NZ temperature record — it’s worse than we thought

Thanks to those who advised me of this amazing email from the Climategate 2 collection, either through comments here or private email. It concerns the pre-1930 cooling of the New Zealand temperature record, and makes food for thought, especially for those supporting NIWA, Salinger and the increasingly shaky AGW story. Although it’s more of a novel, and a bad one at that, with gaping holes in the plot and evidence so carelessly thrown together it fools nobody. Now, as many of us feared was the case, comes evidence that the NZ temperature record has been applied to far more places than where it was observed. We now know it was stretched over far-flung places it was never intended to go. This is the worst result possible.

date: Mon, 7 Sep 2009 00:13:56 +0100 (BST)
from: “Tim Osborn”
subject: New Zealand summer temps

Hi Phil,

just a quick Q before I go to bed!

I’ve just updated the IPCC paleo chapter Southern Hemisphere plot where we
showed, amongst other things, Ed Cook’s New Zealand TRW reconstruction,
with CRUTEM2v Jan-Mar smoothed temperatures.

For my update I’ve used CRUTEM3v, expecting them to be rather similar but
with a few more years on the end.

But the pre-1930 temperatures are now very different, being much cooler
(by > 0.5 degC for a 25-year low-pass mean) in CRUTEM3v than CRUTEM2v.
Previously they had been, on average, near or even above the 1961-1990
mean, now they’re at -0.5 degC.

Is this a result of some homogenization work on New Zealand summer temp
data? Or just some random artefact of minor changes somewhere?



— Dr. Tim Osborn RCUK Academic Fellow Climatic Research Unit School of Environmental Sciences University of East Anglia Norwich NR4 7TJ, UK

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CRU staff noticed that somebody had tampered with New Zealand’s temperature record, by reducing the early 20th-century levels by more than 0.5 deg.

This tampering introduced a major bias into the trend – also more than 0.5 deg.

Presumably, the only person with the authority to make this change would be Phil Jones himself. Yet he was also responsible for CRUTEM2v which was based on Ed Cook’s published reconstruction of NZ temperatures. And for the IPCC graphs based on CRUTEM2.

It must have taken a strong case to change Phil’s mind on something this important. Who made that case? Where is it recorded? Did he respond to Osborn’s email?

Huub Bakker

I had a quick look through the Climategate 2 emails and found this one, 0279, written a few days later. Where did yours come from Richard, Climategate 1? There are obviously several missing in between; maybe in the encrypted annex to Climategate 2? date: Mon, 14 Sep 2009 16:14:30 +0100 (BST) from: subject: Re: new zealand temps: crutem2 to crutem3 to: “Tim Osborn” Tim, Maybe you should see David if he can recall making any changes to land stations over NZ – and if so when? There might have been changes immedaiately after Jones and Moberg (2003) that Harry wasn’t aware of. Another thought is to check whether your programs work with CRUTEM2 as of now. CRUTEM2 data are on the CRU site, go to the temp page and they are near the bottom. Cheers Phil > Phil, I had a look at figure 1 of Brohan et al. showing land station > coverage and coloured dots for new/deleted/edited stations. All in > New Zealand are black, implying no change from CRUTEM2! I’ll check > with programs again in case I screwed up, but fairly confident I > didn’t — so its… Read more »

It comes, according to my impeccable academic source, from Climategate II.

I regret I can scarcely keep up with my inbox at the moment, much less research anything, so I must leave this to others for now.

But I note: “This one would be good enough. I don’t know if it is the right one.”

A cavalier attitude to science, indeed.

Richard C (NZ)

Salinger 1995 has this:-

“Fig. 3. New Zealand temperature response areas and stations used in this study (after Salinger, 1979).”

That’s for the T3 region, so the data up to 1979 would not have changed between 1979 and 1995 presumably.

What date was the CRUTEM2 to CRUTEM3 changeover?

Alexander K

Richard T
When one is searching for pre-determined measurements to support a particular scenario, knowing whether anything is ‘the right one’ is irrelevant.
‘Cavalier’ is too mild a description for this chicanery: ‘totally dishonest’ is nearer the mark for me.


Reading the Climategate emails, I get the impression of a bunch of guys preparing material for a marketing presentation rather than engaging in what we know as science.

Gidday Kiwis – great post.
I reported this in May 2007 – so it took Tim Osborn 2 yrs to wake up.
See my blog post – “Hadley Centre inserts more warming into New Zealand climate history”
Some answers to questions above – the Jones et al CRUT2 ended in 2005 and used pretty much raw NZ data.
The higher warming CRUT3 is a creature of the UK Met Office – Hadley Centre – and has inhaled versions more NIWA friendly. Jones was listed as the last author on that paper Brohan et al 2006.
I wonder who the David is – ref the 14 Sep 2009 email above from Phil Jones – possibly Parker I suppose.

Richard C (NZ)

Hi Warwick, this is illuminating.

I’ve looked at peer-reviewed trend analysis (linear, polynomial, EMD, intrinsic/extrinsic etc) of land-SST HadCRUT3 and pragmatically accepted that dataset because of all the work done on it and because the SST component negates much of the UHI and adjustment problem. Compare HadSST2 and HadCRUT3 side-by-side:-

Basically the same series and the 1940s warming is still intact. Not so in the (I assume) land-only CRUT3. The CRUT3 1940s “adjustment” is highlighted in an ICECAP post by Joseph D’Aleo, ‘NASA Games’:-

The incriminating CRU plot being this one:-

The 1940s anomaly drops about 0.2 C. I’m thinking that the NIWA “adjustments” made it through to the land-only CRUT3 (along with lots of others) but not to the land-ocean HadCRUT3.

BTW, HadSST2 and HadCRUT3 are topical in comments under this post in terms of recent OHC build-up – or not:-

I should have added that CRUT3 is a misleading term IMHO – should have been HadT3 or UKMOT3

Richard C (NZ)

Clive Best on CRUTEM3:- Can empty grid points similarly affect the anomalies? The argument against this, as discussed above, is that we measure just the changes in temperature and these should be independent of any location bias i.e. CO2 concentrations rise the same everywhere ! However it is still possible that the monthly averaging itself introduces biases. To look into this I calculated a new set of monthly normals and then recalculated all the global anomalies. The new monthly normals are calculated by taking the monthly averages of all the stations within the same (lat,lon) grid point. These represent the local means of monthly temperatures over the full period, and each station then contributes to its near neighbours. The anomalies are area-weighted and averaged in the same way as before. The new results are shown below and compared to the standard CRUTEM3 result. Fig5: Comparison of standard CRUTEM3 anomalies(BLACK) and anomalies calculated using monthly normals averaged per grid point rather than averaged per station (BLUE). The anomalies are significantly warmer for early years (before about 1920), changing the apparent trend. Therefore systematic errors due to the normalisation method for temperature anomalies are… Read more »

I have not yet digested the Clive Best article – however seeing the question “Can empty grid points similarly affect the anomalies?”
I was reminded of my report into bogus warming claims in the “Northern Siberia, Taymir Peninsular Region”.
there I found that empty 5 degree grid cells can certainly be assigned more warming than you would expect from surrounding stations.
Or as I put it then;
[2] Interpolations of data to grid cells devoid of stations ends up with higher warming trends than the parent data ???

At the time I emailed Phil Jones about this – he wriggled out of an explanation by saying there was a new paper coming out which explained all. For the IPCC Glitterati there is always a new paper coming out. Other standard Phil fend-offs were, “just arrived back from somewhere” – and “just rushing off to somewhere”.

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