Roger posted a comment on Ross’s discussions of the explosive Yamal tree ring issue. It’s well worth reading — particularly if you want the story stripped of any mention of precise statistical issues. (SteveM has been posting, but the individual posts generally include some analysis which can spread out the less technical tidbits which, in the case of this story, are just as important as the math.)
Anyway, I strongly recommend you go read Ross’s discussion at the National Post.
Update
It occurred to me I really like this quote (which I’ve partially edited to make more general)
Over the coming few years, ….. perhaps it will become socially permissible for people to start thinking for themselves again. In the meantime I am grateful for those few independent thinkers, like Steve McIntyre, who continue to ask the right questions and insist on scientific standards of openness and transparency.
One of the issues that gets lost in the whole “should we trust peer review” articles is this: Peer review is a first pass. In the full peer review process, people read articles. Then the ones who can think for themselves form their own opinions about the articles. They, they tell other people what they think.
These communications about published papers happen in both formal and informal settings. Historically, no one has said, “Oh. But who cares about Prof. X’s opinion about paper B. He only said it in a conversation at a conference. Until he writes a journal article, I’m not going to pay attention to that opinion.”
In reality, even if Prof. X thinks paper B is absolute drek he will likely never write a paper of comment for many reasons. One of them is: He doesn’t want to derail his own research to spend time composing, proof reading, and submitting a comment, and then slogging through the review cycle. The same holds for numerous scientists in industry or across the world.
All know that in the long run (which may be any amount of time between now and 50 years) bad research will drop off the radar and be replaced by good research.
Blogs are nothing more than a new informal setting. Now, some people who can think for themselves quickly post what they think and why. Readers can decide which bloggers seem credible and which do not. They can form their own reasons for finding a particular blogger credible or not.
And readers will do this.
I loved the add on Lucia. I also latched onto that quote when I read his article.
People don’t need peer review to understand that sorting through data for the series you like is not a good or honest practice. We already know.
Will scientific doubt about extreme warming become widespread in time to make a political difference? I have read that the EPA has announced it will immediately impose CO2 emissions reductions, treating CO2 as an air pollutant, if Congress does not enact cap and trade legislation this year. So long as Congress does not explicitly forbid such action by the EPA (by passing a specific law against regulation of CO2, or explicitly forbidding expenditures by the EPA to enforce CO2 emissions rules), then I fear the science will no longer matter, at least until control of congress changes hands… and who knows when that might happen.
JeffId
Correct. We don’t yet know Briffa’s reasons for selecting that series. Ideally, the fact of down-selecting would have been revealed during publication either because he said it or because the reviewers asked. Then, the reason would have been given at that time.
If so, we could go back, read it and decide what we think. But… they weren’t. And the fact that data weren’t archived meant no one asked about the reason for selecting the subset for years. So.. … Were Briffa’s reasons good? Bad? Indifferent? Anyone can tell the reasons matter. But we can’t really know what they are until Briffa explains.
SteveF– Putting on my psychic hat, think the EPA will end up imposing reductions. This will have political and economic fall out. Afterwards…. who knows? Midterm elections are in 2010….
I thumbed thru EPA’s analysis of Waxman-Markey and it does not appear to me that even with massive fuel price increases, any of this would make any climate difference.
My back of the envelope calculations say that even if the US banned all CO2 emissions from all fossil fuels for ten years, that would not knock off even a tenth of a degree C from the global avg temp.
I think the EPA should be required to generate a dollars per One Degree C reduction figure for any regulatory proposals.
For all the interesting discussion of dendrochronology, there are also a lot of folks who just jump on things because they support their position on the debate (see most of the press coverage on this, for example).
One of the benefits of the peer review process is that it enforces a certain professional courtesy, as most journals tend to frown on explicit snark.
Lucia:
One of the fun implications of a potential EPA regulation would be that a supermajority would be needed to override a presidential veto of any bill removing the EPA’s authority to regulate carbon, so I’d suspect that little would change no matter how 2010 elections end up. That said, I doubt that the EPA will actually impose regulations, as I think congress will eventually pass something (and, frankly, the EPA is lighting a fire under them). Given the polling numbers on the climate bill, its not nearly as politically charged as, say, health care is at the moment.
Zeke,
“there are also a lot of folks who just jump on things because they support their position on the debate”
Is this akin to people picking data that support a pre-determined conclusion?
Andrew
Andrew_KY,
It would. However, Steve M is not accusing Briffa of picking data that support a pre-determined conclusion, given that he got the dataset from Hantemirov and Shiyatov who chose that set for a specific reason unrelated to their effects on the end result.
lucia,
Great comment at Benjamin Hale’s Cruel Mistress blog. I am pleased to see you are following this story closely enough to get all the facts straight.
Zeke,
We really do not know how/why the data set was chosen by Hantemirov & Shiyatov, nor what if any additional selection was made by Briffa, since he has not addressed this.
We do know that there were other (larger) and apparently more suitable data sets available for the same geographical region which were not used by Briffa. We also know that the H & S paper based on their complete data set for the region (of which Briffa’s Yamal data is only a subset) did not show any extreme warming in the 20th century. There is no reason not to wait for Briffa to offer a more complete explanation, but I hope you agree that the available information suggests the Briffa paper stands on very thin ice (due to global warming?).
I hope you also agree that Briffa owes everyone a prompt and complete explanation.
Zeke
Sure. This cuts both ways on every topic.
Sure. And maybe this is important, or maybe it’s not.
Certainly, this benefit is dispositive with regard to figuring out who is correct or incorrect on a point.
It’s also the case that peer review has positives and negatives. Within fields, conferences, poster sessions and other forms of communication can get around some of the negatives. Authors who wish to advance unpopular but interesting results who present material can often find editors and reviewers who view their work favorably and submit their work to journals with friendlier editors. This is a known practice.
But this doesn’t work well for outsiders whose employers don’t foot the bill to travel to a conference, stay in a hotel, pay conference fees and present their work.
These people can blog. Yes. They are sometimes snarky. But their views are aired. Sometimes, snarky or not, the bloggers are correct.
Anyway, in the Steve vs. The Team exchanges, I’d say there is snark on both sides. So while I can sympathize with some scientists who may have tender feelings and who don’t indulge in snark, I can’t …. exactly…. sympathise when scientists who sling snark at their blogs complain about being on the receiving end of a snarky volley. They should just learn to put their big boy pants on.
Zeke,
“One of the fun implications of a potential EPA regulation would be that a supermajority would be needed to override a presidential veto of any bill removing the EPA’s authority to regulate carbon, so I’d suspect that little would change no matter how 2010 elections end up.”
I’m not certain where you think the fun is in this observation.
It is certain that Congress does not need a super-majority to control what the EPA does. A simple majority of Republicans in both houses would make life sufficiently difficult for Mr. Obama that he would be forced to compromise on a whole range of issues. Congress does not need to override a veto to stop an EPA regulation, they need only refuse (in whole or in part) to fund the EPA in the next budget. When such a funding reduction is threatened, the agency has no choice but do as Congress wants. I don’t think Mr. Obama is going to fall on his sword over carbon emissions regulations; he will have bigger issues to worry about.
bender–
Yes. There are a number of reasons I held off on blogging. One was I was busy. The other is that I’m not familiar enough with the statistical details, the specific choices of proxies etc. Getting familiar would involve huge amounts of time, and I’d rather do other things.
But there are some things that have nothing to do with statistics, specific choice of proxies. They are more general.
The problem for some of the blogging climate scientists is that they are on the wrong end of the stick on those.
SteveF: On H&S not showing recent warming, Steve M commented that:
“…the H and S method would be unable to recover centennial scale variability and that it was not relevant to the issues at hand.
The H and S reconstruction does not “support†my point in respect to Yamal. It’s irrelevant to it.”
Lucia,
I agree with your notions that blogs are just another form of informal discussion—one that has a lot larger audience than conversations at a scientific conference or in a departmental seminar. But as a (sometimes) eavesdropper on (potions of) these conversations, it is hard for me to know what the significance of them may be. And given the din of a blog, it is hard to follow the original topic very far anyway.
Jeff Id comments that “People don’t need peer review to understand that sorting through data for the series you like is not a good or honest practice. We already know.â€
I guess that means that a large potion of my scientific work has been neither good practice nor honest as I have on many occasions, employed exploratory data analysis techniques including multiple regression and my intuition as to what variables may impact another—I sort of thought that’s what applied climatology was all about. When I was trying to develop a yield model for crops in Virginia, I collected a bunch or weather variables that I thought may be related to crop growth (and excluded a bunch that I didn’t think were related), then I “sorted through the series†I had looking for series that I “likedâ€â€”i.e. ones which had a relationship with crop yields. Then, with the series in hand that I liked, I built statistical models of soybean and corn yield for each climate division in Virginia. This was a procedure that I employed over and over again as I explored many different topics. Funny thing is, is that I based these techniques on peer-reviewed methodologies (as well as the procedures I learned in stats class)! I’d hate to try to imagine how to construct a statistical model that included every variable known to mankind—but I know well and good what the result would be—nothing! (far too much noise ever to find a signal)
While I appreciate the contribution that blogs make (and I rely on them from time to time to gather information for my internal processing of a particular idea), I prefer to read about the science in the peer-reviewed literature. I, for one, haven’t the faintest idea what Steve McIntyre’s recent find means for our overall understanding of how the earth’s average (or should that Northern Hemisphere, or should that be high latitudes) annual (or should that be summer, or should that be growing season) temperature has varied over the past 600 (or should that 1000, or should that be 2000) years. Too many details, scattered all over the place (many on the midst of a lot noise) for me to keep up with and sort out.
Write it up, publish it, and then let me ponder the results in a controlled format. Then I can go to the blogs, conferences, seminars, colleagues, for reactions and discussions, if I want them. I use peer-review to follow the evolution of scientific knowledge—blogs only give me an insight as to what might be coming down the pike. But if it never makes it out of the blogosphere, then it does me (and my assessment of the accepted science) little good. Hopefully I’ll soon be reading (and citing) Jeff’s work on Antarctic temperatures!
-Chip
Zeke/SteveF
The issue of presidential vetoes is also complicated. Yes. Congress needs a super-majority to over-ride vetoes. But vetoes get a lot of press. And if the EPA’s actions become very unpopular, then Obama would be expending quite a bit of political capital when vetoing any bill. (That is, unless he has the good fortune to get a pocket veto.)
Obama has been popular, but that popularity has been Would he spend his political capital to veto a bill that modifies the power of the EPA? For climate? That’s difficult to foresee.
Of course, if or when the time comes, American voters want the EPA to regulate CO2, this issue of political capital would be moot. In that case, he would gain political capital by vetoing the bill.
Midterm elections are coming up. I can’t guess what will happen then. But our system has short terms for members of the House, and we’ll see what happens then.
It does really depend on how popular/noticeable the EPA’s actions would be to the average American. Generally polls seem to show general favor for action on climate (e.g. http://www.washingtonpost.com/wp-srv/politics/polls/postpoll_081909.html?sid=ST2009082800547), though that shifts if they have to pay $25 a month more on their utility bills (they seem to be fine with $10).
Zeke–
Yep. The level of popularity will depend on how much it affects people’s bills.
It may also end up depending on whether or not they believe companies extra payments result in higher prices for goods. I don’t have a poll… just know that people tend to be price sensitive about nearly anything.
Zeke,
Did you read the H & S paper? I suggest that you look at figures 10 and 11. Figure 10 shows the frequency of extreme low and high summer temperatures relative to the entire record, and shows nothing unusual happening in the 20th century. Figure 11 shows a temperature reconstruction for the entire data set using a 60-year low-pass filter. While it is true that this 60 year filter would not show very long term changes very well, it is clear from the graph that there was nothing unusual going on in the 20th century compared to the remainder of the record.
Do you not agree that the Briffa paper stands on very thin ice?
Do you not agree that Briffa owes everyone a prompt and complete explanation?
The topic of the EPA and Clean Air regulations has come up: what interests me is that the EPA is inserting itself into the legislative process. My take on our constitution is that Congress alone is responsible for writing the laws of the land. The EPA was created to administer the laws – in this case as specified in “The Clean Air Act” (CAA). The EPA has decided itself to interpret the CAA to consider CO2 as a pollutant, which was never specified in the original act. The simplest thing Congress could do is to pass a Bill removing CO2 from consideration under the CAA and then game over for the EPA regulations. I am waiting for any minute now for the Senate to wake up and ask itself why it is letting itself be pushed around by the EPA.
The level of popularity of CO2 controls will also depend on the weather. If there are controls applied that boost energy prices at the same time that there is an unusually cold winter, then the political reality of millions of angry voters would be hard to ignore…. “I’m paying extra to heat my house so that I can be sure it gets even colder?”
In Climate Science, …
There is no peer review process.
There is only a “peer pressure process”.
Chip–
Agreed on all points. Obviously, it is worth publishing useful results in peer reviewed journals for many, many reasons.
On the crop yields. Obviously, with respect to weather variables, you picked values you “liked”. But presumably, you didn’t then go hunt around every single farmer’s crop in Virginia to find which famers’ field gave the correlation you “liked”. So, there is picking, and there is picking.
We don’t yet know precisely what is going on with Yamal. On this issue, there really will need to be some formal publications where the full argument is organized and presented. Few people are going to try to follow the story blog-post-by-blog post. That just doesn’t work.
Lucia,
“We don’t yet know precisely what is going on with Yamal.”
Before Steve Mc’s discovery, did we know ‘what is going on with Yamal’?
Before Steve Mc’s discovery, did someone claim they knew ‘what is going on with Yamal’?
How has our knowledge changed regarding ‘what is going on with Yamal’?
Andrew
Andrew–
Previously, some thought we knew what was going on with Yamal.
We now know that we don’t know what is going on with Yamal. 🙂
Chip,
Of course its ok to do sensitivity analysis to discover what the most significant drivers are for cause and effect, but that does not appear to be applicable to the particular issue brought up by McIntyre on the Yamal series. There has been no explanation for the extremely small tree ring sample for 20th century data in the Briffa study.
The New Atlantic: Rethinking Peer Review
http://www.thenewatlantis.com/publications/rethinking-peer-review
“We now know that we don’t know what is going on with Yamal”
Indeed. ‘We’ know now that ‘we’ didn’t know it then. Some of ‘us’ knew already that ‘we’ didn’t know it. 😉
Andrew
Chip, forgive Jeff Id for being a bit reckless with his wording, but he has demonstrated the effect he speaks of here:
http://noconsensus.wordpress.com/2008/10/11/will-the-real-hockey-stick-please-stand-up/
In addition, a comment was posted in Science about the use of a similar algorithm in Briffa Osborn 2006(and perhaps by you.)
http://www.sciencemag.org/cgi/content/full/316/5833/1844a
“given the large number of candidate proxies and the relatively short temporal overlap with instrumental temperature records, statistical testing of the reported correlations is mandatory. Moreover, the reported anomalous warmth of the 20th century is at least partly based on a circularity of the method, and similar results could be obtained for any proxies, even random-based proxies. This is not reflected in the reported significance levels”.
Semi-related question.
Does this impact the potential views on feedbacks? If we’ve seen similar variations in the past as we are seeing modern times, and obviously they were not caused by co2 back then, and there was no runaway feedback loop at any point, does that potentially undercut some of the high feedback models?
Thoughts would be appreciated. 🙂
JK–
I’m sure there are people who will say it does impact our understanding of feedbacks. But the arguments are fairly involved. It goes without saying they also assume that we understand all the mechanisms involved in forcing the climate, and assumes a number of other things. It also assumes the paleo reconstructions work at all.
If the finding is that the paleo reconstructions are simply too uncertain to permit us to know the temperature as as far back as 1000, that will tell us knowing about feed backs. It will simply mean ‘we don’t know what the supports of the hockey stick claimed we know’.
Some times, science does to from “We used to think ‘X’, based on evidence ‘Y’. Evidence ‘Y’ turned out to be dubious, so now we don’t know ‘X'”. After that, all other conclusions based on ‘X’ become more tenuous.
About EPA comments.
There are some misconceptions posted. First, the EPA is requiring that entities covered by appropriate, per law, environmental regulations to start reporting amounts in (lbs/tons/accepted measurements) of greenhouse gases. Scheduled for 2010 to be done in 2011. This should alert persons to the fact that the EPA is considering the science from the fact they did not center on CO2, nor think that one should make large scale proposals without getting a measure of the potential problem.
Next, some do not understand that regulatory agencies are REQUIRED to propose regulations that effect health, or other mandated, by law, items of concern. That the EPA “found harm” may be objectionable, but findings of harm are consistant with what has been published. Even though the EPA has some excellent analysts, see their UHI info, they are REQUIRED to use and CREDIT current scientific positions.
That the EPA is progressing is professional in the sense that it was ruled by the US Supreme court that the EPA could address CO2, GHG’s as brought to suit. They are doing their jobs.
Yes, as with “ergonomics” regulations, Congress can tell a regulatory agency to “reboot.” It is not necessarily up to the executive department. If the regulations are unopposed, they are considered “to carry the force of the law .” Congress enacts law, not the EPA nor Obama.
I do not know if it has been decided, but if Obama directs the EPA to do something, and Congress opposes it, it is ASSUMED not to carry the force of law, since Congress enacts law, the excutive department carries out the law. This assumption could run afoul of the court for all I know, since both would claim “legality”.
Please keep these items in mind when assigning attributes or “facts” to the EPA.
John F. Pittman (Comment#21091)-The EPA’s finding was more abuse of scientific literature than use:
http://www.cato.org/pubs/articles/michaels_ANPR_EPA.pdf
Hey Andrew Fl don’t know how you can comment when my clock says I still have time to edit. However, I will comment. From the Cato report “We seek comment on the best available science for purposes of the endangerment discussion…The reasons why the EPA should not rely on the IPCC AR4 reports are made obvious in comments in Part I of this submission.”
Whether CATO, you, or I, don’t like it, the IPCC and more importantly the USCCSP have been accepted indirectly, or directly to have the best synopsis of the science. I do not agree because of problems that have been documented. However, in that the EPA has to use their expertise and MUST use science as it is done. That you disagree with what the best science is, well hate to tell you, but that has not been decided yet for or against your position. However, the EPA does have to take what is available and decide. Their decision may be wrong. That is different than saying that they did not follow procedure. I personally and professional think that AGW is overblown. Using the same criteria, I think the EPA has discharged its duties acceptably, and more importantly, the record will support this conclusion.
If you want perfection, I dare say you must wait for the next life. This mortal world is obliuosly not perfect IMHO. Nor did the EPA claim such, nor CATO make it a researched legal requirement.
Anthony Watts (http://wattsupwiththat.com/) has reported Keith Briffa’s response (initial response at least) to recent remarks on selection of Yamal tree-ring data. Anthony re-posted material from
http://www.cru.uea.ac.uk/cru/people/briffa/yamal2000/
But McIntyre specifically says he hasn’t accused anyone of doing anything. “Playing with the data” means he is accusing the scientists of fraud.
Bugs if you are going to attribute it to SteveM or even Ross, please do so. Your link can be interpreted to be from the person, NP Editor, who posted this, not Ross or Steve. See below from your link.
Ross McKitrick: Defects in key climate data are uncovered
Posted: October 01, 2009, 9:03 PM by NP Editor
climate change, hockey stick, Ross McKitrick
Only by playing with data can scientists come up with the infamous ‘hockey stick’ graph of global warming
Read more: http://network.nationalpost.com/np/blogs/fullcomment/archive/2009/10/01/ross-mckitrick-defects-in-key-climate-data-are-uncovered.aspx#ixzz0SpZbE1A7
Please show this is from Steve and how stating “playing with data” means fraud. Many of us “play” with data all the time. Fraud indicates you did not play legally or ethically, not that you played with data morally or correctly.
Makig fun of how someone plays with data is just making fun, not an accusation of fraud.
bugs–
1) Ross wrote the article that runs under that heading, not steve.
2) The NP editor may have written the prefatory materials. So, that quote may be neither Ross nor Steve but the NP editor.
3) Does playing with data imply fraud? That’s a pretty common expression and often used without implying fraud. Some people may think playing with data is required to find the truth.
The policies based on the false claims of AGW will be at least as destructive as badly done medical reform.
If we permit bad science to be the basis, as now appears, for the destruction of our energy infrastructure, we will pay a huge price.
Even if the elections of 2010 were to produce a change in both Houses of Congress, would the new leadership be tough enough to defund the bad policies the EPA is likely to come up with in the next few months?
Nothing short of literally removing by budget the ability of the EPA from further CO2 regulation would work. The very bad Supreme Court ruling that allowed five lefty judges to pretend CO2 is a pollutant, makes even defunding the EPA problematical. AGW promotion groups like Geenpeace could probably sue and force the government under court order to still do ridiculous things to energy production. Perhaps nothing short of an Andrew Jackson telling the Supreme Court to enforce their own rules, and to break their judicial stranglehold will help.
The lessons of never again permitting a peer review system to breakdown will hopefully be learned from. The cost we have already paid for AGW is high and will only get higher, before this is done.
George Tobin,
You have defined the madness of cap-n-trade perfectly.
It is a complete and total scam. It is does literally nothing for climate, jobs, American security, or the environment.
John Pittman,
McIntyre gets the ball rolling, with comments such as
“In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection”, 2) “It is highly possible and even probable that the CRU selection is derived from a prior selection of old trees”, 3) “I do not believe that they constitute a complete population of recent cores. As a result, I believe that the archive is suspect.”
http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/
His buddy McKitrick goes far beyond such “subtle” innuendo.
“Thus the key ingredient in most of the studies that have been invoked to support the Hockey Stick, namely the Briffa Yamal series, depends on the influence of a woefully thin subsample of trees and the exclusion of readily-available data for the same area. Whatever is going on here, it is not science.”
“I have consistently found that when the layers get peeled back, what lies at the core is either flawed, misleading or simply non-existent….and as I have detailed elsewhere the IPCC fabricated evidence in its 2007 report to cover up the problem. ”
http://www.financialpost.com/opinion/story.html?id=2056988&p=3#ixzz0SnxlaZRq
It gets even worse as you move on to WUWT, Telegraph, etc.. Admittedly, it doesn’t take much to get the conspiracy ball rolling among certain political circles.
One might hope that “skeptics” who spend much of their time slandering scientists in politically-charged op-eds and shrill blog posts would turn off objective observers. But the incentive to make these sorts of unsubstantiated claims is strong, since there is a crowd of folks who eagerly digest this sort of stuff, as one can see in the comments sections of these blogs and in dubious media outlets (Telegraph, Financial Post, etc). It seems unlikely such attention would be apparent if the individuals involved simply engaged in a straight discussion of science, and kept such potential discoveries in their proper context. Casually alleging or implying fraud seems to be so much more rewarding for some.
Briffa’s objective response, calm in tone, in contrast, is what one would expect from someone without an agenda.
Quite frankly, I worry that all the childishness and personal horn-tooting from “skeptics” regarding every gross distortion of climate science and implications of some alleged discovery is going to ultimately tar skeptism. What will we think if a serious legitimate contentions with genuinely strong implications ever arises, when “skeptics” have cried wolf so many times?
“Casually alleging or implying fraud seems to be so much more rewarding for some.”
I can attest to this. Personally, I get a rush every time I see fraud (like AGW or someone sending me a ‘Not A Check’) and I point it out.
AGW is a fraud.
That felt really good. 😉
Andrew
NewYorkJ,
Those quotes that Gavin posted,
“In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection”
Here is what Steve McIntyre wrote at ClimateAudit
“In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection – in this respect, perhaps and even probably by the Russians.”
Does this strike you as ‘cherry-picking’ to achieve a desired result?
So NewYorkJ we are back in that laager again if somebody questions a CAGW sermon we call them “skeptics” (note the inverted commas to imply that it is a mask for hidden motive — which conspiracy kettle is doing the black calling now?). Briffa refused to reveal his data until his pride got the btter of him and he published in the Philosophical Transactions of the Royal Societywhich meant he had to and the sandy foundations were exposed. Of course Steve M is snarky and suggestive he has spent the last 10 years having his motives and intelligence attacked.
Is NYJ hitting and running?
…and I was in a New York State Of Mind tonight. 😉
Andrew
MikeN: “Here is what Steve McIntyre wrote at ClimateAudit
“In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection – in this respect, perhaps and even probably by the Russians.â€
Does this strike you as ‘cherry-picking’ to achieve a desired result?”
Ah…the Russians are in on it too. If you blindly trust McIntyre’s “opinion” (which is rather dubious and unsupported by objective analysis…in my opinion), perhaps you might come to that conclusion. I’ve noticed that many of his readers don’t seem to understand much of anything about the issues involved with proxy evidence (dendroclimatology or what not). What draws them to his site (WUWT probably more so) is that they regularly read a few words implying some scientist is hiding something or manipulating data and perhaps a few odd jabs at Al Gore, a few people yell “fraud!” and the frenzied parroting begins. Suddenly a rather mild mostly inconsequential scientific issue at best and meaningless at worst becomes a great debunking of hockey sticks and climate science. When the frenzy dies down, the dust settles, and the Skeptic Emperor is revealed to have no clothes, another question is raised and the process begins again.
Andrew23,
Speaking of sermons, Pastor McIntyre appears to have taught you well. If you seek truth (it’s always good to assume good faith), be willing to be skeptical of the “skeptics”. The site below is one place to start if you’re having trouble.
http://www.skepticalscience.com/
Purpose:
“Scientific skepticism is a healthy thing. Scientists should always challenge themselves to expand their knowledge, improve their understanding and refine their theories. Yet this isn’t what happens in global warming skepticism. Skeptics vigorously criticise any evidence that supports anthropogenic global warming and yet eagerly, even blindly embrace any argument, op-ed piece, blog or study that refutes global warming.
So this website gets skeptical about global warming skepticism.”
Have a good weekend.
Lucia:
“Does playing with data imply fraud? That’s a pretty common expression and often used without implying fraud.”
I think if you say in the same sentence that the results are “infamous”, it doesn’t imply just playfulness.
Steve M introduced his main post on this with the sentence:
The second image below is, in my opinion, one of the most disquieting images ever presented at Climate Audit.
What do you think he’s talking about?
Someone who is in no doubt is Andrew Orlowski, whose Register report,, under the heading “A new scientific scandal” was featured in a post at CA The Register picks up the Yamal story. Orlowski said:
I think if you get posts appearing on WUWT saying Briffa should resign, something has been implied.
“The second image below is, in my opinion, one of the most disquieting images ever presented at Climate Audit.”
Indeed it is. Because there was no mention of other tree records from the same site and no mention about why especially these Chosen ones were chosen over the rest. And related to the 10-years od non-archiving since tyhe publication, it does not paint a pretty pircture. I would expect something along the lines of: ” There are N tree cores available taken from the site, but we have chosen X of these because of….”.
New York J,
YOu mean that it is OK for AGW leaders like Hansen to call for the criminalization of climate dissent, and it is also OK for Briffa to with hold evidence for many years, but it is not OK for skeptics (why the ‘ ‘?) to doubt their integrity? Do you think what passes for peer review in AGW land is one of integrity?
Too bad, fella. Your side has earned what is going to come, in spades.
It is a shame that NIck and NewYorkJ are as skeptical of all, themselves, RC, etc, as they complain. From misquoting to fabrication of what SM has said, implying (by their definitions not mine) that SM is somehow responsible for posters at WUWT whrn he has specifically and numerously cuationed about going a bridge to far, and in particular has censored “fraud” from his blog.
However, for all your talk, Nick and NYJ, the small size of the sample is known to be an incorrect application of the RCS methodology for making claims as to what it shows. Nothing the Russians did was contrary to this. They did their paper with a different purpose in mind. I fail to see how Briffa et al’s failure to understand the limits of the method they chose implies how SM, Anthony, or the Russians are somehow responsible.
I fail to see how SM is responsible for “”I’ve noticed that many of his readers don’t seem to understand much of anything about the issues involved with proxy evidence (dendroclimatology or what not). “” Besides this is somewhat a strawman since SM is posting about incorrect application of methodology and statistical inferencing.
It is though the two of you are stuck in the past prior to the North NAS panel and the Wegman report. Correct application of the methodology and correct statistical inferencing are a REQUIREMENT for a process that is meaningless without the correct inferencing and procedure(s). One of the most important is your DATA. No one is responsible for the data but Briffa et al. It was their paper; their burden of proof.
NYJ,
“Briffa’s objective response, calm in tone…”
I didn’t like Briffa’s tone. I thought it was too dismissive, so therefore he must be wrong. 😉
His tone? Your argument/defense is (partially) based on his tone? Please tell me you aren’t serious.
Andrew
Nick–
Bug accused Steve of accusing Briffa of fraud. I don’t see how
a) what people at WUWT who are not steve’s saying can turn steve non-accusations of fraud because accusations of fraud.
b) how saying an an image is disquieting is an accusation of fraud or even
c) how calling the hockey stick graph makes playing with data become an accusation of fraud or
d) how the editor who is not Steve writing a blurb for Ross’s article where the editor (not steve) calls the hockey stick “infamous” makes Steve guilty of accusing Briffa of fraud.
Steve has described a series of events. The events occurred.
Other people read the events. Some who are hasty and don’t consider the full range of possibility are accusing Briffa of fraud. But Steve hast not accused Briffa of fraud.
Nick: “Steve M introduced his main post on this with the sentence:
The second image below is, in my opinion, one of the most disquieting images ever presented at Climate Audit.
What do you think he’s talking about?”
I think he explained himself in the rest of the post, eg.:
“Briffa’s own caveats on RCS methodology warn against inhomogeneities, but, notwithstanding these warnings, his initial use of this subset in Briffa 2000 may well have been done without fully thinking through the very limited size and potential unrepresentativeness of the 12 cores. Briffa 2000 presented this chronology in passing and it was never properly published in any journal article. However, as CA readers know, the resulting Yamal chronology with its enormous HS blade was like crack cocaine for paleoclimatologists and got used in virtually every subsequent study, including, most recently, Kaufman et al 2009.”
Do you think McIntyre is responsible for other interpretations – on other blogs?
Is it surprising to see comments from suspicious minds when data has been withheld for a decade? I think not.
NewYorkJ (Comment#21102)-Why exactly does RC disingenuously half quote Steve out of context? In this case this is indeed what McIntyre said BUT IT IS ALL HE SAID:
““In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection—
In the words of Rep Wilson: “You lie! [by omission]” The full quote is:
““In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection – in this respect, perhaps and even probably by the Russians—
It seems that the only one who is not adequately skeptical here is the one thumping his RC and SS bibles-you are so trusting, and yet look, outright deception on the part of your “scientists”.
Seeing as Hamlet and RC ‘petards’ have been mentioned elsewhere: methinks [misquote] they doth protest too much.
The utter fraud of torturing McIntyre’s sentence fragments, inquisition-like, in order to assert that he’s alleging fraud… these are scientists, Jim, but not as we know it.
Nick Stokes (Comment#21126),
“I think if you get posts appearing on WUWT saying Briffa should resign, something has been implied.”
Nothing needs to be “implied” by Steve M or anybody else. Briffa’s behavior in 1) refusing to release data (despite repeated requests), 2) non-compliance with data archiving requirements of several journals, 3) releasing the Yamal data only when forced to by the Royal Society, and 4) releasing it without meta-data and in a format that would make reconstruction of his work more difficult, all obviously imply Briffa was hiding something. Steve M has shown that the data is at best extremely suspect, and more likely, completely unsuitable for the analysis method Briffa used. This result is not surprising in light of Briffa’s refusal to disclose the data.
Most little kids can detect behaviors consistent with someone who is being less than honest; why can’t you?
NewYorkJ, you misunderstand my accusation of cherry-picking.
Here is the quote Gavin posted, and you reposted
“In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selectionâ€
Here is what Steve actually wrote, compare the two
“In my opinion, the uniformly high age of the CRU12 relative to the Schweingruber population is suggestive of selection – in this respect, perhaps and even probably by the Russians.â€
Now does this strike you as a fair quote by Gavin(and you), that represents what Steve said, or do you think Gavin was cherry-picking to make Steve look bad. Noone is accusing the Russians of anything, as far as I’ve seen.
Andrew,
I thought Briffa’s tone was exactly like that of a bureaucrat who got dodging after ten years of deception: Banal, arrogant, and evasive.
The real question worth asking is this:
How much more garbage data has been used to sell extreme AGW scenarios and to frighten millions of people and their leaders, and to enrich AGW profiteers?
Actually, my opinion is that Briffa unintentionally (?) supported SM’s work. From Briffa’s post: “My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data. “” An equal reading of this is “We have not developed robust methods for expressing the evidence of climate changes using tree-ring data.” This agrees with SM’s complaints about the “disturbing” nature of what he found. As Steve humorously pointed out, it became like crack coke being used about once a year for a decade. I would also point out that, IIRC, contrary to a claim at RC where they implied or stated that the number of times a peer-reveiwed work was quoted or used indicated its correctness, the history of citation being useful are contra-indicated by Briffa’s statement that robust mehtods are in develpment. The results have not presented as non-robust.
hunter,
“How much more garbage data…?”
As much as they can get away with… as is usually the case with criminals.
I’m also a little hesitant to rule out the ‘cry for help/wants to get caught’ scenario. But of course, that’s just speculation on my part. 😉
Andrew
SteveM is looking for a measured debate about the [lack of] methodology underlying the [questionable] scientific work of one of the more influential Team members.
Some will use his analysis for “political” purposes, just as the other side has used Briffa’s and the Team’s “research” as proof positive of “unprecedented” high global temperatures caused by man’s use of hydrocarbon energy sources.
As recently demonstrated in a Political Science PhD thesis submitted at my old alma mater, Lund University in Sweden, reality is that in that country, the political elite across the spectrum made up their collective minds 20 years ago that humans are the cause of global warming, and after that paid no attention whatsoever to anything that might suggest anything else, from real world data to different hypotheses.
The same thing happened within the federal Liberal Party in Canada, one of whose “eminence grise” operators, Maurice Strong, was not only instrumental in the set-up of the IPCC but around the same time also in re-populating the senior levels of Environment Canada [aka the ministry of the Environment] with AGW/ACC proponents.
Science does not drive politics, it is merely subverted to bolster positions. We do know for sure, however, that politics do drive science, in particular “climate science”.
Jeff Id over at tAV said it very well in his post -RC Off the Deep End-
“So the possible sorting of data suggested in the quotes given — is actually standard practice.”
Gavin’s rants over at RC about accusations of cherry-picking are oxymoronic in the extreme. The whole approach of cherry-picking proxies because only some have a positive correlation with measured temperatures invalidates the whole mess.
Its PaleoRorschachism, a new psychosis.
So much of Gavin’s, et al, attack depends on snark, nuance, clever parsing, close reading, reading of minds and motives, but Gavin is not a credentialed, peer reviewed, professional parser. Why he’s no more qualified to venture into that realm of inquiry than, apparently, Mr. McIntyre is to trod the hallowed ground of climate science, especially of the AGW flavor.
As a formerly professional, credentialed, and peer reviewed parser, I humbly offer my services, but conscience demands that I offer this caveat. We professionals sneer at the odd comma splice, and blather in general. Climate Science should step carefully into the cave of professional parsers. The path is littered with pretenders. In fact, we’ve noted a hockey stick shaped uptick in puerile parsing that, oddly or not, fits perfectly to Mr. Gore’s quite Inconvenient Truth.
Have not been here for a while. Skimming through the comments (so I may have missed previous responses), a few points:
1)Briffa’s criteria for the selection of sites/trees to take core data from are clearly enough described in his papers.
2)Briffa’s criteria for the selection of chronologies are also clearly stated in his papers (or their SMs).
Now he might have done a bad job of the above or he might have done a good job. Some papers are good, some are not. But attacking a dendroclimatologist for doing what dendroclimatologists do is just dumb. If you don’t like dendroclimatologists looking for sites/trees that are likely to exhibit a temperature signal, or selecting chronologies that can be validated, then I guess you don’t like dendroclimatology.
“I guess you don’t like dendroclimatology”
I don’t know Simon, what useful information has dendroclimatology produced?
Andrew
I don’t know Simon, what useful information has dendroclimatology produced?
Andrew
Well, it seems to have confirmed an anomalously warm period in NH locations during the MWP. Is that useful? I don;t think it’s vitally useful, but it’s interesting. I think it contributes to our understanding of climate sensitivity and, potentially when we have more studies, of the millenial variation in regional climate.
It is not able to distinguish anthropogenic warming from natural forcings as yet, so it doesn’t help us much at all with attribution.
I think it’s useful science, yes, but I don’t think it’s very essential to the debate that prevails here.
“Well, it seems to have confirmed…”
Simon,
In the interest of scientific discussion, I think ‘seems to’ isn’t good enough. Either it actually confirms something or it doesn’t.
Andrew
In the interest of scientific discussion, I think ’seems to’ isn’t good enough. Either it actually confirms something or it doesn’t.
Ok, then, it’s confirmation of a warm MWP in NH locations is of no value! And, by the same token, Loehle’s reconstruction is of no value, and historical evidence is of no value, so thank you very much – you just got rid of the MWP! 😉
“you just got rid of the MWP!”
Woo hoo! And I wasn’t even trying. Doesn’t take much to get rid of it, does it? 😉
Andrew
Hee hee 😉
But I think you’ll take my point, that whatever the limitations of proxy evidence of one kind may be, there are equivalent limitations to all proxy evidence. It simply isn’t persuasive to ‘talk up’ one type of evidence (such as my great grandmother x 10 passed on that she used to grow grapes in Greenland) whilst ‘talking down’ another type. And I’ll posit the view that Briffa’s tree ring chronologies are a darned sight more robust than stories about the Chines sailing through an ice-free Arctic, no?
But maybe it’s all useless and we have no surety of what the climate was like back in 1100 across the globe. In which case getting rid of the MWP was a con but also positing it in the first place was a con.
“And I’ll posit the view that Briffa’s tree ring chronologies are a darned sight more robust than stories about the Chines sailing through an ice-free Arctic, no?”
How do you know they are more robust?
“In which case getting rid of the MWP was a con but also positing it in the first place was a con.”
Not necessarily. It depends on what the evidence is produced for each. You can’t just dismiss both or one or the other or neither without looking at the evidence.
Andrew
Ha Ha Simon — I don’t like your idea that all evidence is equivalent, if you think about that for a bit if we follow this path all evidence is a con and all we can conclude is that we don’t know anything — we don’t know that unusual warming has occured nor that it hasn’t. We will be paralysed by indecsion. We must put some value on the evidences. In this case most historical evidence suggests some type of MWP but its strength or spread are hard to asess. Archeological evidence supports the historical. Treechronology has had some success in caes and all else being equal makes biological sense, so can it confirm or deny MWP? Initially it seems to deny so do we drop the historical? Depends on the value we put on each piece of evidence. The treechronology seemed ok until the full data set was revelaed and then it seems to have less strength than the historical so the MWP is back on the table.
Well, Andrew (whichever), you’ll gather that I’m aiming to be a bit facetious after all such serious talk of trees and stuff…
But to be more serious…..
Briffa’s recent paper states:
prior to the twentieth century, only one period stands out as warm in all regions, a period several decades either side of AD 1000. This is shown prominently in the northwest Eurasian series, but it is clearly punctuated by a brief cold episode, largely related to the short cool interval in the Yamal series (see also Briffa 2000). Hence, there is clear evidence for an interval of widespread enhanced medieval tree growth at high latitudes.
Not happy? Briffa has confirmed the MWP in the region. You want to reject that?
The issue that matters to me is not whether or not the NH MWP was slightly above, below or equivalent to current NH temperatures. I’m more concerned about what the climate will be in 2050, say, than with what it was hereabouts in 1100.
“Not happy? Briffa has confirmed the MWP in the region. You want to reject that?”
Speaking for this Andrew… 😉
Simon,
I don’t WANT to do anything in particular regarding the MWP. I want to scrutinize all the evidence, and if there is not enough to come to a conclusion, then there just isn’t enough and more information is needed and the conclusion will have to wait.
Andrew
Simon says “The issue that matters to me is not whether or not the NH MWP was slightly above, below or equivalent to current NH temperatures. I’m more concerned about what the climate will be in 2050, say, than with what it was hereabouts in 1100”
Well if we can’t explain what happened in the past it is hard to believe our predictions of the future — if there was a non-Anthro warming in the past then there may be another now or in the future and then we should prepare ourselves not by stopping CO2 output but by seawalls, canals, migration etc but if the only explaination is Anthro and hence CO2 then we should be stopping CO2 output. So what happened in 1000 is vital for our choosing a response right now hence the heat in the tree debate.
Well if we can’t explain what happened in the past it is hard to believe our predictions of the future
I don’t think that follows at all, since we have very limited/uncertain data about the past compared to the present.
if there was a non-Anthro warming in the past then there may be another now or in the future
Sure, but if we could take ourselves back to the past we could measure that then just as we can now. Did the sun get hotter? Did volcanic activity drop off? Whatever.
You seem to be suggesting that whatever is uncertain about the past should give us reason to think that the present is a mystery to us.
It is simply not logical to suggest that because we cannot know certainly what forcings prevailed in the past we should therefore presume that our knowledge of forcings in the present is somehow irrelevant. If there is a natural variation to come that we can’t anticipate, then so be it. In the meantime we consider the anthropogenic and natural forcings that know about (hmm – unless you think that GHGs are not forcings? Do you?).
Simon — surely the path is from observation (ie the past) to theory to prediction as a test of theory to reaction. Are you suggesting the past is irrelevent? Are you prepared to ignore any warming last century because it was in the past? It seems to me that the forcing from ghgs is not the question, it is the feedbacks, do they lead to CAGW. If the 1000 years pre-industrialization are temperature flat then last century”s rise (if the past is relevent) is due to anthro but if there are warm periods in the past then maybe natural variation may override the direct forcing of ghgs. And if it got warmer then cooled due to natural processes then there are negative feedbacks that may override the direct forcing. Ignoring the past is not logical either.
Bedtime Story… 😉
This winter, my Dad planted 5 Eastern Redbud trees in my backyard (with my approval). 3 across the end of the yard and two closer to my house near a stump. In the January snow and cold they looked like sad little sticks a child had stuck in the ground for fun. I wasn’t sure that wasn’t all they’d ever be… dead sticks in the ground. But my my, they have grown!
The trees near the stump are in weedy, drier, and harder soil. Well, one of them is gone. Maybe I ran it over with the lawnmower earlier in the year, I don’t recall. 🙁 The survivor near the stump is growing and has healthy-looking leaves but it still smallish vertically. It’s maybe 2 1/2 ft tall.
The other three at the end of the yard have grown much more. They are in the area where more water collects in my yard and gets more sunlight in the evening. They are all at least 4 ft tall and the tallest is almost as tall as me now, 6 ft! They all look nice and healthy.
I guess the point of this story is the one that others have been making on the climate blogs. Each tree has it’s own story. It is obvious that I have significant variations in growth despite the trees being only a few feet apart and them experiencing the same climate.
I hope these trees will see many happy occasions in my yard as they grow (like bbq parties 😉 ), and I hope to keep a record of how they develop. Of course, my little orchard is dedicated to my dad.
Andrew
Jimmny Crickets, that’s what they are always doing. They are research scientists, nothing is ever fully resolved.
The thing that bugs me (sorry Bugs) about all of this is that the arguments about hockey sticks resolve, in part, into whether the term “unprecedented” can be applied to current “warming.”
Suppose the current rate of warming and maybe the magnitude are not unprecedented?
Is it not possible that our “warming” is occurring in a very different (physically reactive or non-reactive) environment from prior warmings?
Is it crazy for me to ask if there are enough data to run the climate models on earlier (assumed to be precedent) eras?
Andrew23,
No, I’m certainly not saying the past is irrelevant. I’m arguing that if we reject whatever palaeo evidence we have because of uncertainties then we’re not left with the means of knowing much at all about it!
What evidence of past global temperatures during the MWP do you think is reliable enough? What is the evidence that has convinced you, and why is that more reliable than Briffa’s reconstructions?
“I’m arguing that if we reject whatever palaeo evidence we have because of uncertainties then we’re not left with the means of knowing much at all about it!”
Simon, I do not think it is wise to pretend we know things for the sake of pretending we know something important, so we can feel better. It is better to deal with the reality that we don’t know and deal with the issue in a realistic way.
Andrew
Lucia, you bring up some good points. I look at it from a different angle however.
That’s probably because they know Prof X to be a serious researcher. The opinions of some are given more weight than those of others because of their track record.
More often, prof X will see some flaws in an otherwise good piece of work, and decides that the flaw is so minor as not to warrant the effort of a formal reply (which indeed takes quite some effort, so is not taken lightly). If (s)he deems the work to be absolute drek, then dependent on the status that the work has or likely will have, some scientists may indeed go through the trouble of writing a formal reply. But only if they feel that the work receives undue visibility and follow-up, and that the implications of the faults are large. See the example of Schwartz’ study on climate sensitivity; I think there are already 3 official replies (see eg http://julesandjames.blogspot.com/2009/09/yet-another-comment-on-schwartz.html).
What you say about the role of blogs is true: They are an informal setting for exchanging ideas. In an very thoughtful comment at Chris Colose’s place, Robert Grumbine calls it “having a beer†(http://chriscolose.wordpress.com/2009/07/02/cycles-projections-and-other-lingo/#comment-963):
Blogs are entirely different from scientific discourse. If a blogger thinks he knows something better than the experts, it’s time to join the experts and tell them (through the scientific channels). It will be an uphill battle, for sure. But if the evidence is strong enough, it will eventually be incorporated into the scientific thinking. Shouting from the sidelines won’t get you the recognition that you feel you deserve from the scientists; then you’re just one of many making a lot of noise and drinking a lot of beer.
“Shouting from the sidelines won’t get you the recognition that you feel you deserve from the scientists”
Who exactly is looking for recognition they feel they deserve from “the scientists”?
Andrew
Bugs:
Briffa work and Yamal proxies have been used in the TAR and 4AR in the chapter on “Understanding and Atrributing Climate Change which is Chapter 9 4AR, IIRC. They were used so that the IPCC could claim that the last 50 years can be attributed to the anthropogenic GHG’s as likely to very likely dependent on the item under construction. The IPCC states this as “evidence” and “robust”. Briffa indicates that he and collegues are developing this “robust evidence” which would indicate that it is not what was claimed in the TAR and 4AR. And you question why I pointed this out? This is not a minor issue unless one justs wants to conclude that the AGW is only about 50% likely. The IPCC did not and claimed they needed this evidence. Go tell them they were wrong. I don’t think you will get far.
“Shouting from the sidelines won’t get you the recognition that you feel you deserve from the scientists”
Uh, are you familiar with the concept of a referee? Those guys who call fouls and penalties aren’t robbers and bandits you know.
Okay, so you used a terrible metaphor. But Jesuit Priest “the recognition that you feel you deserve from the scientists” I mean WOW that’s pretentious.
(By the way, regarding Schwartz’s paper, you seem to be unfamiliar with the concept of a reply to a comment, which Schwartz did, marginally altering his result.)
Simon, I do not think it is wise to pretend we know things for the sake of pretending we know something important, so we can feel better. It is better to deal with the reality that we don’t know and deal with the issue in a realistic way.
C’mon Andrew, you must know I’m not saying that! We take whatever evidence there is and make a judgment on how strong it is. We might decide that’s it’s too weak to be useful, or even that it’s meaningless. What I’d be interested in hearing about are the grounds anyone may have for judging that evidence of a stronger global MWP is stronger than evidence of a weaker one. Now, if all the evidence is too weak then I’d agree with you that we really don’t know, in which case I’d suggest we stop talking about it until we do! There might be fairies at the bottom of my garden controlling the climate, but I have no evidence of them! Hmm, except for those funny rings of mushrooms….
“Now, if all the evidence is too weak then I’d agree with you that we really don’t know, in which case I’d suggest we stop talking about it until we do!”
Simon, I understand except that I think we need to keep talking about stuff so we are constantly re-assesing where we are knowledge-wise. Things are constantly changing. We need to keep communicating… about pretty much everything.
Andrew
Now, if all the evidence is too weak then I’d agree with you that we really don’t know, in which case I’d suggest we stop talking about it until we do!
Tree rings appear to be a pretty weak stand-alone proxy if for no other reason that ring size is not solely a function of temperature.
My impression is that most but not all proxy studies of all kinds confirm the existence of a pronounced, global MWP (see, for example this collection.
As others have noted, the real flaw in the “hockey stick” genre of reconstructions is the methodological need to flatted the blade by finding ways to weight preferred data sets to overwhelm the less desirable results. When you look at graphs of the the individual studies (for example, http://www.climateaudit.org/?p=3512) they are noisy but tend to be higher in the MWP. However, when Prof. Mann et al get finished with them, the result is always a hockey stick.
The evidence for the existence of a MWP seems reasonably strong. The evidence is also also pretty strong that the “hockey stick” methodologies are suspect or, more charitably put, less robust and far more subjectively crafted than advertised.
George,
My impression is that most but not all proxy studies of all kinds confirm the existence of a pronounced, global MWP (see, for example this collection.
Thanks for the link to CO2 Science. I’ll go through the first few with some comments –
http://www.co2science.org/data/mwp/studies/l1_coldaircave.php
This marks an MWP peak at about 900AD and asserts that “Peak warmth of the Medieval Warm Period was as much as 2.5°C warmer than the Current Warm Period.” However, you will note a later peak at c1500AD indicating 3C+ warmer, well into the Little Ice Age. Hmm!
http://www.co2science.org/data/mwp/studies/l1_makapansgat.php
The same location and a stalagmite again. The marking of the ‘MWP’ now runs from 1000 to 1300AD peaking in 1250 and 1300. Apart from the indicated MWP having moved a few hundred years, try comparing this with the first one to see if you think there’s any correlation.
http://www.co2science.org/data/mwp/studies/l2_morocco.php
This is tree rings, which you’ve said you think are weak proxies. You might note that it references a study of drought response!
I’ll stop there. Some of the studies may well confirm one another’s indication of the timing of an MWP, but very many of them appear to contradict one another. There’s nothing intrinsically wrong with that, of course, but this is why we need multi-proxy studies (or at least multi-location studies of the same proxy type) to advance our understanding.
You then say, referring to the Mann et al 2008 study:
When you look at graphs of the the individual studies (for example, http://www.climateaudit.org/?p=3512) they are noisy but tend to be higher in the MWP.
You seem to be in disagreement with Steve McIntyre in the article you link to, who says:
One’s first impression is that there isn’t a common signal in this data.
It’s clear that you are suspicious of the methodolgy of Mann and others. What is not clear is whether you have an equivalently sceptical approach to the ‘CO2 Science’ site (particularly to their own ‘descriptions’ of the papers).
I seem to remember reading the Soon and Balliunas paper a few years ago which tried to show a global MWP. From my memory (I suppose I could get the paper out!) all they showed was that at various times around 1000 AD there were 50 year periods with warm tempertaures and/or increased precipitation. This lead them to posit a global MWP. Didn’t seem to me to be very convincing. The MWP also says nothing to me about present attribution.
Put simply, we know there is a Greenhouse effect; we know that C02 is a GHG; we know its atmospheric concentration has increased; we have very strong evidence to believe that this increase is anthropogenic; we would expect this to induce warming (which seems to have occurred) and we would expect that this will continue and be significant (define as you want to) because we know sensitivity (within bounds). We also might expect some impacts and that these would likely be negative for human an ecosystems.
Of course, we can argue about the details until the cows come home (like Steve M is good at), but this doesn’ change the bigger picture (and my few dealings with Steve M suggests that he thinks so too).
san quintin (Comment#21279),
“Of course, we can argue about the details until the cows come home (like Steve M is good at), but this doesn’ change the bigger picture..”
Sure it does; the devil is always in the details. Of course increases in greenhouse gases must warm the planet’s surface, but it matters a LOT if the warming is 1.5C for a doubling of CO2 or if it is 4.5C. The key issue is an appropriate (political/taxation/public control) response to increases in CO2, and what is appropriate depends completely on how much warming will take place. To over-hype the potential warming (as I honestly think many do) so as to justify massive changes at enormous cost is just as irresponsible as to claim there is no warming from GHGs. Both avoid the difficult balance that needs to be struck between costs and benefits.
Simon — some MWP refs for you — when (if) you convince each author they are wrong come back — if you just what to throw tomatoes at a distance … well I hope you have fun:
1. Jones, Terry L.; Schwitalla, Al (2008). “Archaeological perspectives on the effects of medieval drought in prehistoric California”. Quaternary International 188 (1): 41–58. doi:10.1016/j.quaint.2007.07.007.
2. Keigwin, Lloyd D. (29 November 1996). “The Little Ice Age and Medieval Warm Period in the Sargasso Sea”. Science 274 (5292): 1503–1508. doi:10.1126/science.274.5292.1503.
3. Hu FS, Ito E, Brown TA, Curry BB, Engstrom DR (2001). “Pronounced climatic variations in Alaska during the last two millennia”. PNAS 98 (19): 10552–10556. doi:10.1073/pnas.181333798. PMID 11517320.
4. Bradley, Raymond S. Climate System Research Center. “Climate of the Last Millennium.” 2003. February 23, 2007. [1]; E.L. Ladurie, Times of Feast, Times of Famine: a History of Climate Since the Year 1000 (0(Barbara Bray, tr.) (New York: Doubleday)1971.
5. Raymond S. Bradley, Malcolm K. Hughes, Henry F. Diaz (2003). “Climate in Medieval Time” (PDF). Science 302 (5644): 404–405. doi:10.1126/science.1090372. PMID 14563996. http://www.geo.umass.edu/faculty/bradley/bradley2003d.pdf. (links to pdf file)
6. How Warm Was the Medieval Warm Period? Thomas J. Crowley and Thomas S. Lowery Ambio, Vol. 29, No. 1 (Feb., 2000), pp. 51-54
7. Keigwin, Lloyd D. (29 November 1996). “The Little Ice Age and Medieval Warm Period in the Sargasso Sea”. Science 274 (5292): 1503–1508. doi:10.1126/science.274.5292.1503.
8. “The History of English Wine: Domesday & Middle Ages”. http://www.english-wine.com/history.html#domesday. Retrieved 2006-05-04.
9. Jones, Gregory (August 2004). “Making Wine in a Changing Climate”. Geotimes. http://www.agiweb.org/geotimes/aug04/feature_wineclime.html. Retrieved 2007-09-04.
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15. Cobb, Kim M.; Chris Charles, Hai Cheng, R. Lawrence Edwards (July 8, 2003). “The Medieval Cool Period And The Little Warm Age In The Central Tropical Pacific? Fossil Coral Climate Records Of The Last Millennium”. The Climate of the Holocene (ICCI) 2003. http://www.pac.ne.jp/IUGG2003/EN/program.asp?session_id=MC12&program_id=022025-1. Retrieved 2006-05-04.
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18. Wilson, A.T., Hendy, C.H. and Reynolds, C.P. 1979. Short-term climate change and New Zealand temperatures during the last millennium. Nature 279: 315-317.
Andrew, Not sure what point you’re trying to make, but if it is that MWP was warmer or as warm as now, at least one (and probably more) of your ref’s don’t support that contention.
From ref 5: “The balance of evidence does not point
to a High Medieval period that was as
warm as or warmer than the late 20th century.”
And about those English vineyards, see eg http://www.realclimate.org/index.php/archives/2006/07/medieval-warmth-and-english-wine/
Hi SteveF
But we know that climate sensitivity can’t be low (the palaeo record shows it must be around 3 C at least) and this means that continued emissions will produce high levels of warming. Doubling C02 can’t produce only 1.5C warming. So likely impacts will be severe and therefore we need to reduce emissions radically.
AndrewK, AndrewF,
I was referring to the fact that many people from outside of the science proclaim loudly that the science is wrong.
If you want such a strong claim to be taken seriously by anyone (besides your fellow shouters and ideological bedfellows), you have to play the game. The science game. Otherwise you’re just one more of those people shouting things like “The earth is flat, hollow, expanding, 6000 years old, and so on” to quote Robert Grumbine.
Andrew, that’s a good list (though you put one of them in twice!). There’s a few more at
http://globalwarmingquestions.googlepages.com/mwp
concentrating on places outside Europe.
Bart, you should read the primary source, Selley’s book on the Winelands of Britain, not the distorted spin put on it by Gavin Schmidt.
PaulM,
Show me where Gavin’s analysis of the English wine tale is so wrong as to render his whole argument invalid, and I will concede.
A quick look at the first pdf linked in that list showed the conclusion I quoted. A list looks impressive, but if it doesn’t support your contention, it is just smoke and mirrors.
Andrew Kennet,
Thank you for your references.
when (if) you convince each author they are wrong come back
I have no expectation at all of considering any such authors to be ‘wrong’ (whatever you mean by that). You don’t say what you think your evidence amounts to in terms of the temperature of a global simultaneous MWP, so I can’t say whether I think you wrong or not.
Before commenting on your list, I need to ask what were your critieria for picking out these particular studies? There are plenty of accusations around of cherry-picking results that suit your prejudices, so can you assure us that you have not done this? I can see no obvious examples of studies which would count as evidence against your view, even though you must know there are plenty to choose from, so I do suspect that you may be doing exactly what some people have falsely accused Briffa of doing.
I’ll spend the time responding to your list in more detail once I know your selection criteria. For now, I’ll state the obvious points that your list is overwhelmingly one of NH locations and you give no indication yourself of the extent to which they do or do not suggest correlated warm periods.
It is not in dispute by me that there was an MWP, but the question of whether such a period was globally simultaneous is another matter, as is the indicative global average temperature during such a period. You must surely be aware that when we compare with present temperatures we do not compare with regions showing the highest anomalies, but with the global average.
I look forward to you clarifying your selection criteria.
Hmm, I’ve just started to work through the papers on Andrew’s list….
1. Jones, Terry L.; Schwitalla, Al (2008). “Archaeological perspectives on the effects of medieval drought in prehistoric Californiaâ€. Quaternary International 188 (1): 41–58. doi:10.1016/j.quaint.2007.07.007.
Oh dear. Andrew, this is not a paper presenting any form of temperature reconstruction. Go look.
2. Keigwin, Lloyd D. (29 November 1996). “The Little Ice Age and Medieval Warm Period in the Sargasso Seaâ€. Science 274 (5292): 1503–1508. doi:10.1126/science.274.5292.1503.
Yup. LLoyd finds the Sargasso Sea indicated as being warmer in c1000AD than today. Well done!
3. Hu FS, Ito E, Brown TA, Curry BB, Engstrom DR (2001). “Pronounced climatic variations in Alaska during the last two millenniaâ€. PNAS 98 (19): 10552–10556. doi:10.1073/pnas.181333798. PMID 11517320.
Woops. The paper charts the Alaskan lake as being warmer today than at any time during the MWP. Sorry.
4. Bradley, Raymond S. Climate System Research Center. “Climate of the Last Millennium.†2003. February 23, 2007. [1]; E.L. Ladurie, Times of Feast, Times of Famine: a History of Climate Since the Year 1000 (0(Barbara Bray, tr.) (New York: Doubleday)1971.
Oh dear. Bradley finds:-
One thing that all reconstructions shown in Figure
6.6 clearly agree on is that northern hemisphere
mean temperature in the 20th century is unique, both
in its overall average and in the rate of temperature
increase. In particular the 1990s were exceptionally
warm — probably the warmest decade for at least
1000 years (even taking the estimated uncertainties
of earlier years into account).
I think I’ll give up at that point.
Are you claiming to have read these papers, Andrew? If so, why on earth are you presenting this list as evidence of whatever case you wish to put?
I can’t resist another one –
6. How Warm Was the Medieval Warm Period? Thomas J. Crowley and Thomas S. Lowery Ambio, Vol. 29, No. 1 (Feb., 2000), pp. 51-54
maximum Medieval warmth was restricted to two-three 20–30 year intervals, with composite values during these times being only comparable to the mid-20 th century warm time interval. Failure to substantiate hemispheric warmth greater than the present consistently occurs in composites because there are significant offsets in timing of warmth in different regions; ignoring these offsets can lead to serious errors concerning inferences about the magnitude of Medieval warmth and its relevance to interpretation of late 20 th century warming.
Simon Evans:
1) Finding conflicting studies the the CO2 Science site may be jarring to people who are used to the appearance of doctrinal purity.
I generally trust the CO2 Science compendium precisely because they do not suppress, filter out, or weigh the numbers. The composite is messy. They include results that do not confirm their point of view.
So congratulations for finding some contrary results among what is offered. No go do a similar search on Real Climate or Tamino to see if anomalous results are acknowledged as candidly.
2) My point about the graphs posted at Climate Audit (there is also a collection of graphs of the individual studies in Mann’s more recent multi-proxy hockey stick but I don’t have the link at the moment) is that the majority of those studies show a MWP. McIntyre is obviously right that they do not all show the same signal–and the contradictory nature of tree ring data seems rather characteristic for the reasons I suggested in my previous post.
In any event, to conclude that such data collectively yields a hockey stick is utterly contrived.
3) The hockey stick is sold to the general public as if the numbers simply present a clear pattern. When McIntyre et al demonstrate that is not the case, the fallback position is that precisely because the data is so contradictory, only the enlightened can see the true pattern using methods that the uninitiated are not entitled to examine.
If the methods are discovered and found wanting, it is irrelevant because the enlightened already just know the hockey stick has been “confirmed” by other studies.
If it turns out the majority of proxy studies do not confirm that, then such a finding is forever suspect unless and until the enlightened choose to perform a similar review.
The issue deserves a response more substantive that the clubby narcissism that seems to be the habit of Team defenders.
George Tobin,
I generally trust the CO2 Science compendium precisely because they do not suppress, filter out, or weigh the numbers. The composite is messy. They include results that do not confirm their point of view.
On the contrary, they assert that the results confirm their view, even though that is not true! Furthermore, it is nonsense to suggest that they do not ‘filter out’. You must surely be aware that they have selected only proxy data that suggests a pronounced warm period at some time or another which they then label the MWP? Can you point to one example of a proxy they reference where they do not assert an MWP peak? Do you really need me to refer you to proxies which show no such peak, even give or take the couple of hundred years that they allow themselves? Your assertion is demonstrably untrue.
As for Mann 2008, McIntyre said that at first glance they didn’t show a common signal. Of course they don’t show the same signal!
And further, George –
My point about the graphs posted at Climate Audit (there is also a collection of graphs of the individual studies in Mann’s more recent multi-proxy hockey stick but I don’t have the link at the moment) is that the majority of those studies show a MWP.
The result of Mann et al 2008 shows an MWP, for goodness’ sake!
“If you want such a strong claim to be taken seriously by anyone (besides your fellow shouters and ideological bedfellows), you have to play the game.”
You don’t have to. All you have to do is show your evidence and describe your thought processes to a reasonable person. That person (if open minded) will take your presentation seriously.
You are talking about playing some kind of game to appease a certain group of people. I think that’s childish.
Andrew
san quintin (Comment#21313)
But we know that climate sensitivity can’t be low (the palaeo record shows it must be around 3 C at least) and this means that continued emissions will produce high levels of warming. Doubling C02 can’t produce only 1.5C warming. So likely impacts will be severe and therefore we need to reduce emissions radically.
Actually, the paleoclimate records show that the CO2 sensitivity is only 1.5C per doubling. 3.0C per doubling is consistently too high throughout just about the entire record. I have all the data and will be putting it up in a nice useable form soon for those that want to check for themselves.
I was under the impression that Science should be a perpetual trial of new and old ideas. We need a free idea market for that to happen. Why would we let a group of elitists suppress what’s vital to Science? Makes ya wonder, don’t it? 😉
Andrew
Simon Evans:
Can you point to one example of a proxy they reference where they do not assert an MWP peak?
Ok. Well, there is this one. which states without snark or spin: ” For the Huascaran Glacier (9.11°S, 77.62°W), this work suggests that the MWP was not as warm as the CWP.”
Though is obviously true that their mission is to demonstrate the existence of a global MWP, the Idso brothers do provide descriptions of studies that do not confirm their view that the MWP was as warm or warmer than the present era see this or this one, or this as well as an overall counts of studies that confirm or deny.
Now it’s your turn to find equal candor and snark-free open-minded inclusion of contrary findings on Real Climate or Tamino.
You complain of a selection process at the CO2 Science site so you must be especially outraged by the incredible massage job in Mann 2008 which is apparent when you can see the graphs of the individual data sets that supposedly comprise Hockey Stick II.
You can make a fair criticism about selection of date ranges, interpretation of some studies in the summaries etc in the CO2 Science list. But at least it’s all out front. I don’t have to rely on references to unavailable data sets or absurdly complex algorithms whose purpose appears to be to weight bristlecone pines or selected Finnish lake bottoms.
san quintin (Comment#21313),
“But we know that climate sensitivity can’t be low (the palaeo record shows it must be around 3 C at least) and this means that continued emissions will produce high levels of warming. ”
Do we? Paleo results are not so simple to interpret, and depend on a set of assumptions which may not be correct. If climate scientists can’t define the current (negative) forcing due to atmospheric aerosols to any better than +/- 80%, how can paleo studies to estimate climate sensitivity be so certain?
What we really do know is 1) that climate models using high climate sensitivity (similar to the paleo values) consistently predict more warming than has been observed, 2) that ocean heat accumulation since 2003 is near zero (in clear conflict with the climate models), 3) that high sensitivity requires long ocean lag periods which are not evident in the ocean heat data, and 4) that a wide range of climate sensitivities is completely consistent with the instrument temperature record, depending on what values for aerosol forcing and ocean lag are assumed.
It is clear that GHGs must warm the Earth’s surface, but the magnitude of the warming matters a lot in terms of what costs can be justified to control emissions of CO2. IMO, we need to be very sure of the magnitude of warming, and pretty sure of its consequences, before obliging most of mankind to large economic sacrifices to avoid/reduce that warming.
Hi Bill Illis. I’d be intrigued to see your explanation of the palaeo record with low sensitivity. I hope you publish it in the mainstream scientific literature, because it will overturn much of what we thought we knew.
SteveF. I think you must be confusing equilibrium with transient sensitivity….there’s quite a difference!