The 1000 year Australian hockey itch

From the University of Melbourne, I’m sure Julia and Flannery are thrilled at this paleo-reconstruction, and of course, the blame goes on Mann, er man. I find it interesting though that the lead author, Dr Joelle Gergis, thinks of her science work as a “guerrilla war”. From “Science Matters”:

image

Seems like just another angry Michael Mann clone to me.

At the outset of this project in 2010, they said:

Australian climate scientist Professor Chris Turney from the University of Exeter, UK says this meeting will allow us to place Australian records in a global context and gives us an opportunity to fully understand natural climate variability.

Yet in the current press release, the phrase “natural climate variability” is not mentioned. WUWT?

1,000 years of climate data confirms Australia’s warming

In the first study of its kind in Australasia, scientists have used 27 natural climate records to create the first large-scale temperature reconstruction for the region over the last 1000 years.

The study was led by researchers at the University of Melbourne and used a range of natural indicators including tree rings, corals and ice cores to study Australasian temperatures over the past millennium and compared them to climate model simulations.

Lead researcher, Dr Joelle Gergis from the University of Melbourne said the results show that there are no other warm periods in the last 1000 years that match the warming experienced in Australasia since 1950.

“Our study revealed that recent warming in a 1000 year context is highly unusual and cannot be explained by natural factors alone, suggesting a strong influence of human-caused climate change in the Australasian region,” she said.

The study published today in the Journal of Climate will form the Australasian region’s contribution to the 5th IPCC climate change assessment report chapter on past climate.

She said using what is known as ‘palaeoclimate’ or natural records, such as tree rings, corals and ice cores, are fundamental in evaluating regional and global climate variability over centuries before direct temperature records started in 1910.

Dr Gergis collated these natural records provided by decades of work by more than 30 researchers from Australia, New Zealand and around the world.

The reconstruction was developed using 27 natural climate records calculated in 3000 different ways to ensure that the results were robust.

She said reconstructions of regional temperature not only provide a climate picture of the past but also a significant platform to reduce uncertainties associated with future climate variability.

The study is part of a global collaboration, PAGES, Past Global Changes Regional 2K initiative, which is working to reconstruct the last 2000 years of climate across every region in the world in order to reduce uncertainties associated with future climate change projections.

Collaborators include the Climate Change Research Centre and the ARC Centre of Excellence for Climate System Science, University of New South Wales where the climate modeling was conducted.

###

The study was funded by the Australian Research Council, Federal Department of Climate Change and Energy Efficiency and Past Global Changes (PAGES).

Of course, in true Mannian form, the press release has no link to the actual paper. We aren’t supposed to look to closely at this things don’t you know?

And, searching the JoC journal index of the most recent issue shows no mention of this paper, so it must have just been accepted. Does anybody have a copy of this in part or full?

UPDATE: via Marc Hendrickx, thanks.

Paper (PDF)

Briefing powerpoint presentation (PDF)

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Nylo

I believe it was provided to you via a link in tips and notes… Not by me.

Skiphil

“The reconstruction was developed using 27 natural climate records calculated in 3000 different ways to ensure that the results were robust.”
Wow, so many records and calculations, the results must be robust!!
or….. GIGO, garbage in, garbage out???

Tom E

This quarters City Journal has an article ‘APOCALYPTIC DAZE” which is an excellent analysis of why the intellectuals always need to preach doomsday messages such as global warming. They just can not help themselves.

Skiphil, you took the words outta my mouth. How does [exactly] 3000 different ways of calculating 27 variables really make it more robust? Bloviation, that’s how. This is as meaningless a drivel-statement as could be mustered.

It makes it robust to method. One of the complaints that is lodged against Mann, rightly so in some cases, is that his METHOD creates the desired result.
Approaching the problem by using many different ways of combining the 27 variables does in fact give you a more robust result. It is robust WRT the method of combination.
Now, I suppose if we found a correlation to solar activity you would be praising the exhaustive approach they used. But since you dont like the researcher you let that color your judgement,
This is the very same mistake that Mann made when he rejected McIntyre’s criticisms out of hand. He didnt like Steve, so he assumed there must be something wrong with his requests and his math.
Folks would do better to adopt a scientific approach. Get the data. get the code. Look at what they did and make an INFORMED criticism

27 records calculated 3000 different ways. Maybe cherry picked rather than robust could be a more accurate term unless of course all 3000 ways made it into the final data. Then it would just be GIGO.

MarkW

In a world that’s some 4 billion years old, they declare that if something hasn’t happened in the last 1000 years then it can’t possibly be natural.
Right.

See Cook et al., 2000

With the collection and dating of additional sub-fossil Huon pine wood from Mt. Read, Cook et al. (1996a) extended the Tasmanian temperature reconstruction back to 800 BC. New spectral analyses of this 2792-year reconstruction again verified the probable existence of the previously identified inter-decadal and century-scale oscillatory modes, now with mean periods of 31, 56, 78, and 200 years. Using singular spectrum analysis (Vautard et al. 1992), Cook et al. (1996a) showed that these oscillatory modes were present throughout the record, but were strongly amplitude modulated. Collectively, they explained about 12% of the variance in the unfiltered temperature reconstruction and about 41% of variance in the 10-year low-pass filtered reconstruction. Interestingly, these modes could also account for approximately 51% of the warming over Tasmania since 1965, with the remaining 49% due to other processes. Finally, Cook et al. (1996a) showed how these natural oscillatory modes could theoretically mask future warming trends over Tasmania due to greenhouse gas forcing.

“New spectral analyses of this 2792-year reconstruction again verified the probable existence of the previously identified inter-decadal and century-scale oscillatory modes, now with mean periods of 31, 56, 78, and 200 years.”
Reconstructions are built from real data (AKA observations). The *real data* “again verified the probable existence of the previously identified inter-decadal and century-scale oscillatory modes, now with mean periods of 31, 56, 78, and 200 years.”
A 200-yr “century-scale” oscillation would look a lot like a “long-term trend” to people unfamiliar with spectral analyses. Like this:
Tasmania 1800-2011
I used a tree ring reconstruction from Mt. Read and the instrumental record from Hobart Airport…
Tasmania Map
To build a quick warm season climate reconstruction for Tasmania over the last ~3,600 years…
Tasmania 3600-yr
The last 60 years may very well have been the warmest 60-yr period over the last millennium. It might be 0.1°C than the 60-yr peak in the early 1400’s. So what?
Prior to the Little Ice Age, these sorts of peaks were hit roughly once every 200 years. The peaks were anywhere from 15.2-15.5°C. The average temperature at Hobart Airport over its 54-yr record is 15.5°C.
The Little Ice Age was possibly the coldest part of the Holocene since the 8.2 KYA Cooling Event. The LIA was cold because the millennial-scale cycle was in its cold phase, there were several deep solar minima and there was an anomalous period of volcanic activity ca 1200-1400 AD, most notably the ca 1300 AD eruption of El Chichón. The peaks of the ~200-yr cycle were suppressed by from ~1400 AD through the end of the LIA.
From the Guardian article

Dr. Steven Phipps, from the Climate Change Research Centre at the University of New South Wales, who carried out the modeling, said the study demonstrated strong human influence on the climate in the region.
“The models showed that prior to 1850 there were not any long-term trends and temperature variations were likely to be caused by natural climate variability which is a random process,” he said.
“But [the modeling showed] 20th-century warming significantly exceeds the amplitude of natural climate variability and demonstrates that the recent warming experience in Australia is unprecedented within the context of the last millennium.”

Modeling will show whatever the modeler wants it to show.
The paper is pretty interesting. Here’s their proxy reconstruction ensemble:
Gergis Ensemble
One of the things that immediately caught my eye was the fact that the onset of the anomalous warming in their multi-proxy reconstruction coincided with the anomalously cold period in the early 1900’sand that when I plot their reconstruction on my much longer reconstruction, the last 60 years do not appear anomalous at all.
Gergis in Late Holocene Context
Gergis et al. have once again rediscovered the warm-up from the Little Ice Age.

John W.

I heard an interview with Dr Joelle Gergis during my morning commute (ABC on the WRN over SiriusXM). If I recall correctly, she said they saw some evidence of natural variation, but nothing as severe as in the recent record. The “3000” bit jumped out at me. She seemed to be saying they kept torturing the data until it confessed. Typically, the suck-up doing the interview didn’t ask anything but softball questions.

Billy Liar

Adrian Smits says:
May 17, 2012 at 11:24 am
cherry picked rather than robust could be a more accurate term
Exactly! You get what you pay for.

Steven Mosher says:
May 17, 2012 at 11:21 am
http://www.pages-igbp.org/workinggroups/aus2k/metadatabase
=============================================
Not a very wide latitude???.

HR

Antony,
I found contact details for her (?) at unimelb
http://www.findanexpert.unimelb.edu.au/researcher/person203094.html
I found a website for her research.
http://climatehistory.com.au
The publications page lists the paper you are talking about here but it doesn’t have a clickable link. Still marked as “in press”
http://climatehistory.com.au/publications/

Keith W.

Michael R posted a link to the pre-paper that is behind a paywall, as well as a link to a copy that he purchased at http://wattsupwiththat.com/tips-and-notes/#comment-987292

“natural records, such as tree rings, corals and ice cores”?
What, no tea leaves, chicken entrails, or smoked fungi?
What I see here is not mensuration science. It is that someone has collected bits of string and called the collection a ‘rope.’

tonyb

lets give some context to this paper which is from a scientist who is employed in a climate change capacity so has something of a vested interest. He was involved in an interesting programme on climate change on British Tv recently and was pretty good
http://www.exeter.ac.uk/research/excellence/keythemes/climate/news/title_50043_en.html
tonyb

Glenn
George Lawson

“Our study revealed that recent warming in a 1000 year context is highly unusual and cannot be explained by natural factors alone,”
Why not?

Mike McMillan

“. . . that the lead author, Dr Joelle Gergis, thinks of his science work as . . .”
“her,” not “his”

Gary

“Folks would do better to adopt a scientific approach. Get the data. get the code. Look at what they did and make an INFORMED criticism.” Seconded. Anything else is driven more by ideology than a search for understanding of nature.

Hi Glenn,
From the link you posted:
“The unusual 20th century warming cannot be explained by natural variability alone…”
Why not? They don’t say why not. Natural variability has changed global temperatures by more than ten degrees over very short, abrupt times during the past 12,000 years. So their statement is the usual Argumentum ad Ignorantium: ‘Since we can’t think of any other reason for the 0.09º rise, then it must be due to anthropogenic forcing.’ <– [the argument from ignorance.]
And note that the cherry-picked ['last 1,000 years'] time frame is also limited to Australasia. It is not global, only a regional variation. Despite all those problems, they probably still got their grant.

DBCooper

Yawn.

Latitude

the results show that there are no other warm periods in the last 1000 years that match the warming experienced in Australasia since 1950.
==================
Well of course not…..
The first 500 years temps were falling into the LIA…
The second 500 years, temps were much lower and none of that rising record would “match” because you start low and go high………..

tonyb

Thanks to Mosh for linking to the paper. Its a neat format, although I found it hard to see the location and type of proxies used without constant zooming. Must be some easier way to view all the data so I will have a fiddle.
As far as I can see The Australasia part of the study has 27 records. Around nine are in Australia and the remainder in New Zealand. As far as I can tell the NZ ones are mostly tree rings whilst the Australian ones include sediments. Its a very large area for so few records covering such a long period and this imprecise factor is multiplied many times as so many of the records are tree rings. Tree rings can not give us the means to calculate precise temperatures.
I have been looking at the 13th and 14th Century records in the archives of Exeter Cathedral today and came across a tree ring study made by English Heritage (a Govt Body) of the timbers of this thousand year old building. The study was from around 1999. It said that tree rings were good for approximate dating (which I accept and was the prime purpose of the study) and that it could tell us years that were worse or better than average climatically (moisture etc during the growing season) but cautioned against trying to determine any more precise details than that.
Somewhere between today and 12 years ago the study of tree rings became highly elevated in importance and scope and diverged from its original purpose of dating. I can only think it was Dr Mann who gave it the undeserved celebrity it enjoys today.Tree rings are not a precise science however much they are promoted as being so.
tonyb

Dave Wendt

steven mosher says:
May 17, 2012 at 11:57 am
“Folks would do better to adopt a scientific approach. Get the data. get the code. Look at what they did and make an INFORMED criticism”
That is a fairly reasonable suggestion, except that we are now in the age of PR “science” where the growth in the length of time between the release of the hyperbolic announcement of a study and the actual availability of the work is accelerating about a thousand times faster than the worst case claims about sliding ice sheets. The compliant media who will be ballyhooing this PR aren’t really interested in including any cautionary comments right now. By the time the paper actually appears their interest will have disappeared entirely. When it finally appears this study might turn out to be sterling work but, based on 2-3 years of experience with the ongoing flood of this type of nonsense, I suspect there is a rather direct relationship between the length of time between the PR and the actual availability and the overall quality of the product. That’s just an eyeball assessment and hypothesis, but perhaps a stat guy like yourself could do an analysis to contradict my perception.

Dave Wendt

Dave Wendt says:
Your comment is awaiting moderation.
May 17, 2012 at 1:02 pm
steven mosher says:
May 17, 2012 at 11:57 am
BTW, as an addendum to the above I would note that the metadatabase you linked included 196 works. Any clues yet on which 27 actually made the cut or what the selection methodology was that eliminated the other 86%?

First things first. Everyone understand this: there is nothing wrong with the climate.
It was the bullshit and fully debunked hockey stick that implied that there was something wrong. There is nothing wrong.

EternalOptimist

Mosher is right….BUT
People see a great wrong, they are not scientists. They are not as capable as Mosher, with regards to the data or the code,
they dont like the tone or the approach or the tenor of the alarmists
or they have an objection to alarmism
so What do they do Steve ? keep quiet ? cheer from the sidelines ? make funnies ?
what would you have them do ?

Tez

It seems to me that this report confirms the existence of the medieval warm period affecting australia 1000 years ago. Why dont they report that to the IPCC?

Myrrh

The “Last thousand years” is a hockey stick meme in research, whatever happened in Australia in that time will be connected to the same patterns of El Nins as South America, as far as I’m getting to grips with the subject, and there’s lots of research already done which should have this, such as: http://researchnews.osu.edu/archive/quelcoro.htm
“Coropuna is located on the first rise of the Andes, right above the Pacific Ocean, so the ice cores should record changes in the El Nino-La Nina cycle, a key component of climate variability.”

Streetcred

steven mosher says:May 17, 2012 at 11:57 am
—————————-
Gergis is just another socialist environmental shill on the teat of the public purse.
http://www.australianclimatemadness.com/

Ally E.

All I can tell you is that its getting colder here in NSW. We’re not officially into winter yet but we’ve been getting frosts on and off over the last two months. This morning, as I type, it’s -5.5 C. (around 20 F, I believe) and the countryside is white with frost. I don’t know how long they can keep insisting it’s getting warmer when it clearly and obviously is not.

Curious George

” … calculated in 3000 different ways to ensure that the results were robust.” As Dr. Goebbels used to say, a lie repeated 1000 times becomes a truth. Now we get a triple-truth.

Latitude

seems to be a wiggling of words too…..
“The findings show that no other period in the last 1,000 years matches the temperature rises Australia and the region has experienced in the last 50 years.”
“the results show that there are no other warm periods in the last 1000 years that match the warming experienced in Australasia since 1950.”
No periods would match the “rises”…only half of that 1000 years would temps be rising…and each “period” would start with a lower temp and end with a lower temp….
No warm periods would match the “warming”……for the same reason….starting at a lower temp and warming to a lower temp
The first 500 years were falling into the LIA….the last 500 were rising from the LIA
I don’t see any reason to debate the “science” at all….

Follow the Money

“The study was led by researchers at the University of Melbourne and used a range of natural indicators including tree rings, ”
Tree rings? Really? Australia has boreal forests? The theory tree rings MIGHT be more temps than water budget meters only was surmised to apply to tree-line flora. That’s why bristlecones and trees at Yamal in Siberia are looked at. Is this Australian study a new avenue in climate science??

Thevauthors are interviewed at this link http://www.abc.net.au/radionational/programs/breakfast/climate-research-shows-human-caused-warming/4016322
A statement made in the interview is “We used climate modeling to actually look at what the drivers of climate are, and by using the modeling, we were able to show that lateral factors alone cannot explain the warming that we saw during the 21st century.” correct me if I am wrong, but doesn’t this mean that they use models which ignore some natural factors to prove that the model they are using is correct?

Werner Brozek

On the other hand, the following seems to indicate that New Zealand was about 0.7 C warmer during the MWP as in 1950.
http://wattsupwiththat.com/2009/11/29/the-medieval-warm-period-a-global-phenonmena-unprecedented-warming-or-unprecedented-data-manipulation/

mfo

“Lead researcher, Dr Joelle Gergis from the University of Melbourne said the results show that there are no other warm periods in the last 1000 years that match the warming experienced in Australasia since 1950. ”
————–
At JoNova:
“A team of independent engineers, scientists, statisticians and data analysts (brought together by the joannenova blog) has been going through the Australia Bureau of Meteorology records (BOM). They’ve audited some 8.5 million daily observations across 237 High Quality and other close sites in Australia.
“This audit of a large sample of daily temperature observations at all sites associated with Australia’s High Quality Temperature Network provides convincing evidence that the record is of very poor quality and is replete with errors.
“The large amount of uncertainty in the records of so many sites means that homogenisation as practised by BOM researchers must be in question, and with it all analyses of Australia’s temperature trends plus the calibration of past proxy studies. ”
Best to read the whole post here:
http://joannenova.com.au/2012/03/australian-temperature-records-shoddy-inaccurate-unreliable-surprise/

Dave Wendt

Looking thru the metadatabase that Mosher linked, the breakdown appears to be approx. 50%+ tree ring proxies, 40%+ coral proxies, and 5%+ marine sediments. The Idsos have also assembled a database of proxy studies which includes the study area involved here.
http://www.co2science.org/data/mwp/mwpp.php
The differences in format and nomenclature make it difficult to determine which studies may be included in both but the proxy types included suggests the overlap will not be large. Since the Idsos database is admittedly focused on studies which indicate a warmer MWP, if those studies have indeed been excluded, systematically or otherwise, it would raise questions, in my mind at least, of just how dedicated these authors were to developing a true record.

Mac

There could be a major problem with this study. Most of the data are from New Zealand tree-ring studies and we must remember the problems that NIWA got themselves into with its “Seven-station Series”.
It would be interesting to see a comparison between New Zealand’s tree ring record from this study and the recent re-analysis of New Zealand’s Temperature Record

Jimbo

They should have tried the last 12,000 years. Minoan & Roman inconvenience.
It must be co2! Why? We can’t think of anything else. Where is the evidence?

John Gardner
Dave Wendt

Whoops! I forgot to include the ice core studies in my breakdown, which would reduce the coral studies from 40% to approx 30% with the ice cores accounting for approx 10%.

Aynsley Kellow

It is worth noting that the commencement of the temperature record in Australia in 1910 is when the (then recently established) Australian Bureau of Meteorology commenced its records. It is not the case that there are now prior records — just that they are dismissed as unreliable. The official records therefore miss the ‘Federation Drought’ that followed the formation of the Australian Federation in 1901.
I think there is always need for caution when the basis of data changes, especially if we do not have continuity, but it would be interesting to see what the actually temperature records before 1910 say. Species like Huon Pine are particularly slow growing, and I’m not sure how sensitive they are to temperature (as opposed, eg, to moisture). It would seem strange to prefer them as temperature proxies when actual observations are available, regardless of problems in the observational data.
David Middleton: Interesting analysis, but why Hobart Airport? Wouldn’t Hobart have a longer record? Are there not stations close to Mt Read (eg Strahan)? How long do they stretch back?

John Trigge (in Oz)

Whilst (there it is again, Anthony) this ‘research’ may have some value I have 2 questions:
1. shouldn’t we wait for the peer review process to grind through its laborious processes before accepting this as a forward step in knowledge? I offer:
“None of the experts who have scrutinized the specimens and the gravel pit and its surroundings has doubted the genuineness of the discovery.”
— William Gregory, in Natural History reporting on the Piltdown Man fossils

2. so what if our temps are on the rise? Flim Flammery’s (an Australian Climate Change Commissioner with 180,000 climastrophic reasons per year) prognostications have all failed and, as the 60 years of warming since 1950 haven’t swept Oz into the sea, why will the next 50 or a 100 do so?

X Anomaly

The climate (funding) is very, very sensitive…..
I’m getting tired of this virtual gaia crap

Chuck L

Ally E. says:
May 17, 2012 at 1:36 pm
All I can tell you is that its getting colder here in NSW. We’re not officially into winter yet but we’ve been getting frosts on and off over the last two months. This morning, as I type, it’s -5.5 C. (around 20 F, I believe) and the countryside is white with frost. I don’t know how long they can keep insisting it’s getting warmer when it clearly and obviously is not.
Ally, don’t you know that cold temperatures are only “weather” and warm temperatures are manmade climate change? /s

kasphar

I wonder if they included this study from NZ.
http://pages.science-skeptical.de/MWP/Wilson-1979.html

Steve McIntyre

She was coauthor with Neukom in an article last year on SH proxies, cited in AR5. Much of the data is not archived. I asked Neukom and he told me to suck eggs.
http://climateaudit.org/2012/01/19/neukom-and-the-steig-overunder/
http://climateaudit.org/2011/01/06/more-data-refusal-nothing-changes/
http://pages-igbp.org/download/docs/Neukom_Gergis_2011.pdf

AndyG55 (from down-under)

hmm.. the last 50 years..
all the previous period was constructed from proxies, but how was the last 50 years constructed..
From land temp measurements (often affected by urbanisation., have they accounted properly for that.. I doubt it very much.. the AGW bretheren never do)
do they maintain tree proxies.. if they have, do they correct for the rise in the CO2 level, which make tree much more efficient..
Oh , and, What errors range are they claiming for their temperature reconstruction ?

Roger

I did my PhD in an Australian University would not trust an Australian Scientist as far as I could throw him/her especiailly an environmentalist