In July last year the NZ Climate Science Coalition published an independent analysis of NIWA’s reconstruction of our national temperature record (NZTR) entitled New Zealand – Unaffected by Global Warming.
It’s the only independent analysis carried out on the reconstruction (nobody else has bothered). As far as I know, nobody much has even read the report. So we need to tease out some of the details and start talking about them. They’re a bit startling, considering the diet of alarm we’ve been getting from the news media for the last twenty years.
What would Kiwis do if they knew the facts of the country’s temperature record? Would they demand the government ditch the ETS because there’s no reason for it? Would they march on Parliament?
Because one of the insights from our expert analysis is that there’s been neither unprecedented warming nor strong recent warming in New Zealand, despite claims of both from the alarmists. NIWA certainly supports the theories and policy recommendations of the IPCC, and so it seems to support the idea that we’ve experienced strong warming but, on its web site, says only: “NZ has warmed during the past century“, which is very mild, considering the Royal Society want us to allow for up to half a metre or more (as I recall) of sea level rise by 2100.
But the details are revealing. Our analysis of NIWA’s published data confirms that warming has occurred. But there was no real warming after about 1950. Table 5 on page 19 clearly shows this.
Our report says:
NIWA has relied upon 2000-10 being the warmest decade on record. But climate change concerns relate to temperature changes (i.e., warming), not to absolute temperature levels (i.e., warmth).
Table 5 shows New Zealand’s historical average temperatures since the instrumental record began, divided by decade. The first group is coloured according to mean warmth, with the warmest in red and the coolest in blue. The second group is coloured according to warming trend.
Note that there has been no really significant trend since the 1950s, and that there has been a cooling trend since the turn of the century.
This analysis should come as no surprise, considering David Wratt has been at pains to assure us that New Zealand’s exposure to global warming will be moderated by the dirty great ocean we live in. But still, it gives a totally different picture of the country’s climate from the alarming one generally trotted out by the likes of Salinger, Renwick and the Royal Society, not to mention our Minister of Climate Change, Nick Smith.
But then, the Coalition did examine NIWA’s data—maybe NIWA hasn’t.
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Isn’t it conventional to look at climate trends over periods of 30 years? Does this make any difference to your analysis?
You’re right. But we were looking at the decadal trends, so that’s what we reported. It’s instructive, I think, to learn that the warming of the last 100 years was not constant, like the rise in CO2 concentrations has been constant, nor was there any significant warming since 1950, a period of over 60 years.
As you say, the 30 year period is “conventional”, but it appears to be arbitrary, and to confuse mere mortals, “climatologists” keep advancing it as each decade’s information is complete. A paper written in the last year may well portray different “anomalies” to one written, say, a decade ago because the comparison period has shifted. This highlights a problem of determining trends. The choice of start and end point can have a significant effect on the trend calculated — which is the point of calculating the decadal trends as shown in the table.
Past Climate Variations over New Zealand (cited by IPCC AR4 Australia and New Zealand section)
Climate variations over the last 140 years
In the New Zealand region (T3) the magnitude of warming between the decades 1861 – 70 and 1981 – 90 is 1.1°C. Temperatures increased sharply after the 1940s, but annual mean warming has slowed recently.
Decadal Variability
NIWA scientists have recently identified a long-lasting “shift” in New Zealand’s climate that occurred around 1977 (Salinger and Mullan, 1999). The shift was characterised by more persistent westerlies on to central New Zealand since 1977, resulting in the west and south of the South Island being about 10% wetter and 5 % cloudier with more damaging floods. The north and east of the North Island have on average been 10% drier and 5% sunnier, compared to 1951-76 data. This changepoint of 1977 coincided with an eastward movement in the longitude of the South Pacific Convergence Zone, and more frequent El Nino events in the recent record.
This shift is probably due mainly to a Pacific-wide natural fluctuation that in the USA is called the Pacific Decadal Oscillation (PDO, Mantua et al., 1997), which exhibits phase reversals about once every 20-30 years. The influence of the PDO is well-known in the North Pacific, and has recently also been noted in Australian rainfall ( Power et al., 1998), and in the South Pacific Salinger et al., 2001; Folland et al., 2002). Scientists from Pacific Island countries attending a workshop in Auckland in November 2001 put out a press release suggesting the PDO underwent another phase reversal in 1998. Note that in New Zealand, Australia and U.K. this oscillation is referred to as the Interdecadal Pacific Oscillation (IPO).
http://www.niwa.co.nz/our-science/climate/information-and-resources/clivar/pastclimate
NEW ZEALAND CLIMATE: TEMPERATURE AND PRECIPITATION
VARIATIONS AND THEIR LINKS WITH ATMOSPHERIC
CIRCULATION 1930–1994
M.J. SALINGER* and A.B. MULLAN, 1999
7. DISCUSSION:CONCLUSIONS
The climate patterns are described for three periods within the 1930–1994 record, with change-points around 1950 and 1975. In the first period (1930–1950) New Zealand’s climate was cooler, and the prevailing west–southwest circulation was stronger (as noted by Salinger (1979)). By contrast, national average temperatures increased by about 0.58°C in the second period [1950-1976], and there was more airflow from the east and northeast. The last period (1976–1994) was one notable for frequent El Nin˜o events and comparative lack of La Nin˜a episodes. New Zealand-wide temperatures maintained their level of increase from the first period, in spite of more frequent airflow from the southwest
…
The ocean component of this climate pattern is similar to the El Nin˜o–Southern Oscillation (ENSO) variation, except that the amplitude is largest in the North Pacific rather than in the eastern tropical Pacific
…
The climate trends are consistent with changes in atmospheric circulation over New Zealand and in the wider South Pacific region (Salinger et al., 1996). Surface air temperatures have generally increased 0.4–0.8°C over the period 1951–1990, with the most marked increase since 1975 occurring in the southwest Pacific. Longer term temperature records show this temperature increase amounts to 0.8°C since the beginning of the century
http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291097-0088%28199908%2919:10%3C1049::AID-JOC417%3E3.0.CO;2-Z/pdf
Straight from the horses mouth – it’s all in the PDO-ENSO folks (Gareth Renowden please note).
Meanwhile in the NH, Central England Temperatures (CET) are back where they were in 1659.
http://junksciencearchive.com/MSU_Temps/HadCET_an.html
HADCRU4 is coming out and apparently (Bishop Hill and others) shows warming where HADCRU3 showed none or at least less. How does the official New Zealand records compare with historical HADCRU and GISTemp records over time?
I still can’t see how the NZ review produced the exact Salinger-era record from the original station data without knowing how Salinger did it, or doing whatever it was that Salinger did. You investigated after initiating the re-work. How did they get to the end with the same orginal data you have presented, or does their original data not match your original data? And does the New Zealand adjustments keep getting adjusted like the HADCRU and GISTemp data?
Good question, Doug. I’ve not thought of comparing them, but it’s a good idea, even though one series is regional and the other two are global. It would be interesting. When I get a moment I’ll put the graphs together in a post. In the meantime, our report is here showing the NIWA series before and after adjustment on page 5.
NIWA’s report shows clearly how their review produced the same results as Salinger’s. That is, we can see every adjustment they made and the reasons for them. But of course NIWA doesn’t say why they match Salinger’s, it simply uses the fact that they match to claim that the original series was beyond reproach, apparently not realising that it makes both series look as dodgy as hell.
Our review of NIWA’s reconstruction used their data. Of course, we also prove that NIWA failed to use the approved method they claimed to have used. They made a terrible mistake, and we’ve pointed it out to them. So far, they haven’t even acknowledged us.
No, the NZ data doesn’t get regular adjustments. Just the one hit, improving the warming trend from 0.3°C per century to 1°C per century.
Thanks, Richard. Your comparison will be interesting. The HadCru profile of Iceland has changed so much, it MUST be different from the Iceland profile of their own data. In fact, the majority of local HadCru histories must be different from their originating national data by now unless the national data is revised to match the HadCru data. Only two groups (Jones and Hansen) seem to be constantly revising history.
How would it look if on one side of the page you showed (for example) how Estonia sees their history, and on the other, how Jones/Hansen see it? For page after page? Could be awkward.
Where the heating event is, is a question for me. If we were to take the GISTemp fully integrated and averaged data, and dropped out the Arctic portion, for example, what would that do? And so on and so on. The math is simple: a 0.7C rise over the entire world can be generated by a 3.5 C rise over 20% of the globe, or 72* – 90*. Just the Arctic, everything else stays the same. Which is what I have heard claimed about the Arctic. But then I’ve also heard that other parts of the world are warm. Which means that one or the other is wrong.
The lack of global warming to global warming seems weird.
What is climate change?
In New Zealand, average temperatures are projected to increase about 1°C by around 2040
Last updated: November 2010
http://www.climatechange.govt.nz/science/what-is-climate-change.html
1°C by around 2040 = 30 years and 3.33 °C/Century = 0.333 °C/Decade
1929-1938: 9.4 °C/Century, 0.94 °C rise for the decade
1999-2008: -4.1 °C/Century, 0.41 °C fall for the decade
2011-2020: 3.3 °C/Century, 0.33 °C rise for the decade (projected)
Frightening.
I find it embarrassing that our government could publish this as so-called science.
The IPCC graph is clearly wrong on numerous counts apart from being deceptive. And the history of discoveries regarding climate science apparently stopped in 1987.
Doug
See press release by Warwick Hughes in 2006, pointing out that the (homogenised) HadCRUT grids covering New Zealand showed very little warming:
http://www.scoop.co.nz/stories/SC0608/S00030.htm
Warwick has since discovered a Climategate 2 email, suggesting that Salinger persuaded CRU to change its figures to match his 7SS. I think this was about 2007.
I understand GISTemp data shows virtually no warming in our part of the world.
Barry,
Thanks for the connection!
Every time an area shows non-IPCC profiles (especially when, like NZ, the differences are astounding), the rest of the world has to be “warming” even more than the IPCC average for the homogenized profile to be mathematically correct.
There are something like 156 countries providing the Land Station GISTemp record, in a proportionality to their surface area, of course. If you chop the data off one country at a time when the data is so different from the trend, I wonder when you get the IPCC-reductio-ad-absurdum result that shows the area of silly data.
Awesome, I love AGW denialist websites. Thanks for pontificating misleading drivel.
Please keep it up!
Matt, if you’re serious and not merely promoting Menace Records, accept this assignment: within two days, state what is misleading in this post and describe why, citing sources.
Matt might be one of those drone-bot-things. Note he refers to nothing in the article. He could post the same comment at a hundred skeptic blogs, just to fly the flag for The Cause. Don’t expect a reply – he is a fly-by troll.
Well, yes, I get a lot of those, and mostly the anti-spam software reels them in, but this was sufficiently ambiguous I thought I’d keep the door ajar. He’s got two days.
Are NIWA a little reticent this year in reporting 2011’s average temperature?
They made a song and dance of 2010’s 13.1, perhaps 2011 was not running “Hot Hot” (in the words of NIWA’s Georgina Griffiths).
They prolly have too many adjustments to make before it makes the hot-hot category. This could take time, as they are under scrutiny by certain folk, and they need to take care to hide the decline.