While Dr. Mann and his attorneys are busy sending letters to threaten legal action against authors of a parody video depicting him chopping down trees, such as this one he hasn’t gotten to yet, Steve McIntyre points out that Dr. Mann has a bigger problem. Oak Trees were found in his paper Mann 2008 et al, which was touted as his “do over” of the original MBH98 hockey stick in response to critics. With this revelation, Sudden Oak Death appears to have afflicted the “robustness” of the paper.
Steve McIntyre writes:
Doug Keenan has received a favorable decision from the FOI Commissioner in his lengthy FOI/EIR battle for tree ring data collected by Mike Baillie of Queen’s University, Belfast. The data is from Irish oaks and was collected mostly in the 1970s. The decision has been covered by the Times, the New Scientist and the Guardian and at Bishop Hill here and here.
Responses to the decision from Baillie, Rob Wilson and Phil Willis are as interesting as the decision. Baillie and Wilson argued that oak chronologies were “virtually useless” as temperature proxies and “dangerous” in a temperature reconstruction. Nonetheless, as I report below, no fewer than 119 oak chronologies (including 3 Baillie chronologies) were used in Mann et al 2008 without any complaint by Wilson or other specialists. CA readers will also be interested in Baillie’s 2005 response to a Climate Audit post urging climate scientists to update the proxies.
Oak as a Temperature Proxy
The scientist who had been withholding the data, Michael Baillie, ridiculed the idea that his Irish oak data was relevant to temperature reconstructions, saying that it would be “dangerous” to use this data for reconstructing temperature. Hannah Devlin of The Times:
However, the lead scientist involved, Michael Bailee, said that the oak ring data requested was not relevant to temperature reconstruction records.
Although ancient oaks could give an indication of one-off dramatic climatic events, such as droughts, they were not useful as a temperature proxy because they were highly sensitive to water availability as well as past temperatures, he added.
“It’s been dressed up as though we are suppressing climate data, but we have never produced climate records from our tree rings,” Professor Bailee said.
“In my view it would be dangerous to try and make interpretations about the temperature from this data.”
Baillie made a similar statement to the Guardian:
“Keenan is the only person in the world claiming that our oak-ring patterns are temperature records,” Baillie told the Guardian.
Rob Wilson agreed with Baillie on this point, telling the Times that “oaks were virtually useless as a temperature proxy”.
Mann et al 2008
Notwithstanding the considered opinion of Baillie and Wilson that oaks are “virtually useless as a temperature proxy” and “dangerous” to use in a temperature reconstruction, no fewer than 119 oak chronologies were used in Mann et al 2008.
Among Mann’s oak chronologies were three Baillie chronologies: brit008 – Lockwood; brit042 – Shanes Castle, Northern Ireland; brit044 – Castle Coole, Northern Ireland.
Far be it from me to disagree with the specialist view of Wilson and Baillie that these oak chronologies are “virtually useless” as a temperature or “dangerous” to use in a temperature reconstruction.
However, surely it would have been far more relevant for them to speak up at the time of the publication of Mann et al 2008 and to have expressed this view as a comment on that publication. At the time, Climate Audit urged specialists to speak out against known misuse of proxies, but they refused to do so. (see Silence of the Lambs).
More here at Climate Audit
Kinda puts a death knell on the entire paper when another tree ring specialist argues vehemently that oak trees are “virtually useless” for temperature and then we see that Mann used the very same oak tree data the scientist was arguing against releasing, because it would “dangerous” to use it as a temperature proxy.
Dr. Mann has bigger credibility problems to worry about than parody videos.
As I’ve written before, the whole premise of treemometers is not without its problems: