Thursday, August 27, 2015

Mark Steyn's Expert Comes Up Short

Mark Steyn is back, looking for money to pay a lawyer. And pushing opinions instead of science.

Awhile back Steyn quoted a Jonathan Jones, Lecturer in Physics at Oxford University, about Mann's work. So I wrote to Dr. Jones asking for more details. Despite Jones' bluster, what I found wasn't very convincing.

Steyn quoted Jones:
The Hockey Stick is obviously wrong. Everybody knows it is obviously wrong. Climategate 2011 shows that even many of its most outspoken public defenders know it is obviously wrong. And yet it goes on being published and defended year after year.

Do I expect you to publicly denounce the Hockey Stick as obvious drivel? Well yes, that's what you should do. It is the job of scientists of integrity to expose pathological science... It is a litmus test of whether climate scientists are prepared to stand up against the bullying defenders of pathology in their midst.
As I showed here, the hockey stick is, in fact, an elementary result of basic scientific reasoning. So I was curious about the surety of Jones' conclusions, given that I couldn't recall any papers by him on the subject.

On August 11th, I wrote to Jones:
Why do [you] hold this view? Why is it "obviously wrong?" The hockey stick has been reproduced several times now, some using independent mathematical techniques
and I gave him links to Tingley and Huybers, Marcott et al, and PAGES 2k.

Jones replied:
The quotation Mr Steyn is using can be found in context at http://www.bishop-hill.net/blog/2011/12/2/tim-barnett-on-the-hockey-stick.html#comment16080991.

I’m afraid that I am somewhat confused by your question, as your suggested conclusion does not follow from your premises.  However I will do my best to answer.

First please note that my comments which you quote apply specifically to the Mann hockey sticks, MBH98 and MBH99.  The methods underlying these reconstructions have been comprehensively debunked, most famously by Steve McIntyre; if you are unfamiliar with the story then I suggest “The Hockey Stick Illusion” by Andrew Montford as an excellent primer.  Even if one accepts the underlying method of multiproxy reconstruction with effective selection of individual proxies by correlation (and like most people outside the small world of people doing such reconstructions I don't) the inclusion of "proxies" known not to be reliable temperature proxies (e.g. bristlecone pines and contaminated lake sediment series) and the use of inappropriate mathematical techniques (mostly famously decentred PCA in MBH98) renders the reconstructions useless.

These papers are methodologically bogus, and would remain methodologically bogus even if other papers were to reach similar conclusions.  In so far as such papers rely on the same bogus methods then their conclusions are equally invalid; conversely papers which reach similar conclusions by different means have nothing to say in support of the bogus methods of MBH.

You mention three particular reconstructions, none of which provide any support for the methods in the MBH papers.

The Marcott 2013 multi-proxy reconstruction is most famous for the dramatic uptick which occurs at the end of the reconstruction.  However it is now well known that this uptick is not robust, and is almost certainly an artefact.  It is notable that this uptick does not occur in Marcott’s thesis, and I understand that the authors no longer defend this portion of the reconstruction.  Once this uptick is removed there is nothing much to see unless you are advocating splicing temperature data onto proxy data.

The Pages2K 2013 reconstruction suffers from many of the same problems as the MBH reconstructions, with many datasets in common, including contaminated lake sediments and bristlecone tree ring series known to be unsuitable.  Famously some of the series are used "upside down": this is a common error in papers which use selection by correlation, and a clear indication of why the method shouldn't be used.  The paper adds little or nothing to the debate on MBH.

The Tingley and Huybers story is a long and complex one, and I am not sure quite which paper you are referring to, but many of their papers have used notorious “proxies” such as Mann’s PC1, the Yamal lone tree, and the most famous of the upside down contaminated lake sediment series, Tiljander's data as used by Mann.  The mathematical techniques used are not as different as you suggest, and any similarities in outcome largely reflect the inclusion of the same inappropriate proxies.  Once again it adds little or nothing to the debate.

I apologise that this reply is not particularly detailed, but I am currently very busy with the fallout from admissions and examining.  If you want to read more about the deficiencies of the reconstructions above I suggest you take a look at McIntyre’s site, climateaudit.org, although you may find that the posts there swiftly become rather technical unless you have a strong mathematical background.
This is clearly just a lot of hand-waving -- not sure if Steyn and his readers are familar with that scientific slang -- so I followed up to Jones:
Of course I know about McIntyre & McKitrick, but I haven't seen many experts take it very seriously, especially after Wahl and Amman (2007):

"Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence, Eugene R. Wahl and Caspar M. Ammann, Climatic Change, November 2007, Volume 85, Issue 1-2, pp 33-69
http://link.springer.com/article/10.1007%2Fs10584-006-9105-7

My point about the other reconstructions -- Marcott et al, PAGES 2k, and Tingley and Huybers -- is that, if independent analyses find essentially the same result at MBH, using different mathematical techniques, how can Mann et al be so badly wrong?
Jones' reply:
I'm afraid that I don't share your take on Wahl and Amman. In fact this paper largely establishes the correctness of the McIntyre and McKitrick criticisms. In particular I draw your attention to table 1S on page 63.

If you would like to read more about this it is explored in some detail in Montford's book.  Or, if you don't want to read the whole book, see "Caspar and the Jesus Paper" which you can find at http://bishophill.squarespace.com/blog/2008/8/11/caspar-and-the-jesus-paper.html

Your final question was answered in detail in my previous reply, so I am confused as to why you are asking it again.
I found it odd that a scientist would cite a blog. The difference between peer reviewed papers published in major journals and blog posts is -- or should be -- very obvious. (Yes, that holds for this blog as much as any other. Blog posts aren't science.) They simply aren't in the same league, and it is very rare, if ever, you will ever see a scientist cite a blog post.

So I asked Jones about his own work on the hockey stick.
Your criticisms of all these papers -- Marcott et al, PAGES 2k, Tingley & Huybers -- strike me as shallow. They are hand-waving.

Where are the peer reviewed papers showing them wrong?

Have you published any papers showing them wrong?

I'm a science journalist. I'm well aware that blogs can, and do, say anything, with few, if any, consequences for being wrong. So I prefer to work from the peer reviewed literature.
I never heard back from Dr. Jones.

Maybe asking about his own publications was a touchy subject for him. But blog-level thinking isn't good enough for professional scientists -- I can get that anywhere. The point of being a professional is to offer professional critiques. Jones did not do that. I don't see much, if any, merit in his replies.

I'm sure Steyn's readers will be impressed by whatever he writes and whomever he quotes. And Judith Curry will repeat them without question.

But as Jonathon Jones showed, at least, his criticism quoted by Steyn wasn't scientific, and wasn't impressive or convincing.

Steyn's readers got all hot and bothered by this post, but completely ignored the posts that showed how the hockey stick is an unsurprising consequence of basic physics.

I suspect most of them don't understand basic physics. Science simply isn't their interest. Instead, they are thrilled by rhetorical fluorishes and debate scoring, whether it's been the Second Iraq War or writing that sates their Islamophobia.

But as Neil deGrasse Tyson said, “The good thing about science is that it's true whether or not you believe in it.”

123 comments:

Ben said...

"how the hockey stick is an unsurprising consequence of basic physics"
Really? What have measuring widths of tree rings and statistical evaluations to do with physics? The very simple assumption that tree rings indicate past temperatures, and only temperatures, has never been physically or let alone biologically proved.

Jack Savage said...

"I never heard back from Dr. Jones."

You may think this was because of your penetrating questions, insight and analysis.

However, I suspect there may be another reason.

Really, Mr. Appell, you are not doing yourself any favours here!

Elby the Beserk said...

Thanks, best laugh I've had in a long time. Fantastic .... hand-waving. Bless you.

Mistress.Magoo said...

I have a pack of drinking straws.
Would yo like one to hold?

Les Johnson said...

Mann's hockey stick was actually demolished by the NAS.


Mann says he is vindicated by Bloomfield and the NAS. The congressional record shows this to be false. To make matters worse, when the Oxburgh Panel looked at the climategate emails, Prof Hand was quite critical of the Hockeystick. Hand was President of the Royal Statistical Society.

http://www.telegraph.co.uk/earth/environment/climatechange/7589897/Hockey-stick-graph-was-exaggerated.html

Mann tried to get Bloomfield to have Hand back down. What happened is not quite what Mann wanted. From Bloomfield to Hand:

"A quick rereading of the report didn’t reveal any place where I, ^ or any other member of the committee reached any conclusion with which you would differ. If you’re aware of any, I’d be glad of a reminder!"

Mann thought he was getting an apology:

"By the way, Mann said Hand got his criticism of the stats all wrong and would be issuing a clarification/ apology. True?"

Not true. This from Fox to Hand. And no apology was issued.

"Subject: aghhhhhhhhhhhhhhhhhh
Hi Folks – assuming (praying) this is not true? If it – or any version of it – is true – can we chat about it and how the SMC might help? If it’s rubbish someone might want to suggest to Michael Mann that he decease from suggesting it to BBC reporters."


http://climateaudit.org/2014/02/17/mann-and-the-oxburgh-panel/

CHAIRMAN BARTON. I understand that. It looks like my time
is expired, so I want to ask one more question. Dr. North, do you
dispute the conclusions or the methodology of Dr. Wegman's report?
DR. NORTH. No, we don't. We don't disagree with their
criticism. In fact, pretty much the same thing is said in our
report. But again, just because the claims are made, doesn't
mean they are false.
CHAIRMAN BARTON. I understand that you can have the right
conclusion and that it not be--
DR. NORTH. It happens all the time in science.
CHAIRMAN BARTON. Yes, and not be substantiated by what you
purport to be the facts but have we established--we know that
Dr. Wegman has said that Dr. Mann's methodology is incorrect. Do
you agree with that? I mean, it doesn't mean Dr. Mann's
conclusions are wrong, but we can stipulate now that we have--and if
you want to ask your statistician expert from North Carolina that
Dr. Mann's methodology cannot be documented and cannot be verified
by independent review.
DR. NORTH. Do you mind if he speaks?
CHAIRMAN BARTON. Yes, if he would like to come to the
microphone.
MR. BLOOMFIELD. Thank you. Yes, Peter Bloomfield. Our
committee reviewed the methodology used by Dr. Mann and his coworkers
and we felt that some of the choices they made were inappropriate.
We had much the same misgivings about his work that was documented
at much greater length by Dr. Wegman.


http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=109_house_hearings&docid=f:31362.wais

madadadam said...

The only "hand waiving" I see going on, is from yourself.

Victor Venema said...

I found it odd that a scientist would cite a blog.

He might be a scientist, but works in a fully different field. He can embarrass himself as much as he likes to when it comes to paleo-climatology without any professional repercussions. Without incentives to hold a defensible position, you should expect more outliers.

Reliable science is a community effort. The pubic is well advised to focus on the long-term understanding of the scientific community rather than single papers and persons, especially outliers. Journalists like such outliers, a surprise is newsworthy, people are more interesting than abstract thoughts, but they are not a reliable sources of information.

(An expert who can judge the arguments naturally does not have to do this.)

EliRabett said...

Gerry North nailed it (and Jones) North chaired the NRC panel which evaluated the Mann Bradley and Hughes papers

"While we did find some of the methods used in Michael E. Mann's original papers to be less cautious than some of our members might have used, we have not found any evidence that his results were incorrect or even out of line with other works published since his original papers."

EliRabett said...


FWIW, there is an interview with North at the Chronicle where he concludes

"There is a long history of making an inference from data using pretty crude methods and coming up with the right answer. Most of the great discoveries have been made this way. The Mann et al., results were not 'wrong' and the science was not 'bad'. They simply made choices in their analysis which were not precisely the ones we (in hindsight) might have made. It turns out that their choices led them to essentially the right answer (at least as compared with later studies which used perhaps better choices)."

tonyhellerakastevengoddardisnotasociopath said...

Trying to debate science in the arena of public opinion where polemicist Mark Steyn dwells is a fruitless exercise, as I so brilliantly point out here:

Connecting the Dots Between Michael Mann’s Alleged Misogyny and Mark Steyn’s Rumored Homosexuality

Unknown said...

I'm reading this on a BLOG.

Russell Seitz said...

Steyn's grasp of climate science rivals that of his yack radio mentor, Rush Limbaugh.

His performance at the last of the Heartland Institute's ersatx 'International Climate Conferences' failed to make even the blog science grade:

http://vvattsupwiththat.blogspot.com/2015/06/mark-steyn-and-grapes-of-wrath.html"

mikep said...

Professor Jonathan Jones gives you some concise arguments why MBH is suspect: use of suspect proxies, non-centred PCA, correlation screening. You then reply by an argument from authority, quoting one very poor peer reviewed article. And you accuse Professor Jones of handwaving. Unbelievable.

angech said...

His view seems complete, concise and clear.

David Appell said...

Ben wrote:
"What have measuring widths of tree rings and statistical evaluations to do with physics? The very simple assumption that tree rings indicate past temperatures, and only temperatures, has never been physically or let alone biologically proved."

Ben: My proof of the hockey stick has nothing to do with tree rings or any other proxy. That's precisely the proof's strength.

http://davidappell.blogspot.com/2015/08/more-about-generating-hockey-sticks.html

Tim said...

Blogger David Appell said...
Ben wrote:
"What have measuring widths of tree rings and statistical evaluations to do with physics? The very simple assumption that tree rings indicate past temperatures, and only temperatures, has never been physically or let alone biologically proved."

Ben: My proof of the hockey stick has nothing to do with tree rings or any other proxy. That's precisely the proof's strength.

http://davidappell.blogspot.com/2015/08/more-about-generating-hockey-sticks.html


The Hüsler and Sornette paper discusses the level of CO2 emissions relative to population growth: essentially humans create CO2, and thus more humans create more CO2 - the resultant graphs of both population growth and CO2 are "Hockey Sticks." This is not terribly controversial.

Your post claims that there is a direct correlation to temperature (with no mitigating natural effects) - if not with the tree ring data, then how?

David Appell said...

Tim wrote:
"Your post claims that there is a direct correlation to temperature (with no mitigating natural effects) - if not with the tree ring data, then how?"

Because CO2 is a heat-trapping gas. So the temperature rises.

Mailman said...

And yet is remained static for nearly 2 decades in spite of co2 levels rising.

Mailman

andthentheresphysics said...

I'm still struggling to understand how this

And yet it goes on being published and defended year after year.

is consistent with this

First please note that my comments which you quote apply specifically to the Mann hockey sticks, MBH98 and MBH99.

Gordon Fulks said...
This comment has been removed by a blog administrator.
Australian Actuary said...

David Appell, you really should take a step back. Accept the obvious: Mann's work was not scientific. You are defending the indefensible. A science journalist should show respect for the scientific method. So many scientists are explaining why Mann's work was bogus and yet you refuse to hear them.

dave said...

Steyn's "expert" looks rather like the Jonathan Jones who is not a climate scientist, but who took on board blogger Steve McIntyre's complaints about not getting climate data from the Climatic Research Unit. On 24 July 2009 Jonathan Jones made a Freedom of Information Request for data which the unit had been allowed to use by various meteorological organisations, with no permission to pass the data on to other parties. When this FOIA request was decided in favour of Jones in July 2011, he graciously said his aim was "to help restore climate science to something more closely resembling scientific norms." Rather worrying that he's lecturing Oxford students on norms when his own approach seems to be credulous belief in anything bloggers tell him, without bothering to check.

An example is his suggestion of “The Hockey Stick Illusion” by non-scientist blogger Andrew Montford as "an excellent primer", when he should know that it's obvious drivel. This is clearly shown by its claim that the IPCC 1990 first assessment report "suggested that past temperatures had been warmer than today in a long period lasting from the eleventh to the fifteenth centuries." Why couldn't Jones even try reading the report to check?

Andrew Jones said...

Hi David,

I apologise if I appear to be something of a stuck record on this but it has genuinely bothered me that you have stated an inability (due to financial pressures) to purchase Steyn's new book,

"A Disgrace to the Profession": The World's Scientists on Michael E Mann, his Hockey Stick and their Damage to Science.

Vol 1.

I wanted you to know that I have accordingly just purchased a new copy for you and I have instructed Mr Steyn to personally autograph and inscribe the book for you.

The least you can do is read it in the hope that you find a fatal flaw contained within its pages. You might even actually destroy Steyns case? Does that make sense?

All I need is to know where to forward it too.

Please do read it David.

Andrew Jones said...

Eek!

Typo.....forward it "TO"?...

Otter said...

Andrew Jones~ Please forward it to the Wizard of Oz. You know, the Guy Behind The Curtain.

Andrew Jones said...

Thank you for the suggestion Mr Otter,

I just need an address and I'll get onto it.

If I get Mr Steyn to just write "There's no place like home" on the jiffy bag would that do?

Colonel Robert Neville said...
This comment has been removed by a blog administrator.
Tim said...

David Appell said...
Tim wrote:
"Your post claims that there is a direct correlation to temperature (with no mitigating natural effects) - if not with the tree ring data, then how?"

Because CO2 is a heat-trapping gas. So the temperature rises.
11:01 AM


Seriously? Not even Mann is claiming such a gross over-simplification - and you are accusing others of "hand-waving"?

I think you need to acknowledge that your argument presumes "all other things being equal" ... but of course they aren't.

andthentheresphysics said...

I think you need to acknowledge that your argument presumes "all other things being equal" ... but of course they aren't.
Not really. It's based on the idea that the largest change in forcing in the last 1000 years has been the change in anthropogenic forcing between the mid-1800s and now. Given that this is indeed probably the largest change in forcing over the last 1000 years, anything other than something that looks like a hockey stick would be very surprising.

Jack Savage said...

"Not really. It's based on the idea that the largest change in forcing in the last 1000 years has been the change in anthropogenic forcing between the mid-1800s and now. Given that this is indeed probably the largest change in forcing over the last 1000 years, anything other than something that looks like a hockey stick would be very surprising."

On reading that, the years slipped away and a vision of a well-groomed politician on a cherry picker in front of a large graph filled my inner eye. We appear to have gone full circle. Suddenly everything is gloriously simple again.

I did rather anticipate this turn of events in the climate change world. Sooner or later the hiatus in surface temps is likely to come to an end (especially considering the way they are constantly adjusted) enabling people like ATTP and David Appell to slip back into the original oh-so-simple CO2-is-the-control-knob thesis like a pair of old slippers. So much easier than all that stuff about ocean heat and the dozens of other explanations...so much easier to sell to the plebs.

andthentheresphysics said...

Jack,
I don't recall mentioning CO2. Can you point out where I did so?

dave said...

Ben and Jack seem very simple. Take Ben's opening misdirection:
The very simple assumption that tree rings indicate past temperatures, and only temperatures, has never been physically or let alone biologically proved.
The only ones making that assumption are deniers like Ben: tree ring density and width are known to respond to various factors, including precipitation, in dendroclimatology trees are assessed as to which factor is significant, and the proxy used accordingly. As for proof, that's for maths or whisky, not biology: Ben's claim sounds like a creationist argument.

Similarly, Jack is still clinging to the nonexistent "hiatus" and implying a giant conspiracy of all the climate scientists.

But both leap to the defence of Jonathan Jones who isn't a climate scientist, and whose only claim to fame in the field amounts to getting raw temperature data from Trinidad and Tobago released against their express wishes, for deniers to fail to use.

Jack Savage said...

I do apologise. Mr Appell mentioned the demon molecule and I made the error of assuming that, as you have leapt to his defence, your mention of "forcing" related to the increase in CO2 in the atmosphere.

If, as it seems it does not from your umbrage taking, what is the largest change in forcing to which you are referring?

Jack Savage said...

Regarding the "hiatus"...I am from over the pond in the UK and even our Met Office seems to have recognised the existence of the pause ( even though it of course claims its existance does nothing to put in doubt the theory of man made CO2 driven global warming) so I am wondering whether to believe our Met Office or to go with the gentleman called "dave" who says it is non-existant.

Perhaps "dave" could contact them, tell them of their error, and let me know the outcome.

They can be found here.

http://www.metoffice.gov.uk/research/news/2015/variations-rate-global-warming

andthentheresphysics said...

Jack,
The largest change in forcing that we have experience in the last 1000 years is probably the change in anthropogenic forcing that we've been experiencing since about the mid-1800s. Given this, it would be extremely surprising if a reasonable reconstruction of our millenial temperature history did not have a shape like that of a hockey stick,

Tim said...

andthentheresphysics said...
Jack,
I don't recall mentioning CO2. Can you point out where I did so?
3:56 AM


The author's claim (which I refuted as overly-simplistic) is that Mann is vindicated because more humans = more CO2 = more heat. Is your claim Mann is vindicated because more people = [black box] = more heat?

andthentheresphysics said...

Is your claim Mann is vindicated because more people = [black box] = more heat?
No, my claim is that - given our current understanding of changes of forcing over the last 1000 years - any millenial temperature reconstruction that did not look something like a hockey stick would be very surprising.

Tim said...

andthentheresphysics said...

No, my claim is that - given our current understanding of changes of forcing over the last 1000 years - any millenial temperature reconstruction that did not look something like a hockey stick would be very surprising.
7:13 AM


Appell claims his model supports the Hockey Stick without relying on proxy data ... how do you reconstruct the last 1000 years of temperature data without it? Or for that matter, come to "our current understanding of changes of forcing"?

dave said...

Hi Jack, you seem to be misreading the link to the Met Office's news report from February: they discuss what was then thought to be a recent temporary slow-down in the rate of global surface warming, while noting that others called this a "pause" or "hiatus".

Rather out of date, yesterday's Indy notes that recent data make a nonsense out of claims of a "pause" and reports Phil Jones of CRU saying 2015 is "going to be so far ahead of the other record year [2014] that it’s going to be beyond the error range". Look forward to the Met Office's update. Or perhaps you prefer the Daily Mail's reporting?

andthentheresphysics said...

Or for that matter, come to "our current understanding of changes of forcing"?
Well, we have proxies that tell us something of how Solar TSI has changed over that period. There are studies that give us information about changes in volcanic activity. There are estimates for changes in anthropogenic forcing. All this points to the change in anthropogenic forcing that has occured since the mid-1800s being larger than any other change in forcing over the last 1000 years. Hence any millenial temperature reconstruction that didn't have a hockey-stick-like shape would be rather surprising.

David Appell said...

Colonel Robert Neville: Your comment was removed. Name-calling and insults aren't allowed on this blog.

David Appell said...

Gordon Fulks: The discussion here is about science..... Insults go elsewhere.

David Appell said...

Tim wrote:
"Appell claims his model supports the Hockey Stick without relying on proxy data..."

No, I did not. I wrote, "Thus, it would be surprising if any of the paleoclimate studies gave anything other than a hockey stick...it seems to me a hockey stick is the best, first guess."

http://davidappell.blogspot.com/2015/08/more-about-generating-hockey-sticks.html

and

"Of course, you still have to collect the proxy data and calibrate it and work through all the complicated mathematics to find what the actual temperature variation over the last X millennia is....The hockey stick isn't a surprising result."

http://davidappell.blogspot.com/2015/08/the-thing-is-hockey-stick-isnt.html

Jonas N said...

Thank you for posting this David, and also commenting.

Thank you also ATTP, JoshH for your supportive comments.

It makes a great read!

Jack Savage said...

`@ATTP

"The largest change in forcing that we have experience in the last 1000 years is probably the change in anthropogenic forcing that we've been experiencing since about the mid-1800s."

Which is what? For the second time of asking.

andthentheresphysics said...

Jack,
If you search for "AR5 Radiative forcing diagram" it should return a RealClimate post that shows the AR5 diagram with all the different anthropogenic forcings and how they've change over different time intervals. RealClimate appears to be down at the moment, or else I would have linked to their post. It's not that important for this illustration, though. The largest change in radiative forcing in the last 1000 years is probably the change in anthropogenic forcing since the mid-1800s. Hence any millenial temperature reconstruction that did not have a hockey-stick-like shape would be very surprising.

Tim said...

No, I did not. I wrote, "Thus, it would be surprising if any of the paleoclimate studies gave anything other than a hockey stick...it seems to me a hockey stick is the best, first guess."

To paraphrase: "any other result would be surprising" - you did not write this to support Mann's hockey stick (the underlying subject of discussion)?

FWIW, it's a terrible first guess as we don't fully understand the role CO2 plays in climate - let alone any of the other variables (many of which have not been investigated to anywhere near the depth that CO2 has) - it's more of a shot in the dark. The Romans had a "best, first guess" as to why the sun rose in the morning and the seasons changed ... how did that turn out?

"Of course, you still have to collect the proxy data and calibrate it and work through all the complicated mathematics to find what the actual temperature variation over the last X millennia is....The hockey stick isn't a surprising result."

And equally, anything other than a hockey stick wouldn't be surprising result!

Hockey stick results (in any system) need to be closely investigated as can often be the result of bad methodology or bad data (or both), rather than a "catastrophic" change ... I've seen much evidence of both errors in CAGW theory, and the (more telling) reaction to same is to obfuscate, accuse, and hide behind legal "authority" (Mann's lawsuits, Suzuki's pronouncements that skeptics should be imprisoned, etc.). That's where the argument goes from, "hey, that's interesting and maybe alarming - let's have a look at it" to "you guys are full of it!"

Tim said...

OpenID andthentheresphysics said...
Well, we have proxies that tell us something of how Solar TSI has changed over that period. There are studies that give us information about changes in volcanic activity. There are estimates for changes in anthropogenic forcing. All this points to the change in anthropogenic forcing that has occured since the mid-1800s being larger than any other change in forcing over the last 1000 years. Hence any millenial temperature reconstruction that didn't have a hockey-stick-like shape would be rather surprising.

7:50 AM


There are plenty of estimates and guesses using various proxies leading to varying guesses of expected change - the link to anthropogenic forcing and supposed "tipping points" is only a guess (and based on CO2 levels and temperatures of the last ~20 years a rather bad one at that).

David Appell said...

Tim: The role of CO2 is understood very well, and especially its forcing equation. Arrhenius knew in 1896 that CO2's forcing was logarithmic.

That's all my argument depends on. It's a very simple argument that easily shows that any result *besides* a hockey stick would be the real surprise.

David Appell said...

Tim: Nothing about the last 20 years says anything surprising about CO2's radiative forcing.

Undertanding the last 20 years has mainly been about getting a better understanding of

1) natural variability
2) getting the temperature data right

Ed Snack said...

David, you have cited Wahl & Amman. Their results as published show that Mann's 1998 & 199 results have no statistical validity before around 1700. Once you take that on board the conclusion is "if we select for proxy records that go up in the 20th century then these go up in the 20th century. Furthermore, if we weight these proxies by how much they go up in the 20th century then they go up a lot". Not a ground breaking result, is it.

What's more, there's a peer reviewed (yes, the "gold standard") paper from 1993 that comes to the conclusion that the large increase in ring widths for the Bristlecone Pines is due to CO2 enrichment. Therefore there use as a temperature proxy using the PC1 component by Mann is invalid, the PC1 must be, according to peer reviewed science, CO2 enrichment. Mann doesn't show the cause, he simply assumes it, that is utterly non-scientific. Omitting the BC data also radically changes the results.

Face it, Mann et al 1998 & 1999 are simply politically convenient puff pieces but are not scientific by any any definition. Those who claim otherwise are either deluded or profiting from the deceit.

David Appell said...

Ed: The conclusions of Wahl and Ammann 2007 is:

"Our examination does suggest that a slight modification to the original Mann et al. reconstruction is justifiable for the first half of the 15th century (∼+0.05–0.10◦), **which leaves entirely unaltered the primary conclusion of Mann et al.**

Emphasis mine.

David Appell said...

Ed: A hockey stick still results if the bristlecone proxies are left out:

http://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/

http://www.sciencemag.org/content/325/5945/1236.abstract

Tim said...

Blogger David Appell said...
Tim: The role of CO2 is understood very well, and especially its forcing equation. Arrhenius knew in 1896 that CO2's forcing was logarithmic.

That's all my argument depends on. It's a very simple argument that easily shows that any result *besides* a hockey stick would be the real surprise.


4:06 PM


Multivariate statistics exists so that we can try understand how variables interact in complex systems, without tainting our observations with what we already believe to be true. Impartially speaking, results you find surprising (or not) have absolutely no relevance to the observation.

Blogger David Appell said...
Tim: Nothing about the last 20 years says anything surprising about CO2's radiative forcing.


Really? Your argument is that linear increases in CO2 (which most definitely has happened) create logarithmic increases to temperature (which definitely has not happened): you aren't surprised that the result is exactly what you aren't predicting?

Undertanding the last 20 years has mainly been about getting a better understanding of

1) natural variability


Well that's precisely the point - in complex systems changes in input variables (i.e., CO2) sometimes result in UNEXPECTED changes to output variables (i.e., temperature). "Natural variability" is really just obsfucation (or hand-waving, if you prefer): in more straightforward terms, one would say "a bunch of other variables that we don't really understand and haven't really gotten around to checking out." Clearly, in the case of climate, there is much more going on (otherwise all of the models would have accounted-for the possibility of a two-decade "pause") ...

2) getting the temperature data right

Which is even more nuts: we are supposed put our faith in (rather sparse and spurious) proxy data for historic information, when we can't even agree on current observations? So much for Settled Science.




mikep said...

If you leave out bristlecone pines and Gaspe you don't get a hockeystick from MBH methods. SO while it's strictly true that you get a hockeystick if you leave out bristlecones, it's only there because of the equally suspect Gaspe proxies which now do all the heavy lifting.

David Appell said...

mikep: Why leave out the Gaspe series?

You can reconstruct past temperatures with no tree ring data at all, and still get a hockey stick:

http://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/

Not at all surprising.

David Appell said...

Tim wrote:
""Natural variability" is really just obsfucation (or hand-waving, if you prefer): in more straightforward terms, one would say "a bunch of other variables that we don't really understand and haven't really gotten around to checking out.""

Ridiculous. There has been a great deal studied and written about the factors that cause natural variability, especially in the last 10 years vis-a-via the Pause.

"Which is even more nuts: we are supposed put our faith in (rather sparse and spurious) proxy data for historic information, when we can't even agree on current observations?"

Also ridiculous. I see little disagreement among scientists (and it's their agreement that matters, not your's or mine or some denier blog's) about the need for data homogenization or how it's done, and the recent corrections made by Karl et al. In fact, the quickness with which GISS adopted the new Karl et al SST data suggests they reviewed with it and agree with it.

David Appell said...

Tim wrote:
"Multivariate statistics exists so that we can try understand how variables interact in complex systems, without tainting our observations with what we already believe to be true. Impartially speaking, results you find surprising (or not) have absolutely no relevance to the observation."

Of course they do. You don't start a long calculation before you do simple, heuristic calculations first.

Given just the aGHG data and simple physics (radiative forcing equations), they show there is good reason to expect a hockey stick.

It's not surprising that's what the actual, detailed, statistical reconstructions find.

Tim said...

David Appell said...

Ridiculous. There has been a great deal studied and written about the factors that cause natural variability, especially in the last 10 years vis-a-via the Pause.
, etc.

So after 8 or so years of real world observation invalidating the models, it only then became important to study natural variability: and we still don't know it's limits or really understand it's drivers. In order for the CAGW theories to be correct, the range of natural variability would have to be shifted to higher values, with catastrophic consequences - we further would have to recognize (per "tipping point" claims) that the climate system was no longer stable (within the limits of natural variability) but has become an UNstable system characterized by runaway warming.

OR maybe there is not a Pause at all, and it's just our data collection and/or analysis that's the problem.

OR both.

But definitely NOT anything else. At least not anything that would confirm that observed data invalidated the models.

This is not science - this is grasping at straws! What ever happened to "Settled Science?"

Setting aside tipping point B.S. for the moment, as long as nobody can really define the limits of natural variability, let alone what drives it (with any kind of certainty), blaming it for the Pause is impossible to disprove (or prove). Thus, the claim is an even more specious that the underlying CAGW theory, existing only to buy time with the gullible.

Of course the idea that CAGW models may not be accurate is not a possibility, right?

pauld said...

So in your view the hockey stick graphs are pretty much superfolous?

David Appell said...

"So in your view the hockey stick graphs are pretty much superfolous?"

No, and I never wrote that. I wrote that a result other than a hockey stick would be surprising.

dave said...

Tim really is grasping at straws, indeed throwing up lots of strawmen to cling to his denial of reality. So now that it's over, the short term "Pause" was supposed to be only eight years long? Variability and cycles were known about long before these "Pause" claims started, which is why the classical WMO period for defining climate is 30 years.
Model projections depend on unpredictable variables, which is why they're not predictions, though it's been shown that projections which happened to make the right assumption about unpredictable cycles such as ENSO turned out to closely match the measured outcome.

All of which is a strawman when it comes to the topic of this post: perhaps Tim, like Steyn, doesn't realise that the MBH reconstructions aren't climate models, and weren't studies of the modern temperature record, though they did relate the record which others had produced to the MBH proxy reconstructions of climate in earlier centuries.

The topic is whether the non-expert opinion of Jonathon Jones helps Steyn's claims: since that opinion is backed up only by reference to non-expert bloggers, it's unlikely to help Steyn much.

andthentheresphysics said...

What I guess some people aren't recognising in what David is trying to say is that there is more than one way to develop understanding of our millenial temperature history. On multi-decade timescales, the dominant driver of climate change (as measured by average global surface temperatures) is probably changes in external forcings. There are a number of lines of evidence suggesting that the largest change in external forcing in the last 1000 years has been the change in anthropogenic forcing starting in about the mid-1800s. Therefore we would expect the largest change in average global surface temperature in the last 1000 years to have occured since about the mid-1800s. Therefore if there are other independent ways to estimate global surface temperatures for the last 1000 years, it would be very surprising if these methods produced results that did not have an underlying hockey-stick-like shape.

If we're going to try develop understanding of a system we're going to be more confident if multi lines of evidence give the same basic picture than if they were inconsistent.

Andrew Jones said...

I am happy to purchase a kindle edition for you if you'd prefer David?

David Appell said...

Andrew: Again, thanks but no thanks.

Latimer Alder said...

Jonathan's criticism of Mann Hockey Stick is perfectly easy to understand.

Stripped of the academic niceties - Mann cooked the books.

And foolish folks uncritically went along with it because it seemed to give the result they expected and/or wanted.

Further Reading: The Emperor's New Clothes. HK Andersen.

David Appell said...

Latimer: At least 38 other hockey sticks have been found:

http://davidappell.blogspot.com/2015/08/36-hockey-sticks-and-counting.html

Do you prefer to pretend they don't exist?

Latimer Alder said...

@david

Jonathan makes his remarks and their context perfectly and unambiguously clear.

'Note that my comments which you quote apply specifically to the Mann hockey sticks, MBH98 and MBH99'

Whether or not other folks have come to similar conclusions by other means is completely irrelevant to the question of the legitimacy of Mann's methods and conclusions.

And Jonathan says as much - albeit wrapped up in acadamicese

'These papers are methodologically bogus, and would remain methodologically bogus even if other papers were to reach similar conclusions. In so far as such papers rely on the same bogus methods then their conclusions are equally invalid; conversely papers which reach similar conclusions by different means have nothing to say in support of the bogus methods of MBH.'

I'm pretending nothing. Your citation of other hockey sticks is immaterial to the discussion.

David Appell said...

Latimer:

"Methodologically bogus" how?

Stop waving your hands like Jones and start presenting science. Such as:

"Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence." Wahl and Ammann, Climate Change, November 2007, Volume 85, Issue 1, pp 33-69.
http://link.springer.com/article/10.1007%2Fs10584-006-9105-7

dave said...

Latimer, your argument is completely bogus. Jonathon based his remarks on fraudulent comments by bloggers, not on scientific literature, and you seem to have nothing to add but unsupported abuse.

Do you base your own comments on the same low quality sources that Jonathon quoted?

Latimer Alder said...

@david

I seriously wonder if you read Jonathan's remarks at all before opining that they were 'handwaving'.

He explains 'methodologically bogus' in the paragraph immediately preceding. Thus:

'Even if one accepts the underlying method of multiproxy reconstruction with effective selection of individual proxies by correlation (and like most people outside the small world of people doing such reconstructions I don't) the inclusion of "proxies" known not to be reliable temperature proxies (e.g. bristlecone pines and contaminated lake sediment series) and the use of inappropriate mathematical techniques (mostly famously decentred PCA in MBH98) renders the reconstructions useless'

He also provides excellent references where these points are further discussed. If you have not yet read them, I commend them to your attention.

Latimer Alder said...

@dave

I refer you to the remarks I addressed to David A some moments ago.

David Appell said...

Latimer: Quoting someone who presented no science (let alone his own work on the topic) does not mean you have presented any science.

That should be clear enough.

So, again, "methodologically bogus" how, exactly?

Tim said...

dave said...
Tim really is grasping at straws, indeed throwing up lots of strawmen to cling to his denial of reality. So now that it's over, the short term "Pause" was supposed to be only eight years long?


Er, what?

Variability and cycles were known about long before these "Pause" claims started, which is why the classical WMO period for defining climate is 30 years.
Model projections depend on unpredictable variables, which is why they're not predictions, though it's been shown that projections which happened to make the right assumption about unpredictable cycles such as ENSO turned out to closely match the measured outcome.

...

The topic is whether the non-expert opinion of Jonathon Jones helps Steyn's claims: since that opinion is backed up only by reference to non-expert bloggers, it's unlikely to help Steyn much.
12:49 AM


Yes, and in doing so he referred back to another post about the generation of hockey sticks - which he seemed to suggest supported the findings of Mann, et.al. ... he's since clarified to confirm that his point was that the similarity of the shapes of the curves is "unsurprising" - rhetoric to convince the lay-person, not science or mathematics.

As with any described relationship, MBH (and any other reconstruction for that matter) would be validated (or invalidated) by observed results - comparing the relationship suggested by the model (using proxy data) with actual 'direct' data. When the observed results don't fit the hypothesized relationship (that is, the model), the model is wrong. "Natural variation" is little more than another way of saying that the models are incorrect: they did not adequately explain the relationship (between CO2 and temperature in the context of the global climate). CAGW may be a real thing, but on the other hand it may not - the models we have do not confirm the claim.

climateaudit.org said...

David,
in our original commentary on Mann et al, we did not take a position on the medieval-modern relationship, only that Mann's claim to have resolved this with statistical confidence were invalid both due to poor proxies and poor methodology. In particular, we rejected his claims to statistical "skill" and "robustness" to presence/absence of dendroclimatic proxies, in particular, Graybill stripbark bristlecone chronologies.

Your named examples are singularly inapt as supposed confirmation.

None of the proxies in the Marcott reconstruction individually have noticeable 20th century changes. The "blade" in the Marcott reconstruction is an erroneous artifact of his method. Marcott and coauthors ought to have published a corrigendum.

The Tingley and Huybers reconstruction effectively splices instrumental and proxy data (much like Mann et al 2008). The largest proxy component of their network is Briffa MXD data, which notoriously has a decline. They also use the contaminated Tiljander sediments introduced by Mann et al 2008 (also upside down). You may recall Mann's denial that paleoclimate scientists spliced instrumental and proxy data, but this is not true for Tingley and Huybers (or for Mann et al 2008) or amusingly for smoothed curves in Mann et al 1998-99 itself.

The PAGES2K Arctic network also has important defects, some of which have already been conceded by the authors. They admitted (McKay and Kaufman, 2014) that they used the Hvitarvatn series upside down, among several other errors. After correcting this error, the 20th century is no longer the warmest century in their Arctic reconstruction. A revised series is archived in connection with McKay and Kaufman 2014. I asked Nature to request that PAGES2K publish a corrigendum, but they refused.

In commentary, you refer to such criticisms as "arm waving", but the defects are real enough. You complain that these errors are not documented in peer reviewed literature. In my opinion, it is the responsibility of authors to issue corrigenda for such errors and your complaint lies with the authors and journals, who have evaded those responsibilities.

You also say: "You can reconstruct past temperatures with no tree ring data at all, and still get a hockey stick: http://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/"

Please note that the no-dendro reconstruction of Mann et al 2008 relied on the contaminated Tiljander sediments. Mann issued a sort-of concession of the problem in the SI to a different paper (Mann et al 2009) but failed to publish a corrigendum in the original article, thereby fostering incorrect understanding of the situation by you and many others.

Please note that many, if not most, proxies do not have a HS shape. You have to be alert for cherrypicking and ex post correlation in many multiproxy studyes and I urge you to take care in drawing conclusions.

Steve McIntyre

Gras Albert said...

ATTP
It's based on the idea that the largest change in forcing in the last 1000 years has been the change in anthropogenic forcing between the mid-1800s and now. Given that this is indeed probably the largest change in forcing over the last 1000 years, anything other than something that looks like a hockey stick would be very surprising.

Interesting

CDIAC's Global Carbon Emissions data [1] stretches back to 1751, accumulated anthropogenic carbon emissions in the period 1997-2014 totaled 138,427 million metric tonnes [2] or some 34% of all carbon ever emitted by human activity.

Given that the same period saw the slowdown (hiatus, pause, etc) in global temperature increase despite the addition of more than one third of all historic anthropogenic forcing, would you consider the absence of a hockey stick blade in the observed temperature record significant?

[1] http://cdiac.ornl.gov/ftp/ndp030/global.1751_2011.ems

[2] CDIAC data ceases in 2011, I have used the 2011 data for the period 2012-14 which, since global emmissions continue to rise [3], is an underestimate.

[3] http://edgar.jrc.ec.europa.eu/news_docs/jrc-2014-trends-in-global-co2-emissions-2014-report-93171.pdf

David Appell said...

Gras: The period since 1750 has seen many "pauses." Also, many "surges."

It's natural variability.

So what is your point? No one expects temperature to increase monotonically year-after-year....

David Appell said...

Steve McIntyre:

When you publish a real paper in a real journal on Marcott et al or Tingley and Huybers or PAGES 2k, let me know.

Your blog posts aren't science -- they are self-published meanderings played to the choir, with little-to-no review of anything by any experts. Just blog posts. And blog posts aren't science.

-- David

Gras Albert said...

David
Gras: The period since 1750 has seen many "pauses." Also, many "surges."

It's natural variability.

So what is your point? No one expects temperature to increase monotonically year-after-year....

The satellite record shows no significant global mean temperature increase over an 18 year period during which 34% of all anthropogenic carbon emissions were added to the atmosphere...

Are you really suggesting this lack of correlation is due to natural variation while the previous 18 year period during which global mean temperature rose at 0.2ºC per decade is due to anthropogenic forcing?

andthentheresphysics said...

Steve McIntrye,

None of the proxies in the Marcott reconstruction individually have noticeable 20th century changes. The "blade" in the Marcott reconstruction is an erroneous artifact of his method. Marcott and coauthors ought to have published a corrigendum.

I don't think this is true. The blade in Marcott et al. is not robust (as they say in the paper itself). They do not have the resolution to robustly determine the 20th century warming. This is not the same as it being at artefact. Maybe you should read the discussion here a bit more carefully. You might also consider publishing a corrigendum yourself?

climateaudit.org said...

ATTP, I am aware of the discussion at Real Climate, which, was, at least in considerable degree, an (inadequate) response to my criticisms, which I also communicated directly to Marcott.

You challenged my observation that "none of the proxies in the Marcott reconstruction individually have noticeable 20th century changes." I've looked very closely at the data and this is 100% correct. It is a valid question as to how Marcott got his big blade when none of the individual proxies went up materially.

You say that lacking "resolution to robustly determine the 20th century warming" ... is not the is not "the same as it being at artefact." I think that we may be in agreement on this point. While the blade is not "robust", it is also an "artefact".

You say that I should examine the real climate article by Marcott. I am very familiar with this article, which, in considerable part, was a response to my prior criticisms, though, following real climate practice, they didn't cite or link that commentary.

You say that I should publish a "corrigendum". Unfortunately, only the authors can publish a "corrigendum". Obviously I could submit a comment on the article, but, in my opinion, the primary obligation for correcting an error rests with the authors; otherwise disputes linger on pointlessly. I think that the authors should have taken their medicine and published a correction, but they didn't.

As to David Appell's dismissal of my criticism of Marcott et al and Tingley and Huybers as nothing more than "self-published meanderings" and that blog posts are not "science": I think that there is a considerable amount of weakly reviewed and poorly conducted research even in prominent academic journals. I am familiar with both the proxies and the methodologies and I try to provide informed commentary. If you think that my criticisms of these two articles are incorrect, please tell me and I'd be happy to re-examine the issues.



climateaudit.org said...

One of the sentences above is unclear on reading. "I've looked very closely at the data and this is 100% correct." By this, I re-iterate that "none of the proxies in the Marcott reconstruction individually have noticeable 20th century changes" and absolutely do not agree with ATTP's criticism on this point.

andthentheresphysics said...

Steve,
I am aware of the discussion at Real Climate, which, was, at least in considerable degree, an (inadequate) response to my criticisms, which I also communicated directly to Marcott.

So what? That you don't like it doesn't make it inadequate.

You say that I should publish a "corrigendum". Unfortunately, only the authors can publish a "corrigendum".
I was being sarcastic. Insisting that people publish some kind of corrigendum is - in my opinion - a rather juvenile tactic, and I was simply responding in kind.

You challenged my observation that "none of the proxies in the Marcott reconstruction individually have noticeable 20th century changes."
No, I didn't.

By this, I re-iterate that "none of the proxies in the Marcott reconstruction individually have noticeable 20th century changes" and absolutely do not agree with ATTP's criticism on this point.
I don't care what you agree with. Publish your criticism, rather than doing blog science. Then I might care. Also, as you probably realise, but might not admit, the interesting thing about Marcott et al. is that it illustrates that the Holocene has been broadly stable, with a general cooling trend for the last few thousand years. The recent warming is known from the instrumental temperature record and Marcott et al. indicates that it is probably unprecedented (both in magnitude and rate) across the Holocene. That you would focus on the largely irrelevant uptick in their reconstruction, and ignore the actual significance of their work, would seem to indicate that your goal is to cast doubt, rather than actually engage with the topic.

climateaudit.org said...

David Appell cited Marcott as support for the Hockey Stick i.e. the blade. I pointed out that the Marcott blade was an artefact and did not provide the claimed support. Neither you nor Appell have provided a reasoned defence of Appell's original claim. Note that the recent OCEAN2K study - also consistently mainly of alkenone and Mg/Ca ocean cores - doesn't show a stick.

If the Marcott blade was, as you say irrelevant, then the authors should have issued a correction removing the artefact so that people like Appell would not be misled.

In addition, the idea that there has been "a general cooling trend" for the last few thousand years is hardly original with Marcott, but conventional in paleoclimate.


andthentheresphysics said...

David Appell cited Marcott as support for the Hockey Stick i.e. the blade.
I don't know the reason David cited Marcott et al. but I see no reason to think that he meant the blade. The instrumental temperature record tells us what the blade should look like. The hockey stick analogy comes from the period prior to the instrumental record being reasonably flat (relative to 20th century warming, at least). In that sense Marcott et al. confirms the basic hockey stick. It's not the 20th century part of their reconstruction that does this. Arguing over their uptick just comes across as an attempt to sow doubt.

andthentheresphysics said...

In addition, the idea that there has been "a general cooling trend" for the last few thousand years is hardly original with Marcott, but conventional in paleoclimate.
I didn't say it was. That this is not a surprise is not an argument against a piece of research.

David Appell said...

Gras: I'm simply saying that AGW and natural variability coexist. Trends (especially short one like 18 years) are mixtures of both.

Here's what Carl Mears of RSS wrote last year:

"Does this slow-down in the warming mean that the idea of anthropogenic global warming is no longer valid? The short answer is ‘no’. The denialists like to assume that the cause for the model/observation discrepancy is some kind of problem with the fundamental model physics, and they pooh-pooh any other sort of explanation. This leads them to conclude, very likely erroneously, that the long-term sensitivity of the climate is much less than is currently thought."

http://www.remss.com/blog/recent-slowing-rise-global-temperatures

Tim Hill said...

Here's what Carl Mears of RSS wrote last year:

"Does this slow-down in the warming mean that the idea of anthropogenic global warming is no longer valid? The short answer is ‘no’. The denialists like to assume that the cause for the model/observation discrepancy is some kind of problem with the fundamental model physics, and they pooh-pooh any other sort of explanation. This leads them to conclude, very likely erroneously, that the long-term sensitivity of the climate is much less than is currently thought."


Actually no, questions about the validity of the models stem from the underlying methodologies in creating them - the discrepancy between model & observation merely underscores the concerns.

And they accuse "deniers" of strawman arguments ...

David Appell said...

What model discrepencies?

Tim Hill said...

The ones admitted-to by Carl Mears in the article you quoted ... I see in the article that his "view is that the subduction of heat into the ocean is very likely a significant part of the explanation ..."

Interesting, that so many seem to deny that the fault with the models themselves is a possibility ...

David Appell said...

Who denies that faults with models is a possibility?

andthentheresphysics said...

If you read Section of this Hansen paper, it makes a similar argument. It is possible that some of the discrepancy is because we're not quite getting that rate at which energy is deing deposited into the deep ocean right in the models. Something to bear in mind, though, is that this would influence the transient response (i.e., if the rate at which energy goes into the deep ocean is faster than the models currently suggest, then the surface will warm more slowly), but won't influence the equilibrium response (since that is dominated by feedbacks in the atmosphere - water vapour, lapse rate, clouds).

Tim said...

I was being facetious (which is why it's in italics) - for suggesting that it a possibility, I've been called a 'denier' (including in the comments of this article) ... you yourself (also in these comments) made reference to "denier's blogs."

Not sure what it is we are supposedly denying - I think it's pretty widely agreed that the climate is subject to constant change, and that mankind, as part of the system, has had some kind of non-zero impact. Disagreement seems to be the degree to which mankind's contribution is measurable and/or "catastrophic": the point is that the models that supposedly prove this seem questionable, and require modification to support observed data (and/or that the data observation itself is wrong - we're not sure which).

For suggesting that these models are incomplete or inaccurate (much of which is tacitly admitted by alternating explanations of natural variability, heat 'hiding' in the oceans and/or elsewhere, etc.), we get labelled with a name otherwise normally reserved for those that claim the Holocaust never took place!

If the true believers are so sure of their claim, why don't they just respond directly to the criticisms (and quash them!), rather than obsfucating about the quality of the source and name-calling (Godwin much)??

David Appell said...

"I think it's pretty widely agreed that the climate is subject to constant change"

No it isn't. The Holocene has been notable for its remarkable climate stability. It's what allowed civilization to grow and flourish. And not it's ended.

"Disagreement seems to be the degree to which mankind's contribution is measurable and/or "catastrophic": the point is that the models that supposedly prove this seem questionable, and require modification to support observed data (and/or that the data observation itself is wrong - we're not sure which)."

Models don't have a "catastrophic threshold or setting. I don't even know what that word means in the context of climate change.

"For suggesting that these models are incomplete or inaccurate (much of which is tacitly admitted by alternating explanations of natural variability, heat 'hiding' in the oceans and/or elsewhere, etc.), we get labelled with a name otherwise normally reserved for those that claim the Holocaust never took place!"

The word "denier" meant something before the Holocaust. It still carries that same meaning -- "one who denies."

"If the true believers are so sure of their claim, why don't they just respond directly to the criticisms (and quash them!), rather than obsfucating about the quality of the source and name-calling (Godwin much)??"

Boo hoo. Like all the name calling is from one side. Buck up.

climateaudit.org said...

Ken Rice says:
"I don't know the reason David cited Marcott et al. but I see no reason to think that he meant the blade. The instrumental temperature record tells us what the blade should look like. The hockey stick analogy comes from the period prior to the instrumental record being reasonably flat (relative to 20th century warming, at least). In that sense Marcott et al. confirms the basic hockey stick. It's not the 20th century part of their reconstruction that does this. Arguing over their uptick just comes across as an attempt to sow doubt."

David cited Marcott et al as support for the validity of the Hockey Stick as a temperature reconstruction. A Hockey Stick shape necessarily has both a shaft and a blade. Since the supposed "blade" of the Marcott reconstruction is an artefact, it doesnt support David's claim. That was my point.

The Ocean2K reconstruction, for example, doesn't have a blade. Even David hasn't claimed that it supported Mann's reconstruction, though it appears that you are taking this position.

You believe that the Marcott reconstruction is interesting in other respects, but that's not what David claimed. To borrow your expression, it's a "look, squirrel".

You propose that one use the temperature record to document the blade, but unless one can show that the proxies used in the reconstruction pick up the 20th century warming, you are in effect merely splicing modern temperature data to past proxy data, a practice of which Mann said in 2004:

"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."

David Appell said...

climateaudit wrote:
"As to David Appell's dismissal of my criticism of Marcott et al and Tingley and Huybers as nothing more than "self-published meanderings" and that blog posts are not "science": I think that there is a considerable amount of weakly reviewed and poorly conducted research even in prominent academic journals. I am familiar with both the proxies and the methodologies and I try to provide informed commentary. If you think that my criticisms of these two articles are incorrect, please tell me and I'd be happy to re-examine the issues."

As I said before, if you think they are incorrect, send a letter to the journal they were published in, or a rebuttal paper. I see such letters and rebuttals all the time.

I really don't care how "familiar" you are with the proxies and methodologies. So are the authors of all these papers.

I'm a science writer and journalist. I'm not a scientist, or a paleoclimate expert, or an expert on the hockey stick. For me, peer review is a basic filter your work must pass through. You can write on your blog all day long, but it will rarely if ever be reviewed by experts. It attracts the choir who is already prejudiced against the hockey stick, and their review, if you can call it that, means next to nothing.

Why don't you writeup your claims and send them to journals?

David Appell said...

climateaudit.org wrote:
"If the Marcott blade was, as you say irrelevant, then the authors should have issued a correction removing the artefact so that people like Appell would not be misled."

I don't feel mislead. Their hockey stick "blade" is from about 250 BP.

Why *wouldn't* they use 20th century thermometers for their graph? We know those temperatures, and there's no need for proxies for them.

David Appell said...

climateaudit wrote:
"David cited Marcott et al as support for the validity of the Hockey Stick as a temperature reconstruction. A Hockey Stick shape necessarily has both a shaft and a blade. Since the supposed "blade" of the Marcott reconstruction is an artefact, it doesnt support David's claim. That was my point."

I disagree with your point -- Marcott et al shows a clear upturned blade after about 200 yrs BP.

My little argument about superexponential growth says nothing about the long shaft of the hockey stick. It says that anthropogenic GHG forcings turned sharply upward with the Industrial Revolution, and that implies -- with little-to-no competing anthropogenic or natural forcings for competition -- there should be an upturn -- a blade -- in the reconstructions.

Tim said...

You just proved my point ... and failed to answer the actual question: what is it that I am (supposed to be) denying?

David Appell said...

Tim: I have no idea who you are or what you're written elsewhere. Why are others calling you a denier?

andthentheresphysics said...

Ken Rice says:
Why would you do this Steve? Annoyed with me?

David cited Marcott et al as support for the validity of the Hockey Stick as a temperature reconstruction. A Hockey Stick shape necessarily has both a shaft and a blade. Since the supposed "blade" of the Marcott reconstruction is an artefact, it doesnt support David's claim. That was my point.
Yes, I know the point you're making and I'm telling you it is silly. We don't need the blade to be there, since the instrumental temperature record tells us what it should be. That the Marcott et al. blade is not robust does not mean that there isn't a blade in reality. The shaft alone can tell us if the actual temperature has a hockey stick-like shape or not. This is not complicated!

The Ocean2K reconstruction, for example, doesn't have a blade. Even David hasn't claimed that it supported Mann's reconstruction, though it appears that you are taking this position.
As far as I'm aware, it finsishes in 1900 and the paper has "pre-industrial" in the title. So why would we expect it to have a blade?

You propose that one use the temperature record to document the blade, but unless one can show that the proxies used in the reconstruction pick up the 20th century warming, you are in effect merely splicing modern temperature data to past proxy data, a practice of which Mann said in 2004:
Sorry, unless I'm misunderstanding you, this seems particularly silly. We have the instrumental temperature record which tells us the 20th century warming. If we have another dataset that gives us pre-industrial warming, then together they give us the combined temperature record. It's all measuring the same thing in the same system.

I've no idea where your Mann quote came from, but since he combined instrumental data and reconstructed data in his papers prior to 2004, I find it really hard to believe that he's arguing against that. I think anyone who suggested that we don't know the full temperature record because we have two datasets and we aren't allowed to combine them, would be laughed at.

andthentheresphysics said...

Steve,
Hmm, your quote of Mike Mann's might be regarded as somewhat misleading. The full quote here says:

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. Most proxy reconstructions end somewhere around 1980, for the reasons discussed above. Often, as in the comparisons we show on this site, the instrumental record (which extends to present) is shown along with the reconstructions, and clearly distinguished from them (e.g. highlighted in red as here).

He's distinguishing between actually grafting the instrumental data onto the proxy data (which is not what I've said or suggested) and showing the instrumental data alongside the proxy data. Now, given that we know that the Marcott et al. blade is not robust, clearly the instrumental data will not compare well with the Marcott et al. blade. That, however, does not mean that there is not a blade. It simply means that the Marcott et al. reconstruction does not robustly represent the blade. If we think their reconstruction is robust prior to 1900, then clearly by looking at their reconstruction together with the instrumental temperatures (without doing any grafting) we can see that Marcott et al. is consistent with the millenial temperature having a hockey-stick-like shape.

dave said...

So Steve McIntyre of climateaudit produced a cherry-pick that would put a creationist to shame? I'm shocked.

Well, Steve, are you intending testifying for Steyn?

If so, I look forward to seeing your explanation under oath for the 1/100 cherry-pick you used to support your MM05 claim that the MBH method "nearly always produces a hockey stick" when tested on "persistent red noise", as well as clarification as to why you used red noise that already had inflated swings.

Wonder why Steyn seems to be trying so hard to put off this case going to court...

Mailman said...

It is true, you can lead a female donkey to water but you can't make them drink (unless it's koolaid of course).

Mailman

climateaudit.org said...

David Appell says: "If so, I look forward to seeing your explanation under oath for the 1/100 cherry-pick you used to support your MM05 claim that the MBH method "nearly always produces a hockey stick" when tested on "persistent red noise", as well as clarification as to why you used red noise that already had inflated swings. "

Our observation about the bias of the MBH method was confirmed by both the NAS panel, who wrote

"McIntyre and McKitrick (2003) [sic - 2005 (GRL)] demonstrated that under some conditions, the leading principal component can exhibit a spurious trendlike appearance, which could then lead to a spurious trend in the proxy-based reconstruction. To see how this can happen, suppose that instead of proxy climate data, one simply used a random sample of autocorrelated time series that did not contain a coherent signal. If these simulated proxies are standardized as anomalies with respect to a calibration period and used to form principal components, the first component tends to exhibit a trend, even though the proxies themselves have no common trend. Essentially, the first component tends to capture those proxies that, by chance, show different values between the calibration period and the remainder of the data. If this component is used by itself or in conjunction with a small number of unaffected components to perform reconstruction, the resulting temperature reconstruction may exhibit a trend, even though the individual proxies do not."

In Mc-Mc (2005 GRL), we had summarized our red noise argument in Figure 2 as follows:
"Figure 2 shows histograms of the hockey stick index of the simulated PC1s. Without the MBH98 transformation (top panel), a 1 sigma hockey stick occurs in the PC1 only 15.3% of the time (1.5 sigma - 0.1%). Using the MBH98 transformation (bottom panel), a 1 sigma hockey stick occurs over 99% of the time, (1.5 sigma - 73%; 1.75 sigma - 21% and 2 sigma - 0.2%)."

The figure shows a histogram of ALL simulations. Your assertion that this claim is based on "cherrypicking" is as false as your original report that we had asked Mann for an excel spreadsheet. Even Wahl and Ammann didn't make this ludicrous claim.

Criticizing our emulation of the red noise properties of the NOAMER tree ring network does not refute the point. Nor is it established that the autoregression properties of the bristlecone chronologies are because of a "climate signal" as opposed to complicated noise. The NAS panel said that these chronologies ought to be "avoided" in climate reconstructions - a recommendation that ought to have put an end to the silly Mann attempt to use the bristlecone PC in climate reconstructions.

But none of this has anything to do with the spurious Marcott blade or your foolish citation of it as supposed "support" for the Mann Hockey Stick.

climateaudit.org said...

Ken says:
"As far as I'm aware, it finsishes in 1900 and the paper has "pre-industrial" in the title. So why would we expect it to have a blade?"

The data doesn't end in 1900. There are more measurements in the 20th century than in any previous century. The 20th century data doesn't have a Hockey Stick either, as you can see in their Figure S10a.

The paper is not very forthcoming (to say the least) about 20th century data. I do not see any valid reason for using "pre-industrial" either in their title or to characterize their results. If you wish to discuss this further, I suggest that you comment at Climate Audit, where I will be publishing some more details comments, as I only visited here by chance.




David Appell said...

climateaudit: I did not write what you attributed to me -- it was a different commenter who goes by the name of "Dave."

dave said...

Steve @ climateaudit, your quote from the NAS panel's Chapter 9 includes "If this component is used by itself or in conjunction with a small number of unaffected components to perform reconstruction, the resulting temperature reconstruction may exhibit a trend, even though the individual proxies do not", but doesn't go on to the concluding point in that section, "In any case, the principal components should be constructed to achieve a low-dimensional representation of the entire set of proxy variables that incorporates most of the climate information contained therein."

Your focus on PC1 misses the point that the method used correctly must include enough PCs to reproduce the original signal. As the NAS report says, "As part of their statistical methods, Mann et al. used a type of principal component analysis that tends to bias the shape of the reconstructions. A description of this effect is given in Chapter 9. In practice, this method, though not recommended, does not appear to unduly influence reconstructions of hemispheric mean temperature; reconstructions performed without using principal component analysis are qualitatively similar to the original curves presented by Mann et al." So, in practice your claim of bias is moot, and was already superseded by the use of different methods.

The 1/100 cherry-pick you used to support your MM05 claim appears in Wegman's report, "Figure 4.4: One of the most compelling illustrations that McIntyre and McKitrick
have produced". Are you denying that you produced this?

andthentheresphysics said...

Steve,

The paper is not very forthcoming (to say the least) about 20th century data.

Well, yes, the title is a "Robust global ocean cooling trend for the pre-industrial Common Era" so why should they be forthcoming about the 20th century data. I'll point out what I've pointed out before. We have the instrumental temperature for SSTs. If the 20th century portion of this data is not consistent with the instrumental SSTs, either there is a problem with their data, or they haven't yet done the appropriate analysis for the 20th century. Until a papers appears that discusses this, I'm not about to take your claims of no blade on data that is used in a paper about the pre-industrial era, all that seriously.


If you wish to discuss this further, I suggest that you comment at Climate Audit, where I will be publishing some more details comments, as I only visited here by chance.

After your recent behaviour on Twitter, I have no great interest in interacting with you any further. I have no reason to think that you're actually interested in discussing this honestly, and I regard you as a pseudo-skeptic who primarily mis-informs (intentionally or not). You don't need to like that I hold this view. That doesn't mean I shouldn't hold it.

Dumb Scientist said...

Like ATTP, I was stunned when The Auditor baselessly fantasized that scientists are "radio silent" about the Ocean2k reconstruction somehow not being a "Hockey Stick". Maybe The Auditor just innocently missed that the Ocean2k reconstruction stopped in 1900? If so, that honest mistake would explain why his imagination ran wild:

"Had the results been more HS-like, it's hard to believe that the OCEAN2K authors would not have found a way of publishing them in time for AR5. It seems to me that, since the results were "bad", the authors seem to have felt little urgency."

Bad results? The MBH99 "hockey stick" is relatively flat until 1900, which is also true for the Ocean2k reconstruction that stops in 1900.

After ATTP pointed this out, The Auditor responded with a condescending link and a modified figure "for Kenny" which still doesn't change the fact that the reconstructions (both individual and median) in the actual figure stop in 1900. Also, the last 200 year wide "step graph" is centered at 1900 and averages many robust 1800s proxy SSTs with the few proxies having sufficient resolution to record 1900s SSTs. Why would anyone expect that to be "HS-like" unless they (gasp!) compare it to modern instrumental SST records?

Again, the paper is called a "Robust global ocean cooling trend for the pre-industrial era". Right?

Does The Auditor remember complaining that supposed 'hockey sticks' had pronounced medieval periods? Does the the Ocean2k reconstruction have a pronounced medieval period?

By the way, anyone who thinks scientists had somehow underestimated the climate change between medieval times and the little ice age should read Richard Alley's response to that point and think carefully about the implications.

Dumb Scientist said...

The first sentence from the section with Figure S10a shouldn't surprise The Auditor:

"A subset (n = 21) of the Ocean2k 57 input reconstructions are dated by 210Pb dating or annual band counting, and are of sufficient resolution to potentially record 20th century SST changes..."

Since less than 40% of input reconstructions can even "potentially" record 20th century SST changes, maybe they should have extended the reconstruction and just described the 20th century part as "probably not robust"?

After all, if they'd done that there's no way contrarians would turn the words "not robust" into a series of insinuations that scientists were somehow using obscure weasel words to cover up an "embarrassing and obvious error" that's completely erroneous and misleading and shouldn't be included at all. Surely contrarians would never imply later that scientists "admitted" and "now concede" this point even though it was stated in the paper.

Instead, the Ocean2k authors showed only the "robust" reconstruction in their paper. Hence the first word in their title. Isn't that exactly what all those comments at Climate Audit were asking for? Hopefully The Auditor isn't just setting up a catch-22 where he gets to insinuate unsavory motives either way.

And once again, why should Ocean2k reconstruct 20th century SST changes? (Even ignoring the cries at Climate Audit that this would be an embarrassing and obvious error.) As ATTP and many other scientists have repeatedly noted, we already know 20th century SST changes from thermometers.

Dumb Scientist said...

Since The Auditor keeps implying the NAS agrees with him, he might try remembering that the NAS disagreed with his criticisms.

If The Auditor really wants to "provide informed commentary" then the Wegman Report's Figure 4.4 seems much more like a figure in need of auditing. Does The Auditor support the 100:1 cherry-pick that the US Congress (and posterity) have been told McIntyre and McKitrick produced?

Wegman refuses to answer simple questions about that graph, so The Auditor is our only hope to find out if Wegman was right to claim that McIntyre and McKitrick used red noise "AR(1) with parameter = 0.2". Is it possible that Wegman got this completely wrong but The Auditor has just been too busy talking about "hissy-fits", "rodents", "crack cocaine", and "heroin" to bother correcting that egregious error?

That graph helped delay urgently needed action to address climate change, and thus changed the course of human history. That 100:1 cherry-pick might be The Auditor's most important legacy.

Congratulations?

andthentheresphysics said...

>Since less than 40% of input reconstructions can even "potentially" record 20th >century SST changes, maybe they should have extended the reconstruction and just >described the 20th century part as "probably not robust"?

Yes, a very good point. In a single thread, Steve has claimed that Marcott et al. should issue a corrigendum for including a 20th century blade that is not robust, and complained that another paper did not include a 20th portion despite the Supplementary Material indicating that the number of proxies suitable for the 20th century was small and should be treated with caution.

dave said...

But.... Dumb Scientist, surely all these points will be fully explained under oath when The Auditor gives testimony to support Steyn in the upcoming trial.... after all, it's an opportunity to get the science on trial!

He'll probably also explain the remarkable similarity between the "Jan. 5, 2005 Postscript Graphic" he put online on his climate2003 website to illustrate how well his December 2004 AGU poster session had gone, and the Wegman Report's Figure 4.4 from 2006.

Because, after all, Steyn's defense is that he believed the accusations The Auditor made, and it's not much of a defense to say that he believed a semi-retired mining exploration executive who's too shy to support the accusations in court. Or do you think Steyn can just claim he was conned?

Dumb Scientist said...

Thanks, that's a remarkable similarity indeed.

andthentheresphysics said...

Wow, that's quite something. They look identical. So, we already know that the hockey sticks in the Wegman report were actually from a sample of 100 selected on the basis of having the highest HSIs, rather than being selected randomly from the MM05 sample of 10000. That already suggested that the Wegman report was not fully independent (i.e., it would seem that either they ran the same code, or they simply used MM05's data). Now we seem to have a figure posted in Jan 2005 by Steve McIntyre that is virtually identical to a figure in the Wegman report, published in 2006. Would love to hear Steve explain this one.

dave said...

While McIntyre's "Jan. 5, 2005 Postscript Graphic" set of 12 "hockey sticks" looks remarkably similar to the Wegman Report's Figure 4.4 from 2006, they're not identical as the individual "hockey sticks" differ.

Deep Climate's "Replication and due diligence, Wegman style" blog post of November 16, 2010, discussed how Wegman's illustrations were rendered directly from McIntyre and McKitrick’s archive which selected the 1% most pronounced “hockey stick” PC1s.

Further on, Deep Climate "turned to Fig 4.4, which presented 12 more simulation PC1 hockey sticks. Although this figure was not part of the original M&M article, there is a fourth figure generated in the script, featuring a 2×6 display, just like the Wegman figure. A quick perusal of the code shows that these too were read from McIntyre’s special 1% collection, although a different selection of 12 PC1s would be output each time."

So, my guess is that McIntyre used that script to produce the "2005 Postscript Graphic".

A year and a half later, the Wegman Report said "While at first the McIntyre code was specific to the file structure of his computer, with his assistance we were able to run the code on our own machines and reproduce and extend some of his results."

Looks like they used the same script selecting from the same special collection to produce their Figure 4.4, which they called "One of the most compelling illustrations that McIntyre and McKitrick have produced".

MikeR said...

'In Mc-Mc (2005 GRL), we had summarized our red noise argument in Figure 2 as follows:
"Figure 2 shows histograms of the hockey stick index of the simulated PC1s. Without the MBH98 transformation (top panel), a 1 sigma hockey stick occurs in the PC1 only 15.3% of the time (1.5 sigma - 0.1%). Using the MBH98 transformation (bottom panel), a 1 sigma hockey stick occurs over 99% of the time, (1.5 sigma - 73%; 1.75 sigma - 21% and 2 sigma - 0.2%)."

The figure shows a histogram of ALL simulations. Your assertion that this claim is based on "cherrypicking" is as false as your original report that we had asked Mann for an excel spreadsheet. Even Wahl and Ammann didn't make this ludicrous claim.'

I hope that people who care about truth in science deal with this kind of thing honestly. I see this claim that M&M "cherrypicked" made frequently. Here I see a clear response by McIntyre, that the claim is entirely false. Either answer his response, or never make this claim again. Or don't claim to be interested in truth.

MikeR said...

"Maybe The Auditor just innocently missed that the Ocean2k reconstruction stopped in 1900?" Or maybe you just innocently missed that it doesn't, that it goes right up to 2000, with more data in the last century than any of the ones before.

"Also, the last 200 year wide "step graph" is centered at 1900 and averages many robust 1800s proxy SSTs with the few proxies having sufficient resolution to record 1900s SSTs. Why would anyone expect that to be "HS-like" unless they (gasp!) compare it to modern instrumental SST records?" Reasonable question, but see http://climateaudit.org/2015/09/19/the-blade-of-ocean2k/#comment-763670, where he is addressing exactly that issue, and shows that there are no hockey stick in the data, even if you use 20-year steps instead of 200.

I'm sorry, but this kind of thing is embarrassing. McIntyre is clearly fully expert in the details of the data and the analysis, and has gone through it in considerable detail. You have not. Yet you feel free to sneer at his work. Are you trying to defend establishment climate science, or demonstrate that it needs to up its game?

If one follows these issues on climateaudit, one just gets a very strong impression that the other side doesn't need to really address his issues, because their followers generally won't know what he said anyhow.

MikeR said...

Sorry: I just meant http://climateaudit.org/2015/09/19/the-blade-of-ocean2k, not the comment on it.

Dumb Scientist said...

Apparently the best defense of the Wegman Report's figure 4.4 is to pretend everyone was talking about a different figure which isn't in that report. Disappointing but not surprising.

Apparently The Auditor's fans innocently missed that the reconstructions (both individual and median) in the actual Ocean2k figure stop in 1900. Apparently The Auditor's fans don't appreciate the irony of mocking someone for "missing" something right before quoting him not missing it.

Also, which of The Auditor's positions do "Nigel Persaud" and The Auditor's other fans support? The position where papers are misleading if they include non-robust data, or the position where papers are misleading if they don't include non-robust data?

Also, will The Auditor and his fans ever realize that modern temperatures are recorded by thermometers? Hope springs eternal...

Dumb Scientist said...

Even pointing to the Wegman Report's fig 4.2 wouldn't be a plausible defense of fig 4.4's 100:1 cherry-pick and dishonestly (or incompetently) described noise. Instead, that would just raise another question: why didn't Prof. Wegman realize The Auditor had myopically focused on PC1 rather than applying a standard selection rule like MBH98 did? And since Wegman promised the US Congress almost a decade ago that he would share his code for those figures, where is that promised code? Did Wegman lie to the US Congress?

David Appell said...

Michael Jankowski: You have no right to publish a rude comment here. If you want your comment to appear, you'll have to write decently.