Hon Secretary, Terry Dunleavy MBE, 14A Bayview Road, Hauraki, North Shore City 0622

Phone (09) 486 3859 - Mobile 0274 836688 - Email terry.dunleavy@nzclimatescience.org.nz

25 November 2009

There have been strident claims that New Zealand is warming. The Inter-governmental Panel on Climate Change (IPCC), among other organisations and scientists, allege that, along with the rest of the world, we have been heating up for over 100 years.

But now, a simple check of publicly-available information proves these claims wrong. In fact, New Zealand’s temperature has been remarkably stable for a century and a half. So what’s going on?

New Zealand's National Institute of Water & Atmospheric Research (NIWA) is responsible for New Zealand's National Climate Database. This database, available online, holds all New Zealand's climate data, including temperature readings, since the 1850s. Anybody can go and get the data for free. That’s what we did, and we made our own graph.

Before we see that, let’s look at the official temperature record. This is NIWA’s graph of temperatures covering the last 156 years:

This graph is the centrepiece of NIWA’s temperature claims. It contributes to global temperature statistics and the IPCC reports. It is partly why our government is insisting on introducing an ETS scheme and participating in the climate conference in Copenhagen. But it’s an illusion.

To get the original New Zealand temperature readings, you register on NIWA's web site, download what you want and make your own graph. We did that, but the result looked nothing like the official graph. Instead, we were surprised to get this:

Straight away you can see there’s no slope—either up or down. The temperatures are remarkably constant way back to the 1850s. Of course, the temperature still varies from year to year, but the trend stays level—statistically insignificant at 0.06°C per century since 1850.

Putting these two graphs side by side, you can see huge differences. What is going on?

Why does NIWA’s graph show strong warming, but graphing their own raw data looks completely different? Their graph shows warming, but the actual temperature readings show none whatsoever!

Have the readings in the official NIWA graph been adjusted?

It is relatively easy to find out. We compared raw data for each station (from NIWA’s web site) with the adjusted official data, which we obtained from one of Dr Salinger’s colleagues. 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.

What did we find? First, the station histories are unremarkable. There are no reasons for any large corrections. But we were astonished to find that strong adjustments have indeed been made.

About half the adjustments actually created a warming trend where none existed; the other half greatly exaggerated existing warming. All the adjustments increased or even created a warming trend, with only one (Dunedin) going the other way and slightly reducing the original trend.

The shocking truth is that the oldest readings have been cranked way down and later readings artificially lifted to give a false impression of warming, as documented below. There is nothing in the station histories to warrant these adjustments and to date Dr Salinger and NIWA have not revealed why they did this.

One station, Hokitika, had its early temperatures reduced by a huge 1.3°C, creating strong warming from a mild cooling, yet there’s no apparent reason for it.

NIWA claim their official graph reveals a rising trend of 0.92ºC per century, which means (they claim) we warmed more than the rest of the globe, for according to the IPCC, global warming over the 20^th century was only about 0.6°C.

The unexplained changes to the official New Zealand temperature record cast strong doubt on the government’s assertions of urgency regarding so-called "climate change". Using NIWA’s public data, we have shown that global warming has not yet reached New Zealand (and what does that say for global warming?).

At a minimum, the adjustments made to the official NZ temperature record must be made public. NIWA’s predictions regarding climate change, including changes in temperatures, precipitation, winds, storms and sea levels, must be re-examined in the light of the absence of any changes in temperature to date, from any cause.

New Zealand’s contribution to the global statistics is now under a shadow, so there could be regional or even global implications of these disgraceful "adjustments" which should be investigated.

Now we must ask: do we really need an ETS? For, if all that "nasty" carbon dioxide and methane we are "pumping" into the atmosphere has utterly failed to increase our temperature until now, why ever should it do so in the future?

Below are graphs showing both original and adjusted readings for each of the seven weather stations NIWA uses in its official graph. After the adjustments are made, the temperature trend at each station changes significantly. The seven stations Dr Salinger used to create the graph are (with start dates):

• Auckland (1853)
• Masterton (1906)
• Wellington (1862)
• Hokitika (1866)
• Nelson (1862)
• Lincoln (1863)
• Dunedin (1852)

Find the one nearest your place! Are you feeling warmer yet?

Here are all the adjustments, expressed in degrees Celsius per hundred years:

Six of the seven stations have had their past (pre-1950) data heavily adjusted downwards. In all six cases this significantly increased the overall trend. The trend at the remaining station, Dunedin, was decreased, but the reduction was not as great as the increases in the other six.

This graph helps to picture the differences. Note that, after adjustment, every station shows a warming trend, although, originally, three showed cooling and one (Lincoln) showed no trend. In every case, apart from Dunedin, a warming trend was either created or increased. It is highly unlikely this has happened by mere chance, yet to date Dr Salinger and NIWA refuse to reveal why they did it.

The following graphs dramatically show the effect of the adjustments NIWA applied to the raw temperature readings. The important thing to note is the difference in the slopes of the two trend lines, unadjusted (blue) and adjusted (red). When the slope becomes a climb, or gets steeper, from left to right it means they created warming or made it stronger.