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).
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Great work Willis.
I wonder if the Shakun 2012 CO2 source data did have values for the period between 5000 BC and the present? As you say it is not included in their spreadsheet. If so then it’s hard to imagine any legitimate argument to justify omitting that period. Other than the bleeding obvious of course.
Sounding more and more like yet another team effort?
To paraphrase Prof Jones: “I’ve just completed an alike Nature trick of not adding CO2 proxies to the proxy temps for the last 500 years to hide the incline.”
Classic piece of research checking to ask the question ‘what was left out and why ‘ , its one of those idea that should be taught to any undergraduate. Its failure to occur in this paper peer review is a further reminder that the ‘best ‘ of the science in this area is not even off a standard acceptable for undergraduates essay in any decent university.
That is partly why its so funny to be told that you have to ‘trust’ the science , given the standards in this area are normal so poor , we should anyone actual trust it when its little better than the academic version of ‘what my mate in the pub said’ ?
To paraphrase Prof Jones: ” I have just complered another Nature trick of not adding CO2 proxies to the proxy temp for the last 5000 years to hide the incline.”
To paraphrase Prof Jones: “I have just completed another Nature trick by not adding the CO2 proxies to the proxy temps for the last 5000 years to hide the incline.”
At my comment:
major9985 says:
April 8, 2012 at 3:30 am
The link was meant to be:
http://i44.tinypic.com/34gncox.jpg
My comment at
major9985 says:
April 8, 2012 at 3:30 am
the link was meant to be:
http://i44.tinypic.com/34gncox.jpg
alex says:
April 8, 2012 at 1:34 am
“The correct way is to submit a comment to Nature.
If the editor considers it reasonable (so, you must write it reasonably and there must be a scientist on the author list), it will be passed to peer review.”
Agree, a Comment published by Nature would correct Shakun’s cherry-picking. But since Nature is now motivated by politics over science, I would not expect any such Comment to see the light of day. Like Mann, Shakun is telling them what they want to hear.
That said, it is certainly worth a try, just for the record.
Posted on April 7, 2012 by Willis Eschenbach
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 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.
Each ONE ice core record is unique, Vostok or Bond et al. The truth of describing nature is not to be greater, if individual records are cooked in statistics lump everything together.
If one has the idea that a gas creates heat of saw tooth oscillations ~8° Cel. on Earth over million of years, he may show it by physics. If one has an idea what creates heat of saw tooth like oscillations ~8° Cel. on Earth over million of years, he may show it by physics. A comparison of both is a specious argument and not at all bad science; it is not science.
It is possible to study the unique global records (plural), and you can find phase correlations in the (few) spectra. Each increase of global temperature proxy is powered by a heat source and each saw tooth like frequency has its very own geometry of the heat oscillator.
It is well known here that as well high frequency global temperature oscillations as measured by UAH but also very low frequency global temperature oscillations as recorded in Vostok or by Bond et.al. 2001 have agreements with specific solar tide functions in phase and frequency. The latter can be shown in four graphs because of the big time interval:
http://www.volker-doormann.org/images/vo_m4k.gif
http://www.volker-doormann.org/images/vo_m10k.gif
http://www.volker-doormann.org/images/vo_m15k.gif
http://www.volker-doormann.org/images/vo_m30k.gif
It is one thing to fight against stupidity in the CO2 war, but it leads the scope away from the question what physical processes vary the heat source by which geometries.
An alternative may to verify each anonymous green dot in the graph for correctness. Seems to be a funny job if there are only bad News from xyzgate soaps.
Science is to show agreements in nature, not to being skeptic on possible agreements, because skeptic is not a method of science.
V.
“The enemy is not the CO2, the enemy is you!”
(unknown)
Willis Eschenbach says: April 8, 2012 at 2:46 am
“If they show that, their whole argument is threatened.”
Not at all. Their argument, at least as stated in the abstract, is:
“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.”
They are explaining a specific event, and presented graphs that showed that period.
Nick Stokes says:
“They are explaining a specific event, and presented graphs that showed that period.”
As Willis shows, Shakun et al. were blatantly cherry picking.
Nick Stokes’
The data shows it could go either way. You need to Cherry pick to claim Co2 leads temp.
I had a sneaking suspicion that Willis would come back to this paper. What he has found is similar to hide the decline. Where the authors aware of the rise after their cut-off date?
Willis should send his findings to Nature and see what they have to say about it.
It just goes to show that with enough funding you can make almost any climate related scientific claims you want.
Phillip Bratby says:
April 7, 2012 at 11:41 pm
See “Dishonest, Delusional and Dangerous” – Piers Corbyn dismembers the latest Nature magazine claim propagated by BBC that CO2 drives climate.
http://www.weatheraction.com/docs/WANews12No20.pdf
—————————————
Hi Willis,
could you make a plot with different colours for northern/southern hemispheric data to support/reject Corbyn’s analysis ?
I did a similar analysis of the ice core data with similar results. I observed the proxie temperature deviation beginning around 4000 BC. For a likely explanation of why, see http://www.kidswincom.net/climate.pdf.
Like I said earlier: That Shakun-paper should be withdrawn. This piece clearly shows why.
I hate it when scientists leave the inconvenient parts out. That’s misleading and again it shows “pal-review” at its best.
I definitely never going to subscribe to Nature whatsoever.
To Willis Eschenbach: Are you going to try to convince Nature to withdraw the Shakun-paper?
All this is handwaving unless you write a letter of Comment to Nature and they withdraw the paper
j ferguson says:
April 8, 2012 at 2:01 am
You would have a point if the paper wasn’t trying to turn over such an important theme – that temperature lagged CO2 rise at the end of the last glaciation and therefore CO2 caused the temperature increase. Assuming Shakun et al had the extra CO2 data it shows that CO2 can rise without any temperature increases (a direct contradiction to their central argument) and that CO2 has been rising for 8,000 years, not just since man started burning fossil fuels (a direct contradiction to the heart of AGW).
Nice work Willis. You should publish this. You should also show single graphs of temperature versus year for Greenland and the Antarctic because they clearly show the Antarctic warming up almost 2,000 years before Greenland (there is no way the NH caused the SH to release CO2 to warm the SH).
Someone suggested averaging the time series but if you look at the individual proxies some of them don’t look real and others are neither correlated to Greenland or to Antarctica – so what would you expect from this averaging process?
Anthony,
I think WUWT may be under attack. If I scroll down several screens, I get redirected to a blank WUWT page and can’t get back. This is happening only for WUWT for me, which is why I think it’s directed specifically at you. I’m using IE 9.0.5. (Firefox 10.0.2 is OK for now.)
Good luck.
Bob
Has Willis’ observation that CO2 proxies have generally shown an increase in CO2 beginning 6000BC while temperature proxies have generally shown a decrease in temperature since 8000BC been made before? If so, why isn’t this one of the top 5 arguments to cast doubt on the CAGW hypothesis?
Stokes argument that it was quite right to leave out the later CO2 records because the investigators were focusing on a relatively narrow time period is specious. The writers were using data to hypothesize a mechanism to explain events at a particular time. If that same data extended casts doubt on that hypothesis, a scientist must include that data and explain how the hypothesis is still valid.
Of course Willis explained yesterday why the temperature proxies cannot be averaged – hence the hypothesis is not based on anything scientific to begin with.
Back to my main point – why has the gross relationship of the temp and CO2 proxies over the last 10,000 years not been a prominent argument (that laypeople can understand) casting doubt on the warmers?
Thank you WIllis, excellent postings that resulted in the deconstruction of the paper.
Shakun’s explanation itself was already smelling bad: ice melted first, but that was not global warming, no changes in albedo through ice melting but changes in ocean currents. So North Hemisphere melts ice but it is only South Hemisphere warming which releases CO2 which then creates global warming.
Nick Stokes says:
Willis Eschenbach says: April 8, 2012 at 2:46 am
“If they show that, their whole argument is threatened.”
>> Not at all. Their argument, at least as stated in the abstract, is:
“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.”
>> They are explaining a specific event, and presented graphs that showed that period.
When papers start using phrases like “support the conclusion that …” they are saying they have not proved anything, simply that there is not blatant contradiction with what they are saying. ie yet more unsubstantiated hypothesis. Why these kind of non results are considered worthy of begin published is more to do with politics than science.
Anyone can publish “results” about unproven ideas not being disproved because they and have not tried hard enough and have chosen to ignore half the data that would have disproved them.
If they were then to explain why their “anti-phase” plus in-phase combo becomes “anti-phase” plus “anti-phase” in the last 5000 years we may have something to talk about.
As it is, this is just more IPCC fodder and cargo cult science. Your rather ridiculous attempts to claim it means anything just shows how blinkered you are yourself.
Can picture them now, “And we would have got away with it too, if it wasn’t for that meddling Willis!”.
Great work.
Affizzy, what makes you think they would withdraw the paper?
Nick, you should be questioning your deeply held beliefs.