Chapter 7

The Human Population

Scientists Disagree on Earth’s Carrying Capacity

Figure

7.1

Scientists Disagree on Earth’s Carrying Capacity

•The following graphs show theoretical models of food supply and population size.

1. The current world population is

closest to which of the following?

a. 1 million b. 500 million c. 1 billion

d. 7 billion e. 20 billion

1. The current world population is

closest to which of the following?

a. 1 million b. 500 million c. 1 billion

d. 7 billion e. 20 billion

World population clock

Factors that Drive Human Population Growth

• Demography- the study of human populations and population trends.

• Changes in Population Size

• Fertility

• Life Expectancy

• Age Structure

Changes in Population Size• Immigration- the movement of people into a

country

• Emigration- the movement of people out of a country.

• Net migration rate- the difference between immigration and emigration in a give year per 1,000 people in the country.

Changes in Population Size

• Crude birth rate (CBR)= the number of births per 1,000 individuals per year.

• Crude death rate (CDR)= the number of deaths per 1,000 individuals per year.

• National population change (%) =

(CBR - CDR) + (immigration - emigration)

10

A country has a crude birth

rate of 30 and a crude

death rate of 25. If the net

migration rate is 14, what is

the population change of

the country?

Crude Birth Rates

Compared• >30- considered high

• < 18- considered low

• Global = 20

• Germany = 8

• Niger =50

• US= 14

Fertility• Total fertility rate (TFR)- an estimate of the

average number of children that each woman in a population will bear.

• Replacement level fertility (RLF)- the total fertility rate required to offset the average number of deaths in a population and for the current population size to remain stable.

Fertility

• Developed countries- countries with relatively high levels of industrialization and income.

• Developing countries- countries with relatively low levels of industrialization and income of less that $3 per person per day.

Female education

and TFR• Female literacy

and school

enrollment are

correlated with

total fertility rate.

• More-educated

women have

fewer children.

2. RLF for a couple is

a.1.0

b.2.0

c.2.1

d.3.0

e.Varies depending on country

2. RLF for a couple is

a.1.0

b.2.0

c.2.1

d.3.0

e.Varies depending on country

Life Expectancy

• Life expectancy- the average number of years that an infant born in a particular year in a particular country can be expected to live, given the current average life span and death rate of that country.

Life Expectancy

• Infant mortality rate- the number of deaths of children under 1 year of age per 1,000 live births.

• Child mortality rate- the number of deaths of children under age 5 per 1,000 live births.

Age Structure

• Age structure diagrams (population pyramids)- visual representations of age structure within a country for males and females.

3: Which country is undergoing rapid

population growth?

A CB

The Demographic Transition

• The theory of the demographic transition is the theory that as a country moves from a subsistence economy to industrialization and increased affluence, it undergoes a predictable shift in population growth.

The Stages of the Demographic Transition

• Phase 1(Pre-Industrial): Slow population growth because there are high birth rates and high death rates which offset each other.

• Phase 2(Transitional): Rapid population growth because birth rates remain high but death rates decline due to better sanitation, clean drinking water, increased access to food and goods, and access to health care.

• Phase 3 (Industrial): Stable population growth as the economy and educational system improves and people have fewer children.

• Phase 4 (Post- Industrial): Declining population growth because the relatively high level of affluence and economic develop encourage women to delay having children.

4.

5.

6. Using the demographic transition model, which stage would be characteristic of death rates falling while birth rates remain high?

a. Pre-industrial

b. Industrial

c. Post-industrial

d. Transitional

e. None of the above

7: In a human population undergoing

the demographic transition, which of

the following generally decreases

first?

a. Birth rate

b. Death rate

c. Avg. family size

d. Life expectancy

e. Level of education

Family Planning

• Family planning- the regulation of the number or spacing of offspring through the use of birth control.

What Is Family Planning?

Definition

Measures (tools) enabling parents to control the

number of children they have (if they so desire)

Goals of Family Planning

Not to limit births

For couples to have healthy children

For couples to be able to care for their children

For couples to have the number of children that they

want

The 12 Most Populous Countries in the World

The relationship between economic development and population growth rate for developing nations.

8. The number of children an average woman would have, assuming that she lives her full reproductive lifetime, is known as the –

a. Birth rate

b. Crude birth rate

c. TFR

d. RLF

e. Zero population growth

Ecological Footprints

• Affluence - having a lot of wealth such as money, goods, or property.

The wealth gap

• Residents of developed

nations have larger houses,

more possessions, and

more money than residents

of developing nations.

• The richest 20% of the

world’s people consumes

86% of its resources, and

has > 80 times the income

of the poorest 20%.

Three Most Populous

Countries• China- 1.3 Billion

• India- 1.2 Billion

• Positioned to surpass China by 2030

• More people living in India than the

entire western hemisphere

• US- 300 Million