Revkin on the Gergis et al 'on hold' affair

I promised Andrew Revkin yesterday that I’d give his post on Gergis et all some attention, because he’s done a good job of summarizing it all, plus getting some other angles, such as that of Retractionwatch. I was especially pleased to note that he reports that the blogosphere is becoming increasingly important as a tool of peer review. Unlike The Team, David Karoly had the good sense to at least acknowledge McIntyre’s contributions. Below is an excerpt of Revkin’s article. – Anthony

Australian Warming, Hockey Sticks and Open Review

By ANDREW C. REVKIN

A much-cited study (paper here) concluded last month that the extent of warming in Australia in recent decades was so great compared to climate variations in the last millennium that it had to be mainly the result of warming from the human-driven buildup of greenhouse gases in the atmosphere. (Here’s a video interview from May with the lead author, Joëlle Gergis from the University of Melbourne.)

It’s the latest research in more than a decade of work producing a climate “hockey stick” — graphs of global or regional temperatures showing relatively little variation over a millennium or more and then a sharp uptick since the middle of the twentieth century (the blade at the end of the stick).

Now the paper, at the request of the authors, has been “put on hold” by the Journal of Climate after questions were raised publicly about one of the researchers’ methods, starting with a comment on Steve McIntyre’s Climate Audit blog. This field of study uses sophisticated statistical methods to derive meaning from scattered and variegated indirect indicators of past temperature — with tree rings being the most familiar example.

It is unclear whether the problem will affect the study’s conclusions. Depending on the result, readers of the initial burst of news could end up with a familiar sense of whiplash.

To see how quickly the research results made the rounds, check the headlines here. My unfavorite would be “IT’S OFFICIAL: Australia is warming and it is your fault,” in the Herald Sun. This is a classic case of what I’ve been calling “single-study syndrome,” the bias in the news process toward the “front-page thought” and tendency to forget that science is a herky-jerky process.

Over the weekend, I got in touch with David Karoly, one of the paper’s authors … who wrote:

As I said in my e-mail to Stephen, “This is a normal part of science. The testing of scientific studies through independent analysis of data and methods strengthens the conclusions. In this study, an issue has been identified and the results are being re-checked.”

Indeed, this is an increasingly normal part of science these days. While the blogosphere comes with lots of noise, it also is providing a second level of review — after the initial round of closed peer review during the publication process — that in the end is making tough, emerging fields of science better than they would otherwise be.

Read the full article here, well worth your time for the additional comments Revkin included from others.

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Steve McIntyre also has some additional thoughts in a new post yesterday: More on Screening in Gergis et al 2012. The first section reads:

First, let’s give Gergis, Karoly and coauthors some props for conceding that there was a problem with their article and trying to fix it. Think of the things that they didn’t do. They didn’t arrange for a realclimate hit piece, sneering at the critics and saying Nyah, nyah,

what about the hockey stick that Oerlemans derived from glacier retreat since 1600?… How about Osborn and Briffa’s results which were robust even when you removed any three of the records?

Karoly recognized that the invocation of other Hockey Sticks was irrelevant to the specific criticism of his paper and did not bother with the realclimate juvenilia that has done so much to erode the public reputation of climate scientists. Good for him.

Nor did he simply deny the obvious, as Mann, Gavin Schmidt and so many others have done with something as simple as Mann’s use of the contaminated portion of Tiljander sediments according to “objective criteria”. The upside-down Tiljander controversy lingers on, tarnishing the reputation of the community that seems unequal to the challenge of a point that a high school student can understand.

Nor did they assert the errors didn’t “matter” and challenge the critics to produce their own results (while simultaneously withholding data.) Karoly properly recognized that the re-calculation obligations rested with the proponents, not the critics.

I do not believe that they “independently” discovered their error or that they properly acknowledged Climate Audit in their public statements or even in Karoly’s email. But even though Karoly’s email was half-hearted, he was courteous enough to notify me of events. Good for him. I suspect that some people on the Team would have opposed even this.

McIntyre goes on to explain the “screening fallacy” (or the cherry pick if you will) in detail.

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slow to follow
June 12, 2012 6:32 pm

handjive – Not sure that is anything more than a rehash of the email to Steve. The timing of the email to the Journal, however, could settle it in Karoly’s favour if he felt it important to evidence his prior art claim.

Werner Brozek
June 12, 2012 6:52 pm

Noah’s ark was built by amateurs. The titanic was built by professionals.

Werner Brozek
June 12, 2012 7:15 pm

handjive says:
June 12, 2012 at 4:48 pm
“Professor Karoly said the authors uncovered the problem before Climate Audit blogged about it.”
However was the playing field level? Based on this quote, it was not:
“Joelle Gergis has responded blowing off my request (cc to David Karoly, Valeria Masson-Delmotte (AR5 CLA) and the editor of Journal of Climate). She says that I should try to get the unarchived data from the original authors, saying snottily that this is “commonly called ‘research’” and that they “will not be entertaining further correspondence” on the matter.”
So the other group obviously had the data right away.

davidmhoffer
June 12, 2012 9:11 pm

Uhm…. which peer review process does Phil C subscribe to?
The traditional journal methodology or the new improved Phil Jones methodology?

Tom Harley
June 12, 2012 9:24 pm

Hilary, you nailed it, well said…

just some guy
June 12, 2012 9:36 pm

An interesting exchange on RealClimate:

Salamano says:
12 Jun 2012 at 12:57 PM
I’ve got a question for the dendro-folks…It’s probably already discussed in a paper I can be pointed to.
In other sampling-type studies, a certain number needs to be taken so that the power of the sample can accurately describe the whole with a manageable margin of error. Does this sort of thing not play a role at all in dendrochronology after selecting a site a priori for its determined ability to signal global temperature (ie, ‘treeline’, etc.)?
I’m just thinking there are hundreds of thousands of trees in a region, and the cores per site can be 20-30. I’m assuming since that’s not enough to be representative of the whole that there’s got to be a set of arguments why:
(a) out of an entire population of, say 10,000 trees, 10 cores out of 20-30 are said to effectively model the instrumental temperature record (regardless of what they display in other eras), and have that be certainly NOT a product of chance, but rather a lead-pipe lock that it is describing the signal, or
[Response:Why you say “10 cores out of 20-30” I don’t know, because all the cores of a site, not just some fraction thereof, are used to provide the climate signal of interest. But to your point specifically: please point me to any verbal concept, any algorithm, any model code, ANY WAY in which a stochastic process can lead the types of high inter-series (between cores) correlations typically seen in the tree ring data archived at the ITRDB. Just go there and start randomly looking at the mean interseries correlations documented in the COFECHA output files of each site, and tell me just how you would generate such high numbers with any type of stochastic process that’s not in fact related to climate. And then how you would, on top of that, further relate the mean chronology of those sites to local temperature data at the levels documented in a wide range of public studies.–Jim]
(b) that it doesn’t matter how many trees exist in a region, nor how many cores are taken relative to the total number of trees– it’s simply about discovering any individual trees that evidence the temperature signal and discovering as many co-located as possible. It doesn’t matter how many there are, but instead how well they match the signal.
[Response:At the risk of having this statement completely misunderstood and mangled by the usual suspects…if you only had one tree out of 10K that responded well to temperature, and you found and cored that one tree, you would have legitimate evidence of a temperature signal. Fortunately, the situation is nowhere remotely so extreme as that, and that’s because, in fact, that many trees respond in this way, and therefore you only need some couple dozen or similar to get a signal that emerges strongly from the noise at any given location. And why do many trees respond this way? Because, lo and behold….temperature is a fundamental determinant of tree radial growth in general, i.e. a fundamental tenet of tree biology.–Jim]
104
Ray Ladbury says:
12 Jun 2012 at 8:03 PM
Salamano,
OK, there are thousands of trees. However, if the same physical conditions persist over the entire range, then trees of a particular species ought to respond in a comparable fashion, no? And remember, the time series consists of rings for a single individual. You are looking at multiple time series to average out extraneous effects–e.g. microclimate.
a layman says:
Your comment is awaiting moderation.
12 Jun 2012 at 11:28 PM
“…if you only had one tree out of 10K that responded well to temperature”
But how do you know that one tree is not just more noise, which by coincedence just happens to match roughly to 20th century temperatures? You have not answered this question.
(expecting the typical blockage of comments you don’t like, a response would still be nice, nonetheless…)

My attempted comment is “a layman” and I’ve had multiple attempts to post simple questions blocked by the moderators there.

June 12, 2012 10:17 pm

Upon reading Mr. Revkin’s analysis I find myself of hope for the change that is needed. Cognizance of the value of science, however messy some science turns out to be, because, in the end-game, we would all rather know what there really is to know. If there is an AGW effect it remains to be seen if this can truly be distinguished from potentially the normal wobbly end of the most recent extreme interglacial.
Unfortunately, in that same end-game, we must navigate where we are intellectually and ethically. Steve McIntyre provided the intellectual challenge. Andrew Revkin evaluated this and stepped up to the ethical plate. He is also correct. The blogosphere does indeed provide value. Perhaps enough to provide limits to the flexibility of ethics.
As the sun goes all quiet on us, at the half-precession old Holocene, strong, from 1 to 3 thermal pulses being the norm, there is the possibility that we do indeed need to carefully ponder when we live.

Jessie
June 13, 2012 3:02 am

CLIMATE PAPER FLAWED
Bernard Lane, The Australian June 13, 2012 12:00AM
A PIONEERING paper on climate change has been put on hold after a mix-up in its methodology was identified.
The study, published online last month by the US-based Journal of Climate, was led by a University of Melbourne scientist Joelle Gergis at the head of a 30-strong international team.
It was reported as the first large-scale reconstruction of Australasian climate and confirmation that the period since 1951 has been the warmest in 1000 years, an outcome consistent with an increase in greenhouse gases.
The results are to be the Australasian region’s contribution to an Intergovernmental Panel on Climate Change report on past climate.
But print publication has been put on hold after one of the authors discovered that the paper wrongly described how the data had been processed, according to team member David Karoly, professor of meteorology at Melbourne.
He said this was picked up when team members were responding to requests for more data, including from a website set up by Canadian mining consultant Steve McIntyre with the stated aim to “audit” the results of climate change studies.
[SNIP: Jessie, “fair use” allows us to print part of published work but not the whole thing. -REP]
source: http://www.theaustralian.com.au/higher-education/climate-paper-flawed/story-e6frgcjx-1226393519781