22.1 What Are the Major Population Trends in Urban Areas?

Half of the World’s People Live in Urban Areas

• Urbanization: The creation and growth of urban and suburban areas. it is measured as the percentage of the people in a country or in the world living in such areas

• Urban growth

  • Natural increase, in immigration from rural areas

  • Pushed from rural areas to urban areas

  • Pulled to urban areas from rural areas

• Four Major Trends

  • The proportion of the global population living in urban areas is increasing

  • The number and size of the urban regions are mushrooming

    • Megacities

    • Hypercitices

  • Urban growth is slower in developed countries

  • Poverty is becoming increasingly urbanized; most developing countries

Urbanization in the United States

• Four phases between 1800 and 2008

  • Migration from rural areas to large central cities

  • Migration from large major cities to suburbs and smaller cities

  • Migration from North and East to South and West

  • Migration from cities and suburbs to developed rural areas

• Environmental problems decreasing

• Older cities

  • Deteriorating services

  • Aging infrastructures

Urban Sprawl Gobbles Up the Countryside

• Urban Sprawl: The growth of low-density development on the edges of cities and towns

  • Is eliminating surrounding agricultural and wildlands

  • The far-flung hodgepodge of buildings loosely connected only by highways

• Contributing factors to urban sprawl in the U.S.

  • Ample land

  • Federal government loans

  • Low-cost gasoline; highways

  • Tax laws encouraged home ownership

  • State and local zoning laws

  • Multiple political jurisdictions: poor urban planning

• Megalopolis: chain of roughly adjacent metropolitan areas; very large cities

  • Bowash

Urban Sprawl

Land and Biodiversity

• Loss of cropland

• Loss of forests and grasslands

• Loss of wetlands

• Loss and fragmentation of wildlife habitats

Water

• Increased use of surface water and groundwater

• Increased runoff and flooding

• Increased surface water and groundwater pollution

• Decreased natural sewage treatment

Energy, Air, and Climate

• Increased energy use and waste

• Increased air pollution

• Increased greenhouse gas emissions

• Enhanced global warming

Economic Effects

• The decline of downtown Loss of forests and business districts

• Increased unemployment in the central city

• Loss of tax base in the central city

22.2 What Are the Major Urban Resource and Environmental Problems?

Urbanization Has Advantages

• Centers of…

  • Economic development

  • Innovation

  • Education

  • Technological advances

  • Jobs

• Urban residents tend to live longer and have a lower infant mortality rate- better access to medical care, family planning, and social services

• Environmental advantages: recycling is more feasible, reduces stress on wildlife, and saves energy when relying on mass transit

Urbanization Has Disadvantages

• Huge ecological footprints: consume most of Earth’s resources and produces most of the carbon dioxide emissions, high resource input of food, water, and materials resulting in high waste output

• Lack of vegetation: vegetation is destroyed to make way for roads, buildings, and housing therefore cities do not benefit from the natural absorption of air pollution, oxygen output, and shade

• Water problems: water demands increase, deeper well drilling, flooding due to a lot of impermeable surfaces, and destroyed wetlands

• Concentrate pollution and health problems: pollution levels are higher because pollution is produced in a smaller area and cannot be dispersed and diluted

• Excessive noise: urban dwellers are subject to noise pollution- any unwanted or harmful sound that interferes with hearing, causes stress, etc

• Different climates experience light pollution: cities are generally warmer, rainier, and cloudier; the enormous amount of heat is generated by factories, lights, air conditioners, etc.

Life Is a Desperate Struggle for the Urban Poor in Developing Countries

• Slums: areas dominated by tenements and rooming houses where several people may live in a single room

• Shantytowns: shacks are built on the outskirts of town Squatter

• Settlements: people take unoccupied land without permission for survival

• Terrible living conditions

22.3 How Does Transportation Affect Urban Environmental Impacts?

Cities Can Grow Outward or Upward

• Compact Cities: high density like Hong Kong, Tokyo where people get around by foot, bike, or mass transit, many high-rise apartment buildings

• Dispersed Cities: the city is more spread own because of plentiful land, cheap gasoline, and a network of highway systems

• Car-Centered Cities: ample land is available for outward expansion resulting in urban sprawl, and passenger vehicles are the main mode of transportation

Motor Vehicles

Advantages

• Mobility

• Convenient

• Economic gain for car industries

• Helps create urban sprawl

Disadvantages

• Many deaths from crashes

• Increased greenhouse gases

• Increased photochemical smog

• Congestion

Reducing Automobile Use Is Not Easy, but It Can Be Done

• Full-cost pricing: high gasoline taxes

• Difficult to pass in the United States

  • Strong public opposition

  • Mass transit is not an option in most cities

  • Dispersed nature of the U.S.

• Raise parking fees

• Tolls on roads, tunnels, and bridges into major cities

• Car-sharing

• Charge a fee to drive into a major city

• It is working in some cities

22.4 How Important Is Urban Land Use Planning?

Conventional Land-Use Planning

• Land-use planning: To determine the best present and future use of land

  • Encourages future population growth

  • Economic development

  • Revenues: property taxes

  • Environmental and social consequences

• Zoning

  • parcels of land are designated for specific uses

  • Mixed-use zoning

• Smart Growth: a way to encourage more environmentally sustainable development; encourages clustered, mixed-use neighborhoods

  • Reduces dependence on cars

  • Controls and directs sprawl

  • Cuts wasteful resource

Smart Growth Tools

Limits and Regulations

• Limit building permits

• Urban growth boundaries

• Greenbelts around cities

• Public review of new development

Zoning

• Encourage mixed use of housing and small businesses

• Concentrate development along mass transportation routes

• Promote high-density cluster housing developments

Planning

• Ecological land-use planning

• Environmental impact analysis

• Integrated regional planning

• State and national planning

Protection

• Preserve existing open space

• Buy a new open space

• Buy development rights that prohibit certain types of development on land parcels

Taxes

• Tax land, not buildings

• Taxes Tax land on the value of actual use (such as forest and agriculture) instead of on the highest value as developed land

Tax Breaks

• For owners agreeing not to allow certain types of development (conservation easements)

• For cleaning up and developing Planning abandoned urban sites (brownfields)

Revitalization and New Growth

• Revitalize existing towns and cities

• Build well-planned new towns and villages within cities

Preserving and Using Open Space

• Urban growth boundary

  • U.S. states: Washington, Oregon, and Tennessee

• Municipal parks

  • U.S. cities: New York City and San Francisco

• Greenbelts

  • Canadian cities: Vancouver and Toronto

  • Western European cities

22.5 How Can Cities Become More Sustainable and Livable?

New Urbanism is Growing

• Conventional housing development

• Cluster development: High-density housing units are concentrated on one portion of a parcel and the rest of the land is used for commonly shared open space (live, work, play communities)

• New urbanism, old villageism

  • Walkability: most stores and recreational activities located within 10 minute's walk of homes and apartments

  • Mixed Use and Diversity: provides a mix of pedestrian-friendly shops, offices, and homes to encourage people of all ages and races to move in

  • Quality Urban Design: emphasizes beauty, aesthetics, and architect

  • Environmental Sustainability: based on development and minimal env impact

  • Smart Transportation: well-designed train and bus systems connecting neighborhoods, towns, and cities

The Ecocity Concept: Cities for People Not Cars

Ecocities or green cities

• Build and redesign for people

• Use renewable energy resources

• Recycle and purify water

• Use energy and matter resources efficiently

• Prevent pollution and reduce waste

• Recycle, reuse, and compost municipal waste

• Protect and support biodiversity

• Urban gardens; farmer’s markets

• Zoning and other tools for Sustainability

Science Focus: Urban Indoor Farming

• Rooftop greenhouses

  • Sun Works→ designs energy-efficient greenhouses

• Hydroponic gardens

• Skyscraper farms

• Ecological advantages and disadvantages