Transitioning to a sustainable urban future

A Thought Leader Series Piece

By Christopher Boone

Chris Boone

Note: Christopher Boone became the Interim Dean of Arizona State University's School of Sustainability in July. He continues to teach in the School of Sustainability and the School of Human Evolution and Social Change. He recently co-edited the book, "Urbanization and Sustainability: Linking urban ecology, environmental justice and global environmental change."

History shows that significant transitions are possible, and these radical changes can have far-reaching impacts on human beings and the environment. In a span of just three human lifespans—roughly 200 years—we have experienced demographic, energy, and economic transitions that have altered the human condition and our relationship with the planet. In the United States in 1800, birth rates were high, but life could be miserably short; people depended on animals, falling water, and wood for energy; and the economy was based on agriculture and resource extraction.

Today in the U.S., families are not large enough to replace the current generation, but people can expect to enjoy long lives; we are utterly dependent on fossil fuels for energy; and the economy is based mainly on services. The implications of these transitions are multi-faceted and complex, but they have contributed to, among other concerns, rising energy and material demands, global climate change, biodiversity loss, and increasing disparities of human well-being.

Today's transition: urbanism

We are now undergoing another transition, the shift to an urban world. Although cities have existed for at least 10,000 years, not until quite recently could a majority of people live in urban centers. England became the first urban country in 1851, meaning more than half of its population lived in cities. The U.S. did not reach the urban threshold until 1920.

Now that half of humanity lives in cities and nearly all of the projected 3 billion in population growth by 2050 is expected to occur in urban environments, it is critically important—as the transition is underway—to think about sustainable pathways forward. This is no easy goal, especially since many of the current sustainability challenges are the result of living in highly urbanized societies. Cities now consume 65 percent of the world's energy and generate 70 percent of global greenhouse gas emissions. In China, people who move from the countryside to its burgeoning cities double their energy consumption and carbon emissions. Higher incomes in cities mean greater demand for resources and higher production of wastes, both of which threaten the health of the world's ecosystems.

The twentieth-century model of urbanization cannot be sustained. Instead we need to promote and guide the best assets of urban life—innovation, opportunities for collaboration and exchange, an educated and healthy citizenry, diversity of people and opportunities, concentration of financial, human, and social capital—to build a desirable, sustainable future. Urbanization is going to happen, and happen on a grand scale. It would be unwise to simply stand on the sidelines and watch it unfold; sustainability depends on the ability and willingness to "bend the curve" rather than hope or wait for the system to correct itself.

Bending the curve

A fundamental principle of sustainability is that action and intervention is necessary in order to avoid potentially catastrophic change. Scarcity of fossil fuels, for instance, may eventually force a transition to a renewable energy portfolio, but the danger in waiting for price signals is the environmental damage and human suffering that will occur as a result of increased and persistent carbon dioxide in the atmosphere. Sea level rise is already underway, and many of the world’s cities located in low coastal elevation zones are especially vulnerable to damage from rising oceans, storm surges, and an inability or unwillingness to plan for climate change hazards. If municipalities pay heed to early warning signals, careful planning can save human lives, property, and resources. Rather than waiting for crises such as Hurricane Sandy or the devastating European heat wave of 2003, cities can “bend the curve” or accelerate a transition to a new, more desirable, and resilient state.

Leapfrogging into healthy pathways

In most rich, industrial countries, urban populations have reached what appears to be an upper plateau of approximately 80 percent of total population. Many of the challenges of sustainable urbanization in these regions will focus on how to retrofit what is already in place. Most new urban growth over the next 50 years will be in Asia and Africa, not in the megacities that attract most attention, but in cities of less than 500,000 in population. Before these cities dot the landscape, there is a huge opportunity to rethink what cities should be, how they should function, and how they can support rather than hinder global sustainability.

Urban centers created in this century do not have to—and indeed should not—follow the models of cities created in the industrial era of the last century. New York, London, and Tokyo invested billions of dollars in concrete, asphalt, steel, and cables to make the industrial city function. The sunk costs of hard or gray infrastructure make it difficult to try new ways to service the city. New cities built around the idea of green infrastructure using ecosystem services to make cities livable and healthy, is a way to "leapfrog" the traditional pathway.

For instance, foresting watersheds can be a more cost-effective way to maintain water quality than an energy intensive water treatment plant. A forested watershed has other co-benefits, such as recreation space, wildlife habitat, and flood control that make a green infrastructure strategy an attractive proposition.

Many cities built in the twentieth century are now struggling to retrofit their transportation infrastructure that was built to make car use as easy as possible, and to change it to support public transit and walkability.

New cities can get ahead of this painful and expensive process by designing from the outset with an emphasis on walkable, transit-oriented urban living. The smart money will be invested in urban design that elevates human well-being and ecological integrity.

Let’s not forget equity

An imperative of sustainability is to consider the well-being of future and present generations. Sustainability actions taken by one city could have the effect of undermining well-being elsewhere or for future generations of city dwellers. Well-intentioned recycling programs for electronics, for example, can mean hazardous living conditions for workers in developing cities.

Cities around the world are "teleconnected" to one another, meaning that an action at one place can have a rapid impact on other cities even at great distances. For a sustainable urban transition, we need to take into account the teleconnected systems of cities that function on a global scale. Sustainability at the gross expense of others is inequitable and unjust and could ultimately undermine the ability of the world to function as an urban earth.

About the author: Christopher Boone is particularly interested in how social and ecological systems interact in urban environments and how to use this knowledge to plan for sustainable futures.  As a professor in the School of Sustainability and School of Human Evolution and Social Change, Boone teaches courses on urban environments, sustainable urbanism, environmental health, and environmental justice. He also serves on the executive committee of the Global Institute of Sustainability’s Central Arizona-Phoenix Long-Term Ecological Research, a National Science Foundation project that studies urban ecosystems. He is a co-editor of the Cambridge University Press book series, New Directions in Sustainability and Society.