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(1)

Lecture Outlines

Chapter 8

Human Population

(2)

This lecture will help you understand:

Human population growth

Different viewpoints on this growth

Population, affluence, and technology’s effects

Demography

Demographic transition

Factors affecting population growth

The HIV/AIDS epidemic

(3)
(4)

Central Case Study: China’s One-Child Policy

In 1970, China’s 790 million people were exhausting

their resources and faced starvation if growth continued

The government instituted a one-child policy

 The growth rate plummeted

 The policy is now less strict

The successful program has had unintended

consequences

 Killing of female infants and an imbalance in male to female ratios

(5)
(6)

Our World at Seven Billion

Populations continue to rise in most countries,

particularly in poverty-stricken developing nations

Growth in poorer nations leads to stresses on

society, the environment, and people’s well-being

China’s stringent policies have greatly slowed

growth there, but other countries may wish to slow

their growth without the measures used by China

 India’s growth continues and if not changed will surpass China’s population

(7)
(8)

The Population Explosion

The current world population is 7.732 Billion as of

September 25, 2019.

Each time your heart beats, three more people are

added to the world.

Each time a person dies 2.8 babies are born.

(9)

The human population is growing rapidly

Our population grows by over 70 million each year

It took until 1800 to reach 1 billion

In 1930 (130 years later) we reached 2 billion

We added the most recent billion in 12 years

Growth rates vary from country to country

Some countries are over 3%, while other country’s

populations are shrinking

The current world growth rate is 1.2%

At this rate, the human population of the planet would

(10)
(11)
(12)
(13)

Is population growth a problem?

Better technology, sanitation, medication, and

increased food supply have increased growth

Death rates drop, but not birth rates

Infant mortality rate = the death rate in children; has

dropped dramatically

Population growth was seen as good

Support for elderly, a larger labor pool

Thomas Malthus’s

An Essay on the Principles of

Population

(1798)

Humans will outstrip food supplies

(14)
(15)

Is population growth a problem?

 Neo-Malthusians: population growth will increase faster than food production; cause famine and conflict

 Paul Ehrlich’s Population Bomb (1968) predicted that civilization would end by the end of the 20th century

Intensified food production fed more people

 Cornucopians argue that we will continue to find new resources and technology to support people

Environmental scientists argue that there are finite

resources

 Land is limited, extinct species are gone forever

Quality of life will suffer with unchecked growth

(16)
(17)

Some national governments now fear falling

populations

Policymakers believe population growth increases

economic, political, and military strength

But growth is correlated with poverty, not wealth

Strong, rich nations have low growth ratesWeak, poor nations have high growth rates

Some nations offer incentives for more children

Elderly need social services

66% of European governments think their birth rate

is too low

49% of non-European nations feel their birth rates are

(18)

Population is one of several factors that affect

the environment

The

IPAT model

:

I

=

P

×

A

×

T

×

S

Total impact (

I

) on the environment results from:

Population (P) = individuals need space and

resources

Affluence (A) = greater per capita resource use

Technology (T) = increased exploitation of resources,

but also pollution controls and renewable energy

Sensitivity (S) = how sensitive an area is to human

pressure (e.g., arid land vs. rainforest)

(19)

Population is one of several factors that affect

the environment

Impact equates to pollution or resource consumption

Humans use 25% of Earth’s net primary production

Technology has increased efficiency and reduced

our strain on resources, resulting in further

population growth

For example, increased agricultural production

Modern China’s increasing affluence is causing:

Increased resource consumption

(20)

Modeling Population Growth—

(21)

Modeling Population Growth—

Human Population Growth and Regulation 1

(22)

Modeling Population Growth

(23)

Modeling Population Growth

(24)

Modeling Population Growth

(25)

Demography

Demography =

the application of population ecology

to the study of change in human populations

All population principles apply to humans

Environmental factors limit population growth

There is a carrying capacity for all species, including

humans

Humans raise the environment’s carrying capacity

through technology

How many humans can the world sustain?

(26)

Demography is the study of human population

Demographers

study:

Population size

Density and distributionAge structure

Sex ratio

Birth, death, immigration, and emigration rates

Population size

 Current world population is just over 7 billion

(27)

D. Changing Fertility Rates and the Demographic Transition

1. The gradual shift from the primitive to the modern condition that is correlated with development is called demographic transition.

2. Crude Birth Rate (CBR) is the number of births per 1000 individuals per year. Crude Death Rate (CDR) is the number of deaths per 1000

individuals per year. The term crude is used because there is no consideration for age or gender.

3. Subtracting the CDR from the CBR gives the increase or decrease per 1000 per year. Dividing this result by 10 then puts it in terms of per 100 or percent. We will call this number the percent

increase or decrease per year.

(28)

Calculating Fertility Rates and Doubling Times

(CBR - CDR)/10 = Rate of Increase or decrease

in population per 100 per year or growth

percentage rate

(29)
(30)
(31)
(32)
(33)

5. The Demographic transition has four phases.

a) Phase I is the primitive stability, with high

CBR’s and CDR’s.

b) Phase II is marked by a declining CDR that

results from improved infant mortality rates. There is a large population growth due to the fact that CBR’s do not go down. This phase is also know as Epidemiologic transition.

c) Phase III is a phase of declining CBR’s

resulting from a declining fertility rate. This phase is also known as Fertility transition.

d) Phase IV is reached, where modern stability

(34)
(35)

Phases of Demographic Transition

Phase I: primitive stability (CBR = CDR)

Phase II: declining CDR, CBR remains high

accelerating population growth

Phase III: declining fertility rate, but significant

population growth continues

(36)

Demographic Transition Comparisons (Figure

5-17)

Phase IV: developed countries

(37)
(38)

Population density and distribution

Population size alone does not tell whole story

People are not distributed equally over the planet

(clumped distribution)

Highest density: temperate, subtropical, tropical

biomes and close to water

 Cities are local high-density areas

Lowest density: away from water, extreme

environments

(39)
(40)

Age structure

Age structure describes the relative numbers in each

age class within a population

Age structure diagrams (population pyramids) show

age structure

Wide base denotes many young

High reproduction, rapid population growth

Even age distribution: remains stable as births keep

pace with deaths

(41)
(42)

Age structure

Many populations are getting older

Median global age today is 28, but it will be 38 by

2050

The elderly will need care and financial assistanceTaxes will increase for Social Security and MedicareBut fewer dependent children may mean lower crime

(43)

Age structure

China’s age structure is changing

In 1970, the median age was 20; by 2050 it will be 45

By 2050, over 300 million will be over 65

Fewer people will be working to support social

(44)
(45)
(46)

Sex ratios

 Unequal sex ratios can impact population growth

Human sex ratios at birth slightly favor males

 For every 100 females born, 106 males are born

 In China, 120 boys were reported for 100 girls

 Culture values males over females

 The government’s one-child policy

 Females have been selectively aborted

The undesirable social consequences?

 Many single Chinese men

(47)

Population change results from birth, death,

immigration, and emigration

Whether a population grows, shrinks, or remains

stable depends on rates of birth, death, and

migration

Birth and immigration add individuals

Death and emigration remove individuals

Technological advances caused decreased deaths

The increased gap between birth and death rates

(48)

Population change results from birth, death,

immigration, and emigration

Immigration/emigration have become more

important

War, civil strife, and environmental degradation cause

people to flee their homes

Each year, 25 million refugees escape poor

environmental conditions

This movement causes environmental problems

No incentives to conserve resources

(49)
(50)

Total fertility rate influences population growth

Total fertility rate

(TFR)

=

the average number of

children born to each female

Replacement fertility

=

the TFR that keeps the size

of a population stable (about 2.1)

TFR has been decreasing in many nations due to:

Industrialization

Improved women’s rightsQuality health care

In Europe as a whole, TFR is now 1.6

(51)
(52)
(53)

Many nations are experiencing the

demographic transition

In countries with good sanitation, health care, and

food, people live longer

Life expectancy

=

average number of years that an

individual is likely to continue to live

Has increased with reduced rates of infant mortality

Demographic transition

=

a model of economic

and cultural change

Explains the declining death and birth rates in

industrializing nations

(54)

Many nations are experiencing the

demographic transition

Pre-industrial stage

=

in pre-industrial societies,

both birth and death rates are high

High birth rate to compensate for high infant mortalityPopulation growth is slow

Transitional stage

=

declining death rates due to

increased food production and medical care

Birth rates remain high since people are not used to

the low infant mortality rates

(55)

Modeling Population Growth—

Human Population Growth and Regulation 4

(56)

Many nations are experiencing the

demographic transition

Industrial stage

=

birth rates fall as jobs provide

opportunities for women outside the home and

children are not needed in the workforce

Difference between birth and death rates shrinksPopulation growth slows

Post-industrial stage

=

birth and death rates are

low and stable

(57)
(58)
(59)

Demographic information

1. HDC, High income type country, like Canada, Western Europe, and the United States.

2. MDC, Middle income countries, like Latin America, parts of Asia, and parts of Africa. 3. LDC, Low income countries, like China,

central Africa, central Asia.

4. The disparity in distribution of wealth among

countries of the world is large. HDC’s have 18.8% of

the population and 80% of the world’s wealth. The

MDC’s and LDC’s combined have 81.2% of the world’s

(60)

Average Number of Children, Grandchildren,

and Great Grandchildren

America

West Germany

Africa

14

5

(61)

Major Economic Divisions of the World

(62)

Is the demographic transition a universal

process?

It has occurred in Europe, the U.S., Canada, Japan,

and other nations over the past 200–300 years

But it may or may not apply to developing nations

The transition could fail in cultures that:

Place greater value on childbirthGrant women fewer freedoms

For people to attain the material standard of living of North Americans, we would need the natural

(63)

Population and Society

Many factors affect fertility in a given society:

Access to family planningRates of infant mortalityLevels of women’s rightsLevel of affluence

Importance of child labor

(64)

Family planning is a key approach for

controlling growth

Family planning

=

efforts to control the number and

spacing of children; the greatest single factor

slowing population growth

Clinics offer advice, information, and contraceptives

Birth control

=

effort to control the number of

children born by reducing the frequency of

pregnancy

Contraception = deliberate prevention of pregnancy

through a variety of methods

(65)

Family planning is a key approach for

controlling growth

Low use of family planning may have different

causes

Rural areas may have limited availability

Religious doctrines or cultural influences may reject

family planning

Family planning gives women control over their

reproductive window

=

time frame where a woman

can become pregnant

Potential to produce 25 children during the windowFamily planning may delay first reproduction, space

(66)
(67)

Family-planning programs are working around

the world

Funding and policies that encourage family planning

lower population growth rates in all nations,

regardless of level of industrialization

Thailand’s educational-based approach to family

planning reduced its growth rate from 2.3% to 0.5%

Brazil, Mexico, Iran, Cuba, and other developing

countries have active programs

These entail setting targets and providing incentives,

(68)
(69)

Empowering women reduces fertility rates

Where women are freer to decide whether and when

to have children, fertility rates fall, and children are

better cared for, healthier, and better educated.

Fertility rates drop most noticeably when women

gain access to contraceptives and family-planning

programs

As women receive educational opportunities, fertility

rates decline

Two-thirds of the world’s illiterate are women

Education leads to delayed childbirth as women

(70)
(71)

Increasing affluence lowers fertility

Poorer societies have higher population growth rates

Consistent with the demographic transition theoryHigh fertility to ensure some children would survive

and be able to contribute to farm labor

More affluent societies can provide:

Better medical care, reducing infant mortality

Education for children (removing them from the

workforce and making them an economic liability)

Social security for the elderly

(72)
(73)

Increasing affluence lowers fertility

Poverty exacerbates population growth; population

growth exacerbates poverty

In 1960, 70% of all people lived in developing

nations

As of 2010, 82% live in these nations

99% of the next billion will be born in these nations

Population growth in poor nations increases

environmental degradation

Farming degrades soil in arid areas (Africa, China)

Poor people cut forests, deplete biodiversity, and hunt

(74)
(75)

Expanding wealth can increase the

environmental impact per person

Affluent societies have enormous resource

consumption and waste production

People use resources from other areas, as well as

from their own

Ecological footprints are huge

People in affluent societies have larger ecological

footprints

One American has as much environmental impact as

3.8 Chinese or 8 Indians or 14 Afghans

(76)

Expanding wealth can increase the

environmental impact per person

Biocapacity

=

the amount of biologically productive

land and sea available to us

Ecological deficit = ecological footprint > biocapacityEcological reserve = ecological footprint < biocapacity

We are running a global ecological deficit

Humanity’s global ecological footprint exceeds

biocapacity by 50%

(77)
(78)

HIV/AIDS is exerting major impacts on African

populations

The AIDS epidemic is having the greatest impact

since the Black Death in the 14th century

Of 34 million infected, two-thirds live in sub-Saharan

Africa; 3800 die/day

Low rates of contraceptive use spread the disease

Infant mortality is 14 times that of the developed worldLife expectancy has dropped from 60 years in the

1990s to 40–50 years today

(79)
(80)

Demographic change has social and economic

repercussions

AIDS undermines the ability of poor nations to

develop

Removes productive members of societyCost of medical treatment is a huge burden

(81)

Demographic change has social and economic

repercussions

Demographic fatigue

=

occurs when governments

face overwhelming challenges related to population

growth

With the added stress of HIV/AIDS, governments are

stretched beyond their capabilities

Problems grow worse and citizens lose faith

(82)

Population goals support sustainable

development

1994 UN conference on population and development

Rejected top-down, command-and-control approaches

that pushed contraceptives and preset targets

Urged education and health care

 Urged addressing social needs (like poverty, sexism) from the bottom up

To generate a high quality of life for all people,

developing nations must slow population growth

(83)

Factors Influencing Family Size

• Old age security

• Infant and childhood mortality rates

• Children: an economic asset or liability

• Importance of education

• Status of women

(84)

I Reassessing the Demographic Transition A. Factors Influencing Family Size

1. Security in one’s old age: In many LDC’s the only way that the old are taken care of is by

their families. In the HDC’s we have nursing homes and Social Security. This is one of the reasons they have many children, so

(85)

2. Infant and Childhood Mortality: The common and often personal experience of children dying leads people to desire additional children as an “insurance policy” for security in

their old age.

3. Helping hands : In the agriculture setting children can do work at a young age and will help

support

the family. In an industrial setting, the children

are more of a luxury, in that they cost more money than they bring in.

4. Importance of Education: When people go

through more education they will put off having children and thus they will have less reproductive

years. In addition, when children go to school they can not do the amount of work they

(86)

5. Status of Women: opportunities for women’s education and careers. : In

the LDC’s most women are thought of as only important for the number of children they can have. It is shown that the women

that have an eighth grade education have half the number of children as their

counterparts. 6. Availability of Contraceptives-

Contraceptives are available in the

industrialized world and not very available in the LDC’s. More than any other single

factor, lower fertility rates are correlated with the percent of the population using

(87)

TFR vs GNI PPP per capita,2004

8

7 Uganda

Congo•

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•Sudan

Kenya

•Pakis1an

ondt.Jras

hana

Banglade s Moilgoll

nd m

ndon•esl

a

7 e l o ping Countries ( China)

•Philippine

s

•Egypt . s Salvado

r

•Moroe<::o Por

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Figure 6·4 Emirooment.aiSdence.lO/e

02008Pt!arson Pfentk eHalt In<..

$4,000 £6,000 $8,000 $10,00

0 S120,00

(88)

Contraceptive prevalence and fertility rates, selected countrie&,2005

8

7

6

2

,

U.S.A

. • M ali •u ganda • • • Pakistan •••

libya •

•Kenya .

• G u a l e m a Oeveloptng Coonlries (

-China)

- •Honduras

• • ••

Mala• ysta. 1 n d. Bangladesh• Ecuador Mexico

Ja

•• • • • Tu.l'key • •

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•Brazil

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0o----10 ----m ---- ---- ----w

--ro-- r-o --- ro

----w----100

Percent using modern contraceptives

F;gure 6·6 Etwironmen.tal Science_ 10/t!

(89)
(90)

Conclusion

The human population is larger than at any other timeRates are decreasing but populations are still risingMost developed nations have passed through the

demographic transition

Expanding women’s rights slows population growthHow will the population stop rising?

 The demographic transition, governmental intervention, or disease and social conflict?

Sustainability requires a stabilized population to avoid

(91)

QUESTION: Review

What has accounted for most of the world’s population

growth in recent years?

a) Women are having more babies.

b) Technology, medicine, and food have decreased death rates.

c) Fewer women are using contraceptives.

(92)

QUESTION: Review

According to the

I

=

P

A

T

S

formula, what would

happen if China’s 1 billion people had a lifestyle like

that of Americans?

a) Their population would automatically drop.

(93)

QUESTION: Review

Where is the highest

density

of people found?

a) In the colder climates (e.g., Siberia)

b) In temperate or tropical biomes c) In rural areas

(94)

QUESTION: Review

An age structure diagram shaped like a pyramid with a

wide base shows a/an ________ population.

a) increasing b) decreasing c) stable

(95)

QUESTION: Review

Describe the relationship between population growth

rates

and population

size

.

a) Falling growth rates automatically mean a smaller population.

b) Falling growth rates automatically mean a larger population.

c) Falling growth rates mean we no longer have a population problem.

d) Falling growth rates do not mean a smaller

(96)

QUESTION: Review

Pre-industrial societies tend to have higher growth

rates because

a) good medical care prevents infant mortality. b) there is little opportunity for women to get an

education or employment.

c) governments provide social support networks for the elderly.

(97)

QUESTION: Weighing the Issues

Should the United States fund international family-

planning efforts?

a) Yes, absolutely.

b) Yes, but only in nations that follow U.S.-approved programs.

c) Only if it can influence the nations’ policies.

(98)

QUESTION: Weighing the Issues

Would you rather live in a country with a larger

population or smaller population?

a) Small population, so there will be more resources for me

b) Small population, so there will be more resources for others, including wildlife

c) Large population, so I can find a date

(99)

QUESTION: Interpreting Graphs and Data

What happens during the “transitional” stage of the

demographic transition?

a) High birth and death rates rise—population increases

b) High birth and death rates—population is stable c) High birth rates with

low death rates—

population increases d) Low birth and death

rates cause—

(100)

QUESTION: Interpreting Graphs and Data

According to this age pyramid, Nigeria’s future

population will be

a) balanced. b) larger.

c) much larger. d) smaller.

(101)

QUESTION: Interpreting Graphs and Data

According to these graphs, which countries had

access to family planning?

a) Iraq and Pakistan c) Malawi and

Kenya

b) Malawi and Haiti d) Kenya and

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