Here’s how RealClimate.org summarized the findings of the original paper, which was published in mid-May:
The conclusion reached is that summer temperatures in the post-1950 period were warmer than anything else in the last 1000 years at high confidence, and in the last ~400 years at very high confidence.
The page at the American Metereological Society site where the paper used to be now reads:
The requested article is not currently available on this site.
The study was apparently first questioned by Steve McIntyre on the climate change skeptic site Climate Audit on May 31 (second half of post). On Friday, June 8, McIntyre reported that the study had been put “on hold” and published this email from co-author David Karoly:
I am contacting you on behalf of all the authors of the Gergis et al (2012) study ‘Evidence of unusual late 20th century warming from an Australasian temperature reconstruction spanning the last millennium’
An issue has been identified in the processing of the data used in the study, which may affect the results. While the paper states that “both proxy climate and instrumental data were linearly detrended over the 1921–1990 period”, we discovered on Tuesday 5 June that the records used in the final analysis were not detrended for proxy selection, making this statement incorrect. Although this is an unfortunate data processing issue, it is likely to have implications for the results reported in the study. The journal has been contacted and the publication of the study has been put on hold.
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.
We would be grateful if you would post the notice below on your ClimateAudit web site.
We would like to thank you and the participants at the ClimateAudit blog for your scrutiny of our study, which also identified this data processing issue.
Thanks, David Karoly
Print publication of scientific study put on hold
An issue has been identified in the processing of the data used in the study, “Evidence of unusual late 20th century warming from an Australasian temperature reconstruction spanning the last millennium” by Joelle Gergis, Raphael Neukom, Stephen Phipps, Ailie Gallant and David Karoly, accepted for publication in the Journal of Climate.
We are currently reviewing the data and results.
We contacted Karoly to find out how long the team expects the review to take, and whether this analysis has been used to inform other work before it was published. We’ll update with anything we hear back.
Post-publication peer review is indeed a “normal part of science,” as Karoly notes, and one that we’ve championed. While we’ll have to wait for the final outcome in this case, the authors should be commended for acting swiftly to try to correct the record. We’d only remind them, and the journal, that a publication is a publication, whether it’s online or in print, so if this paper turns out to be fatally flawed, it would need to be retracted and not simply disappear.
Despite the often contentious debates that erupt over climate change science, we’ve seen only one other retraction in the field since we launched in August 2010, when Edward Wegman was forced to retract a paper for plagiarism.
Update, 5 p.m. Eastern, 6/12/12: Karoly wrote us to confirm the that the the status of the paper is what Journal of Climate editor TK Broccoli told Steve McIntyre below: “…removed from a preprint server for accepted manuscripts that have not yet been published.” Karoly wrote:
The paper has been put on hold, while an issue with the data processing and methods that we have identified is checked. The paper has not been withdrawn nor has it been retracted.
We are reprocessing the data and double-checking everything. This will take some time. We expect to re-submit the revised manuscript to the Journal of Climate by the end of July and this will then be sent out for peer review again.
Hat tips: Warrick Nelson, Andre van Delft, Skiphil