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.
…
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.
…
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.
…
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:
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“With a clear MWP “
Not so clear to me. As I recall, d18O correlates negatively with temperature.
Oops, I had not realised that the Law Dome Oxygen 18 data set had already been officially ignored by the IPCC as being inconvenient.
‘Ignored’ is probably not exactly correct, as passing reference is made (without illustrations) in the IPCC’s last report, but in a way that no one will realise it is even there. Classic tactics of hoaxers who can then deny any criminal wrong doing, if they are caught out.
Also the Early Middle Ages (c. 5th–10th century) ‘Dark Ages’ don’t look that dark anymore. Today looks a lot ‘darker’.
Nick Stokes siad at 12.39 am
Nick, if you look at the vertical axis, you’ll see that the top reads 20.0 and the bottom reads 23.0.
Does that in any way affect your perception of the MWP, in the light of your revelation that d18O correlates negatively with temperature?
What the heck is the “Law Dome”?
“This data set includes CO2 and CH4 records derived from three ice cores obtained at Law Dome, East Antarctica, from 1987 to 1993. Law Dome is a medium size, approximately circular, (200 km dia., 1390 m high) ice sheet situated at the edge of the main East Antarctic ice sheet. The data in this set include cores drilled between 1987 and 1993 to a depth of 1199.6.”
http://nsidc.org/data/nsidc-0245.html
Location of the Law Dome Ice Sheet?
“measured at approximately annual resolution along the DSS (Dome Summit South) ice core drilled on Law Dome (66.46S, 112.48E, 1390 m above sea level)”
http://climateaudit.org/2012/06/12/an-unpublished-law-dome-series
Which places it here on the map, almost due south of Australia, on the coast of Antarctica.
https://maps.google.ca/maps?q=66.46+S,+112.48+E&hl=en&ll=-47.694974,147.480469&spn=59.194513,63.28125&sll=49.891235,-97.15369&sspn=57.005241,63.28125&t=h&z=4
Why is it named “Law Dome”? Anyone? Was “Law” a person it’s named after? What about “dome”?
Was it only three ice cores that where ever taken? If not how many cores? When? Where is the data?
I have found the Hockey Stick in the above graph:
http://goo.gl/J3wXP
It was quite easy actually – I simply applied a Mannian Tiljander filter to the existing graphic and there it was!
😉
I went to look for what the Taylor Dome O18 series, to see if it were similar. The Taylor Dome shows synchronization between NH and SH climate over the Holocene and seems a more accurate record compared to Vostok at least.
Surprisingly, nothing has been published for the Holocene .
Something that SM has remarked on,
In their figure, they illustrated Taylor Dome from interior Antarctica: here is the bottom panel of Figure 6-2 showing information from Taylor Dome – curiously they show dD values rather than dO18 (shown for the other sites) , even though dO18 is available for Taylor Dome.
I suspect inconvenient truths.
Well posted. Yes, superb thing is it clearly resolves early and late medieval warm periods.
Pointman says:
June 12, 2012 at 11:30 pm
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Too damn right.
I dislike proxy evidence in the sense that you can have no confidence in the correctness or accuracy of the evidence, and any extrapolations drawn therefrom. At best it may give a shape of trends but even that is uncertain.
I do not know how accurate the Law Dome O18 evidence is and whether it is to be preferred to other proxy evidence. However, the mere fact that it is not included and discussed in the IPCC reports clearly demonstrates that these reports make no attempt to impartially examine the science and issues arising from climate and climate change, but instead it is an advocacy document promoting political aims.
This evidence should be promoted to a wider audience with questions being asked as to why it is not included in the IPCC reports.
pat says:
June 12, 2012 at 11:55 pm
Speaking of something not cutting it. Yesterday the wooly mammoth went extinct because of a meteor . Today we discover it was climate change. Not a meteor. Campfire Global Warming. Or something like that.
We found out they tasted like chicken.
From a link in the sidebar: “The bottom line is that we really don’t know why some of these ancient species became extinct,” adds Ted Goebel, researcher in the Department of Anthropology at Texas A&M and affiliated with the Center for the Study of First Americans.
http://www.sciencedaily.com/releases/2011/11/111102161253.htm
Nick Stokes says:
June 13, 2012 at 12:39 am
It is when you learn to read graphs. That would be why the Y axis is ‘upside-down’, or the scale goes from larger to smaller as it goes up.
Looks nice, but again not quite “it”.
The MWP is not long enough. My contention is that the LIA that started around 1300-ish was a catastrophic drop in temperatures from a previously very high point. This has a decline about 150 years early. There also aren’t enough deep troughs in the LIA for my liking.
I have never really been able to define when the MWP started, this looks a bit early to me but I’m willing to be convinced.
“Nick Stokes says: Not so clear to me. As I recall, d18O correlates negatively with temperature.”
Must be hard to go through life with your thumbs in your ears, your fingers covering your eyes and chanting Baaaagh, Baaagh, Baaagh, whenever contrary evidence is presented.
If you know the correlation factor, others would as well and have accounted for it.
As a historian, these charts look much more like recorded history than the hockey stick. I have never heard any AGW chicken little explain the growing of grapes in Northern England in the Middle Ages.
For the confused, the temperature scale on the left is in negative degrees — it’s cold in them thar Antarctic hills. So the warmer temperatures are indeed higher on the axis.
… that is, assuming it is indeed temperature, and not some isotope ratio or some such.
Steve McIntyre reminds me of Einstein or that bloke that painted the ceiling Mickey someone, just sitting there doodling away.
Steve is worth his weight in gold ten times over, I’ll let the readers decide what these so called charlatan scientist are worth their weight in.
Nick Stokes says:
June 13, 2012 at 12:39 am
“With a clear MWP “
Not so clear to me. As I recall, d18O correlates negatively with temperature.
You recall incorrectly.
“In addition, kernel Δ18O correlated negatively with grain yield under well-watered and intermediate water stress conditions, while it correlated positively under severe water stress conditions.”
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2009.02013.x/abstract
Even Gavin Schmidt states as much: “As mentioned above, there are a priori reasons to assume d18O records in terrestrial records have a temperature component. In mid-latitudes, the relationship is positive – higher d18O in precipitation in warmer conditions. This is a function of the increase in fractionation as water vapour is continually removed from the air. Most d18O records – in cave stalagmites, lake sediment or ice cores are usually interpreted this way since most of their signal is from the rain water d18O. However, only one terrestrial d18O record is used by Loehle (#9 Spannagel), and this has been given a unique negative correlation to temperature.”
http://climateaudit.org/2008/11/30/gavin-schmidt-and-uniquely-oriented-speleothems/
Just like the earlier IPCC report which showed a graph of low Arctic sea ice extent in the early 1970s. These climate scientists are seeing what they want to see. Their story is based on biased adjustments and outright fabrications.
Meanwhile over at the Climate Audit site I see this:
[My bold]
Need I say more?
Nick Stokes says:
June 13, 2012 at 12:39 am
“With a clear MWP “
Not so clear to me. As I recall, d18O correlates negatively with temperature
Why is it that sometimes you can appear to be intelligent and at others, like this, well…….you know.
Doug UK says: June 12, 2012 at 11:42 pm
Certainly a “WOW!” moment for me when I read this over breakfast. Ferd Berple is correct – we owe Steve McIntyre a huge vote of thanks.
And Anthony too, just as much, less in some ways but more in other ways. And the team here. Not least the astounding, utterly astounding way Anthony has laboured on and on, under pressure but keeping up the pressure, with almost unfailing courtesy and insight, no time for “feeling off” days.
BTW, there are problems with the ice core record – the oxygen isotope record is fine, no probs there, but there are very serious issues as far as I am concerned, with the CO2 therein encapsulated and the supposed records the ice core shows of CO2 levels.
Please don’t forget folks, it was Al Gore’s (and others’) original use of these two ice core records alongside each other, temperature and CO2, that was a big cause of our current alarmism problems. Certainly it is the scientific weak link that allowed money interests in, and still IMHO needs more air time here on the skeptics blogs. The Ice Hockey Stick. Exactly the same kind of issues as with all the other hockey sticks – improper splicing – but in this case, the fact that it’s spliced is not nearly so obvious.
The ordinate dO(18) scaling doesn’t appear correct. Is it in parts per 10,000? Or a log scale?
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.
Hmm… Anthony, is the vertical axis for the Law Dome graph really temperature in °C? Wouldn’t the peaks before 1000AD correspond with the Dark Ages Cold Period, and the dips after 1000AD be the MWP?
Andrew Harding says:
June 12, 2012 at 11:14 pm
I think in years to come, the hockey stick will rank equally with epicycles as far as science by bigotry goes.
You are doing Ptolemy a great disservice. His theory of epicycles enabled astronomers to make predictions of the movements of the planets that were accurate enough for most purposes and that is why his theory survived for centuries.
What reasonably accurate predictions can the hockey stick gang make?
Nick Stokes says “Not so clear to me. As I recall, d18O correlates negatively with temperature.”
Which is why the y axis in the first graph decreases in value – that is reflecting increasing temperatures….
@Nick Stokes
Does that mean we get to use it upside down?