Chris Mooney is a freelance writer and the author of two books, 
Is anyone else as sick as I am of repeated attacks on the "hockey stick" reconstruction of past temperatures? Joe Barton and cronies are at it again. Just when one would have hoped that the National Academy of Sciences report on this topic would provide some modicum of closure, the "skeptics" have derived yet another seeming line of attack.
As for myself, I am beyond bored with the whole thing. I'm reaching the point of despair. Listen, people: This is an argument over a study that is now some eight years old. Eight years! You would think there is nothing new under the sun in climate science.
So let us recite, once again, for those who still don't get it: One study never definitively proves anything in science. Any single study can be attacked and criticized. Any individual piece of work will have its gaps, shortcomings, and associated uncertainties. As for those who show no appreciation of this fact, who obsessively beat up on a single study for political reasons: By this behavior, they simply show that they approach scientific information as lawyerly debunkers, rather than by trying to accurately grasp the big picture.
And make no mistake: Despite the new fireworks, that big picture remains unaltered. Whether the "hockey stick" is right, wrong, or irrelevant, the underlying message on global warming is that we're causing it. Period. End of story.
Comments
It's just like hearing Creationist arguments against evolution citing the second law of thermondynamics or tornadoes in junkyards--you can't kill the arguments because, like zombies, they are the Undead (and just as thoughtful).
Posted by: mark | July 17, 2006 8:25 AM
Here's a link to the full WSJ editorial.
Posted by: James Hrynyshyn | July 17, 2006 9:41 AM
And after all is said and done, you offer nothing more than your vehement statement. I would ask the previous commenter, which side is the creationists? Nether side in the global warming debate offers any real science. Despite your proclamations to the contrary, the debate is still on, and it is people like you that try to stifle legitimate avenues of inquiry that are the real torture.
I can understand your feelings about the hockey stick, perhaps it is old. But the NAS report, even if taken at face value, actually weakens the argument that global warming is caused by humans. The NAS report clearly shows that the global temperature has historically fluctuated more than enough to account for the current warming trends, even before the increase of CO2 due to human influence.
All the NAS report has done is shown that the current global temperature is higher than a time period that has historically been known by climate scientists as "The Little Ice Age". I somehow do not find that very compelling
Posted by: Brian Utterback | July 17, 2006 10:37 AM
...the underlying message on global warming is that we're causing it. Period. End of story.
The latest arguments I've been hearing concern themselves with whether we've caused all the warming so far, or just some of it. And if it's not all ours, then chances are it won't be that bad.
For instance, this is from the National Review:
http://article.nationalreview.com/?q=NGIzNWNjYmVhYjE2M2RmNDM2OGM0ODRjN2QwNjE1ODM
The next stage of the argument concerns how "Al Gore and his climate scientist allies" (as they like to frame it) get some things right, but are alarmist on other things. And they use Mann and his study as an object lesson on alarmism. They're saying the hockey stick that everyone's been using in presentations over the years is not so dramatic, not based on "sound science," says something about the type of science "alarmists" rely on, yadda yadda yadda.
Anyway, those are the arguments I've been hearing.
Posted by: Jon Winsor | July 17, 2006 10:45 AM
Thanks, James.
In addition to Chris' comments about abuse of science by using single studies to support an agenda (on either side), there is also the issue about selective use of statistics.
I would argue that including anything before 1800 (i.e. most of the Little Ice Age [ http://www.scienceshelf.com/LittleIceAge.htm ] and all of the Medieval Warming Period) in that graph adds data that is irrelevant to the question at hand, namely the effect of large-scale burning of fossil fuels on the climate.
What's left is still complicated enough, since coal-burning added plenty of soot, acid, and gases other than CO2 to the atmosphere. Of course, the normal climate variation has to be considered in any interpretation. That's why the hockey stick is not only dramatic but also demands skeptical aanalysis.
The editorial writer makes a specious argument, namely that the hockey-stick graph is the only data around which the consensus has formed. It was, no doubt, the catalyst for a lot of consensus, but normal scientific skepticism put the brakes on any bandwagon effect.
Of course, the skepticism that keeps a bandwagon from rolling can be used as evidence that scientists don't agree about the conclusion.
Science abusers use both arguments at the same time. We science appreciators need to point that out when we see it. Perhaps we need to explain the difference between the excitement over a new discovery and the consensus that emerges from challenging the interpretation of that discovery.
Posted by: Fred Bortz | July 17, 2006 11:49 AM
...the NAS report, even if taken at face value, actually weakens the argument that global warming is caused by humans.
I'd encourage you to look at the Realclimate post on this subject:
http://www.realclimate.org/index.php/archives/2006/06/national-academies-synthesis-report/
And there are a number of conclusive studies that link the "signature" of CO2 with warming:
http://www.heatisonline.org/contentserver/objecthandlers/index.cfm?id=3458&method=full
The NAS report clearly shows that the global temperature has historically fluctuated more than enough to account for the current warming trends, even before the increase of CO2 due to human influence.
Historically, CO2 and warming levels have risen and fell together:
http://www.grida.no/climate/ipcc_tar/wg1/fig2-22.htm
Posted by: Jon Winsor | July 17, 2006 12:07 PM
The NAS report clearly shows that the global temperature has historically fluctuated more than enough to account for the current warming trends.
It shows no such thing. Insofar as it changes the previous results, it says that it is less certain about previous trends - which leaves space for them to be either larger or smaller than previously though. It certainly doesn't say that they are as large as current trends.
Posted by: William Connolley | July 17, 2006 1:35 PM
Interesting. I've followed the creation-evolution debate (a lot) and the global warming debate (a little) and I constantly see the hockey stick waved about. Whereas creationists' claims are usually easily refuted, I have less luck making sense of the climate debate. This of course may be because I'm not studying climate science, but also because those actively trying to deny human-induced global warming seem to be more in touch with the actual science (rather than religious dogma). What's a good web-source for summaries of the points-counterpoints?
Posted by: Phobos | July 17, 2006 2:20 PM
What's a good web-source for summaries of the points-counterpoints?
I would say that from a lay perspective a good summary of the skeptics' arguments and their counterpoints would be this blog:
http://illconsidered.blogspot.com/2006/02/how-to-talk-to-global-warming-sceptic.html
Illconsidered points to other sites, such as Realclimate.org, which discusses specific topics in more technical detail.
Although it's true that creationists and climate change denialists are different, there's some degree of overlap as well. I liked Desmogblog's breakdown of the ideological spectrum after they attended the Skeptics' Society conference:
http://www.desmogblog.com/skeptics-conference-an-ideological-battleground
Also, the Washington Post did a good job describing the skeptic community with this story:
http://www.washingtonpost.com/wp-dyn/content/article/2006/05/23/AR2006052301305_pf.html
Posted by: Jon Winsor | July 17, 2006 4:43 PM
I don't think this is an appropriate response to the Wegman report. Wegman, Scott, and Said have confirmed the criticisms of McIntyre and McKitrick (and in particular that the hockey stick is an artifact of the decentering methodology; they get a similar pattern by using "red noise" as data), and further argued that there is a lack of independence of data sets in paleoclimatology and isolation from appropriate review of mathematical methods (i.e., by statisticians).
The critique of Wegman et al. merits some housecleaning--bringing statistics expertise into the field of paleoclimatology--not dismissal, in my opinion.
The full Wegman report (91 pp) is here:
http://energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf
"Whether the "hockey stick" is right, wrong, or irrelevant, the underlying message on global warming is that we're causing it. Period. End of story."
But possibly 10-30% less of it than we've thought we were causing:
http://www.dukenews.duke.edu/2005/09/sunwarm.html
Posted by: Jim Lippard | July 17, 2006 6:00 PM
But that's Scafetta and West, old news already scrutinized, nothing new there.
For one example (Google is your friend):
http://www.realclimate.org/index.php?p=192#comment-4810
Posted by: hank | July 17, 2006 6:58 PM
Is anyone else as sick as I am of repeated attacks on the "hockey stick" reconstruction of past temperatures?
The rubes still obsessing over the hockey stick don't realize the puck has been dropped, we're three quarters of the way through the first period and the score is already 8-0 in our favour.
Posted by: Robert McClelland | July 17, 2006 7:05 PM
"The critique of Wegman et al. merits some housecleaning--bringing statistics expertise into the field of paleoclimatology--not dismissal, in my opinion."
I agree. The best way to deal with problems in science is to address them -- and address them in the standard scientific way: by publishing papers in scientific journals.
The latest report is no exception to this rule. It should be submitted for publication in a journal which will mean it gets reviewed by other statisticians for possible errors.
If it passes that test, then Mann and possibly others will be forced to address the problems and resubmit their revised paper or retract their findings. That's how science works -- or at least how it is supposed to work
Posted by: Dark Tent | July 17, 2006 7:29 PM
In related news, the entire field of electronics has been thrown into disarray after errors were discovered in Millikan's research, on which foundation all subsequent work in electronics relies for its validity.
http://www.sigmaxi.org/meetings/archive/forum.2000.millikan.shtml
"This may bring down the entire edifice of scientific rationality. Wouldn't that be like, magical?" typed one weblogger, just before his computer lost its phlogiston and the smoke leaked out.
Posted by: hank | July 17, 2006 9:30 PM
But wait!
The measurements' "... accuracy was not severely affected by Millikan's choice ...."
http://www1.umn.edu/ships/ethics/millikan.htm
"At first blush, this outrageous violation of scientific integrity would seem to discredit Millikan's findings. Even if one assumes that standards of reporting data earlier in the century were less rigorous, Millikan clearly misrepresented the extent of his data. One may caution students, however, that we may not want to conclude that therefore there was no good, "scientific" basis for his selective use of data.....
"Physicist-philosopher Allan Franklin has addressed the problem by using Millikan's original data to recalculate the value of e. Even when one uses various constellations of the raw data, Millikan's results do not change substantially. That is, their accuracy was not severely affected by Millikan's choice of only a subset of the observations. Millikan's selectivity, at most, gave a false impression of the variation in values or the range of "error" in the data and, therefore, of the statistical precision of the computed value.
"In fact, Franklin notes, Millikan threw out data that was "favorable" as well as "unfavorable" to his expectations. Clearly, Millikan's results were over-determined. That is, he had more data than he needed to be confident about his value for the electron's charge. Here, the redundancy of data was an implicit method for safeguarding against error. Thus, what appears as fraud from one perspective becomes, from an experimental perspective, a pattern of good technique..."
Posted by: hank | July 17, 2006 9:34 PM
As usual, it's not the crime but the subsequent cover-up that gives a scandal legs.
If Mann & company had quickly and fully acknowledged their mistakes and made their data and methods available to other scientists for review, the problem would have disappeared in no time. Certainly less than eight years. The real problem here isn't that Mann blew it but that trying to figure out /how/ he blew it took so much time and effort and slogging through mud being thrown at McIntyre and McKitrick.
Federally funded science shouldn't mean giving money to researchers who collect data, massage it in unknown ways and just say "trust us, it's right" when their conclusions are questioned.
Posted by: Glen Raphael | July 17, 2006 11:52 PM
The panel said the results don't change significantly when the improved methods are used, and they said they're worried about the rate of warming (even though they were not asked to comment on the latter point).
Does that worry you at all?
Posted by: Hank Roberts | July 18, 2006 11:04 AM
"All the NAS report has done is shown that the current global temperature is higher than a time period that has historically been known by climate scientists as "The Little Ice Age". I somehow do not find that very compelling"
This is what the NAS report acutally said - "The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on icecaps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is nprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward."
Posted by: Patrick Kennedy | July 18, 2006 11:40 AM
We can all pick our favourite quotes such as page 110 of the NAS report
"Largescale temperature reconstructions should always be viewed as having a "murky" early period and a later period of relative clarity. The boundary between murkiness and clarity is not precise but is nominally around A.D. 1600. Second, the finite length (about 150 years) of the instrumental temperature record available for calibration of large-scale temperature estimates places limits on efforts to demonstrate the accuracy of temperature reconstructions."
Their criticisms of bristlecones, non-centred PCA and lack of disclosure are backed up by Wegman and I find it hard to see how this will not eventually be accepted as fact and another name will eventually join that of Millikan.
Posted by: David H | July 18, 2006 12:50 PM
Interestingly, both sides in the debate over the Mann paper claim vindication from the NAS report.
At least part of the problem (as I see it) is that the NAS scientists who wrote the report did not properly define some of their critical terms.
There is one term in particular ( "plausible" ) that stands out from all others: .
Here's the sentence from the NAS report about the Mann paper where they used the term:
"Based on the analyses presented in the original papers by Mann et al.and this newer supporting evidence,the committee finds it plausible [emphasis added] that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium."
They used the term without defining it and this has led to needless ambiguity which has diluted the ultimate value of the report as a guide for public policy.
Then again, the opposing "camps" in this case are so thoroughly entrenched that it might not have made any difference whatsoever what the NAS said.
The latter point is one more argument for moving beyond the Mann papers and focusing on more recent research.
While I think that Mann et al should address any problems with their original paper, the "debate" about the Mann paper should not be the central focus of climate science.
A great deal of independent research has been done in recent years that is relevant to the subject of global warming and to fous on a single paper does not do proper justice to either the science or the public policy.
Posted by: Dark Tent | July 18, 2006 1:16 PM
Science doesn't provide absolute certainty or uncontrovertible proof.
It never will. Science isn't based on a foundation of perfect work.
Science starts, in any area, with early studies, flawed as they invariably have been.
You want to group Mann with Millikan?
Chuckle.
Posted by: hank | July 18, 2006 1:35 PM
The NAS report was more an exercise in the politics of science than a scientific review of Mann et al. As pointed out by David H. the report tries to spare Mann and the current "consensus" while also pointing out the obvious deficiencies in the study and the large uncertainties in attempting to correlate paleo-climate temperature "proxies" with the problematic empirical temperature measurements of the last 150 years.
It is certainly not a vindication of Mann or the "consensus" view that the recent warming trend is an accepted fact and indicative of a dangerous and man made phenomenon.
Posted by: Lance Harting | July 18, 2006 1:52 PM
On the Milikan issue, as part of an undergraduate lab course we were assigned the task of repeating his experiment. Man, talk about the most tedious and challenging exercise in futility! I damn near went blind and insane trying to record the motions of those tiny oil droplets.
Our final results had a calculated error that was about five times our measurement. I chalked up our less than stellar results to our relatively hastily prepared experimental set up and the gross indifference of my equally innept lab partners. But it did make me question how anyone could get the results that Milikan obtained.
I knew that bastard was cheating!
Posted by: Lance Harting | July 18, 2006 2:08 PM
Brian Utterback: "And after all is said and done, you offer nothing more than your vehement statement." (snip)
Wait for it, wait for it....
"Nether side in the global warming debate offers any real science. Despite your proclamations to the contrary, the debate is still on, and it is people like you that try to stifle legitimate avenues of inquiry that are the real torture."
And it's a *high* pop Freudian Projection, right into center field.
Posted by: Barry | July 18, 2006 5:36 PM
Thanks Chris, I share in your frustration. We have spent a lot of time pointing out the idealogues who continue to cherry pick the NAS report to meet their own forgone conclusions.
As for one side receiving vindication from the NAS report, I would say there is no vindication b/c the report says nothing more than what the IPCC claimed so long ago.
As for "picking quotes" to meet our own ends, there are quotes and there are conclusions in the NAS report and the conclusions are very clear -- it's hotter now than it has been in the past 1,000 and multiple lines of evidence since Mann have shown this. Oh, and humans are too blame.
Posted by: Kevin Grandia | July 18, 2006 5:44 PM
Chris, think of it this way - for the past 150 years, evolution has been supported by wave after wave of biological discovery, and in turn has supported biological discovery, turning biology into a science, as opposed to collecting and naming things. However, the religious right, along with various fellow travelers, have managed to wage a pretty good delaying actions (considering that *all* of the science is against them, and they have to rely on lies, BS, poor logic and junk science). And this is all with the power of concentrated wealth neutral, or favoring science.
Therefore, considering that success, it's not surprising that the global-warming deniers will use the same tactics. And they have the added edge that concentrated wealth is generally still against the science.
Posted by: Barry | July 18, 2006 6:12 PM
To claim that anthropogenic climate change theory is on equal footing with the theory of evolution demonstrates a complete lack of understanding of the current state of one or both theories.
These kinds of statements are often followed by allusions to cigarette company shills and holocaust "deniers". They fall into the category of smear tactics. Some environmental NGOs and their attendant media outlets are pushing an aggressive "don't acknowledge the deniers" approach. It may be a good political strategy. It certainly isn't a valid scientific response.
Posted by: Lance Harting | July 18, 2006 11:12 PM
Honest curiosity -- what science have the deniers published lately? M&M is the only one I've heard mentioned in discussions (Wegman's not published), but I don't generally go looking for these things.
If they're not publishing results supporting their views, I don't see how there can even be a scientific response, or why we should even seriously consider their position.
Though I agree that AGW is certainly less solid than evolution. Evolutionary theory has had a wee bit more time to mature than the theory underlying AGW.
Posted by: Davis | July 18, 2006 11:48 PM
For more background info on the science behing global warming, see The Discovery of Global Warming, by Spencer Wart. You can read it online (http://www.aip.org/history/climate/index.html) or order the book.
I recommend reading the section on the discovery of the carbon dioxide greenhouse effect first: http://www.aip.org/history/climate/co2.htm
Posted by: Jackie at Element List | July 18, 2006 11:54 PM
The Discovery of Global Warming is both a book and a wonderful comprehensive website.
The author's name is Spencer Weart.
Posted by: Hank Roberts | July 19, 2006 11:02 AM
Oh, Lordy Lord Lord Lord ..
Wegman, at the hearings: "Carbon dioxide is heavier than air. I don't know where it sits with respect to the atmospheric profile."
Posted by: hank | July 19, 2006 1:26 PM
Hearings: Rep. Stearns (Florida) has people looking at a picture in _Inconvenient_Truth_ showing a temperature change over time. The temperature data, another representative points out, is identified in the text as from the IPCC and based on Lonnie Thompson's borehole measurements.
Stearns is saying that all these similar charts come from the IPCC, and the IPCC comes from Mann's chart, so people are being confused about the origin of the picture.
He thinks that anything that looks like a recent increase has to be based on Mann's work -- or he's trying to put in the record that misinterpretation.
These points must be scripted. Nobody can be this obtuse extemporaneously.
Posted by: hank | July 19, 2006 1:45 PM
Hearings:
Barton on the purpose of the hearings said that if attempts are made to control CO2 emissions "there won't be any coal fired power plants ...."
---
North: "by the end of this century ... if we do nothing .... it might be 3 degreed F, it might be 8 ....even 3 degrees is not as benign as you might think ...."
...
Barton: "representing a coal area of the country, I have a lot of constituents coming up to me ... there's more carbon dioxide caused by natural processes ..."
North: "the problem with this is the time scale, the time constant as we say is quite long, it takes a couple of hundred years ... so if you dump in carbon dioxide ... we're pouring it in faster than the system can dispose of it."
Posted by: hank | July 19, 2006 2:24 PM
Hearings:
Rep. from a timber state (can't read the screen) says he's also on the committee that handles Forestry. He just got North to agree that cutting down big old trees and planting little new ones is a good way to increase absorbtion of CO2. North at least said it was way outside his area but "intuitively it's true."
Good way to avoid looking at the real studies on old growth and old soils.
Posted by: hank | July 19, 2006 2:33 PM
Hearings:
North gave a definition of "plausible" -- the word that had raised questions.
He said they used that word to describe a question on which there are many studies supporting one conclusion and none that contradicted it.
Posted by: hank | July 19, 2006 4:12 PM
Hank posted above: Wegman, at the hearings: "Carbon dioxide is heavier than air. I don't know where it sits with respect to the atmospheric profile."
I'm no expert on the atmospehere, but it would make some sense that CO2 sits at the bottom of the atmosphere, next to the ground, wouldn't it?
I mean, isn't that why young trees (needing CO2 for photosynthesis) grow so much faster than old ones? (because they are closer to the ground where all the CO2 is. H2O too.)
Isn't that also why prairie dogs come out of their holes periodically, for a breath of oxygen?
It seems that all the CO2 (being heavier than air) would settle into the holes and if the prairie dogs did not come out now and again, they would simply die of suffocation. I beleive that is also why they actually have to (not just come out), but also sit up on their hind legs, to get above the CO2 layer, which is right next to the ground.
Posted by: George | July 19, 2006 4:26 PM
Lance Harting: "To claim that anthropogenic climate change theory is on equal footing with the theory of evolution demonstrates a complete lack of understanding of the current state of one or both theories."
I agree; that's why I said no such thing. I pointed out that a very successful delaying action against a powerful scientific theory was a good candidate to be copied, when attacking another one.
Posted by: Barry | July 19, 2006 5:16 PM
George, look it up, please. Tell us how you learn the answer. It might help everyone to understand this discussion.
Posted by: hank | July 19, 2006 6:12 PM
Lance Harting: Some environmental NGOs and their attendant media outlets are pushing an aggressive "don't acknowledge the deniers" approach. It may be a good political strategy. It certainly isn't a valid scientific response.
I agree with what Davis posted above. If they're not publishing anything noteworthy, why would they merit acknowledgement?
Posted by: Jon Winsor | July 19, 2006 6:21 PM
According to Glen Raphael:
"If Mann & company had quickly and fully acknowledged their mistakes and made their data and methods available to other scientists for review, the problem would have disappeared in no time."
Yes and there would be no more global warming denialism.
Sure.
Posted by: Chris O'Neill | July 20, 2006 11:10 AM
George,
CO2 is well-mixed in the atmosphere. If this were not the case, then one would get very different results measuring CO2 on Mauna Loa than one would get at sea level. In fact, one doesn't.
I can't tell you the exact reason why this is the case but I think it basically has to do with the fact that gravity is not a very large player on the scale of molecules in a gas. That is, the effects of molecular collisions in the gas will overwhelm any "settling" effect that would occur due to gravity. (And, other effects such as convection will also overwhelm it.)
You might wonder why this is not true of liquids, i.e., that liquids of different densities do often separate. However, I think that has to do with the molecular interactions that bind things together so the effect size of the unit of liquid is larger. In fact, we know that even in liquids, you will not tend to get phase separation if the liquids are miscible in each other. (And, you will not tend to get separation if you dissolve solids into a liquid, e.g., sugar or salt in a water solution.) It is only when the liquids are immiscible and thus tend to form large conglomerates of their own kind that you can end up getting phase separation with the denser liquid on the bottom and the less dense liquid on top.
Posted by: Joel Shore | July 20, 2006 12:20 PM
Hank mentioned:
'Oh, Lordy Lord Lord Lord ..
'Wegman, at the hearings: "Carbon dioxide is heavier than air. I don't know where it sits with respect to the atmospheric profile."'
I just heard that on Morning Edition (I'm in Hawaii, so hear these things later) and was just staggered by that level of ignorance from someone pretending to be an expert witness. He also went on to say something about how it would reflect less infrared if it were at low altitude.
I once heard Limbaugh use exactly the same argument about CFCs not causing the ozone hole because they are too heavy. It's one of those things that sounds plausible but is so easily refuted that citing it as evidence reveals either profound ignorance or mendacity.
I don't mean to insult George--as I said, it sounds plausible so it's excusable from someone who doesn't pretend to be knowlegable.
Joel's explanation is essentially correct--CO2 is heavier, but it sinks so slowly that the winds keep it mixed well. In areas utterly lacking turbulence--caves and perhaps prarie dog holes, emitted CO2 can build up. In addition, at very high altitudes (>100 km?) collisions between gas molecules are so rare that there is a slight separation of gases based on molecular weight.
Posted by: Steven Howell | July 20, 2006 3:01 PM
Error in labeling that's worth noting in Wegman's report as currently posted (in a chart I believe was held up for the camera by one of the Representatives in the hearing).
http://www.realclimate.org/wp-comments-popup.php?p=328&c=1#comment-15917
Posted by: hank | July 20, 2006 3:13 PM
A poster says that if Mann et al had quickly acknowledged their mistakes and made data available the problem would have disappeared in no time. Forgive the word, this one time:bullshit.
How could it disappear unless there was nothing to it in the first place? If there was nothing to it in the first place, what was all the fuss about? If they (the Mann authors) were attacked when there was no real problem then they were the target of idiots or of those who seek to maintain the claim of uncertainty in climate (we don't really know so do nothing). Assuming the latter was the case then any little rock they could throw would do.
Indeed, that is what happened. The attack by M&M was contained in a series of peremptory written demands for a lot of information not prefaced by any showing of expertise at all. What scientist need answer such material at all? There is no such obligation.
When some information was nevertheless courteously supplied the "ratchet" was applied, that is, more insistent demands, and with increasingly tart remarks. This behavior did indeed lead to some of the recipients of these missives refusing to answer at all. The "paper" of M&M resulting from these efforts was eventually published in a sociological magazine, in no sense a refereed journal. Of 20 pages over 17 were devoted to a detailed review of petty errors, the sort of thing that is often found in academic writing which if corrected would not change the substantial findings or conclusions at all, much like fixing typos.
Yet this dismal review of "errrors" (many were not errors at all, and some were just a pretension of errors claimed to be found) tacked on to vague suspicions that somehow the upward tilt of measurements in the recent historical period could not be right was greeted with enthusiasm by the GW deniers. They had started out with scraping the bottom of the barrel on behalf of the coal and oil magnates and were always scrounging for some kind of useful argument.
Since then all that has happened is that one journal did accept and publish a short paper or note which complained that by using a period to establish a trend that was not the same as some other procedure that some other researchers might have used, the MBH work was wrong. The MM pair then turned out a revision of their paper, in the sociological magazine with this new claim. This is a point requiring expert comparison, and it has turned out that whether one or the other method is used makes no substantial difference, so all that has been produced is a statistical curiosity that sheds no new light at all.
Since then M&M have beavered away seeking to turn their embarrassingly little pile of sticks into a mountain from whose top they may hurl nasty accusations at the Mann group of authors, a group that grows larger in their accounts as this unpleasant pair, (who cannot share a climate science qualification between them) discover more and more scientists they suspect of knowing each other and even (can it be?) going to the same data sources.
Somebody should tell them that is why organizations and funds are created to gather data and render it so the whole academic community can share it at low cost.
M&M have never appeared to be scientists or persons interested in learning about science. No one could read their eary demands for information and statements without thinking that they were not likely to get much co-operation if they talked like that. They have been concerned to attack the hockey stick from the outset. Unfortunately the most likely outcome of their final and abject failure is that many a researcher will be far less open about their opinions, and information developed than was the case in the past. The M&M campaign with its supporters among the rif raff of deniers has injured the public interest.
Posted by: garhane | July 20, 2006 4:11 PM
Hank,
If you have a look at the the report itself (not at the link of RC), you will notice that Wegman explicitely says for Fig 4.3 in his report (page 32) that the graph showing the difference between decentered/centered methods is about the PC1 of the N.American network, not the full MBH reconstruction.
He also comments on the relevance of bristlecone pines in the N.American PC1, with and without the methodological differences, on page 81.
Posted by: Ferdinand Engelbeen | July 20, 2006 4:15 PM
Steven Howell said" In areas utterly lacking turbulence--caves and perhaps prarie dog holes, emitted CO2 can build up."
Phew. For a minute there, I thought Joel had blown a hole clean through my prairie dogs and their desire for a better (CO2-free) world.
Now I can feel confident in submitting my theory about CO2 for publication in the "Journal of Prairie dogs and climate".
To be quite frank, all this talk about gravity, molecular collisions, density, miscible(?) and turbulence is making my brain turbulent.
Why can't we just go back to the days when hockey sticks were only used for playing hockey? (and when the length of the stick handle for an average blade was less than 12 feet)
And can't we all just get along?
Where's the Rodney King of the Climate Riots when you need him, anyway?
Posted by: George | July 20, 2006 6:21 PM
garhane, your attack on M&M indicates a selective blindness indicative of willful deception. The less inflammatory conclusion would be that the deception is self-induced.
Perhaps your most ridiculous remark is, "The attack by M&M was contained in a series of peremptory written demands for a lot of information not prefaced by any showing of expertise at all. What scientist need answer such material at all? There is no such obligation."
Then you lament the damage done to science by these knaves that dared question your heroes by being impertinent enough to actually see the data that backed up the study.
Uh, excuse me? Speaking as a scientist I wasn't aware that one need present proper credentials to see the data supporting a scientific study. In fact openness and transparency are absolutely vital to rigorous and productive science. As a university physics instructor I teach students to present all their data, even data that may have been discarded for legitimate reasons, and to show clearly how that data was used to reach their conclusions.
This is one of my biggest problems with climate modelers. The great majority of them do not make their data sets available, let alone their source code. They also often don't reveal the "tuning" that is done to get the models to even approximate real empirical parameters.
It is clear that you see science as an "us vs. them" political struggle. Thankfully the NAS panel disagrees with you and chided Mann for his lack of openness as well as other deficiencies in his work.
I have spent a fair amount of time reviewing McIntyre and McKintrick's work. I find it to be forthright and diligent. If you have a problem with it you are free to voice any and all objections at their website climateaudit.com. Unlike Mann's Realclimate their work is quite accessible including their data sets.
I suspect you would rather make ad hominem attacks from a distance than actually spend time thoughtfully reviewing their work and addressing any reasonable criticism to them personally. You seem to view any scientific criticism of studies that support your political position as an attack by "idiots" and "rif raff deniers" on orthodoxy rather than the mechanism of healthy scientific inquiry that it actually represents.
Posted by: Lance Harting | July 21, 2006 1:58 AM
Lance Harting: I wasn't aware that one need present proper credentials to see the data supporting a scientific study. In fact openness and transparency are absolutely vital to rigorous and productive science.
The reason why they don't release raw data to non-scientists is perfectly understandable. As the Washington Post put it in a recent story:
http://www.washingtonpost.com/wp-dyn/content/article/2006/05/23/AR2006052301305_pf.html
If people are acting more like hostile attorneys than good-faith members of the scientific community, then why give them all the raw data they need to make a misleading case? If it's clear that the only purpose they'd have with the data is to publish it outside peer-reviewed venues, and they don't have the background to evaluate it anyway, why give it to them?
Posted by: Jon Winsor | July 21, 2006 11:15 AM
Jon, your suggestion that data only be provided to the "right people" is emblematic of the politicization of climate science. Science is not served by the formation of cliques.
The statistical methods used by Mann et al have again been criticized by Wegman, Scott and Said, three eminent statisticians that report that Mann's methodology will give "hockey stick" results even when random red noise is used as data, just as McIntyre and Mckitrick had concluded.
Even more sanguine to the discussion is this statement in the report.
"It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to be interacting with the statistical community. Additionally, we judge that the sharing of research materials, data and results was haphazardly and grudgingly done. In this case we judge that there was too much reliance on peer review, which was not necessarily independent. Moreover, the work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility. Overall, our committee believes that Dr. Mann's assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year of the millennium cannot be supported by his analysis."
I'm sure the dirty laundry squad is searching for a way to smear these respected scientists. How dare they crash the party!
Posted by: Lance Harting | July 21, 2006 2:19 PM
Lance H. wrote:
Jon, your suggestion that data only be provided to the "right people" is emblematic of the politicization of climate science. Science is not served by the formation of cliques.
"The right people" is probably an overstatement. You just don't want to help those people whose motives are not scientific, but rather political. You don't help those who are out to damage you or your reputation. Scientists, like anyone else, have a right to ask "Who wants to know?" before sharing information.
If the raw data and methods are withheld from those doing peer review of a publication, you may not be able to publish. People doing classified research or who are involved in trade secrets have that problem, too. Is anyone saying that the referees of the "hockey stick" publication were denied access to information they considered critical to passing judgment here? Or are the referees being accused of not being properly diligent?
I can't speak to whether climate scientists are retreating into cliques; but to me, the politicization was at its worst when the administration tried to silence Jim Hansen when he was trying to be open about his work and conclusions.
Posted by: Fred Bortz | July 21, 2006 2:59 PM
Unfortunately, the nearly universal use (and sometimes misuse and even outright abuse) of statistics has basically supplanted the presentation of all the data.
It is wise to question any argument that is based on statatistical results alone. This is because even an argument that uses statistics correctly can still be "wrong", ie, lead to false conclusions. As Gomer Pile used to say, "Surprise, surprise, surprise."
It should also be noted that using statistics (or math in general) incorrectly need not necessarily lead to a false conclusion about the real world. Johannes Kepler made math mistakes and nonetheless came to the right answer about the planetary orbits.
By the same token, a demonstration that statistical analysis was performed incorrectly need not reveal anything about underlying reality, In particular, this alone does not demonstrate that the conclusions reached (based on incorrect statistical analysis) are false (do not jibe with reality).
In that regard, the question about whether statistics were properly used by Mann et al is basically a side show to the main event.
The critical question is whether humans have had a significant effect on the earth's climate. For answering that, the Mann paper is just one piece of evidence (though, for whatever reason, it has long been the center of attention).
Posted by: Dark Tent | July 21, 2006 3:35 PM
I'm all for having the best review process possible. But my point is that there are a lot of special interests with PR machines ready to spin the significance out of any of these studies to the point where they're unrecognizable. Just look at how the word "plausible" was parsed to death after this last NAS report was released. Could you imagine what folks would do to a full raw data set? The CEI, Heritage Foundation and whoever else would descend like piranas.
I don't know the details of the processes paleoclimate scientists use to review their work. Maybe there are ways they could be improved. But this is a side issue anyway, because as Chris notes above, this is just one study, and an eight year old one at that.
But my point is that there's a lot of people out there who spend lots of time doing sophistry, not science. So I don't blame scientists for not wanting to put out raw data that anyone with a think tank and a large budget can pour over at will.
Fully qualified people with real scientific business to perform are another matter, of course.
Posted by: Jon Winsor | July 21, 2006 3:44 PM
So far as I can tell McIntyre and McKitrick were motivated by what they saw as characteristics indicating a common misapplication of PCA methods in Mann's results. They are not oil industry stooges nor do they work for the Competitive Enterprise Institute or any other "think tank".
The NAS report played both sides of the fence a bit but nonetheless validated some of their criticisms of MBH98. A panel of respected statistical scientists has now backed up their work. The "hockey stick" is dead!
To then try to down play Mann's work as "just one of many" studies after passionately defending it previously strikes me as "sour grapes". It is after all the main study upon which the IPCC report based its dire conclusions. In fact the "hockey stick" is on the cover of one of the main parts of the IPCC report and has been splashed all over the Internet and media in general as proof of our imminent demise.
Also I note, so far, no one has responded to the panels criticism of the insular and politically strident nature of the main players in the climate science "consensus".
The report appears to be a call for the climate science community to return to the normal practices and procedures common to the main body of science.
Posted by: Lance Harting | July 21, 2006 8:47 PM
Nonsense. That's a big PR talking point right now, and it's fooling people who don't check their facts.
Who do you rely on for what you believe? Who's telling you that story? Why do you believe them?
It's one study among many, supported later by many others. The myth that science relies on "original truth" and all subsequent work depends on early work is very attractive to those whose worldview depends on revealed truth.
Here's Inhofe, illustrating the same talking point -- and the same lack of understanding about how science works:
http://thinkprogress.org/2006/07/21/inhofe-gore/
Posted by: Hank Roberts | July 21, 2006 9:40 PM
Lance Harting: To then try to down play Mann's work as "just one of many" studies after passionately defending it previously strikes me as "sour grapes".
I don't think so. This is from a Coby Beck post early this year:
I believe the Realclimate posts I've read usually say something similar to this last paragraph.
By the way, Realclimate has a new post up on "what the effect of the PC centering changes would have had on the final reconstruction..."
Realclimate shows what the "hockey stick" looks like with the PC centering changes:
http://www.realclimate.org/index.php/archives/2006/07/the-missing-piece-at-the-wegman-hearing
If the hockey stick is dead, looks like we've got a night of the living hockey sticks on our hands.
A disclaimer: I'm not a climate scientist and I can't claim to know much about "PC centering." But the more I read, the more this whole flap seems like much ado about nothing...
Posted by: Jon Winsor | July 21, 2006 10:26 PM
Ya know, they're right. It's not a 'hockey stick' at all.
The handle IS a little more curvy, in the other charts.
"... These other reconstructions do tend to show some more variability than MBH98, ie the handle of the hockey stick is not as straight ...."
http://www.dragonquestfrontiers.com/sitebuilder/images/scythe-155x299.jpg
We know what this is, don't we? And what it symbolizes?
Posted by: Hank Roberts | July 21, 2006 11:26 PM
On what do you base this gem of a statement?
http://www.grida.no/climate/ipcc_tar/
I don't see it on any of these covers.
Posted by: Davis | July 22, 2006 4:22 PM
In their recent report Surface Temperature Reconstructions for the last 2000 Years, NAS scientists expressed doubt about (placed low confidence in) Mann's claim that "the 1990's are likely the warmest decade and 1998 the warmest year in at least a millenium".
But the same NAS report also stated that "surface temperature reconstructions [like those of Mann et al] for periods prior to the industrial era are only one of mulitiple lines of evidence supporting the conclusion that climatic warming is occurring in response to human activities, and they are not the primary evidence."
http://darwin.nap.edu/books/0309102251/html/4.html
So, the NAS scientists who wrote that report clearly did not believe that the results of Mann were essential to the broader conclusion that AGW is real.
But there may nonetheless be some out there who do believe that the Mann results are essential to that conclusion.
To them, I would make the following request:
Please explain how the conclusion that AGW is real is contingent upon the accuracy of the specific results/conclusions of Michael Mann.
Posted by: Dark Tent | July 22, 2006 9:19 PM
>Is anyone else as sick as I am of repeated attacks on the "hockey stick" reconstruction of past temperatures?...
>>One study never definitively proves anything in science. Any single study can be attacked and criticized. Any individual piece of work will have its gaps, shortcomings, and associated uncertainties.
So let's see if I get this argument. We mustn't criticise the MBH'98 hockey stick, but science operates by a process where it finds the errors in bits of work. Isn't this kind of asking for MBH to be taken away from the normal process of scientific scrutiny ?
Posters have made the point that the Millikan oil drop experiments (a century old ?) can effectively be repeated, even after all this time. By contrast, both north and wegman gave evidence that the method of MBH98/99 was flawed.
>Whether the "hockey stick" is right, wrong, or irrelevant, the underlying message on global warming is that we're causing it.
The NAS report went out of its way to say that MBH didn't directly impact on AGW theories, and wegeman didn't touch on AGW. So why are you so damn nervous when no-one even mentioned the subject ?
yours
per
Posted by: per | July 23, 2006 5:14 PM
So why are you so damn nervous when no-one even mentioned the subject ?
There are some people (not us) who want to hash this subject out ad nauseum and use it as a political football, when, as Chris says, this study is a small part of a much larger and conclusive body of evidence. This is from a recent Inhofe television appearance:
http://thinkprogress.org/2006/07/21/inhofe-gore/
It's fine to criticise a study (although there will be a good chance that some of your criticisms will be moot after 8 years of continued research). But when you use a purported flaw in an eight-year-old study to distort an entire body of evidence, as Inhofe is doing in this TV appearance, the public is being bamboozled. So people like us end up shaking our heads and wondering when the adults will be in charge.
Posted by: Jon Winsor | July 23, 2006 6:25 PM
A panel composed of different scientists, the NAS panel, explicitely wrote in their report: 'strip-bark' samples should be avoided for temperature reconstructions.
That means that most of the current reconstructions (not only MBH98/99) simply are unreliable. And only reconstructions without such tree series (bore holes, Huang) or with a restricted influence (Moberg) should be taken into account. Both show a much lower LIA than MBH98/99 in the pre-industrial period.
This has important consequences for climate models and future projections. If there was more natural variability in the pre-industrial past (and thus in current times), then the influence of GHGs/aerosols is less than currently implemented, because models must fit the instrumental 1.5 century temperature curve...
Posted by: Ferdinand Engelbeen | July 24, 2006 5:04 PM
Focusing on the the issues with tree ring (and other surface temperature) proxies misses the forest for the trees.
The recent NAS report stated clearly that the surface temperature reconstructions are not the primary evidence in support of AGW..
They did so in the section of the report under the heading "How central are large-scale surface temperature reconstructions to our understanding of global climate change?"
"Large scale surface temperature reconstructions for the last 2,000 years are not the primary evidence for the widely accepted views that global warming is occurring, that human activities are contributing, at least in part, to this warming, and that the Earth will continue to warm over the next century."
http://darwin.nap.edu/books/0309102251/html/22.html
After the above quote, they go on to list
"The primary evidence for these conclusions" on this page.
They conclude the section under the above heading with the following statement:
"Surface temperature reconstructions for the last 2,000 years are consistent with other evidence of global climate change and can be considered as additional supporting evidence. In particular the numerous indications that recent warmth is unprecedented for at least the last 400 years and potentially the last several millenia, in combination with estimates of external climate forcing variations over the same period, supports the conclusion that human activities are responsible for much of the recent warming. However, the uncertainties in the reconstructions of surface temperature and external forcings for the period prior to the instrumental record render this less conclusive than the other lines of evidence cited above. It should also be noted that the scientific concensus regarding human-induced global warming would not be substantively altered, if for example the global mean surface temperature 1,000 years ago was found to be as warm as it is today."
http://darwin.nap.edu/books/0309102251/html/23.html
Posted by: Dark Tent | July 24, 2006 7:06 PM
>Please explain how the conclusion that AGW is real is contingent upon the accuracy of the specific results/conclusions of Michael Mann.
contingent is far too strong, but the strongest case I can point you in the direction of is in the summary for policymakers of the IPCC TAR.
You appear to be jousting at windmills. Neither the NRC nor the wegman report made any case that their reports invalidated AGW. Why do you repeatedly bring this up ?
I will say this: that Jon Winsor says the public is being bamboozled. Well this is true; the hockey-stick graph has been hard sold for the last 8 years, and is still being used as publicity material. We now know that the scientific basis for the MBH hockey-stick is inadequate; if that ain't bamboozling the public, I don't know what is.
yours
per
Posted by: per | July 24, 2006 10:26 PM
The obvious point is that without removing evidence for previous natural climate variability form the discussion, as MBH98 attempted to do, there is no consensus that unusually large, dangerous increases in global temperatures are occurring or have occurred.
This returns the "consensus" to the somewhat uncontroversial and non-alarming, "The temperature has risen approximately 1 degree Celsius over the last 100 years, that a concurrent 30% rise in atmospheric CO2 may have contributed to that rise and that humans are at least partly responsible for the rise in CO2."
I know this doesn't dovetail with the plans of some to use this "issue" as a hammer to alter the political landscape but science isn't meant to be a political tool.
Posted by: Lance Harting | July 24, 2006 10:52 PM
Well if it will stop some people from throwing fits, they should stop using the MBH98 graph and use the other graphs. But it's quite silly to call the use of a graph from a peer reviewed study "bamboozlement".
Mann called attention to the uncertainties of his own study when it was published. It would be very surprising if the IPCC hadn't taken these kinds of uncertainties into account with its predictions of a 1.4 and 5.8 C degree increase over the next hundred years (that is, if Mann's study hasn't been superseded over the last 8 years).
Posted by: Jon Winsor | July 25, 2006 12:09 AM
>Mann called attention to the uncertainties of his own study when it was published.
was that the claim that it was 99.7% certain that the '90s were the hottest decade since 1400 ? The NRC dismiss the 0.3% figure as a realistic assessment of uncertainty.
When he calculated r2 statistics for his 15th century reconstruction, found them to be adverse, then didn't tell anyone, is that telling everyone about the uncertainties ?
When he made the claim that his reconstruction was robust to the absence of tree proxies, and in fact it doesn't survive removal of the bristlecone pines, is that telling everyone about the uncertainties ?
You have confidence that subsequent reconstructions improve on MBH. Strangely enough, I have little faith that they do. The NAS report concluded that bristlecone