This is the third instalment of a series of environmentally-themed pieces submitted by doctoral researchers at the University of Michigan. This collaboration between the University of Michigan and University of Edinburgh began when a professor at the University of Michigan forwarded a link to the IANS blog, along with the opportunity to connect with its editors, to PhD students in Michigan's School of Natural Resources and Environment. After an initial meeting over Skype, two of Michigan's doctoral students were lucky enough to jet over to Edinburgh and participate in a lovely weekend workshop with IANS' staff. From there, the collaboration was born!
By Sara Meerow (Contributor)
In October 2012, Hurricane Sandy swept through New York and New Jersey leaving 73 dead and billions of dollars of devastation in its wake . Former Mayor Bloomberg called it “the worst natural disaster ever to hit New York City.” Years before the storm, New York City had an Office of Long-Term Planning and Sustainability and a comprehensive sustainability vision plan called PlaNYC. After Sandy, however, a new PlaNYC campaign for a “stronger, more resilient New York” was unveiled. This new plan is representative of a larger shift in popular and academic discourse on cities.
Urban areas around the world face numerous hazards, from climate change and increasingly devastating natural disasters, to economic instability and even terrorism. In the face of these challenges and uncertainties, many policymakers and academics have shifted their focus from becoming more sustainable to building resilience. There are many examples of this beyond New York City. For example, the Rockefeller Foundation announced a $100 million
100 Resilient Cities initiative, and the United Nations Office for Disaster Risk Reduction created the Making Cities Resilient campaign. These developments spurred Time Magazine to declare resilience the “environmental buzzword of 2013” .
Is this shift from sustainability to resilience meaningful or merely semantics?
I would argue that although the terms are often used almost interchangeably in cities, the theoretical foundations of the concepts are markedly different, and suggest some key distinctions.
The word sustainability can be traced back to the French term soutenir, meaning “to hold up or support”. In contrast, the modern dictionary definition of sustainable is “1) capable of being sustained; 2) of, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged” . In academic and public discourse, sustainability is often linked to the notion of sustainable development, which was defined in the Brundtland Report as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”  Definitions of sustainability differ, but it is generally seen as a normative, positive concept, and focuses on balancing economic, environmental, and social justice goals, whilst avoiding exceeding specific natural carrying capacities.
The term resilience comes from the Latin word resilio, which means to “jump back”. The modern definition is “1) the capability of a strained body to recover its size and shape after deformation caused especially by compressive stress; or 2) an ability to recover from or adjust easily to misfortune or change” . A similar definition of resilience has long been used in the psychology and engineering academic disciplines. This so-called “engineering” resilience is measured by the speed at which an individual or system rebounds from a shock .
However, in the more recent academic literature, a different conceptualization is often used. This definition is attributed to the work of ecologist C.S. Holling, which showed that because ecosystems are dynamic and complex, “bouncing back” to a previous equilibrium is unlikely . For these systems “ecological” resilience, defined as the ability to maintain key structures and functions in the face of a disturbance, is a more useful concept . The important distinction here is that ecological resilience does not suggest that a system will remain the same. In recent decades, Holling’s conceptualization of resilience has been widely applied and even led to the creation of the Resilience Alliance, an international, interdisciplinary research network devoted to “resilience thinking”.
While the intellectual origins and influences differ for urban sustainability and resilience, there are many similarities between the concepts. They both are somewhat ambiguous terms that have broad appeal, they both generally highlight the importance of the environment, and they are both usually seen as desirable goals. Nevertheless, there are other key differences between sustainability and resilience. First, it seems that social justice and equity are less emphasized in the resilience literature. Even more importantly, “resilience thinking” is based on a complex systems perspective that sees cities as in a constant state of flux. Thus, whereas sustainability attempts to predict and plan for the future of cities, resilience accepts uncertainty and focuses on building urban systems with the capacity to adapt to unexpected changes.
Designing and managing cities for ‘urban resilience’ may also conflict with traditional sustainability goals. For example, sustainability seeks to optimize eco-efficiency, yet research suggests that functional redundancy fosters resilience, and efforts to optimize efficiency can increase vulnerability . Thus, it may be necessary to balance efficiency and flexibility, in addition to the environment, economy, and social justice. As an illustration, this could mean that New York City maintains back-up sources of electricity generation in case of disruptions, even though doing so may require more resources in the short term. Conversely, building for resilience in the short-term may undermine long-term sustainability goals. For example, post-Hurricane Sandy sea gates were proposed for New York Harbor as a way to increase resilience to future storms. Yet these would arguably “lock the city into energetically, resource, and economically unsustainable long-term maintenance costs that also have serious ecological side effects.” 
If sustainability is defined broadly as a “persistence of all components of the biosphere, even those with no apparent benefit to humanity,”  and resilience as the ability for key functions and structures to persist when disturbed, the two concepts do not seem contradictory. For better or worse, in the manifold ways the terms are often used today, there are more similarities than differences. The key contribution of resilience theory is the recognition that for complex systems like cities, the inherent ability to adapt to change and disturbance is critical for long-term persistence in our current era of uncertainty and change.
But why not replace sustainability with resilience as some have argued? Both resilience and sustainability are useful concepts. Sustainability emphasizes the need to think about the long-term implications of current actions and trade-offs between environmental, economic, and especially social inter- and intra-generational justice. We can build walls around New York City to make it resilient in the short term, but if we don’t mitigate climate change the sea may well rise above them. And what about the people living outside those walls? These are crucial sustainability concerns. However, if eco-efficiency and balance are the primary sustainability goals, inevitable disruptions and future Hurricane Sandys will make long-term sustainability impossible for our cities. Thus, it is critical to focus on dynamic resilience, or the flexibility to adapt to the unanticipated disturbances and changes that are inherent to complex urban systems.
In my view, long-term sustainability is the overarching goal. System resilience is an essential feature of this vision, and broader “resilience thinking” should guide design and management efforts. This means developing urban infrastructure and institutions that expect the unexpected and are adaptable, flexible, and diverse, but that also support economic, environmental, and social justice goals. This will make our cities better places to live and better prepared to handle future crises. Fostering urban resilience and sustainability is a major challenge, but one that a growing number of scholars, organizations, and cities are taking up.
Sara Meerow is a PhD candidate in the School of Natural Resources and Environment at the University of Michigan. Her research focuses on the theoretical and empirical questions related to planning for urban resilience, climate adaptation in cities, and green infrastructure. She has a master’s degree in international development studies from the Department of Geography, Planning, and International Development Studies at the University of Amsterdam and a bachelor’s degree in political science and history from the University of Florida.
1. FEMA. Sandy Recovery Office. (2015). at <https://www.fema.gov/sandy-recovery-office>
2. Walsh, B. Adapt or Die: Why the Environmental Buzzword of 2013 Will Be Resilience. Time Mag. (2013). at <http://science.time.com/2013/01/08/adapt-or-die-why-the-environmental-buzzword-of-2013-will-be-resilience/#ixzz2JeE6rFwE>
3. Merriam Webster Online Dictionary. (2015). at <http://www.merriam-webster.com/>
4. Nations, U. Our Common Future. (1987).
5. Holling, C. S. in Eng. withn Ecol. Constraints (Schulze, P.) (The National Academies Press, 1996).
6. Holling, C. S. Resilience and Stability of Ecological Systems. Annu. Rev. Ecol. Syst. 4, 1–23 (1973).
7. Walker, B. & Salt, D. Resilience Thinking: Sustaining Ecosystems and People in a Changing World. 192 (Island Press, 2006). at <http://books.google.com/books/about/Resilience_Thinking.html?id=NFqFbXYbjLEC&pgis=1>
8. McPhearson, T. The Rise of Resilience: Linking Resilience and Sustainability in City Planning. Nat. Cities (2014). at <http://www.thenatureofcities.com/2014/06/08/the-rise-of-resilience-linking-resilience-and-sustainability-in-city-planning/>
9. Brown, B. J., Hanson, M. E., Liverman, D. M. & Merideth, R. W. Global sustainability: Toward definition. Environ. Manage. 11, 713–719 (1987).