ap environmental science ch. 22 sustainable cities

Sustainable Cities

Ch. 22

Sustainable Cities

Key terms1. 2.

4 major trends

2. 3. 4. 1.

cons

Urban sprawl

pros

Definition Contributing factors pros cons

Urbanization

Developing nations

solutionsissues

Ecocities - Curitiba Brazil• Planners in 1969 decided to focus on

mass transit rather than cars• Apartments and stores near bus stops

– Busses reach >90% of people easily• No cars in city center

– Good for businesses and health• Parks along river to reduce flooding• Environmental education K-12• Still have squatter settlements

– If they bring a full garbage bag get food and other supplies

Key Terms

• UrbanizationUrbanization – the creation and growth of urban areas and cities

• Urban growthUrban growth – the rate of increase in urban populations– 80% of Americans and over half of all people

in the world live in cities

Mexico City - the second most populous city in the world

Cities Grow by…

• More births than deaths (natural increase)• Immigration

– Rural people move in for jobs, food, housing

4 Major Trends

1. A greater percentage of people are living in urban areas

4 Major Trends2. Urban areas are expanding rapidly in number and size

– Every week 1 million more people are added to urban areas

– 18 megacities – cities with 10 million or more people

• 15 in developing nations

– Hypercities – cities with 20 million or more people

• So far only Toyko is in this group 27 million people

• Mumbai, Lagos (Nigeria), Dakar, Sao Paulo soon

4 Major Trends

3. Urban growth is slower in developed countries than developing

4 Major Trends

4. poverty is becoming increasingly urbanized, mostly in developing countries

– According to U.N. – at least 1 billion people live in slums and shanty towns

Partner Share• What are the 4 trends? (no peeking)

• What might be some benefits to having most humans live in cities?

Urban SprawlUrban Sprawl• Definition: Definition: The growth of low-density development The growth of low-density development

on the outskirts of cities and towns (suburbs)on the outskirts of cities and towns (suburbs)• Big problem in US

– Eliminates ag and wild lands– Far apart shopping centers, housing developments, offices loosely connected by freeways

Contributing Factors1. Plenty of land to do so2. Federal government loan

guarantees for WWII vets for new homes (1950s)

3. Low-cost gasoline and fed. and state funding for highways

4. Tax laws that encourage home ownership

5. Zoning laws that separate residential and commercial real estate

6. Most urban areas have multiple political jurisdictions that don’t work together in planning

Problems with Urban Sprawl

• No or poor mass transit– Encourages people to drive everywhere

• Destroys ag and wetlands• Central city “dies” as businesses move to

suburban areas

Urban Sprawl in and around the U.S. City of Las Vegas, Nevada, from 1973 to 2000

Pros of Suburban Areas

• People like it• Lower crime• Newer schools• Larger homes, yards

Back and ForthPartner Share

• Partner 1 tells Partner 2 their answer• Switch• What kind of area do you live in?

– City/Urban– Suburban– Rural

• Do you think the advantages of a suburban life outweigh its disadvantages?

• How expensive would gas prices have to be to affect this lifestyle?

Hey APEShave the answers to the tasks below

1. Urbanization2. Urban growth3. Urban

Sprawl

A. Growth of low density housing around cities

B. Creation of urban areas

C. The rate at which urban areas growWhat are the 4 trends in

urbanization?

matching

What are 2

pros and 2

cons of urban

sprawl?

?

Objective

• Identify and describe the pros and cons of urbanization and discuss some possible solutions for the cons

Sustainable Cities

Key terms1. 2.

4 major trends

2. 3. 4. 1.

cons

Urban sprawl

pros

Definition Contributing factors pros cons

Urbanization

Developing nations

solutionsissues

Urbanization

Advantages of Urbanization• Economics:

– Good education centers– Industry/commerce– Jobs

• Health:– Longer life expectancies– Lower infant mortality and fertility rates– Better access to medical care

• Environmental:– Easier to recycle– Less land for people so more land for wildlife– Less energy use (if mass transit)

Disadvantages of Urbanization• Pressure of more and more

people increases environmental pressure

• Lots of garbage!• Disconnect from nature – lack

of compassion for it• 1. Huge ecological footprints

– Occupy 2% of the earth’s land but use 75% of its resources and produce 75% of the CO2 emissions

– Not sustainable

Problems

• 2. Large areas of land outside the city must be disturbed to provide the food, minerals, fuel, and wood for people in the city

Open pit mine in Russia

Solutions?

Problems

• 3. Lack of vegetation• Plants give oxygen, moist air, shade,

habitat for wildlife, absorb air pollution, and look nice

Solutions?

Problems• 4. Water

– More people = more water needs

• Deeper wells, more canals• Removes water from rural areas

– Cities by rivers flood• Covered in asphalt• Wetlands used to act like

sponges to absorb this water– Cities in coastal areas lose

coastline• Erosion• Global warming and rising sea

levels– Cities in arid areas getting

even drier - TX

Solutions?

Problems• 5. Pollution Concentrated

– High levels of air & water pollution, solid & hazardous waste

– Nitrogen cycle disrupted due to car exhaust (N in air --> acid rain; urban and sewage runoff --> eutrophication of water ways)

Solutions?

Problems

• 6. Infectious disease spreads more rapidly, especially in poor areas with poor water quality

Solutions?

Problems

• 7. Noise pollution

Solutions?

Problems

• 8. Light pollution - affects sea turtles, migratory birds

Solutions?

Problems

• 9. Cities have their own microclimate– Hotter, wetter, foggier– Heat from factories, a.c., streets– Heat --> more a.c. use --> more greenhouse

gasses --> more heat

Solutions?

What is an economic pro and an economic con of cities?

What is an environmental pro and an environmental con of cities?

What is a human health pro and a human health con of cities?

Partner Share• Which two of the disadvantages of living in

urban areas do you think are the most serious? Why?

Urban Poor in Developing Nations

• ISSUES• ~ 1 billion people live in

slums– several families live in one

room structures

• Live in squatter settlements or shantytowns, or on the streets– Illegal– Not serviced by the city– Government often

bulldozes the settlements down

https://www.youtube.com/watch?v=Qe_Esf8XJ_c

Possible Solutions?• Improve medical care,

schooling, family planning in rural areas

• In Peru and Brazil, recognize existing settlements and give titles to the land– Once people know they can stay

they start improving the land themselves

• Build schools, etc

Silent DebatePartner Share

• Partner 1 – yes – shorter hair• Partner 2 - no• Should squatters around cities of

developing nations be given title to the land they live on? Explain.