ON Friday 29 October 2010, The Cairns Post reported on the recently released Climate Change Report with respect to impacts on the Far North Queensland region. One of the statements contained in the article was:
“The number of days over 35C in Cairns is expected to triple and the Gulf and Cape can expect longer drier spells interrupted by more intense rainfall.”
If we just focus on the number of days over 35C statement, then how is this qualified? The words “expected to triple” are with respect to what baseline? How is this expectation derived, from historical data or models? The historical data can easily be checked by downloading the records for Cairns from the BOM website (http://www.bom.gov.au).
The results are shown in Figure 1, Temperatures for Cairns above 35°C from 1943 to present.
The long term average number of days above 35°C is 3 per year. There have been four years in the past (1956, 1971, 1988 and 1992) when the number of days has trebled or more above the long term yearly average. It can therefore be expected that this may occur again in the future as part of the natural variation; in fact looking at the frequency of these events, Cairns is overdue for another one of these above average years. The interesting question is should this not occur for say the next 10 years, does this refute the expectation being reported in this newspaper article? Does this graph in fact support the concept that there has been a lack of evidence for warming in the Cairns region since 1996 and is the natural climate cycle in this region still operating within an historical range? Is there justification for an alternative view that the climate in Cairns may be moving into a cooling phase? As usual only time will tell.
Returning to the use of the unqualified word such as “expected”, what does this mean? There is no probability assigned to this descriptor. Yet based on the historical data a probability can be assigned to the hypothesis of a trebling of the number of days with temperatures above 35°C from the long term average for Cairns. According to the records this value is 0.06 (or a 6% chance). Ironically there is twice as much chance (14.7%) that there will be no days above 35°C.
The warmest period for Cairns shown in Figure 1 is from 1988 to 1995, and currently 2010 has reached the long term average of 3 days above 35°C. With the current La Nina pattern in effect it will be interesting to see what maximum temperatures are recorded for November and December of 2010. At this stage it is clear that the 2000’s have not shown any unprecedented warming in the Cairns region based on this maximum temperature parameter.
Dr B Basil Beamish
Senior Lecturer in Mining Engineering, School of Mechanical and Mining Engineering, The University of Queensland, Brisbane Qld 4072
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
‘Cairns is overdue for another one of these above average years.’
Probably yes, 1956, 1971 and 1988 were all La Nina years, but not 1992 according to BOM.
Interesting post, particularly when you look at the 1990,s compared to the 2000’s, also considering we’re comparing a warm phase PDO to the start of a cool phase PDO, during those periods.
The big C/Phase PDO from 1945 to 1975 lasted about 30 years and more la ninas and stronger la ninas occured then and to the contrary the 1976 to 1998 W/Phase PDO seemed to favour more and stronger el ninos.
The really big flood years of the MDB occured during the cool phase PDO as well and it will be interesting to see whether we may be seeing a return to more average rainfall years in MDB and perhaps more average negative IOD phase as well during the coming years.
Overall of course Australia from 1955 to 2009 is a much wetter country and so is the MDB.
You need only subtract the last nine years of rainfall from the MDB record to see that up to 2001 it had much higher rainfall than the first 55 years of the 20th century.
Check this out for yourself by trying a 5 and say 15 year average line through the graph, also the trend line ( + 3.24mm/ decade ) or just adding up the rainfall totals for the two periods.
Well I guess instead of speculating we could “read the actual report”
“Figure 19 shows the average number of hot days
(days with a maximum temperature greater than
35 °C) projected to 2050 for a selection of
Queensland locations. The current number of hot
days is calculated using a base period of 1971–
2000 and the values in brackets are an indication
of the range of projections from the different
climate models (10th and 90th percentiles).”
So it’s at 2050 – so temperatures this year or next of little relevance.
The base period is defined.
There are 3 emission scenarios – triple is for the highest.
we are to expect 15 cyclones this year, according to BoM.
The 1949-50 La Nina looks familiar, wonder if the Indian Ocean was warm?
http://www.bom.gov.au/climate/enso/d6a1950.shtml
luke
“So it’s at 2050”
That’s the way!
This is where T Flannery has gone wrong, predicted events in the foreseeable future, silly man!
While watching Stephen Fry in NZ http://www.abc.net.au/tv/programs/lastchancetosee.htm I had enough time to put the BBB view in perspective.
What we have is a piddling comment by industry hacks on the QLD gov and it’s agencies’ attempt to qualify “climate change” as it affects populations and practices without regard to broad studies that must go before such a report.
It did not take long to compare this project –
http://www.climatechange.qld.gov.au/whatsbeingdone/climatechangestrategy/towardagreenerqueensland/energy.html
and links to Carter, Idso and other foe running with SPPI etc doctrine that attacks our CO2 link
So Johnathan – let me get this right – and correct me if I’m wrong – you don’t think climate change should be about the future. In fact – that’s brilliant – let’s make it about pink elephants instead.
luke
Don’t verbal me please!
I said no such thing!
Merely pointed out that a prediction in 40, 50 or a 100 years time is a safe bet whatever happens.
Anything based on computer modeling better be forecast so far in the future that nobody will remember the soothsayers.
By anything I meant relating to climate prediction.
Modeling works extremely well when all the factors are known!
Luke,
Thanks for the clarification of the Climate Report baseline of 1971-2000. This period also matches the long term average of 3 as per my analysis. It therefore does not alter my findings, nor the probability of events if you use all the historical data for the site.
You also refer to the fact that the scenario reported in The Cairns Post was the worse case scenario, but this was not made clear in their article, and that was one of the reasons for my post on this matter. Too often it is the worse case scenario that is reported with no clarification of the probability of it happening. The general public are therefore bombarded with gloom and doom, which is neither good reporting nor good for the future of science in this matter. Also, please note that the BOM site filter for temperatures greater than 35C is not working correctly as it also highlights temperatures equal to 35C, which makes me wonder if their algorithm for calculations is also affected by this incorrect use of the cut-off value.
cheers, Basil
Yet another interesting finding in the field of climatology!
CAGWers are so good at adhering to the ‘consensus’ view that a robot can successfully emulate them!
Alarmist spammer unleashes Twitterbot to stifle climate debate
Prison Planet
November 5, 2010
http://www.prisonplanet.com/alarmist-spammer-unleashes-twitterbot-to-stifle-climate-debate.html
Warwick Hughes is in hot pursuit of answers. Are Wang’s temps a fraud?
http://www.warwickhughes.com/blog/?p=204
Sorry about the above post, out of date and off topic, but while we are talking about the extra heat in Cairns, Ken Stewart would like to say a few words on the UHI.
http://kenskingdom.wordpress.com/2010/04/19/climate-confusion-in-cairns/
Following earlier advice , a glance at the web site climatechangeinaustralia.com.au, reveals the CSIRO report, with a link to projections to selected Australian cities.
The apendix (B) is prefaced by “In this climate change projections based on the probabilistic method are given for a set of 14 selected sites. Results are
indicative in that they are based on the results of global climate models for the locations and do not take into account local topographical effects (see sections 5.1.4 and 5.2.4). Changes (relative to 1990) are shown, except for days over 35ºC.
for Cairns Table B4 shows current days over 35C as 3.8 eg the average metioned in the post, a tripling of this is approx 12, that correlates to the 2070 B1 50p scenario (B1 is a lower emission scenario). the table also shows two A1 story lines AIB in 2030 at 6.6 days (50p) and the agressive fossil fuel use tale of A1F1, with 50p results of 44.4 days.
For Hobart days over 35C will probably increase from 1.4 to 1.8 under the B1 scenario providing we do not have a global financial crisis to destroy the story line. Oh, to enjoy 4 days of hot weather( a tripling like in Cairns), what a pity Tasmania has already reduced its 1990 emissions by over 20%, even if the A1F1 story book was opened, Hobart would still be less than 4 hot days in the worst case guess.
Basil’s comment about “doom and gloom” is spot on; even if you overlook the dodgy levels and standards of certainty on which doom and gloom is based the AGW bandwagon also ignores, if AGW were true, any positives from its effect. In fact AGW states that every effect of AGW is destructive to both nature and humankind; I challenge luke or any other AGW fillibuster to point to one example in the official AGW literature where a benefit freom AGW is even considered.
As cooling gathers speed the Denialti won’t make the same mistakes as the warmists – its not all gloom and doom. The Russians think we are facing 20 years of cooling and then warm again until the end of the century, after that we slip into a mini ice age. Well past our ‘used by date’.
In the meantime we can look forward to the beginning of global warming around 2050.
This crap would have been produced by the same DERM doofie (the plural of doofus) who told me at the last SLATS meeting I attended a few years ago that we wouldn’t see any cyclones down SEQ way for at least 30 years. Funny how a 30 year estimate can translate into a 3 year reality, don’t you think? But even funnier how they all claimed their modelling was dead right back then and is still dead right now with completely contradictory results. Just another day in the brave new green bimbotopia. Less is more at the Ministry of Climate Truth.
Cinders,
It would seem that the report contains a higher average either due to the BOM algorithm that uses >= instead of > and therefore counts 35.0 values in their analysis. Go to the BOM site and you can check this for yourself. I also prefer to use the raw data and there may be a few upward adjusted values as we all know from the work of Ken Stewart and others that would raise the average in the report.
I have applied the same analysis to Hobart, which I also keep an eye on, having spent my undergraduate years there. The long term average from 1943 to present runs at 1.1 days per year above 35C, and there have been 9 occasions in that time when this value has been 3 and on 1 occasion there was 4 (2003). Therefore the probability of trebling the long term average is about 15%. The probability of another 4 days above 35C occuring in a particular year is 1.5%, so don’t hold your breath waiting for that joyous day.
I think these modeled scenarios should be matched against actual over the next 10 years to prove their validity. A running tally should be kept to compare against the simple probability analysis from historical data. Such a comparison should confirm whether natural variation is at play or not.
Cheers, Basil
Cohenite – too easy. Discussion the other day about seagrass doing better. And have I not always said God loves a US WASP wheat farmer. So right side of ENSO – more temperature, more CO2, better rain. They should do better. AGW will have winners and losers on rainfall distribution.
Framing AGW as totally catastrophic is totally disingenuous. As is pretending humanity does not already have problems with climate.
For heavens sake read something other than blogs.
You guys have now sunk so far into the depths of sceptic nihilism that you can’t see anything.