Chapter 22: Sustainable Cities

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

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