good.
    “, I looked into this simple and obvious question: How well do they correlate with each other?

    And here’s the results.

    AD0600 to now, the series that most strongly correlates with Ljungqvist? ANS: Loehle 2007.

    For those who wonder why use correlation here: First you have to adjust for common baselines within the comparison period or the correlation coefficient gets dominated by that. Secondly, some or all methods suffer from a “loss of variance” (esp. the CPS method)…so in general I think it’s a mistake to ab initio assume they have a common scaling factor. Pearson’s Correlation adjusts for both of these by subtracting by the means of the series over the interval being tested, and by normalizing the result by the standard deviations of the two series.

    I’ll end this ramble with a comment that closed Zeke’s thread on it:

    Hu:
    Tamino is flat wrong

    Agreed. Very sloppy analysis in this case, and the only way he gets away with it is running an echo chamber with no dissenters allowed.
    As I showed above, Craig is correct that his series generally agrees with Ljungqvist, Tamino also doesn’t understand the issues well enough to recognize why the Loehle series might legitimately have a larger variance.

  73. Kan said

    Hmmm,
    ” I can understand that. Taking data series with no relationship to temperature and then picking the subset of that data that correlates with local instrumental temperature will produce a meaningless result.”

    OK, now invert this. Take a series that mostly correlates well with temperature, but it has a distinct subset that does not correlate – and you cannot explain why the subset does not correlate well.

    Can you use this series for predictive purposes? If you say yes, then you need to be able to show that the reasons/events that caused the uncorrelated subset, cannot occur during the predictive period. But you cannot do this, because you do not know the reason it is uncorrelated.

  74. steven mosher said

    #60

    what Carrick said.

  75. ikh said

    Hi Jeff,

    Thanks for a long and detailed post that is very informative.

    I have been following Steve McIntyre since about 2005 and your self only recently. Let me see if I can summarise from what I have learned over time and this post.

    Climate scientists select cores from groups of trees that are close to the treeline either by latitude or altitude. They believe that such trees growth is limited by either mean annual temperature or by summertime mean temperature. ( and they don’t mind which ). They examine a group of cores from a particular site using either tree ring density or width they try to establish a correlation between the tree rings and local temperature in the late 19thC and 20thC ( but not after 1960 ) for some value of local. If there is no correlation they discard the site. If there is some correlation ( r >= 0.1 ) Then they believe they have a temperature proxy!!!

    They never check for physical reasons why one site correlates with temp and another does not!

    I find myself forced to agree that with the current state of the art, it is impossible to use trees as temperature proxies, irrespective of whether they use valid maths or not.

    Regards

    /ikh

  76. M. Simon said

    Shub, an early study showed lowering cholesterol decreased mortality from cardiovascular causes but no decrease in overall mortality, which was made up for by violent deaths like homicides and suicides.

    “Fat” used to be synonymous with “contented”.

    Fortunately we now have “science” to actually get at the truth.

    When the global warming scare no longer proves useful we will have a return to the ice age scares – “but this time the science will be right – for sure.”

  77. trousers said

    “The assertion the different recons agree is false for 2 reasons. 1) many of them use the same series, and are thus not independent.”

    What I mean by agree is that eg all the reconstructions on that graph show temperatures drop before the instrumental period, settle on a low around 1600 and then increase back up again before that. I am not saying that they sit on top of each other – there are clear disagreements – just that the general longterm shape of what temperature has done is similar across them.

    I can understand why this might be if all of them use the same series as you say, but you say “many of them” so I wonder if some of them use different series why they still show that same general shape. If the result is highly dependent on data selection then surely it would be very easy to show completely different results by using different series? And the same goes for method too.

    In fact surely that’s the best move to conclusively show this – produce a set of reconstructions that, due to different data selection and method – produce wildly different results. What would it take to produce a reconstruction that shows a very warm 1600 for example?

  78. #78 That is one of the aspects of reconstructions that Steve McI investigated, as did JeffID on a series of postings here. There are 2 main points wrt your comment. One is that one can very different curves by removing select series meaning a claim of robust is not supported. The second is that the methods due to assumptions have similar problems with the drift and noise as one goes back in time. See post 71. As one goes back in time the signal tends to be compressed and noise levels increase both of which tend to give the straight shaft of the hockey stick. If you are unfamiliar, it is the shaft not the blade that is broken. Though the blade has had a lot of personal embellishments added to it over the years. See CA on the spaghetti graphs and other graphs.

  79. AMac said

    Trousers #78,

    Good point, very similar to one made to me by RL Smith (co-author of one of the recent attempt-at-reconciliation papers, see Ron Broberg’s post here).

    A couple of thoughts.

    1. Not only are the data series widely shared, so are the methods. Fundamentally, this involves searching for proxies that correlate to the instrumental record, 1850-on. This is generally a period of warming — combination of recovery from Little Ice Age, quasi-periodic drivings, and AGW. All data series are extremely noisy (when they include signal to begin with, e.g. Tiljander). It seems to me that calibrating to an upward ramp will lead to imputed pre-1850 temperatures that will be generally lower than c. 2000 temps. This bias could be addressed by doing a double calibration, by adding a period of downward-ramping temps, e.g. the onset of the LIA. ISTM that this would be difficult but not impossible. However, interest in ideas like this among the Mainstream is Zero, and one can see why from the discussion in this post. Dogma says that calibrating to post-1850 temps is Just Fine, so what would be the point of doing this major tranche of work? Given that it would have the likely effect of decreasing the certainty about past temps, and would be off-message to boot (“Maybe it’s not as bad as we thought.”) Would such a paper make it past peer-review at a career-enhancing journal?

    2. If one wants to characterize temperature at a given location over the past millennium or so, claiming something like “the average temp at Akron, Ohio in the 15th Century was 8.8 C (+/- 0.2 C), compared to 9.8 C in the 2000’s” — that’s informative. But reporting an average temp of 8.8 C (+/- 2.5 C) isn’t (unless we’re interested in changes on the order of Ice Ages and Eras of the Dinosaurs). IMO, the uncertainty intervals that are reported in Mainstream recons are grossly wrong — probably too narrow by an order of magnitude or more. Cherry picking (e.g. Tiljander) and unrecognized post hoc analysis are two of the reasons to suspect this. The very fact of “spaghetti graphs” implies the existence of a problem of this type. The different recons are not concordant with each other, given their stated uncertainties.

    See some of SteveF’s commentary here and at The Blackboard for his discussions of this and related subjects.

  80. I have expressed the following opiniion: Mann’s Hockeystick record [Nature 1998] stops suddenly around 1978 because it does not show the warming of the CRU (or IPCC) instrumented record.

    Can anyone support this opinion with valid proxy data?

    Thank you

  81. Sean Houlihane said

    #14 still intrigues me. Grzegorz Staniak seems like an intelligent bloke, and knows some of the background. We don’t know if he has much of a scientific background. #14 suggests he hasn’t noticed that even the emails admit that upside down is a problem, and that it clearly demonstrates how Mann seems to think that any old series which is strongly correlated in the calibration period is by the magic of statistics a good proxy.

    As I was reading the post, I was thinking – this is all very well, but what use is it? I wonder how many scientists in the field will read it, or if there is a way to condense the material down into small enough parts that the intelligent but non-specialist can start to understand that if tree rings are no good for 100+ year reconstructions then the other reconstructions need to stand alone – regardless of how well the reconstructions seem to agree.

    There seem to be two threads to follow – why the emphasis on tree rings, and what it tells us about confirmation bias in other related areas, and what the best reconstruction we can put together really looks like (after acknowledging the inconveniences of differing SST measurements and other contamination of even the instrumental series)

    For a lot of the readers here, the first thread seems to be most interesting because the 2000 year reconstruction seems so likely to be contaminated – and any alternative can fairly easily be refuted with a bit of arm waving (my spade is better than your spade, and anyway, I’ve got 10 spades which are all similar).

  82. Nic L said

    Excellent post, Jeff. Thanks for all your hard work.

  83. Thanks for the insights Jeff.

  84. dckubler said

    A search for “shenanigans” gives emails 2944 and 4253. Interesting to read Briffa proposing an “independent” audit, HIS quotes – not mine. Finally ending with –
    “We might need
    to go for a very small amount of money from DEFRA ( to pay Harry or someone
    just to manipulate palaeo data , and then after implementing the method(s)
    and deciding on the scheme, run the numerous experiments and synthesize
    results), or we may be able to do it by diverting his time from some other
    stuff anyway.
    To get the discussion going , we wish to ask your opinion(s) on the
    concept, level of interaction between us and you guys ( in planning , or
    also implementation , and synthesis, writing up?). What about this issue of
    our perceived independence – do we give a damn?
    Keith, Tim, Phil”

    Besides the faking of an “independent” audit there appears to be (at least where I worked) diversion of funds for out-of-scope task.

  85. Grant said

    The chart of proxies with 20th century instrumental temps added on show that recent warming is neither dramatic nor unusual. Of course, 20th century instrument records are not terribly accurate either. As one might expect, temps surged during the high growth period of the 50’s through the 90’s as stations became increasingly, rapidly urbanized through growth of cities and the reduction of rural stations.
    These charts are sold as being accurate when they are not. The likely truth is that we have only a general idea of temps throughout history. The next few decades will prove telling as satellites will provide us with more accurate trends in temps. They have been flat for 15 years now which is expected following 30 years of warming that began in the late 70’s.
    The crucial question is whether CO2 is dangerous at higher levels or if its effect will be small. All indications from temperature trends to sea levels indicate that there will not be a great effect.
    Is it wise to continue to grow CO2 unabated? I don’t think so but we do have the time to reduce our production in a reasonable time frame that will not impoverish or harm people.

  86. Brian Macker said

    What I’d like to see is a mea culpa from Grzegorz and ‘Hmmm’ now that their objections have been throughly addressed in the comments. I guess expecting that kind of intellectual honesty is too much to ask.

    It’s clear to anyone with a sound education in math and science that what is being done in climatology is invalid (and well accepted). It is the latter that leads to questioning of the entire field. Those who have accepted are apparent fools and those who are not critical are cowards.

  87. [...] If some of the records, or some other records such as Rosanne’s new ones, show “divergence”, then I believe it casts doubt on the use of joined tree-ring/instrumentalrecords, and I don’t believe that I have yet heard why this interpretation is wrong. [-->] [...]

  88. Red Etin said

    Jeff Id said: “Normally you hypothesize that X is related to Y and then use stats to prove it does i.e. does cholesterol relate to heart disease.”

    #34 Shub Niggurath said: “What makes you think the evidence for association between dietary cholesterol and heart disease is any strong?”

    Jeff’s illustrative point is on “cholesterol”, but Shub’s point is on “dietary cholesterol”. I’m just saying.

  89. Kenneth Fritsch said

    Jeff ID, the importance of your post is very clear and obviously shows that emaiIs amongst climate science authors point to the same problems with reconstructions as have been noted on the so-called skeptical blogs. I do, however, suggest that showing that these authors have their own doubts is not really all that important to the ongoing analyses and discussion at the non-consensus blogs. The weaknesses in these reconstructions are obvious.

    How many times have we noted that the reconstructions standing alone without the instrumental record tacked on the end are not very impressive looking and tend? over the entire period, to look more like what you would expect from a result of a time series with a long term memory. That a climate scientist will note this in a private email does not make my original observations on these matters any more valid or clear.
    What I think would be enlightening for all observers wanting to learn more about the proxies and reconstructions is to plot the individual proxies (after standardizing with the mean and standard deviation) without the interfering instrumental record and then look at the long apparent trends that one can obtain from a ARFIMA model without a deterministic trend. Obtaining an upward trend at the end can occur on a significant portion of these randomly generated model outputs. Of course, that applies to a downward trend as well and it is there that I would guess a proxy with long term memory and only little temperature response would not be used in a reconstruction. We can readily assume that temperature in recent times has a deterministic trend due to AGW and if proxy responses are mainly from long term memory or at least not responding well with temperature we would expect a divergence. I would expect that a posterior selection process would eliminate some of the divergence by a survival of only those proxies that respond “correctly” in the instrumental period, but I would also suspect that finding the “correct” proxy limits too severely the number of proxies to use in a reconstruction and some with divergence are ultimately used – or hacked off and replaced with something else.

    Some of the emails pointed to the need to bring original proxies up to current dates and correctly indicated why (divergence). That, of course, was the point of the McIntrye “StarBucks” tree ring expedition in Colorado some summers back.

  90. Tim Clark said

    As a physiologist, I could post a million references to studies like this one, on spruce trees in Canada:

    “Response function analysis indicated that (a) climate accounts for a high amount of variance in tree-ring widths; (b) tree-ring growth has significant positive correlation with mean monthly air temperature of previous October and November, and with total monthly precipitation of current January and June, while has significant negative correlation with mean monthly air temperature of May to July

    or this one in the Arizona mountains.

    Results For Picea engelmannii, Pinus flexilis, Pinus ponderosa and Pseudotsuga
    menziesii, trees in drier, low-elevation stands generally had greater sensitivity of
    radial growth to regional drought than trees of the same species in wetter, highelevation
    stands. Species low in their elevational range had greater drought
    sensitivity than co-occurring species high in their elevational range at the pinyonjuniper/
    ponderosa pine forest ecotone, ponderosa pine/mixed conifer forest
    ecotone and high-elevation invaded meadows, but not at the mixed conifer/
    subalpine forest ecotone. Sensitivity of radial growth to regional drought was
    greater at drier, low-elevation compared with wetter, high-elevation forests.
    Yearly growth was positively correlated with measures of regional water
    availability at all sites, except high-elevation invaded meadows where growth
    was weakly correlated with all climatic factors. Yearly growth in high-elevation
    forests up to 3300 m a.s.l. was more strongly correlated with water availability
    than temperature.

    The best correlated analyses show a greater response to precipitation at all temperatures, and only show a significant response to temperature when water becomes limiting. For those with impaired reading comprehension let me rephrase; water availabilty limits growth, temperature, not so much.

    But look closer at the first study. Jeff’s selected e-mails indicate (correct me if I’m wrong) that the tree proxies were calibrated to summer temperatures. Why not with the positive correlations in the fall and early winter temps???

  91. Jeff, one that I like is Geographical Ecology: Patterns in the Distribution of Species by Robert H MacArthur Harper and Row 1972. One of the interests for proxies, a synopsis: One of the metadata one would like to look at is that a 3F cooling of elevation on a moist mountian is about 100 miles of lattitude and is often called Hopkin’s bioclimatic law. One of the discussions “The Failure of Climate Alone to Account for Species Distribution.” Or how about “History or Equilibrium: The Principles of Equal Oppurtunity.” “The Machinery of Competition and Predation.”

    I will look up a typical temperature relationship at work.

  92. Kenneth Fritsch said

    The D’Arrigo/Wilson paper linked below is a summary of the divergence works and lists most of the conjectures for explaining divergence in MXD and TRW growth in the 1960s to current time. I found it interesting to note that Wilson points to a posterior selection process that gives a better response from tree rings to latter 20th century temperatures. What rather confounds me is that if I have sufficient proxies to select from I would not be at all surprised to see that I could select some that appear to respond well to temperature, since I know that I can do the same with selected random responses from ARFIMA and ARIMA models.

    http://www.ldeo.columbia.edu/~liepert/pdf/DArrigo_GPC2007.pdf

    “Wilson et al. ( submitted) hypothesized that the use of “divergence-free” chronologies (at local/regional scales) may be the only way to develop large-scale, valid temperature reconstructions through the recent period. Figure 5 presents a new temperature reconstruction for the Northern Hemisphere (hereafter WNH2006) that utilizes 15 (see Figure 4A for locations) tree-ring based proxy series that express no 1 divergence effects, based on modeling with local gridded data (Wilson et al. submitted). WNH2006 extends from 1750-2000, is completely independent from previous Northern 3 Hemisphere temperature reconstructions (i.e. no data overlap), and was developed exclusively to test whether a “divergence-free” Northern Hemisphere temperature reconstruction could be derived if appropriate unbiased (i.e. showing no divergence at the local scale) tree-ring proxies were used. It should be noted, however, that this “divergence-free” reconstruction includes sites at lower latitudes than the more typically northern treeline locations used in previous reconstructions.”

    In the link also we see the following excerpt which reminds me of the all the parameter tuning available to those intent on getting “good” calibration results. What is never shown is what happens if I use June-Aug or May-July data. I have seen Wilson models where he apparently selects arbitrarily the period for calibration and the combinations of TRW and MXD growth. Notice in the link below the local temperatures are apparently not used – and thus we can tune by selection of regional temperature. Interesting that we do not see clearly what happens when other periods are used nor an explanation for using the period that appears in the publications – the so-called missing sensitivity tests.

    “If WNH2006 is calibrated against extra-tropical (20-90°N) May-August maximum temperatures, no divergence is noted over the recent period (Wilson et al. submitted).”

    But, of course, what so-called skeptics have long called for here was an a priori selection process for proxies that was founded on some rational physical grounds and then looking at the relationship of temperature to proxy response.

  93. Kenneth Fritsch said

    It should also be noted that in the index Wilson shows only the reconstruction and not the contributing proxies. What is always illuminating is what those individual proxies look like and howm different the proxy often are from one another. The Wilson divergence free reconstruction appears to have some divergence and a lower trend than the NH temperatures.

  94. Blog Lurker said

    #81 S. Fred,
    I don’t think it’s as simple as that. Most of the proxies (esp. the ITRDB tree rings) Mann et al. used for MBH98/99 DID actually finish in the 1970s/80s.
    That’s not necessarily their fault.
    For tree rings, I gather there was a lot of work done by dendroclimatologists, e.g. Schweingruber, in the 1970s/80s, and not as much since.
    Have a look in mbh98datasummary.txt in the SI for their 2004 corrigendum for some details on the proxies used.
    McIntyre has some further details on the proxies at: http://www.climateaudit.info/data/network.details.txt
    So, I think that’s the simple answer to your specific question.

    Now, you might well ask what those tree rings (& other proxies) show now. That’s a good question.
    McIntyre asked something similar back in 2005 in a post called “update the proxies” or something like that.
    He later decided to do his own updating for Almagre. Have a look on his site for the “Starbucks hypothesis”.
    Also, look for posts on Ababneh’s update for Sheep Mountain, which she did as part of her PhD, but never officially archived.

    You have to remember that many paleoclimatologists consider their job as “extending the instrumental record”.
    They either implictly or explicitly believe that the instrumental record is perfect. Perhaps because of confirmation bias?
    This is why, when the proxies don’t show the same trends as the instrumental it is assumed that the proxies are at fault.
    I’m guessing you are questioning that assumption, correct?

    Well, getting back to your question, I don’t know that Mann et al. deliberately stopped their analysis then because of a divergence.
    To be honest, I think they were just out of their depth, and too excited by their results to check if they were real or not.
    That doesn’t justify their reluctance to acknowledge their mistakes, and lambast all their critics, since then, though.

    However, other groups – Briffa et al., D’Arrigo et al., etc have noted a “divergence problem” for tree rings.
    I think this is what you were getting at, no?
    Some groups have tried to find trees that don’t have that “problem”, i.e., ones showing almost continuous growth for the entire 20th century. If they do, then they assume it MUST be because of “global warming”… Of course, most of these have a “hockey stick” shape, e.g., Briffa’s Yamal chronology.
    If you use these then your estimate will continue to show unusual global warming. Hence, the popularity of Yamal, etc.

    Of course, you probably should ask whether Yamal’s odd growth is truly temperature-related or not…
    But, it’s easier to just plug it in and get your very own hockey stick to add to the pile of “independent” studies… ;)

  95. John Skookum said

    These comments, especially those of Mr. Hmmm, bring to mind an old scam used by professional touts who sell their predictions of horse races to gullible gamblers. They will commonly mail (or nowadays, email) unsolicited free predictions to a very large number of gamblers (their “marks”) over multiple weeks, to allow them to place their own bets and thus “prove” to themselves that the tout has some can’t-miss inside dope on the ponies and jockeys.

    What they don’t tell their victims is that each individual subset of predictions is different for each mark, tailored so that their entire set of predictions will encompass most plausible results. Each week, 25% or so of the marks will win, while the rest lose their money. The next week, 25% of last week’s winning 25% will win big again, and so on.

    After three or four iterations of this, there will be a tiny fraction of their marks who will be gratefully astonished at how accurate their tout’s predictions are, and for another few weeks they will happily re-invest their winnings in paying a very high price for the tout’s predictions on upcoming races. (The alarmists and their rapacious government cronies have that part particularly well understood).

    So what if nine hand-picked pine trees in Yamal show an amazing correlation with temperature, and neatly dispose of the Medieval Warming Period, and predict catastrophe if we don’t change our wicked carbon-spewing ways? The onus is on the alarmists to show me a much larger set of dendrochronology results from the same locality and elsewhere, and give a plausible explanation for how they are to be included in or excluded from analysis. Otherwise, the default assumption must always be that they are cherry picking their results from statistical noise and local conditions. And by God do these emails ever confirm it!

  96. #25 AMac

    OK, I’ve read up on this a bit, and this is what I gather:

    i) the data series from Tiljander 2003 are in fact strongly contaminated by non-climate signal from the 18th century on, and are therefore not calibratetable against the instrumental record,

    ii) this creates a problem by introducing a spurious signal in the analysis,

    iii) Mann’s response (http://www.pnas.org/content/106/6/E11.full), while technically correct in the description of the method, doesn’t acknowledge the problem resulting from the point i).

    So yes, I was wrong, and Jeff was right, on points a) and b).

    I still don’t see why the figures 7a/7b in the supplement are not an illustration that Tiljander or no Tiljander (or rather: problem proxies, or no problem proxies), the recontruction stays practically unchanged.

  97. kim said

    You’ve got to watch the pea under the bristlecone tree.
    ============

  98. AMac said

    Grzegorz Staniak #97

    I concur with your i) and ii). I don’t see any sensible contrary arguments (though many candidates have been proffered).

    iii) As well as not addressing the problems it purports to, Mann’s response isn’t technically correct. It could be considered partly-correct, if one wishes to celebrate sharp practice.

    > I still don’t see why the figures 7a/7b in the supplement are not an illustration that Tiljander or no Tiljander…, the recontruction stays practically unchanged.

    Sharp practices again. This is addressed in this AMac post and more fully in this ClimateAudit Post. The fundamental interpretive problem is represented by a series of cartoons in this AMac post.

  99. AMac said

    Grzegorz Staniak #97

    Thank you for the response.

  100. #51 Johnfpittman

    Unfortunately, I have a job and a life that keep getting in the way when I need to spend time reading or browsing the web. Hence the bursts of activity, and this particular thing had to wait for the next burst after I finished browsing.

    I was mistaken on at least two points out of three as far as the Triljander data series are concerned. Still, I fail to see the importance of a marginal error which didn’t influence the results of the reconstruction, which have been confirmed since by other reconstructions.

  101. #51 Johnfpittman

    Just two more things: expertise in mathematics doesn’t really translate into expertise in climate science — and vice versa. If you consider references to published literature on the subject to be “appeal to authority”, then science as a whole is one great appeal to authority. Where can I find references to the papers published by Jeff?

  102. #57 Johnfpittman

    Please refer me to the parts of TAR and AR4 that you have in mind (the ones that show the “iconizing” of the hockey stick).

    I must say I don’t really understand the main premise of your argument here: the AGW theory in no way depends on the error bars of any paleo reconstructions. And neither do assessments of its consequences, which are mostly based on existing empirical evidence: you can’t disappear melting glaciers, changing seasonal patterns or migration of species by raising doubts about Mann et al. 2008.

  103. #65 Steve Fitzpatrick

    Just out of curiosity: what physical mechanism do you suggest as the source of the warming observed for the last 40 years?

  104. AMac said

    Grzegorz Staniak #101

    > Still, I fail to see the importance of a marginal error which didn’t influence the results of the reconstruction, which have been confirmed since by other reconstructions.

    This is incorrect. See the links in #99 supra.

  105. #82 Sean Houlihane

    Two points:

    1) [T]ree rings are no good for 100+ year reconstructions: actually, good or no good, it’s not “tree rings” — it’s “high latitude northern hemisphere conifer rings”, if you’re talking about the divergence problem. And even then not all of them.

    2) why the emphasis on tree rings: who exactly is putting all the emphasis on tree rings? Here’s a quotation from TAR:

    http://www.grida.no/climate/ipcc_tar/wg1/068.htm

    Several important caveats must be borne in mind when using tree-ring data for palaeoclimate reconstructions. Not least is the intrinsic sampling bias. Tree-ring information is available only in terrestrial regions, so is not available over substantial regions of the globe, and the climate signals contained in tree-ring density or width data reflect a complex biological response to climate forcing. Non-climatic growth trends must be removed from the tree-ring chronology, making it difficult to resolve time-scales longer than the lengths of the constituent chronologies (Briffa, 2000). Furthermore, the biological response to climate forcing may change over time. There is evidence, for example, that high latitude tree-ring density variations have changed in their response to temperature in recent decades, associated with possible non-climatic factors (Briffa et al., 1998a). By contrast, Vaganov et al. (1999) have presented evidence that such changes may actually be climatic and result from the effects of increasing winter precipitation on the starting date of the growing season (see Section 2.7.2.2). Carbon dioxide fertilization may also have an influence, particularly on high-elevation drought-sensitive tree species, although attempts have been made to correct for this effect where appropriate (Mann et al., 1999). Thus climate reconstructions based entirely on tree-ring data are susceptible to several sources of contamination or non-stationarity of response. For these reasons, investigators have increasingly found tree-ring data most useful when supplemented by other types of proxy information in “multi-proxy” estimates of past temperature change (Overpeck et al., 1997; Jones et al., 1998; Mann et al., 1998; 1999; 2000a; 2000b; Crowley and Lowery, 2000).

    And here’s AR4 on the same subject:

    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch6s6-6.html

    [...] Changes in proxy records, either physical (such as the isotopic composition of various elements in ice) or biological (such as the width of a tree ring or the chemical composition of a growth band in coral), do not respond precisely or solely to changes in any specific climate parameter (such as mean temperature or total rainfall), or to the changes in that parameter as measured over a specific ‘season’ (such as June to August or January to December). For this reason, the proxies must be ‘calibrated’ empirically, by comparing their measured variability over a number of years with available instrumental records to identify some optimal climate association, and to quantify the statistical uncertainty associated with scaling proxies to represent this specific climate parameter. All reconstructions, therefore, involve a degree of compromise with regard to the specific choice of ‘target’ or dependent variable.

    and also, with reference to the consequences of the divergence:

    In their large-scale reconstructions based on tree ring density data, Briffa et al. (2001) specifically excluded the post-1960 data in their calibration against instrumental records, to avoid biasing the estimation of the earlier reconstructions (hence they are not shown in Figure 6.10), implicitly assuming that the ‘divergence’ was a uniquely recent phenomenon, as has also been argued by Cook et al. (2004a). Others, however, argue for a breakdown in the assumed linear tree growth response to continued warming, invoking a possible threshold exceedance beyond which moisture stress now limits further growth (D’Arrigo et al., 2004). If true, this would imply a similar limit on the potential to reconstruct possible warm periods in earlier times at such sites.

    This hardly sounds like a biased approach to me. And the general answer to the question “why are they even trying” is simple: because tree rings provide annual/seasonal resolution. It’s tempting to try to squeeze climate signal out of them.

  106. #87 Brian Macker

    It’s clear to anyone with a sound education in math and science that what is being done in climatology is invalid.

    No, it definitely isn’t. I can get you in touch with skilled physicists who’ll contradict your opinion.

  107. kim said

    G, you still don’t get it, though AMac tries yet again in #105. Mann’s reconstructions always seem to have bad proxy series. He fooled you by showing one with Tiljander but without the split bark bristlecones, and one without Tiljander but with the split bark bristlecones. You can find this sharp practice pea hiding under the shells in all his work.

    What do you suppose is the cause of the warming for the last 150 years?
    ====================

  108. #91 Tim Clark

    The best correlated analyses show a greater response to precipitation at all temperatures, and only show a significant response to temperature when water becomes limiting

    Perhaps that’s why one of the steps in preparing chronologies for showing the temperature signal is choosing a temperature-sensitive species in a temperature-limited location.

  109. #108 Kim

    I’ve seen this argument, but as long as I don’t have a convincing argument why split bark bristlecones series should be evil, I don’t see the reason for excluding them from any reconstruction. Otherwise, you could always find a series that a reconstruction particularly relies upon and demand its removal to disqualify the reconstruction. “Problem proxies” — OK, but I can’t see the reason for comparisons with “no dendro and no Tiljander”.

  110. Jeff Id said

    Grzegorz,

    You have quoted a sentence and assumed the rest. Again, I find that you won’t ask why we can read a sentence like that and tell you that it doesn’t address the issue. Do you really think I/we haven’t read that stuff? Here is my favorite quote from Mann08:

    Because of the evidence for loss of temperature sensitivity after 1960 (1), MXD data were eliminated for the post-1960 interval.

    Can you guess why?

    You don’t get to eliminate data which doesn’t support your conclusion. You can eliminate types of data but dendrowhackology eliminates based on directly calculated correlation. Even series which sit right next to each other might be used or not based on correlation to the expected result. Since there are so many kinds of tree response, what makes anyone know how they respond now is the same as they did in the past? What makes the chance of correlation to temp actual proof that it correlated in the past? What makes the correlation to temp of short variances, mean that we can see the long ones? And just to finish what is probably not going to be considered, what makes correlation to temp indicate a ‘linear’ response to temp.

    It ain’t sane dude.

  111. AMac said

    Grzegorz Staniak #110

    > I can’t see the reason for comparisons with “no dendro and no Tiljander”.

    See the links in #99 supra.

    Mann08 was published in PNAS, one of the highest-impact peer-reviewed journals on the planet. Why did Mann et al. think their work was important enough to submit there? What was it about their claims that made the peer-reviewers and editors agree?

    When you can answer this question, you will also have the answer for why the “no dendro/no Tiljander” comparison is one of the keys to the paper.

    Again, see the links in #99 supra.

    Unfortunately for Mann08’s authors and advocates, “key to the paper” means “the central conclusions of the paper fall apart.” This would be the case even if other aspects of Mann08 were good science. Which they aren’t. Search this blog for Jeff’s analyses of the paper’s methodologies.

    The scientific literature is full of mistake-ridden papers with invalid claims. In few other fields are mistake-ridden papers with invalid claims defended tooth-and-nail by the Mainstream establishment. What makes climate science so different?

  112. Layman Lurker said

    I’ve seen this argument, but as long as I don’t have a convincing argument why split bark bristlecones series should be evil, I don’t see the reason for excluding them from any reconstruction. Otherwise, you could always find a series that a reconstruction particularly relies upon and demand its removal to disqualify the reconstruction.

    This statement is laughable. Why are you all even bothering with this guy?

  113. Jeff Id said

    LL. That’s a good question. I think it is nice to get a different opinion once in a while but the really silly stuff is hard to justify. Regarding the bristlecones, there is a lot which could be discussed regarding PCA but I don’t think our target audience is ready.

  114. steve fitzpatrick said

    Grzegorz #104,

    what physical mechanism do you suggest as the source of the warming observed for the last 40 years?

    Mostly GHG forcing, and I have never suggested otherwise. You seem still to be searching for straw men to knock down. The substantive technical issues related to uncertainty in Earth’s sensitivity to radiative forcing have nothing to do with the accuracy of radiative physics.

  115. kim said

    Steve, what do you think is the cause of the warming for the last 350 years? CO2? Yeah, could be. Could be vice versa. Tell me who knows?
    ==========

  116. Blog Lurker said

    Greg #97,#110:

    Mann et al. appeared to have carried out a couple of sensitivity tests, and I think most people here would agree that it was a good idea. My main problem with that specific point is that he was bizarrely selective in the tests. Two main groups of proxies out of his 1029 (or thereabouts) had been specifically discussed as highly problematic. Tiljander et al. had specifically highlighted the post-1720 portion of their proxies as contaminated. So, that was ONE group whose use was highly questionable. But, the other group was the bristlecone/foxtails. McIntyre had spent years highlighting Mann et al., 1998’s use of them as one of his biggest complaints, but there has been quite a bit of discussion elsewhere on them.

    Whether you believe the bristlecones/foxtails used by Mann et al. are a useful proxy or not, it should be obvious that they are at least proxies with “a potential problem”, i.e., deserving of sensitivity analysis. Mann should have been acutely aware of the controversy, as it was one of the main points he was criticised over… even going back to Briffa & Osborn, 1999 (hardly guys you would call “climate sceptics”!).

    So, yeah, it’s true you could (and probably should) have a valid debate over every one of the proxies, but these two particular groups should have been immediate “red flags”.

    His choice to limit his analysis to “no-Tilj” or else “no-tree rings” was bizarre. When they finally did the “no-Tilj, no-tree rings” analysis, most of the reconstruction broke down, i.e., it failed the sensitivity tests. You could argue that that was because the no-Tilj, no-tree rings subset was too small. Sure, but why not do the no-Tilj, no-bristlecones???

    Compare that for instance to Jeff’s sensitivity analysis for Ljungvist, 2010: http://noconsensus.wordpress.com/2010/10/16/robust/

    Greg #104:

    I know you were responding to comment #65 there, but it is worth noting that all of the multiproxy estimates have difficulty in reproducing the same recent warming that the weather station estimates suggest… even with cherry-picking of proxies. That suggests several possibilities:
    1. there are problems with the weather station estimates
    2. there are problems with the multiproxy estimates
    3. many of the proxies show a limited response to “strong warming”.

    If 1 applies, then this suggests that the recent warming may not have been as strong as is currently thought.
    If 2 applies, then all of the attempts to put the weather station estimates into the context of the last millennium or so may be compromised.
    If 3 applies, then it is plausible that the same could have happened during earlier pre-instrumental periods, e.g., the “Medieval Warm Period”.

    In terms of man-made global warming theory, do you see that if any of those possibilities are true it has implications for how much (if any) of the recent climate change is related to CO2 changes?

  117. [...] Jeff Condon of Air Vent produced a tour de force post on how the climate scientists fell into this trap of seeing past temperatures in noisy tree ring data. It is a long and detailed post, but it hits the nail on the head. The most important ting to  know is that tree ring data is first selected based on how it tracks with temperature. All those tree rings that don't track are thrown out. This comes under the fancy name "detrending", but is known to the layman as 'cherry picking': Now that is quite a bombshell of an email. It is more serious than the ‘hide the decline’ situation because it gets to the heart of all of the paleo-hockeystick plots.  If you consider that they are saying any change in temps greater than 100 years in length are a complete unknown, how is it that we “know” that recent years are the warmest in history?  The very clear answer is – we don’t. [...]

  118. Brian H said

    Re: Kenneth Fritsch (Nov 27 19:27),
    … or if not “a priori”, at least treating the “selected” records as the basis for an hypothesis, which would then be tested on other randomly chosen similar proxies. Self-testing is tautologous incestuous circular question-begging fakery.

  119. #111 JeffId

    Are you serious? There’s an answer included in your question: “because of the evidence for loss of temperature sensitivity after 1960″. Are you gonna clutch at “hiding the decline” like the last straw? Why shouldn’t anyone take into account a problem identified a decade before and acknowledged in hundreds of papers?

    “You don’t get to eliminate data which doesn’t support your conclusion”
    Really? You don’t get to discard data coming from a broken instrument? Then you should be protesting e.g. the UAH series, so far it consists of continual adjustments and corrections, some of them not justified at all.

  120. Jeff Id said

    #119

    You have answered none of my questions. Last chance. How do you know the instrument is broken?

  121. Blog Lurker said

    #119 Grzegorz,

    1. Are you familiar with this problem: http://en.wikipedia.org/wiki/Overfitting ?
    2. See my response in #117 to #104.

    Does that help?

  122. John M said

    “How do you know the instrument is broken?”

    More importantly, if the claim is that the “instrument is broken”, how do you know it wasn’t broken hundreds of years ago?

  123. j ferguson said

    “More importantly, if the claim is that the “instrument is broken”, how do you know it wasn’t broken hundreds of years ago?”

    How do you know it wasn’t always broken.

  124. Jeff, you need to condemn Grzegorz Staniak by his own words. He says:

    “”Why shouldn’t anyone take into account a problem identified a decade before and acknowledged in hundreds of papers?”” Well, they should; and should acknowledge that an answer to the problem was not identified, which means Jeff’s objections are STILL meritorious.

    He says: “Really? You don’t get to discard data coming from a broken instrument?” The real point that Jeff is making is that the methodology is from a broken set of assumptions that nullify the conclusion. This failure of methodology is much worse and is insurmountable, where as Grzegorz correctly points out data MAY BE correctable for a broken instrument, but not necessarily true.

    Grzegorz, you do realize that your claim of discarding data is contingent on knowing it is broken, rather than the methodology that determines whether it is broken or not, is actually the part that is broken?

  125. Blog Lurker said

    John, agreed. But, don’t give up just yet. I think Greg believes we are deluded, because we are not impressed by the circular arguments of Briffa, D’Arrigo, Mann, et al. ;)
    But, do we really want Jeff’s blog to be just read by people who already agree with him? :(

    Remember, he’s outnumbered here. I know he seems to be ignoring everything we’re saying. But, he has taken some of what we’ve said on board, e.g., some of AMac’s comments. I would like if he could see where we’re coming from. I don’t mind if he still disagrees with us then.

    Ok, I’m going to try again. Greg, please let me know if this helps. (and if any of the others disagree, please contradict me)

    ————-

    For me, the key point is that the “temperature proxies” are NOT substitutes for thermometer readings. The likes of Mann et al., seem to believe that they can use them as an “extension” of the instrumental records. That is scientifically nonsense. And, I think this is the main source of the disagreement.

    What we CAN (possibly) do is to construct a temperature model from the proxies by fitting the proxies to the instrumental data. In the article I linked you to, the instrumental data is our “training data”.

    This is where the “overfitting” problem I mentioned comes in – you can’t just throw a pile of “proxies” in & select the ones that match the “training data”, and you certainly can’t cut off part of the proxy data which doesn’t fit the training data!
    Because, IF you end up overfitting, then your model is ONLY of value in the training period. In other words, it tells you nothing about temperatures before the instrumental record.

    But, here’s another crucial point:
    Even if you’ve got a good model, it still cannot be used as a substitute for the instrumental data. You can only use the model for comparing one model temperature to another model temperature

    If your model has limits to its sensitivity, e.g., has a divergence “problem” in the training period, then you have to assume it could have had those problems before! As J Ferguson asked, “how do you know it wasn’t always broken”?

    By the way, this means that you cannot compare the Medieval Warm Period maximum of the Mann et al. 2008 model to the instrumental maximum of the 20th century, just to the 20th century model maximum.

    Do you see what I mean?

  126. Carrick said

    Jeff ID:

    How do you know the instrument is broken?

    In Grzegorz’s case, based on whether you get a hockey stick or not. Whether he understands that is the case or not depends on how self-aware he is.

  127. Jeff Id said

    “But, do we really want Jeff’s blog to be just read by people who already agree with him? ”

    This blog is just big enough that the UEA guys stop by. Those who read and those who comment are different. this used to be a lot bigger blog when I was regularly writing. Right now I’m so disgusted it is hard to care. Still I would say that this blog is in the top 1000’th percentile for the abilities of the typical blog commenter. Try and say something which you can’t defend. Personally, I don’t get away with it any better than Grzegorz.

  128. Jeff Id said

    Actually, to make this fun, all of the climate dept at UEA knows and checks this blog. That is who we are talking to when we comment. No they aren’t checking every day but when their day jobs aren’t too pressing, they stop by and check what is happening. The same is true for the RC boys. When I write to the RC crowd about my latest complaint, they are aware of it,

    There is enough science here to make our opinions dangerous to the consensus, what makes it worse is our lack of care which message gets sold.

    I really don’t give one tiny shred of a care which way AGW falls. Nobody else should be either. Science doesn’t care which way the ball drops. I do care about spin and overselling your message. In fact, I am ridiculously frustrated with climatoknowledgists at this point.

    Carrick, Roman, Kenneth, Lurk, Ryan, John P, Nic, Lucia, Steve F, Steve M’s and endless others here are very good at what they do. If Greg wants to mess with them, good luck to him. If G gets serious, I’m going to watch spongebob with the kids until the mess is over.

  129. Carrick said

    SteveF:

    Mostly GHG forcing, and I have never suggested otherwise.

    My back-of-the-envelope numbers suggest the most probable value is 2/3 of the warming for the last 40 years is AGW, but not all of that is purely due to woCO2.

    I think it would be fair to say that I’m more sold than Steve that anthropogenic aerosol forcings are an important if poorly understood climate forcing, and think that cutting back on them starting in the 60s resulted some of the “delayed warming” to appear from 1980-2000.

    I think sitting on top of that is the 60-year cycle that people like to talk about (and it is starting to trend negative.

    These numbers certainly put the climate sensitivity on the lower end, but as I’ve said otherwise, the right way to do science is to consider first the best methodology, implement it as well and impartially as you can, and only then “lift the lid” and see what it’s implications are.

  130. phi said

    Blog Lurker #126,

    “For me, the key point is that the “temperature proxies” are NOT substitutes for thermometer readings. The likes of Mann et al., seem to believe that they can use them as an “extension” of the instrumental records. That is scientifically nonsense. And, I think this is the main source of the disagreement.”

    What one seeks to know, is essentially the evolution of regional mean temperature. To my knowledge no one has shown that MXD was worse than stations thermometers for that.

  131. Blog Lurker said

    Jeff #129,

    Interesting to know. :) And, I agree you’ve been more than patient – I don’t know if I would be as patient as you’ve been if it was my blog. But, I would like if Greg could at least understand the basis for our arguments. He can disagree with them afterwards if he likes.

    Also, I totally agree that “Nature” doesn’t care what we think it’s supposed to do. That’s part of the reason I’m frustrated that the IPCC chose to go with computer models rather than experiments for their “detection & attribution”.studies.

    Phi #131,

    Actually I agree with you there. I have yet to be convinced that there is a divergence “problem”. I implied as such in #117. Indeed, have you read Esper et al., 2010: http://www.geo.uni-mainz.de/Dateien/Esper_2010_GCB.pdf ? It looks to me like much of “the decline” in the tree rings they were trying to “hide” also occurred in the weather records. If so, that actually gives me more confidence in the use of (well-chosen) tree rings as temperature proxies! :)

    The point I was getting at was that if we treat the instrumental records as “training data” for our model, then once the model is constructed, the model has to stand on its own two feet from then on.

    If it “can’t detect” some particular temperature trend at some period, it doesn’t matter how convinced you are that the trend did happen, you just have to say:
    “well, IF that trend is real, my model is unable to detect it, so I can’t use the model to tell if it’s unprecedented or not”. :(

  132. phi said

    Blog Lurker,

    There, I fully agree with you. I did not know Esper 2010, I will read it carefully. It appears to be a further confirmation to the hypothesis of a divergence having the source in thermometers. Some other arguments are TLT, alpine glaciers (Huss et al. 2009), Snow (Marty 2008), homogenization (Hansen et al. 2001). Regarding the length of the period affected by the divergence, anything interesting there http://noconsensus.wordpress.com/2011/11/27/provenance-of-the-decline-a-forensic-analysis/.

  133. AMac said

    Phi #133,

    I’m not well-enough educated on this point to agree or disagree.

    I have followed the story closely enough to develop a certain distrust — skepticism, you might say — of the ways the divergence problem has been handled by the paleoclimate community

    It’s not that hard for a scientifically-literate layperson to chart the correct approach, since it builds off common sense. As Carrick said (# 130), “the right way to do science is to consider first the best methodology, implement it as well and impartially as you can, and only then “lift the lid” and see what its implications are.”

    Advocacy, groupthink, and the “sunk costs” of prior high-prestige guesswork seem to make it very hard for the leading lights to engage in course correction.

    New developments in the story cause — and should cause — further losses of confidence in the Mainstream consensus. This is a tragedy — there are serious issues (e.g. sensitivity to CO2 doubling) that call out for strong and trustworthy science.

  134. phi said

    AMac,
    I quite agree with you, I just think we have enough evidence to say that the specific issue of the divergence comes from the thermometers. The reconstruction of thousand years temperatures raises many other problems in addition to the poor calibration.

  135. Blog Lurker said

    Phi,

    I’d only started reading that post before I got sucked into this one instead! ;) Will have another look…

    I do think that the various age standardisation approaches (RCS in Briffa’s case) that have been applied to chronologies are relevant. Are you familiar with the age detrending problem?

    I know it is a hot topic in dendroclimatological circles, so I’m not saying it’s not being discussed. But, considering the substantial differences between different standardisations & that much of the justification for one method over another is that “it reduces the divergence problem” (which as we’re saying may not be a “problem”), I haven’t been satisfied…

    P.S. I wouldn’t completely agree with your reply #135. I’d rather say that there is currently insufficient “evidence to say that the specific issue of the divergence” is a tree ring problem (or at least exclusively a tree ring problem). There’s too much hand-waving to go the other extreme just yet.

  136. phi said

    Blog Lurker,

    “I do think that the various age standardisation approaches (RCS in Briffa’s case) that have been applied to chronologies are relevant. Are you familiar with the age detrending problem?”

    I am not an expert, I stated in comment # 51 1) nearly all what I knew about it.

    “I’d rather say that there is currently insufficient “evidence to say that the specific issue of the divergence” is a tree ring problem (or at least exclusively a tree ring problem).”

    On the same thread 1), links given in # 12, might show some of my reasons to say that the divergence is an issue related to thermometer.

    1) http://noconsensus.wordpress.com/2011/11/27/provenance-of-the-decline-a-forensic-analysis/

  137. Jeff Id said

    Phi,

    On the scientific side of blogging. Something which is unfortunately gone for a bit. There are some very interesting emails about RCS standardization and the right way to do it. It seems that there is some judgement based selection going on inside the construction of series as well that I was unaware of. SteveM was criticized about it in one of the most recent emails regarding Yamal RCS for simply running all the series through the process at the same time.

  138. Blog Lurker said

    Phi,

    I’d have to see a bit more of how you calculated those graphs before I could comment (preferably in English – I only studied French for a few years, when I was a teenager! :( ). I will say that, from my own analysis of 20th century temperatures, my own hunch is that things were closer to your yellow line than to the CRUTEM3 red line. But, I’m not ready to present my analysis just yet. Maybe in the New Year.

    However, if you’re going to argue that tree rings are better than e.g., CRUTEM, you will have to resolve a few issues. The first priority is to look more carefully at the justifications for a given standardisation technique. R. S. Bradley (of MBH98/99 fame) wrote a chapter on dendroclimatology in his 1999 textbook, which gives you a primer (as well as some poorly reasoned mumbo-jumbo on PCA). I think there’s a copy on Keith Briffa’s webpage. Briffa & a few others are pushing RCS these days. That Esper 2010 article I linked earlier argues against it.

    I think you’ll need to understand the reasoning behind RCS before you can dismiss it. But, I have problems with the statistical properties of the few RCS chronologies I’ve looked at. (and I think Yamal’s ridiculous uptick is mostly an artefact of that). I think the problem is that many climate scientists develop a “homogenisation” technique from a theoretical basis… Test it on a few toy samples… Then assume it works on everything. :(

    Another priority you’ll need to look at is what I call the “convergence problem”. ;)
    If you look at e.g., CRUTEM3, you’ll find temperatures from the start (1850) are decreasing for a few years. But, ALL the multiproxy estimates are increasing “from the Little Ice Age”. You might say, “sure, but that’s only a few years” – it’s just noise. But, if you look at the few long instrumental records/composites (mostly European), it seems to be systemic. Exactly how cold & long the LIA was, used to be a tricky question until Jones & Bradley, 1993 and then MBH98/99 came along. Have a look at Ogilvie & Jonsson, 2001: http://www.springerlink.com/content/n5002234m466v577/ (Clim. Change seems to be open access right now!) for a history – it also gives one of the long composites in Figure 4.

    In my opinion the question was never satisfactorily answered.

    A few of those looking at the problem, e.g., Frank et al., 2007: http://www.geo.uni-mainz.de/Dateien/Frank_2007_QSR.pdf have decided that the early temperatures were biased warm, due to them having a different exposure. Essentially, they argue like Anthony Watts that poor exposure biases the data. But, because they’re trying to INCREASE the global warming trend, unlike Watts, that’s apparently ok! ;)

    You’ll want to be careful trying to question that though, as you’ll annoy both the believers who reckon there’s been continuous global warming since the industrial revolution and the sceptics who claim that the recent global warming is just “a natural recovery from the Little Ice Age” or else, is somehow related to sunspot numbers.

  139. phi said

    Blog Lurker,

    Thank you for the links, I will study all this carefully. There are many complications with global NH, so I try above all to understand what is happening at the regional level using data that I think are the most reliable. Raw data of Schweingruber for individual series seems to me exemplary for this. In addition, we know that the raw MXD of twentieth century can only possibly be biased upward by the principal bias known (age).

    The issue of “convergence” in the eighteenth and nineteenth is actually curious, especially, as for divergence, it also affects the glaciers (Vincent 2005). As this “convergence” affects particularly summer temperatures, we could indeed see a problem of thermometers insolation.

    In any case I look forward to discover your own analysis.

  140. Blog Lurker said

    Phi,

    No problem. There may well be a problem with exposure for the early records, e.g., in England, in the early 1700s, readings were supposed to be taken in a north-facing, draughty room(!), but the same applies to modern measurements, e.g., Anthony Watts’ “Surfacestations” findings. I suspect it is not that trivial a problem to properly account for, and I don’t know that it will explain all of the large differences between current proxy & instrumental LIAs. That’s why I mention it. Certainly, I haven’t found many obvious step changes that would account for a shift to e.g., Stevenson screens yet, so it’s not a simple problem.

    I also think it’s unscientific to try and only find out what is “wrong” with the data which doesn’t fit your theory & assume the rest is fine. So many climate scientists seem to forget that you should always leave your theories to the side when you’re analysing your data!!! :( That’s why I’m a little concerned with the eagerness with which some folk (Phil Jones, David Parker, etc) are honing in on that one possible bias… What are the chances we’ll ever hear a Menne & Williams, 2010-style announcement saying that the early exposure “doesn’t matter”, like we got for Anthony Watts’ findings, do you think? ;)

    Anyway, good luck!

  141. [...] we know from work by Jeff Condon at Air Vent that Briffa, Mann, et al cherry picked tree rings for proxies since there is no real clear [...]

  142. Rotten to the core said

    Let me illustrate the power of their technology:::
    The gods create the perception of global warming by beeming heat into (cold out) of the polar icepacks, ultimately causing rising sea levels. As they can listen to your thoughts and affect your behavior so can they the animal kingdom, which is behind the changing migrating patterns of hundreds of millions of birds all at once, changing growth patterns for foliage as well as the changing weathern patterns we all experience.
    Similarly, the gods can do this with food. They can beem sugar out of fruit, flavor out of shrimp.
    I suspect like the biotechnology issue they use genetic engineering to accomplish the goal of bland produce to eliminate their culpability, but they are far too much of control freak rapist fuck degenerate shit to paint with such a broad brush. Rather it occurrs on an individual-by-individual basis. This way they can maintain conditioning/reinforcement and denial at the same dinner table.
    Realize they can also affect taste, so their options are open. As with the retard, military draft and other examples from earlier, expect it boils down to an issue of culpability::If the gods don’t accept blame they won’t “make it up to us” and the decay we experience accelerates.

    The gods are in possession of absolute power and take total control over proceedings on Planet Earth using the tools at their disposal to manage and achieve the desired perception and results in society. One of these tools is clone “clone host” fake people.
    As people age the gods bestow wisdom according to their level of favor. All people, from the gutter-dwelling homeless to the chairman of the board, would achieve this wisdom at some level, and some would change their path in life. Because of the importance of the upper eschelons in Earth’s decay the gods used this tool of clone hosts to ensure nothing changes as would when their “reals” learned::A constant turnover of eager 20 year-old preditors ensures a fresh new supply of young people eager to “earn”. Ironic it is the youth who ensures Planet Earth’s stagnation, whereas society says something quite opposite.
    Only through a historical event like this Situation is large-scale change possible. It’s not only an issue of the 20 year-olds learning they made a mistake with their choice but also of the gods still being willing to allow this macro change.

    The gods used Christainity as temptation to repel people away from themselves. The pentagram is charecterized by xtianity as a symbol of Satan but ironically the reality is the opposite:::The god’s holy symbol. Similarly, the penticle, the reverse pentagram, is the real symbol of hatred of the gods. If those foolish enough to behave in this manner hate the gods then they should have the real thing, which will cost them in the end.
    Don’t forget::::It is not a house of Jesus.
    Christianity is evil. It is responsible for slavery of Africans. It is responsible for this wicked reject dumping ground known as the United States which was used to destroy the Old World around the globe.
    There is a major difference between how Europe and the rest of the world were inflicted with xtianity:::Push vs. pull strategy. As a result, expect the “1000 years with Jesus on Earth” may be reserved for the Europeans and few others who were forced into this evil religion:::The god’s management of culpability defines the level of compensation everyone receives.
    The god’s primary goal with this Situation was their minimization of culpability arising from inflicting us with the 20th century and/or liberal counter-culture. Everything I have taught is true. Now that this Situation is complete the disfavored have been taught. The gods are no longer/minimally responsible from this point forward, pitiful “reach around” compensation for ruining your Planet Earth. Their empty promise to me “We’ll make it up to him.” has been met with similar inadequate compensation in your case, and the gods will find a way to wash their hands of this obligation to me as well.
    If they were honest how little they ultimately intended to grant us our sacrifice would have ended long ago, but they used this lie “We’ll make it up to them.” to further our misery, with absolution of obligation on the agenda for the future.
    My experience is obscene. I paid everything. But at least the gods got what they wanted. Imagine how fucked up their behavior if they didn’t.
    Rotten to the core.

    The gods offered Clues about my importance, who I am. They occurr on a weekly, even a DAILY basis. The tip of the iceberg is listed below::
    Air France’s Concorde
    Christa McAuliffe, Concord, NH
    Carnaval’s Costa Concordia
    Concord:::In the “eye of The Beast”
    Downey Savings
    1998:: “He gets 4 years.”, “(His chance is OVER!!)”:::2.1.03 (SS Columbia) & 11.26.03 (Aérospatiale-BAC Concorde).
    My miracle of Ocean Beach, witnessed by MILLIONS on the West Coast
    Mt. Zion:::Slowly being eaten away until one day paradise is gone forever
    Carry That Weight
    Unit 731::TSUSHOGO
    Zastava Koral

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