Urban metabolism metrology: A new discipline elucidating the human condition in cities around the world

Presented by Rolf Halden


Understanding and managing the welfare of human populations is a priority of sustainability science. In the age of urbanization and the anthropocene, people are shaping their environment, and the environment in turn shapes the health of the people. Since 2008, the majority of humans live in cities. By 2050, two-thirds of a projected world population of 9.6 billion people will be city dwellers. Already today over half a billion people, or 8% of the current population, live in some 34 megacities of 10 million or more inhabitants.

Methods for the real-time analysis of the dynamic behavior, consumption, and health of urbanites are mostly still elusive, but the new scientific discipline of urban metabolism metrology  "interpreting a city as one comprehensive unit or organism that can be accessible qualitatively and quantitatively using stocks and flows analysis" promises much needed progress. Whereas urban metabolism metrology typically has been restricted to assessing urban budgets of materials, water, and energy, recent breakthroughs in analytical chemistry, computational methods, and big data access are now paving the way for a real-time flow of information essential to understanding and managing the human condition in cities around the world.

Vast opportunities in urban metabolism metrology reside in the analysis of the urban water cycle, as it relates to the chemical makeup of city effluent making its way in an underground sewer network to centralized treatment plants that can double as chemical observatories. Measurement of urban effluent composited for days and representative of hundreds of thousands of people makes possible the near real-time assessment of human wellbeing of urban populations in metropolises around the world. Analysis of raw urban water holds information on how many people congregate in a city at a given time, on their ethnicity, diet, behavior, prescription and illicit drug use, and on their overall health. The speaker will share data collected from over 160 U.S. cities and some 32 million Americans over the past 14 years to highlight advances of urban metabolism metrology, identify obstacles, and outline a path for developing public health dashboards that display in real-time the human condition in cities around the world.