David Sapiane (11 March) uses my 25 February letter, which offered to provide scientific proof of man-made global warming, to cast serious doubt on the degree of warming and whether, in New Zealand's case, it actually exists at all. He seriously questions the reliability of the methods universally adopted to standardise the readings and points out there is a law suit in NZ regarding whether NIWA have adjusted their temperature data correctly.
Not being personally familiar with the methods used to standardise the data, I can only question the motives of those seeking the judgement of a law court to settle a scientific argument. How, for instance, can the great majority of glaciers on every land mass (including NZ) and the edges of vast ice sheets in Greenland and Antarctica be collapsing, Arctic sea ice disappearing, permafrost melting, global sea temperatures rising, coral reefs bleaching, and growing seasons in high and mid latitude regions be lengthening, all without a significant rise in average global temperatures? Perhaps their lawyers can explain this where their scientific advisors have failed?
I suspect the sceptics hope that, if lawyers can quibble over the precise degree temperature change, they can throw another spanner in the works and further undermine public resolve to commit to essential emissions cuts.
Peter Otway, Pahoia.