The big warm: NZ heading for warmest-ever winter

If you think it’s been a warm winter in New Zealand, you’re right. NZ is rapidly approaching the end of a record-breaking winter — the warmest for at least 150 years1. Calculations by Auckland climate scientist Jim Salinger show that NZ’s average temperature for June/July/August is running at 9.5ºC, a remarkable 1.2 deg C above the 1971-2000 average, and comfortably ahead of 1998’s old record of 9.3ºC. Commenting on the numbers, Salinger notes the absence of cold snaps in recent months:

The door to cold spells from the Southern Oceans — apart from a brief surge in June — has been well and truly closed this winter. September-like temperatures have been occurring throughout August, giving the country its warmest winter and August ever.

The long term warming signal is clear, he says:

The clearest climate warming signal is seen in winter, where temperatures are now 1.1 deg C warmer than they were around 1870. The warming trends have been very consistent, especially since the 1950s, when frosts days have decreased dramatically across the country.

I can certainly vouch for the absence of frost. At Limestone Hills, we recorded 19 frost days in 2011 and 23 in 20122, but only 6 so far this year. Evidence of winter warmth can be seen in gardens around the country. The asparagus spear pictured above first poked its head out of our soil two weeks ago, and is now being joined by half a dozen more — at least a month earlier than normal for North Canterbury.

To unpick just why this winter’s been so warm, I asked VUW climate scientist Jim Renwick to look back at the atmospheric circulation set-up in the New Zealand region. Here’s his (lightly edited) analysis:

Continue reading “The big warm: NZ heading for warmest-ever winter”

  1. Reliable temperature records in NZ date back to the 1860s. []
  2. For the full year. Frost days are any day where the temp falls below zero, and are unusual (1 – 2 a year) after August. []

Signs of things to come: Salinger on Australian heatwaves

Climate change is happening now and Australia is in the firing line says Jim Salinger in this guest post. This article first appeared in the Dominion Post.

As I watch from my summer subtropical perch in Brisbane, Queensland, the somewhat unprecedented rains that deluged parts of Australia during the summer of 2010/11 have been replaced by sizzling heat waves this summer. These raise some pertinent lessons on climate and risk management for New Zealand. Firstly let’s look at some figures and ask the question of what are the climate mechanisms behind the heat waves.

For December 2011 the Bureau of Meteorology figures show that the highest temperatures of the year occurred in the third Australian heat wave of the year. This affected the Pilbara region in the north west of Western Australia. Multiple sites broke the previous Western Australian December record of 48.8ºC on December 26, 1986 with Roebourne recording 49.4ºC on December 21, Onslow Airport recording 49.2ºC on the 22nd and Learmonth 48.9ºC on the 23rd. Roebourne’s 49.4ºC was the highest temperature recorded in Australia since 1998.

This month incessant heat has struck the interior with daytime highs soaring to the mid forties. As I pen this there are a few more days of this heat wave left with temperatures averaging between 35ºC and 40ºC in central Australia. Places have been recording daily lows of 30ºC and daily highs of close to 45ºC. Mean temperatures have been running over 6ºC above average.

Continue reading “Signs of things to come: Salinger on Australian heatwaves”

Things to do in Wellington and Dargaville

Late notice, for which I apologise, but climate scientist Kevin Trenberth is giving a public lecture in Wellington on Friday (July 15th) on The Russian heatwave and other recent climate extremes. Trenberth’s talk is being organised by the NZ Climate Change Research Institute and will be at the Old Government Buildings Lecture Theatre 2, from 12:30 – 1:30pm. If you can’t make it, you can get a good idea of what he will discuss from this guest article by KT posted at Skeptical Science this week. Well worth a read. Trenberth is also holding a media briefing for the Science Media Centre tomorrow afternoon, which I hope to report on in due course.

Also this week, the Saunders, Oram and Salinger road show has added an extra gig into their Northland tour — in Dargaville tomorrow at 1-30 pm at the Kaipara District Council, 42 Hokianga Road, Dargaville. Contact Chris Donahoe for more information. Jim S also asks me to note that the title of the urban talks ( in Timaru, Auckland and Dunedin) has changed to Preparing for White Swans: Climate change and opportunities for the economy. Full tour details here (pdf).

The CCRI has just released the July edition of their What’s Hot newsletter, full of recent climate related news, linked to the original articles. It’s a good digest of recent news, worth the download.

Hansen in NZ: first reports

James Hansen’s tour of New Zealand is off to a flying start, with an appearance on TVNZ’s Close Up, coverage in the Herald (they got his age wrong) and an interview with the Dominion Post‘s Kiran Chug, followed by a business lunch (or a lunch with business) and an evening talk to a packed room at Auckland University. Jim Salinger reports:

Jim Hansen’s lecture last night was great. The lecture room held 250, and there were 350 stuffed in sitting on the floor and standing room only, with an overflow room full and buzzing.

The talk was recorded, luckily, and can be seen here. Blogger No Right Turn was at today’s Palmerston North session and tweeted: It was a good talk. The thrust: “think of the grandchildren”. No surprises there. Hansen will be interviewed on Kim Hill’s show on Radio NZ National on Saturday morning at 8-15am, and although my sources suggest Kim may want to push a sceptical line, it should be well worth a listen. For a little amusement, Facebook users might want to check out the tour Facebook page, where a couple of NZ’s more incorrigible denialists — Steve Wrathall and Andy Scrace — have taken it upon themselves to post stupid comments. No surprises there, either. Meanwhile, plans are afoot for GR and The Climate Show to interview Hansen next week in Christchurch. Watch (and indeed listen) to this space…

[Update 14/5: Full report on Palmerston North talk at No Right Turn here.]

Fools gold: cranks can’t count

I don’t know whether to laugh or cry. 14 months on from the start of the Treadgold/Climate “Science” Coalition/ACT campaign to cast doubt on the long term New Zealand temperature record, after parliamentary questions, much mud slinging at Jim Salinger and NIWA, legal action, and the expensive and time-wasting reconstruction of a temperature series that’s pretty much identical to the original, diligent digging by Open Parachute/Sciblogs blogger Ken Perrott has revealed a stunning level of statistical incompetence in the “paper” that started it all. Written and published by Richard Treadgold of the Climate Conversation Group, that “paper” contained a graph purporting to show a long term NZ temperature series constructed without adjustments for station moves.

A day or two ago, Treadgold posted a link to the underlying data at his blog, and Perrott — who has been requesting this information for most of the last year — was quick to download it and take a peek “under the hood” of Treadgold’s graph. And what he found was truly remarkable. Treadgold makes no allowances for missing data, makes no attempt to create a valid composite series, simply averages the numbers and plots them on a graph. There are a lot of gaps in the data — especially in the early years — so the “NZ” temperature is in some years just Dunedin, or Dunedin plus Wellington, or Wellington plus Auckland, and so on. Treadgold’s incredible statistical naivete allows him to not just compare apples to oranges, but to feijoas and konini berries as well. The result, of course, is a dog’s breakfast. To make matters worse, he then computed a trend on the data, and announced:

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.

A whole political campaign has been constructed on the back of this statistical idiocy. Variations of Treadgold’s claim have been used in questions in Parliament. Valuable scientists’ time and tax payer money has been wasted pursuing his folly. The Climate “Science” Coalition are still desperately trying to keep the issue alive, hoping that if they can create enough smoke everyone will assume there’s a fire somewhere. Unfortunately for Barry Brill and his colleagues, Treadgold’s statistical incompetence undercuts their whole campaign. Do they really think the NZ public and politicians will take the word of a bunch that sling mud and smear scientists, when they are incapable of doing their own simple sums?

Congratulations to Ken for unmasking this fraud. I eagerly await the fulsome apology Treadgold owes to Jim Salinger, NIWA and the public of New Zealand. Perhaps the NZ C”S”C might offer to repay some of the tax payer funds wasted on this affair. But I won’t be holding my breath…

Meanwhile, I think it’s worth repeating the conclusion to my first post on this affair:

None of these cranks should be accorded any respect in future. By their words shall we know them, and their words show them to be ignorant, bullying fools. De Freitas [science advisor to the CSC] should withdraw and apologise, or resign from his post at Auckland University, and if Treadgold, Dunleavy, McShane, Leyland,or any other member of the NZ CSC want to partake in public debate on the subject of climate science, they should expect derision to be heaped on them and their views.

 

[Update 10/2: Prompted by Manfred’s comment below, I checked back over the original 7SS data and Treadgold’s spreadsheet — as well as with one or two people who might be expected to know ;-) — and it appears that taking a simple average of the annual anomalies in years where some stations reported no data was NIWA’s practise for the original 7 station series. It’s not ideal, particularly in the very early years when there are large gaps in the data, but it’s how it was done. Treadgold was therefore following established practise, in that one respect. I therefore apologise to Richard for echoing that specific allegation without first checking the data. However, this does not get him off the hook for the rest of his “analysis”, nor prompt me to change my overall conclusions. I accused him of “statistical idiocy” and that charge stands — not least because he derives his anomalies by taking unadjusted or raw station data and relating it to a 1971-2000 baseline derived from different stations at different locations using different measurement equipment, and then pretends that he’s made the warming disappear. Tell that to the glaciers…]

[Stone Roses]