Oxford Martin School

Geoffrey West highlights the tension between growth and sustainability in 21^st century cities.

"I shall not today attempt to define ‘complexity' and perhaps I could never succeed in intelligibly doing so, but I know it when I see it.......!!"

Geoffrey West, an associate fellow at the Institute for Science, Innovation and Society, opened his talk in the 21^st Century School seminar series by defining ‘complexity science' using the U.S. Supreme Court's 1964 ‘definition' of pornography. Though tongue-in-cheek, it highlighted the difficulty in pinning down a topic as interdisciplinary, and well, complex, as the study of dynamic, adaptive systems.

His talk sought to answer the question, "How can the fundamental scaling laws of biological organisms help us understand social organisations such as cities and corporations?" Using his background in physics, West has developed a theoretical, quantitative and predictive framework that uses what he calls ‘stunningly simple' scaling laws and mechanisms to draw connections between systems at all levels, from particles to biological systems to social systems like cities, using the common denominator of networks.

Like biological networks, cities and other social networks have evolved to efficiently distribute energy and resources to all corners. Also in parallel to biological systems, cities go through many phases in the course of their development:

• Living/maintenance
• Growth
• Aging/death
• Evolution
• Sleep/repair
• Disease/cancer

According to West, there are systematic and fundamental laws underlying biological systems, pertaining to resource distribution and economies of scale. He presented a series of compelling examples drawing on cellular systems, neural networks and metabolic structures.

For example:                                                  

• The basal metabolic rate of any animal scales as the 3/4 power of body mass. This holds true for all animals, from single-celled organisms to the largest mammals.
• Heart rate scales as -1/4 power of body mass and metabolic rate sets the pace of life. Small animals live fast and die young (the rock stars of the animal world!). Across aerobic (oxygen-breathing) animals, the number of heartbeats in a lifetime is more or less a constant one billion.
• The relationship between the number and size of branches in a tree is analogous to the structure of blood vessels and the patterns of white matter in the cerebellum.

Having laid out these biological patterns, West set out to explore to what degree these can also be used to describe cities and corporate structures.

His findings show that while the infrastructure patterns of cities - roads, water lines and other resource distribution networks - tend to follow similar economies of scale to biological ones, the social systems of cities operate very differently.

In opposition to biological properties, social benefits and ills both increase by a power of 1.15 when the size of a city increases.

Doubling the size of a city results in a 15% increase in income, wealth and innovation per capita, as measured by number of patents. On the downside, crime, pollution and disease also increase by the same amount per capita in cities in the US, Europe and Asia. As 50% of the world's population now live in cities, heading towards 80% in 2050, West is interested in using this data to construct a general theory of cities and social organisations that is quantitative and predictive.

Biological systems differ from cities

in another key way - their growth is self-limited. When organisms no longer have access to the resources (food, water, energy) they need to survive, or those resources are distributed in a sub-optimal way, there are natural limits to growth. Human-designed systems, such as cities, however, can continue to grow unchecked until they run out of resources. When these resources eventually do run out, the consequences can be stagnation or even collapse.  According to West, the only way to head off this consequence is a major innovation or paradigm shift that enables a whole new growth curve.

West presented data from a variety of sources to demonstrate that in order to maintain continuous growth, there must be continuous major innovations or paradigm shifts at an accelerating rate, and the time between such innovations must systematically decrease. This presents a continuous tension between ‘innovation & wealth creation' and ‘economies of scale' to create a situation that is not sustainable.

These findings have dramatic implications for growth, development and in particular sustainability: innovation and wealth creation that fuel social systems, if left unchecked, potentially sow the seeds for their own breakdown. Theorists have estimated that society will reach this point of ‘singularity' within the next 20-30 years, and West is seeking to develop scenarios for avoiding what some say is an inevitable collapse.

West's talk sparked a provocative discussion about paradigm shifts, the nature of continuous growth, and ways in which society might avoid this point of singularity.

Join the discussion

• Are there other systems besides biology and cities that follow resource distribution laws?
• Can cities continue to grow without multiplying societal ills?
• What are the paradigm shifts that might bring us to sustainability?

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This blog was written by Susan Curran, Web and Publications Officer, at the Institute for Science, Innovation and Society.