It was a great disappointment that Justice Venning was not prepared to declare NIWA’s data adjustments to be a breach of the Crown Research Institutes Act 1992.
On the law, the Judge found that any review should be “tolerant” and “cautious” because NIWA was “a specialist body acting within its own sphere of expertise.” He declined to rule on the disputed science – while tending to favour the 92-page opinion evidence provided by NIWA’s Dr Wratt (which was not subject to cross-examination).
Where does this now leave the NZCSC’s long-term effort to show that the NIWA temperature adjustments are wrong?
Following is a list of the “key facts” which underpinned the plaintiff’s case:
- The temperature data collected from weather stations throughout New Zealand show no or a minimal warming trend over the last century.
- The Seven Station Temperature Series (7SS) published by NIWA on its website as part of the New Zealand temperature record shows a warming trend of approximately 0.9°C per century during the period 1909-2008.
- The warming trend is the result of NIWA adjustments made to the pre-1945 raw temperature data to eliminate the effects of site changes. The adjustments involve the use of comparative data from neighbouring stations.
- The internationally-recognised statistical method for making neighbour-station-comparison adjustments was set out in a peer-reviewed paper authored by Drs Rhoades and Salinger published in the International Journal of Climatology in 1993 (RS93).
- Although the 7SS graph has appeared on NIWA’s website since 1999, all pre-2009 records of its composition and calculation have disappeared. Prompted by the NZCSC, NIWA reconstructed a Schedule of Adjustments in February 2010 and published a revised version in December 2010.
- The 7SS adjustments are not taken from RS93. The statistical comparison techniques are those set out in a PhD thesis completed by Dr Jim Salinger in 1981 (the Thesis). The calculations for the Thesis were lost in a 1983 computer mishap.
- No peer-reviewed literature supports the statistical comparison techniques used for the revised 7SS, and none is mentioned in the 170-page Review document. No reason was offered in the Review document, or the Wratt evidence or elsewhere for the departures from the world-practice RS93 method.
- If the data from the stations making up the 7SS were adjusted in accordance with RS93 the resulting warming trend would be materially different from that generated by the outdated Thesis method. According to the NZCSC ‘Audit’ paper a strict application of RS93 would produce a trend of only 0.34°C/century.
- NIWA is unperturbed that the 7SS adjustments show an unusual linear bias in a warming direction, or that their trends contradict earlier nationally-averaged studies. This is based on a theory that early weather stations migrated systematically from the centre of towns to the outskirts. (The maps in the 2010 ‘Review’ show otherwise).
- NIWA asserts that it is not required to justify its methods. It claims the exclusive and untrammelled right to select any statistical technique it thinks appropriate. However, it publicly undertook to have its methods tested by both a BoM review and the independent peer-review of a scientific journal. It has now elected to neither disclose nor rely upon BoM’s work and it has not submitted to a journal review.
- Contrary to the authority of RS93 and Hessell (1980) both the original and revised versions of the 7SS use data which is, or might be, contaminated by shelter. This affects Auckland, Wellington, Lincoln and Nelson. NIWA accepts that contamination has probably occurred at Auckland and Lincoln, but has declined to exclude those stations from the 7SS.
- NIWA bases its decisions regarding the temperature record on both the 7SS and an Eleven-Station Series (11SS) constructed by Dr Salinger in 2009. The 11SS covers the period 1955-1984 but has been artificially extended back to 1931, in an apparent effort to maximise its warming trend. If this extension were omitted the series would show a trend of only 0.28°C/century (DW215). Despite significant site changes, the 11SS is unadjusted. The 11SS also ignores WMO tolerances for missing data, both monthly and annual.
None of these statements were refuted in the Wratt evidence or even seriously questioned by defence counsel. None of them were found to be incorrect by the Court.
There were also two other factual allegations worth mentioning which NIWA did dispute:
The Court made no definitive decision on these two important allegations, considering them to be based on issues which were the subject of scientific dispute. I’ll deal with them in a separate article.
The inarguable position described in 1-8 above is wholly unsatisfactory. I still believe it is so extreme as to be illegal, and will be conferring with counsel regarding the prospects of an appeal against Justice Venning’s decision.
Even if the above key facts are not a breach of the law, they are certainly a breach of both scientific conventions and common sense. No policymaker should be asked to rely upon data which has been manipulated by unprecedented DIY techniques – especially when those methods have failed to pass peer review.
Both NIWA and BoM (at NIWA’s request) declined freedom-of-information requests for copies of the BoM report. Early last year, appeals were lodged to the respective authorities in New Zealand and Australia. NIWA advised the Ombudsman that the BoM report was relied upon for the litigation – and then advised the Court that it did not rely upon any aspect of the BoM review. We will pursue this.
Minister Wayne Mapp advised Parliament that a journal paper describing NIWA’s adjustment techniques would be submitted by June 2011. The Court was told that the paper was delayed because of the litigation. No new target date has been announced.
The Minister further undertook that statistical confidence levels for the adjustments used in the 7SS would be published. The review document confirms this work was under way in 2010, but the Wratt affidavit says the figures will not be released until the journal paper appears.
Guided by Network PR and a bevy of barristers, NIWA has so far proved remarkably adept at dodging the bullets their adjustments deserve. But well-honed skills in ducking and weaving do nothing to erase the widespread impression that these publicly-funded scientists are accountable to nobody!