NIWA generating warmth

NIWA temperature adjustments, before and after

— by Barry Brill, Chairman of the New Zealand Climate Science Coalition

This graph summarises how NIWA’s recent adjustments to the historical temperature data has created a 20th century warming trend of 1.0°C. There were 22 changes in the period 1900-75 and almost all of those adjustments went downwards. Over 90% of the adjusted station-years moved in the same direction – a very surprising result.

Another curious aspect of the NIWA adjustments is that their amplitude is almost directly proportional to their chronological age. The further back one goes from 1975, the larger the adjustment becomes. Continue Reading →