Bernard Salt (“Global Cities Offer Us a Lesson on Population,” The Australian, December 1, 2016, p. 28) offers us a lesson in urban algebra, or comparative urban development. He compares various global cities with Melbourne and finds that Melbourne is almost a population desert.
New York contains 24 million residents; Manhattan Island has a population density of four times that of Melbourne and Paris, six times. Thus compared to America and European standards Australian cities have only a modest population density.
The sub-text here, no doubt is that Australia should become just as dense as America and European cities. All that however, ignores numerous factors, such as the ecological support base of such cities, such as water supply. New York has no such problem with water. As well, Manhattan and Paris can maintain the population levels that they support because they serve as concentrated business and cultural centres, supported by vast resources outside of their cities, constantly shipped and trucked in. The cities are highly artificial constructs.
With a Carrington EMP (electromagnetic pulse) event – thought to have a probability of 12 percent each year, these global cities would become vast tombs with a deathrate greater than 90 percent: http://collapse.news/2016-11-30-is-the-world-about-to-be-knocked-back-to-the-18th-century-some-experts-think-so.html.
Hence, the global cities are not sustainable, and neither is Melbourne. In the short term these human sardine tins may make an elite very rich, but I predict that within 100 years these centres will all come to the crumbling ruins, on the business-as-usual scenario, much as we see in the post-apocalyptic movies.