AGW law: New Zealand judgement day

In his Judgement Venning J. allowed the challenge in principle because NIWA was a Crown research Institute [CRI] and no other method of challenging it was available. In effect while Venning J. agreed the NZTR was not a public record [paragraph 38] the Public had a right to challenge actions of NIWA such as producing a NZTR.

However Venning J. dismissed that right to challenge on the basis of criteria outlined at paragraph 47 of his Judgement:

I consider that unless the Trust can point to some defect in NIWA's decision-making process or show that the decision was clearly wrong in principle or in law, this Court will not intervene. This Court should not seek to determine or resolve scientific questions demanding the evaluation of contentious expert opinion.

The error "in principle or in law" which the Trust tried to establish was that NIWA did not adjust temperature according to its own criteria as described in RS93.

NIWA's own expert witnesses admitted that they did not follow the RS93 criteria in a 2010 "Review" of the NZTR [paragraph 147] but had done so in forming the original NZTR which had been changed in 2009 from a 7 site network into an 11 site network which in turn was reviewed on the basis of other unspecified criteria for adjusting the raw data.

NIWA's expert witnesses stated it did not matter what criteria they used to adjust the raw temperature data or from what sites they adjusted the data from because the temperature trend results were the same as the trend produced by the RS93 adjustment criteria [paragraphs 148-149].

To double check that the alternative method[s] of adjusting the raw temperature data produced the same temperature trend as the RS93 criteria for adjusting would have done if used in the 2010 "Review" NIWA's experts did apply RS93 to the 2010 Review of the NZTR sites [paragraph 144]. The NIWA experts concluded that the Trust expert witnesses had been incorrect when they applied RS93 to the raw data and found a lesser trend then found by NIWA when it applied both RS93 and the other adjustment criteria.

This thoroughness by NIWA in checking its own adjustment procedures was approved by Venning J. who concluded at paragraph 157:

I accept that NIWA could have recalculated the temperature adjustments in a different way yet still have arrived at a similar result which would strengthen the robustness and validity of the previous results.

Venning J. could do nothing other than accept the statements of the NIWA experts because earlier he had dismissed the expertise of the Trust witnesses [paragraphs 49-54].

However, in accepting that NIWA could produce the official trend of 0.91C from different adjustment methods Venning J. provided legal interpretation of two principles of the AGW debate.

The first is that experts working for government or 'official' scientific institutions [CRIs] are given greater evidentiary weight then witnesses not working for CRIs. On this basis the authority of the AGW science has been judicially endorsed.