Deforestation? Maybe not. As Tangledwood says, many people choose to live there because of the flora and fauna that surrounds them. Sydney is surrounded by bush, much of it extending right into and around the harbour itself. Large tracts of former government land are only now being released for public use - and not all for development. If you imagine clasped hands and the way the fingers interlock, that's how the settled areas and the bush look like from above. Much of the remaining bush has long been set aside as National Park areas, with very limited development allowed. Even if you could make the cultural leap to destroy such places to create fire-breaks, bush has the lucky habit of regenerating extremely quickly after fire, so such clearance could never be a once-for-all project. I've been amazed to see trees with trunks 95% burnt through, still sprouting new growth above the blackened stumps.

Ross