Chapter 6

The Human Population and Urbanization

Key Concepts

Factors affecting population size

Human population problems

Managing population problems

Urban growth

Resource and environmental problems in urban areas

Transportation in urban areas

Achieving sustainable cities

Is the World Overpopulated?

7.2 - 10.6 billion people by 2050

Limited resources

Environmental impacts (I=PAT)

Some say no- Longer lifespans

Economic growth- stimulated by pop. increase

Religion and population growth

Freedom and population growth

Poverty- 20% people without basic necessities

Ecological footprint

Fig. 6-1, p. 94

Is the World Overpopulated?

Fig. 6-1, p. 94

Click for Current US and World Population

http://www.census.gov/main/www/popclock.html

Factors Affecting Human Population Size

Population change equation

Population change = (Births +Immigration) – (Deaths + Emigration)

Crude birth rate = # live births per 1,000 people per year

Crude death rate = # deaths per 1,000 people per year

Global population growth = 1.2% = 214,000 people per day (97% in developing countries)

Rule of 70: 70/ percentage growth rate = doubling time in years

Doubling time: 70/1.2 = 58 years

Average crude birth rate Average crude death rate

World

All developedcountries

All developingcountries

Developingcountries

(w/o China)

21

9

11

10

24

8

27

9

Average Crude Birth and Death Rates

World’s birth rate = 2.1%

World’s death rate = 0.9%

World’s pop. Growth rate = 1.2%

Crude Growth Rate ÷ 10 = % Growth Rate

Average crude birth rate Average crude death rate

Africa

LatinAmerica

Asia

Oceania

UnitedStates

NorthAmerica

Europe

3814

22

6

20

7

18

7

14

8

148

10

12

Average Crude Birth and Death Rates

Animation

Current and projected population sizes by region.

How Did the Human Population Increase So Rapidly?

1. Human intelligence and adaptation- enabled expansion to diverse habitats & new climate zones

2. Agriculture - feeds more people per unit area

3. Medical technologies and sanitation- controls infectious disease

Describing Population Changes Replacement-level fertility=

# children a couple must bear to replace themselves (approx 2.1 - 2.4)

Total fertility rate (TFR)= average # children woman has in her reproductive years (2005 TFR = 2.7) (TFR in MDCs = 1.6 : LDCs = 3.0)

Projecting global populations: 2050 projected pop. = 7.2-10.6 billionMost growth (97%) expected in developing countries

US fertility rates- see figure 6-4, p. 98

World Population Projections

Fig. 6-2, p. 96

Fig. 6-4, p. 98

US Fertility Rates (1917-2005)

47 years

77 years

8%

81%

15%

83%

10%

98%

2%

99%

10%

52%

$15

$3

1.2

5.8

1900

2000

Life expectancy

Married women workingoutside the home

High school graduates

Homes with flush toilets

Homes with electricity

Living in suburbs

Hourly manufacturing jobwage (adjusted for inflation)

Homocides per100,000 people Fig. 6-5, p. 99

Major Changes in US Society (1900-2000)

Factors Affecting Birth Rates and Fertility Rates ***

Child labor- very important in developing countries

Cost of raising and educating children - more expensive in developed countries

Availability of pension systems - pensions reduce need for children to support in old age

Urbanization- better access to family planning services in cities

Education and employment of women - TFR drops with increasing education & employment opportunities

Infant mortality rate - Directly proportional to TFR

Average age of marriage- Fewer children when marriage age ≥ 25 years

Abortion- 46 million abortions yearly (20 million illegal)

Availability of birth control

Culture, religious values, and traditions

Extremely Effective

Highly Effective

Total abstinence

Sterilization

Vaginal ring

IUD with slow-releasehormones

IUD plus spermicide

Vaginal pouch(“female condom”)

IUD

Condom (good brand)plus spermicide

Oral contraceptive

100%

99.6%

98-99%

98%

98%

97%

95%

95%

93%

Very Effective Birth Control Methods

Effective

Cervical cap

Condom (good brand)

Diaphragm plusspermicide

Rhythm method (Billings,Sympto-Thermal)

Vaginal sponge impreg-nated with spermicide

Spermicide (foam)

89%

86%

84%

84%

83%

82%

Mostly Effective Birth Control Methods

Moderately Effective

Unreliable

Spermicide (creams,jellies, suppositories)

Withdrawal

Rhythm method (dailytemperature readings)

Condom (cheap brand)

Douche

Chance (no method)

75%

74%

74%

70%

40%

10%

Least Effective Birth Control Methods

Factors Affecting Death Rates

Life expectancy: global average years = 69

Infant mortality rate = # of babies out of every 1,000 who die before 1st birthday** Best single measure of a society’s quality of life (reflects nutrition, health care)46 countries have lower infant mortality rates than USA

Improvements: Food, medicine, nutrition, medicine, sanitation, hygiene, water supply

Immigration into the US 41% of annual population growth

Source of immigrants into the USPre 1960: Mostly EuropePost 1960: Latin America (53%), Asia (25%), Europe (14%)

Arguments to reduce immigration: 58% support• Allow population to stabilize • Reduce environmental impact

Arguments for immigration• “Give me your hungry, your tired your poor…’• Tax revenues $$$• immigrants occupy menial, low-paying jobs• After 2020 workers will be needed as Boomers retire

Fig. 6-6, p. 102

Expanding RapidlyGuatemala

NigeriaSaudi Arabia

Male Female

Prereproductive ages 0-14 Reproductive ages 15-44 Postreproductive ages 45-85+

Population Age Structures

Male Female Male Female Male Female

Expanding SlowlyUnited States

AustraliaCanada

StableSpain

AustriaGreece

DecliningGermanyBulgaria

Italy

In 2005, 29% of people on planet were younger than 15 years old

1.5 - 3% 0.3 - 1.4% 0 - 0.2% Negative growth

Animation

Examples of age structure interaction

Fig. 6-8, p. 103

Tracking the US Baby Boom Generation

Animation

U.S. age structure interaction.

Effects of Population Decline 40 nations have stable or declining populations

UN predicts that pop of most develop countries will stabilize by 2050 (not USA)

Rapid declines can create severe social and economic problems

Labor and social security problems

Social and economic impacts of AIDS

Solutions: Influencing Population Size

***Demographic transition

Family planning

Improve health care

Empowering women- worldwide, women account for 66% of hours worked, but receive 10% of world’s income. See stats of p.138

Developing national population policies

Improve education, especially for women

Increase involvement of men in parenting

Reduce poverty

Reduce unsustainable consumption

Fig. 6-10, p. 105

Stage 1Preindustrial

Stage 2Transitional

Stage 3Industrial

Stage 4Postindustrial

Low Increasing Very high Decreasing Low Zero Negative

Birth rate

Total population

Death rate

Growth rate over time

Demographic Transition

Low

High

Rel

ati

ve

po

pu

lati

on

siz

e

Bir

th r

ate

an

d d

eath

rat

e(n

um

ber

per

1,0

00 p

er

yea

r)

0

10

20

30

40

50

60

70

80

Animation- Demographic transition model

Case Study: Hindrances to Family Planning Programs in

India

Poor planning of family planning programs

Bureaucratic inefficiency

Low status of women

Extreme poverty

Lack of administrative and financial support

Case Study: Family Planning in China

Economic incentives- extra food, larger pensions, better housing, $$

Free medical care for participants

Preferential treatment for participants- free school tuition

Very coercive and intrusive- free sterilization, contraception,

Human rights violations- gender imbalance, abortions, infanticide

China’s Pop could peak in 2040, then decline

Percentageof world

population

Population

Population (2025)(estimated)

Illiteracy (%of adults)

Population under age 15(%)

Population growth rate (%)

Total fertility rate

Infant mortality rate

Life expectancy

GDP PPP per capita

17%20%

1.1 billion1.3 billion

1.4 billion1.63 billion

47%17%

36%22%

1.6%0.6%

3.0 children per woman (down from 5.3 in 1970)1.7 children per woman (down from 5.7 in 1972)

6427

62 years 71 years

$2,880 $4,980

Demographic Data on India and China

8147

Percent living below $2 per day

Urbanization and Urban Growth

Urban and rural populations

Rural migration to urban areas

Megacities and megalopolises

Poverty and shantytowns

Patterns of urbanization

Fig. 6-11, p. 108

Los Angeles13.3 million14.5 million

Mexico City18.3 million20.4 million Sao Paulo

18.3 million21.2 million

Buenos Aires12.1 million13.2 million

New York16.8 million17.9 million

Cairo10.5 million11.5 million

Lagos12.2 million24.4 million

Mumbai(Bombay)16.5 million22.6 million

Karachi10.4 million16.2 million

Dhaka13.2 million22.8 million

Calcutta13.3 million16.7 million

Jakarta11.4 million17.3 million

Beijing10.8 million11.7 million

Tokyo26.5 million27.2 million

Shanghai12.8 million13.6 million

Osaka11.0 million11.0 million

Manila10.1 million11.5 million

Major Urban Areas of the World

Delhi13.0 million20.9 million

Megalopolises of Bowash and Chipitts

US Urbanization

Initial migration to large central cities

Later migration from large cities to suburbs

Migration from north and east to south and west

Recent migration back to rural areas

Advantages and disadvantages of US urban areas

Major Urban Areas of the US

Fig. 6-12, p. 109

See Fig. 6-14, p. 110

Some Undesirable Effects of Urban Sprawl

Human Healthand Aesthetics

Contaminated drinking waterand air

Noise pollution

Sky illumination at night

Traffic congestion

Weight gain

Some Undesirable Effects of Urban Sprawl

WaterIncreased runoff

Increased surface water andgroundwater pollution

Increased use of surface waterand groundwater

Decreased storage of surfacewater and groundwater

Increased flooding

Decreased natural sewagetreatment

Some Undesirable Effects of Urban Sprawl

SF Bay region growth animation

Animation

Advantages of Urbanization (especially in Developed Countries)

Jobs

Education

Better access to health care

Some environmental advantages

Biodiversity may be preserved in some rural areas

Disadvantages of Urbanization

Resource use and waste

Reduction in vegetation

Water supply problems and flooding

Don’t grow food

Air, noise and water pollution

Disease, poverty, crime and accidents

Microclimates: Urban heat islands

© 2006 Brooks/Cole - Thomson

Fig. 6-15, p. 111

Inputs Outputs

Energy

Food

Water

Rawmaterials

Manufacturedgoods

Money

Information

Solid wastes

Waste heat

Air pollutants

Water pollutants

Greenhouse gases

Manufactured goods

Noise

Wealth

Ideas

Urban Areas as Open Systems

© 2006 Brooks/Cole - Thomson

Fig. 6-16, p. 112

Noise Levels (in dbA)

Permanent damagebegins after 8-hour

exposure

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

85

Normalbreathing

Whisper

Quietrural area

Quietroom

Rainfall

Normalconversation

Vacuumcleaner

Averagefactory

Lawnmower

Chainsaw

Rock music

Thunderclap(nearby)

Earphonesat loud level

Air raidsiren

Boomcars

Militaryrifle

Urban Areas as Open Systems

Extreme Poverty in Urban Areas

Fig. 6-17, p. 113

Transportation and Urban Development

Compact and dispersed cities

Personal automobiles

Motor vehicles in the US

Advantages and disadvantages of motor vehicles

Reduction of motor vehicle use

Alternatives to motor vehicles

See Fig. 6-18, p. 115

Advantages Disadvantages

Affordable Produce nopollution Quiet Require little parking space Easy tomaneuver intraffic Take fewresources tomake Very energyefficient Provide exercise

Little protectionin an accident Do not protectriders frombad weather Not practical fortrips longer than8 kilometers(5 miles) Can be tiring(except for electricbicycles) Lack of secure bikeparking

Bicycles

Trade-Offs

Tradeoffs of Bicycles

Fig. 6-19, p. 116

Advantages Disadvantages

More energyefficient than cars

Produce less airpollution than cars

Require lessland than roadsand parkingareas for cars

Cause fewerinjuries anddeaths than cars

Reduce carcongestion incities

Expensive tobuild andmaintain

Cost effectiveonly alonga denselypopulatednarrow corridor

Commit riders toTransportationschedules

Can cause noiseand vibrationfor nearby residents

Mass Transit Rail

Trade-Offs

Tradeoffs of Mass Transit Rail

Fig. 6-20, p. 116

Advantages Disadvantages

More flexiblethan rail system

Can be reroutedas needed

Cost less todevelop andmaintain thanheavy-railsystem

Can greatlyreduce car useand pollution

Can lose moneybecause theyneed low faresto attract riders

Often get caughtin traffic unlessoperating inexpress lanes

Commit ridersto transportationschedules

Noisy

Buses

Trade-Offs

Tradeoffs of Buses

Fig. 6-21, p. 116

Advantages Disadvantages

Can reduce travel by car or plane

Ideal for trips of 200–1,000kilometers (120–620 miles)

Much more energy efficient per rider over the same distance than a car or plane

Expensive to run and maintain

Must operate along heavily usedroutes to be profitable

Cause noise and vibration for nearby residents

Rapid Rail

Trade-Offs

Tradeoffs of Rapid Rail

Making Urban Areas More Livable and Sustainable

Land-use planning (Smart Growth)

Walkability

Environmental sustainability

Smart transportation

Ecocities

Reduce pollution and waste

Protect biodiversity

Curitiba, Brazil

Limits and Regulations

• Limit building permits

• Urban growth boundaries

• Green belts around cities

• Public review of new dvlmt

Zoning• Encourage mixed use

• 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 new open space

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

Taxes• Tax land, not buildings

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

Tax Breaks• For owners agreeing legally to not allow certain

types of development (conservation easements)

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

Revitalization and New Growth

• Revitalize existing towns and cities

• Build well-planned new towns and villages

within cities

Smart Growth Tools

Solutions

Fig. 6-17, p. 117

Smart Growth

Fig. 6-23, p. 118

WorkersInterdistrict Direct FeederExpress

City center

Bus System of Curitiba,

Brazil

City center