The consensus from Australian scientists in positions of authority on the issue of ‘river salinity’ and the ‘spread of dryland salinity’ appears to be crumbling.
As Mick Keogh wrote yesterday in The Australian Financial Review with respect to the issue of dryland salinity:
“Increasingly, researchers are concluding that many of the assumptions and much of the data used in generating this estimate [that 17 million hectares of farmland would be lost to salt] were wrong, or should not have been used. There are suggestions, for example, that some State salinity assessments used to calculate the national estimate overstate the current extent of salinity by factors of between three and seven times, let alone the projected future extent. Several of the state reports had no reliable data to base estimates on, and many made assumptions about future groundwater levels – a critical element in salinity assessments – that defy the laws of gravity and science, and are not supported by available data.
It would be easy to dismiss these criticisms if they were just coming from farmers who have an interest in downplaying salinity.But increasingly, the criticisms are coming from senior scientists and researchers employed by State and Commonwealth Governments, from University academics, and are contained in official reports and published research findings.”
Mick Keogh heads The Australian Farm Institute and published several papers in the institute’s journal last November (Farm Policy Journal, Vol 2, No. 4) by scientists and economists explaining that previous estimates were a gross exaggeration and that many of the policy solutions funded under the $1.4 billion Action Plan for Salinity and Water Quality are seriously flawed.
I have been questioning the figure of 17 million hectares since the Australian Dryland Salinity Assessment 2000 was first published*. I am on record in submissions to government inquiries and, for example, in Quadrant magazine in December 2004 explaining how myths are made:
“…[journalists at The Australian] have relied heavily on the government’s report “The National Land & Water Resources Audit’s Australian Dryland Salinity Assessment 2000” (NLWRA) for information regarding the spread of dryland salinity. The document warns that the area with a high potential to develop dryland salinity (from rising groundwater) will increase from 6 million hectares in 2000 to 17 million hectares in 2050, as reported by Hodge in the Australian on March 17, 2001.
The NLWRA has been widely cited and was used to help secure $1.4 billion in funding through the National Action Plan for Salinity and Water Quality. It is therefore worth considering its technical integrity.
Interestingly, the report does not distinguish between what might normally be considered irrigation salinity as opposed to dryland salinity. It determined that areas with groundwater within two metres of the surface are at high risk of dryland salinity. The forecast ground-water levels were “based on straight-line projection of recent trends in groundwater levels”.
Yet no data supports the notion that we currently have a situation of rising groundwater in the Murray – Darling Basin. Groundwater levels in the Murray, Murrumbidgee and Coleambally irrigation areas – the regions considered most at risk – have generally fallen during the past ten years.”
I have also questioned claims river salinity levels were rising, and would continue to rise, including in my IPA Backgrounder Myth and the Murray: Measuring the Real State of the River Environment.
John Quiggin has been scathing of my work on salinity and my daring to challenge “30 years of scientific research”. In April last year he suggested that the debate really comes down to a “a pure question of comparative credibility” and concluded I had none.
What a difference a year can make.
Now some CSIRO scientists are suggesting that their organisation may have got it wrong including John Passioura who wrote in a review paper titled From Propaganda to Practicalities – the progressive evolution of the salinity debate that, “Our only defence against the charge of charlatantism is that before deceiving others, we have taken great pains to deceive ourselves” (Australian Journal of Experimental Agriculture, Vol 45, pgs. 1503-1506).
John Passioura also commented:
“Remote sensing techniques, especially aerial electromagnetics coupled with good ground-truthing, were revealing great variation below ground in the occurrence of saline aquifers, both laterally and vertically. The methaphor of the ‘silent flood’, the widespread rapidly-rising uniformly-saline watertable that as going to take out millions of hectares of our most productive agricultural land, was therefore being questioned – not by the mass media, who embraced it with the macabre fascination that goes with gothic horror novels, but by experienced observers of landscapes and of hydrographs.”
Those who hate having to admit they might have been wrong, could now argue that Passioura and others are only referring to dryland salinity, not river salinity levels. That salt levels in the Murray could still be, just about to start rising again.
But come on, the boggie man with respect to reducing river salinity, has always been the argument that because of spreading dryland salinity, well, it would eventually find its way into the Murray and river salinity levels would start rising again.
This argument has now been exposed as just as hollow.
Let’s accept, it now appears that I got it right on both river salinity and dryland salinity! I feel vindicated. But I won’t hold my breath, waiting for an apology from John Quiggin or anybody else.
And I suggest Mick Keogh not hold his breath either, waiting for the ABC to correct the information at their websites.
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*It used to be easy to access the Salinity Assessment on the internet but now I just keep finding this ‘summary document’. Lucky I kept my hard copy!
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.