Thursday, 23 July 2009

Coorong salinisation shows Megalogenis is right

In today’s Age, there is a despairing article showing how very low flows in the Murray River is already changing the former estuary in the Coorong, making it five times as salty as the sea and eliminating its outlet to the ocean completely.

Whilst a ten-degree poleward expansion since 1975 of the Hadley circulation is clearly responsible for the record low flows in the Murray River – and as I said earlier could have been predicted without the sophisticated computer models now used by the CSIRO (all we really needed were paleoclimatic indicators from the Tertiary), that does not mean we should do something to prevent the Coorong from becoming a sterile wasteland.

I have always thought George Megalogenis right in saying it would not be a bad thing if Australia were a net importer of food because of the very low runoff ratios and consequent fragility of Australian hydrological systems, as shown by the following data based upon Tom McMahon’s brilliant book Global Runoff: Continental Comparisons of Annual Flows and Peak Discharges.

Comparative Köppen BS, Cfa, Cfb, and Cs climate runoffs in Australia and other developed nations
Mean annual rainfall
Typical runoff in Australia
Typical runoff in Europe, the Americas and New Zealand
Ratio of Australian runoff
Ratio of Australian evapotranspiration (rainfall minus runoff)
280 mm
2 mm
30 mm
380 mm
10 mm
90 mm
650 mm
30 mm
180 mm
1,150 mm
250 mm
750 mm
Recent record low flows in the Murray suggest that under man-made global warming the extreme age of Australia’s soils, which caused the original difference through requiring much higher floral rooting densities to absorb minimal phosphate that is provided in highly bioavailable forms in the very young soils of Eurasia, the Americas and New Zealand, may have an exaggerated effect.

If this is correct, Megalogenis’ September 2007 Australian article (mentioned above) is a blanket understatement. Runoffs from the last few years represent expected conditions under present atmospheric CO2 levels. This means levels of runoff ten percent or less those observed from 1885 to 1996, and worse still the runoff includes that runoff which in the absence of irrigation would evaporate rather than reach the Coorong.

Hence, Australia cannot afford to allow any water that might reach the Coorong to be lost in the long term, so that saving the Coorong really does mean not irrigation in the Murray-Darling basin whatsoever. Since paleoclimate records give no evidence that at projected future carbon dioxide levels there will be any winter rain for grain crops, Australia’s only option is to import its food supply.

Most Australians probably think it unfair that Australia should have to import its food supply with so much farmland and would fear the extra cost of transport will add to global warming. The realities are instead:
  1. Australia’s farmland is all very low-yielding due to extremely old soils
  2. Australia’s abundance of land and energy deposits provides very low living costs
  3. Australia’s abundant farmland makes farmers on land abroad farmed sustainably for thousands of years economically unviable without subsidies
  4. Large-scale farmland revegetation in the Murray-Darling Basin provides opportunities for phasing out farm subsidies in most Eurasian and North American nations without the risk of these nations becoming wholly dependent on tourism and technology
  5. Those services are merely, as even Hans Hoppe exceedingly sensibly says, the services they are at a least disadvantage in producing rather than those they have special advantages producing.
  6. Australia’s abundant land gives its residents a privilege in low living costs that present climate change and greenhouse emissions show unsustainable. It similarly gives its farmers a privilege in cheap land – and low prices naturally cause poor maintenance and inefficiency, as was observed with grazing in western Queensland as early as 1957.
  7. If food prices in Australia increase, it will be merely to normal global levels and not to something unusually expensive, especially if one factors in the ecological cost of living in a fragile environment.
  8. Farming without lavish subsidies will offer hope that a culture where children are not a liability can develop and dangerously low fertility disappear abroad. This is because unsubsidised farmers have an incentive to hand their property down in a way not present with tenant or long-term mortgage-payers in cities.
  9. The cost of protecting Australia under an “Australian Treaty” might not be as high as Europe’s and East Asia’s lavish farm subsidies, especially if returns from high-cost tourism in which a visit to Australia is seen as the most special of experiences (in environmental terms, for the European or North American or New Zealander, it is a step into the Earth’s history).

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