1. Sustainable Cities
Chapter 22

2. 22-1 What Are the Major Population Trends in Urban Areas?
Concept Urbanization continues to increase steadily and the numbers and sizes of urban areas are growing rapidly, especially in developing countries.

3. Half of the World’s People Live in Urban Areas
Urbanization
The creation and growth of urban areas
Measured as the percentage of people living in an urban area
Urban growth
The rate of increase of urban areas
Natural increase (births over deaths)
Immigration from rural areas

4. Half of the World’s People Live in Urban Areas
Immigration from rural areas as a result of…
People pulled to urban areas from rural areas:
In search of jobs, food, housing, education, better health care, entertainment, etc.
People pushed from rural areas to urban areas:
Poverty, lack of land for growing food, declining agricultural jobs, war, famine, etc.

5. Half of the World’s People Live in Urban Areas
Four major trends:
Proportion of global population living in urban areas is increasing
30% urban in 1950, 60% urban by 2030
Urban areas are expanding rapidly in number and size
1970: 2 urban areas with population of 10+ million
2025: 37 urban areas with population of 10+ million
Urban growth is much slower in developed countries than in developing countries
Poverty is becoming increasingly urbanized; mostly in developing countries
One billion people living in slums worldwide

6. Half of the World’s People Live in Urban Areas
Megacities – cities with 10 million or more people
Hypercities – cities with 20 million or more people

8. Case Study: Urbanization in the United States
Four phases between 1800 and 2008 that led to urban population growing from 5% to 79%:
Migration from rural areas to large central cities
Migration from large central cities to suburbs and smaller cities
Half of all urban Americans live in suburbs
Migration from North and East to South and West
80% of U.S. pop. growth occurred in South and West
Migration from cities and suburbs to developed rural areas

9. Case Study: Urbanization in the United States
8 in 10 Americans live in urban areas.
About 48% of Americans live in consolidated metropolitan areas.

10. Urban Sprawl Gobbles Up the Countryside
Growth of low density development on the edges of cities, thus eliminating agricultural and wild lands
Contributing factors to urban sprawl in the U.S.:
Ample land to spread out
Government loan guarantees stimulate growth
Low-cost gasoline; highways encourage vehicle use
Tax laws encouraged home ownership
State and local zoning laws
Multiple political jurisdictions: poor urban planning

11. Urban Sprawl Gobbles Up the Countryside
As they grow and sprawl outward, urban areas merge to form a megalopolis.
Bowash runs from Boston, Massachusetts to Washington, D.C.

12. Natural Capital Degradation: Urban Sprawl

13. 22-2 What Are the Major Urban Resource and Environmental Problems?
Concept Most cities are unsustainable because of high levels of resource use, waste, pollution, and poverty.

14. Urbanization Has Advantages
Cities are centers of economic development, jobs, commerce, education, and transportation.
Urban populations are generally healthier, with better access to medical care, family planning information, education, and social services.
The poor do not have the same access.
Recycling is more feasible and environmental protection is better supported.
People concentrated in an area preserves biodiversity and wildlife habitats.

15. Urbanization Has Disadvantages
Huge ecological footprints, not self-sustaining
Urban areas are only 2% of Earth’s surface but consume 75% of the resources.

16. Urbanization Has Disadvantages
Lack vegetation
Water problems
Very high demand
Deprives surrounding rural areas
Increase flooding from storm runoff
Concentrate pollution and health problems
Pollution levels are greater b/c they cannot be dispersed and diluted as easily
CO2 and NO2 emissions from cars
More easily spread infectious diseases

17. Urbanization Has Disadvantages
Excessive noise
Noise pollution – unwanted, disturbing, or harmful sound that impairs hearing, causes stress, hampers concentration/efficiency, or causes accidents.
Different climate and experience light pollution
Heat generated and solar energy absorbed
Similar to noise, too much light can be harmful

18. Life Is a Desperate Struggle for the Urban Poor in Developing Countries
Extreme poverty forces hundreds of millions of people to live in slums, squatter settlements, or shantytowns where adequate water supplies, sewage disposal, and other services do not exist.
According to a U.N. study, in 2006 about 1 billion people worldwide lived in these conditions.

19. 22-3 How Does Transportation Affect Urban Environmental Impacts?
Concept A combination of plentiful land, inexpensive fuel, and expanding networks of highways in some countries has resulted in dispersed cities whose residents depend on motor vehicles for most transportation.

20. Cities Can Grow Outward or Upward
Land availability determines whether a city must grow vertically or if it can spread out horizontally
Compact cities (Hong Kong, China; Tokyo, Japan)
Dense development, high-rise buildings, mass transit
Dispersed cities (U.S. and Canada)
Plentiful land, cheap gasoline, network of highways, dependence on cars

21. Cities Can Grow Outward or Upward
The urban sprawl of most U.S. urban areas is a prime example of car-centered dispersed cities.
With just 4.6% of the world’s population, the U.S. has almost one-third of the world’s cars.
Passenger vehicles are used for 98% of all transportation.
If Americans doubled their use of mass transit from 5% to 10%, this would reduce U.S. dependence on oil by 40%.
Mass transit: not an option in most cities as a result of the dispersed nature of the growth

22. Motor Vehicles Have Advantages and Disadvantages
Mobility and convenience
Status symbol
Jobs in: production and repair of vehicles and parts, supplying fuel, building roads
Disadvantages
Largest source of outdoor air pollution
Accidents: death and injury
Helped create urban sprawl
Traffic congestion

23. Reducing Automobile Use Is Not Easy, but It Can Be Done
Full-cost pricing: higher gasoline taxes to cover the harmful costs of driving
Tolls on roads, tunnels, and bridges into major cities
Raise parking fees
Car-sharing
Some cities are promoting alternatives to cars:
bicycles, mass transit rail systems, buses, rapid-rail system between urban areas

24. Trade-Offs: Bicycles, Advantages and Disadvantages

25. Trade-Offs: Mass Transit Rail, Advantages and Disadvantages

26. Trade-Offs: Buses, Advantages and Disadvantages

27. Trade-Offs: Rapid Rail, Advantages and Disadvantages

28. 22-4 How Important Is Urban Land Use Planning?
Concept Urban land-use planning can help to reduce uncontrolled sprawl and slow the resulting degradation of air, water, land, biodiversity, and other natural resources.

29. Urban Land-Use Planning
Encourages future urban sprawl
Funded by property taxes
Goal is economic development
Often environmentally destructive
Zoning – Parcels of land are designated for specific uses
Favors high priced projects
Discourages innovation

30. Smart Growth Works
Smart growth can help control growth patterns discourage urban sprawl, reduce car dependence, and protect ecologically sensitive areas.

31. 22-5 How Can Cities Become More Sustainable and Livable?
Concept An ecocity allows people to: choose walking, biking, or mass transit for most transportation needs; recycle or reuse most of their wastes; grow much of their food; and protect biodiversity by preserving surrounding land.

32. Cluster Development Conventional housing development
Bulldoze woods or farmland and build rows of houses on uniform sized lots
Cluster development
Houses concentrated on one portion of the land with the rest used for commonly shared open space.
Cheaper
More aesthetically pleasing
More open recreational space

33. New Urbanism is Growing
There is a growing movement to create mixed-use villages and neighborhoods within urban areas where people can live, work and shop close to their homes.
New urbanism
Walkability
Mixed-use and diversity
Quality urban design
Environmental sustainability
Smart transportation

34. The Ecocity Concept: Cities for People Not Cars
Use parts of the new urbanism ideals to redesign entire cities. Ecocities or green cities:
Allows people to walk, bike, or take mass transit for most of their travel
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; farmers markets