As we face global challenges of sustainability, are cities part of the problem or part of the solution?

By Katherine Phan, B.S. Computer Science, Class of 2017

Congested, polluted, unsustainable: these are words that have been used to describe San Francisco and other cities that share the same issues surrounding transportation, air quality, and even sanitation. Growing cities around the world have contributed to the majority of global ecological deterioration: it is estimated that they have added to 75% of global carbon dioxide emissions, affordable transportation does not exist in a majority of most cities; and there is not enough agriculture to affordably and fairly feed everyone in the world. Though shelter is a human right, homelessness is also pervasive in many developed cities--for example, San Francisco’s shelters can barely accommodate half of the city’s homeless population.6 As cities grow in size (with up to 66% of the world’s population living in one by 2050), so will these issues, causing escalating damage nationally and globally.

Yet though they’ve contributed to their fair share of human rights issues (water quality, air quality, shelter), cities are an important center of development, and should be the focus of most urban planners in the near future.  Cities are also extremely important for developing solutions to sustainability challenges, due to the high density of people, which could offer more potential to scale up to other cities. Grouping large populations together actually increases transportation efficiency, and cities have already been improving carbon emissions per capita. According to Citylab, “twelve large metros – including New York, (2.3 tons per person), Los Angeles (1.8 tons), San Diego (1.9 tons), Phoenix (1.9 tons), Washington, D.C. (2.3 tons), Miami (2.2 tons) and Seattle (2.2 tons) – rank among the 50 lowest emitting metros.” Abroad, Barcelona is converting itself to a pedestrian city, in which cars are banned within a series of “superblocks” to eliminate traffic from approximately 60% of roads. Similarly, Los Angeles, a city with double the population, has successfully implemented similar “road diets” that reduce the number of car-only roads, decreasing the number of pedestrian and cyclist collisions without decreasing traffic flow. Though each city has its own cultural idiosyncrasies, they all share similar urban systems properties; one solution in Gresham, OR can be expanded to Seattle, and to San Diego, and so forth.

It may be easy to categorize cities as either strictly part of the problem, or pinpoint them as the sole solution for the future, but population density is a fundamental property of urban systems. Thus, urban planners should understand the ever-growing importance of developing cities for high volumes of people; with an exponentially increasing world population and the rise of “mega-cities”, it is imperative to implement the correct infrastructure and policy solutions. Failing to do so is to risk the consequences of more flawed approaches to wicked problems, and to risk the slow but sure demise of the city, the environment, and humankind.