Looks like the local climate change deniers/sceptics/contrarians have painted themselves into a corner. Their bluff has been called and any honest person would now acknowledge their error, apologise and move on.
This all started with the local “Climate Science Coalition” and their blog site “Climate Conversation Group” releasing a report, “Are we getting warmer yet?” last year to coincide with all the media hype over “climategate”. This report was shoddy – the author Richard Treadgold first denied any scientific input or review and then claimed he had a team of scientists who “wished to remain anonymous.” One of the Coalition’s members, Vincent Gray, acknowledged reviewing the document but admitted that he had missed the basic error in the report – the claim that no adjustments were required for site and other changes.
The report basically took a figure used by NIWA showing temperature changes in New Zealand based on records from seven different sites. It claimed that the adjustments used in combining the data were unjustfied – even intentionally false. For example the “paper” claimed that scientists “created a warming effect where none existed.” That “the shocking truth is that the oldest readings were cranked way down and later readings artificially lifted to give a false impression of warming.” And “we have discovered that the warming in New Zealand over the past 156 years was indeed man-made, but it had nothing to do with emission of CO2 – it was created by man-made adjustments of the temperature. It’s a disgrace.”
As I said in New Zealand’s denier-gate: “strong claims indeed. And damaging, even slanderous, ones.”
Because of the public interest in climate data, the NIWA Board and the Minister of Research, Science & Technology, Dr Wayne Mapp, asked that a full review of each of the seven sites be undertaken by NIWA.
Now NIWA reports “That review has been completed, independently peer reviewed, and the report released today represents the results of that work.” (see 7 station series review).
You can download the full report. (169 page PDF, 7.6 MB) if you want some weekend reading.
The telling figure from the report is this one:
It’s just what I expected – some differences in details because of subjective elements in determining adjustments but no change in overall pattern or conclusions.
As NIWA says:
“The key result of the re-analysis is that the New Zealand-wide warming trend from the seven-station series is almost the same in the 2010 revised series as in the previous series. That is, the previous NIWA result is robust. In terms of the detail for individual sites, the 100-year trend has increased at some sites, and decreased at others, but it is still within the margin of error, and confirms the temperature rise of about 0.9 degrees over the last 100 years.”
And their comments on the need to adjust the raw data:
“Long time series of climate data often have artificial discontinuities – caused, for example, by station relocations, changes in instrumentation, or changes in observing practice – which can distort, or even hide, the true climatic signal. Therefore, all climatic studies and data sets should be based on homogeneity-adjusted data.
That is what NIWA climatologists have done in the seven station series, and the seven individual station review documents outline the adjustments.
The raw (original) climate station data have not been changed and are freely available on the NIWA climate database, which means that the NIWA seven station series can be easily reproduced.”
NIWA describes how their report was prepared and reviewed:
“The documents were written by highly qualified NIWA scientists, internally reviewed by other similarly qualified NIWA scientists, and the revised documents were then externally reviewed by Australian Bureau of Meteorology scientists. The external review examined the ideas, methods, and conclusions for scientific accuracy, clarity, and logic.
The NIWA authors then addressed the comments made by the reviewers at the Bureau of Meteorology, and the subsequently revised documents have now been published on the NIWA website.”
So come on Richard Treadgold, the “Climate Science Coalition” and the “Climate Conversation Group.” Where is your apology for the slander in your report?
And what about withdrawing that shoddy report (really just a press release) and admitting your “errors?”
Careful what you ask for. Someone might call your bluff and make you live to regret the request.
Thanks to Gareth at Hot Topic (see NIWA’s new NZ temperature series: plus ça change…).