Advancing City Sustainability via Its Systems of Flows: The Urban Metabolism of Birmingham and Its Hinterland

Cities are dependent on their hinterlands for their function and survival. They provide resources such as people, materials, water, food and energy, as well as areas for waste disposal. Over the last 50 years, commerce and trade has become increasingly global with resources sourced from further afield often due to cheap labour costs, better transportation and a plentiful supply of energy and raw materials. However, the use and transportation of resources is becoming increasingly unsustainable as the global population increases, raw materials become increasing scarce, and energy costs rise. This paper builds on research undertaken in the Liveable Cities Programme on the resource flows of Birmingham, UK. It investigates how people, material, and food flows interact within regional, national, and international hinterlands through road and rail transportation and assesses their sustainability across all three pillars (economic, social, and environmental). The type and weight of goods is highlighted together with their costs and energy used. For a city to move with greatest effect towards sustainability it needs to: (i) source as much as it can locally, to minimise transportation and energy costs; (ii) adopt such principles as the “circular economy”; and (iii) provide clean and efficient means to move people, especially public transportation.