Skip to content

Stephen McIntyre: Oxburgh’s Trick to Hide the Trick

The Oxburgh report ” is a flimsy and embarrassing 5-pages.

They did not interview me (nor, to my knowledge, any other CRU critics or targets). The committee was announced on March 22 and their “report” is dated April 12 – three weeks end to end – less time than even the Parliamentary Committee. They took no evidence. Their list of references is 11 CRU papers, five on tree rings, six on CRUTEM. Notably missing from the “sample” are their 1000-year reconstructions: Jones et al 1998, Mann and Jones 2003, Jones and Mann 2004, etc.)

They did not discuss specifically discuss or report on any of the incidents of arbitrary adjustment (“bodging”), cherry picking and deletion of adverse data, mentioned in my submissions to the Science and Technology Committee and the Muir Russell Committee. I’ll report on these issues later in the day as they’ll take a little time to review. First, let’s observe Oxburgh’s trick to hide the “trick”.

Long before Climategate, Climate Audit readers knew that you had to watch the pea under the thimble whenever you’re dealing with the Team. This is true with Oxburgh of Globe International as well.

Oxburgh of Globe International alludes to the “ hide the decline” in veiled terms as follows:

CRU publications repeatedly emphasize the discrepancy between instrumental and tree-based proxy reconstructions of temperature during the late 20th century, but presentations of this work by the IPCC and others have sometimes neglected to highlight this issue. While we find this regrettable, we could find no such fault with the peer-reviewed papers we examined.


Without specifically mentioning the famous “trick …to hide the decline”, Oxburgh subsumes the “trick” as “regrettable” “neglect” by “IPCC and others”.

But watch the pea under Oxburgh’s thimble.

The Oxburgh Report regrettably neglected to highlight the fact that CRU scientists Briffa and Jones, together with Michael Mann, were the IPCC authors responsible for this “regrettable neglect” in the Third Assessment Report. They also regrettably neglected to report that CRU scientist Briffa was the IPCC author responsible for the corresponding section in AR4.

Oxburgh pretends that the fault lay with “IPCC and others”, but this pretence is itself a trick. CRU was up to its elbows in the relevant IPCC presentations that “regrettably” “neglected” to show the divergent data in their graphics.

It is also untrue that CRU authors, in their capacity as IPCC authors, “regrettably” “neglected” to show the divergent data in the IPCC graphics. The Climategate emails show that they did so intentionally – see for example IPCC and the Trick, which show awareness on the part of CRU scientists that showing the decline would “dilute the message” that IPCC wanted to send. The eventual IPCC figure, as reported here on a number of cases, gave a false rhetorical message of the veracity of the proxy reconstructions.

CA readers are also well aware that IPCC and Briffa were categorically asked by one AR4 reviewer (me) to disclose the divergent data. CRU’s Briffa refused, saying only that it would be “inappropriate” to show the data in the graphic. They didn’t “neglect” to show the divergent data from the Briffa reconstruction. This was a considered decision, carried out in AR4 despite pointed criticism.

Yes, the decline had been disclosed in the “peer reviewed literature”. Indeed, that was how I became aware of the trick – long before Climategate and why, as an AR4 peer reviewer, I asked that IPCC not use the trick once again in AR4.

IPCC presentations are how the climate science community speaks to the world. Climate scientists, including CRU scientists, have a far greater obligation of full, true and plain disclosure in IPCC reports than even the specialist literature. Oxburgh pretends that (partial) disclosure of adverse results by CRU in specialist literature is sufficient. It isn’t. There was a continuing obligation to disclose adverse results in IPCC graphics.

CRU scientists acted as IPCC authors. The complaint about the trick arose out of how CRU scientists carried out their duties as IPCC authors.

In this respect, the Oxburgh report is a feeble sleight-of-hand that in effect tries to make the public think that the “trick” was no more than “regrettable” “neglect” by the “IPCC and others” – nothing to do with CRU. In other words, Oxburgh is using a trick to hide the “trick”.

Trick me once, shame on you.

Update 9.40 am. The Daily Telegraph reports:

Professor Hand did say that “inappropriate methods” were used by a separate university to draw up the infamous “hockey stick” graph showing the rise in global temperatures over more than 1,000 years.

Uh, memo to Oxburgh. CRU produced its own hockey stick graphs in Jones et al 1998, Mann and Jones 2003, for example. For some reason, Oxburgh and his associates regrettably neglected to consider these articles.

Climate Audit, 14 April 2010