NIWA’s maverick methodology

maverick

A sober analysis from an indefatigable leader of our Campaign for True Temperatures. Barry’s careful, professional reticence stands in stark contrast to the concerns emerging over the work of our premier climate institution. — Richard Treadgold


“NIWA uses internationally accepted techniques” — Hon Dr Wayne Mapp, Minister of Research, Science and Technology.

The principal methodology used by NIWA in calculating adjustments to historical data for both the Seven-station Series (7SS) and its provisional replacement, the New Zealand Temperature Seven (NZT7), is by comparison with other temperature stations. This is well explained in the Review Report published December 2010 (page 11) as follows:

  • Micro-climates exist: Within a general region, taking Wellington as an example, there are many micro-climates, and thus temperatures vary from place to place. This is because of Wellington’s varied topography, meaning that the sites have different exposures and aspects and are at different altitudes. All these factors can influence the measured temperature. There is no such thing, therefore, as “the” Wellington temperature; there are many Wellington temperatures, and they are all different.
  • Neighbouring sites vary together: Comparison of temperatures from neighbouring sites shows again and again that trends and interannual variations at nearby sites are very similar. So although the base level temperatures may be different at two sites (due to micro-climate effects), the variations are almost in ‘lock-step’, with occasional exceptions. (See examples in the seven-station documents and on the NIWA website).

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