In virtually every species, the metabolic rate is equal to the mass of the animal raised to the 3/4 power [...] In metropolis after metropolis, the indicators of urban “metabolism” -like the per-capita consumption of gasoline or the surface area of roads or the total length of electrical cables- scaled to an exponent of (population)0.8
In The Living City, Giles Revell explains the results of applying the science of metabolism to the metropolis for Seed Magazine. The research conducted by Geoffrey West of the Santa Fe Institute is revealing amazing facts that could make any believers of the Gaia theory freak out. It turns out that cities behave like organisms, and this is not just a metaphor.
Although it may be common sense to urbanists, there are now figures to support the notion that bigger cities are more efficient than small ones. There goes your naive assumptions about a green future: forget about trying to retire to a rural community to save the planet, it is better to keep growing large cities as they consume fewer resources and consume less space per capita.
But metropolis are not only more efficient, they are also more productive as a result of the high density social interactions they are able to sustain. In this aspect, they reveal qualities that are superior to those of any living organism. As they increase in size they promote mechanisms to grow even faster, as long as resources remain available. However, history has demonstrated that when cities were approaching their limits, threatening their growth, a breakthrough innovation changed the rules and reinforced the growth cycle. Innovation being the result of those social interactions, of course. Jane Jacobs had already observed the importance of a busy sidewalk to promote communication between city dwellers.

[...] often analogize them to living organisms. The Santa Fe Institute even did a fascinating study on urban metabolism. It can be tricky, though, and misleading, this business of viewing cities as whole organic [...]
[...] I posted the living city back in January I had only read a journalistic interpretation from the original research. Thanks to [...]
[...] areas “spike” or thrive while others atrophy. Researchers at the Santa Fe Institute call this effect “urban metabolism.” (Where do you [...]
A published article on the research referenced in “The Living City” is by Luis M.A. Bettencourt, Jose Lobo, Dirk Helbing, Christian Kuhnert, and Geoffrey West, titled, “Growth, innovation, scaling, and the pace of life in cities.” It is published in the Proceedings of the National Academy of Sciences of the USA, available at: http://www.pnas.org/cgi/content/abstract/0610172104v1
Justin: SEED Magazine #11 (August 2007) pp 54-60. If you can’t find it in your magazine store, follow the links from his wikipedia entry to the Google Tech Talk.
Where can I find this article on the Living City? I searched it on seed magazine but didn’t get any results, and I’m very interested in reading more of it.