It is good news for improving accuracy in surface temperature readings. This article summarizes the errors in New Zealand's official historical temperature trend since the 1860's and indicates that corrections are likely in the works. This is good news for accuracy in climate research, perhaps one day the global trend can be considered reliable.
Crisis in New Zealand climatology
The problem:
The official archivist of New Zealand’s climate records, the National Institute of Water and Atmospheric Research (NIWA), offers top billing to its 147-year-old national mean temperature series (the “NIWA Seven-station Series” or NSS). This series shows that New Zealand experienced a twentieth-century warming trend of 0.92°C.
The official temperature record is wrong. The instrumental raw data correctly show that New Zealand average temperatures have remained remarkably steady at 12.6°C +/- 0.5°C for a century and a half. NIWA’s doctoring of that data is indefensible.
The reason it matters:
For nearly 15 years, the 20th-century warming trend of 0.92°C derived from the NSS has been at the centre of NIWA official advice to all tiers of New Zealand Government – Central, Regional and Local. It informs the NIWA climate model. It is used in sworn expert testimony in Environment Court hearings. Its dramatic graph graces the front page of NIWA’s printed brochures and its website.
Internationally, the NSS 0.92°C trend is a foundation stone for the Australia-New Zealand Chapter in the IPCC’s Third and Fourth Assessment Reports. In 1994, it was submitted to HadleyCRUT, so as to influence the vast expanses of the South Pacific in the calculation of globally-averaged temperatures.