by Richard Threadgold
For the last ten years, visitors to NIWA’s official website have been greeted by a graph of the “seven-station series” (7SS), under the bold heading “New Zealand Temperature Record”. The graph covers the period from 1853 to the present, and is adorned by a prominent trend-line sloping sharply upwards. Accompanying text informs the world that “New Zealand has experienced a warming trend of approximately 0.9°C over the past 100 years.”
The 7SS has been updated and used in every monthly issue of NIWA’s “Climate Digest” since January 1993. Its 0.9°C (sometimes 1.0°C) of warming has appeared in the Australia/NZ Chapter of the IPCC’s 2001 and 2007 Assessment Reports. It has been offered as sworn evidence in countless tribunals and judicial enquiries, and provides the historical base for all of NIWA’s reports to both Central and Local Governments on climate science issues and future projections.
NIWA has a printed promotional brochure describing its climate activities, which commences with the iconic 7SS graph. No piece of climate lore is more familiar to the public, and it is better known than NIWA’s logo.
But now, para 7(a) of NIWA’s Statement of Defence states that “there is no ‘official’ or formal New Zealand Temperature Record”.