Dr David Jones, the head of climate analysis at the Bureau of Meteorology, recently attributed a decline in Melbourne’s rainfall to global warming. Amongst various comments, he claimed in The Age that the autumn drying trend could be linked to either human-induced climate change through greenhouse gases or changes in the ozone layer over Antarctica.
Ockham’s Razor, the principle proposed by William of Ockham in the fourteenth century: “Pluralitas non est ponenda sine neccesitate”, which translates as “entities should not be multiplied unnecessarily” would require that Dr Jones choose one or the other theory, greenhouse gases or depletion of the ozone layer, as an explanation for the decline in rainfall.
But does either theory really represents much more than speculation?
Indeed lead authors of the Intergovernmental Panel on Climate Change (IPCC) acknowledged just after the release of their last big report that until major oscillations in the Earth System, including El Nino-Southern Oscillation, Pacific Decadal Oscillation, North Atlantic Oscillation and Atlantic Multidecadal Oscillation, are better understood regional climate, and in particular regional rainfall, is a difficult problem.
Furthermore, there are perhaps other simpler explanations for the recent decline in rainfall.
Indeed Dr Jones recently confirmed that his comments in The Age were based on data from just one weather station: a site in Melbourne’s central business district.
This brings us back to Part 1 of this series in which Bill Kininmonth, a meteorologist formerly with the Bureau, made comment that “the rain gauge in Melbourne’s central business district is now sheltered from the rain bearing winds of the southwest”.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
[Ockham’s Razor] “would require that Dr Jones choose one or the other theory, greenhouse gases or depletion of the ozone layer, as an explanation for the decline in rainfall.”
Complex and difficult questions relating to the global climate must always now have simple explanations? It’s either the ozone later or greenhouse gases? Cosmic rays or greenhouse gases? A complex atmospheric phenomena is not permitted to have multiple underlying causes?
How is this substantively different from last week’s inference here that unseasonably cold weather in the northern hemisphere is evidence of global cooling? That’s right – I forgot – Bolt’s Law.
What an utterly stupid unscientific post.
Breathtakingly idiotic.
And – in an amazing piece of spewy hypocrisy you guys are now quoting the IPCC as source. WTF?
David Jones must be a huge threat to the Australian deniers mafia if he gets 6 whole posts.
Indeed it seems after coming up empty on the rainfall analysis, bone dry in fact, you guys have now reached breaking point. Indeed Cohenite went too soon. This would have to be the worst blog post of all time.
Go Jonesy !
Slim how is this drought not natural when we know that much more rainfall fell from the 50’s through to the 70’s ( under the cool phase PDO) than at any time since records have been kept.?
Was this unnatural as well? Flooding on the Murray Darling Basin system was more frequent than any old timers could ever remember, so according to your calculations there must have been some deeper mystery involved?
The answer was the cool phase PDO as far as I’m concerned and if it comes again more frequent and heavier rainfall will result.
“And – in an amazing piece of spewy hypocrisy you guys are now quoting the IPCC as source. WTF?”
Why shouldn’t Jennifer quote them when they admit that these phenomena are poorly understood.
Bit of reality for a change.
You need to do likewise, Luke.
[I even have trouble, myself.]
So, Luke, why do we have a drop in rainfall in the Melbourne CBD? Is it a consequence of El Nino-Southern Oscillation, Pacific Decadal Oscillation, North Atlantic Oscillation ;-), Atlantic Multidecadal Oscillation, carbon dioxide, methane, hole in the ozone layer or a tall building or something else? It would be unscientific to say all of the above?
PS Luke that image/gravatar is disingenuous. I dreamt you had a beard. 😉
Luke,
I would be very cautious about trying to argue for regional climate change as proof or disproof of anything in particular. I would be inclined to think that being forced to point to regional effects in order to ‘prove’ global warming (because few if any global effects are evident), would and probably should be treated rather sceptically. All it takes is another region showing the opposite effect to destroy the argument.
I’ve borrowed this from the comment section of another website to demonstrate how you end up in a circle with example-counter-example type argumentation:
“The widespread 2007 summer floods in England were described as “not linked to climate change”, but as simple “freak weather”, since the models had predicted drier summers. That may have been because the models had earlier been run after a couple of drier summers.
However, the UK Government review Learning lessons from the 2007 floods managed to twist this by saying
3.6 This report concludes that, based on the evidence of rainfall and river levels, statistically the sequence of events during summer 2007 was very unusual. The associated river flooding does not conform to any currently anticipated climate change scenarios which predict drier summers with less frontal rainfall. However, while there is not yet sufficient observational evidence of an increase in the frequency of intense summer storms, these types of storms, which triggered the extreme convective rainfall in 2007, are expected to form part of climate change in the future.
and then talk about “climate change” 140 more times in the rest of the report.”
Of course if we are considering the “Global Climate State” then that would behove us to define it explicitly in order to discern, statistically significant, departures from it.
Though how anyone could possibly come up with a statistic that described one object is possibly a matter for the medical profession.
How perfect do you want the world to be?
No coal?
No nuclear?
Rudd for PM?
Obama for President?
You can’t have all this and warm, sunny Melbourne weather too.
The problem is that Melbourne is supposed to be cold, wet and miserable. The current drought is causing numerous problems, and costing us money, since now we have to have a desalination plant, which is going to add a huge amount to the water bill.
It seems SJT has been in the Melbourne of old
Jen – so previously you wanted Yan Yean as more representative of near Melbourne conditions. Now you don’t eh? Flip flop.
And why have you left out the major contemporary science yet again?
But at least you are now spelling gravatar correctly. 1 point. OK new persona … clear your cache !
Will – sigh ! yes what you say is somewhat true. But if you have an effect predicted by theory, backed up with observations, statistics with explicable and plausible mechanisms and understood holistically by models one might start to take some notice. You’re essentially saying there is absolutely no evidence that would convince you of anything ever. Now that is true denialism.
Alright Luke, so what caused the the much higher rainfall of the 50’s and 70’s, surely humans must have had an input there as well?
Look at the logic of your argument only 30 to 40 forty years ago we had excessive rainfall and yet now we have a long drought which you claim has somehow been caused by AGW.
I’m sure both events are entirely natural in origin one induced by the cool phase PDO and the other by warm phase PDO and accompanying El Ninos( mostly),
Remember overall southern Australia has been drying out for at least 5,000 years so your arguments are entire fantasy.
If you still BELIEVE this drivel explain in plain language how this dryer mechanism really works, I await your theory with interest.
Again Neville – more ongoing stupidity on something we’ve been over 100 times before on this blog but alas you guys (a) don’t read (b) don’t listen (c) avoid whole slabs of research (d) have your mind made up already.
To your initial question – for eastern Australia in general – yes the generally wet 50s and 70s appear to be an interaction of an unpredictable decadal oscillation in the Pacific which reinforces La Nina impact – i.e wetter wets. However does that mean that’s all you ever want to know.
On this denier blog of course it is.
So if you don’t wish to investigate the material that has previously been provided here and David Jones has eluded to in the lead post well stick with your myopic backwoods view of the world and be happy in the knowledge that whatever happens – for you there will ALWAYS be another explanation that definitely would mean no anthropogenic involvement.
You might ponder of course why the non-El Nino, non-La Nina years, the so-called neutral phase years have also not delivered any rain?
Really this whole tawdry business if a bit of a threshold test for the blog of sceptic fair-dinkumness – it’s interesting that all sorts of complex sceptic theories manage to be sourced, understood and tabled, yet much recent Australian research just can’t seem to be located – and if it can – well shucks it’s just too darn hard to understand.
Or alternatively in the not fair dinkum model it’s really being swept under the carpet.
And golly gee – isn’t that strange when the blog prides itself in bringing little known recent work to the fore. But only certain hand selected recent work.
A strange lingering selective amnesia. A wafting mist of obscurantism. Perhaps a bad attack of Socratic Alzheimer’s.
Luke,
“But if you have an effect predicted by theory..”
No, you have a theory trying to explain an effect ex post facto. Your claim is stated back the front.
“backed up with… statistics…”
The statistical support appears weak. It is easy to create convincing “just so” stories and this tends to be the norm in difficult and complex scientific fields. Statistics by itself works for and against AGW theory, but probably more against so far.
“…plausible mechanisms…”
That’s what’s being looked at sceptically. AGW is a reasonable theory, but showing plausible mechanisms is extremely difficult. This doesn’t just go for AGW. Any theory in this field is going to have similar difficulty.
“and understood holistically by models…”
A model is a mathematical embodiment of a theory. Very useful of course, but not final proof of anything by themselves, and so far the IPCC model ensemble has not been predicting anything successfully (yet), which is not much of a defence if you’re invoking them as good evidence.
“You’re essentially saying there is absolutely no evidence that would convince you of anything ever. Now that is true denialism.”
I think this is where a sceptic differs from an alarmist true believer or a denier, in that reasonable evidence will change one’s position. I have no emotional stake in the outcome. Evidence that I would find convincing, assuming it stands up to reasonable criticisms:
1. Evidence of a hotspot
2. Models that can demonstrate that they have at least decadal resolutions in forecasting periods of warming or cooling
3. That models can make reasonably accurate forecasts at least on global scales
4. Paleoclimatelogical data that demonstrates (when statistically averaged) more gradual cooling when CO2 levels in the atmosphere are high
5. Evidence of relatively stable and consistent ocean warming
6. Any other evidence that a plausible case could be made for.
And since I’m writing this off the cuff, I’m sure I’ve forgotten a few other reasonable lines of evidence that could be included. However, even if CO2 cannot be shown to cause significant warming, ocean acidification may still prove to be a major problem for the biosphere. This is a complex issue and there are multiple factors and concerns that must be considered.
Just as I thought no coherent explanation whatsoever, just more blunder and silly extremist, fundamentalism.
My explanation is scientifically historically correct and if we get a decades long C/Phase PDO (at long last) I’m sure much heavier rainfall will result because that’s what usually happens, no new theoretical nonsense required at all.
Spencer has shown also that the W/phase C/phase PDO’s provide almost the full shift in temp over the last 100 years, then add in the LIA recovery (worth at least .5c ) and the increased solar radiation over the last century and the temp increase is easily explained.
So both temp and rainfall easily explained by science but you stake your all on an increase in a minor gas of .01% or one hundredth of one percent of the atmosphere.
As David Evans said about the co called discovery of the hotspot, ” believe that and you’ll believe anything”. AH BELIEFS A WONDERFUL THING.
So Neville – how many times would you like to be told?
You don’t listen and never have. Typical denier.
Just look at the tripe you’re sprouting – a “recovery” from the LIA – what the hell does that mean – the Earth “recovers” from a bad cold? LOL … “recovers …” yech !
The WHOLE point is that the temperature increase cannot be easily explained at all. And gee I wonder why the PDO didn’t do similar things to temperature for the last 400 years. …. oh dear … fizz …..
Just filing this here:
“Winter rainfall across Southern Australia is modified by the position of the stationary longwave trough, also known as the Rossby Wave. When the trough is over Western Australia then local rainfall is enhanced but the downstream ridge is over Eastern Australia, tending to suppress winter rainfall. This was the characteristic situation in the first half of the 20th century. Over the second half of the 20th century there is evidence that the Rossby Waves shifted westward to the Indian Ocean, such that Western Australia became more influenced by the downstream ridge and rain-bearing systems were pushed further southward. At the same time the trough of the Tasman Sea also moved westward and more over Eastern Australia making the east more favourable for rain-bearing weather systems. The Rossby Wave pattern has again shifted eastward – southern Western Australia is again enjoying enhanced rainfall but eastern Australia is missing its winter and spring rain-bearing weather systems. It is difficult to see how CO2 has affected these weather pattern shifts.
William Kininmonth”
Wasn’t it the PDO five minutes ago?
Luke the LIA temp drop according to Wiki and Ipcc was worth at least 1c and even most leftwing idiots understand that it finished around 1850.
So the temp would naturally increase ( duh duh kindy stuff) and so far it’s increased .6c but Spencer has shown the PDO changes mirror temp , then we have the highest levels of radiation for 11,000 years as well. ( 70 of the last 100 years)
So what’s the fuss about, I’ve shown that it’s all natural and easily explained you and the other looneys persist with the AGW nonsense, what a farce.
Anyhow gotta go, please will someone else explain this natural climate to this foolish fundamentalist.
Luke,
One of the problems I see with many ‘denier’ arguments is that they tend to like to simplify things to the point of absurdity.
What’s the accepted argument on the causes of global warming prior to large amounts of CO2 kicking in as an amplifier? Not meant to be a loaded question, just would like to look at the answer(s) to that.
Let me sketch what I think is a reasonable answer:
“From year x to year y solar activity was higher than normal which caused a slight increase in warming. Then solar activity started to drop around year z but temperatures continued to increase, which paralleled the increase in CO2 in the atmosphere. Or the trend increase was unusually high that could no longer be explained by solar activity…”
Of course the above is also a gross simplification. I’m just trying to outline the type of multi faced explanation that would constitute reasonable evidence to an open minded person. As I stated before, arguing for or against local effects ultimately doesn’t get anyone very far. It’s the big picture arguments that will decide the issue.
Either AGW is incoherent or its proponents have not managed to explain it coherently. It’s plausible to me that problems with AGW relate to communication of these concepts to the public and not with the science itself.
Uhhhh, Luke, what causes ice ages again??
What causes the warm periods in between??
Oh yeah. WE DON’T KNOW!!!!
So exactly how can you tell us what the current temps are supposed to be much less rain fall, solar irradiance, or anything else??
HAHAHAHAHAHAHAHAHAHAHAHAHA
In previous parts of this Marohasy v Jones theme I tried to show there were many possible indicators of rainfall decline around Melbourne besides the gauges beside the CBD. One of those was the historic Yan Yean Reservoir at Whittlesea about 40 km north of Port Phillip Bay. Another was the MMBW diversion scheme on the same stream at Lower Plenty just before it’s junction with the muddy Yarra. At the time I was thinking about the one stream that truly represents the greater Melbourne catchment, but there are others such as the Merri Creek which also joins the Yarra River near Collingwood.
From “Our hot, dry future” – David Jones-October 6, 2008 –
“These days, it can be hard to imagine how Melbourne ever earned a reputation as the gloomy, rain-filled capital of the south. But, growing up in the 1970s, my memories are full of muddy ovals, local creeks in flood and catching tadpoles in puddles that lasted for months on end. How things have changed”
This is a local lad recalling his non sciencentific impressions and I claim they are just as valid as the records in this discussion when it comes to recognising the most important clues to our climate change.
When Kodak moved their works from Abotsford to Coburg in the 1960’s I too got a chance to see the Merri Creek in flood. In fact I should have slides of a terrifing event where houses off Merribelle Avenue etc were in danger of being swept away in the enormous gusher that rose way over the wild annaseed infestations and swirled through the bottom fences well back from the roaring torrent out in the middle. This happened several times right under my nose, but I’m guessing it was all in the year of 1964
This creek and its floods has been the subject of many studies over the decades. This old 1950’s flood photo is close the the new Kodak site.
http://www.picturevictoria.vic.gov.au/site/moreland/miscellaneous/5960.html
Another photo from the 1920’s
http://www.picturevictoria.vic.gov.au/site/coburg/chs/16812.html
One thing we can be certain about, the creek’s writen history and floods etc is as well documented as any other Australian ‘series’ on the www.
http://www.wikinorthia.net.au/index.php/Merri_Creek
see also
http://www.mcmc.org.au/content/view/59/118/.
Thanks Gavin for proving our case for a natural climate.
Yes it’s true that during c/phase PDOs and some strong la nina events we have much higher rainfall and sometimes flooding and your point is what exactly?
Neville; let’s quote David again
“It is now 12 years since we experienced a year that was cooler than average for Victoria. Analysis from a recent CSIRO study using observations from the Murray-Darling Basin has shown that stream-flows may decline by 15% for each 1 degree of warming. With a further warming of about 1.5 degrees projected for Victoria by 2050, and further declines in our winter and spring rainfall, we could experience increasingly low stream-flows throughout this century.
Should Victorians view this drought as climate change? This drought is now far beyond our historical experience. It is very difficult to make a case that this is just simply a run of bad luck driven by a natural cycle and that a return to more normal rainfall is inevitable, as some would hope”
Neville: My point is that an astute student of climate change has many records to find in relation to Melbourne’s recent past and it’s my bet major floods along the Merri Creek have diminished somewhat over the past hundred years or so. I can say that knowing this stream has not been diverted into the domestic water supply in the way others nearby have.
Imo your “smart” rear end comment adds nothing to this debate since it’s unrelated to either rainfall data or streamflow records for the area in question.
Luke: “The WHOLE point is that the temperature increase cannot be easily explained at all”
What makes you think that it SHOULD be possible to EASILY explain it? Can you, or anyone else, easily explain the mechanisms of DNA, or how the human brain works? These are arguably of a similar magnitude of complexity to global atmospheric etc systems, but nobody is suggesting that they can be EASILY explained.
Do you really believe that your (relatively) pathetically simplistic models can come even close to faithfully emulating these vastly complex systems – so much so that you can say that if they can’t explain it then it must be AGW?
Luke: “And gee I wonder why the PDO didn’t do similar things to temperature for the last 400 years”
How are you so sure it didn’t? Oh, I see, they actually measured global temperatures 400 years ago, did they?
Well Petey pooh you see – there’s this thing called science – which isn’t content with “shit happens” or “natural” or “recovery from LIAs”. Your use of “pathetically” and “simplistically” is purely rhetorical and BTW gonzo, the models are not might mine.
PDO and temperature – nah ! A thing called “other evidence”.
Yes Luke but for the first time in history we have fantasists claiming we have changed the status quo and that droughts, floods, hurricanes and melting poles etc are caused by AGW.
Problem is their idiotic predictions are starting to turn against them and thousands of sensible scientists are challenging their fundamentalist claptrap.
Needless to say not a scrap of evidence proves their case, so the waste of billions on this nonsense will hardly change the climate back to some past nirvana.
BTW when did the planet experience this wonderful period in times past?
No – you’re the denialist fantasist. The evidence mounts and all you’re doing is going “but but but …”.
And did we have 6 billion to 9 billion humans with 30 days food supply anytime before in history. No.
Thousands of sensible scientists challenging – LOL – you mean uninformed dickheads, egotists and shonks. If they were any good mate they’d be publishing.
Neville; Luke has raised again the question of depth in denialist camps.
When Peter asks “Can you, or anyone else, easily explain the mechanisms of DNA, or how the human brain works? then goes on “These are arguably of a similar magnitude of complexity to global atmospheric etc systems, but nobody is suggesting that they can be EASILY explained”, I can recall a conference of medical scientists where some of our team leaders gave lectures on the research around p channel phenomena and cell dynamics that were very familiar in electro – chemical terms and quite suited to workshop personnel.
At the same time I was witness to routine neurone cultures that quickly grew into webs that appeared to exhibit basic communication between nodes before other experiments on those most lively brain cells began. However much depended on the prep and the medium for the whole thing to kick in.
I often say where there is a will there is a way, so be careful how you try to put other observers and their appreciation down.
With the passing of Michael Crichton, who besides being a famous author was a Harvard medical graduate and academic, I suggest those who genuinely believe in the scientific method read his Cal Tech lecture from 2003. It expresses most chillingly the sorry mess that science has become, corrupted as it is by politics and advocacy groups:
http://www.michaelcrichton.net/speech-alienscauseglobalwarming.html