I believe every country in the world should follow the Chinese one child policy and married couples should be encouraged to adopt children from orphanages instead of having children themselves. We should also knock down lots of old houses that are completely run down (i know Australia has loads of them) and replace them with multistory high apartments. This will contain lots of pepole in smaller spaces. Each apartment only needs to have two or three bedrooms since couples will only be having one child. We should also build these in the countryside and provide those areas with enough technology to function while ensuring not too much country land is used up so that we still have enough produce. Maybe we could also try expanding to African countries. They could use the population and technology which in the long run, will eradicate poverty ofcourse that will take about 200 years.