Need proof of Global Warming

Great Debates
81

So are we to assume that the models accurate hindcasting of the short historical downturn around 1955 was just dumb luck? I mean, they hit the start of it exactly, and they predicted the first 5 years of it as well as the last 5. The short time span didn’t bother the models then in the slightest. So why should it suddenly start to bother them now?

However, you know as well as I do that the point was not central to my argument, which is that whether tuned climate models can hindcast the 20th century climate with or without anthropogenic forcings means nothing. Since the modelers have control of both the forcings and the parameters, and since the models are carefully tuned to replicate the 20th century climate, I would be very surprised if they could not hindcast the climate.

The argument goes like this:

  1. We can tune the models to replicate the historical climate with anthropogenic forcings.

  2. However, once the model is tuned, when we take out the anthropogenic forcings, the model doesn’t replicate the historical climate.

  3. Therefore, the anthropogenic forcings are necessary to explain the 20th century climate.

Perhaps aptronym can’t see the flaw in that argument, but I’m sure you can.

w.

82

By the way, the appropriate section of the full IPCC Working-Group report to read on this is Chapter 10, specifically Section 10.7.4.

83

The flaw in the argument is that it is an incorrect description of what is actually done. This ought to be obvious to you (if not from reading the papers themselves) just from the fact that, if that was what they were doing, they would probably not be able to so easily convince reputable scientific organizations such as the National Academy of Sciences and the Royal Society. Do you think you are the only one capable of seeing scientific flaws? When your understandings are at odds with many very smart and capable scientists, doesn’t it ever occur to you that it is you who might be wrong. Or, is it always “Everybody is out of step but my Johnny”?

By the way, I am still waiting for you to give me a cite where someone has tuned a climate model to reproduce the 20th century climate change using only the natural forcings, something you apparently believe can be done but have never been able to show any evidence for.

84

Who constitutes “we”? You have stated before that you have expertise in climatology. Do you speak for yourself, some selected group of climatologists, climatologists in general, or for all humanity?

That is not my main argument at all.

The main argument is that of the radiative forcings we can quantify - CO[sub]2[/sub], CH[sub]4[/sub], NO[sub]x[/sub]'s, ozone, aerosols, solar variation - that CO[sub]2[/sub] dominates and is twelvefold larger than natural components. You don’t need any sort of computer models for this. It’s calculable from first principles (e.g. cross-section of CO[sub]2[/sub] normalized by the blackbody emissions of Earth).

Moreover, this domination is actually large enough to withstand most of the credible attacks from Lindzen et al - if, as Lindzen claims, people have overestimated the contribution of CO[sub]2[/sub] by threefold, then it still stands that CO[sub]2[/sub] is four times more potent than solar variation.

Generally true, but I have to nitpick. The wide ranges of estimates tend to collapse under economic assumptions - that is, the question of how large China’s economy will be in 2050 has a larger impact on model results than unanswered questions about aerosol sensitivity. When you look at similar economic assumptions, the ranges go down by quite a bit: +1.1 to +2.9 [sup]o[/sup]C for the B1 scenario, for instance. I agree that there is a large range in the predictions (A1F goes from +2.4 to +6.4 [sup]o[/sup]C) but I would not use that as evidence that the predictions are unreliable.

I agree this is an important question to be answered.

Again, generally true, but to nitpick: AGW doesn’t predict those things. Anthropogenic Climate Change predicts those things. The question of global warming is independent of what occurs regionally as a result of warming. For example, global warming may lead to some short-term regional cooling. But AGW deals with things on a global scale.

I’m not putting a ton of effort into explaining these latter questions because, as you agreed, questions (1) and (2) really need to be agreed on before these can be addressed. You have a viewpoint on (3) and (4) which are consistent with your belief in (2).

I probably would have lumped this response in with the next one had it not been for the snarky comment at the end. In my first post, I very clearly addressed the issue of the IPCC’s bias (which I will do so again after the next quote). So the whole “pursuing ignorance” remark is not only unwarranted, but something that I might reflect back to you. I have never glorified the IPCC, and explicitly questioned their reliability in my first post. Why, then, are you posting this?

Because of the NAS. The IPCC has many flaws - one fundamental one which you didn’t bring up is that its scientists are selected by politicians. By itself, the IPCC report really couldn’t be considered more than political propaganda, I wholeheartedly agree.

However, the U.S. National Academy of Sciences is probably the most respected group of scientists outside of Nobel Laureates. It was born 150 years ago, long before the Industrial Revolution, and propagated since then outside of the political process. Scientists nominate other scientists they consider to be worthy, and invitation to membership is one of the highest honors for an American scientist. More importantly, however, the NAS is funded by Congress and is specifically charged with making independent recommendations on policy-related scientific matters. In 2001, a Republican-dominated Congress charged the NAS with studying global warming.

Can you give a single reason why this body cannot be trusted?

And yet, the direction and magnitude of the greenhouse effect can be derived from a single equation!

I agree with you in the general sentiment - in order to answer any of the most relevant questions, our understandings of regional climate (question (3) above) and magnitude of effects (question (4) above) have to be much, much better. This is a sentiment which is echoed in the IPCC reports as well as the NAS report.

I do not agree with your specific sentiment that we cannot express with high confidence answers to questions (1) and (2) because of that.

85

By the way, do you care to provide a cite or figure for what you are even talking about here? When I look at the HADCRUT3 record for that period, I don’t even see the trend that you are talking about…In fact, the short-term trend between 1955 and ~1962 or 1963 is warming, although between 1952 and 1956 it was cooling, and between 1962 and 1967 it was cooling again…thus illustrating the sort of dramatic changes in trends one gets by looking over such short periods where internal variability (and other things like volcanic eruptions) can be so dominant.

86

jshore, ever onwards. Thanks for your reply.

jshore, I don’t think I’ve ever said that anyone has reproduced the historical climate without anthropogenic forcings, although sometimes I’m posting very tired, so I suppose it’s possible. But as far as I know, none of the climate modelers have seriously tried. Do you have any citation showing that they have tried and failed? (I can’t imagine them trying very hard, since if they succeed, they’re out of a job … but I digress.)

In any case, here’s another description of the process, from the IPCC:

Regarding this claim, the IPCC in turn references Stott et. al, External control of twentieth century temperature variations by natural and anthropogenic forcings. Science, 15, 2133-2137, which says:

I’m afraid I don’t see the difference between the IPCC’s description of what was done, Stott’s description, and my description. For reference, I said:

Perhaps, since you see some huge difference, you could explain to me what the difference is. Which part of my description is incorrect?

w.

PS - you say:

Of course it occurs to me, don’t be foolish. It also occurs to me that they might be wrong. And in the event, sometimes it’s them, and sometimes it’s me. How many “smart and capable” scientists thought the Hockeystick was good science? I didn’t, and in the event, I was right and all of those “good and capable” scientists were wrong. As I have been wrong myself, many times.

PPS - You ask for a reference regarding the match of models to historical data. The Stott paper shows the model response to “ALL” forcings to be a most excellent match to historical temperatures. In particular, the turning points in the climate (where warming became cooling or vice versa) are all picked up by the model runs within two or three years of the turning.

That’s why I say it is odd that the models were unable to predict the current cooling. Every other change in the historical record is picked up by the models with only a few years error … so why couldn’t they pick up this one?

You say it’s because this is just a internal variability in the climate … but if that’s the case, why is there not one similar occurrence of natural variability in the 150 years covered by the Stott paper that the models didn’t catch? The models do really, really well for 150 years, and then they go off of the rails as soon as they are “out-of-sample”, and your explanation is natural variability? The model runs in the Stott paper show absolutely no change in the upwards rise of temperature from 2000 onwards, no reversals, no leveling off, just an upwards climb that so far is not happening.

Finally, is there an explanation for this “internal variability” you speak of? I mean, temperature change doesn’t happen without energy, and energy doesn’t come from nowhere or suddenly just vanish, there must be some change in the natural forcings to explain it … but what is the explanation for the level temperatures of this century? The Stott models show a 0.3°C/decade warming for all of this century, so whatever the explanation is, it needs to be strong enough to cause a -0.3°C/decade cooling. Which is a whole lot of cooling.

I don’t think you have thought your “internal variability” argument all the way through to the end. Because if there is a natural “internal variability” that can cause the models and the temperature to diverge for a decade, then this variability must be caused by some unknown natural forcing … but that, of course, means that Stott et. al did not include all of the natural forcings in their “NATURAL” runs …

My best to you, jshore, to the other contributors to the thread, and to all the lurkers as well.

87

aptronym, I will answer your interesting missive in due time, but first, I must apologize to you. You say:

I had thought that when you said

that you were supporting the authority of the IPCC.

However, whether I was right in my assumption or not, my snarkiness in my reply was totally and absolutely unwarranted, and you have my profound apologies for my transgression.

More later,

w.

88

I too would like to know how exactly intention’s description was incorrect. Having looked at the abstracts of the papers in question (there were only 3 or 4 as I recall), as well as the IPCC graphs of their output, it seems to me that his summary was essentially correct.

And the fact remains that those models fit beautifully to the historical temperature record. That’s either because the models are extremely skillful or extremely tuned. If it’s true that the models go “off the rails,” it’s a strong indication that they were aggressively tuned.

89

aptronym, you say:

I thought you were going to pose me a tough question. Heck, I’ll give you a dozen.

  1. Trust, but verify. I don’t automatically believe any scientists or any group of scientists, eminent or not.

  2. Their house organ, PNAS, allows members to pick their own reviewers for things to be published in PNAS. Any organization that does that does not deserve to be called a scientific organization. Having your papers reviewed by your friends is a cruel distortion of the scientific process.

  3. The climate scientists at the NAS stood around and did not take a stand when Michael Mann was shown to be a fraud and a liar. Doesn’t make me want to trust them in the slightest.

  4. The NAS includes such “eminent scientists” as Stephen Schneider, who think’s it’s OK to lie about science in the pursuit of a policy goal … trust coefficient = 0. He told us he would lie if it suits his purposes … why would anyone ever trust him?

  5. Out of the 2,100 scientists in NAS, only 1% (21) list their field as climate.

  6. James Hansen is a member, and I don’t trust a word that comes out of that boy’s mouth. I’ve investigated too many of his studies, found too many errors, and seen too many of his “artful dodger” type of constructions to believe anything he says. He plays fast and loose with the truth. In addition, I pay his salary, and I don’t recall anything in his job description about giving hundreds of press conferences on my dime, and then claiming he is being “muzzled”. I wish he was, I wish he just did his job and stopped trying to be a politician.

  7. Kerry Emanuel is a member. I have not found his claims to be very reliable. He tends to exaggerate his conclusions.

  8. Susan Solomon is a member, and she did an abysmal job with her participation in the AR4. She actively squashed opposition to her beliefs in a most untrustworthy manner. She’s a real piece of work, that one.

  9. Paul Ehrlich is a member. You might recall Paul, he famously predicted global cannibalism from overpopulation by 1980 … do you trust his scientific judgement? I don’t.

  10. The NAS report on the Hockeystick controversy was totally schizophrenic. On the one hand, they said not to use bristlecone pines in temperature reconstructions. On the other hand, they cited two such reconstructions using bristlecones to support the Hockeystick claims. How can you trust an organization that talks out of two sides of its mouth like that? There is more detail here. READ THE CITATION! The NAS was offered a chance to take an actual stand on the science, and they wimped out. I’m amazed anyone trusts them after that fiasco, but I guess the credulity of the public when it comes to the high priests of “science” knows no bounds.

  11. I don’t trust climate scientists as a class. I’ve seen too much shuck and jive, too many unsupportable conclusions, too much omission of things like error estimates, far, far too much abysmal statistics, too many elementary errors, and way too much climate nonsense that has passed peer review to ever take anything a climate scientist says as fact without extensive analysis.

  12. While you think it is great that the scientists are selected by other scientists, I do not find that comforting at all. That just tells me it’s an old boy’s network, one that is extremely unlikely to actively seek out members who don’t believe whatever the current membership believes. It is certainly not any kind of bulwark against charlatans. This is particularly true when there are already a number of quite questionable folks who are members (see above) … if I don’t trust them, why should I trust someone they select?

Yes, there are some good, even some great scientists who are members … but there’s also some people in there who are as far from following scientific principles as one can get. Trust them at your own peril.

A round dozen reasons.

My best to you,

w.

90

Thanks for your reply, intention.

So, your argument is that the model could easily be tuned to give a good fit to the data with only natural forcings but somehow with all the various scientists and climate models out there who could have tried this, none ever have? That sounds like a pretty nice conspiracy theory to me.

Where is the part where they said that they tuned the model to fit to the historical global temperature record? (By the way, the latest IPCC report shows continent-by-continent comparisons for all continents except Antarctica, so there they would have to presumably tune the model to fit all 6 of these records.)

Well, I think part of the problem is that you decide you are right in cases where others would disagree. At any rate, this gets back to a basic problem with all of your arguments here in that I don’t really know what your purpose is. You are essentially trying to convince us to believe you over the IPCC, the NAS, and a whole bunch of reputable scientists but it is not clear why we should do so, except that in your estimation these scientists have made numerous errors. Unfortunately, the rest of us may not see what you perceive to be errors to really be errors or to be very egregious ones and we may see some of the things you see and some of the arguments that you have endorsed to be very erroneous.

So, at the end of the day, are we supposed to trust that someone who has published something like 2 papers in the field (an online comment in a reputable journal and a paper in a not very reputable one)…and in fact, as far as I can tell, in any scientific field…over all these other organizations, scientists, etc?

I simply don’t see what you are talking about here. I think if you looked carefully at the Stott results, you would see that same sort of divergences from the year-to-year climate record as we have seen in the last 7 years. You are creating this apparent discrepancy by exaggerating the extent to which the Stott et al. simulations agreed with all the details of the global temperature record and then exaggerating the extent to which the years since 2000 have diverged from the Stott et al. prediction. In fact, it is quite easy to see this latter point from their figure 1 (this link probably requires a subscription). In that figure, you can see that the peak in the instrumental temperature seen in 1998 is not exceeded in their simulation for something that I measured off of the graph to be ~9 years and then only barely…and then it is another ~9 years before it is exceeded again, again only barely. From that observation alone it is readily apparent that the supposed dramatic divergence that you claim one would see if you overlayed the last 7 years of the historical temperature record over the Stott et al. simulation is purely a figment of your imagination.

My best to you, intention…and all reading this…also.

91

I’m afraid that you lost me there. What single equation gives us the magnitude of the greenhouse effect?

And how can we determine the size of the human influence on the climate (question 2) when we don’t understand the natural influences on the climate?

Like I said, you lost me.

w.

92

I didn’t really want to get into this discussion you are having with aptronym of why you don’t trust the NAS either but I thought I would comment on this particular item since it is the most defamatory (well, perhaps other than the Michael Mann one, but I’ll let you have your one great Satan because frankly I am sick of arguments about the hockey stick). In fact, Stephen Schneider is a very eminent scientist, one who has been in this field for a long time, and one who has probably thought more about how one communicates with the general public the state of science and the nature of the uncertainties than nearly anyone else. Your beef with Schneider apparently comes from one statement that he made in an interview that was often taken out-of-context (and sometimes even added to or “paraphrased”) and was interpreted by you and others in the most uncharitable possible light. Here is Schneider discussing the statement that he made. Frankly, I think this item says more about your own biases than it does about Schneider’s trustworthiness.

93

jshore, you and I have discussed this before, and you complimented me on providing the full quote, as is my habit. I don’t want to take it out of context. Here it is again, so everyone can decide …

Now you are a scientist, jshore. Are you following Schneider’s advice?

• Are you offering up scary scenarios?
• Are you making simplified, dramatic statements?
• Are you keeping your doubts to yourself?
I’m 100% serious on these questions, jshore. If you agree with Schneider, can we trust you not to lie to us about the state of climate science just because you happen to have an agenda?

Me, I think Schneider’s statement is a load of bollocks. He says scientists “have to offer up scary scenarios” … not in my book. Giving scary scenarios, that’s the job of politicians and scaremongers. Giving accurate scenarios is the job of scientists.

And more importantly, IT IS NOT THE JOB OF SCIENTISTS TO HIDE THEIR DOUBTS. Their doubts are one of the most valuable things that they have to offer. It is very important to know, without quibble, the current state of science. I don’t want Stephen Schneider to bullshit us that the important questions in climate science are all settled, just because he has decided it’s more important to lie to further some private agenda.

It is precisely because scientists talk of climate change in these Schneiderish absolute terms (“the science is settled”, “there is a consensus”, “we know”), rather than honestly revealing their doubts, that we are in this place we find ourselves now.

By and large, we can depend on politicians to lie. And by and large, there was a time when we could depend on scientists to tell the truth. Now, however, there’s no telling, particularly with climate scientists. When Steven Schneider says he is “certain” about something, when he says the science is “settled”, is he telling the truth, or is it just bullshit? And more to the point … how could we possibly know the difference?

That’s why I don’t trust him. As I said before, he thinks it’s OK to say “I am sure” when the truth is “I’m not sure”. Perhaps that is OK with you, every man has to make his peace with telling the truth. For me, that is a lie, and it makes a mockery of everything that science stands for.

I await the answer to the question of whether you have been following Schneider’s ‘scientific guidelines’ …

My best to you,

w.

PS - The perils of offering up “scary scenarios” have been dealt with very adequately in an ancient folk tale:

That’s why I despise Stephen Schneider. After enough “scientists” give us enough scary scenarios, nobody will believe scientists, even when they are telling the truth.

PPS - Describing Michael Mann as a “great Satan” is your fantasy, not mine. He’s not Satan, he’s just some poor shlub who seems to have taken Schneider at his word and decided to offer up scary scenarios with no scientific foundation, and to hide his doubts (in his CENSORED directory, where to his detriment they were discovered and published) so no one would know about them.

94

Well, I do appreciate you providing the full quote. It is also useful to provide Schneider’s discussion of the context of the quote and what he meant by it:

As Schneider explains, that is not his advice. I am not following your interpretation of what his advice is. Rather, I am trying to follow the actual advice that he explicitly gives in what I quoted above and following his example of how he has actually conducted himself (at least to the extent that I know…I have to admit that I haven’t studied a huge proportion of what he has written).

Well, of course, it is easy for you to say this since giving scary scenarios would be exactly contrary to your own agenda. I think the question that you should ask yourself would more be along the lines of: “Do I exaggerate the uncertainties that exist?” “Do I consider the possible consequences if I am wrong and the bulk of the scientific community is correct in their assessment of the certainty and uncertainty with which they know certain things?” and so forth.

Well, I don’t know exactly what was in this supposed directory, but as I understand it, it basically contained results that showed the sensitivity of the result to the Southwest U.S. bristlecone pine data set and was summarized in this 1999 paper in Geophysical Research Letters appropriately titled “Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations” (Hmmm…Bad title for someone who is trying to “hide his doubts”):

If I were Mann, I would try to find a better way of hiding the dependence of his result on a certain piece of data than talking about it in GRL.

All the best to you.

95

I have read his apologia, and I find it singularly unconvincing. Hey, call me naive, but when a man says we “must” strike a balance between honesty and effectiveness, I take him at his word. Not only that, I take him at his word even when he tries to talk his way out of having said it.

His explanation does not address, let alone explain the fundamental questions. Why on earth should a scientist balance honesty and effectiveness? Why should he supress and minimize his doubts? If he can only be effective by lying, he’s on the wrong road. The “soundbite” issue Schneider raises is a red herring – you can tell the truth or not tell the truth even if you have only one sentence to express it.

There is no “double ethical bind” between effective and being honest. Schneider seems very fond of the “double ethical bind” idea, referring to it above as a key part of what he said.

But in this case, it doesn’t exist. Indeed, we do have an ethical duty to be honest, particularly scientists. It is fundamental to the scientific process.

But we have no corresponding ethical duty to be effective. Where is the “double bind”? Is there an “ethical double bind” between lying to get an ice cream cone, and telling the truth and not getting an ice cream cone? Yes, there’s a moral duty not to lie. But there’s no more an ethical duty to be effective than there is an ethical duty to get an ice cream cone. To have a double bind you need to have competing ethical duties. In this situation, there is only one ethical duty, which is to be honest.

Obviously, you think that Schneider meant something else when he said each of us “has to” strike a balance between honesty and effectiveness. Why on earth would we “have to” strike such a balance? Perhaps you can explain what you think he meant by that.

Because for me, a man who balances honesty and effectiveness is a dishonest man. Perhaps a very effective dishonest man … but a dishonest man nonetheless.

Let me get this straight. I say that when scientists are asked for scenarios, they should provide accurate scenarios rather than scary scenarios. And you’re seriously going to take the other side of that question?

“Offering up scary scenarios” should not be part of anyone’s agenda, mine or yours. (In a curious twist of fate, as I type this, on the TV in the other room they are just advertising “the scariest film you’ll ever see” with lots of cool creepy sound effects, no voiceover, I can’t see the screen … and when they finally get around to announcing the title, it’s “An Inconvenient Truth”. Whoa, be scared, be very scared …)

All that hype is fine if your are a promoter, like Al. It’s not fine if you’re a scientist.

To respond to your question about my honesty, since you have not answered my question about yours, I have attempted always to be as honest as possible in describing the state of climate science, and the amount that we know and don’t know about the climate. Despite Schneider’s claim that for some unknown reason each of us “has to” strike a balance between honesty and effectiveness, we are under absolutely no obligation to make such a Faustian bargain. I strike no balance between honesty and effectiveness, I attempt to exaggerate nothing. I can’t tell if I am being accurate regarding the climate, that knowledge will only come clear after the passing of a decade or so, but I certainly attempt to be.

And yes, I do consider what will happen if others are right and I am wrong. From my perspective, the most probable outcome in that case is that over the next century the world will warm by a few degrees, mostly at night, mostly in the winter, and mostly in the temperate zones. It won’t affect the tropics much. It will likely increase the rain and snow, a warmer world is a wetter world (more evaporation). Me, I don’t see that as a great problem. We’ve warmed something near that much since the 1600s, and it has helped rather than hurt us.

So whether it will warm a degree or two in fifty years is a minor issue on my planet, where we have real problems, huge problems, affecting us today and every day. Given the poverty and wretchedness around the planet, given the lack of clean drinking water, the needless deaths of children from preventable illness, given all the problems that affect us today, I have to say that the scary scenario about how maybe in fifty or a hundred years it will be a few degrees warmer and a bit wetter and the sea level might be 150 mm higher doesn’t rate very high in my assessment of the world’s problems. I live in the third world, I’ve seen worse problems than that all around me for most of my life, grinding poverty and illness and death. That’s the real scary scenario, I make no balance with my honesty when I say that, and we ignore it to debate what may or may not happen in a century at our own peril.

jshore, you are 100% correct when you say you don’t know what was in the CENSORED directory. Let me gently suggest that you find out what was in that directory before adopting such a supercilious tone. Because what you posted, and the study it came from, had nothing to do with what was in the directory. The “sparse network” of the quote you posted was not the Hockeystick network of the CENSORED directory; it was a network starting 400 years earlier, from a different study.

My regards to all,

w.

96

Upon reading my post, I realized that the story of the CENSORED directory might be of interest to some. It’s a bit of a hijack, but as it deals with an icon of the claimed evidence for AGW, it does address the OP. It’s a brief and ugly tale, full of the usual human flaws that sell tabloid newspapers.

In 1998, Dr. Michael Mann, then a rising young climate scientist, was the lead author of a paper purporting to show that if you took a wide range of proxy temperature data (tree rings, ice core data, and the like), the temperature history since 1400 was shaped like a hockey stick. There was a long shaft of level temperatures for hundreds of years, with a blade rising abruptly in the last century or so. Mann, in his capacity as one of the authors of the IPCC Third Annual Report of 2000, inserted it in that report. It soon became a beloved icon of the AGW movement, showing how humans had ruined a climate Eden where the average temperature never changed much.

There was only one problem with the study. Let me say the Hockeystick was built entirely of pine, and then explain what I mean. It was like the perfect storm, where bad math meets bad data.

The “bad math” part, the math error, is now acknowledged by everyone, including Mann. The result of the error was that the procedure actively mined for hockeystick shaped datasets. When it found them, it gave them high weights in the final results, so the output was, voila, a hockeystick.

The bad data is where the CENSORED directory comes in. For the bad math to make a hockystick, it needs hockeystick shaped data to start with. Unfortunately, most of the temperature proxies didn’t have hockeystick shapes.

Curiously, the only proxies that did have that hockeystick shape were tree ring cores of some related species of pine trees found in the American Southwest (bristlecone, foxtail, and limber pines) which collectively are called “stripbark pines”. More curiously, almost every one of the tree ring cores were collected by a man named Graybill, who was trying to show that ring width was increasing because of increasing CO2. This seems to have unconsciously affected his selection of tree ring cores with the hockeystick shape. But I digress, because for whatever reason, unlike almost all the other proxies, they were hockeystick shaped.

So, in the perfect storm, Mann’s hockeystick mining math meets up with Graybill’s hockeystick shaped trees, and a famous hockeystick icon is born.

And eventually, its flaws are discovered, and eventually, it is acknowledged by everyone to have been flawed, and science moves on.

So what’s the big deal?

Well, the big deal is, as was first famously said of US President Nixon regarding the Watergate Breakin, “What did he know, and when did he know it?”.

In the original Hockeystick paper, the authors made the following statement:

Translating from science speak, he says the results are “robust to inclusion”. This means that you can take out some of the proxies, and the results don’t change much. In particular, he says this means that if say some trees have a growth spurt in recent centuries, it doesn’t change the results much whether you include them or not. Thus, “robust to the inclusion of dendroclimatic indicators” means that the results don’t depend too much on some given subset of the data. This "robustness’ is a quality much desired in this type of statistical analysis. It means the conclusions are reliable, that they are scientifically solid.

The way you determine if the data is robust is to pull some of the proxies out of the group, and repeat the calculations without them, and see what the result looks like. You repeat that process a number of times, until you are satisfied that the results don’t change much with different groups of proxies included and excluded.

Again, what’s the big deal? That’s standard science.

Well, the big deal is that Mann knew all along that the hockeystick shape depended entirely and completely on the stripbark pines of American Southwest. That’s what I meant when I said that the Hockeystick was made out of pine. No stripbark pines, no hockeystick, simple as that. Those few proxies are the key to the hockeystick shape.

And to finally get to the initial question, in the directory called CENSORED were the results of one of the studies that Mann did to determine whether the results were robust. These studies were of what happens when the stripbarks were pulled out of the group of proxies. The results did not show the hockeystick shape.

So rather than put those results with the results from the other robustness studies that did show the hockeystick shape, he pulled those results aside, put them in a folder called “CENSORED”, balanced honesty with effectiveness, and published anyway. He knew the whole thing was made of pine. He knew it depended entirely on the inclusion of the stripbark pine data. But he went ahead and not only published the analysis. He also claimed it was robust to the inclusion of various groups of tree ring data, when he had already done (and stowed away) the analysis that showed that claim to be untrue.

Since then, various studies (Wahl and Amman, Mann 2005, etc.) have claimed to resurrect the hockeystick, saying “we’re not repeating Mann’s math error and we still get a hockeystick”. And it’s true, they’re not.

But they haven’t gotten rid of the bad data, data so bad that the NAS panel considering the subject recommended that they not be used. When you use that bad data, even without the use of Mann’s bad math, the bad data ends up with inordinately high weights.

Because of the bad data, all of these papers have ended up claiming that we can tell the Northern Hemisphere temperature hundreds of years ago, to an amazing accuracy, based mostly on the tree rings of a small group of Southwestern semi-desert pine trees … heck, if that’s the case, we can throw away our thermometers and close the ground stations, we’ll just continue to monitor those trees and we’ll know the Northern Hemisphere average temperature. Makes sense to me.

I see this as a perfect example of the folly of the Schneider school of ethics. I’m sure that Dr. Mann is convinced that there is a grave danger from CO2, and that it is vital that he get the message out to people. At the end, he balanced honesty and effectiveness, and honesty lost.

So, that’s the sordid story of the contents of the CENSORED directory. They showed that Mann knew that the Hockeystick was not scientifically valid, that it was not robust, and that he published anyway, including a specific claim of robustness that he knew was false. Truly, a scientific and human tragedy, and a cautionary tale.
My regards to everyone,

w.

97

I wouldn’t call you naive, I would call you driven by an agenda to dislike the man and thus playing “gotcha” where you find in the record something that he says that could be interpretted in a negative light (especially if you avoid what was apparently the surrounding context), take the most uncharitable interpretation of it, and then refuse to believe that he meant anything else.

How much clearer can I be than what I said in the previous post:

In other words:

(1) I reject your interpretation that he was advising people to do this.

(2) I do not follow this “advice” by which I mean your interpretation of his advice, which I believe is not in fact his actual advice.

(3) Rather, I try to follow his advice and his example as he elaborates it in what I linked to, namely:

You know, much scarier to me than someone who admits that one could be presented with a bind that tempts one to do bad things is someone who refuses to admit the possibility that he is tempted to be anything but scrupulously fair and unbiased (unless the record shows that such a person is really so dramatically that way…and I am not sure that I have yet met such a person). One thing that struck me in the recent video of AGW “skeptic” Bob Carter that flex… (forget the exact user name) linked to in a previous thread on AGW is how Carter started out with a claim that he didn’t really have a point-of-view one way of the other (the actual quote was something like, “I am actually agnostic about human caused global warming. I have no axe to grind. Let the facts fall where they may”) and then proceeded to present the most incredibly biased and distorted view of the science that one could. Now, that is scary (or humorous depending on how you look at it).

Sorry, my friend, but I asked you not what will happen if others are wrong and you are right but rather what will happen if others are right and you are wrong. What I see you is making a very slight retreat, i.e., saying, “Well, okay if I am wrong on this little point but I am right on all the rest then…” (By the way, your statement also sort of confuses me since you often seem to imply that you don’t have any idea what the climate sensitivity is given all the large uncertainties that you talk about…It could be 0.5 C or 6 C. And, yet, your statement of being wrong here seems to imply that “being right” would mean it is much closer to the 0.5 C end of things!)

By the way, amidst our discussion back and forth, you may not have noticed my comments to you about Stott et al. in post #90. I’d be curious what you think in light of what I argued from looking at that figure in Stott.

98

Your memory is pretty good - you got most of the way there. :smiley:

99

FYI The latest issue of Skeptic Magazine is on global warming. Shermer was very skeptical of these claims but became convinced by overwhelming evidence.

www.skeptic.com

100

I really wish I had posted the 'Need proof of Global Warming ’ question in the General Questions area and not Great Debates.