<p>On this episode of the Circular Metabolism Podcast, we were very excited to catch up with David Wachsmuth during the conference Brussels Ecosystem. David is the Canada Research Chair in Urban Governance at McGill University, where he is also an Assistant Professor in the School of Urban Planning and an Associate Member in the Department of Geography. He is an urban political economist whose research interests include city and regional governance, urban sustainability, housing policy, social theory, and the politics of urban public space. In 2012, David wrote an influential paper in the urban metabolism realm entitled: Three ecologies: Urban Metabolism and the Society-Nature Opposition. During this episode, we discuss how the urban metabolism metaphor was used over the years and it is a not necessarily a fleshed out method but a working metaphor to describe the relationships between urban areas and the environment. We take a closer look at how urban political ecology helps us to understand what happens when flows enter and exit cities and who benefits from them. For instance, in the case of water supply you take a river and follow it to understand who uses it and how. In the case of New York City, it historically covered its water needs through the Hudson river and in order to secure its supply it ended up buying all upstream lands and shutting off polluting industries. We can imagine that while this was possible some centuries ago, today with the globalisation of our supply chains this is unthinkable but puts forward a number of governance questions between cities and their hinterland which are not yet in place. In the future, urban metabolism will have to focus on the interfaces and boundaries between urban areas and their hinterlands as well as their transitions and transformations. It will have to integrate the quantitative part of industrial ecology and the political focus of urban political ecology. Enjoy this episode and don't forget to visit our website www.circularmetabolism.com to find all of our activities and productions. Also, make sure subscribe to your favourite app including Youtube, iTunes, Spotify and Stitcher to avoid missing any new episode. Finally, leave us a comment or a review to help us improve our podcast. Link to the paper "Three Ecologies: Urban Metabolism and the Society-Nature Opposition" Link to David's presentation at the Brussels Ecosystem conference Links to David Wachsmuth website - twitter</p>