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