Interesting news this weekend. Apparently everything we’ve done in our entire careers is a “MASSIVE lie” (sic) because all of radiative physics, climate history, the instrumental record, modeling and satellite observations turn out to be based on 12 trees in an obscure part of Siberia. Who knew?
Indeed, according to both the National Review and the Daily Telegraph (and who would not trust these sources?), even Al Gore’s use of the stair lift in An Inconvenient Truth was done to highlight cherry-picked tree rings, instead of what everyone thought was the rise in CO2 concentrations in the last 200 years.
Who should we believe? Al Gore with his “facts” and “peer reviewed science” or the practioners of “Blog Science“? Surely, the choice is clear….
More seriously, many of you will have noticed yet more blogarrhea about tree rings this week. The target de jour is a particular compilation of trees (called a chronology in dendro-climatology) that was first put together by two Russians, Hantemirov and Shiyatov, in the late 1990s (and published in 2002). This multi-millennial chronology from Yamal (in northwestern Siberia) was painstakingly collected from hundreds of sub-fossil trees buried in sediment in the river deltas. They used a subset of the 224 trees they found to be long enough and sensitive enough (based on the interannual variability) supplemented by 17 living tree cores to create a “Yamal” climate record.
A preliminary set of this data had also been used by Keith Briffa in 2000 (pdf) (processed using a different algorithm than used by H&S for consistency with two other northern high latitude series), to create another “Yamal” record that was designed to improve the representation of long-term climate variability.
Since long climate records with annual resolution are few and far between, it is unsurprising that they get used in climate reconstructions. Different reconstructions have used different methods and have made different selections of source data depending on what was being attempted. The best studies tend to test the robustness of their conclusions by dropping various subsets of data or by excluding whole classes of data (such as tree-rings) in order to see what difference they make so you won’t generally find that too much rides on any one proxy record (despite what you might read elsewhere).
****
So along comes Steve McIntyre, self-styled slayer of hockey sticks, who declares without any evidence whatsoever that Briffa didn’t just reprocess the data from the Russians, but instead supposedly picked through it to give him the signal he wanted. These allegations have been made without any evidence whatsoever.
McIntyre has based his ‘critique’ on a test conducted by randomly adding in one set of data from another location in Yamal that he found on the internet. People have written theses about how to construct tree ring chronologies in order to avoid end-member effects and preserve as much of the climate signal as possible. Curiously no-one has ever suggested simply grabbing one set of data, deleting the trees you have a political objection to and replacing them with another set that you found lying around on the web.
The statement from Keith Briffa clearly describes the background to these studies and categorically refutes McIntyre’s accusations. Does that mean that the existing Yamal chronology is sacrosanct? Not at all – all of the these proxy records are subject to revision with the addition of new (relevant) data and whether the records change significantly as a function of that isn’t going to be clear until it’s done.
What is clear however, is that there is a very predictable pattern to the reaction to these blog posts that has been discussed many times. As we said last time there was such a kerfuffle:
However, there is clearly a latent and deeply felt wish in some sectors for the whole problem of global warming to be reduced to a statistical quirk or a mistake. This led to some truly death-defying leaping to conclusions when this issue hit the blogosphere.
Plus ça change…
The timeline for these mini-blogstorms is always similar. An unverified accusation of malfeasance is made based on nothing, and it is instantly ‘telegraphed’ across the denial-o-sphere while being embellished along the way to apply to anything ‘hockey-stick’ shaped and any and all scientists, even those not even tangentially related. The usual suspects become hysterical with glee that finally the ‘hoax’ has been revealed and congratulations are handed out all round. After a while it is clear that no scientific edifice has collapsed and the search goes on for the ‘real’ problem which is no doubt just waiting to be found. Every so often the story pops up again because some columnist or blogger doesn’t want to, or care to, do their homework. Net effect on lay people? Confusion. Net effect on science? Zip.
Having said that, it does appear that McIntyre did not directly instigate any of the ludicrous extrapolations of his supposed findings highlighted above, though he clearly set the ball rolling. No doubt he has written to the National Review and the Telegraph and Anthony Watts to clarify their mistakes and we’re confident that the corrections will appear any day now…. Oh yes.
But can it be true that all Hockey Sticks are made in Siberia? A RealClimate exclusive investigation follows:
We start with the original MBH hockey stick as replicated by Wahl and Ammann:
Hmmm… neither of the Yamal chronologies anywhere in there. And what about the hockey stick that Oerlemans derived from glacier retreat since 1600?
Nope, no Yamal record in there either. How about Osborn and Briffa’s results which were robust even when you removed any three of the records?
Or there. The hockey stick from borehole temperature reconstructions perhaps?
No. How about the hockey stick of CO2 concentrations from ice cores and direct measurements?
Err… not even close. What about the the impact on the Kaufman et al 2009 Arctic reconstruction when you take out Yamal?
Oh. The hockey stick you get when you don’t use tree-rings at all (blue curve)?
No. Well what about the hockey stick blade from the instrumental record itself?
And again, no. But wait, maybe there is something (Update: Original idea by Lucia)….
Nah….
One would think that some things go without saying, but apparently people still get a key issue wrong so let us be extremely clear. Science is made up of people challenging assumptions and other peoples’ results with the overall desire of getting closer to the ‘truth’. There is nothing wrong with people putting together new chronologies of tree rings or testing the robustness of previous results to updated data or new methodologies. Or even thinking about what would happen if it was all wrong. What is objectionable is the conflation of technical criticism with unsupported, unjustified and unverified accusations of scientific misconduct. Steve McIntyre keeps insisting that he should be treated like a professional. But how professional is it to continue to slander scientists with vague insinuations and spin made-up tales of perfidy out of the whole cloth instead of submitting his work for peer-review? He continues to take absolutely no responsibility for the ridiculous fantasies and exaggerations that his supporters broadcast, apparently being happy to bask in their acclaim rather than correct any of the misrepresentations he has engendered. If he wants to make a change, he has a clear choice; to continue to play Don Quixote for the peanut gallery or to produce something constructive that is actually worthy of publication.
Peer-review is nothing sinister and not part of some global conspiracy, but instead it is the process by which people are forced to match their rhetoric to their actual results. You can’t generally get away with imprecise suggestions that something might matter for the bigger picture without actually showing that it does. It does matter whether something ‘matters’, otherwise you might as well be correcting spelling mistakes for all the impact it will have.
So go on Steve, surprise us.
Update: Briffa and colleagues have now responded with an extensive (and in our view, rather convincing) rebuttal.
Time to fight back!
Surely this community needs to sue authors like this for Libel and slander!
I’ll contribute to a legal fighting fund…
Peter Dawe
dhogaza: You’re suggesting that climate scientists aren’t aware that 1998 was an El Niño year, or 2008 La Niña?
Tilo: I’m saying that they are aware, but that it doesn’t explain the flat trend. And neither do any of the other natural elements of variation. Compensate for ENSO and you still get a near flat trend.
BPL: You’ve said this before, it’s wrong, I’ve shown you it’s wrong, and you keep repeating it anyway. For anyone who wants to see the details, here they are:
http://BartonPaulLevenson.com/Reber.html
stevenc (#442), if the study is paid for with tax **roubles**, which taxpayers should you ask?
Mark P (#404), to be an ad hominem it has to be irrelevant. Whether it’s relevant depends on what you think ClimateAudit is doing: science or Psy-Ops.
Case in point: McIntyre’s rhetorical manipulations with Gavin’s inline reply to you, posted yesterday on CA (“Gavin’s guru”).
“Intellectual property is the property of the entity paying for the study. If Monsanto pays for it then it belongs to Monsanto, if Ford pays then it is Ford’s property, if the study is paid for with tax dollars then the intellectual rights belong to the tax payers.”
Ever heard of Public/Private Initiatives?
Please tell me what happens when the taxpayers pay for 60% of a medical study and GSK pay 40%.
Please tell me what happens if a University, completely government funded, wishes to gain some more income by licensing the research they’ve done. Should this be disallowed because “you paid for it”? If so, you have to pay the universities more, because they cannot license their research.
How about US universities giving away data to European ones? How could this be stopped if all their research has to be freely available?
100% of your military budget is taxpayer funded. Are all the designs for military hardware free and open? If not, then this shows your dogma is incorrect.
“I live in a democracy, not in a technocracy. I am sorry about that, but that’s the fact jack.”
So many people here vote for sneering and condescention of you.
Because this is a democracy, you must accede to this.
325.[Response: Fine. But that doesn’t mean that every idea from outside has merit. Quoting Carl Sagan (almost) “They may have laughed at Galileo, but they also laughed at Bozo the Clown.” Ideas and contributions have to evaluated on their merits, not from where they come from. – gavin
…..
True; that’s why I read the ‘skeptics’ and have come to see that there is much there besides “DaVinci Code conspiracies’
[Response: Maybe you’d care to enlighten us? A single new idea perhaps that isn’t just the reworking well-known issue that has been worked on for years? – gavin]
….
Dr. Schmidt I sent back an answer to your (snarky) query; not sure why my response is not here. I’ll re create it
As I mentioned, I believe in Global Warming. My hometown of Scranton PA was back in the day buried underneath a glacier. That is why I see Global Warming as a good thing. That fact made me a skeptic, since it begs the question of ‘how did the glacier retreat b/4 the coal underneath it was burned. :)
[Response: Mostly due to orbital forcing changing the amount of solar radiation during the northern hemisphere summer combined with the greenhouse impacts of consequent increases in CO2 and CH4. This is pretty conventional so I’m not sure why you think it deserving of a smiley face. – gavin]
Some other ideas that I’ve picked up: A) The Hansen forecast from 1988 and reviewed in realclimate.org on May 15 called “Hansen’s 1988 Projections” were already trending towards the Scenario C (do nothing). And that was before two plus years of even colder data being recorded. The Scenario A (keep doing what we’re doing) is not in the ballpark. I would like to see your site update that chart to see how much below Scenario C we are right now.
[Response: The long term trends from 1984 in both B and C are easily within uncertainties on the observed trends, but since C makes assumptions that just didn’t happen (no further GHG growth after 2000) it is hardly relevant. B is much closer to what actually happened (though is slightly on the high side), and so is still interesting to look at. The real world has warmed at about 0.2 +/- 0.05 deg C/dec since 1984, and scenario B has a trend of 0.25 +/- 0.05 deg C/dec. That really isn’t so bad given that the naysayers at the time said it wasn’t going to warm further at all. – gavin]
B) The Martian polar caps have melted: From National Geographic “Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist SaysKate Ravilious
for National Geographic News, February 28, 2007
“Simultaneous warming on Earth and Mars suggests that our planet’s recent climate changes have a natural—and not a human-induced—cause, according to one scientist’s controversial theory. Earth is currently experiencing rapid warming, which the vast majority of climate scientists says is due to humans pumping huge amounts of greenhouse gases into the atmosphere. (Get an overview: “Global Warming Fast Facts”.) Mars, too, appears to be enjoying more mild and balmy temperatures.
[Response: This is nuts. First off, I’d like to know whether you think that the rapid thinning of the Pine Island Glacier over the last 3 years is proof of global warming on Earth? If yes, I’m astounded, but if no, then why do you think a completely analogous event is proof of global warming on Mars? Second, over the time period covered by the Martian glacier measurements, solar forcing was going down. Third, even if solar hadn’t been going down, I’m sure you’ll agree that correlation does not equal causation? Fourth, the direct impact of solar changes is small – it’s mesaured and it’s small. People have proposed mechanisms to enhance the correlation to solar cycles (via GCR impacts on clouds for instance), but perhaps you might like to think about why that wouldn’t apply on Mars. Fifth, Mars is very different planet – and it turns out that the biggest impact on temperatures is the episodic occurrences of gigantic dust storms that can cover a hemisphere, and that in fact, dust cover changes to albedo are the leading theory for why Martian climate changes on interannual timescales. Sixth…. oh I give up. – gavin]
C) The amount of grants from governments to support science which calls for more government intervention dwarfs the funding from carbon interests
[Response: Rubbish. You are simply playing with words here. If you think that understanding the Earth and all it’s subsystems is leading scientists to say that further emissions of GHGs might not be a great idea, you would be correct. But that research is completely indpendent of calls for greater governement intervention – no-one gets a grant to investigate the impact of ocean mixing processes on bugetary deadlock in the Senate. The difference between the funding for scientists to do science, and non-scientists to propagandize is pretty clear to me. Or perhaps you’d prefer that economists weren’t given grants to actual research but just to write op-eds? – gavin]
D) The term ‘denier’ is a tell that the science is far from settled. One can be a skeptic about the forecasts, esp since as noted in A) they are not very solid. However, one can not be a ‘denier’ of those forecasts, since once can not deny the future.
[Response: Terms like this are best reserved for people who repeatedly bring up long-debunked talking points not because they think they are valid, but because they think they can find some new people to fool. But this behaviour is easy to see whatever name is applied. BS by any other name would smell as bad. – gavin]
E) There does appear to be data collection and transparency issues in the AGW research area.
[Response: Give me all the data you have used to publish a paper from in the last 10 years. What? It’ll take time? Your graduate student has it? You aren’t sure where you put it? There is only 90% online – I want the last 10%! I claim conspiracy! Appears to me like there’s a transparency issue there, and you haven’t even responded. (See how easy that is?). – gavin]
BTW My PhD is in Economics, w/ a field in Econometrics. I can easily follow the data.
[Response: Try following the logic. – gavin]
re:426
“Compensate for ENSO and you still get a near flat trend.”
Jerry: So, we’re going to make the post office pay for my new stereo, now?
Kramer: It’s a write-off for them.
Jerry: How is it a write-off?
Kramer: They just write it off.
Jerry: Write it off what?
Kramer: Jerry all these big companies they write off everything.
Jerry: You don’t even know what a write-off is.
Kramer: Do you?
Jerry: No, I don’t.
Kramer: But they do – and they are the ones writing it off.
Tom: #424
Tom, since you cross posted your responses to me on CA here, I will do the same.
I have three questions for you about your work.
First, you say:
“The last chronology excluding all but the cores less than 250 years is statistically invalid. I posted it for completeness to show that the only way to break the hockeystick was to take out so many cores that the all we are seeing for most of the record is noise.”
And in an earlier posting where you first show your results you say this about the trees that are over 250 years old.
“Now there are just 32 cores left with an average age of 303 years, or just four cores at any one time.”
So if the small number of cores produce a statistically invalid result, then why doesn’t Briffa have statistically invalid results when the last years of his chronology have only 5 trees.
My next question is about tree overlap. Let’s use your sample where trees are over 200 years old, since you seem to believe that is still statistically valid. Take the 50 year time slice going from 1940 to 1990. This time slice is made up of live trees that reached their maximum age within that time slice. Another words, all the data that you are getting for that period comes from tree rings that are old tree rings greater than 150 years. Now, take a time slice from 940 to 990. Your selection method insures that all of those trees lived to be over 200, but it does not insure that they were over 150 in that time slice. Trees in that time slice could have been in their first 50 years of life – or their second – or their third. So while your method insures that all the tree rings used in the second half of the twentieth century are over 150 years old, the tree rings used will, on average, be much younger for all of the earlier periods.
My third question has to do with this. The sorting based on age is valid because, as Craig Lohele has found, Larches become more sensitive to climate as they get older. But, as we all know, elements such as water, nutrition, sunlight, etc. still play a part in tree growth as well. Briffa has stated that chronologies that do not match the surface temperature record of the region are thrown out. But that only serves to bias the chronologies to the ones that have trees that are sensitive to climate in the 20th century. Earlier trees in the same chronology receive no selection bias benefit. It seems to me that this would give you a better representation of 20th century climate, but it would make comparisons to warming in earlier periods invalid.
Walter, #430. what makes you think this story is ANYTHING to do with making a track too short to draw conclusions from, never mind done deliberately et al?
It’s about removing any large trees (that are generally the ones who lived longer) from a dataset through time.
This may be why you don’t know who dunnit.
And since the story isn’t about what you want to know, re: who dunnit, there would be no value in reading any of the story or thread to find the answer.
Cumulus: “There needs to be a permanent group out there, some third party, to which scientists can go and have the data or methods in controversial papers reviewed/audited in **private**.”
There is:
The Review Process.
Problem is, when the denialists can’t get their stuff through this rigorous test, they complain they are being silenced and avoid the process. They complain that the conspiracy includes the review process.
Solomon states: “As a statistician I believe that it is necessary to eliminate the effect of all other variables before one can be sure that there is a genuine correlation between any two.”
How do you eliminate the effect of all other variables, without finding a correlation between these variables and the data?
If you remove the correlation by any means, you’ve just had to do what the Biffa study.
IF this cannot be done for CO2 effects on tree growth, how would you do it for moisture effects on tree growth, and why is that one possible?
If it can’t be done by any means, how do you actually manage to get any answers in your work as a statistician?
My thanks to Hank Roberts 370, MarkB 388 and luminous beauty 377 for attempting to put me right. I still do not understand how anyone can deduce past climate from the growth of a living tree without first uprooting the tree or, at least doing such excavation round its roots as to do it serious damage.
In part of the fruit plantation that I helped to manage, one orange tree was at least half as big again as its neighbours. When I askes why this was it was explained to me that when the young trees were being planted the donkey that had carried many of them dropped down dead. It was buried at the spot and one of the young trees was planted on top of it. This was the tree that so outgrew its neighbours.
Would cell analysis of the core have pointed to the dead donkey? The other variables affecting growth were identical for all the trees that had been planted in that section of the plantation.
No, it belongs to whoever the contract or grant says it belongs to.
re: 459
“I still do not understand how anyone can deduce past climate from the growth of a living tree without first uprooting the tree or, at least doing such excavation round its roots as to do it serious damage.”
I don’t think Science waits on Perfection. Or the Gigantism of rhetoric. It sounds to me like Briffa (et al) were doing the trench work of Science: assembling a couple of the pieces of the mosaic. To this layman, it sounds like his critics fell upon his careful work and measured conclusions because they don’t understand careful work and measured conclusions.
“I still do not understand how anyone can deduce past climate from the growth of a living tree without first uprooting the tree or, at least doing such excavation round its roots as to do it serious damage.”
Aye, but these trees are dead.
Do you know what the story is about at all?
And you haven NEVER considered “drill a core out of a tree then pack the hole” as a method of doing tree age estimation with a live tree?
How little imagination you have.
Steve McIntyre responds, at length: http://www.climateaudit.org/?p=7278
[Response: Apparently I have a guru. Good to know. Relevant much? – gavin]
“In essence, you were supposed to ‘repeat the experiment.’ Not just ask for the scientists’ data and ‘repeat the analysis”
True Ron, but if all the data and methods are made available then other scientists may come to the conclusion that further study is not warranted, or they may find an error that was previously missed, or they may decide that the results are not conclusive and a new study is warranted. It would be rather difficult to make these decisions without all the information available I would imagine. It’s good to see the trend towards more openess.
CM, if the study is paid for with Roubles then it makes sense that those who paid for it with Roubles make that decision.
Mark, if the study has economic value then they should get a patent. If the study has military value then they should get a security classification. If the only value of the study is the furtherance of mankind’s knowledge then it is valueless unless shared.
456 Tkearney
This is shocking if true. Why would anybody with a PhD in anything post such a poorly conceived list of bullet points to a site run by professionals?
For instance:
Leaving aside the issue of trolling, there seems to be an underlying assumption that the pinnacles of earth science can be realized off hand in reasoning fit for middle school science fair projects. No. Not even that!
Truly, I’m beginning to think one of the requisites for becoming a climate scientist is the patience of a saint.
RE: Jeffrey Davis #457
Here is the plot Kramer. Gavin computed the ENSO corrected data. I just plotted it and the unajusted data. This happened near the end of last year, but I don’t expect that there are any big changes.
http://1.bp.blogspot.com/__VkzVMn3cHA/SHLOM1k5XJI/AAAAAAAAADE/u7AlyoBk0EU/s1600-h/ENSO+Adjusted+HadCrut3v+Data.bmp
“No, it belongs to whoever the contract or grant says it belongs to.”
True dhogaza, I was wondering who would point out the obvious to me. Perhaps new contracts would be the way to go if cooperation between academics is so difficult to achieve.
What makes you think cooperation between academics is so difficult? I haven’t heard academics screaming that they can’t get hands on data – the russians willingly shared their data with Briffa, for instance. What you’ve seen is McI screaming that *Briffa* should make the *Russian* data available, while a decade ago, I would guess that neither Briffa nor the Russians could possibly have imagined that Briffa would be pilloried by certain people for not having gotten permission to redistribute data …
Face it, McI is playing a political, monkeywrenching game here, whose only purpose it to confuse the public and political understanding of the science in order to delay or prevent any meaningful action to curtail CO2 emissions. He’ll do anything to achieve that goal, and you can’t blame scientists for thinking a decade ahead trying to imagine “how will McI try to screw us in the future”.
This isn’t how scientists or other technical people work. Constantly worrying about the robustness of their s***-umbrella because McI et al are out their taking dumps on their head.
for NOT thinking …
On the dead donkey question:
No, analysis of the tree rings would not have pointed to the dead donkey. Nor would it have been mistaken for a temperature effect. In fact, if all of the trees in the orchard had been cored, no temperature signal would have been observed in any of them because temperature (growing season length) is not the limiting factor in this scenario. In order to get a temperature signal from a tree core or group of cores temperature needs to be the limiting factor on growth at the site where the cores were taken.
“[Response: And the ice age provides evidence for a number of around 2x (i.e. giving a 3 deg C/2xCO2) change. Who do you trust more – a geological processes that dominated climate for 2.5 million years, or Lindzen? ;) – gavin]”
Firstly if the multiplier is 2 then it implies a sensitivity of 2C does it not? (Stefan-Boltzmann or zero-feedback sensitivity is 1C).
Secondly, the ice-age evidence is suggestive but not determinative as it does not tell us the sensitivity in today’s climate. It could well be that the sensitivity was much greater during the ice ages (note: I am not talking about Ice Albedo feedbacks which of course amplify the sensitivity relative to today. One can imagine that the water-vapor feedback was also greater in the ice age since the Earth was starting from a drier state).
Thirdly, are you arguing that we should discount all scientific argument that is not based on at least 2.5 million years of geological evidence? Had humanity followed that course we’d never have accepted Newtonian Mechanics, Special Relativity, Quantum Mechanics or in fact most of modern science.
dhogaza wrote:
If they did it would be that much attention taken away from the actual performance of science. Likewise, if climatologists or evolutionary biologists were constantly considering how their words might be twisted by denialists of one or another stripe this would greatly reduce their ability to communicate their thoughts or for that matter even think about what it is that they are studying. To the extent that they actually give consideration to such things it should only be as an afterthought — and even then I (for whatever my personal opinion might matter in this regard) would suggest that they shouldn’t devote that much time to it.
Solomon, you claimed expertise in dendrology, and I pointed out that what you’re claiming you lack is any knowledge of:
— dendrochronology.
Can you be as blank a slate as you claim?
For the next youngster who comes along and needs homework help, I’d suggest starting with
1) a dictionary, a generally reliable method for any word:
http://www.google.com/search?q=define%3Adendrochronology
and, for tips on posting style:
2) http://www.urban75.com/Mag/troll.html
See also:
I think we now have a new slang expression for the process Gavin describes as:
It is called “beating a dead donkey”.
Grudd H, (2008): Torneträsk tree-ring width and density AD 500 – 2004: A test of climatic sensitivity and a new 1500-year reconstruction of north Fennoscandian summers. Climate Dynamics, 31: 843-857. DOI:10.1007/s00382-007-0358-2.
http://www.springerlink.com/content/8j71453650116753/fulltext.pdf
#471 Rattus Norvegicus
Are you saying that the only limitation on tree-ring width in Yamal, has been temperature?
Uh, oh, denialists are now invoking the dead donkey defense. Watch out!.
Who do you trust more – a geological processes that dominated climate for 2.5 million years, or Lindzen? ;) – gavin]
With all due respect to(where have I heard that phrase before :) ) Richard Lindzen. I’m inclined to go along with the geologic record. It would be nice if skeptics varied their sources more and considered them more carefully.
“Mark, if the study has economic value then they should get a patent.”
And this still requires complete secrecy. And who are “they”? Are you saying that at this time, government funded universities AREN’T selling their work to commercial interests?
They are.
This isn’t anything to do with patents.
dhogaza, I know it was a typo, but your original version has, sadly, come true: “you can’t blame scientists for thinking a decade ahead. . .” (That is, in the chess game of denialist monkeywrenching.)
Or at least trying to. What a nightmare. . .
321:
” Quoting Carl Sagan (almost) “They may have laughed at Galileo, but they also laughed at Bozo the Clown.” Ideas and contributions have to evaluated on their merits, not from where they come from. “– Gavin
Quoting Carl Sagan more exactly: ”
“Apocalyptic predictions require, if they are to be taken seriously , higher standards of evidence than do other matters where the stakes are not as great.”
Please compare ,and if possible contrast , the respective hazards to the reputation of science of ignoring modeling uncertainty caveats, and making worst-case outliers the central focus of publicity , in the run-up to Copenhagen and the Cold War media extravaganza styled ‘nuclear winter.’
It is cautionary to recall how that one petered out because the models failed to quantitatively converge on the rhetoric – and the images – its publicists provided. Today we are witnessing an even larger investment in political PR , and the rhetorical overkill has remained constant despite all the progress in modeling. Though the list of patrons subsidizing the hype has remained the same, the process has certainly become more transparent , and one hopes sociologists will record the present comedy of manners to help avoid repetition if the failure , or worse, the selective exercise, of collective memory continues.
From what they produce for TV, some activists view climate policy as strategy for preserving civilization, and accordingly seem bent on persuading us that we face a unique moment of threat (and opportunity.)
Those among them who see science as a vehicle for politicizing revolution seem prepared to reduce popular science to the carrying on of war by other means, and the comedy of manners consists in their being shocked, deeply shocked that their actions should provoke the bumptuously anti-scientific counter-propaganda of Planet Gore and Climate Depot.
Might RC persuade Jim Hansen & Steve Schneider to engage in a dialog as to the vicious cycle of apocalyptic advertising by the environmental left and apoplectic responses by the grassroots right ?
Jerry says, “I just don’t recall any of my physics, or engineering, or chemistry, or biology professors acting that way towards the cranks that approached them, or telling us about how the great scientists would act that way.”
So, Jerry, did the cranks that approached your profs keep coming back for a decade or so with the same zombie arguments? Did that flatly accuse them of fraud? Did they have them subpoenaed to appear before committees of notjob congressmen who can’t even program a VCR, let alone understand a scientific analysis?
Reality doesn’t give a flying f**k what “the people” think. It doesn’t even care if our species survives. If we do not learn to develop a sustainable economy, we will become extinct. And that, Jerry, is the only fact that really matters.
http://www.lsu.edu/highlights/2009/10/antarctic.shtml#
Headline: Algae and Pollen Grains Provide Evidence of Remarkably Warm Period in Antarctica’s History
In the press release it states that “…proof of a sudden, remarkably warm period in Antarctica that occurred about 15.7 million years ago and lasted for a few thousand years.”
For those of you who are aware of this study, do you know what is meant by “sudden” and “remarkable”? How fast and how warm?
Thank you.
Gavin thank you for the tolerance you have demonstrated for dealing with Steve McLier! It is very much appreciated.
Johnathan Baxter says “Thirdly, are you arguing that we should discount all scientific argument that is not based on at least 2.5 million years of geological evidence? ”
Don’t be obtuse! Gavin is alluding to the fact that a sensitivity >2 has >2.5 million years of evidence in favor of it, while Lindzen’s “analysis” has… well, none. See the difference?
Tilo Reber #458:
> So if the small number of cores produce a statistically invalid result,
> then why doesn’t Briffa have statistically invalid results when the last
> years of his chronology have only 5 trees.
I know even less about tree ring proxies than Gavin, but even I understood his explanation: The validity of the chronology constructed is a very different thing from that of individual annual values.
Dhogaza, this isn’t an issue just involving tree rings nor is it an issue just involving climate research. This is an issue affecting nearly every field of research. See the opinion piece by Schofield et al in Nature 461 dated 10SEP 09.
Tony,
I am not saying that temp is the the only factor, however sites are chosen on an a priori basis where temp is likely to be the dominant factor. This is why sites at altitudinal and latitudinal tree lines are commonly chosen since growing season is the limiting factor for most species northern and upper ranges.
Mark P states (404):
“Questions to you, Gavin. Do these specific criticisms of the science in Briffa (2000) have any merit? If they are without merit, what are the specific rebuttal points which defend Briffa (2000) against them? If they do have some merit, how much do they weaken the scientific conclusions of the Briffa (2000) paper?”
A few points here in response to this, and to other various posts that I don’t have the time to cite:
1. Briffa did not collect the original data. The Russians, Hantemirov and Shiyatov did, in the 1980s and 1990s. Briffa’s modern sample was thus limited to a maximum of 17 tree series. McIntyre says straight up that he does not accuse Briffa of cherry picking the 12 of these 17 series, which is good, because it is not even clear that Briffa had all 17 to begin with.
2. The Russians state that they use 224 series in their chronology, chosen based on being the longest and most sensitive of the larger set of series, with sensitivity defined by inter-annual response to instrumental temperatures. It is thus highly likely that they chose their 17 modern cores based on these same criteria. This is perfectly valid dendroclimatic practice, and indicates that the 12 cores Briffa used in the modern chronology are sensitive to temperature.
3. Briffa’s response to Mcintyre states that these 17 trees were taken from at least 3 locations in the Yamal sampling area. Conversely Schweingruber’s 34 cores according to Briffa, came from just one location in the area. The latter would thus lack the spatial coverage of the H & S sample, even though the sample size was higher than the 12 Briffa used. Microclimatic effects could thus play a role in any of the 4 or more sampling locations.
4. The proper weighting of the modern trees, from a spatial perspective, would thus be at least 3:1 (Briffa:Schweingruber), although perhaps with some adjustment for any differences in variance between the two sets. This is why Briffa mentions in his online response that it did not appear that McIntyre weighted the modern series properly, although McIntyre’s response that he could levy the same argument against Briffa is also valid (but not beside the point, as he states; it is entirely germane to the composite graph McIntyre created).
5. McIntyre’s focus on the decline in the sample number from 1990 on is almost completely misplaced. I say almost, because yes, it would be great to have a good sample right up to the present to see how the trees are tracking the instrumental record, and you can bet the Russians are collecting same. But that’s not McIntyre’s objection. Rather, he seems to think that low sample sizes in these years will strongly affect the RCS standardization procedure, when in fact it will have almost no impact at all, because there are already over 225 cores used in the RCS sample. This is because all cores are used in RCS standardization, not just modern cores. It is not clear that McIntyre understands this, or he wouldn’t be making such a big deal about it.
6. McIntyre, in spite of making 9 posts now on this topic, has still not explained exactly why he thinks non-homogeneity of tree ages through time is a critical issue, other than vague references to Briffa’s discussions of this issue. The vast majority of the series used were from short lived trees, so there’s not much Briffa could have done about that, and long lived modern trees allow an easier crossdating of the dead material, especially given the large percentage (5-10%) of missing rings in these trees.
7. Analogies of subsequent users of the Yamal chronology to crack cocaine addicts is completely out of line, and additional oblique references to the sloppiness of the science (“…But maybe this is a coincidence. One never knows – it’s climate science”), reference to “the Team” etc., further undermines the supposed neutrality of McIntryre’s position. The condescension towards Gavin and Tom P in his latest post, which is in fact a diatribe, essentially seals this.
8. The more appropriate place for this debate is in the peer reviewed literature. This should be obvious.
Does that help?
Tkearney (456) — I strongly recommend reading
“Plows, Plagues and Petroleum” by climatologist W.F. Ruddiman,
“Earth’s Climate: Past and Future” by the same author,
“The Long Thaw” by climatologist David Archer,
“The Discovery of Global Warming” by physicist Spencer Weart:
http://www.aip.org/history/climate/index.html
after Andy Revkin’s review:
http://query.nytimes.com/gst/fullpage.html?res=9F04E7DF153DF936A35753C1A9659C8B63
and maybe some of the other books found on the sidebar.
Rather than wasting patient Gavin Schmidt’s time. And, oh yes, he has a well-regarded recent book out as well…
Jonathan states:
“It does. By 1 degree for a doubling of CO2. No-one disputes that (well, some do, but not many).”
Actually the best estimates for climate sensitivity are between 2C to 4.5C for a doubling of CO2 concentration from the pre industrial value(~280ppmv).The IPPC gives values in the range of 1.5 to 4.5C.But the statistical distribution of possible sensitivities has a long tail at the high end, so there’s a significant possibility that the sensitivity can be considerably than 4.5C.
While the paper posted by Maikdev in 476 has something for everyone, it does have a nice explanation and a lot of references as to why using a large number of young trees in the calibration period to compare with the instrumental record is not considered to be a very good idea by dendrologists. Since even Eli was generally aware of these issues, there is no doubt that McIntyre is also. Thus, his injection of a mess of relatively young trees is, let us say cherry smashing.
Here are the relevant references
Briffa KR, Schweingruber FH, Jones PD, Osborn TJ, Shiyatov SG,
Vaganov EA (1998b) Reduced sensitivity of recent tree-growth
to temperature at high northern latitudes. Nature 391:678–682
Briffa KR, Osborn TJ, Schweingruber FH (2004) Large-scale
temperature inferences from tree rings: a review. Glob Planet
Change 40:11–26
Barber VA, Juday GP, Finney BP (2000) Reduced growth of Alaskan
white spruce in the twentieth century from temperature-induced
drought stress. Nature 405:668–673
D’Arrigo RD, Kaufmann RK, Davi N, Jacoby GC, Laskowski C,
Myneni RB, Cherubini P (2004) Thresholds for warming-
induced growth decline at elevational tree line in the Yukon
Territory, Canada. Global Biogeochemical Cycles, 18, GB3021.
doi:10.1029/2004GB002249
Wilmking M, Juday GP, Barber VA, Zald HSJ (2004) Recent climate
warming forces contrasting growth responses of white spruce at
treeline in Alaska through temperature thresholds. Glob Change
Biol 10:1724–1736
Vaganov EA, Hughes MK, Kirdyanov AV, Schweingruber FH, Silkin
PP (1999) Influence of snowfall and melt timing on tree growth
in subarctic Eurasia. Nature 400:149–151
Cook ER, Peters K (1997) Calculating unbiased tree-ring indices for
the study of climatic and environmental change. Holocene
7:361–370
Melvin TM (2004) Historical growth rates and changing climatic
sensitivity of boreal forests. Ph.D. thesis, University of East
Anglia
No, the argument is that you don’t ignore 2.5 million years of evidence, which appears to be what you wish to do.
Each of those theories was adopted because it explained more of the available physical evidence (observations) than available alternatives. Your suggestion that Newton, Einstein, Bohrs etc created their theories after having thrown out all available evidence is just bizarre.
Anyone have a link to a direct response/debunking to this from Ross McKitrick? http://www.financialpost.com/opinion/story.html?id=2056988
Re Tkearney @456, where in he cites a *news* story about MArtial polar melting.
I) This is a news item in National Geographic News. It is not a science paper published in a scientific journal.
2) But did you even bother to read the entire news item, or just jump at the headline?
3) For sure you did not follow the story forward in time, say to this follow-up two months later:
Mars Warming Due to Dust Storms, Study Finds
http://news.nationalgeographic.com/news/2007/04/070404-mars-warming.html
“I can easily follow the data.”
I doubt it, you can’t even find a news article.
#488 Jim Bouldin:
What Hantemirov and Shiyatov did to arrive at their 17-sample ensemble, and how it got whittled down to 12, is unclear. It is possible they were following “valid dendrochronological procedures”. The methods of sub-sampling were never disclosed. It is also possible that practises considered “acceptable” or “valid” by mainstream dendrochronologists are not, in fact, statistically defensible. That can not be judged without knowing how the sub-sampling was done. But while waiting for Dr. Briffa’s detailed reply, it is worth noting that Tom P’s analysis shows clearly that the smaller, but more extensive (we are told; we have no maps) CRU/Briffa chronology, now matter how you dice it, is quite different from the larger, but less extensive (we are told) Schweingruber chronology. The reason for the 20th century divergence in the two chronologies is not known, but it is the subject of a research grant held by Dr. Briffa. We must therefore wait patiently for Dr. Briffa’s reply. Meanwhile, perhaps it would be possible for someone versed in paleoclimatology to field these questions, since Dr. Schmidt is out of his domain and surely overworked? Excellent coverage of the issue.
Not that any of this matters, because the physics of greenhouse warming is beyond question.