Brian Rudman: Exercise degrees of common sense

At least three city councils have had their weather recording stations moved. Photo / APN

The flat-earthers from the New Zealand Climate Science Coalition are off to the High Court to try to persuade a judge to invalidate the country's official temperature record compiled and collected by the Government-owned National Institute of Water and Atmospheric Research.

As devout deniers of man-made global warming, the coalition claims the only way Niwa can claim a warming trend of 1C over the past century is by cooking the books.

Unfortunately for them, in citing the records of another Crown company, the MetService, to help back up their wild allegations, the deniers have done themselves no favours.

In a press release coinciding with their trip to the High Court to file papers, the coalition claims "The NZ MetService record shows no warming during the last century."

The joke is that in February 2002, I had some fun at the MetService's expense, revealing that for $100,000 it would happily shift a weather station anywhere a mayor requested in order to improve his or her town's temperature on the nightly television weather spot. And who did I find to criticise this sleight of hand but none other than the deniers' bete noir, Jim Salinger, then a senior scientist at Niwa.

My investigations had been sparked by a reader noting that Wellington seemed to share Auckland's temperature on the telly each night, which we all knew couldn't be true.

It turned out that Mark Blumsky, the capital's mayor from 1995 to 2001, became unhappy with the low temperatures reported from the traditional weather recording stations at Wellington airport, the Kelburn hills and Lower Hutt and demanded MetService find a warmer spot.

MetService said name your spot, and as long as it meets certain guidelines such as being over grass, and the mayor paid $100,000 in set-up costs, that would be it.

Which is how the sheltered lawn in front of the Michael Fowler Centre became a new MetService weather station, and Wellington's daily temperature on the telly suddenly increased by about 1.5C.

Mayor Blumsky wasn't alone. New Plymouth and Hastings City Councils also paid for new sites around that time. Dr Salinger frowned on this as "temperature for tourism" and said Niwa saw monitoring as a long-term affair, going out of its way to record from sites unaffected by urban influence.

Last November, the deniers claimed that in preparing long-term trend charts, Niwa had adjusted early temperature readings from seven weather sites around the country with 100-year records, reducing some by up to 1.3C to create a "false warming" graph up to the present day.

Niwa's principal climate scientist, James Renwick, explained there were several reasons for adjusting the temperature record, including introducing new thermometers or sensors to a weather site and changes to its exposure caused by growing vegetation or urbanisation.

In Wellington until the mid-1920s, for example, temperatures were recorded near sea-level at Thorndon. Then the recording station moved to cooler Kelburn, about 120m above sea level. To make an accurate comparison, the Thorndon figures were reduced by the average temperature difference of the two sites, 0.96 degrees. Similar adjustments were made from the records from other sites so that like could be compared with like.

I'm no scientist, but this explanation seems common sense to me and, I suspect, to everyone but those on the fringes who believe the majority of world climate scientists are involved in some giant global conspiracy.

The coalition isn't the first to try to fight global warming in the courts. In September 2008, Queenstown property developer Basil Walker tried unsuccessfully to get an injunction against the Labour Government's Emissions Trading Scheme becoming law.

Arguing against "the theory of global warming", he filed Act MP Muriel Newman's article "Exposing the Climate Change Agenda" as part of his supporting evidence. Justice Denis Clifford threw the application out as unconstitutional.

The image of the flat-earthers in court making fools of themselves, trying to prove that if you travel to the horizon you'll fall off into oblivion, is rather appealing. But court proceedings are ruinously expensive, and while the mystery money-bags funding the coalition - Act Party supporters are mentioned - may be able to afford it, taxpayers cannot.

Yet we are the ones who will have to fund Niwa's day in court defending itself against this attention-seeking stunt of the deniers.

Several prominent scientists have attacked the move, saying the place for scientific debate is in peer-reviewed journals, not court rooms.

They've challenged the coalition to submit a paper backing its claims, and be judged publicly by the quality of their scientific argument.

But this challenge has been made before and remains unanswered. For obvious reasons.

They might feel they have a chance of bamboozling a judge and the court reporters with their conspiracies, but know only too well the mockery they face from the editorial team of a reputable science publication.