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”:
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.
Briefing powerpoint presentation (PDF)
The last paragraph of the abstract
In 94.5% of the 3000-member reconstruction ensemble, there are no other warm periods in the
past 1,000 years that match or exceed post-1950 warming observed in Australasia. The unusual
20th century warming cannot be explained by natural variability alone, suggesting a strong
influence of anthropogenic forcing in the Australasian region.
These people need to go back and redo some undergraduate science classes, particularly those that deal with the null hypothesis and statistical significance.
I can’t believe such an obvious error made it through peer review, but then this is climate science.
Anthony
Here is a 15 year projection for a “permanent El Nino”
‘That’s a theory endorsed by Dr Russ Schnell, a scientist doing atmospheric research at Mauna Loa Observatory, 11,000 feet up on Hawaii. “It appears that we have a very good case for suggesting that the El Ninos are going to become more frequent, and they’re going to become more intense and in a few years, or a decade or so, we’ll go into a permanent El Nino.“‘
http://bbc.in/daNhmH
“Only records that were significantly (p<0.05) correlated with the
226 detrended instrumental target over the 1921–1990 period were selected for analysis."
Oh Oh. Cherry picking?
"Instrumental HADCRUT3v combined land and ocean temperature data over the 1900–2009 period shown in green"
Global or SH?
Can’t access the paper without paying for it so difficult to critique, however in their report they define the medieval warm period as a 30 year period in the 1200s. 2 things :
1) In just about every article I can see the Medieval warms period is some 300 years long starting about 950 and ending about 1250 and the earlier bit seems warmer;
2) Most articles indicate that there is some dispute as to whether the Medieval warm period was a global phenomenon.
What is interesting about this is that the article is reported as saying that they can account for all variability by natural processes up to 1950, but if they really believe that the Medieval warm period was just 30 years then they are looking at a very difficult historical record than the rest of us.
I personally like the fact that there are, of course, no human records that can be referred to. Around the Atlantic you have inconvenient things like Vikings living in Greenland and Monks getting drunk on wine in Kent because England was the best wine growing area in Europe. In Australia, there is no such history to embarrass folks when they are developing an “historical” record.
Thanks to UnfrozenCavemanMD for the link.
From the accepted, peer-reviewed preliminary online version (my bold):
GASP!
That’s erm… Eastern South Pacific, South America, South Atlantic, equatorial and southern Africa, parts of the Indian Ocean including the tip of India, the island of Ceylon and none of the Australian continent. Not even close to “Australasia”.
Not one of the reviewers questioned that? Earth scientists without a globe must be some peer group. Makes me wonder how many of those reviewers actually read and think about what they are reviewing.
If you look at Figure 1, this is tree rings from 1000 to around 1993 when a big drop off occurs. Shades of hide the decline? All the tree rings are in New Zealand or Tasmania. Corals are big from around 1900 … and the Vostok ice core makes an appearance at 1774. No ice core data before that?
http://i46.tinypic.com/rapvn7.jpg
Cherry picking proxies.
Question regarding the PAGES data. I’ve navigated through to the Ningaloo Reef data set (well, the readme) to find:
The BoM data from nearby Onslow Airport which has temperature data from 1943 to 1973 shows a slight dip in max/min means for 1963 for the months but I’ve not had a chance to do any more than to plot the points and to fit some curves. Way short of proper stat’s to say if Agung produced an anomaly that should have affected coral growth.
nano pope says:
May 17, 2012 at 3:49 pm
Well who would have guessed that there is thousand year old ice in Australia.
There are some very old pubs in Sydney and they don’t clean the walk-ins that often…
goldie says:
May 17, 2012 at 7:02 pm
“. . . England was the best wine growing area in Europe.”
Can you give a reference, please, to the date and circumstances of the competition that determined the above? Were all the judges drunk monks from Kent or were there a few winegrowers from Burgundy and Tuscany?
Here we go again, another attempt to rewrite Australia’s climate history.
I am just waiting for blocks to be placed on Google Books and the National Library of Australia’s Trove, that allows us to look at newspaper items from 150 years ago, from Oz and around the world.
Then there is James Marusek’s documentation of the earth’s climate disasters, researched from independent sources – independent of the IPCC, the UN and the Melbourne University (and Tim Flannery).
The Domesday Book produced around 1086 documents economic activity at that time for the purposes of taxation. Wine production was an important activity in a number of places in SE England. In the parish I grew up in, in west Essex, wine production was the second largest economic activity by value.
According to the Gardian:
http://www.guardian.co.uk/science/2012/may/17/australasia-hottest-60-years-study
Dr Steven Phipps said:
“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,”.
No long term trends ? Metinks the models are flawed !
atarsinc;
Consider yourself corrected. As Steven said, you need to look at the methodologies, code, etc. Then you can make statements about their models’ validity. You haven’t shown that their models “ignore some natural factors”. JP
>>>>>>>>>>>>>>>>
I call bs.
A considerable portion of their study is based on tree rings, possibly the most discredited proxy there is. Using tree growth as a proxy for temperature ignores natural factors in spades, including (but not limited to)
rainfall
pestilence
disease
cloud cover variation
herbivore population
fertilization due to animal excrement
CO2 concentrations
competition (or lack thereof) from other plants
Tree rings as a proxy for temperature is a total load of animal excrement, male bovine to be specific. Once one sees those words in a “temperature reconstruction” the paper can safely be assumed to be bullarky.
Bernd Felsche, I think you misread something, those coordinates look fine to me.
Something, as an engineer, that always amazes me about these papers is the number of significant figures and the supposed accuracy of the data. Apart from in a laboratory, I cannot measure temperature to anywhere near 0.01C however they quote numerous trends and anomolies from hundreds of years ago to this sort of accuracy. They are single point measurements of a ‘proxy,’ for example a growth ring in a tree, laid down hundreds of years ago, and then infer a temperature to whatever accuracy they desire. This is not even possible with modern day measurements, but it doesn’t stop them.
sunshinehours1 says:
May 17, 2012 at 6:54 pm
“Only records that were significantly (p<0.05) correlated with the
226 detrended instrumental target over the 1921–1990 period were selected for analysis."
———————-
Isn't this the well known "Trick" to produce hockey sticks out of anything, even random numbers ?
@davidmhoffer:
Speaking of bulls and the excrement thereof… one of my favorite “issues” with tree rings (other than that an up-sun tree can fall over and rot and suddenly your tree starts making bigger rings) is the issue of, um, how to put it politely… “If a bear poos in the forrest, does it smell near a tree?”
A study of nitrogen cycles in the Pacific N.W. found that bears, catching salmon, tended to take some of them inland. Then when the, er, “urge”, came; they would deposit the ex-salmon near trees. The ‘bear deposits’ were a major part of the nitrogen “flux” into the forrest.
So for all those tree rings, we also need to know the annual salmon run sizes and any changes in bear population to calibrate the tree rings for “Bear Poo Nitrogen” levels…
And, one presumes, some amount of “Number One” nitrogen too…
@Alma Geddon:
Yes! I’ve raised that point some times and generally just taken grief for it. They think that because an average of a bunch of numbers can be known to very high precision that it means something. It doesn’t.
Yes, you can remove random error in measurments of the same thing that way. No, you can not remove systematic error that way (so, for example, shifting to ASOS and moving most readings to airports… ) Then they have the gall to think that averaging temperatures has some value anyway.
Temperature is an intrinsic property. They can not be averaged across different things.
My favorite simple example of this is mixing two pots of water. One at 0 C the other at 20 C. The “average of temperatures” will be exactly 10 C. What temperature is the water after mixing? You can not know. What were the relative sizes of the pots? Was the salinity and hardness the same? Was that 0 C water all melted, or all ice, or some of each? Ignoring enthalpy in a calorimetry experiment is a big problem… Constantly changing the thermometers around screws up calorimetry too (ask any chemist…)
IMHO, we can have no precision greater than the original 1 F of US Records. And that is for the instrumental record! Tree rings are worse.
Per the 1000 years and nothing changing like now:
I thought the exit from the last glacial was way faster? And what about the Younger Dryas wobble. It was supposed to be several degrees in one go. Or are they just trying to say the actual temperature has not been higher? If that’s the point, then what about the Roman Optimum? What about when the Sahara was green and lush about 6000 years BP? That only happens when it is warmer.
Further to contributor E M Smith’s comments, the classic is satellite sea level measurement. According to their own webpages (see the Ocean Reference pages on this site for links) they claim they can measure sea level with an accuracy of 30mm, however that does not stop them calculating and quoting sea level trends per annum to the nearest 10 microns, 0.01mm, that is, about one tenth the thickness of an average human hair. I would be hard pressed to measure the depth of my fish pond to an accuracy of 1 mm given capillary effects, the stirring of the water by wind and upset fish, etc, etc.
Why do you think they include 3000 methods- because noone could possibly read through and do analysis on all of it- there will be 2000 moderately legitimate methods near the beginning and 1000 hockey sticks and the hockey sticks will get 99.9% of the weighted result. If they were doing real science they would use one method which is fully justified and transparent unlike Mann’s hidden in unpublished unjustified code method
Is’nt one of the arguments against using Ice cores from greenland that it is a local record. But Australia can record will give us anyting meaningful!
The discriminatory axis must be what each record shows.
This paper seems to avoid cherry picking of hockey sticks with this step : “For predictor selection, both proxy climate and instrumental data were linearly detrended over the 1921–1990 period to avoid inflating the correlation coefficient due to the presence of the global warming signal present in the observed temperature record.”
A step that Mann would have done well to have used in his original hockey stick paper.
According to the Professor of the History of Science at the University of Cambridge Simon Schaffer, the new scientific paradigm consists of serving the cause of “progress” through instilling authority and trust and devising “stories that compel”:
http://www.bbc.co.uk/programmes/b01b1ljm
Dr Gergis’s results certainly neatly fit the narrative — a bit too neatly.
Still looking for the rise in temperatures here in the last 50 years…
…still looking
no, can’t find it…not here anyway.
Broome is 0.1C warmer in the last 70 years than the previous 50 years. That must be because the BoM measuring stuff was moved 1 mile to the airport…
Many of us, including we Australians, would be delighted if a credible, agreed proxy record could be assembled. The eternal arguments would hopefully stop.
We are still waiting for this nirvana.
There are 2 problems precedent to the writing of this paper.
First, the Australian measured temperature record is so poor that it it not a candidate for the calibration of proxies. Example – a few weeks ago the Bureau of Meteorology issued a new national high quality temperature set named Acorn-SAT, with adjustments that exceed 1 degree C compared with historic records. A preview of the present paper, in a sense, is at http://climatehistory.com.au/wp-content/uploads/2009/12/Neukom_and_Gergis_2011.pdf It does not mention use of Acorn-SAT.
Second, the temporal resolution of modern instrumental records exceeds that of proxy records 1,000 years old. While it is easy to average an instrumental temperature record over the last 50 years, a record from 1,000 years ago has no hopw of finding a 50-year resolution. The situation is similar to an oversmoothing. Therefore, the claim fails.
Espen,
Nothing mis-read, Misunderstood.
My planet only turns one way … apparently one can model it to turn the other way.
That confuddled my tiny engineering brain which is anchored to reality.