The natural systems has been so hugely changed by man, often for very good reasons. and this often cannot be undone nor is it always desirable to do so.
Man always has believed that he could mould the natural world to his own vision.
Show me one civilisation that has been successful? and endured to tell the story. Most are buried under sand and mud. Just what we are witnessing today in many parts.
Paul Sheehan's recent article is worth reading. Titled 'Floods steal precious topsoil - and future goes down drain' you can see the full article here http://www.smh.com.au/opinion/society-a ... 19jrq.html
The following is a short extract from that story.
We changed the landscape and so changed the weather..."
Australia reminds me of an injured person, gushing blood. Others gather around, concerned, yet nobody mentions the gushing blood, or appears to even notice.
Last night there was a telethon in support of people who have suffered from the floods in Queensland and there has been much discussion of the costs to the economy, the cost of recovery, the cost of lost coal exports. But there has been little discussion of the more fundamental issue. The rivers have been running brown. A lot of the lifeblood of this country has been gushing away in liquid mountains we don't even see.
A few sages warned that the worst thing that could happen to Australia after a decade of drought was sustained rain.
That is what happened across much of the eastern food basket. The sequence of extremes was not global warming, nor was it bad luck. This was an Australian-made disaster that was a long time coming.
The rivers have been dense with topsoil because so much of Queensland and NSW sat dry and vulnerable after years of so little rain.
I have heard some people comment on how pleased they are to see loads of new topsoil washed into their area by floods. But one district's gain is another's loss, and that loss is permanent. Australia's thin topsoil was the resource the European settlers exploited when they began to transform this country. What they didn't fully understand - and apparently it is going to take us 200 years to wake up - was that the landscape had already brilliantly evolved to sustain itself in a dry climate.
We came, we saw, we buggered. We've managed to fool ourselves that the soils have remained fertile by the illusion created by fertilisers which, while keeping crop yields high, have gradually exhausted the soil.
Some sense of the gravity of what blood rivers mean is provided in Dirt, the Erosion of Civilisations (2007), by David Montgomery, who teaches geomorphology at the University of Washington. He is a past recipient of a prestigious MacArthur Fellowship. His book's thesis is profound: ''Even if we take it for granted we know that good soil is not just dirt. When you dig into rich, fresh earth you can feel the life in it … While the world's population keeps growing, the amount of productive farmland began declining in the 1970s and the supply of cheap fossil fuels used to make synthetic fertilisers will run out later this century. How we address the twin problems of soil degradation and accelerated erosion will eventually determine the fate of modern civilisation.''
Dirt charts the history of soil depletion from ancient Greece to modern times. A depressing pattern sets in and never changes. When societies exhaust their topsoil, they collapse or are forced to move. The age of mechanisation merely sped up the process.
The history of Australians' ignorance in the management of water, and thus soil, can be found in The Water Dreamers (2009), by Dr Michael Cathcart, a lecturer at the University of Melbourne. He argues, compellingly, that Australia was settled amid ignorance of how the natural landscape conserved water, soil and vegetation. None of this would surprise anyone who paid attention to Professor Jared Diamond's visit to Australia a few years ago, or read his book, Collapse: How Societies Chose to Fail or Survive (2005), or listened to Australia's most famous science intellectual, Dr Tim Flannery.
But the most specifically prescient warning for Australia came from a most eccentric source, Peter Andrews, who predicted that after the drought eventually broke the rivers would run red and brown with the soil that had been sitting on the baked and denuded landscape.