As recent weeks clearly reveal a tipping point in Australia’s climate – with only 33 millimetres of rain in three months in Melbourne and none forecast for the next week – the revelation that the Murray-Darling Basin is drying out is not unexpected but shocking nonetheless.
‘“These weren’t mistakes”: “Dodgy” policies to blame for Murray Darling’s downfall’ that an Australian National University study demonstrating that vastly less water had been returned to the river system than claimed by the government. Maryanne also revealed large-scale water theft by the factory-scale irrigators in the basin’s upper reaches, who grow the water-intensive crops of rice, tobacco and cotton on a landmass whose rivers lack baseflow during below-average or even average rainfall. Water that in other continents creates baseflow is in Australia absorbed by dense proteoid root systems necessary to absorb scarce nutrients. In other Quaternary landmasses these nutrients have been enriched by orders of magnitude via mountain building and aeolian glacial tills. There, lower rooting densities and much smaller threshold rainfalls to activate runoff are not only possible but essential.
What they show as a requisite is that irrigators – politically powerful due to their unrivalled profits on Australia’s abundant land in wet years – to be absolutely forbidden from extracting purchased water. What has actually happened is that irrigators simply re-buy the water purchased by government, eliminating supposed additional flows. These flows are required to preserve ecosystems 13,000 times more ancient and comparably more precisely adapted that the 10,000-year-old (or younger) ecosystems of Europe, North America or New Zealand. Australian aquatic flora and fauna are adapted to flows three times more variable than those of Europe, North America, New Zealand, East Asia or South America, and lose out when flows are modified to fit farming practices tested in the fleetingly young Enriched World. In fact, as Mary E. White showed in Running Down: Water in a Changing Land, the entire Murray-Darling and Lake Eyre Basins – and indeed most of the higher Western Plateau – constitutes one ephemeral floodplain adapted to extremely irregular floods. This is utterly different not only from the fast-flowing streams in U-shaped valleys of most of the Enriched World, but even from the permanent slow-flowing streams of the Amazon Basin or the bayou country of the Southern United States, whose soils are relatively free of the enrichment found in most Quaternary landmasses outside Australia. In almost all of Australia, runoff occurs only ephemerally following abnormal rainfall, and when rivers do flow, they can cover the whole land area – as in the famous 1990 floods when Nyngan was completely evacuated.
Such environments are simply not designed for annual crops. In the natural state of the MDB, such crops would fail in the vast majority of years, and reservoirs six times those of Europe, North America or New Zealand are needed to maintain the same reliability of supply even ignoring higher evaporation.
Instead of “getting big”, Australia needs a plan for its farmers to get out – and get out as soon as possible. A “get out” plan would involve restoring the rivers of inland Australia to their naturally uniquely variable flows and specially adapted endemic species, and restoring farmland to native flora. This plan was proposed on a smaller scale for uneconomic less large farms two decades ago by Tyrone Thomas in his My Environmental Exposé, but contradicts a free market that locates agriculture where land is cheapest. However, where land is cheapest is precisely where farming does by far the greatest ecological harm. This is why a large-scale, long-term plan to take control of Australia’s rivers from Australian and foreign agribusinesses, and return our climatically vulnerable rainfed farmland to specially adapted native flora and fauna, is one of the most critical steps for reversing the ecological crisis. Benefits of mass revegetation will accrue not only to Australia but globally in terms of reduced greenhouse gas emissions and increased economic profitability on other continents incomparably better suited to agriculture.
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