NOTE: This has been running two weeks at the top of WUWT, discussion has slowed, so I’m placing it back in regular que. – Anthony
UPDATES:
Statistician William Briggs weighs in here
Eduardo Zorita weighs in here
Anonymous blogger “Deep Climate” weighs in with what he/she calls a “deeply flawed study” here
After a week of being “preoccupied” Real Climate finally breaks radio silence here. It appears to be a prelude to a dismissal with a “wave of the hand”
Supplementary Info now available: All data and code used in this paper are available at the Annals of Applied Statistics supplementary materials website:
http://www.imstat.org/aoas/supplements/default.htm
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Sticky Wicket – phrase, meaning: “A difficult situation”.
Oh, my. There is a new and important study on temperature proxy reconstructions (McShane and Wyner 2010) submitted into the Annals of Applied Statistics and is listed to be published in the next issue. According to Steve McIntyre, this is one of the “top statistical journals”. This paper is a direct and serious rebuttal to the proxy reconstructions of Mann. It seems watertight on the surface, because instead of trying to attack the proxy data quality issues, they assumed the proxy data was accurate for their purpose, then created a bayesian backcast method. Then, using the proxy data, they demonstrate it fails to reproduce the sharp 20th century uptick.
Now, there’s a new look to the familiar “hockey stick”.
Before:
After:
Not only are the results stunning, but the paper is highly readable, written in a sensible style that most laymen can absorb, even if they don’t understand some of the finer points of bayesian and loess filters, or principal components. Not only that, this paper is a confirmation of McIntyre and McKitrick’s work, with a strong nod to Wegman. I highly recommend reading this and distributing this story widely.
Here’s the submitted paper:
(PDF, 2.5 MB. Backup download available here: McShane and Wyner 2010 )
It states in its abstract:
We find that the proxies do not predict temperature significantly better than random series generated independently of temperature. Furthermore, various model specifications that perform similarly at predicting temperature produce extremely different historical backcasts. Finally, the proxies seem unable to forecast the high levels of and sharp run-up in temperature in the 1990s either in-sample or from contiguous holdout blocks, thus casting doubt on their ability to predict such phenomena if in fact they occurred several hundred years ago.
Here are some excerpts from the paper (emphasis in paragraphs mine):
This one shows that M&M hit the mark, because it is independent validation:
In other words, our model performs better when using highly autocorrelated
noise rather than proxies to ”predict” temperature. The real proxies are less predictive than our ”fake” data. While the Lasso generated reconstructions using the proxies are highly statistically significant compared to simple null models, they do not achieve statistical significance against sophisticated null models.
We are not the first to observe this effect. It was shown, in McIntyre
and McKitrick (2005a,c), that random sequences with complex local dependence
structures can predict temperatures. Their approach has been
roundly dismissed in the climate science literature:
To generate ”random” noise series, MM05c apply the full autoregressive structure of the real world proxy series. In this way, they in fact train their stochastic engine with significant (if not dominant) low frequency climate signal rather than purely non-climatic noise and its persistence. [Emphasis in original]
Ammann and Wahl (2007)
…
On the power of the proxy data to actually detect climate change:
This is disturbing: if a model cannot predict the occurrence of a sharp run-up in an out-of-sample block which is contiguous with the insample training set, then it seems highly unlikely that it has power to detect such levels or run-ups in the more distant past. It is even more discouraging when one recalls Figure 15: the model cannot capture the sharp run-up even in-sample. In sum, these results suggest that the ninety-three sequences that comprise the 1,000 year old proxy record simply lack power to detect a sharp increase in temperature. See Footnote 12
Footnote 12:
On the other hand, perhaps our model is unable to detect the high level of and sharp run-up in recent temperatures because anthropogenic factors have, for example, caused a regime change in the relation between temperatures and proxies. While this is certainly a consistent line of reasoning, it is also fraught with peril for, once one admits the possibility of regime changes in the instrumental period, it raises the question of whether such changes exist elsewhere over the past 1,000 years. Furthermore, it implies that up to half of the already short instrumental record is corrupted by anthropogenic factors, thus undermining paleoclimatology as a statistical enterprise.
…
We plot the in-sample portion of this backcast (1850-1998 AD) in Figure 15. Not surprisingly, the model tracks CRU reasonably well because it is in-sample. However, despite the fact that the backcast is both in-sample and initialized with the high true temperatures from 1999 AD and 2000 AD, it still cannot capture either the high level of or the sharp run-up in temperatures of the 1990s. It is substantially biased low. That the model cannot capture run-up even in-sample does not portend well for its ability
to capture similar levels and run-ups if they exist out-of-sample.
…
Conclusion.
Research on multi-proxy temperature reconstructions of the earth’s temperature is now entering its second decade. While the literature is large, there has been very little collaboration with universitylevel, professional statisticians (Wegman et al., 2006; Wegman, 2006). Our paper is an effort to apply some modern statistical methods to these problems. While our results agree with the climate scientists findings in some
respects, our methods of estimating model uncertainty and accuracy are in sharp disagreement.
On the one hand, we conclude unequivocally that the evidence for a ”long-handled” hockey stick (where the shaft of the hockey stick extends to the year 1000 AD) is lacking in the data. The fundamental problem is that there is a limited amount of proxy data which dates back to 1000 AD; what is available is weakly predictive of global annual temperature. Our backcasting methods, which track quite closely the methods applied most recently in Mann (2008) to the same data, are unable to catch the sharp run up in temperatures recorded in the 1990s, even in-sample.
As can be seen in Figure 15, our estimate of the run up in temperature in the 1990s has
a much smaller slope than the actual temperature series. Furthermore, the lower frame of Figure 18 clearly reveals that the proxy model is not at all able to track the high gradient segment. Consequently, the long flat handle of the hockey stick is best understood to be a feature of regression and less a reflection of our knowledge of the truth. Nevertheless, the temperatures of the last few decades have been relatively warm compared to many of the thousand year temperature curves sampled from the posterior distribution of our model.
Our main contribution is our efforts to seriously grapple with the uncertainty involved in paleoclimatological reconstructions. Regression of high dimensional time series is always a complex problem with many traps. In our case, the particular challenges include (i) a short sequence of training data, (ii) more predictors than observations, (iii) a very weak signal, and (iv) response and predictor variables which are both strongly autocorrelated.
The final point is particularly troublesome: since the data is not easily modeled by a simple autoregressive process it follows that the number of truly independent observations (i.e., the effective sample size) may be just too small for accurate reconstruction.
Climate scientists have greatly underestimated the uncertainty of proxy based reconstructions and hence have been overconfident in their models. We have shown that time dependence in the temperature series is sufficiently strong to permit complex sequences of random numbers to forecast out-of-sample reasonably well fairly frequently (see, for example, Figure 9). Furthermore, even proxy based models with approximately the same amount of reconstructive skill (Figures 11,12, and 13), produce strikingly dissimilar historical backcasts: some of these look like hockey sticks but most do not (Figure 14).
Natural climate variability is not well understood and is probably quite large. It is not clear that the proxies currently used to predict temperature are even predictive of it at the scale of several decades let alone over many centuries. Nonetheless, paleoclimatoligical reconstructions constitute only one source of evidence in the AGW debate. Our work stands entirely on the shoulders of those environmental scientists who labored untold years to assemble the vast network of natural proxies. Although we assume the reliability of their data for our purposes here, there still remains a considerable number of outstanding questions that can only be answered with a free and open inquiry and a great deal of replication.
===============================================================
Commenters on WUWT report that Tamino and Romm are deleting comments even mentioning this paper on their blog comment forum. Their refusal to even acknowledge it tells you it has squarely hit the target, and the fat lady has sung – loudly.
(h/t to WUWT reader “thechuckr”)
The CO2 increase compared to the total atmosphere is indeed very small, and it is fun to educate uninformed people to this fact because it isn’t exactly the impression you get from the MSM. But other than a smart talking point it is in fact a non-argument since it is the physical and chemical properties that are interesting and not what your gut feeling tells you is a minuscule change — if 1/10000 of my body changed to plutonium I wouldn’t be in good shape for long. Even Monckton agrees that the CO2 gives about 1K warming per century (assuming zero feedback), so even the tiny amount does have a surprisingly big influence.
pax: August 28, 2010 at 10:30 am
But other than a smart talking point it is in fact a non-argument since it is the physical and chemical properties that are interesting and not what your gut feeling tells you is a minuscule change — if 1/10000 of my body changed to plutonium I wouldn’t be in good shape for long.
Depends on which isotope of plutonium and which 1/10,000 of your body mass changed.
If it was Pu-233, within 20 minutes you’d have to worry more about lead poisoning than cancer.
Henry @ur momisugly Walter Schneider
Thanks for that observation. I missed that. The experiment shows that CO2 also absorbs visible light. Never too old to learn something new. Thus, the experiment proves that CO2 is cooling the atmosphere. Like I have been telling here before when I saw that CO2 radiation coming back from the moon!
Henry @ur momisugly Pax
Even if Monckton agrees that the CO2 gives about 1K warming per century he would still have to prove this (to me, to us, at any rate). We need to see actual tests & experiments that prove that the net effect of CO2 is warming rather than cooling and the experiment’s results must also give us a clear correlation as to quantities as well, i.e. that an increase of 0,02% w/w in the concentration of CO2 would cause an increase of 1K/100yrs.
The way I understood Monckton, is that he always said: Even if, …etc… it would not be worth spending the money trying to prevent it…. etc. etc. But maybe I am wrong?
Blessings,
ool
Comparisons with the effect of certain chemicals on organisms are not apt, if only because all those things can be empirically observed before they are theoretically explained (if and when they can be explained). There are thousands of experiments documenting the effect of different CO2 concentrations on different organisms, but none documenting its warming effect on the planet. Some things that are very well understood can be reliably calculated. Many other things can’t. If a pharmaceutical company insisted on selling untested drugs, advancing the argument that their effects on our organism had been theoretically calculated by their in-house chemists, and therefore testing was unnecessary or unpractical, I doubt you would be too comfortable with those kinds of arguments. As I have been saying, I know of no empirical tests trying to document the warming effect of an increase in atmospheric CO2 that so far amounts to 0.0001 of the atmosphere. You might think that devising and carrying out such experiments would be considered worthwhile, given the enormous importance this issue has acquired. And yet, we seem to be forever mired in endless theoretical arguments whose results range from concluding there is a negligible effect per doubling of CO2, to as much as 7 deg C per doubling, depending on how the calculating melody is arranged.
Such wild discrepancy of results does not inspire much confidence in our ability to calculate this effect theoretically. If, for example, a group of drunken surveyors told you they calculated the height of a tree by trigonometry, and found it to be anywhere between 30 and 180 meters, it might be more practical to stop listening to them and, instead, send someone up the tree with a measuring tape (someone sober, that is), unpractical though the climbing it may be.
And let’s not even get into the topic of trying to calculate the effect on temperature that we may expect from establishing certain schemes such as carbon trading and Kyoto-like accords. That’s too bizarre to get into.
The CAGW doctrine and its solutions are without doubt one of the biggest mass delusions ever dreamed up by humans. Things such as the tulip craze, the weirdest theological arguments of the past, phrenology, the lobotomy fashion, etc., are a picnic in the park by comparison.
Henry Pool says:
August 28, 2010 at 12:38 pm
“Henry @ur momisugly Walter Schneider
Thanks for that observation. I missed that. The experiment shows that CO2 also absorbs visible light. Never too old to learn something new. Thus, the experiment proves that CO2 is cooling the atmosphere. Like I have been telling here before when I saw that CO2 radiation coming back from the moon!”
Henry, that is not quite what I saw in the experiment or what I described.
The experiment proves very little, if anything. At best (provided one believes all of the unsupported assertions by the narrator), the experiment proves that CO2 filters out visible light and causes the global surface to get darker. (I don’t believe that the image produced by the camera is an IR image. The colour scale is too similar to what the video camera shows for the candle flame.)
The narrator asserts that the absorbed visible light heats the atmosphere, for which he shows absolutely no evidence, while his experiment shows that there is less visible light impacting on the global surface. Still, that conclusion would be valid even if the image produced on the LCD screen is a correct representation of the candle’s IR image, and if one were to substitute IR for visible light. In that case the global surface would become substantially cooler, not just darker.
My impression is that the narrator is wrong about what he is talking about. He claims that he “proves” that CO2 cools the global surface and that the missing energy gets stuck in the atmosphere. It would logically follow that the more light is absorbed by CO2, the more the atmosphere heats up…and then we will all die!
When I went to school, a Grade VI student would have been able to point out the errors of the narrator’s ways. The narrator might have said, “Look! You can feel the plexi-glass tube is heating up, which proves the atmosphere is getting hotter,” while the student would have said, “You are right about the heat, but if I can feel the heat on the outside of the tube, then that means that it is escaping from the atmosphere. Is it not going into space?” Upon which the narrator might have left the classroom to find some help.
In the youtube experiment, the narrator has no one who performs that sort of quality control on his work. He just makes unsubstantiated assertions that go unchecked, which is, as far as I can see as of now, true of the assertions that promote the CAGW hype and hysteria. Lack of quality control is a killer; and peer review is a poor substitute.
@Walter Shneider
“The experiment proves very little, if anything. At best (provided one believes all of the unsupported assertions by the narrator), the experiment proves that CO2 filters out visible light and causes the global surface to get darker. (I don’t believe that the image produced by the camera is an IR image. The colour scale is too similar to what the video camera shows for the candle flame.)”
I agree that the experiment proves very little, but you are quite wrong when you infer that the CO2 is filtering out visible light. It is an IR camera as stated in the video with the tonality set for best dramatic effect. CO2 is transparent to the visible light wavebands.
Henry @ur momisugly Walter/ Paul
I checked again just to make double sure. There are indeed no absorptions of CO2 in the visible light area (from 0.4 to 0.7 um). There are absorptions in the infra red area namely 1.4 -1.5 um, 1,6 um (2 peaks), and at ca. 2 um (3 large peaks). There are also a few absorptions noted in the UV area, namely
there is absorption of CO2 at between 0.21 and 0.19 um (close to 202 nm):
and at between 0.18 and 0.135 um and between 0.125 and 0.12 um.
We already know from the normal IR spectra that CO2 has (very)big absorption between 4 and 5 um. Ths sun is shining between 0 and 5 um, 12 hours per day.
So you have to weigh the above cooling against the warming by trapping earthshine at between 14-15 um (24 hours per day)
Anyone care to place bets?
Paul_K says:
August 28, 2010 at 8:52 pm
@Walter Shneider
“I agree that the experiment proves very little, but you are quite wrong when you infer that the CO2 is filtering out visible light. It is an IR camera as stated in the video with the tonality set for best dramatic effect. CO2 is transparent to the visible light wavebands.”
Thanks, but then the conclusion drawn by the narrator is still wrong or quite misleading, even though only IR is involved. According to the experiment, the global surface would be cooling, and the conclusion states that all of the heat energy is trapped in the atmosphere.
Aw gawd, not Mann. Cue the Climatists with their NASA, Government and “experts” cut and pastes.
Did everybody miss this? http://www.express.co.uk/posts/view/162506/How-carbon-gases-have-saved-us-from-a-new-ice-age-
In a talk at London’s Science Museum (March 10 2010) Dr Lovelock said the balance of nature was in charge of the environment.
He said: “We’re just fiddling around. It is worth thinking that what we are doing in creating all these carbon emissions, far from being something frightful, is stopping the onset of a new ice age. “If we hadn’t appeared on the earth, it would be due to go through another ice age and we can look at our part as holding that up. “I hate all this business about feeling guilty about what we’re doing. “We’re not guilty, we never intended to pump CO2 into the atmosphere, it’s just something we did.”
Paul_K: August 28, 2010 at 8:52 pm
I agree that the experiment proves very little, but you are quite wrong when you infer that the CO2 is filtering out visible light. It is an IR camera as stated in the video with the tonality set for best dramatic effect. CO2 is transparent to the visible light wavebands.
The glass end caps would have to be made with some material which is transparent to IR — given the reddish tint, I’d guess gallium arsenide — but since the candle is being filmed through a closed tube while the CO2 is being introduced, the experiment is actually demonstrating the *cooling* effect of the expanding CO2 as it’s entering the tube.
Francisco says:
“You might think that devising and carrying out such experiments would be considered worthwhile, given the enormous importance this issue has acquired”.
Henry@Francisco
Truly amazing yes!!
ANYBODY thought that EVERYBODY could do it. EVERYBODY thought that SOMEBODY would do it. In the end, NOBODY did it!!
When I asked Shell for the results, I got the answer that they decided to go mainstream i.e. that the “science” was settled. They sent me some stuff from Weart. (an historian, who has no scientific knowledge whatsoever)
Nobody has done any real research. It all just stories, incorrect formulae and “calculations.” No actual measurements.
In the meantime, perhaps the the CO2 is cooling more than it is warming? We could be heading for global cooling/Who knows what we find out one day.
What I don’t understand: why doesn’t anyone just sue the oil companies for the (correct) results, i.e.
how much warming and how much cooling is caused by the CO2 in W/M3 0.03-0.06%/m2/24 hours?
BillTuttle says:….which is transparent to IR — given the reddish tint, I’d guess gallium arsenide — but since the candle is being filmed through a closed tube while the CO2 is being introduced, the experiment is actually demonstrating the *cooling* effect of the expanding CO2 as it’s entering the tube.
Amazing, the talent we have here!!!
Henry Pool: August 29, 2010 at 5:40 am
Amazing, the talent we have here!!!
Well, thank you, but it’s not talent, just a few years’ experience with — ummmmmm — helicopter “target acquisition and engagement” systems.
AntonyIndia says:
August 29, 2010 at 1:34 am
“Did everybody miss this? http://www.express.co.uk/posts/view/162506/How-carbon-gases-have-saved-us-from-a-new-ice-age-”
–
Thanks AntonyIndia . I am so impressed with Dr. Lovelock’s recent turnaround. Now that shows a true scientist that can realize the data and consensus is not supporting his views, becomes skeptical of himself, and change.
Some recent quotes of Dr. Lovelock:
“We’re just fiddling around. It is worth thinking that what we are doing in creating all these carbon emissions, far from being something frightful, is stopping the onset of a new ice age.
“If we hadn’t appeared on the earth, it would be due to go through another ice age and we can look at our part as holding that up.”
“I hate all this business about feeling guilty about what we’re doing.”
“We’re not guilty, we never intended to pump CO2 into the atmosphere, it’s just something we did.”
He compared the recent controversy to the “wildly inaccurate” early work on aerosol gases and their alleged role in depletion of the ozone layer.
“Quite often, observations done by hand are accurate but all the theoretical stuff in between tends to be very dodgy and I think they are seeing this with climate change. We haven’t learned the lessons of the ozone-hole debate. It’s important to know just how much you have got to be careful.”
Read the story above and research his recent turnaround. I’m impressed with you Dr. Lovelock. There is a scientist.
Hi Bill,
“The glass end caps would have to be made with some material which is transparent to IR — given the reddish tint, I’d guess gallium arsenide — but since the candle is being filmed through a closed tube while the CO2 is being introduced, the experiment is actually demonstrating the *cooling* effect of the expanding CO2 as it’s entering the tube.”
For a moment there I thought you were smoking the same stuff as Henry, but then I realised you were talking about a possible Joule-Thomson effect. Instead of trying to overanalyse or fix it, why don’t we all just agree that the whole experiment is completely irrelevant in terms of empirical proof of AGW?
Hi Henry (Pool),
Henry, some of your comments are so bad, they are not even wrong. You are in danger of giving scepticism a bad name. I have not seen so many junk science assertions since the last time I visited RC. You really do need to bone up on some basic science, man. Try the Science of Doom site for a non-fanatical review of basic physics. I am not going to engage you on the various assertions you have made in this thread since (1) they are way O/T and (2) I don’t know how much longer I have to live. Put some effort into understanding what has been tested and then question what hasn’t!
Here is more of Lovelock on that same day in March 2010: http://www.timesonline.co.uk/tol/comment/columnists/guest_contributors/article7061020.ece
“I think you have to accept that the sceptics have kept us sane — some of them, anyway,” he said. “They have been a breath of fresh air. They have kept us from regarding the science of climate change as a religion. It had gone too far that way. There is a role for sceptics in science. They shouldn’t be brushed aside. It is clear that the angel side wasn’t without sin.”
Lovelock places great emphasis on proof. The climate change projections by the Meteorological Office’s Hadley Centre — a key contributor to the IPCC consensus — should be taken seriously, he said. But he is concerned that the projections are relying on computer models based primarily on atmospheric physics, because models of that kind have let us down before. Similar models, for example, failed to detect the hole in the ozone layer;
How should we be spending our money to prevent possible disaster? In Britain, says Lovelock, we need sea walls and more nuclear power.
“What would you bet will happen this century?” a mathematician asked him. Lovelock predicted a temperature rise in the middle range of current projections — about 1C-2C — which we could live with. Ah, but hadn’t he also said there was a chance that temperature rises could threaten human civilisation within the lifetime of our grandchildren? He had. In the end, his message was that we should have more respect for uncertainties and learn to live with possibilities rather than striving for the 95% probabilities that climate scientists have been trying to provide. We don’t know what’s going to happen and we don’t know if we can avert disaster — although we should try. His sage advice: enjoy life while you can.
Antony India, thanx for the Lovelock piece. Absolutely brilliant!
Real Climate comments on this are an absolute hoot. The general theme is, “We haven’t really had a chance to go through this — indeed, most of us don’t understand it in the slightest — but let us shrug it off as irrelevant and/or cast espersions on it nonetheless.”
Who says they aren’t about predictability and replication over there?
Some there are already in full smear mode, too: One frequently commenting True Believer going by the name of dhogaza dismisses McShane and Wyner as “some b-school profs,” a post to which an editor there going b y “Jim” responds beginning with, “Thank you.”
duckster said:
Many thanks for providing the follow-up links on reactions to McShane and Wyner. William Briggs’ observation is particularly stunning: Considering all of the uncertainties in a Bayesian model of predicted temperatures, one can draw a big, fat, yellow line from year 1000 to 2000 — an absolute flatline in temps! — that fits within the model and range of uncertainties as well as Mann and the gang’s super-tricked-out attempt.
Or as Briggs puts it: “This is just as beautiful as a shorthanded goal. It means we cannot tell—using these data and this model—with any reasonable certainty if temperatures have changed plus or minus 1 degree C over the last thousand years.”
That some are attempting to spin this by focusing on its possible ramifications for the MWP … well, they’d already confirmed a long time ago that they have no shortage of chutzpah.
Paul_K says:
August 29, 2010 at 2:51 pm
……”Hi Henry (Pool),
Henry, some of your comments are so bad, they are not even wrong.”……
Paul instead of pointing to lets say the worst of Henry’s so called “wrong comments” you simply attack the person.
You sound like a visitor from Deltoid.
Exchanges here at WUWT have been characteristically informative and good natured.
Henry’s main point as I understand it is to question the balance of CO2 cooling particularly above the troposphere with any heating in the lower troposphere.
He asked for “experimental evidence” rather than “calculations “, whats so wrong in that?
By the way Science of Doom are not too hot on experimental evidence!
Lovelock: “There is a role for sceptics in science.”
The actual point is: if the Scientific Method is properly employed, scepticism is already built into science as a most obviously integral feature of science itself. That’s the whole point of the requirement that the “materials and methods” involved in a study be made easily available for anyone who so desires to look at and try to critique.
So there simply is not any doubt at all about the necessity of scepticisim in science. Moreover, at an even earlier stage of doing science, the authors of a study should have already been trying to find fault with their own study.
Thanks, Bryan
You say: “Henry’s main point as I understand it is to question the balance of CO2 cooling particularly above the troposphere with any heating in the lower troposphere.”
True. But why do you think the cooling is more happening on top and the warming more below? The radiation (from the sun or from earth) hits on the molecule whereever it is in the way, gets absorbed and is then re-radiated. Because of the random position 50% of this re-radiation is send back in the direction where it came from causing said cooling or warming effect. Is the way from the bottom to the top (for earthshine) not the same as from the top the bottom (for sunshine)?
(I hope this is not a stupid question – but I do need to get some clarity on this)