Read on for a new Josh cartoon.
What’s wrong with this image? Well if you are part of The Team (RealClimate and friends), it goes against everything you’ve been publishing. You want the Medieval Warm Period to disappear, and you want a hockey stick at the end showing “unprcedented” warming. The shape below just doesn’t cut it when that’s what you are researching selling.
On the left is temperature in °C, on the X axis, years, with labels from 0AD to the year 2000.
Images like the above don’t sell. With a clear MWP and no hockey stick, there’s no alarm, and no $$ coming in for “further studies”. In the Wake of the Gergis et al retraction, Steve McIntyre notes that one of the “screened out” datasets just happens to be the one with the best resolution and the greatest duration – the Law Dome Oxygen 18 data set (from Antarctica). He writes:
An annual version for two millennia was provided to Gergis (who screened it out.) delD and O18 are closely related and presumably the unarchived del D series will look somewhat similar.
For those that don’t know what this data represents, here’s a quick primer from Wikipedia.
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Oxygen isotope ratio cycles are cyclical variations in the ratio of the abundance of oxygen with an atomic mass of 18 to the abundance of oxygen with an atomic mass of 16 present in some substances, such as polar ice or calcite in ocean core samples. The ratio is linked to water temperature of ancient oceans, which in turn reflects ancient climates. Cycles in the ratio mirror climate changes in geologic history.
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Connection between temperature and climate
The 18O/16O ratio provides a record of ancient water temperature. Water 10 to 15 °C (18 to 27 °F) cooler than present represents glaciation. As colder temperatures spread toward the equator, water vapor rich in 18O preferentially rains out at lower latitudes. The remaining water vapor that condenses over higher latitudes is subsequently rich in 16O.[2] Precipitation and therefore glacial ice contain water with a low 18O content. Since large amounts of 16O water are being stored as glacial ice, the 18O content of oceanic water is high. Water up to 5 °C (9 °F) warmer than today represents an interglacial, when the 18O content of oceanic water is lower. A plot of ancient water temperature over time indicates that climate has varied cyclically, with large cycles and harmonics, or smaller cycles, superimposed on the large ones. This technique has been especially valuable for identifying glacial maxima and minima in the Pleistocene.
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McIntyre adds:
Oxygen isotope series are the backbone of deep-time paleoclimate. The canonical 800,000 year comparison of CO2 and temperature uses O18 values from Vostok, Antarctica to estimate temperature. In deep time, O18 values are a real success story: they clearly show changes from the LGM to the Holocene that cohere with glacial moraines.
On its face, Law Dome, which was screened out by Gergis and Karoly, is an extraordinarily important Holocene site as it is, to my knowledge, the highest-accumulation Holocene site yet known, with accumulation almost 10 times greater than the canonical Vostok site. (Accumulation is directly related to resolution: high accumulation enables high resolution.) The graphic below compares glacier thickness for some prominent sites for three periods: 1500-2000, 1000-1500 and 0-1000. its resolution in the past two millennia is nearly double the resolution of the Greenland GRIP and NGRIP sites that have been the topic of intensive study and publication.
Given the high reliance on O18 series in deep time, one would think that paleoclimatologists would be extremely interested in a publication of the Law Dome O18 data and be pressuring Tas van Ommen on this point.
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But despite the apparent opportunity offered by Law Dome, there has been virtually no technical publication of a high-resolution O18 or delD isotope series.
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A Climategate email shows that Phil Jones asked about the omission of the Law Dome series from the IPCC illustration in the AR4 First Draft. I asked the same question about the AR4 Second Draft. They realized that the Law Dome graphic had an elevated medieval period and thus, including it in the graphic would – to borrow a phrase from the preparation of AR3 – would “dilute the message” and perhaps provide “fodder to skeptics”.
Read the whole report at Climate Audit here
The Team keeps trying to bury this stuff, and Climate Audit keeps digging it up:
Ah, a minor point. Delta O-18 is a negative fraction, so the Y-axis is not upside down. The ratio between the sample and standard concentrations are subtracted from 1, so larger amounts of O-18 in a sample correlate positively with higher temperatures. If you all glance at that graph again, there are negative signs preceding delta O-18 numbers.
“Phil Clarke says:
June 13, 2012 at 11:01 am
LZ:- I can’t see much temperature variation corresponding to modern thermometer readings.
Indeed. Also I notice that the MWP down South was between about 700 and 1000 AD. About 3 centuries before it is purported tohave occurred in Europe.
Not global, then.”
But it does show a tiny, tiny, bit of late 20th century warming. Looks about right to me….
The recent Gergis and Karoly paper not only screened out the Law Dome paper. They also
1) Included two from Vostok ice core proxies covering just 226 years. The same paper, but different methods. One had a C20th warming rate over 5 times the other.
2) Included the Palmyra Atoll coral proxy. This had the fastest C20th warming rate of any proxy – a significantly cooler C12th than the two 1000 year tree-ring proxies.
I have some relevant graphs and data at
http://manicbeancounter.com/2012/06/11/how-gergis-suppressed-the-medieval-warm-period/
Phil Clarke says:June 13, 2012 at 11:01 am
“……..I notice that the MWP down South was between about 700 and 1000 AD. About 3 centuries before it is purported tohave occurred in Europe….. Not global, then.”
Indeed, and the whole point of Gergis et al was to show ‘current warming’ IS global …. and that appears to require some ‘data convolutions’…..maybe the hemispheres are not quite so ‘in sync’?
Tas van Ommen, who’s done the work …..
http://www.sciencepoles.org/articles/article_detail/tas_van_ommen_the_information_ice_cores_from_law_dome_provide/
I read the interview…even though his own data shows profound cooling, he says it confirms climate change theory…
When discussing δ18O, Wikipedia says
and McIntyre agrees. While this may be true for ice cores, the ratio in ocean calcite cores is linked to salinity and has nothing to do with temperature.
I have not found any good reference that publishes both δ18O and deuterium for the same core. However, I have combined 2 separate Vostok data sets – δ18O and deuterium – and discovered that there is NO correlation. It should be obvious to everyone that there is a problem. Specifically, deuterium indicates that there are 4 interglacials recorded in the Vostok ice core – δ18O indicates 8 (eight) or more.
http://mc-computing.com/qs/Global_Warming/Icecore_Data/images/Vostok_200x320_Deu_18O.jpeg
[SNIP: John, your enthusiasm and commitment are admirable, but this has nothing to do with the topic of this thread and WUWT is not a soapbox for anyone to preach from. Sorry. -REP]
Interesting. Could the Law Dome findings lead to some individuals being brought to law?
From what I remember the the O16 to O18 ratios are determined at the point of evaporation and carries no additional information from transit or deposition. What I also remember is that it takes more energy to evaporate water containing O18 just as it takes more energy to evaporate water containing deuterium (heavy hydrogen).
Katherine says:
June 13, 2012 at 1:51 am
A bit of a fail on Josh’s cartoon. The Climate Audit bulldozer looks set to cover up the reports being dumped. It ought to be an excavator if he wants the meaning to be clearer….
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I agree he needs to put in a backhoe instead of the bulldozer: backhoe photo
Nice find by Steve M. goes well with the Greenland graph: http://4.bp.blogspot.com/_cHhMa7ARDDg/SsZbFvC5SJI/AAAAAAAABLY/uZxh6g17bmE/s1600-h/GISP2_10Ke.jpg (note hockey stick spliced onto the end highlited in yellow)
COB says:
June 13, 2012 at 3:18 am
By the way where is Lazy Teenager?
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On his way to Rio – 20 of course! (/sarc)
Again this is a great blog. I just re-read the article and the references. It looks like there is also O16 O18 partitioning during precipitation. I have just updated my old knowledge data base.
Thank you again.
Latimer Alder says:
June 13, 2012 at 9:14 am
Can you please tell me when the ‘warm’ bit of global warming will kick in for UK? I see all these lovely hockey sticks promising us an improved climate…but it never seems to come.
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Here on the west coast of Canada we are celebrating a brand new month – Junuary. Cold and wet like January, but it happens in June. Warmest decade my ass.
While on the subject of O16 to O 18 ratios I just ran across a paper that shows that there is fractionation taking place due to sublimation, after deposition as snow. (http://iahs.info/redbooks/a114/iahs_114_0122.pdf)
Does this mean that thick deposits of are more representative of the source and transit temperatures? I noticed that Law Dome had thicker layers mentioned.
Are the thinner deposits that are subject to sublimation modified and have a local signal added to them?
@ur momisugly Barry R: June 13, 6:55 am
The second, longer scale graphic is mislabeled. The time units at the bottom should be in thousands of years, not millions.
No, Barry. The second graph with Cm, O, S, D, C, P….. is a Geologic Time Scale with Cambrian (about 550 million years ago) to present.
Tr, J, K, are the Triassic, Jurassic, Cretaceous which ends at about 65 million years ago.
The uncertainty in the actual number of years is down to about 1%
One of my favorite charts is Manfried Menning, “A Synopsis of Numerical Time Scales: 1916-1986”
See: http://www.episodes.co.in/www/backissues/121/ARTICLES–3.pdf
There is a loose chart about 2 x 3 feet, that compares the time (millions of years ago) for each geologic age and epoch, by about 20 different major authors. It is a beautiful example of uncertainty in science and how a science wrings out the uncertainty over time.
@Nick Stokes
> I see at CA that in fact the Law Dome d18O data
> is available, and has been for some years.
I clicked on the link which lead to this site (via climateaudit):
sites.google.com/site/silenvuea/research-highlights/gomez-nunatak
The data at this link is from Gomez Nunatak ((73°57′S 68°38′W), not Law Dome (66°44′S 112°50′E), which is located on the opposite side of the continent:
But just for grins I looked at the data and plotted it here:
http://www.qsl.net/a/af4ex//images/gomez-plot.png
Note that the x-axis is calibrated in meters, so the low xvalues correspond to the top of ice i.e. recent times. The writeup with the data states that it conists of 2314 data points covering 150 year (1855-2007), which makes sense, consistent with late 20th century warming trend.
This can’t be the plot in the article because Anthony claims that it covers 2000 years.
But I’m a bit skeptical about the x-axis labeling. Nobody would use Common Era dates on a numeric scientific plot, because there is a discontinuity at 0 CE. Typically one would use an offset in years from present time etc.
Now the Gomez plot had about 2218 points (with 110 missing values which I filled in with mean values from the time series). So is it possible that Anthony’s x-axis is just a count of data points, not years? In other words this might just be raw data, not calibrated to temperature (which might explain the unusually low recent temps)
Can someone point me to documentation on this particular Law Dome ice core, which will verify that it is calibrated accurately for temperature over a 2000 year span? Other factors (e.g. volcanism) can also create spikes in these 018/O16 plots. So some sort of calibration routine (yikes, a model!) must be applied to smooth and correct for these aberrations and other noise.
😐
:
John Day says:
June 13, 2012 at 8:12 pm
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The Gomez ice core has nothing to do with the Law Dome ice core. Nick Stokes was mistaken when he brought attention to the post on Climate Audit by Paul Dennis of UEA (who was a co-author on the Gomez ice core paper). The metres of accumulation in Gomez have been translated into “time” which only goes back to 1857.
The issue is – why has this high resolution do18 temperature proxy ice core from Law Dome been suppressed.
There isn’t a lot of opportunity to provide annual (or even decadal resolved) temperature estimates from the ice cores. Law Dome is one of those that has very high accumulation rates and therefore we can get annually resolved CO2 / Methane / Lead measurements from Law Dome (which are published) but the do18 temperature proxy data has been withheld by the scientists who gathered it (other than an email to Steve McIntyre and to many of the ClimateGate scientists).
It obviously didn’t fit with the global warming storyline. Michael Mann would obviously not use it for a hockey stick reconstruction and neither did the IPCC or anyone – because it has been suppressed.
Unprecedented late 20th century global warming is our very own un-dead Piltdown Man. Maybe its Son of Piltdown Man.
“””””…..cui bono says:
June 13, 2012 at 5:30 am
Roy says (June 13, 2012 at 1:59 am):
You are doing Ptolemy a great disservice.
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Absolutely. And it cost the taxpayers nothing for 1500 years despite being wrong……”””””
Where did you get the idea that Ptolemy’s epicycle theory is wrong. Of course it is correct. Why don’t YOU take whatever 21st century theory you happen to believe, and then transfer the origin of your co-ordinate reference frame, from the sun to the earth; and then explain how it is different from Ptolemy’s epicycles.
I do believe it was Albert Einstein who told us there is no absolute reference frame.
I actually found a book in my old alma mater library, that had a full description of Ptolemy’s epicycles, with simply stunning graphs. As I recall, it also had a derivation of the elastic properties of the “ether” medium, in order for it to be able to propagate waves at the velocity of light.
Either one is a whole lot easier to understand as well as believe, than string theory is.
Old and busted: Hockey Stick.
New Hotness: Molehill?
I’ve updated my page on the Ice Hockey Stick concerning the ice core record of CO2 which I regard as the biggest scam going, still not widely commented-on, and with Al Gore’s input, the mother of all our AGW alarms. Will do an article if I can, after Graeff.
In checking out the availability of ice core date in relationship to the Gergis debacle, I found this NOAA graph which shows CO2 at around 200ppm for a long time… but plants starve at that level of CO2.
Yeah, you get to offer the first guess what happens to data when it gets “proceesed”. Don’t bother being polite!
😉
Has the paper been killed or is it coming back?
@Bill Illis
> The Gomez ice core has nothing to do with the Law Dome ice core.
> Nick Stokes was mistaken …
Yes, of course
1) The two sites are on opposite edges of the Antarctic continent
2) The Gomez core data sample covers only 150 years from present
But Tas van Ommen, who seems to have been the principal investigator for the team which studied this 2000 year Law Dome sample, claims the findings have been published and the data for this sample are ‘publicly available’:
http://climateaudit.org/2012/06/12/an-unpublished-law-dome-series/#comment-337947
Question is: where are these ‘publicly available’ findings and data? Is Tas telling the truth?
Sorry if someone has already answered this question above. I skimmed so might have missed it.
😐
No, Barry. The second graph with Cm, O, S, D, C, P….. is a Geologic Time Scale with Cambrian (about 550 million years ago) to present.
Tr, J, K, are the Triassic, Jurassic, Cretaceous which ends at about 65 million years ago.
The uncertainty in the actual number of years is down to about 1%
Oops. Misread that. A graph going back several hundreds of thousands of years would actually make more sense there, in my opinion, but you are right.
John Day says: June 14, 2012 at 5:57 am
Yes, I too wondered where Tas van Ommen’s “publicly avilable” data are, apart from Steve’s laptop. I looked at the ITASE IceReader which Wikipedia mentions, which appears to be the de facto website for ice core data, and does have a lot of NOAA and NSIDC links (about a quarter of the 200 ice cores mentioned) but doe NOT have URL links for Law Dome.
Can anybody help?