More than that, the details of what has happened to the climate of southwestern Australia are simply not taught in schools in the Enriched or Tropical World, although the possess infinitely more relevance, utility and potential economic costs (farming and urban water supply) than the fate of ice caps lying in regions without cities, with no frost-free season to permit viable agriculture, and lacking Australia’s vast natural mineral resources.
Despite political (and scientific) dithering between 1980 and 2005 over what has caused a reduction of about five-sixths in runoff to Perth’s dams, the extremely insular scientific community has never been able to persuade even local people, that radical, uncompromising changes in planning in Australia are essential to reverse the decline.
In this context, it is revealing that Thomas Delworth and Fanrong Zeng of Nature have once and for all confirmed that the decline in rainfall over southwestern Australia is completely anthropogenic, and that natural cycles could never produce the observed rainfall declines. Delworth and Zeng demonstrate with good models that rainfalls are likely by 2090 to fall to between a quarter and three-tenths the virgin mean if Australian carbon emissions are not cut back. Such a value would leave Perth with a mean annual rainfall of around 300 millimetres – enough with hotter temperatures to qualify as a fully arid BWh climate under the Köppen system.
Delworth and Zeng are revealingly from Princeton Unversity in New Jersey rather than Australia’s depoliticised science bodies who should be urging the government to transfer 100 percent of private- and public-sector transport monies to a high-speed rail network and demolition of all (inherently unsustainable) freeways, and to ensure that road projects can be constitutionally challenged and wiped out: fuel inefficiency of single-occupant cars stands too low for any road to be viewed sustainable.
Whilst the idea of making road building illegal is radical, Australian ecology is so sensitive to climate change and land degradation compared to the exceptionally young land surfaces of Eurasia and most of the Americas. Australia is the thirteenth highest emitter in the world, yet its ecosystems have been adapted for tens of millions of years to similar (if wetter) climatic conditions as the continent’s pace of drift matched global cooling. This produced steady-state temperatures and soils throughout Australia. Contrariwise, Eurasia’s and the Americas’ soils have been completely transformed in merely two to four million years – from similar to Australia’s into soils averaging five times as much available phosphorus, with similar increases in critical nutrients sulfur, copper and zinc. Over a mere blip in geological time, Eurasia and the Americas change from ice-covered to uniquely hospitable for high-density agriculture. Thus, incomparably more rigid laws are required to achieve any kind of sustainability in Australia.
|Delworth and Zeng have confirmed that global warming is likely to ensure the Avon becomes a dry stream even during the former rainy season of southwestern Australia, as the rain-bearing fronts gradually disappear from the region.|