It all started with a discussion in spring 2012 at an outdoor café in Munich with Niki Frantzeskaki, a brilliant young social scientist from DRIFT in Rotterdam. We both discussed how urban areas increasingly are exposed to unprecedented challenges due to globalization including climate change, and that the use of the concepts sustainability, resilience and transformation had skyrocketed both in urban policy and practice. But at the same time, we both agreed that the discussions were plagued by confusion and vagueness on what the concepts meant. For example, it was quite clear that in the urban planning community there was a lot of frustration and confusion about the concept of urban resilience. I had many discussions with Cathy Wilkinson, a former planner from Melbourne who at the time was working on a PhD-thesis at Stockholm Resilience Centre on urban planning and complex systems theory. According to Cathy, the conventional narrative around resilience as illustrated by the system shifting between stability domains did not communicate well with the planners. Something different was needed. 

The discussion around this carried on with Dr. Erik Andersson at Stockholm Resilience Centre and Dr. Timon McPhearson from the Urban Systems Lab at The New School and intensified during the planning for the Sustainable Development Goals (SDGs) in 2014 and 2015 and particularly the discussions around the specific SDG 11 on cities “Make cities and human settlements inclusive, safe, resilient and sustainable”. Although resilience and sustainability in the urban context here is viewed as distinct and meaning different things (far from always being the case) the impression was that the two concepts tend to most often be positively correlated. In this way, policies for a resilient city risked being interpreted as policies for a sustainable one. We viewed this is a fallacy and started to prepare a response. We had at the time numerous discussions with Carl Folke and Per Olsson at Stockholm Resilience Centre building on the long legacy of deep intellectual probing of the concepts of sustainability, resilience and transformations at SRC. 

In particular, we thought, it was important to highlight that if interpreted in a narrow sense, urban resilience and urban sustainability may be at odds of each other. Urban sustainability often aims to avoid inefficiencies, for example through optimisation of existing infrastructures and adapting institutions. Yet, designing for maximised efficiencies e.g. in transportation and energy systems, ignores a key characteristic of resilient systems: redundancy. For example, maximizing efficiency in energy delivery systems result in vulnerability to e.g. natural disasters when there is a lack of parallel or redundant back-up systems. Sustainability goals and resilience goals, if not examined carefully, can therefore be at odds with one another. 

This insight of the great need for clarifications became even more pronounced with the publication of the New Urban Agenda, adopted at the Habitat III conference in Quito 2016. In discussions leading up to the meeting in Quito, Prof Takeuchi from University of Tokyo made valuable contributions on the need for bring all three concepts, resilience, sustainability and transformations together. I started to draft the figure that later became the central piece in the paper (see animated gif). 

Instead of having multiple stable states, we describe urban systems as having multiple possible development pathways. Resilience is understood as the capacity to adhere to, or simply, to strengthen a specific pathway. We visualize this as a “tunnel” surrounding a pathway, where the width represents the tolerance of the system to external disturbances, experimentation, mistakes and errors, i.e. capacity to deal with uncertainties, continue to develop while maintaining functions and stay on the same trajectory. The width of the tunnel can be managed, by applying resilience thinking and either widened to make sure a system stays on a desirable pathway and allow for necessary transformations.

We believe that the more stringent definitions and visualizations of the three concepts we finally present in the paper will be very helpful for their more practical applications in view of all the urgent global challenges cities and regions face in the next three to four decades. For example, at the end of our paper we ask a number of challenging questions where a deeper understanding of resilience, sustainability and transformation will be crucial and helpful: 

Does urbanization result in diversification or simplification of the intertwined system of people and planet and how does it affect global sustainability? Is the increasing connectivity of cities becoming a force on its own in governing human affairs and in shaping the biosphere and to what extent is over-connectivity causing new types of vulnerabilities and influencing both sustainability and resilience? What is the role of cities in shifting global development towards more attractive trajectories, to become a stabilizing, resilience building force of the Anthropocene?