Saturday 6 October 2018

Why Coles’ drought levy is a con job

On the radio during September one would frequently see advertisements for a “drought levy” established by Coles on milk since the beginning of September, and for Coles aiding drought-stricken farmers.

With a record-dry year likely now from Melbourne into northern Victoria and possibly parts of New South Wales, the drought levy is understandable but in terms of environmental ethics – regardless of its good intentions to help farmers – it must be judged wrong.

The reality is that we – as Tim Flannery noted during the 2006 drought – are not seeing a drought at all, but a new climate. Scientific studies (Seidel et. al. 2007, Kidder et. al. 2004, Liu et. al. 2012) suggest the southern Hadley cell – which marks the limits of the outer tropical and subtropical arid belt – has shifted poleward by seven degrees of latitude since the 1960s. This is equivalent to 780 kilometres, or to Melbourne experiencing the climate of Moree or Walgett from before anthropogenic global warming, and can be seen in the intense anticyclonic circulation during the winter half-year below:
Winter half-year 850 millibar streamfunction over Australia since 2010 vis-à-vis before 1974 (courtesy of Earth System Research Laboratory’s NCEP NCAR R1)
These climatic changes have been uniform over the southern hemisphere, although the mapping at ESRL did not allow me to show a decent graph. Also, the intensity of the Hadley Cell in the southern hemisphere has increased steadily since the 1920s – and the increase since 2010 has been very large vis-à-vis the graph below:
Strength of Southern Hemisphere Hadley circulation, taken from J. Liu, M. Song, Y. Hu and X. Ren; ‘Changes in the strength and width of the Hadley Circulation since 1871’; Climates of the Past; vol. 8 (2012); pp. 1169–1175
In this context, the levies of Coles and Woolworths serve no other long-term purpose except to prop up dairy farmers who are already clearly unsustainable and likely to suffer even more as the Hadkey Cell spreads in the future. Models from the extremely hot Mesozoic (Chander et. al. 1992; Kidder et. al. 2004) suggest that the rapid poleward movement of winter storms away from the subtropics will continue with increasing global warming. This aridification must make the possibility of southern Australian farmers continuing to farm without causing mass extinctions of unique, ancient species remote. Indeed Hochman et.al. (2016) have suggested that poleward shifts of the Hadley Cell will inevitably stall and reverse technological grain crop yield increases in Australia during the 21st century.

There is, in my view, a much more sustainable alternative to propping up unsustainable land uses. Those concerned abut helping Australia’s farmers should aim not to prop them up, but to permit them make a radical transition via (at least partial and preferably complete) revegetation of their farms to ecotourism based land uses which mitigate rather than exacerbate man-made climate changes. A transition from unprofitable or erratically profitable farming to ecotourism would also reduce the risk of extinction for extremely ancient species that – unlike the rapidly speciating northern and western hemispheres – play irreplaceable roles in ecosystem function. For instance, lyrebirds play a critical role mitigating the intense fires (Nugent et. al., 2014) caused by scarcity of catabolic chalcophile elements in southern Australia (Orians and Milewski, 2007)

Whilst a transition from farming to ecotourism stands costly and difficult over the vast areas where the threats noted by Hochman et. al. are severe, certainly on a small scale conversion of struggling farmers to sustainable ecotourism – especially with currently underutilised public and private promotion of the unique characteristics of Australian ecosystems (Orians and Milewski, 2007; Flannery 1994; McMahon and Finlayson 1991) – would be a much more sustainable use of “relief” levies from sales of food in chain stores, and would mitigate the risks of future climate change that see drying possibly as extreme as 80 percent of virgin mean rainfalls by 2100.

References:

  • Chandler, Mark A., Rind, David and Ruedy, Reto; ‘Pangaean climate during the Early Jurassic: GCM simulations and the sedimentary record of paleoclimate’; Geological Society of America Bulletin, v. 104, pp. 543-559, 9 figs., 3 tables (May 1992)
  • Flannery, Tim; The Future Eaters: An Ecological History of the Australian Lands and People; ISBN 0730104222
  • Kidder, David L. and Worsley, Thomas R.; ‘Causes and consequences of extreme Permo-Triassic warming to globally equable climate and relation to the Permo-Triassic extinction and recovery’; Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 203 (2004); pp. 207-237
  • Hochman, Zvi; Gobbett, David L.; and Horan, Heidi; ‘Climate trends account for stalled wheat yields in Australia since 1990’; Global Change Biology (2017); published by CSIRO Agriculture and Food
  • J. Liu, M. Song, Y. Hu and X. Ren; ‘Changes in the strength and width of the Hadley Circulation since 1871’; Climates of the Past; vol. 8 (2012); pp. 1169–1175
  • McMahon, T.A. and Finlayson, B.L.; Global Runoff: Continental Comparisons of Annual Flows and Peak Discharges. ISBN 3-923381-27-1
  • Nugent, Daniel T.; Leonard, Steven W. J. and Clarke, Michael F.; ‘Interactions between the superb lyrebird (Menura novaehollandiae) and fire in south-eastern Australia’; Wildlife Research, vol. 41 (2014), pp. 203-211
  • Orians, Gordon H. and Milewski, Antoni V. (2007). ‘Ecology of Australia: the effects of nutrient-poor soils and intense fires’ Biological Reviews, 82 (3): pp. 393–423
  • Seidel, Dian J. Qiang Fu; Randel, William J. and Reichler, Thomas J.; ‘Widening of the tropical belt in a changing climate’; Nature Geoscience, vol. 1 (January 2008), pp. 21-24

No comments: