"As recently as 1950, only 30% of the world's population was urbanised. Today, more than half live in urban centres. The developed world is now about 80% urban and this is expected to be true for the entire planet by around 2050, with some 2 billion people moving to cities, especially in China, India, southeast Asia and Africa."
This came from a commentary article, "A unified theory of urban living" in Nature, on the 21st of October, 2010. Of course, when we think of cities, we think of concentrations of people, culture, money and energy. Cities, interestingly, share many "universal features," claim authors Luis Bettencourt and Geoffrey West of the Santa Fe Institute and Los Alamos National Laboratory. "Doubling the population of any city requires only about an 85% increase in infrastructure, whether that be total road surface, length of electrical cables, water pipes or number of petrol stations." This is because of efficiency gains and higher quality services that aren't necessarily available in smaller places. We can view this in a neoclassical economic sense - economies of scale.
Paul today pointed me to the latest Radiolab, which is about Cities. In this episode, Bettencourt and West discuss the "economies" of living beings - as animals grow larger and more complex, the amount of energy it takes to maintain cells and live is actually less than it would be if you linearly scaled up the resources needed for smaller animals. In that sense, cities are kind of like animals...or are they? What we fail to realise, say Bettencourt and West, is that as cities grow, and people continue to move to cities, their access to resources increases, as do their wages, and interactions with people with different ideas. This can lead to, counterintuitively, more consumption of resources, although the efficiency with which those resources are consumed is higher than say a suburban area. At the same time, it is very rare that cities die. Now, there are of course, shrinking cities (like Youngstown, Cleveland, St. Louis and Detroit), as John Gallagher talks about in his book, Reimagining Detroit. But if we continue to move to cities, as is the trend noted by Bettencourt and West, will our use of resources decline?