Phantom - I agree with most of what you say but am serious in my belief that polies of every party want to stay in power and lean whichever way the wind blows.
For the past 40 years all they have heard is carbon is evil/dams are evil/touching a forest is evil and sensible policies of the past (dams, forest maintenance, even population decisions) must be scrapped to save the world.
I believe issues can be addressed without the UN and without hurting the environment.
Rainfall Historical data shown below suggests that if anything Australia as a whole is getting more rain (note however a few lean years).
Governments react to squeaky wheels but you are correct that if the concern voters in urban areas spent as much time clamoring for water/food/fire security as social issues - some action would be taken.