Chapter 18 Notes: The Urban Environment - Creating Sustainable Cities
Chapter 18: The Urban Environment - Creating Sustainable Cities
Introduction
Urbanization is increasing globally, with more people living in urban areas than rural areas since 2009.
This shift emphasizes the need to create livable and sustainable cities.
The chapter explores urbanization, sprawl, city planning, transportation, and environmental impacts.
Central case study: Managing growth in Portland, Oregon, a city known for its urban growth boundary (UGB) and smart growth policies.
Central Case Study: Managing Growth in Portland, Oregon
Oregon faced challenges from sprawling development in the 1970s.
Governor Tom McCall advocated for action against runaway sprawl.
The state legislature passed Senate Bill 100, a land use law.
Required every city and county to create a comprehensive land use plan following statewide guidelines.
Each metropolitan area had to establish an urban growth boundary (UGB).
Urban Growth Boundary (UGB): A line on a map separating areas for urban development from rural areas. Development is encouraged within UGB and restricted beyond it.
The intent was to:
Revitalize city centers
Prevent suburban sprawl
Protect farmland, forests, and open landscapes
Portland's Metro established the UGB in 1979.
Focused growth on existing urban centers.
Promoted communities where people can walk, bike, or use mass transit.
Policies largely worked as intended.
Portland's downtown and older neighborhoods thrived.
Urban centers became denser and more community-oriented.
Mass transit expanded.
Farms and forests were preserved beyond the UGB.
Portland gained international attention for its livability.
Critics view the UGB as an elitist and intrusive government tool.
Ballot Measure 37 (2004): Required the state to compensate landowners if government regulations decreased their land value.
Landowners filed over 7500 claims affecting 295,000 ha (730,000 acres).
The measure threatened Oregon's zoning, planning, and land use rules causing misgivings among voters who initially supported it.
Ballot Measure 49 (2007): Restricted large-scale development outside the UGB that could harm sensitive natural areas but protected small landowners' rights to develop a small number of homes.
In 2010, Metro finalized an agreement with its region's three counties to determine urban growth for the next 50 years.
Apportioned over 121,000 ha (300,000 acres) of undeveloped land into urban reserves and rural reserves.
Boundaries were precisely mapped to provide clarity for landowners and governments.
Our Urbanizing World
In 2009, a turning point: more people lived in urban areas than rural areas.
Urbanization: The shift from the countryside into towns and cities.
Two pursuits became more important:
Making urban areas more livable.
Making urban areas sustainable.
Industrialization has driven urbanization.
Since 1950, the world's urban population has multiplied by more than five times.
Urban populations are growing because the overall human population is growing and more people are moving from farms to cities.
Urbanization has led to technological advances that boost production and spur further industrialization.
United Nations projects a 63% rise in the urban population between now and 2050, while the rural population will decline by 4%.
Urbanization has slowed in developed nations, where 3 out of 4 people already live in urban areas.
Developing nations are urbanizing rapidly, with people moving to cities for jobs and urban lifestyles or to escape ecological degradation.
Demographers estimate that urban areas of developing nations will absorb nearly all of the world’s population growth from now on.
Figure 18.1: Population trends differ between poor and wealthy nations. In developing nations, urban populations are growing quickly, and rural populations will soon begin declining. Developed nations are already largely urbanized, so their urban populations are growing slowly, whereas rural populations are falling.
Environmental Factors Influence the Location of Urban Areas
Location is vital for urban centers, often situated along rivers, seacoasts, railroads, or highways.
Cities develop along trade corridors.
Well-located cities serve as linchpins in trading networks.
They funnel in resources, process them, manufacture products, and ship those products to other markets.
Example: Portland is situated where the Willamette River joins the Columbia River and grew by processing and shipping produce and importing products.
Modern technologies and cheap transportation have allowed cities to thrive even in resource-poor regions.
The Dallas–Fort Worth area prospers from oil-fueled transportation.
Southwestern cities like Los Angeles, Las Vegas, and Phoenix flourish in desert regions by appropriating water from distant sources.
The sustainability of such cities as oil and water become scarce is an important question.
Many cities in the southern and western United States have grown as people have moved there in search of warmer weather, more space, new economic opportunities, or places to retire.
Between 1990 and 2016, the population of the Dallas–Fort Worth and Houston metropolitan areas each grew by about 80%; that of the Atlanta area grew by 96%; that of the Phoenix region grew by 108%; and that of the Las Vegas metropolitan area grew by a whopping 153%.
People have Moved to Suburbs
American cities grew rapidly in the 19th and early 20th centuries due to immigration and increased trade.
By the mid-20th century, affluent city dwellers moved to the suburbs for more space, better economic opportunities, cheaper real estate, less crime, and better schools.
As affluent people moved to the suburbs, jobs followed, hastening the economic decline of downtown districts.
The population of many major cities declined as residents moved to the suburbs.
Portland followed this trajectory, but policies to revitalize the city center helped reboot its growth.
Figure 18.3: Portland grew, stabilized, and then grew again. Jobs in the shipping trade boosted Portland’s economy and population in the 1890s–1920s. City residents began leaving for the suburbs in the 1950s–1970s, but policies to enhance the city center revitalized Portland’s growth.
The exodus to the suburbs was aided by the rise of the automobile, an expanding road network, and inexpensive and abundant oil.
The federal government's development of the interstate highway system was pivotal in promoting these trends.
Suburbs have provided families with space and privacy.
However, suburban growth has spread human impact across the landscape, leading to the disappearance of natural areas.
People commute longer distances and spend more time stuck in traffic.
The expanding rings of suburbs have grown larger than the cities themselves, and towns are merging into one another.
These aspects of growth inspired a new term: sprawl.
Sprawl
Sprawl: The spread of low-density urban or suburban development outward from an urban center.
Urban areas spread outward, exemplified by cities like Las Vegas and Chicago.
Houses and roads supplant more than 2700 ha (6700 acres) of U.S. land every day.
Sprawl results from development approaches with spacious lots far from urban centers.
The average resident of Chicago's suburbs takes up 11 times more space than a resident of the city.
The outward spatial growth of suburbs generally outpaces population growth.
Figure 18.5: Sprawl is characterized by the spread of development across large areas of land. This requires people to drive cars to reach commercial amenities or community centers.
Many researchers define sprawl as the physical spread of development at a rate that exceeds the rate of population growth.
The population of Phoenix grew 12 times larger between 1950 and 2000, yet its land area grew 27 times larger.
Between 1950 and 1990, the population of 58 major U.S. metropolitan areas rose by 80%, but the land area they covered rose by 305%.
Even in metro areas where population declined, the amount of land covered increased.
There are two main components of sprawl:
Human population growth.
Per capita land consumption.
Better highways, inexpensive gasoline, telecommunications, and the Internet have fostered movement away from city centers.
Economists and politicians have encouraged the spatial expansion of cities and suburbs.
What is Wrong with Sprawl?
Sprawl evokes strip malls, traffic jams, homogenous commercial development, and tracts of cookie-cutter houses encroaching on farmland, ranchland, or forests.
Scientific research shows several impacts of sprawl:
Transportation: Constrains transportation options, forcing people to own a vehicle and drive greater distances.
Pollution: Increases pollution by promoting automobile use, contributing to climate change, smog, and acid deposition.
Health: Promotes physical inactivity and obesity.
Land Use: Converts forests, fields, farmland, and ranchland into developed areas.
Economics: Drains tax dollars from communities and funnels money into infrastructure for new development on the fringes.
A 2003 study found that people from the most-sprawling U.S. counties show higher blood pressure and weigh 2.7 kg (6 lb) more for their height than people from the least-sprawling U.S. counties.
Creating Livable Cities
Architects, planners, developers, and policymakers are trying to revitalize city centers and to plan and manage how urbanizing areas develop.
Planning Helps to Create Livable Urban Areas
City planning: Designing cities to maximize their efficiency, functionality, and beauty.
City planners advise policymakers on development options, transportation needs, public parks, and other matters.
Washington, D.C., is the earliest example of city planning in the United States, designed by Pierre Charles L’Enfant with a Baroque-style plan of diagonal avenues cutting across a grid of streets.
A century later, a height restriction was imposed on new buildings.
City planning in North America came into its own at the turn of the 20th century.
Example: Edward Bennett’s Greater Portland Plan proposed to rebuild the harbor; dredge the river channel; construct new docks, bridges, tunnels, and a waterfront railroad; superimpose wide radial boulevards on the old city street grid; establish civic centers downtown; and greatly expand the number of parks.
Regional planning: Deals with the same issues as city planners but on broader geographic scales.
The Portland area’s Metro is the epitome of such a regional planning entity.
Metro and its region’s three counties announced their collaborative plan apportioning 121,000 ha (300,000 acres) of undeveloped land into “urban reserves” and “rural reserves.”
Zoning is a Key Tool for Planning
Zoning: Classifying areas for different types of development and land use. Government restriction on the use of private land.
Planners can guide what gets built where by specifying zones for different types of development.
Zoning gives home buyers and business owners security.
Most people feel that government has a proper and useful role in setting limits on property rights for the good of the community.
Oregon voters passed Ballot Measure 37 in 2004 which shackled government’s ability to enforce zoning regulations with landowners who bought their land before the regulations were enacted. However, many Oregonians soon began witnessing new development they did not condone, so in 2007 they passed Ballot Measure 49 to restore public oversight over development.
Urban Growth Boundaries are Now Widely Used
Urban Growth Boundaries (UGBs): Limit sprawl by containing growth within existing urbanized areas.
Aimed to revitalize downtowns, preserve farms and forests, and ensure access to open space.
UGBs also save taxpayers money by reducing infrastructure costs.
Many other states, regions, and cities have adopted UGBs.
The Portland region’s UGB has worked as intended, preserving farms and forests outside the UGB while increasing housing density inside it.
Rising population pressure led Metro to enlarge the UGB three dozen times since its establishment.
UGBs tend to increase housing prices within their boundaries.
Demand for housing exceeds supply which makes rents soar and low- and middle-income people are being forced out of neighborhoods they have lived in for years as these neighborhoods experience gentrification.
Relentless population growth may thwart even the best anti-sprawl efforts, and livable cities can fall victim to their own success if they are in high demand as places to live.
“Smart Growth” and “New Urbanism” aim to Counter Sprawl
Smart growth: Building up, not out.
Focusing development and economic investment in existing urban centers and favoring multistory shop-houses and high-rises.
A related approach among architects, planners, and developers is new urbanism, which seeks to design walkable neighborhoods with homes, businesses, schools, and other amenities all nearby for convenience.
These neighborhoods are often served by public transit systems.
Transit Options Help Cities
Traffic jams cost Americans an estimated 74 billion yearly in fuel and lost productivity.
To encourage more efficient transportation, policymakers can raise fuel taxes, charge trucks for road damage, tax inefficient modes of transport, and reward carpoolers with carpool lanes.
Bicycle transportation is one key option (Figure 18.8). Portland has embraced bicycles like few other American cities, and today 6% of its commuters ride to work by bike
City has developed nearly 400 miles of bike lanes and paths, 5000 public bike racks, and special markings at intersections to protect bicyclists.
Mass transit systems: Public systems of buses, trains, subways, or light rail.
Mass transit systems move large numbers of passengers at once while easing traffic congestion, taking up less space than road networks, and emitting less pollution than cars.
As long as an urban center is large enough to support the infrastructure necessary, both train and bus systems are cheaper, more energy-efficient, and less polluting than roadways choked with cars.
Figure 18.9: Rail transit consumes less energy (a) and costs less (b) than automobile transit. Bus transit is highly efficient in places and at times of high use (“peak” in figure).
In Portland, buses, light rail, and streetcars together carry 100 million riders per year.
Success Story: Curitiba, Brazil, established a mass transit system with a large fleet of public buses and reconfigured its road system to maximize its efficiency.
Commuters boarding a bus in Curitiba, Brazil.
The United States lags behind most nations in mass transit.
Urban Residents Need Parklands
Natural lands, public parks, and open space provide greenery, scenic beauty, freedom of movement, and places for recreation.
These lands also keep ecological processes functioning.
The High Line Park in Manhattan is an example of a popular city park.
Even small spaces make a difference, such as playgrounds and community gardens.
Greenways along rivers, canals, or old railway lines can provide walking trails, protect water quality, boost property values, and serve as corridors for the movement of wildlife.
America’s city parks arose in the late 19th century as urban leaders established public spaces using aesthetic ideals from European parks and gardens.
Frederick Law Olmsted designed Central Park in New York City and many other parks.
Portland’s quest for parks began in 1900, when city leaders created a parks commission and hired Olmsted’s son, John Olmsted, to design a park system. A full 44 years later, residents pressured city leaders to create Forest Park, which is one of the largest city parks in North America.
Green Buildings Bring Benefits
Buildings consume 40% of our energy and 70% of our electricity, contributing to greenhouse gas emissions.
Green buildings: Structures built from sustainable materials, limiting energy and water use, controlling pollution, recycling waste, and minimizing health impacts on their occupants.
The U.S. Green Building Council promotes sustainable building efforts through the Leadership in Energy and Environmental Design (LEED) certification program.
Although green building techniques add expense to construction, savings on energy, water, and waste can offset the costs.
Portland features several dozen LEED-certified buildings.
Schools, colleges, and universities are leaders in sustainable building.
Urban Sustainability
A sustainable city is one that can function and prosper over the long term, providing generations of residents a good quality of life far into the future.
Urban Centers Bring a Mix of Environmental Effects
Urban living has a complex mix of consequences on the environment.
Urban dwellers are exposed to smog, toxic industrial compounds, fossil fuel emissions, noise pollution, and light pollution.
City residents even suffer thermal pollution, in the form of the urban heat island effect.
Those who receive the brunt of pollution are often those who are too poor to live in cleaner areas.
FAQ: Aren’t cities bad for the environment? Not necessarily.
By clustering people together, cities distribute resources efficiently while also preserving natural lands outside the city. Cities export some of their wastes. In so doing, they transfer the costs of their activities to other regions—and mask the costs from their own residents.
The Science Behind the Story: Research in urban ecology examines how ecosystems function in cities and suburbs, how natural systems respond to urbanization, and how people interact with the urban environment.
Baltimore and Phoenix are centers for urban ecology.
Baltimore scientists can see ecological effects of urbanization by comparing the urban lower end of their site’s watershed with its less developed upper end.
Baltimore research also reveals impacts of applying salt to icy roads in winter.
Figure 1: Streams in Baltimore’s suburbs contain more nitrates than streams in nearby forests, but fewer than those in agricultural areas, where fertilizers are applied liberally.
Researchers are using isotopes to trace where salts in the most polluted streams are coming from. Baltimore is now improving water quality substantially with a 900-million upgrade of its sewer system.
Urbanization also affects species and ecological communities.
Compared with natural landscapes, cities offer steady and reliable food resources.
Urban ecologists in Phoenix and Baltimore are studying social and demographic questions as well.
These studies have repeatedly found that sources of industrial pollution tend to be located in neighborhoods that are less affluent and that are home to people of racial and ethnic minorities.
Resource Use and Efficiency
Cities are sinks for resources, importing nearly everything they need.
Urban communities rely on large expanses of land elsewhere for resources and ecosystem services and burn fossil fuels to import resources and goods.
Cities are highly efficient in distributing goods and services.
The density of cities facilitates the provision of electricity, medical care, education, water and sewer systems, waste disposal, and public transportation. Thus, although a city has a large ecological footprint, its residents may have moderate or small footprints in per capita terms.
Land Preservation
Because people pack densely together in cities, more land outside cities is left undeveloped.
The fact that half the human population is concentrated in discrete locations helps allow space for natural ecosystems to continue functioning and provide the ecosystem services on which all of us, urban and rural, depend.
Innovation
Cities promote a flourishing cultural life and spark innovation and creativity.
This inventiveness can lead to solutions to societal problems, including ways to reduce environmental impacts.
Urban Ecology Helps Cities Toward Sustainability
Cities that import all their resources and export all their wastes have a linear, one-way metabolism.
Proponents of sustainability for cities stress the need to develop circular systems.
Urban agriculture is thriving in many places.
Urban ecology research projects are ongoing in Baltimore and Phoenix.
In 2007, New York City unveiled an ambitious plan to make it “the first environmentally sustainable 21st-century city.”
Since then, Mayor Bill de Blasio has continued the program under a new name, OneNYC, while adding new dimensions to address economic equity.
Closing the Loop
As the human population shifts from rural to urban lifestyles, our environmental impacts become less direct but more far-reaching.
Planning and zoning, smart growth and new urbanism, mass transit, parks, and green buildings all are ingredients in sustainable cities.
Ongoing experimentation will help us determine how to continue creating better and more sustainable communities in which to live.