What is the role of the city in sustainable growth in the twenty-first century?
This question has been central to our work since the Institute’s founding ten years ago. Now, as Penn IUR begins its second decade, the question is even more pressing. With 4.3 births per second occurring worldwide—more than half in cities—“understanding cities, understanding the world” is increasingly to the point.
We asked a number of urban experts to reflect with us on the question of the city’s role in the twenty-first century. Their answers are provocative and will help further Penn IUR's mission of advancing impactful urban-focused research that informs public policy.
Eugenie Birch | It's Time for a City-focused Sustainable Development Goal!
Raphael Bostic | City Will Be a Star in the Story of Sustainable Growth
Charles Branas | Municipal "Health Smart" Planning and Urban Development Must Lead
Tom Daniels | Cities Can Blaze a Trail for Global Progress
David Hsu | Some Cities Will Help, Some Cities Will Hurt
Mark Alan Hughes | Can the Critical Condition of Density Survive the Twenty-first Century?
Abha Joshi-Ghani | Unprecedented Demographic Shift Demands a New Frontier
Alan Mabin | Overcoming Underlying Conflict: A Prerequisite
Randall Mason | Inheritance and Innovation Must be Fused
Gary W. McDonogh | Learning From Mistakes, Misunderstandings, and Questions
Rolf Pendall | Answers Will Be Found in Complexity
Brent D. Ryan | Our Best Chance
Saskia Sassen | An Emergent Urban Geopolitics
Thomas J. Surgue | "Comeback" Is Not Enough
Catherine Tumber | One Size Does Not Fit All
Susan Wachter | Inclusive Economic Growth Holds the Key
Richard Weller | From Wasteful Machines to Eco-logistical Metabolism
Laura Wolf-Powers | To Make the World We Want
Eugénie Birch, Lawrence C. Nussdorf Professor of Urban Research and Education, Chair of the Graduate Group in City Planning, City & Regional Planning, and Co-Director, Penn Institute for Urban Research, University of Pennsylvania
Next year, the United Nations will issue Sustainable Development Goals (SDGs) to replace the important Millennium Development Goals (MDGs) that expire in 2015. These goals are intended to respond to global trends with an aspirational and action-oriented agenda to inspire public and private decision-makers to pursue policies and programs that will yield an equitable, economically productive and environmentally responsible world. The last time around, the MDG crafters practically ignored a key trend: urbanization. Almost as an afterthought, they included within a broad environmental directive the target of improving the lives of 100 million slum dwellers by 2020. While the nations met the target well in advance of the deadline, it was a poor marker for progress. The number was not only lacking ambition—the number of slum dwellers actually increased by one third during the period—but it was too narrow, missing a holistic view of cities and their growing needs. Cities house half the world’s population and produce three quarters of the global GDP, yet they shelter nearly a billion in poverty-stricken informal settlements lacking public goods (e.g. clean water, basic sanitation, transportation, education).
Neglect by those who created the MDGs is astonishing. It should not be repeated in the crafting of the SDGs, though signs are present that it may be. So today’s challenge is: How can the UN be persuaded to direct specific attention to urban places? With today’s global urban population of 3.5 billion expected to nearly double, and an anticipated 2 billion anticipated to live in slums, place matters. The spatial dimensions of urbanization are forces to be identified, harnessed, and directed. An SDG that recognizes this fact with an explicit geographic focus on cities is in order. A simple and clearly articulated sentence would do the job: "Achieve well-planned, sustainable, productive, and inclusive cities and human settlements." Associate it with timely, measurable targets, clustered around such key themes as improved spatial configuration (e.g. reduce sprawl and peri-urban development), improved living conditions (e.g. upgrade slums and accommodate increased population with well-planned, fully serviced urban extensions) and improved enabling urban policies (e.g. widen the adoption of national urban policy). UN Secretary-General Ban Ki-moon has said: “Cities are where the battle for sustainable urban development will be won or lost.” I hope you will agree.
Raphael Bostic, Judith and John Bedrosian Chair in Governance and the Public Enterprise and Director, Bedrosian Center on Governance, Sol Price School of Public Policy, University of Southern California
At the end of the twentieth century more people were living in cities than at any time in human history. While a reflection of the tremendous productive power and capacity of cities, this increased concentration of people and production also comes with negative effects that call into question the sustainability of current development and growth trends. This places the city at the center of all efforts to establish a model of sustainable growth that extends well into the twenty-first century and beyond. The only way that we will make significant headway on all of the key sustainability issues we currently face is to find solutions that work in cities. Thus, the most important innovations that “solve” sustainability challenges will be those that reduce the urban contributions to problems of power generation, water use, food production, pollution, and climate change. These are the ones that will have the scale able to measurably ease sustainability pressures and put us on a path to stable growth that also preserves the planet. We all must work hard to find these innovations, however, as their discovery and widespread adoption is not assured. Indeed, sustainable growth is not a foregone conclusion for the next century. Put another way, the city will clearly have a starring role in the story of sustainable growth in the twenty-first century. The only question is whether that role will be as hero or villain.
Charles Branas, Professor of Epidemiology, Biostatistics and Epidemiology, University of Pennsylvania
The twenty-first-century city is the greatest opportunity for sustainable commerce, economic prosperity, and intellectual growth that humankind has ever known. But what of human health? What of the enormous opportunities our rapidly changing cities now pose for making people healthier and, by extension, happier and more productive than ever? Electric power grids, water treatment plants, building codes, and roadway redesign did more to enhance the health of twentieth-century city residents than many (maybe any) other programs, including medical care. If they have not already done so, twenty-first-century cities should make “health smart” planning and urban development a leading municipal pursuit. Physicians and police chiefs, sanitarians and city planners should all be on the same team, working to change the very structures of their cities and sustainably transforming health for large numbers of people over multiple generations. Somewhere along the way we forgot the power of these seemingly strange connections. Perhaps it’s time to rekindle them and put health prominently back into the equation for sustainable growth in our cities.
Tom Daniels, Professor of City & Regional Planning; Director of the Certificate in Land Preservation Program, City & Regional Planning, University of Pennsylvania
Sustainable growth is economically robust, environmentally healthy, and socially equitable. Since 2007, a majority of people have been living in cities for the first time in recorded history. And this trend is expected to increase through the twenty-first century. This means that cities must be the leaders for producing global progress on economic expansion, reducing pollution and greenhouse gas emissions, and promoting social harmony.
Cities are the driving forces of metropolitan regions, which have replaced countries as the unit of global competition. Studies have shown that the stronger the economy of the central city, the more resilient is the economy of the metro region.
Climate change is the world’s largest long-term threat. The main sources of air pollution and greenhouse gases that contribute to climate change come from burning carbon-based fossil fuels. Cities are more energy-efficient than suburbs or rural areas because urban dwellers often have the option to walk, bicycle, or take mass transit and they live in smaller homes and apartments that use less energy for heating and cooling.
Water quality and adequate water supplies are essential for public health and economic growth. Improved sanitation systems, especially in the developing world cities, water conservation, the protection of urban water supplies, and green infrastructure to help manage stormwater will be paramount.
Cities must be socially sustainable by providing quality affordable housing to accommodate growing populations. In developing countries, where most of the population growth will occur, squatter settlements and urban slums are wholly inadequate. In any city, green spaces are needed to promote public interaction and healthy lifestyles. Environmental justice should guide the location of public amenities and necessary but unpleasant infrastructure, such as electrical substations. Finally, arts and entertainment bring people together in cities.
David Hsu, Assistant Professor, City & Regional Planning, University of Pennsylvania
I am skeptical of the idea that all cities will be sustainable. Cities seem to be potential centers for sustainability, because they are correlated in global development statistics with higher economic growth, rising levels of education, and falling birth rates, and because activist mayors are ahead of dysfunctional national politics. In the next century, however, the challenge will be to reconcile local efforts at sustainability with the fact that the global environment is still getting worse and not better.
Higher density, urban living has many advantages, but density arguments ignore the fact that in absolute numbers, our global consumption and waste production is still growing rapidly. New climate-driven risks will affect every city, ranging from immediate events like drought and hurricanes; to slow but inexorable problems like sea level rise; as well as water crisis, energy poverty, inequality, the persistent growth of bio-accumulative and toxic chemicals, and mass extinction of species.
The transfer of goods, people, and pollution between cities is a critical part of the story. Resource consumption in a financial capital like New York extends worldwide, and the majority of urban growth will occur in new small and medium cities that exist as small towns today. Reducing air pollution in one place (like Pittsburgh) may be a temporary or even false victory if people move to places (like Phoenix) that are water-limited or if heavy industry moves to places (like China) that verge on environmental catastrophe. Climate-driven refugee migration may further destabilize existing countries.
The necessary role for cities is therefore, somehow, to help accommodate the cumulative impact of the population of nine billion people—expected in 2075—and to get us below the finite capacity of the planet’s resources on an ongoing basis. Some cities will help, some cities will hurt, and we need to know the difference.
Mark Alan Hughes, Professor of Practice, School of Design, University of Pennsylvania
Two of the most important claims made for cities are really statements about density: that it fosters, first, a resilient use of resources and, second, a productive setting for innovation. The first is a good-enough definition of "sustainable" and the second of "growth." If we maintain the assumption above that density is a defining quality of "cities," we've started a fairly comprehensive response to the prompt about the "role of cities in sustainable growth," which is that density generates resilience and innovation.
But can the critical condition of density survive the twenty-first century? The most important role cities play in the coming decades may well be the stewardship of the civic conditions that make density possible, which in turn is necessary to sustainable growth capable of meeting human needs on a challenged planet.
The 2013 film "Her" portrays a not-too-future Los Angeles in which people move around on elevated trains, live in even more elevated apartments, and work in clusters of office stations that have no compelling reason to be in the same place. It's a brilliant film that uses our relationship with technology to explore the limitations that make us human.
The film also requires density as a plot device for its characters to develop: they seem to live and work in the same towers, which allows their interaction at key moments. And the observation of public life in plazas and on beaches is the means by which humanness is quickly taught to the non-human character in the story.
But in this beautifully realized film world, there is no crowding, no discord, no inequality, no scarcity. Nor is there any accounting for why. How a city can create, contain, and continue such idealized "warmth of density" is not just a challenge to cities—it appears to be the necessary condition for everything else we expect and require cities to do for us in this century. It's a challenge that probably requires looking backward as well as forward.
Abha Joshi-Ghani, Director for Knowledge Exchange and Learning (WBIKL), The World Bank
There is no doubt that cities will play an important role in sustainability in the twenty-first century. Increasingly, cities are where a majority of the world’s population will live and, therefore, cities are central to sustainability. How they are designed, planned, and governed is key to how resource-efficient and sustainable they can be.
An unprecedented demographic shift is taking place. We all know the statistics: nearly three billion people are expected to move to cities by the year 2030, with 90 percent of this growth occurring in developing countries. This urban transformation presents tremendous challenges, with which we are all familiar: congestion, air pollution, social divisions, crime, the breakdown of public services and infrastructure—and the slums that one-third of the world’s urban resident’s call home.
But cities have the potential to provide solutions to these challenges. Cities can embrace sustainability by purposefully following the path of low-carbon growth. They can choose between sprawl, individual automotive-driven growth, or energy efficient, compact, dense design with integrated public transport, housing, and land-use policies. Most rapidly growing cities today need to invest in infrastructure to meet the needs of their burgeoning populations for services such as water and sanitation, transport, and housing. Investments in urban infrastructure can have consequences for 50 to as much as 200 years. The right investments and policy decisions today can lock in systemic benefits for generations to come, while poor choices may forever constrain a city’s competitiveness, livability, and social and environmental health. Low carbon and environmentally sustainable cities are the new frontier of development. While national policies and frameworks are important, eventually cities are where the action must take place. They can learn from the successful examples of others, gain insights, adapt, and innovate for successful, inclusive, and sustainable urbanization. With the right policies and vision, cities will be the key drivers of sustainability in the twenty-first century.
Alan Mabin, Research Fellow, Centre for the Advancement of Scholarship, University of Pretoria
Cities are our main sites of creativity, productivity, and life improvement, and these roles are intensifying in the twenty-first century. Only in cities can we anticipate new forms of economic growth and development that will allow resources and people to combine to dissipate the problems of twentieth-century growth models. But cities have not always generated consensus, peace, and happiness. Underlying conflict are lines of fracture that can threaten the endurance of cities and of their wider societies, as present tragedies in Timbuktu, Damascus, and Goma show. In the twenty-first century, cities must overcome grinding inequalities to achieve something vastly more sustainable.
Randall Mason, Chair/Associate Professor, Graduate Program in Historic Preservation, School of Design, University of Pennsylvania
Answers to the question about sustainable growth in the twenty-first century shouldn’t be confined to “what’s new.” Giving some critical attention to twentieth-century (and earlier) notions of balancing development and conservation holds as much promise of yielding solutions that can satisfy the technological, economic, political, and cultural challenges faced by future cities.
While “sustainability” has become a powerful concept to describe and model good urbanism and development, most notions of sustainable growth or design underplay the importance of inherited patterns, processes, and practices. Our sources for sustainable development and balanced urbanism come as much from the past as from unabashedly new ideas. Sustainability will thrive by cultivating and embracing the notion of urbanism as an inheritance—and its analog in practice, stewardship of what’s inherited.
Acknowledging the roots of sustainable growth does not mean an unthinking turn to the past, or merely looking backward. The questions are: How can cultures of inheritance and innovation be fused? How can “conservation” be accepted as a sustainable growth paradigm?
Such questions put me in mind of Lewis Mumford. The insights of City in History and Culture of Cities—masterfully synthetic and penetrating works of historical scholarship—were situated and deployed by Mumford as contemporary criticism. His was a “heritage” approach—history of scholarly heft made useful for contemporary purposes. Mumford’s work about the past was a generator and seedbed for ideas about his very contemporary engagements as a critic and theorist: truly metropolitan urbanism, reasoned acceptance of modern innovation, critical reception of modern design. Do these challenges sound familiar? Sounds like what twenty-first century cities need to strengthen and extend the sustainability paradigm.
Gary W. McDonogh, Professor, Growth and Structure of Cities, and Coordinator, Mellon Mays Undergraduate Fellowships, Bryn Mawr College
The challenge of sustainability in global cities is no longer simply one of models, planning, or slogans (we have more than enough!); this is a time for citizens and dialogue. Top-down regulations and abstract debates have had their place, from expanding mass transport to rethinking land uses and green facilities to ongoing struggles to define creative urban models for the future, but now planners, politicians, and academics must engage the complexities of real people who embody the contradictions of sustainable cities. People who conserve in some areas of their lives but consume precariously and unthinkingly in others. People who grapple every day with social exclusions and differential abilities, identities, and access yet who lack clear models for environmental citizenship or even time for reflection. Sustainable visions need to incorporate those who value their senses of place, of terroir, but who express these values not through theories but rather through concrete perceptions of loss and risk, sometimes at the hands of far-too-visible competitors and other times because of more distant and shadowy forces of power that threaten cherished lifeways. Sustainable visions must deal with people who respect sustainability in the abstract but treat it as inconvenient, or at least easily postponed until some undefined tomorrow.
If sustainability—social, economic and ecological—is the paradigm for twenty-first century urbanism, learning from the grassroots must become part of inquiry and of answers. This includes learning from the mistakes, misunderstandings, questions, and diverse practices of real people, and means dealing inclusively with varied peoples who are living in and recreating burgeoning metropoles, small cities, and even suburban sprawl. It means engaging in creative give-and-take, in translations as well as appreciations beyond traditional expertise. Shared, more sustainable urban futures must be built together.
Rolf Pendall, Director, Metropolitan Housing and Communities Policy Center, The Urban Institute
Sustainable growth needs cities because cities are the incubators of innovation for social equity—a linchpin of true sustainability. Cities allow the evolution of complex ecologies of organizations and governments that connect low-income people with opportunity and reduce their exposure to precarious situations. Such institutional networks will be increasingly important as the United States and the world face two huge challenges—climate change and demographic transition. Climate change will inevitably dislocate, dispossess, and harm low-income people wherever they live; when they live in cities, however, they have access to and participate in institutions that protect them, help them recover, and engage them in the reconstruction of their communities. Demographic transition entails the addition of 100 million people in the United States and 3.5 billion people on earth by 2060—perhaps the last sustained increase in population the world will see. Cities, and the organizational networks in them, will allow these larger populations to live more productively and to respond creatively and equitably to a host of longstanding challenges—like building and maintaining infrastructure and paying for public services—that will become thornier and more urgent as people become more diverse in every way.
Brent D. Ryan, Associate Professor of Urban Design and Public Policy, Department of Urban Studies and Planning, MIT
Cities represent humankind’s greatest concentration of people, infrastructure, capital, and ideas. As such they have a close, peculiar, and even dangerous relationship with sustainability. Cities hold not only the greatest potential for generating the ideas critically necessary to reduce humankind’s impact on the earth, but also the greatest threat of total disaster should humanity not be able to accommodate nature’s needs.
Most would agree that cities are our most promising sites for innovation in both scientific and political spheres. Living in a city obliges one to understand and appreciate human diversity, pluralism’s value, liberal government’s importance, and, most of all, the city’s delicate balance of art, environment, technology, and tolerance. Cities promote dialogue, dialogue promotes ideas, and ideas promote solutions. Cities, in other words, are the keys to sustainability. Were more citizens of the developed world and particularly the United States to live in cities, I think sustainability policies and solutions would be far less distant a reality than they are today.
New York City’s recent disastrous experience with Hurricane Sandy is but a modest preview of the risks, expenses, and crises that lie ahead for the world unless carbon dioxide reductions are taken seriously and occur immediately. Cities, wonderful and vulnerable as they are, provide our best chance to change stubborn minds, change political and technological realities, and change the world’s future.
Saskia Sassen, Robert S. Lynd Professor of Sociology, Department of Sociology, Columbia University
Our global geopolitical space is getting crowded. Many new actors have been added over the last three decades, from WTO to the International Criminal Court. And older actors, such as the IMF and civil society organizations, have gained prominence. Over a hundred other regulatory bodies have emerged and aspire to govern our increasingly globalized economies, polities, criminalities, terrorisms, epidemics, and environmental destructions. None of these have fully replaced national governments because these are far more complex in their all-encompassing functions and (at times at least) capabilities.
But now we see emerge a very different network of complex actors with multiple capabilities who find themselves at the forefront of many of our major challenges—from the environment to terrorism. They are cities, especially global cities. It is not that the diverse leaderships of cities want to compete with national states in our global geopolitical space. They don’t. They simply have had to address these major challenges because it is in cities where they become acute, urgent, empirical—one can act on them directly. It is this practical and urgent situation of city leaderships which is giving them such traction, often informal, in the new global geopolitics.
Thomas J. Sugrue,
David Boies Professor of History and Sociology, Director of the Penn Social Science and Policy Forum, University of Pennsylvania
Over the last decade, observers have celebrated the “comeback” of big cities, pointing to accelerating gentrification, the revitalization of downtowns, and the growing presence of hipsters and the “creative class” in once forlorn neighborhoods. The unspoken assumption is that attracting the young, white, and wealthy back to cities will benefit working and middle-class urbanites. Yes, growing the population of wealthy residents and businesses can help fill city tax coffers and improve public services. But the benefits of growth won't simply trickle down. The challenge for 2014, and beyond, will be developing growth strategies to challenge deep and urban inequality. Long -term, sustainable growth for the majority of city residents means better jobs, higher wages, investments in struggling middle- and working-class neighborhoods, and improved public education. Trendy coffee shops and four-star restaurants, luxury apartments, and public policies that favor downtown growth over neighborhood health and sustainability might get a lot of good press but they won't make life better for those who are clinging onto low-wage jobs, sending their children to underfunded schools, and struggling to make ends meet.
Catherine Tumber, Visiting Scholar, School of Public Policy and Urban Affairs, Northeastern University; and Fellow, Gateway Cities Innovation Institute, MassINC
I’m not sure how useful it is to speak of “the city” categorically—especially with regard to sustainability, which involves stewarding the assets and challenges at hand in a particular historical place. Of course, as population centers, all cities should take measures to husband their resources and reduce their carbon emissions, such as upgrading their waste and water management systems, improving their buildings’ energy efficiency, and securing low-carbon transportation alternatives to the car. But with regard to economic development, it is particularly true that one size does not fit all. What works in New York will not necessarily play in Peoria.
The role of the city, then, is to chart out a credible guiding vision for green metro development that plays to local strengths, and to cultivate early participatory buy-in by both the citizenry and local and state leadership. So, for example, as U.S. manufacturing undergoes signs of revival, it makes sense that New York State would heavily subsidize a new plant (making solar panels and LED lights) on the former site of Republic Steel in the City of Buffalo rather than on some far-flung, exurban greenfield—or, for that matter, in Brooklyn, where property values are soaring. Smaller industrial cities can ground the productive low-carbon economy in manufacturing and sustainable agriculture in ways large, finance- and high-tech-based cities cannot, thanks to their manufacturing infrastructure, fertile proximate farmland, and productive cultural ethos. City leaders can also help find markets for exports with urban trade partners, push for living wages, and align K-12 education with the local labor market without sacrificing the humanities. For if the past thirty-five years have taught us nothing else, it is that sustainable economic growth requires greater equity and more judicious habits of civic thought.
Susan Wachter, Richard B. Worley Professor of Financial Management, Professor of Real Estate and Finance, The Wharton School, and Co-Director, Penn Institute for Urban Research, University of Pennsylvania
With their dense form, cities have the potential to minimize humankind’s footprint on earth and contribute to a sustainable future but, to do so, they must provide the public goods and infrastructure that make inclusive growth possible.
In order to achieve inclusive growth, cities must provide essential public goods such as education, sanitation, clean water, and transportation (for access to jobs)—elements to improve life chances for all people. With these resources, global urbanization can produce a virtuous dynamic: an increasingly educated population with investment in children supporting future sustainable economic development.
As incomes rise, citizens place a higher value on the environment and therefore demand more environmentally aware policies. Additionally, with sufficient economic resources, urban families no longer need to rely on their offspring as insurance mechanisms, which expands opportunities for education and promotes investment in human capital. Building out the earth over the next several decades requires public goods today to support inclusive and environmentally sustainable growth going forward.
Richard Weller, Professor and Chairman, Martin and Margy Meyerson Chair of Urbanism, Landscape Architecture
Since their inception, cities have survived through exploitation of their landscapes, simply moving further afield when resources run out. Given the obvious geographical limits to that historical process, we must—as I think is implied by "sustainability”—redesign the problem at its source. As Herbert Giradet says, “There will be no sustainable world without sustainable cities.” This implies that in this century our cities need to evolve from wasteful machines into more eco-logistical metabolisms.
We now strive for urbanization with a reduced overall ecological footprint as a matter of global survival and global justice. As such, we are now concerned with redesigning the city’s metabolic systems: its flows of food, water, energy, and its products and by-products. To understand and map a city in terms of these flows is to chart complicated material and cultural relationships across local, regional, and global scales. The value in doing this is to develop a systemic understanding of the city and its broader relationships to better determine where design intelligence is most needed.
I hasten to add that this logistical tracking of the global city’s systems is not a crudely instrumental exercise, for the city is first and foremost a place of desire, mythology, and theater. If sustainability is prosecuted as merely instrumental or punitive it will not succeed. The sustainable city is the desirable city.
Laura Wolf-Powers, Assistant Professor, City & Regional Planning, School of Design, University of Pennsylvania
To make the world we want, we need the vibrancy, the density, the productivity, the intellectual and artistic combustibility, of cities.
To make the cities we want, we need investors, large and small. Investors who recognize the embodied energy in existing infrastructure, the latent value in historic buildings and underutilized land, and the immense potential of city-dwellers—those astonishingly improvisational, resourceful, indefatigable people who activate the potential of urban places.
Alongside investors, we need a strong, mobilized, high-capacity public sector. A public sector of and for the public, intent on providing public goods without which there would be no investment opportunities. Intent on ensuring excellent public education and beautiful, unexpected, inclusive public spaces. A public sector ready to make it possible for all people who work to earn a living that makes them and their families self-sufficient and proud. We need strong civic organizations too—but first we need a public sector populated with leaders capable of building cities where growth and equity are interdependent and mutually reinforcing.
From cities like these—cities where place-conscious investors are working symbiotically with a public sector dedicated to both growth and equity—sustainable growth in the twenty-first century will emerge.