So this article on islands of biodiversity in the Australian outback explains that at one point, Australia was covered with nothing but tropical rainforests, but then the continent was cut off from warm water currents when South America split from Antarctica and the new cold-water polar currents drove away the heat pump that once fed Australia abundant rain. Australia also underwent further desertification due to the fact that it is one of the oldest landmasses on the planet - nearly flat, and much of its mineral nutriment has been eroded away due to time. Also, rabbits are killing the continent, by chewing all the grass down to the roots and generally wreaking havoc on an already threatened ecosystem.
That got me to thinking - we can probably fix all three of those problems ourselves, with a little technological investment. And here's how!:
1. Water: This is the hardest challenge for greening Australia. We'd need some way to bring fresh water into the interior on a massive scale. One obvious way is a massive desalinization + pumps scheme to pull fresh water from the oceans and pump it into the Outback, eventually flooding parts of the land to fill-in dried up fossil seabeds that once existed in Australia's interior. It would be one of the largest construction projects mankind has ever attempted, and probably require some sort of automation/advanced robotics to build the structure in a reliable way, and fusion or some other cheap energy source to make it affordable.
Another possibly cheaper method would be a network of orbiting mirrors designed to heat the oceans around Australia and increase rainfall.
And thirdly, we could possibly make use of transpiration. Even though the Amazon should be a Savannah, it is not because the plants in the region help to hold moisture and act as a positive feedback loop. Perhaps if we started planting enough trees in Australia a similar effect might occur (it would also be a great carbon sink). Keeping them alive in Outback conditions though would require a lot of fancy underground irrigation systems, which makes this one somewhat similar to the first idea of flooding the interior with fresh water.
2. Rabbits: Rabbits do so well in Australia because there aren't any native predators, and introduced foxes prey on native marsupials more often than they target the rabbits. Stopping the rabbits remains one of the top priorities for a successful terraform scheme, because otherwise they would simply eat any possible new plant growth and undermine the work. So we need more native predators, to hopefully if not eliminate then control the numbers of rabbits. So why not re-introduce the tasmanian devil, and if possible resurrect the thylacine and introduce it as well? Both species lived on the continent in recent memory, and it would mean giving the marsupials a fighting chance over the introduced placentals.
3. The last one, dealing with the low nutrient count in the soil, is easy, and something we can do right now. Just dump fertilizer all over the place. To prevent algal blooms, we could wind-disperse it in areas far away from watersheds and over a wide areas, using blimps at an altitude.
I'm sure that there's some flaws in the plan (I'm not an expert yet on ecology, so yeah, this is mostly idle exploration than concrete idea), but the gist of it is that I'm sure we could if we were willing to invest in the technology turn Australia green again. What do you all think? Should we try to reverse desertification if its feasible? What about the ethics of it all?