We are only just coming to terms with the magnitude of our ignorance about this place, and the magnitude of the changes we have made. Much of what we think is "natural", such as our entire river system, is, in fact, unnatural, the product of massive human intervention, of trying to turn Australia into Europe. We've failed. What took 2 million years to evolve took 200 years to bugger. Even environmentalists are on a steep learning curve, with many locked into dogmas that will do more harm than good.