Guest Post by Willis Eschenbach
The quote above is from Lord of the Rings, an exchange between Gollum and Smeagol, and it encapsulates my latest results from looking into the Shakun 2012 paper, “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation” (paywalled, at Nature hereinafter Shakun2012). I discussed the paper in my post “Dr. Munchausen Explains Science By Proxy“. Please see that post for the underlying concepts and citations.
When I left off in that post of mine, I had investigated each of the 80 proxies used in Shakun2012. I plotted them all, and I compared them to the CO2 record used in their paper. I showed there was no way that the proxies could support the title of the paper. Figure 1 recaps that result, showing the difficulty of establishing whether CO2 leads or lags the warming.
Figure 1. All proxies (green dots) from Shakun2012 (Excel spreadsheet). CO2 values digitized from Shakun 2012 Figure 1a. There is pretty good agreement between the warming and the changes in CO2.
Note that the proxies say the earth generally warmed from the last ice age, starting somewhere about 15,000 BC, and the warming lasted until about 9,000 BC. Since then, the proxies have the greatest agreement (darkest green). They say that the globe generally cooled over the length of the Holocene, the current interglacial period since the last ice age.
Today I was thinking about that single record that they used for the CO2 changes. I got to wondering what other ice core CO2 records might show about the change in CO2. So I went and downloaded every ice core CO2 record that I could find that covered the time period 26,000 BC to modern times. I found a number of ice core records that cover the period.
Then I collated all of them in Excel, saved them as a CSV file, opened the file in R, and plotted every ice core CO2 record that covered the record from 26,000 BC up to the present. I standardized them over the same period covered by the Shakun2012 CO2 data. There was excellent agreement between the Shakun2012 data and the ice core records I had downloaded … but there was also a surprise.
Figure 2 shows the surprise …
Figure 2. As in Figure 1. Black circles show Shakun2012 CO2. Additional colored dots show the ice core CO2 records which have data from 26,000 BC to the present.
Dang, I didn’t expect that rise in CO2 that started about 6,000 BC. I do love climate science, it always surprises me … but the big surprise was not what the ice core records showed. It was what the Shakun2012 authors didn’t show.
I’m sure you can see just what those bad-boy scientists have done. Look how they have cut the modern end of the ice core CO2 record short, right at the time when CO2 started to rise again …
I leave the readers to consider the fact that for most of the Holocene, eight centuries millennia or so, half a dozen different ice core records say that CO2 levels were rising pretty fast by geological standards … and despite that, the temperatures have been dropping over the last eight millennia …
And I leave everyone to ponder how far climate “science” has fallen, that a tricksy study of this nature can be published in Nature, and can get touted around the world as being strong support for the AGW hypothesis. The only thing this study supports is the need for better peer review, and at a more basic level, better science education.
My best to all, stay skeptical,
w.
Source data:
ICE CORE CO2 DATA: All ice core CO2 data are from the NOAA Paleoclimatology site, the “Ice Core Gateway” page, in the section “Gases”.
[UPDATE] A hat tip to Jostein, in the comments he points out that the original Shakun Nature paper is here (pdf).
RockyRoad says:
April 8, 2012 at 5:35 pm
“Eric Adler says:
April 8, 2012 at 4:22 pm
[…] So the current change in CO2 represents a comparable forcing factor to the deglaciation.
Maybe we should work on tripling the CO2 contribution to the atmosphere, then, so the temperatures will actually go UP instead of declining.
That, or your hypothesis is incorrect.”
Your ignorance of climate science is showing. You seem to be referring to the recent slowdown in global warming. It is well understood that internal variation during such a period can overcome the global warming trend due the GHG’s. In addition sulfate aerosals, which have a short lifetime in the atmosphere are believed to exert a cooling influence. This will be transitory.
Global warming due to any forcing has a built-in delay due to the vast heat capacity of the earth. With such a rapid ramp up of CO2, the increase in surface temperature will certainly be delayed by a large amount. Ah, the nasty ad hom, eh? It very well could be that you’re conveniently forgetting the earth has been warming since the LIA, most of which warming came about with little or no benefit of anthropogenic CO2. Or was this past warming (according to some “Back to the Future” CAGW thinking), magically due to the higher levels of CO2 we’re seeing now?
You concentrate on one miniscule point which I didn’t make and fail to see the bigger picture. (I love setting traps, Eric; you’ve been caught).
So I shall repeat: “That, or your hypothesis is incorrect.”
wmconnolley says:
April 8, 2012 at 12:48 am
So explain to me, wm, how a 200-yr dispersion shift in CO2 somehow erases a 600- to 800-yr temperature shift in the ice cores?
Talk about “wandering off”.
Most of us can do rudimentary math, wm.
Nick Stokes
This is science not political word games. If there is data at hand that confirms or calls into question the basic underlying arguments surely it sould be presented. But I guess a little bit of doubt doesn’t get you into Nature.
I think I can thoroughly dispell Willis’ denialists whining with a simple quote from Einstien:
(paraphrased so I don’t have to go look it up, ’cause we don’t look stuff up when we talk about climate, don’t you know.)
From Einstien:
“Countless exceptions to the theory of relativity may indicate that I am wrong, but if I can get enough examples of cases where observations match my theory into the news, then people will believe me anyway.”
Well, that’s paraphrased, but it’s close enough for Team Nature.
That was a joke, of course. On the serious side, my above fake “quote” seems to a strategy that works for just about any cause you can name. Special interest groups use that tactic with brutal effectiveness every day. Too bad there’s not a special interest group who looks out for America’s #1 endangered species: middle class working families (not sure what the Latin for that is).
LazyTeenager says:
April 9, 2012 at 4:52 am
“All of these changes in CO2 and temperature are occurring before human civilization started. Which means that there is no anthropogenic CO2 to speak of over this period. Which means there is no AGW prediction that during these prehistoric periods CO2 increases will preceded temperature rises.
In fact the prediction is the opposite. Solar Insolation charges cause temperature rises which cause CO2 rises which in turn amplify the temperature rise in positive feedback. AGW theory has it that temperature rises are expected to precede CO2 rises in the post ice sheet time frame.
This paper contradicts that theoretical expectation.”
In fact it does not contradict it. Temperature rises in the Southern Hemisphere did precede the rise in CO2, and further increases in global temperature resulted from that. The author says:
“These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.”
Nick Stokes’ point is entirely valid. The title of the paper does in fact represent what they observed in the data for the period they chose.
But the title does not properly represent the authors’ (and the craven warmist media’s) attempt to argue their specific time-slice represents the general case.
Eric Adler says:
April 9, 2012 at 7:10 am
LazyTeenager says:
April 9, 2012 at 4:52 am
It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.
The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?
Yet another Nature trick…
RockyRoad says:
April 9, 2012 at 6:04 am
“You concentrate on one miniscule point which I didn’t make and fail to see the bigger picture. (I love setting traps, Eric; you’ve been caught).
So I shall repeat: “That, or your hypothesis is incorrect.””
Crowing about your own brilliance is silly. Your point was that currently the earth is not warming.
That is a common argument used by so called “skeptics”, has been answered over and over again, and represents a failure on your part to look at the bigger picture.
[SNIP: Eric, if you have an argument, make it here. We are not directing traffic to an unreliable web site. -REP]
From Pat Frank on April 8, 2012 at 2:38 am
Isn’t the square root of the square just the number?
Cumulative summing of errors is known in machining, for example. If you have a line of four holes with a tolerance of +/-0.005″ on the spacing between the holes, then 3 spaces times +/-0.005 yields possible positional error between first and last holes of +/-0.015″. Likewise when items of known length tolerances are stacked when figuring out overall length, be it measuring standards for reference or parts in an assembly.
Although there can be an assumption of greater accuracy. For example, if it is assumed the measurements will fall at the middle of the tolerance, then the probability of summed measurements being at the middle of the summed tolerances grows. If the machinist was to be trying to hold +/-0.002″ on three measurements of +/-0.005″, as normally you stay away from the limits, then it is probable that the sum of the measurements is around +/-0.006. You might be able to argue it is likely better than that, as you could have two measurements on the positive and one on the negative which cancels out some error, and it is more likely for three to have two on one side and one on the other than all three on one side, etc.
In reality smart engineers and draftsmen know better than to assume and specify the overall accuracy as absolutely required. It fits or it doesn’t, assuming it probably will doesn’t work. But in a fuzzy wishy-washy field like Climate Science™ when backed with the pliant statistics of probability, I can see how they can claim greater accuracy.
Latent heat. When ice is melting, the temperature doesn’t rise.
Is a good amount of CO2 released when ice melts?
phlogiston says:
April 9, 2012 at 9:47 am
“Eric Adler says:
April 9, 2012 at 7:10 am
LazyTeenager says:
April 9, 2012 at 4:52 am
It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.
The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?”
If you look at the temperature curves in figure 2a of Shakun’s paper, you see that the Younger Dryas event did not hit both hemispheres in the same way. The Southern Hemisphere temperature started to decline while the Northern Hemispere was rising and vice versa as time proceeded. So the average global temperature plateued, as did the CO2 concentration, between 15KyBP and 13KyBP. So if you look carefully, your objection disappears.
http://sciences.blogs.liberation.fr/files/shakun-et-al.pdf
The major point made by Shakun2012 is that temperature changes in the Northern and Southern hemispheres are offset, so that the lag between global average temperature and CO2 is less than the 800 year lag between Antarctic temperature and CO2. Simulations show that CO2 was driving the temperature increase during that periond. The behavior of global average temperature and CO2 during the Younger Dryas does not contradict that point.
Phlogiston says:
“However the elephant in the room here is the Younger Dryas (YD). As commented above, during the YD temperatures fell (as shown by the ice cores and better proxies) but CO2 did not. To anyone genuinely interested in reasons for global temperature change and with an open mind as to the role of CO2, this YD observation should be of huge interest as an important clue.”
You are wrong. Global Temperatures and CO2 plateaued. The temperature changes see sawed between the two hemispheres during the Younger Dryas. Check the fig 2a of Shakun’s paper.
REPLY: LOL! Just because Shakun says so in one paper doesn’t make it true, unless of course you are an unquestioning true believer like Mr. Adler – Anthony
Philip Bradley (and others) complained that my link (http://scienceblogs.com/stoat/2007/03/yet_more_tco2_lags.php) starts with text clearly contradicted by what WE has shown here. First, thanks for reading, and pointing out the apparent problem. EWW is a scientist, not a lawyer. I’ve updated the text into a form that should make you happy.
Second, and more important, we don’t have a global temperature record for the holocene, so the claims here of CO2 up while T goes down are premature. CO2 goes up (a little bit) and we know that is global, so that is fine. But a scatter plot of proxies smoothed by eye is not a temperature record, so you fail on the “T goes down bit”. AFAIK there is no recognised global (or hemispheric) temperature record for the holocene, or for the last 6 kyr. If you think you have one, and can justify it, that would be publishable.
That leaves two things: the people calling WE’s post “brilliant” and pressing him to publish it; and those calling on Nature to retract Shakun because of it. The latter is nonsense, as NS has already said: this post doesn’t contradict Shakun. The former is badly out of touch with reality: all WE has done here is draw the CO2 record (which is already well known) and created something that looks to amateur eyes as though it could be a temperature record. But there is no way you could get that past real journal review.
(And failing to mention Ruddiman is odd, too).
I would confront the author of the study with your findings, Willis, and ask him to withdraw or repair/amend his paper, before writing a comment to Nature. But that’s only the way we would handle errors in software development if the review-process hasn’t found them. I’m not sure, wether this is correct in science as well……
Stephen says:
April 9, 2012 at 1:58 pm
A number of folks have suggested I write up a comment for Nature regarding this study. You suggest I write the author and write to Nature. I likely won’t do either one, for several reasons.
The first is that writing scientific papers is a pain in the fundamental orifice. If I’m going to do it, I’ll do it for some independent scientific analysis that I’ve done. For me, it’s not worth doing just to falsify someone else’s work. I’ve done that in the past, but now I have other interests.
The second is that most of the scientific players who would read such a “Communications Arising” in Nature read WUWT as a part of their daily fare. If you are a serious player in the climate game, you read WUWT, and Climate Audit. Even the avid AGW supporters read WUWT and Climate Audit, just to stay ahead of what the opposition is saying.
The third is, I’m not writing for history. I’m not writing to establish my scientific credentials. I don’t have to publish or perish. I write in order to influence the ongoing scientific dialog, and that dialog has moved and is moving even further onto the web. From my own experience with “Communications Arising” in Nature, it takes some months before my study would appear … and by then, the scientific discussion has moved way beyond whatever my study was about.
The fourth is eyeballs. My work on WUWT draws about a million page views per year.
Now, this doesn’t mean that I don’t want to publish in the journals. I do. There’s three or four things I would love to see published. My cluster analysis of the Mann proxies. My analysis of the tropical tropospheric hot spot. My work with the TAO buoys. My investigation of the maximum ocean temperature through the Argo floats. All of those are valuable, valid original scientific work.
But just for dis-assembling shabby science like this? Not worth the effort to get it published, for me. If someone wanted to work with me to get a “Communications Arising” published in Nature, I’d work with them, but to do it myself is not worth it.
w.
wmconnolley says:
April 9, 2012 at 1:42 pm
What I have is eighty proxies that go down over the Holocene by about a degree or so. I know you don’t like that, but there it is. Claiming that they are “smoothed by eye” is nonsense, they are not smoothed at all. They are standardized and displayed. Period.
Do those 80 proxies comprise a “global (or hemispheric) temperature record”? Well, the authors of Shakun2012 argue very strongly that it is both, so you’ll have to take that up with them …
w.
Thank you for your quick answer, Willis. I understand and respect your reasons. All I wanted to ask for, was to drop the link of this thread into the authors mailbox, that should be enough, since you published your work here…..I hope I find the time to read your love-to-be-published studies!
From wmconnolley on April 9, 2012 at 1:42 pm:
Google cache of original (March 18 2012):
Updated:
Something falsifiable and absolute was stated back in 2007, Willis Eschenbach falsified it, so you “updated” it to remove the inconvenient falsifiable-ness.
By the terms originally posited five years ago, that you posted on your blog without objection, Willis Eschenbach has conclusively demonstrated that your knowledge of the greenhouse effect must be faulty. So now you “update” those terms with additional weaselly-ness (as appropriate for a stoat), and proclaim ‘Ah-ha, it didn’t happen, Eschenbach hasn’t proven anything!’
Wow. So now in addition to Mike’s Nature trick, we have Connolley’s “As true as it ever was!” trick. So noted, so remembered.
kadaka,
Thank you for pointing out that Willy is as ethics-challenged as Peter Gleick. IMO neither one is honest. An honest man would have admitted his error, or at the very least, kept quiet. But as the Wikipedia Chief Propagandist, Connolley is used to altering the record. His self-identity as a weasel is appropriate.
phlogiston says:
April 9, 2012 at 9:47 am
“It is not the south-north hemispheric see-sawing that is the only – or the most important – complicating factor here. It is the Younger Dryas. This results in not one but two large temperature increases from essentially glacial to interglacial temperature. The army of proxies, biological and other, showing the temperature rise are conveniently smeared out over a longer time by these two upslopes. Combine this with the fact that CO2 did not decrease during the Younger Dryas, and you get the ingredients for statistical prestidigitation to show the appearance of CO2 presaging temperature.”
If you look at figure 2a in the Shakun paper, during the Younger Dryas, the temperature drops were not simulataneuos in the 2 Hemispheres. As a result The global temperature did not drop; during the Younger Dryas, it stayed constant during this period. This is simple to see from the graph by taking the average of the two hemispherical temperatures.
The 80 proxies representing different regions of the earth do not behave simultaneously. They should not be expected to. The ocean currents are constantly shifting. Your adjective convenient has absolutely no meaning here. Proxies do not understand the concept of convenience. Proxies are not humans.engaging in a conspiracy to deceive global warming skeptics.
You wrote further,
“The conclusion drawn in MSM commentaries is that this strengthens the evidence for the controlling role of CO2 in driving temps. If this is the case – why did CO2 not decrease during the Younger Dryas?”
It is clear from your reply that you didn’t follow, or care to follow, my answer to this question, and are asking it again. Your objection seems to be that the proxies are engaged in a conspiracy to deceive global warming skeptics. Are you for real?
phlogiston,
As Anthony correctly pointed out, Adler is an unquestioning true believer. Adler is also wrong. He tries to claim that because hemispherical temperature variability is not simultaneous, Shakur et al. remains unfalsified.
But that is a strawman argument. As we see here, global temperatures never occur in lock step [lower chart]. But we do see that global temperature variability is highly correlated between the hemispheres.
Willis has done an outstanding job of deconstructing the shaky Shakur paper in his series of articles. Obviously Shakur et al. was simply hand-waved through pal review without the least bit of scrutiny. It is an ugly turn of affairs when once reputable journals become politicized pseudo-science enablers, but that is in fact what has happened. The result is that fatally flawed papers give mindless cheerleaders and alarmist lemmings something to rally around, as we see above. And true to form, they totally ignore the scientific method.
Adler fits the description of Orwell’s Winston Smith, who wonders: if enough people believe that 2 + 2 = 5, does that make it true? Believing in Shakur et al. does not make it true, and in fact most research papers are false. Shakur is in the majority there.
Wmconnolley says:
“Second, and more important, we don’t have a global temperature record for the holocene, so
the claims here of CO2 up while T goes down are premature. CO2 goes up (a little bit) and we know that is global, so that is fine. But a scatter plot of proxies smoothed by eye is not a temperature record, so you fail on the “T goes down bit”. AFAIK there is no recognised global (or hemispheric) temperature record for the holocene, or for the last 6 kyr. If you think you have one, and can justify it, that would be publishable.”
I have seen graphs of average global temperature during the holocene period. It seems there have been a number of different reconstructions; and the temperature does seem to go down a bit since 7500yBP. It does appear that there is a lot of disagreement among the different reconstructions regarding details so it does seem that a solid new reconstruction would be well worth a publication.
http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png
In a previous post, I pointed out that the rise in CO2 is only about 8%, and the forcing from it would be small. If the standard estimates of climate sensitivity, 3C are correct, CO2 by itself , would increase global average temperature by about 0.3C. During this time period, the orbital and axial forcing is acting to reduce global temperatures. The actual drop in global temperatures appears to be a few tenths of a degree C. This is small compared with the 3.5 C rise in temperature during the period of deglaciation, which is obviously a lot easire to model. In fact, CO2 during that period of time increased by 86% which is almost a doubling, so this is consistent with the most common estimate of climate sensitivity.
Smokey,
“Adler fits the description of Orwell’s Winston Smith, who wonders: if enough people believe that 2 + 2 = 5, does that make it true? Believing in Shakur et al. does not make it true, and in fact most research papers are false. Shakur is in the majority there.”
[snip] One could just as well argue that Eschenbach’s critique is one of the majority of papers which are wrong!
REPLY: Tsk, language Mr. Adler – Anthony
Adler says:
“As usual, your argument is crap.”
As usual, your comment is only your baseless opinion. I give specific details, along with citations. Night and day.