The terrible destruction of the centre of Christchurch has been a tragedy for the citizens, not only the loss of life and property but also the loss of New Zealand's best planned city - a garden city on the plains with a clearly defined centre of cathedral and square. The contrast to Auckland could not be clearer. The European founders of Auckland actually had a plan, drawn by Felton Mathews in 1840, but they ripped it up almost immediately and the city has been growing where ever it wanted since then.
What does unify these two very different cities is the emptying out of the city centre. Even before the earthquakes the Christchurch CBD was being slowly abandoned, as urban development moved to the surrounding suburbs and region. Auckland's CBD lost its importance long ago, with only 13 per cent of the population working in the inner city.
This is not just a New Zealand problem, but a worldwide phenomenon. The causes are complex but increasing affluence, the massive proliferation of private transport infrastructure and a revolution in communication technology, have all contributed to the end of the traditional city centre. In Christchurch the physical destruction of the CBD has been compounded by the realisation that it will be extravagantly expensive to build and hard to insure any future construction in the CBD.
This flight from the CBD has often been presented as a terrible problem. But what if it was actually a tremendous opportunity? The world is in a desperate search for solutions to the looming global ecological disaster. The biggest culprit seems to be the city.
Cities consume three quarters of all planetary resources and generate more than three quarters of all waste. And they are growing -- more than half of humanity is already urban. In about a decade we will have about four billion people in urban areas, and in two decades, about five.