
I've often thought the most 'sustainable' thing you can do in WA is leave. There was a reason the population remained at about 6000 for 45,000 years. Since that ain't gonna happen, you need to do what you can to ensure the least amount of effort is expended to provide the most amount of benefit. One trip to bring goods to where they are needed for lots of people is more efficient than ten trips to ten people. That's why towns and cities developed in the first place.
I'm getting the feeling you live in the bush and think living in cities is madness? Well 1 million other people don't seem to mind it, as does 80% of the world. There's too much arable land out there being swallowed up by suburbia to the point now where we have to import more fresh produce than we produce. Crazy, but it's more profitable to grow houses than to grow food.
So, before I detail why I think low density sprawl is an unsustainable thing to do, I would like to hear your explanation as to why it might be OK.