Cities are nodes, complex places characterized by interconnections, and are often centers for innovation, cultural diversity, and art. They are often engines of economic growth and centers of political power. But the dense concentration of people combined with many complicated systems of cities can make solving problems difficult. Cities can be places of poverty, violence, and environmental decay. The world is more urbanized than ever, and experts expect the percentage of people living in cities to continue growing. Consequently, understanding and solving urban challenges will continue to be important work for geographers.

Urban Challenges

While people with great wealth concentrate in cities, so do people with little wealth. Urban poverty exists throughout the world. It is found from inner cities of core countries to squatter settlements and favelas of less-developed countries. According to a United Nations report, about one-sixth of the world’s population lives in urban poverty, and mostly in developing countries. The role of cities in more-developed countries has changed rapidly, shifting from centers of industry to centers of services. Conversely, in less-developed countries, cities have experienced problems brought on by rapid industrialization and growing numbers of new migrants.

Urban Housing Issues in Core Countries

In the developed world, housing for inner-city poor residents is characterized by at least three problems -poor quality, insufficient availability, and significant unaffordability. Often the physical conditions of the buildings need updated to be safe. Proper maintenance and repairs of plumbing, electrical systems, roofing, stairwells, and heating systems are often unaffordable to inner city residents. Landlords often delay making expensive repairs, so over time, the overall quality of the housing suffers. ‘This process is often visible in the transitional areas of cities, as well as in ethnic enclaves, since both have a high percentage of renters. In European cities, these issues often occur near the edge of cities where mass transit lines end and rent is less expensive. Some geographers contend that in many European and North American cities, poorer residential areas are concentrated near industrial regions built on the eastern side of cities. Rents are lower in these areas in part because the wind usually blows east, sending air pollution and industrial smells through these neighborhoods.

Women are more numerous than men in large, central cities in North America. One reason for this disparity is the high number of female-headed households. These women and their children are more likely to be poor than men. According to the U.S. Census Bureau in 2018, 56 percent of the U.S. population living in poverty were women. Hence, women concentrate in areas where housing is the least expensive, even if these areas often have higher crime rates. The lack of good schools, parks and playgrounds, and availability of day care options, compound the problems faced by women and their children.

Housing Discrimination and Segregation in the United States

For the poor in the United States, housing opportunities have suffered because of decay in central cities. Neighborhoods go through cycles of change (see Topic 6.6), culturally and in land use. During much of the 20 century in the United States, housing discrimination was legal.

At the neighborhood scale, redlining, the process by which banks refuse loans to those who want to purchase and improve properties in certain urban areas, was common. Historically, minorities and the poor were the predominant inhabitants of neighborhoods where loans were commonly denied. Banks and federal government loan agencies considered investments in these areas too risky. The term originated as these lending institutions identified these no-loan areas by red lines on maps. Redlining reinforced the downward spiral of struggling and predominately minority neighborhoods. Minorities’ inability to get loans significantly limited homeownership and often resulted in higher poverty rates. Laws now restrict redlining so that denial of a loan cannot happen for racial or cultural reasons.

Other discriminatory laws and practices existed. It was legal for landowners or real estate agents to deny selling or renting property to people based on race, ethnicity, gender, marital status, or religion. Most of the suburban neighborhoods in the United States denied minorities the right to buy homes. This practice prevented minorities from buying less-expensive homes in the suburbs, thereby forcing them to rent because they could not afford the more expensive land and houses closer to the city center.

These practices are now illegal in the United States because of the Fair Housing Act of 1968, but discriminatory policies have impacted the spatial arrangements of U.S. cities dramatically. Most economists argue that home ownership is a key factor for individual wealth. While minority homeownership has improved, the legacy of discriminatory policies still exists according to U.S. census data:

• In 1900, fewer than 20 percent of African Americans owned a home compared to over 46 percent of White people.
• In 2019, over 73 percent of White Americans owned the home they lived in compared to 42 percent of African Americans and 47 percent of Hispanics and Latino Americans.

Racial segregation in housing occurs when people live in separate neighborhoods based on their ethnicity or race. Segregation can occur voluntarily but often occurs involuntarily. In particular, throughout U.S. history, many communities had neighborhoods where African Americans could live and neighborhoods where they could not. Such segregation was enforced through real estate practices, traditions, and violence.

One of these practices was blockbusting. This is when people of an ethnic group sold their homes upon learning that members of another ethnic group were moving into the neighborhood. In U.S. history, often middle-class White families left when African American or Hispanic families moved into neighborhood. Investors would buy houses at low prices and either resell or rent them to minorities for a large profit.

Segregated neighborhoods can sometimes become ghettos, areas of poverty occupied by a minority group as a result of discrimination. Residents who live in ghettos often feel trapped because of social or political factors or a lack of economic opportunities. ‘These neighborhoods have a high percentage of residents who rent, poorly maintained buildings, fewer businesses, and underfunded education and other government services.

Government Support for Affordable Housing

Governments have responded to the shortage of low-income housing in various ways. The federal government provides financial subsidies to help low-income residents with the cost of housing. London, New York City, Denver, and other cities have rent control policies that keep some affordable units available when a neighborhood improves. Inclusionary zoning practices offer incentives for developers to set aside a percentage of housing for low-income renters or buyers. However, critics point out that these policies reduce incentives for investments in new housing.

One reason for the shortage of affordable housing in urban neighborhoods is the cost of constructing and managing a new building can be greater than the profits a business can make. Governments and charitable groups, in both the United States and other countries, often step in to provide assistance, either by building and operating housing or by providing subsidies for others to do so.

These public housing developments-sometimes called “projects”-were first built in areas of the inner city where other structures had been torn down. Many provided decent housing and a solid sense of community. However, these buildings were often high-rise apartments, which concentrated poverty in a small area within the city. These areas experienced problems common in other urban neighborhoods where the poor were clustered, such as drug use, high crime rates, and poor maintenance.

In some cities, community leaders used a scattered site approach to alleviate the problems of public housing. In this approach, of the city or government provided rental assistance for individuals to disperse public housing throughout the area. This allowed children access to better local schools and older residents access to amenities in wealthier neighborhoods.

The scattered-site approach has faced opposition from the “not-in-my-backyard” response. People fear that adding public housing near them will reduce property values and create problems for local communities and schools.

Urban Renewal

As residents in the United States moved to the suburbs after World War II, inner cities suffered from urban decay, high crime rates, and increased poverty. During the 1960s and 1970s, many city governments in the United States adopted the policy of urban renewal. The policy allowed governments to clear out the blighted inner-city slums, which usually displaced the residents to low-income government housing complexes, and built new development projects. Governments often use the legal concept of eminent domain which allows the government to claim private property from individuals, pay them for the property, and then use the land for the public good. The practices of urban renewal and eminent domain happen in all countries but they most disproportionately affect minorities and the poor in periphery and semiperiphery countries.

Gentrification

During the 21st century, large numbers of people desired to leave the suburbs and move closer to the urban core. Gentrification is the process of converting an urban inner-city neighborhood from a mostly low-income, renter-occupied area to a predominately wealthier, owner-occupied area of a city. Often gentrifying areas are of mixed-use development and include art districts, coffee shops, commissioned street art, dog parks, and trendy bars and restaurants. Also, these neighborhoods are near the central business district and its many amenities are available by public transportation.

Gentrification occurs mostly in the cities of core countries but is increasingly happening in cities in the periphery. Often the households in gentrified areas are dual-income, no-kids regardless of the level of development of the city in which they are located. The newcomers to gentrified areas are often a combination of three groups:

• young urban professionals with high-paying jobs
• LGBTQ+ looking for neighborhoods that are more inclusive, accepting, and safe
• older couples whose children have moved out

While gentrification includes positive aspects, there are also negative ones. These neighborhoods experience changes in racial and cultural diversity. Gentrification can displace residents, create space that excludes minorities or the poor, and eliminate the historical cultural landscape of previous residents. As land values rise in inner cities along the growing edge of the central business district, low-income and often minority urban residents are pushed out by rising rents or rising taxes. Older residents who own their homes, but live on fixed incomes, can no longer afford to pay taxes and often have to sell their homes and move.

Housing in Periphery Countries

Urbanization has rapidly expanded the population of cities in periphery countries, which has highlighted a lack of quality housing, especially for poorer residents. The periphery of cities often consists of informal settlements, densely populated areas built without coordinated planning and without sufficient public services for electricity, water, and sewage. Residents often lack land tenure, or the legal protection of contracts to show ownership of the land or structures. These areas are also known as urban slums, favelas or squatter settlements in different parts of the world. (See Topic 6.5.) Residents construct housing from whatever materials are available. Bricks and concrete blocks are more durable, but sheets of tin and plastic are also used. Living in these buildings can be dangerous because of questionable building materials and rarely enforced housing codes. In 2013 in Mumbra, India, 74 people died when an apartment building collapsed.

Most informal settlements are in disamenity zones (see Topic 6.5), abandoned land, or undeveloped open spaces such as parks. Zones of abandonment are areas of a city that have been deserted by their owners for either economic or environmental reasons. In some extreme cases, entire cities have been abandoned usually because of disasters such as the nuclear reactor meltdowns in Chernobyl, Ukraine (1986), and Fukushima, Japan (2011).

In most cases, abandonment is the result of economics and impacts different aspects of an urban region. The area will often have empty decaying buildings, poor sanitation, high crime rates, and vandalism. Examples occur in all regions of the world including Detroit, Michigan, or Kowloon, near Hong Kong. Another specific type of abandonment is a brownfield, created when factories leave an area.

A problem facing many poor communities worldwide is environmental injustice, sometimes referred to as environmental racism, the disproportionate exposure of minorities and the poor to pollution and its impacts, plus the unequal protection of their rights under the law. This process is more common in urban settings where poor communities are often located near high-polluting activities. Some governments will limit new high-polluting industries and activities to poor existing neighborhoods. Residents of these neighborhoods often lack the economic and political resources to block new high-polluting development in their neighborhoods, or to even minimize the impacts.

Geographers use GIS technology to map and study the vulnerable impacted populations and some work together with communities to create solutions. Environmental injustice often results in increased health problems, such as birth defects and cancer, as well as shorter average life expectancy.

Gated or Walled Communities

The compact nature of many cities around the world has pushed informal settlements and poorer communities to live in close proximity to the wealthy. One response to this new geographic pattern is the building of walled or fenced neighborhoods with limited access and entry points, called gated communities. They represent a redesign of urban living with an attempt to recapture features more commonly found outside urban areas – safety, quiet, and homogeneity.

Gated communities are growing in cities all around the world. Some have referred to them as citadels, after historic castles and forts built to ensure safety inside the walls amid lawlessness and crime outside. The growth of gated communities can reinforce separation in economics, social status, ethnicity, and even political views. Slums and wealthy gated communities are often close to each other because residents in both groups desire access to the economic center of the city.

Homelessness

All countries of the world face the challenge of homelessness, the condition of not having a permanent place to live. While some unhoused people find temporary shelter with friends or relatives, others live on the streets. In the United States, the unhoused population was once primarily single men, but the problem expanded in the late 20th century to include more women and children. Government, religious groups, and nonprofit organizations responded by building shelters, advocating for public funding to support housing, and helping the unhoused learn new skills and gain access to health care and social services. In cities without strong public transit systems, people who are unhoused have difficulty traveling to available jobs and services.

Services

Shops and services often struggle to survive in urban neighborhoods. If the patrons are poor, prices for services must be low to maintain a customer base in the area. The result is very tight margins with little money available for shop owners to spend on maintenance or improvement of their facilities. The housing decay spreads to the service sector. Public services such as parks and swimming pools might be rare in urban neighborhoods with low tax bases. Private businesses and service providers, such as doctors and dentists, are often scarce in poor neighborhoods. They are particularly scarce in poor, heavily urbanized countries. For example, in Bangladesh, the number of doctors per capita is about one-fifth the number in the United States.

Food Deserts

Access to food stores in urban neighborhoods is often a problem. Grocery stores and supermarkets tend to favor suburban locations, where residents are wealthier and land costs less. Fresh, healthful food may be far less available than lower priced fast food. This results in few choices for poor families beyond fast food. These urban zones that lack food stores are known as food deserts (see Topic 5.11), and they contribute to health problems, such as obesity and diabetes, for poorer urban residents. Many cities are developing programs and systems to bring food into urban food deserts, such as mobile grocery stores and community gardens, and incentives for grocery stores that locate in low-income areas. Some local food groups provide fresh fruits and vegetables at local pop-up markets.

Political Challenges of Urban Regions

Governing urban regions can be challenging because metropolitan areas (see Topic 6.1) are often a collection of adjacent cities and counties each, with its own government but environmentally, economically, and socially connected. Many urban challenges require a regional approach to governance-examples include urban growth, mass transit, road construction, pollution, and homelessness. Regional governance typically requires voluntary coalitions of city governments to address the needs and create plans for the larger region.

Occasionally, special districts (see Topic 4.7) are established to handle long-term regional needs such as transportation, fire, and police districts. The system of federalism has many strengths but its fragmented nature of governance between states, counties, cities, and neighborhoods often makes collaboration difficult. It is challenging to get multiple levels of government to agree on and implement plans for any major project. The benefits of such cooperation are comprehensive plans and shared costs by the various levels of governance. Additionally, with collaboration, economies of scale (reduced per unit cost) are more likely to be achieved in large-scale projects.

Cities with successful regional planning include Portland, Oregon; Minneapolis, Minnesota; and Amsterdam, Netherlands. Amsterdam has developed a regional multi-model transportation system and a large-scale smart-city initiative that limits outward growth while improving the infrastructure and livability of the existing urban regions. Urban planners argue that as networked meta-cities (see Topic 6.2) of over 20 million people continue to increase around the world, regional planning will be required to improve the connectivity, infrastructure, and livability of these urban giants.

Challenges of Urban Sustainability

Cities are becoming the dominant landscape in the world with more than half of the world’s population living in cities. The United Nations predicts that will rise to over two-thirds by 2050. Consequently, the actions of cities are key to living in a more sustainable world. Multiple levels of government will have to work together to deal with the challenges faced by urban areas.

Environmental Problems in Cities

A city and its population affect the environment in many ways. Stresses are placed on nature when people modify the environment and in the way they respond to those changes.

Environmental Effects of Cities

The physical landscape of an urban area affects the natural environment in many ways and often poses challenges to urban sustainability:

• Urban canyons, streets lined with tall buildings, can channel and intensify wind and prevent natural sunlight from reaching the ground.
• Soils are compacted and replaced with structures that are impermeable to water, such as buildings, streets, and parking lots. As a result, rainwater runs off instead of soaking into the ground, causing urban flooding.
• Water demand increases as people move to cities, which can strain existing water resources. Water is often diverted from agricultural use to urban use.
• The concentration of buildings and concrete in the center of a city creates an urban heat island, an area of a city warmer than surrounding areas.

Cities and Wildlife

Wildlife is also affected by urban areas. Cities destroy animal and plant habitats, redirect or replace natural hydrologic (water) systems such as rivers and lakes, and break up ecosystems. The interruption of continuous ecosystems makes it difficult, if not impossible, for animal species to survive. The animals that survive are often in conflict with humans:

• Native animals such as deer, coyotes, skunks, alligators, bears, cougars, monkeys, and leopards cause problems where cities have invaded or abutted their natural territories.
• Urban wildlife such as rats, raccoons, and pigeons can thrive in cities, but they can spread diseases and be a nuisance to people.
• Feral (wild) populations of cats, dogs, snakes, and other former pets that have escaped their human owners or have been abandoned can be dangerous or upset the ecological balance.

Pollution

Rising urbanism also degrades the environment, particularly in less-developed countries that have fewer resources to combat pollution. Industrial and human waste, concentrated in cities will, if untreated, pollute rivers, aquifers, and coastal areas. As countries develop, air pollution increases because of more industrial activity and more emissions from a growing number of cars. Poorer inhabitants in these cities burn charcoal, wood, and kerosene as fuel sources, all of which pollute the air.

In large, urban regions, automobile pollution causes serious concerns. The huge number of commuters to central business districts and surrounding edge cities creates problems beyond congestion. During rush hour, the commuting periods in early morning and in late afternoon or early evening when many people travel to and from work, idling cars on roads increase and concentrate air pollutants in the city. The result is smog, a severe issue in large cities such as Los Angeles, Beijing, Delhi, and Mexico City.

Climatic conditions and the physical geography of cities and surrounding areas, such as mountains, can intensify pollution. For example, mountains surround Mexico City, and during temperature inversions (when a layer of hot air sits above cool air), smog is trapped and concentrated close to the ground for days with negative effects on the health of the inhabitants. According to the World Health Organization, air pollution results in three million deaths a year. One-third of those are in China, where coal is widely used in industry and to heat homes.

Urban Sprawl

Before automobiles became popular, cities tended to grow vertically through taller buildings as population expanded. Since the mid-20 century, cities and their related environment -such as roads and commercial developments- have expanded horizontally across the landscape. This rapid spread of development outward from the inner city is called suburban sprawl.

In the United States, sprawl is most common in fast-growing areas in the Southeast and West. Urban areas experience sprawl for several reasons:

• the availability of automobiles
• the creation of interstate and other high-speed highways
• the presence of inexpensive land outside the urban area

As a city spreads out it has a greater impact on the environment. More land and energy per capita are needed to maintain a sprawling city as compared to a more compact city design. The physical size of a city has a direct correlation with an ecological footprint, or the impact of human activity on the environment. (See Topic 7.8.)

Responses to Urban Sustainability

Urban systems continue to expand and maintain their position as the dominant location where humans live, work, and play. Therefore, geographers continue to study and propose ideas to respond to the challenges that growing cities create.

Regional Planning and Brownfields

Responses to urban challenges often require a regional planning approach (see Topic 6.10) because urban areas spread across large spaces, include multiple cities, and have wide-ranging impacts. Protecting farmland from expanding cities, developing large-scale water and sewage systems, or creating responses to air pollution require collaborative efforts from multiple stakeholders.

On a local scale, remediating and redeveloping land is a critical issue for cities. Industry once thrived in central cities of developed countries. Yet new technologies have decreased the need for workers, which weakened the economic strength of many cities. Also, manufacturing moved to the suburbs, where land was cheaper, and to other countries, where labor was less expensive.

In the United States, sprawl is most common in fast-growing areas in the Southeast and West. Urban areas experience sprawl for several reasons:

• the availability of automobiles
• the creation of interstate and other high-speed highways
• the presence of inexpensive land outside the urban area

As a city spreads out it has a greater impact on the environment. More land and energy per capita are needed to maintain a sprawling city as compared to a more compact city design. The physical size of a city has a direct correlation with an ecological footprint, or the impact of human activity on the environment. (See Topic 7.8.)

Responses to Urban Sustainability

Urban systems continue to expand and maintain their position as the dominant location where humans live, work, and play. Therefore, geographers continue to study and propose ideas to respond to the challenges that growing cities create.

Regional Planning and Brownfields

Responses to urban challenges often require a regional planning approach (see Topic 6.10) because urban areas spread across large spaces, include multiple cities, and have wide-ranging impacts. Protecting farmland from expanding cities, developing large-scale water and sewage systems, or creating responses to air pollution require collaborative efforts from multiple stakeholders.

On a local scale, remediating and redeveloping land is a critical issue for cities. Industry once thrived in central cities of developed countries. Yet new technologies have decreased the need for workers, which weakened the economic strength of many cities. Also, manufacturing moved to the suburbs, where land was cheaper, and to other countries, where labor was less expensive.

As manufacturing moved away, cities were left with unemployed residents and abandoned factories. Brownfields are visual reminders on the landscape of how the centers of cities have changed over time. A typical brownfield consists of dilapidated buildings and polluted or contaminated soils. These are expensive to remove or repair and often remain in cities, devaluing neighboring properties. Brownfields exist in most core countries and in some semiperiphery countries such as China.

If remediated, their locations are increasingly used as redevelopment sites. If the building remains structurally solid, an entrepreneur might renovate it for a new use and keep enough of its exterior so that people know the building’s history. People have converted old factories into apartments, restaurants, recreational facilities, and artisan boutiques.

Redevelopment

The process of urban redevelopment involves renovating a site within a city by removing the existing landscape and rebuilding from the ground up. The process of urban redevelopment usually begins when a local government declares that an area it wishes to develop is blighted, in a deteriorated condition. Eminent domain laws (see Topic 6.10) allow the government to seize land for public use after paying owners the market value for their property. Cities often use these laws to enable the building of new roads or schools, but they can also sell the land to private groups to build hotels, hospitals, or other developments.

While redevelopment initiatives sometimes replace brownfields or low-quality housing with successful enterprises, critics point out that these efforts can cause problems. They can force poor people to leave their homes and communities. Redevelopment can break up and eliminate historic neighborhoods. Private developers are also sometimes given tax-break incentives to purchase and build. By reducing tax revenues on these projects, the city shifts the tax burden to other taxpayers.