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
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
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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