NZ temps: warming real, record robust, sceptics wrong

By Gareth Renowden 02/12/2009

The National Institute for Water and Atmospheric Research (NIWA), accused last week of fiddling the long term New Zealand temperature record to create spurious warming, has released information showing that the attack mounted by the NZ Climate “Science” Coalition and Climate Conversation Group has no merit.

The NIWA announcement shows that the warming trend in the long term record is also found when weather stations with long term records that require no corrections are used. From the release:

Dr Jim Salinger has identified from the NIWA climate archive a set of 11 stations with long records where there have been no significant site changes. When the annual temperatures from all of these sites are averaged to form a temperature series for New Zealand, the best-fit linear trend is a warming of 1°C from 1931 to 2008. We will be placing more information about this on the web later this week.

I’ll have more detail on that series when it’s made available. So the warming in the record is robust, found in sites all round New Zealand, and doesn’t depend on mysterious adjustments. But the Treadgold/CSC report also made claims about data being hidden:

Requests for this information from Dr Salinger himself over the years, by different scientists, have long gone unanswered, but now we might discover the truth.

That’s an outright lie, as the NIWA release shows.

For more than two years, New Zealand Climate Science Coalition members have known of the need to adjust the ’seven station’ data. They have had access to:

  • the raw data
  • the adjusted data (anomalies)
  • information needed to identify the adjustments made by Dr Salinger
  • information needed to develop their own adjustments.

The NIWA release cites emails to CSC members Vincent Grey and Warwick Hughes in July 2006, which provided all the references required to calculate the necessary adjustments themselves. In particular, all the information about the station site changes has been publicly available since 1992 and details of the methodology since 1993!

So where does this leave Treadgold and the CSC? They have published a report, issued press releases and made blog posts that misrepresent the facts, and have shown themselves incapable of conducting good science. They have proven themselves morally and ethically bankrupt, and should — if they had any decency — withdraw and apologise. But I won’t be holding my breath.