Sustainable cities as organisms, a circular thermodynamics perspective
More than 50% of us now live in cities while world population growth and urbanization continues unabated. There is an urgent need for policies that can address both the challenges and opportunities for sustainable development in urban settings. Within the past two decades, the idea of cities as fractal structures resulting from social and economic processes led to a transition in thinking of cities as machines to cities as organisms. Independently, the concept of ‘sustainable cities’ had emerged earlier, with many successful implementations already underway. I propose to define a sustainable city as one able to feed and power itself as much as possible using land and energy efficiently with the least environmental pollution and impact on climate change, minimizing wastes and recycling and reconverting wastes into resources. Coherent fractal space-time structures are the key to a circular thermodynamics of organisms and sustainable systems that achieves the state of minimum entropy production and dissipation that Ilya Prigogine had proposed as a conjecture. In this article, I explain how the principles of circular thermodynamics can be applied to sustainable cities.