Cities that lose heart, are timid, or feel unwelcoming, are places that will gradually lose relevance. In that context, I'm worried about Sydney. It is still brash but it certainly is not bold.

This when a new urban age has been proclaimed and when more than half the world's population live in cities. Foreign Policy magazine makes the point that in the 21st century, cities, rather than states, are becoming the islands of governance on which the future world order will be built. Alongside the global giants of London, New York and Hong Kong, is an emerging new category of mega city - city-states along the Persian Gulf and the super-populous cities of Mumbai or Shanghai. By 2025 China is expected to have 15 super cities with an average population of 25 million, where Europe will have none.

Talk of mega cities is the sort of thing that drives Dick Smith to produce Hobbesian-style nightmares that are aired on your ABC. He is part of the ''shrink Australia'' crowd. We can, if we choose, sit at about 22 million, and say to the rest of Asia, ''sorry, we're full.'' When they stop laughing in Shanghai and Manila and Jakarta, we'll start to slip into irrelevance, just like Europe.

To my mind, the ''shrink Australia crowd'' is suffering from an imagination deficit. They cannot, or will not, see that well designed cities can be our salvation. If we get over our hang-up about density, and start thinking and investing in innovative urban design, then the future starts to take on a whole different aspect.