The Australian Bureau of Meteorology (BoM) and their political echos have been all over the media today with the claim that the years 2000 to 2009 have been the hottest decade in Australia.
Lacking the resources to quickly check the entirety of the BoM claim, I checked Alice Springs data – being at the core of our hot land.
The tenuous BoM claim comes crashing to earth so quickly – in the 1990-1999 decade. The average mean annual temperature in the Alice for the decade 2000 to 2009 is 21.441 degrees C. Then the average for the next decade – 1990 to 1999 is 21.645.
And yes their claim also fails in the 1880’s.
My graphic shows the 21.645 peak at 1999 (= ten year average for years 1990-1999)
Poor old BoM – a gaping hole shot so quickly in their beautiful construction – I wonder how many tax payers hard earned dollars the BoM wastes on these sorts of politically correct but unproductive exercises – at a time they find it too hard to gather complete rainfall data at many sites.
I will run more checks as global datasets are updated to the end of 2009.
A few words about what I think would be balanced statements to make about 2000-2009 climate in Australia. Of course it has been a hot decade but I doubt it is significantly warmer in a statistical sense to earlier times, including the late 19th Century – which the BoM cunningly try to exclude. IMHO 2000-2009 could be said to be “well within the normal range for Australian decadal natural temperature variations”.
Get monthly mean max and mean min data from this link
Some headlines
SMH – “Hottest Decade on record”, BOM – “Second Warmest Year .. lingering rainfall deficiencies.. Warmest decade on record”.
Garrett – “Australia is one of the hottest and driest inhabited places on earth and blah, blah, blah”.
Compare Garrett with what BOM said “Australia as a whole has been getting warmer for about 50-60 years and it’s actually been tending to get wetter said David Jones, BOM Climatologist.”
My headlines “Second wettest decade on record, daily rainfall totals exceeded previous records, record rainfalls”.
My pick with BOM is in using 1960-1990 as their benchmark for comparisons.
This just happens to include one of the coldest decades 1970-1979. This was the decade that gave rise to all that talk of the coming ice-age!
My other pick is with David Jones commenting on the 3 record breaking heatwaves in 2009.
“To get one of them in a year would have been unusual. To get three is just really quite remarkable,” said Jones.
This is like saying that getting a repeat of Lotto numbers is remarkable. No, they are just as likely as any other combination of numbers!
I have found the same thing with stations like Casino, Murrurundi, Nobby’s Head (Newcastle), Gunnedah and others. I have found that in many instances (especially rural stations) that earlier data (prior to 1950) has been ‘dumbed down’ by up to 0.5C and by up to 0.3C prior to 1980. More recent temps have been unaltered. I’m sure that Geoff S and yourself are aware of these ”manipulations’.
I examined many stations with long-term records (mainly Qld, NSW, Vic) and found that 1914 averaged higher max temps than 2008 – yet 2008 is shown to be warmer than 1914 in official graphs (due no doubt to the ‘homogenization’ of earlier records).
They also say that the rainfall is below average for 2009. Qld, Tasmania and Northern NSW have been well above average with Victoria and SA having better falls than 2008. Central Aust has admittedly been very dry but with water in Lake Eyre, one would not expect rainfall for 2009 to be below average.
The BOM’s historical climate service pages are down at the moment (hopefully for the updating of data) in order to check the raw figures.
There is no doubt pressure is being applied to the Opposition to pass an ETS. The Bureau’s own 2009 summary has been taken to a new level (compare 2009 to prior yearly summaries) so a political agenda will dominate the climate change debate to even a greater degree. I doubt if our voices will be heard above the noise.
The headlines showing “the Hottest decade” are from the data provided by the BoM which most peple would imagine would be an impartial organisation, but if you read their website, it clearly states that the figures are provided by the University of East Anglia, which at best is considered to be suspect. One would have to ask why does Australia not work out our own figures, but instead sends them off to a secretive organisation that will not reveal why their published figures do not seem to match the temperature changes (or lack of) that most people find when they look at real life temperature readings.
I was confident you’d be on to this quickly, Warwick. From WW1 to WW2 this country sizzled. As I’ve said before, my part of Oz set every monthly maximum record, bar one, between 1910 and 1920. The exception was August, 1946.
The strategy seems to be to wait for some hot weather and announce some kind of terrifying data. The mild winter past and the spring/summer heat in southern Oz have been perfect for their “trick”, to borrow an East Anglian expression. As for the fierce winters of ’07 and ’08, and the fact that NSW has just broken its drought in a supposed El Nino…the “trick” is not to talk about it!
I found old data and charts at BoM, they showed NO rises in temps and in fact showed the 30’s to be as high if not higher, sadly I didn’t screen save and a week later they had vanished! link now goes to a completely different page, how convenient?
I saved a lot of the historical pages afterwards though:-) so it will be ver interesting to look at what they Replace/omit, won’t it!
The Australian Bureau of Meteorology points out in its announcement re 2009 being the second hottest year ever that “An unusual winter-time heatwave occurred during August over large parts of inland Australia and resulted in Australia’s warmest August on record.”
See … www.bom.gov.au/announcements/media_releases/climate/change/20100105.shtml
August was also the month that the BoM web data suffered a “bug” that needed an upward correction of almost .5 degrees C for all its land station temperatures in Western Australia and, as far as I can ascertain, the other half of the country as well. Below is a copy of a message I posted on WUWT about a month ago:
Last week while updating my website (www.waclimate.net) with temperatures for November, I noticed something peculiar about August 2009 on the BoM website. The mean min and max temps had all gone up by about half a degree. Below are the min and max temps for the 32 WA locations I monitor, with the BoM website data at the top as recorded from Sep 1 to Nov 17, and below them the new figures since then …
August 2009
Albany
9 16.2
9.4 16.6
Balladonia
5 20.7
5.5 21.1
Bridgetown
5.7 15.7
6.2 16.1
Broome
14.6 29.2
15.1 29.7
Bunbury
8.2 16.7
8.7 17.2
Busselton
8.7 17
9.2 17.4
Cape Leeuwin
11.8 16.2
12.2 16.6
Cape Naturaliste
10.5 16.7
11 17.1
Carnarvon
11.4 23.2
11.8 23.6
Derby
15 32.7
15.6 33.2
Donnybrook
6.7 17.2
7.2 17.6
Esperance
8.3 17.7
8.8 18.1
Eucla
7.9 21.5
8.4 21.9
Eyre
4.3 21.6
4.5 22
Geraldton
9.5 20
10 20.5
Halls Creek
16.1 32.6
16.6 33
Kalgoorlie
6.8 20.3
7.2 20.7
Katanning
6.1 14.7
6.5 15.1
Kellerberrin
5.3 18.6
5.6 18.9
Laverton
7.5 22.4
7.9 22.9
Marble Bar
13.8 31.1
14.3 31.5
Merredin
6.1 17.7
6.5 18.1
Mt Barker
6.8 15.6
7 15.8
Northam
6.2 18.4
6.6 18.7
Onslow
13.8 27.7
14.3 28.1
Perth
8.8 18.5
9.3 18.9
Rottnest Island
12.4 17.3
12.9 17.7
Southern Cross
4.6 18.1
5 18.6
Wandering
5.3 16.1
5.6 16.6
Wiluna
7.5 24.8
7.7 25.2
Wyndham
18.3 34
18.8 34.4
York
5.6 17.9
5.9 18.3
I’ve questioned the BoM on what happened and received this reply …
“Thanks for pointing this problem out to us. Yes, there was a bug in the Daily Weather Observations (DWO) on the web, when the updated version replaced the old one around mid November. The program rounded temperatures to the nearest degree, resulting in mean maximum/minimum temperature being higher. The bug has been fixed since and the means for August 2009 on the web are corrected.”
I’m still scratching my head because the bug only affected August, not any other month including September. Also, there’s no change to the August data on the BoM website and they’re still the higher temps. So if anybody has been monitoring any WA locations at all via the BoM website, be aware that your August temperature data may be wrong, depending upon whether you recorded it before or since Nov 17, and it’s not yet known what’s right and what’s wrong.
BoM data now shows that across Australia the August 2009 mean was 2.47 degrees C above the 1961-1990 average they use as a baseline, the previous high being in 1998 when August was 1.49 degrees C above the average. July 2009 was 0.78 degrees C above the average (9th warmest since 1960) and September 2009 was 1.22 degrees above average (11th warmest since 1960), so August was outstanding.
Based on these homogenised figures from BoM, August was the hottest it’s been since 1910 across Australia, but it should be noted that the August data originally had a bug that had to be corrected with an increase of about .5 degrees C – presumably with a small influence on the national annual average as well.
Incidentally, since the bug was fixed in mid-November, average maxima at all Western Australia locations have been very high.
Your observations are spot-on Warwick, and your shot at David Jones, a supposedly senior scientist, is also well-based. He is a well-known warming alarmist and will brook no opposition nor will he concede any good points made by anyone outside his green clique. BoM leadership at the moment is a complete shambles and an expensive disgrace.
I have had a look at the small town of Gayndah in Qld which is a shire centre. The Post Office temperature records goes back to 1893 and the rainfall to 1870. In 2003 records started at the airport about 2km away. The PO records ceased in mid 2009. So there is an overlap. The min and max at the airport are both 0.2C lower than at the PO. Looking at the satellite the PO is in the main street fronted by a divided four lane bitumen street and next to a health centre which would have air conditioning. The records show a remarkable jump in both max and min temperatures around 1975. I estimate the jump up around 0.5C. The airport has a bitumen runway and a bitumen tarmac at the terminal building. I have been gliding at Gympie which has a similar bitumen runway and experienced the thermals over the airport and the nearby highway.
The records at Gayndah show the hottest year as 1897. Over the more than hundred year record the increase has been 0.5C. If one takes away the ca1975 jump (probably due to heat island effect) then the increase is zero.
I found an interesting thing while checking Lismore data (Centre St, Site No: 058037). The raw data for 1915 shows a yearly max temp of 27.4C. But when you pull up the graph for Annual Maximum Temperature the 1915 temp becomes 26.7C, a drop of 0.7C. This seems to happen with the higher temps prior to 1940. More recent temps are shown as per the raw data.
This has the effect of making the temperature trend appear as a constant warming one when in fact it should be more of a flattened U shape if you use the raw data only. This appears to be the case in many individual NZ, Russia and Scandinavian sites as well.
GIS also homogenize the raw data by ‘dumbing down’ earlier records but not more recent temps.
Go figure!
I noted on a post at WUWT about urban warm bias in GHCN data that the temperature increasing trend began in 1975 when the number of stations around the world started to be reduced. However, I wonder if there was in addition some fiddling with the in coming data at the source. As show with the Darwin record has BOM, for example, put in a bias factor which caused an increase rather than a reduction to match older records and rural surrounding data?
Could 1975 coincide with the introduction of electronic recording where it is easy to build in a bias factor?
I have recently purchased an electronic rain gauge. I found that it was giving a reading well below the old measuring gauge. I calibrated the old gauge by weighing water on a precision laboratory balance and found that all gauge levels upto 100mm were accurate to =/- 0.5mm. I found that the electronic one was low by a factor of 1.25 at 100mm rain (weighed water quantity put through over one hour and counting the wireless pulses). The reading can be out by a factor to 2 at low rainfall (less than 1.5mm). Unfortunately the cheap instrument does not allow me to make an electronic correction so they will check them in parallel for a few months and then make manual corrections to the recorded data.
Great work Warwick! Its getting to the point where you cant trust anything out of the BOM anymore