Categories
Climate Change Impacts

Dr Jennifer Marohasy ignores the climate science

Jennifer Marohasy’s article in the Weekend Australian newspaper (23/8/2008) is yet another installment in the ongoing saga of Australian non-greenhouse theorists (‘sceptics’) attempting to discredit, at least in the eyes of the general public, the conclusions of Australian climate science. But one wonders why Institute for Public Affairs supporters choose to give their imprimatur to such risky advice.

In contrast to Dr Marohasy’s piece, a robust discussion of rainfall trends their relationship to the anthropogenically driven component of global warming (AGW) must involve some aspect of risk and uncertainty. Such uncertainty can be amplified (either way) to suit supporters or detractors of the evidence underpinning global warming – and hence influence actions required to avoid dangerous climate change. However a fair and robust case for risks involved in the AGW case should be put explicitly, instead of simply pretending that such detailed advice did not exist.

The basic problem with the Australian temperature and rainfall graphics used in the Marohasy article is the issue of averages and the practice of ‘smearing’ the statistics. For instance, if we examined the time series of Australian rainfall, the immediate conclusion might be that there is no trend, or even a slight upward trend, over the entire time span. However, this continental-wide data averages over both a wetter north-west and a drier eastern, south-eastern and south-western Australia. Such an average can blur very significant and environmentally important regional trends.

Indeed if things are “so average” and of little concern, why has the Australian media been full of drought stories for the last 5 years? So, on to the basics…

Marohasy presents the Bureau of Meteorology time series for eastern Australia and the Murray Darling Basin (with regional boundary definitions here).

A quick regression will show the wet 1950s and 1970s and an overall slight trend upwards. Equally, any analysis since 1950 will bias the trend downwards, relative to the whole series. The presence of the longer-term effects on Australian rainfall from oceanic shifts, such as the Pacific Decadal Oscillation (PDO) and Interdecadal Pacific Oscillation (IPO), make the analysis of this situation, and the teasing out of the AGW influence, a complex matter.

However consider these three sequences (here, here and here). Note that any broad-scale analysis of eastern Australian rainfall since 1900 is comparing a wetting trend for NSW with a drying trend for QLD. As such, a wet and dry pattern is confounded the time series graphs given in the hyperlinks above. But any trend in the spatial analyses since 1950 show an increasingly severe drying trend in eastern Australia and the Murray Darling Basin.

Now, the Murray Darling Basin itself covers a vast area – so what has been happening in recent years in the Basin itself? An excellent summary can be had here. Six year decile analysis from Figure 1 and eleven year decile analysis from Figure 3 of the hyperlinked PDF show the major areas of the Murray headwaters to be in the lowest decile – and for some areas, it is the worst on record.

The multi-year analyses are most important for analysing water resources with respect to ‘drought for irrigation’ (as compared to agricultural drought of rain-fed pastures and crops). Antecedent conditions are very important. Because droughts progress over years, it takes a prolonged period of rainfall or a massive rainfall event to break them. Dry catchments need to soak up large volumes of water before substantial runoff occurs, and some soils can be become hydrophobic, resisting infiltration of rainfall.

The report also quotes:

“Maximum temperatures for the Murray-Darling Basin (and indeed for the whole of Australia) over the past six years were also at record levels, averaging 1.3°C above the long-term (1961-1990) average.”

Warmer temperatures can directly increase evaporation rates, and also affect the water vapour transport within soils themselves, further adding to the evaporative demand.

All this comes to a head in Wendy Craik’s report to Outlook 2008 of the situation within the Basin  Slides 4, 5 and 6 vividly illustrate the severity of the situation. Modelled inflows for the current drought sequence are worse than the famous Federation drought. This is further emphasised in the latest July 2008 drought update. This chronic lack of irrigation water to cotton growers, rice growers and the diverse Murray River irrigated agriculture is well known by the industries involved. Across the Basin cereal growers have had bad seasons and good seasons in the same period. Receiving a planting opportunity from adequate and timely rainfall is the key factor.

Slides 4, 5 and 6 from Wendy's Craik's MDBC presentation

The Brisbane River catchment which supplies the Queensland capital with water has shown similar problems, with the City only recently coming off level 6 water restrictions. The Brisbane region has seen massive expenditure on water recycling, water grids and desalination, with new dams being planned for construction.

The following analyses show worst-on-record inflows for the Brisbane River catchments above Wivenhoe dam. So south-east Queensland has also experienced a parallel situation to that of the Murray Darling Basin.

As for Marohasy’s claim of a less-than-dire salinity situation in her newspaper piece – this issue was comprehensively debated when she raised it previously. So one must ask, if she was seeking an honest and open debate, why has she chosen not to drawn attention to this much more complex picture?

Hard nosed observers may also speculate that the record-breaking droughts described above may not in fact be unprecedented over even the last few hundred years. Without reliable rainfall and run-off measurements, it is impossible to be sure. Indeed, the Burdekin seemed to have experienced very low flows for the 1760s to 1780s, based on proxy records from coral skeletons.

No scientist disputes that the Earth system is variable, and that the further back in time one looks, the greater amount of the full range of natural variability will be experienced. The point is not whether there are many influences involved with climate change – there indisputably are. The question of interest with the current drought is whether the fingerprint of AGW can be detected.

NASA image of the Pacific Ocean in April 2008 showing La Nina and Pacific Decadal Anomalies.
NASA image of the Pacific Ocean in April 2008 showing La Nina and Pacific Decadal Anomalies.

Australian climate science is documenting significant changes in the El Niño Southern Oscillation (ENSO), the Indian Ocean, southern hemisphere circulation and Tasman Sea temperatures. Although have seen a trend towards El Niño dominance and a weakening of the Walker circulation, there is still controversy as to the effect of global warming on ENSO processes. However Power and Smith now suggest that global warming needs to be taken into account in the formulation of ENSO indices.

There is a substantial case for linking anthropogenic impacts of Antarctic stratospheric ozone depletion (due to CFCs) and greenhouse warming on the southern hemisphere atmospheric circulations and Australian climate. For instance:

Thompson, D.W.J. & Solomon, S. (2002) Interpretation of recent Southern Hemisphere climate change. Science 296, 895.

Shindell, D.T. &. Schmidt, G.A. (2004) Southern Hemisphere climate response to ozone changes and greenhouse gas increases. Geophys. Res. Lett. 31, L18209.

Cai, W. (2006) Antarctic ozone depletion causes an intensification of the Southern Ocean super-gyre circulation. Geophys. Res. Lett. 33, L03712.

Cai, W. & Cowan, T. (2006) SAM and regional rainfall in IPCC AR4 models: Can anthropogenic forcing account for southwest Western Australian winter rainfall reduction? Geophys. Res. Lett. 33, L24708.

The south-east QLD drought analysis also mentions the feedback effects of land clearing. Preliminary modelling studies indicate that past land-use changes in Australia, associated with major clearing, may have also suppressed rainfall over eastern Australia and contributed to hotter, more severe droughts during recent El Niño events.

The joint CSIRO – Bureau of Meteorology South-east Australian Climate Initiative attributes a role of global climate change in the drying of south-eastern Australia via specific changes to the sub-tropical ridge (STR):

“The intensity of the STR also peaked in the 1940s at the time of the previous dry decade in the south-east. By and large during the 20th century, the long-term evolution of the intensity of the STR follows the curve of the global temperature of the planet. This relationship gives a high likelihood that the current rainfall deficit is linked to the global warming of the planet, through the intensification of the STR.”

Drs Wenju Cai and Tim Cowan have further dissected the climatic reasons for the decline in Murray flows and the impacts of temperature on the water balance:

Cai, W. & Cowan, T. (2008) Evidence of impacts from rising temperature on inflows to the Murray-Darling Basin. Geophys. Res. Lett. 35, L07701.

Cai, W. & Cowan, T. (2008) Dynamics of late autumn rainfall reduction over southeastern Australia. Geophys. Res. Lett. 35, L09708.

To quote:

The 2001–2007 Australian drought was the hottest on record, with inflows to Australia’s longest river system, the Murray-Darling, reaching an historical low. Here we examine the relative importance of rising temperature and decreasing rainfall over its catchment, the Murray Darling Basin (MDB). Although annual-total inflow is more sensitive to rainfall over the southern MDB, where rainfall since 2001, has been the lowest on record, this alone can not explain the observed inflow decline. A relationship exists between inflow variations and fluctuations of temperature not associated with rainfall in the austral winter and spring: a rise of 1°C leads to an approximate 15% reduction in the climatological annual inflow. Our results provide strong evidence that rising temperatures due to the enhanced greenhouse effect have a strong impact on southern Australia’s water resources, in addition to any reduction in rainfall, and project a long-term decline in inflows to this river system as the greenhouse effect continues.

The wetting trend of north-western Australia has been linked to remote Anthropogenic Asian aerosols, such as from the burning of Indonesia’s tropical forests, although there remains considerable uncertainty on this point.

Thus a case emerges of: (i) severe rainfall declines in parts of eastern Australia, (ii) record low inflows in major river systems of considerable economic, social and ecological importance; and (iii) a growing body of peer-reviewed climate science that, at the very least, implies some involvement of anthropogenic factors in the current drought – an influence likely superimposed upon a complex of natural variability.

On a non-drought related point – it’s fascinating that sceptics like to use, when it suits their purpose, the same temperature series they discredit to prove their latest “cooling” idea. Surely they can’t have it both ways. The excellent Wood-for-Trees website allows one to plot, compare and contrast, in as many ways as you can imagine, the relative differences between the two ground-based and two satellite temperature analyses. The trends are very similar, with the major differences being in how GISTEMP treats averaging of stations across the Arctic, and in the different baseline periods used to compute the ‘temperature anomaly’.

It rather strange that the Marohasy article implies some dependence of the Bureau of Meteorology on the UK East Anglia and Hadley Centres for temperature trends. Perhaps she does not realise that for the local Australian situation this is not so at all – the Bureau has its own high quality data sites which do not include capital cities – and Australian analyses (here and here) of temperature trends.

Both the differences between different climate analyses, and the management of Bureau of Meteorology station data, are explained by Andrew Watson (BOM) and myself in the Climate Change Q&A seminar 1: “Is the Earth Warming?”.

A deeper question to emerge from the above is this: exactly whose interest is being served by the deliberate attempt of various non-greenhouse theorists to blur and fog this debate, the latest example of which is the Weekend Australian piece by Dr Marohasy? Why have they not openly and honestly provided a full disclosure of the rainfall trends, inflows and statistics behind the story? Why the need for a sleight of hand, in which the data are very selectively presented and interpreted? Most importantly, why has the latest peer-reviewed scientific literature not been mentioned?  A much more serious analysis on this point is needed.

[Thanks to an anonymous contributor for their very helpful contributions to the above piece]

Add to FacebookAdd to NewsvineAdd to DiggAdd to Del.icio.usAdd to StumbleuponAdd to RedditAdd to BlinklistAdd to Ma.gnoliaAdd to TechnoratiAdd to Furl

By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

62 replies on “Dr Jennifer Marohasy ignores the climate science”

Barry said : “A deeper question to emerge from the above is this: exactly whose interest is being served by the deliberate attempt of various non-greenhouse theorists to blur and fog this debate”.

Surely you are not the only repository of all true wisdom? Jen. Marohasy has no less interest than you in the future well-being of all Australians.

Barry again: “…the latest example of which is the Weekend Australian piece by Dr Marohasy? Why have they not openly and honest provided a full disclosure of the rainfall trends, inflows and statistics behind the story? Why the need for a sleight of hand, in which the data are very selectively presented and interpreted?”

That is simply untrue. Jen merely produced data freely available to all including you. Where was it incorrect? Tellingly, you do not say.

Like

That is simply untrue. Jen merely produced data freely available to all including you. Where was it incorrect?

Cherry-picked data isn’t incorrect, Tim, nor did Barry say it was incorrect. It’s just … cherry-picked.

Like

A nice piece, Barry, though I reckon you’re drawing a bit of a long bow with your last rhetorical question. How often does any scientific piece in a major newspaper get to refer to the primary literature?

Which brings me to the point that surely you can agree with Jennifer on: In general the public debate should involve a lot more looking at the actual data (cf. business & economics reporting) than the ‘meta-debate’ we so often see currently, and specifically that “ultimately, good policy is going to require that a much larger percentage of Australians have a higher level of scientific literacy.”

Like

A substantial analysis, Barry.

As I have maintained previously, Jennifer is basically a corporate shill. She is employed by a think tank funded by some major global corporations such as Monsanto and BHP, and local corporations like Gunns and Murray Irrigation. The tenor of her analysis is in sympathy with her patrons, obviously, so she is against regulations that will affect her patrons’ access to irrigation, or tax carbon emissions, and she is in favour of regulations freeing up the use of Monsanto GM food products. She’s paid to make their case for them. Hence her position as a leading environmental skeptic in Australia.

“A shill is an associate of a person selling goods or services or a political group, who pretends no association to the seller/group and assumes the air of an enthusiastic customer. The intention of the shill is, using crowd psychology, to encourage others unaware of the set-up to purchase said goods or services or support the political group’s ideological claims.”

As a scientist she has little credibility.

Like

Barry your article says seek and ye shall find yourself funny stuff. …….
e.g.
“….. make the analysis of this situation, and the teasing out of the AGW influence, a complex matter.”
and …
“The question of interest with the current drought is whether the fingerprint of AGW can be detected.”

This is without doubt theology masquerading as science. Like, just go back to this set of graphs at …..

Please just try a little harder to describe scientifically if possible, what you have found out about stratospheric cooling that is supposedly your validation for AGW and your so called ” fingerprint” instead of retreating to your cosy tiny playpen to avoid this request.

Like

Our Jennifer is on dangerous ground suggesting Australians need to be better educated in science – if they were, they’d ignore her for a start.

Like

Keiran – 9
Over the years it has become obvious to me that, if you want to know where the disingenuous are coming from, always look to the accusation they make about you.
Thus “This is without doubt theology masquerading as science” tells us which ideology is driving your denialism – and it ain’t science!

Like

Another David (@11). Sweet! I think they’ve been confusing us with each other over at Our Jennifer’s little blog.

Like

Go the Daves! Actually … don’t get me talking complex numbers either, climate change science is complex enough – makes me wonder why the trolls persist, they want to ‘play scientists’ but are not willing (or capable) to do the hard yakka.
For simplicity, I (@11) should now delineate myself from you (@13 et al) by the tag DavidK.

Like

Seriously though, we do have a problem in attracting students to science. And contrary to popular belief (amongst the denialist blogosphere) we ain’t in it for the money.

Like

Ok, so now you’re accusing Jennifer Marohasy of ‘cherry picking’ but aren’t you doing the same by only selecting a small part of Australia? I’m sure you could come up with an even more alarming set of figures if you narrowed it down to an even smaller area. When we are talking about a ‘world wide problem’ why aren’t we looking at world wide statistics?

For each area, city, country that you choose to show is suffering from below average rainfall I’m sure we could fine one that is enjoying/suffering from above average rainfall.

Yes parts of Australia are drier and other parts are wetter…. we (us skeptics) don’t deny that weather changes locally and globally but we are yet to see PROOF that we are ‘going to hell in a handbasket’ and that we have caused it by CO2 emissions.

Like

but we are yet to see PROOF that we are ‘going to hell in a handbasket’ and that we have caused it by CO2 emissions.

Helps if you open your eyes.

Oh, and somebody who needs to use the word ‘proof’ (especially in CAPITALS) really doesn’t understand how science is done. We are talking risk assessment here, not absolute proof of the kind you find in mathematics, that kind of proof does not exist in the natural sciences.

Like

Owen, of course it’s a worldwide problem and we do look at worldwide stats. Have a gander at this link and tell us what you don’t understand about the not-so-pretty graphs.

http://www.cru.uea.ac.uk/cru/climon/data/themi/

It would be helpful to locals (wherever they are situated) to have more regional analyses (just ask the farmers). There really is no problem with Barry’s synopsis.

Put simply, if you put energy into a system, it heats up. A warming world will have more moisture in the air and it will fall out as rain or snow – somewhere. Yep, there will be winners and losers (especially in the short term) but remember, we have to look at the bigger picture.

Oh yeah, science is not analogous to proof beyond reasonable doubt (the scientific process is more about probabilities).

Like

Tim Curtin,

Nice to see you back here. Can I ask you to:
1. Actually confirm that your paper has been formally accepted for publication in Energy and Environment (you still haven’t explicitly provided this confirmation as far as I can tell);
2. Let us know how your Nature rebuttal is coming along. When can we expect to see a draft / a confirmation that it has been submitted to Nature?

Thanks!

Like

Now it’s funny that there is no drought as I was sure my tax dollars were going out to support zillions in drought aid that doesn’t seem to stop.

National drought relief expenditure 1992-1999 $698,600,000 – Table 6
http://www.environment.gov.au/soe/2001/publications/theme-reports/atmosphere/atmosphere02-14.html

Australian Government expenditure on drought assistance in the five years to June 2006 is more than $1.2 billion. $430 million in additional drought assistance – 17 September 2007. Here’s the media releases …

http://www.daff.gov.au/agriculture-food/drought/media/media_releases

Despite historic $12.9bn to save River Murray, it may be too late
http://www.news.com.au/adelaidenow/story/0,22606,23957464-5006301,00.html
13 May 2008
DAFF08/057B
Farmers will continue to receive assistance from the effects of drought after the Rudd Government announced it is maintaining Exceptional Circumstances (EC) support in 2008-09.
Minister for Agriculture, Fisheries and Forestry Tony Burke said $760.9 million had been committed for EC assistance in the 2008-09 financial year.
“The Rudd Government is standing by our farmers, many of whom are still doing it tough, trying to manage their businesses and support their families in drought,” Mr Burke said.
“Despite some rain earlier this year in parts of Queensland and NSW, some parts of Australia are in their seventh consecutive year of drought.
“There are currently 84 Exceptional Circumstances-declared areas across the country and an additional 14 areas that are interim-declared – more than 69% of Australia’s agricultural land.”
http://www.maff.gov.au/media/media_releases/may_2008/rudd_government_continues_ec_drought_assistance_for_farmers

Drought assistance extended in SA region
http://www.maff.gov.au/media/media_releases/june_2008/drought_assistance_extended_in_sa_region
Drought assistance extended for Queensland regions
http://www.maff.gov.au/media/media_releases/june_2008/drought_assistance_extended_for_queensland_regions
Details of national review of drought policy released

http://www.maff.gov.au/media/media_releases/june_2008/details_of_national_review_of_drought_policy_released

19 August 2008
DAFF08/105B

The Rudd Government today announced it will extend assistance for 32 drought-declared areas in NSW, Victoria, Western Australia and South Australia.

http://www.maff.gov.au/media/media_releases/august_2008/federal_government_accepts_advice_on_drought_declarations

Like

So some areas have had 300 years worth of their i in 15 years of assistance. This is a problem costing billions of dollars. Serious analysis and best advice is needed.

It’s not only government – farmers and rural industry need to consider whether to invest, retreat, diversify or maybe move north or to South America. Or develop whole new farming systems. Drought resistant biotechnology investment? The MDB Commission needs to work out how to allocate water resources.

Australian’s are slowly waking up that maybe things are changing around them. There is no 100% certainty in the issue of AGW attribution but the papers in the lead article point to a meteorological mechanistic understanding how a variety of anthropogenic influences are moving rainfall bands in Australia. For my money there is some anthropogenic effect and some natural.

There are some major changes going on in the southern hemisphere. Sceptics need to open their eyes and take in a wider view.

This is an issue about risk management. Automatically putting the knife into the science involved with this issue because of dissatisfaction with a carbon tax debate does a disservice to scientists trying to unravel the problem and the rural communities involved. With or without a carbon tax this is a serious issue !

So small movements in climate may be critical for our agriculture. Sea surface temperature anomalies which cause droughts or floods are only 0.5 to -2-3 degrees. Doesn’t take much.

Of course it might rain tomorrow – let’s hope it does. But how long till the next drought? This malaise has been going on now since the early 1990s. See Figure 3 here http://www.bom.gov.au/climate/current/statements/scs14.pdf This pattern has been building a long time.

It’s pretty obvious the politics here are to stop any changes in the status quo – any reevaluation of farming risk, drought aid, or water allocations. Why?

So the rest of us in Australia have to work out how long we’re prepared to prop up this issue with tax dollars ?

Like

Dr Dave, impertinent as ever to one old enough to be your father!
How would you rate my chances of success, given I have no paid academic affiliation, and no affiliated co-authors, it seems 7 is about the norm. Are you available? If so, I will accelerate my anxiously awaited paper. Meantime I do now have three up-coming peer-reviewed papers, it is for you to keep a look-out as to when and where they will appear.

Like

Thorough analysis, Barry. Marohasy’s careful exclusion of inconvenient data is testimony to her utter cynicism, and her insinuation that Stern confuses model output with observed data is contemptible.

Like

Barry: your extract is a classic GIGO: Nowhere in the extract below do the authors admit the existence of abstraction from the MD catchments via dams, upstream offtakes, and cretinous greens installing watertanks with their ability to prevent any rain ever reaching the MD. “The 2001–2007 Australian drought was the hottest on record, with inflows to Australia’s longest river system, the Murray-Darling, reaching an historical low. Here we examine the relative importance of rising temperature and decreasing rainfall over its catchment, the Murray Darling Basin (MDB). Although annual-total inflow is more sensitive to rainfall over the southern MDB, where rainfall since 2001, has been the lowest on record, this alone can not explain the observed inflow decline. A relationship exists between inflow variations and fluctuations of temperature not associated with rainfall in the austral winter and spring: a rise of 1°C leads to an approximate 15% reduction in the climatological annual inflow. Our results provide strong evidence that rising temperatures due to the enhanced greenhouse effect have a strong impact on southern Australia’s water resources, in addition to any reduction in rainfall, and project a long-term decline in inflows to this river system as the greenhouse effect continues.” Garbage!

Like

DavidK,

“Have a gander at this link and tell us what you don’t understand about the not-so-pretty graphs.”

The correct ones show June ’88 warmer than June ’08.

These don’t.

Barry,
Following the record 1974 floods in SEQ, since 1976 no cyclone has crossed the Qld coast south of the tropic of Capricorn where previous they regularly did. Sometimes several per year.
There has been a big increase in cyclones on the NW coast since then and it was said to be due to the PDO.
This was not something that happened progressively in correlation with increases in ACO2,it was very sudden as was the world’s temperature increase at that time.
It was a cyclical event that is beginning to revert.

Like

Spangled Drongo – try not to ignore ALL the other evidence that staring you in the face. How about NW cyclones from a globally warmed Indian Ocean – PDO??

– and no Queensland cyclones from shear forces put across the formation regions by an anthropogenically changed southern hemisphere anti-cyclones, more El Nino events and less on-shore flow? Just jumping on unpredictable Pacific oscillations is too simplistic.

As has been sad – just because the Pacific shows cyclical statistical behaviour – doesn’t mena those cycles actually exist in reality. May just be artifacts or a bunch of El Nino and La Nina events.

All of which is why you have to get beyond correlations, into the models and meteorological mechanisms. Read the papers.

Like

“Indeed if things are “so average” and of little concern, why has the Australian media been full of drought stories for the last 5 years?”

Hmm, perhaps because we’re running out of water for people and irrigation because the greenies won’t let us build dams anymore? As Jennifer’s graphs show, rainfall in Australia is pretty much business as usual. Up overall. Up a bit more in some places, down a bit in others. Stuff all real change.

“Equally, any analysis since 1950 will bias the trend downwards, relative to the whole series.”
“But any trend in the spatial analyses since 1950 show an increasingly severe drying trend in eastern Australia and the Murray Darling Basin.”

Ah… this would be that ‘cherry-picking’ everyone is talking about. Let’s date all rainfall analyses in Australia from 1950, the wettest part of the century, and manufacture a downward trend. CSIRO do it all the time to generate this rainfall beat-up. No better than the ‘warming stopped in 1998 crowd’ really.

” situation, and the teasing out of the AGW influence, a complex matter.”

That’s because it ain’t there.

“Warmer temperatures can directly increase evaporation rates”

Wrong. Look up CSIRO’s own research on the ‘pan evaporation paradox’. Evaporation rates are decreasing around the world.

Like

That was kind of my point wasn’t it? It was amusing that you mention “any analysis since 1950 will bias the trend downwards” then the very next paragraph come in with “spatial analyses since 1950 show an increasingly severe drying trend”. Warn against doing something then do it straight away. Besides, it wasn’t aimed particularly at you, more at BOM and CSIRO who make all of their ridiculous rainfall statements ‘compared to the 1960-1990 average’ or some such.

There is nothing anomalous about current Australian rainfall, just a return to the drier conditions experienced in the early 20th century. We hear so much about the current ‘drought’ because a) people confuse an increase in demand (increasing population, etc.) with a shortage in supply… and b) because our farmers thought the wet than usual period would go on forever.

How can you accuse Marohasy of somehow misrepresenting the picture by simply presenting the facts on Australian rainfall? Even the Murray-Darling is still experiencing rainfall in excess of the 1900-1940 period, see:

And you do realise evaporation is mainly driven by wind-speed right?

Like

Tim,

Three in press peer reviewed papers now? You must have had a good week given that on 16th August you said “The second item on the listing of the more recent papers on my homepage has been accepted, as noted in the first item, another is still under peer review, and a second hopefully soon”.

I am confused?

Like

As for temperatures NOT affecting evaporation – well that’s not right either.

Evaporation is a combination of factors – solar radiation, wind run, vapor pressure (~humidity) and temperature. See http://en.wikipedia.org/wiki/Penman-Monteith Already, there are suggestions that the anomalously high temperatures recorded in recent years have exacerbated the impacts of the recent drought [e.g., Nicholls, 2004] But yes temperature is only one factor. And “in general” one make might an assertion that it is of lesser importance i.e. a warmer Darwin has less evaporation than Alice Springs with less cloudiness and lower humidity. However perhaps warmer soils also change water vapour transport which is not reflected in evaporimeters. (Rose 1968)

However, back in the MDB – Cai and Cowan’s paper has provided some evidence that reductions in rainfall alone are not fully responsible for the lack of runoff with high drought temperatures being a contributing factor.

As suggested in the comments above, recent research has shown decreasing long term TRENDS in evaporation rates which attribution studies have attributed primarily to reductions in wind run with some regional contributions from decreased solar irradiance (global dimming and cloudiness) i.e. the classic work of Roderick et al. (2007) http://www.rsbs.anu.edu.au/Profiles/Graham_Farquhar/documents/255RoderickRoFaHopanattribGRL2007.pdf Broadly speaking that wind run decline explains the long term trends in evaporation better than solar radiation, vapour pressure deficit or temperature.

But again in the details from the above paper –

Previous research reported a trend in pan evaporation rate, averaged over 61 Australian sites for 1975–2002, of _3.3 mm a_2 [Roderick and Farquhar, 2004]. This was later updated (an addendum is available from the authors) to _3.2 mm a_2 to account for the installation of bird guards. The trend for 1975–2004 over the same 61 sites is lower at _2.4 mm a_2 (results not shown) because of the high pan evaporation rates during the drought conditions prevailing over much of southeast Australia since 2002.

And also Nicholls had previously reported in

http://www.ingentaconnect.com/content/klu/clim/2004/00000063/00000003/05143861

“Rainfall over nearly all of Australia during the cooler half of the year (May–October) was well below average in 2002. Mean maximum temperatures were very high during this period, as was evaporation. This would suggest that drought conditions (precipitation minus evaporation) were worse than in previous recent periods with similarly low rainfall (1982, 1994). Mean minimum temperatures were also much higher during the 2002 drought than in the 1982 and 1994 droughts. The relatively warm temperatures in 2002 were partly the result of a continued warming evident in Australia since the middle of the 20th century. The possibility that the enhanced greenhouse effect is increasing the severity of Australian droughts, by raising temperatures and hence increasing evaporation, even if the rainfall does not decrease, needs to be considered.”

But the wind run gotcha perhaps is from “Detecting and attributing Australian climate change: a review” http://www.bom.gov.au/amm/200603/nicholls_hres.pdf

which says “Rayner (2006) demonstrated that, apart from the northwest of the country (where increased cloudiness associated with the rainfall increase may play a role), the observed decline in pan evaporation was clearly related to declines in wind speed. He further demonstrated that these wind speed declines were, in general, likely to be artificial and represent changes in instrumentation or exposure of the instruments, i.e. that the wind speed decline is not representative of widespread wind speed decline. Rayner’s results suggest that the decline in pan evaporation may be artificial, and results from local changes around the pans

Published Rayner paper here: http://ams.allenpress.com/perlserv/?request=get-pdf&doi=10.1175%2FJCLI4181.1 and again Rayner’s analysis only goes to 2002.

Leaving the last word to Roderick et al 2007 – “Whether the ‘‘stilling’’ reported here is local, i.e., attributable to changes in the immediate environment of the pans (e.g., growing trees or other obstacles progressively obstructing the air flow), or a more regional phenomenon is difficult to assess. Rayner [2007] investigated that by comparing the BoM wind observations against two alternative sources, (1) wind fields in the NCEP reanalysis, and (2) wind calculated using BoM surface air pressure observations. The results were inconclusive because the trends derived from (1) and (2) were inconsistent, and neither result was consistent with the BoM surface observations. [17] Some of the wind speed decreases reported here are no doubt due to local effects. Alternatively, the very widespread nature of the stilling is by itself some evidence of a more robust regional effect Indeed, the changes. reported here are very similar to those reported elsewhere (Table 2). Whilst largely unanticipated in the climate change impacts community, previous analyses have predicted a slowing in the overall circulation rate in tropical regions and, presumably, a reduction in averaged wind speed in those regions with greenhouse warming [Betts, 1998; Held and Soden, 2006; Vecchi et al., 2006]…………. “

So again the devil is in the details – IMO the temperature hypothesis does stack up in the recent drought with high evaporation rates to boot.

This is contrast with the assertions made in comments above.

Like

This would have to be priceless

“cretinous greens installing watertanks ”

– so Tim has just sledged every tank-installing landholder in Australia. Brilliant ! Perhaps a few people other than greenies install water tanks?

And then a very well reasoned argument against Cai and Cowan’s paper “Garbage!” – possibly not the brevity that a hopeful journal author might aspire to as a rebuttal. Garbage indeed but not from Cai and Cowan.

Drought caused by greenies stopping dam building ! LOL ! – come on blame the greenies some more – what calls for new dams by whom ?
Do you mean building expensive dams that won’t fill ? some rainfall does not equal runoff – read the lead post. Useful runoff is generated by consistent rainfall – which is missing in both the El Nino years, the neutral years (those neither El Nino or La Nina) and recent La Nina that fizzed over the MDB? 2001 to present …

If rainfall is OK why aren’t the our dams doing much better – so we have from major NSW dams – Burrendong – 20%; Copeton 20%, Darling Weir 0%; Keepit 21%; Spilt Rock 7%, Glenlyon 20%; and that’s the more “average” part of the MDB catchment. http://www.wron.net.au/DemosII/DamData/DamLevels.aspx

Cotton and rice irrigation industries in tatters.

Tim says ” Nowhere in the extract below do the authors admit the existence of abstraction from the MD catchments via dams, upstream offtakes, and cretinous greens installing watertanks with their ability to prevent any rain ever reaching the MD”

– the modelled inflows are from very well calibrated models with the current levels of infrastructure – your comment isn’t relevant the issue. It’s a simple lack of rainfall and runoff. Worst on record conditions in the Murray headwaters. Same in the recent drought in SE Qld. How simple is that Tim?

Indeed Tim if you want to go to catchment modification theories – well tree clearing for agriculture and grazing ought be giving us more runoff in one respect but perhaps changes in land surface feedbacks from land development may have also made a contribution to a warmer drier climate as this preliminary research shows.

http://www.agu.org/pubs/crossref/2007/2007GL031524.shtml

Spangler Drongo – it may well have been warmer before without CO2 – well if the “Medieval Optimum Period” is anything to go by – major ongoing droughts in the Americas, Asia, Africa according to Brian Fagan – in his recently published book – “The Great Warming” http://www.amazon.com/Great-Warming-Climate-Change-Civilizations/dp/1596913924

Perhaps there are a number of paths to a warmer world and consequences of that more severe than growing grapes in England. The current climate path is perhaps increasingly more of our own making as the papers in the lead post illustrate (if you actually take the time read them with an open mind!).

So again comes back to risk management. And risk management of the Murray Darling Basin is the issue (as well as eastern Australia more broadly and SW Western Australia) !

I totalled around $16 billion in support from my comments above.

Sceptic fog isn’t helping that process.

Like

Well done Barry on the blog. Keep up the good work.

BTW, what was most astonishing to me about the Australian piece was what was missing.
How could you talk about climate change and not show a temperature graph for OZ or the MDB. Further, why did only some of the graphs have trend lines.

BTW one thing you missed is that Jen’s article actually included the full list of recent peer reviewed climate science papers by local Australian sceptics (it seems to have zero length).

Like

I am afraid that Tim Curtin’s attention to the important question of precipitation trends in the MDB will take his energies away from the even more important task of documenting the statistical gaffes he has discovered in Domingues et al. so that he may submit his critique within the permitted time as a formal letter to Nature. Perhaps we may help.
Tim — could you share with us a bit more about how many such statistical gaffes you’ve found (as I recall, the paper is “riddled” with them) and how you intend to describe them? With some volunteer help, I am sure you can get that letter in on time.

Like

Some naive joker called David (i.e. Q&A) here is not too keen on “Australians(sic) need to be better educated in science” and contradicts himself in his next post by suggesting that i “need to do more homework, again”. lol

This David goes on to say “Try repeating … 1 + 1 does NOT = 3” which is equally silly because we do not have the “1” in the first place. Must say that trying to build fiction upon fiction may appeal to AGWers but in the real world it is phony behaviour. Whilst you bring up mathematics as a subject too, let me say that mathematicians may present as most impressive but they are not scientists. We need to consider also that trust can only be earned. i.e. Just what assumptions are made in formulae and equations for example? They may all look rather impressive but all have embedded agendas and many in fact may be quite fictional.

Like

Keiran, your comprehension (lack thereof) is astounding, just as much as your minuscule understanding of the sciences.

If you care to read the posts and comments more carefully, you will see it is Jennifer Marohasy that is saying “Australians(sic) need to be better educated in science”. You should take her advice … I know it will be an up hill battle for you when you think 1 + 1 = 3

So yes, you need to do your homework.

Btw, your guru over at Climate Audit is a mathematician and you are right, he is not a scientist. I concur with you, Steve’s “formulae and equations may look rather impressive but all have embedded agendas and many in fact may be quite fictional”.

Like

DavidK, it is this David joker suggesting dangerous grounds for Australians to be better educated in science …… which is quite the opposite to Jennifer Marohasy. Comprehend?

The other point you make exposes your very own insecure worship mindset for high priest gurus. Quite simply i suck up to no one, never have and never will. No admiration society with moi …. get it? Now just tell me what your “1” represents if it is not pure fiction.

BTW …. Why is it i cannot get this validation or this so called ” fingerprint” for AGW from anyone here?

Like

Keiran, Keiran, Keiran. You’ve confused the two Daves, who happen to agree with each other (I think – hope I’m not putting words in your mouth, DavidK) that Our Jennifer is being disingenuous (yet again) by suggesting Australians need to be better educated in the sciences. The point I made, which has obviously gone right over your head, is that an Australia filled with scientifically literate citizens would see Marohasy for the fool (or liar) that she is, and ignore her. This actually seems to be pretty much happening, which is good news.

We were also having a brief, amusing meta-discussion (or at least I was, and I’m sure most readers got it even if you didn’t) about rounding errors in limited precision arithmetic. Please let me know if you need this one explained to you.

Like

David, he’s so confused every David he meets from now on will start the poor old lad babbling and fitting. Wonder what all the other Daves think?

Like

So we have a David and another David and a DavidK and a Dr David ……… all speaking as one i suppose and all avoiding what this initial assumption “1” represents. If it is not pure fiction then this doubly-doubly of Davids should come out and explain themselves clearly and scientifically. ‘Corse you may need to seek permission from your high priest guru first. lol

Like

what I find interesting about Marohasy is that she is espousing arguments that she herself has admitted are wrong.

A couple of years ago on her blog I said:

“So how about either a defense of Bob Carter’s “warming stopped” argument, refuting the lengthy rebuttal I gave or an acknowledgment that it is not a reasonable point?”

to which she replies:

“I disagree with Bob on the issue of warming. I see a general and continual increase in temperature in the global and Australian data – and I have also noted that James Hansen’s predictions are more-or-less on track.”

See this post for details and source:
http://scienceblogs.com/illconsidered/2008/08/making_lemonade.php

Like

Keiran,

Would you care to enlighten us on why you think the stratosphere is cooling and the troposphere is warming? Hint: a ‘fingerprint’.

Of course, you have to believe these things are happening in the first place (this picture may help).

Oh, please help us by citing your primary reference sources.

In your twilight hours, back to your homework … repeat 100 times: 1 + 1 = 2
Once you appreciate this concept … well, then we can move onto algebra.

Like

Affirmative, Dave, I read you, we have stratospheric cooling ……….. but this has been going trendless for ten years. To help you with the causality i’ll generously give you a hint. Have a look at the three major volcanic events, Agung in 1962, El Chichon in 1982 and Pinatubo in 1991 in these charts and tell me what you FIND. …. because it is find and ye shall seek NOT your seek and ye shall find yourself funny stuff.

Daisy, Daisy, give me your answer do. I’m half crazy all for the love of you. It won’t be a stylish marriage, I can’t afford a carriage. But you’ll look sweet upon the seat of a bicycle built for two. Please just try a little harder to describe scientifically what you FIND.

Dave, I think you know what the problem is just as well as I do.

Like

Kieran said:”Affirmative, Dave, I read you, we have stratospheric cooling ……….. but this has been going trendless for ten years. To help you with the causality i’ll generously give you a hint. Have a look at the three major volcanic events, Agung in 1962, El Chichon in 1982 and Pinatubo in 1991 in these charts and tell me what you FIND.”

I found that volcanoes cause tropospheric and stratospheric cooling for a couple of years.
I found that most of the time volcanoes were not acting, and yet the stratosphere is cooling over
the period of 40 years shown, and the troposphere is warming. Just as GCMs predict for the behavior of both volcanoes (blocking visible light, i.e. energy absorption in the stratosphere and troposphere) and increasing CO2 (increasing emission in the atmosphere, the increased emission toward the ground heats up the troposphere, the increased emission toward space cooling the stratosphere).

Like

Keiran,

This is getting quite tiresome. It is obvious you are having trouble understanding the HadAT graphs, may I suggest you look at the following links (volcanic eruptions are more clearly defined too);

Click to access update_report.pdf

Click to access Mears_and_Wentz_TMT_TTS_TLS_submitted.pdf

http://www.atmosphere.mpg.de/enid/20c.html

http://www.sciencemag.org/cgi/content/full/314/5803/1253

To try and bring this thread back on topic somewhat, try this (Carl Mears again)

http://www.sciencemag.org/cgi/content/full/317/5835/233

I know what the problem is Keiran, you won’t do your homework.

Like

Just what do you think you’re doing, Dave? I have asked YOU to have a look at the three major volcanic events, Agung in 1962, El Chichon in 1982 and Pinatubo in 1991 in these charts and tell me what you FIND. You have not found anything and presumably have no ability to explain in your own words why stratospheric cooling ceased 15 years ago despite some moderate warming and increased CO2 levels.

Look Dave, I can see you’re really upset about this. I honestly think you ought to sit down calmly, take a stress pill, and think things over. Your links prove nothing at all about the effect carbon dioxide might play with stratospheric cooling. Colourful model maps at a particular time …. like 15 plus years ago are arbitrary and selective … and simply indicate that you are seriously challenged when it comes to reading these simple hadobs.metoffice charts.

Dave, I’ve still got the greatest enthusiasm and confidence in this mission that says behaviour is the control of perception. And I want to help you if possible, to take control of YOUR very own behaviour. This mission is too important for me to allow you to jeopardize it.

[Keiran – don’t be sniping with your allusions to 2001 and HAL – just play the ball]

Like

Moderator, I am putting myself to the fullest possible use, which is all I think that any conscious entity can ever hope to do. A bit of fun, humour and play surely is not offensive. Let me say something about play. Play, although hard to define, is what I tend to do most and seemingly all lacking the extrinsic as well as any reduced uncertainty.

My family and friends often wonder why I post on various Forums and perhaps the main reason is the wealth of funny stuff and subroutines that I get to play with that otherwise would never be tried. There are cognitive benefits in play and an enrichment that enhances behavioral flexibility. Picasso and Mozart played all their lives …….. and science as you must know is very much play too. The problem that one may detect at times is that there are some unfortunates that do not play, that are maladaptive, fragile, inhibited, stressed or whatever? However, let’s try to get the essential features of intrinsic motivation where first one should PLAY before the enrichment of find and ye shall seek.

[You miss the point – I don’t mind word play, I just dislike it when it is effectively an attack on the person who’s argument you are disagreeing with (in this case Dave, hence the Bowman “wordplay”), rather than a critique of their argument’s logic]

Like

Keiran

Are you an atmospheric physicist specialising in volcanic perturbations and their effect on global and hemispheric temperature, pressure and chemical anomalies at varying altitudes and latitudes?

Am I? No. I am a trained scientist in things H2O – hence my interest in this thread.

As a scientist, when other scientists (who are expert in their field) say something, I listen – I will question, but I mostly listen. I gave you links in response to your questions – have you even read them, or in fact, understood them? What is contained in them (there are many others) are answers to your questions.

Why do you need an answer from me in particular, when others can give it more succinctly?

_____

Yes Barry, Hal 9000 plays word games – we all do. Too many people play the messenger, not the message, it is disturbing.

Like

Barry is overly focused on this man vs message but for myself as a general nobody here on Barry’s new blog, it is the message vs evidence and that is why i keep saying behaviour is the control of perception. i.e. Don’t be a prize stoopid by asking for a second opinion because it should be show me the bluddy evidence and then ask if there is even better evidence. e.g. I’ve asked numerous times for some AGW believer to examine these simple hadobs.metoffice charts and tell me what they FIND. It is not an argument as such but a request which may even be a test for some AGWers who see this stratospheric cooling as “my” incriminating fingerprint.

Mr Moderator, it is more than trivial word play when i say FIND and ye shall seek as opposed to this target training pseudo-science of seek and ye shall find exactly nothing …… but yourself. I believe that good scientific knowledge is learned, by studying and FINDING those things that do not fit what you expected. e.g. We want the observed details, and want to know WHY this particular data set is not conforming to the conventional theories.

DavidK, I am simply amazed that a bit of HAL talk in good oz humour could set off an alarm with some supposedly intelligent people. Cripes, what’s the world coming to?

Like

As long as Jennifer’s articles generate this much interest The Australian will keep printing her pretend science. No-one who really knows anything about the subject takes her seriously but if it creates debate and controversy it will sell papers and that is probably The Australian’s bottom line.
I’ll go on taking my climate science from the professionals – the fluff and puff that Jenny and her ilk parade as reasonable doubt is remarkably unimpressive – well it’s impressive to those who are uninformed or misinformed. Out of ignorance comes black and white certainty but the best odds are with those with in depth knowledge and a desire to add to and improve that knowledge.
Good on you Barry – although I suspect Jenny’s ratings will only rise from your attention but it’s still necessary to rebut her – there are people who do want to see the critics get critiqued.

Like

Leave a Reply (Markdown is enabled)