Human Populations:

Population Dynamics IB syllabus: 3.1.1-3.1.4

Ch 12

Video: The Population Paradox – World in the Balance

Guru

Topic

3

H

um

an P

opula

tion

1

Syllabus Statements

• 3.1.1: Describe the nature and explain the implications of exponential growth in human populations

• 3.1.2: Calculate and explain, from given data, the values of crude birth rate, crude death rate, fertility , doubling time and natural increase rate

• 3.1.3: Analyze age/sex pyramids and diagrams showing demographic transition models

• 3.1.4: Discuss the use of models in predicting the growth of human populations

Guru

Topic

3

H

um

an P

opula

tion

2

vocabulary

1. Crude birth rate

2. Crude death rate

3. Demographic transition

4. Doubling time

5. Fertility

6. Rate of natural increase

Guru

Topic

3

H

um

an P

opula

tion

3

Factors Effecting Population Size

• 3 factors effecting population birth, death, & migration.

• Population change = (Birth + Immigration) – (Deaths + Emigration)

• Rates more often used.

• Crude Birth rate = # live births / 1000 people in year population.

• Crude Death rate = # deaths / 1000 people in year population

Guru

Topic

3

H

um

an P

opula

tion

4

Average crude birth rate Average crude death rate

World

All developed

countries

All developing

countries

Developing

countries

(w/o China)

21

9

11

10

24

8

29

9

© 2004 Brooks/Cole – Thomson Learning

Guru

Topic

3

H

um

an P

opula

tion

5

Africa

Latin

America

Asia

Oceania

United

States

North

America

Europe

38

14

23

6

20

7

18

7

15

9

14

9

10

11

© 2

00

4 B

roo

ks

/Co

le –

Th

om

so

n L

ea

rnin

g

Guru

Topic

3

H

um

an P

opula

tion

6

World Population Change

• Worldwide birth and death rates dropping

• Death rate dropping faster than birth rate

• 216,000 people added to world population daily

• Exponential population growth still occurring but slower

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

Population counter

• But base number still increasing

• 79 x 106 people added per year

Guru

Topic

3

H

um

an P

opula

tion

7

World Population over the Centuries

9,000 human beings added to the

planet every hour

Guru

Topic

3

H

um

an P

opula

tion

8

<1%

1-1.9%

2-2.9%

3+%

Data not available

Annual world population growth

Guru

Topic

3

H

um

an P

opula

tion

9

Reasons for the Human Population Explosion

• Death rates dropping faster

because of

• Causes of disease

recognized

• Improvements in nutrition

• Discovery of antibiotics

• Improvements in medicine

• Increase in number of

women who actually reach

child-bearing age

Age Birth Death

A

B

Survival changed from B to A

Guru

Topic

3

H

um

an P

opula

tion

10

Implications of Exponential Growth

• Biotic potential exceeds environmental resistance: birth

rates exceed death rates

• Outstrip our resource base – nonrenewable gone,

renewable maybe used faster than replaced

• Increase strain on the environment – pollution,

sanitation needs, biodiversity loss

• Increase food production & land under production

Guru

Topic

3

H

um

an P

opula

tion

11

Guru

Topic

3

H

um

an P

opula

tion

12

Average Number of Children, Grandchildren, and Great Grandchildren

• America

• West Germany

• Africa

• 14

• 5

• 258

Guru

Topic

3

H

um

an P

opula

tion

13

Fertility • Replacement fertility – number of children a

couple must bear to replace themselves – roughly

2.1

• Reaching replacement fertility now would still

cause population growth for another 50 years

• Total fertility rate (TFR)= # of children a woman

will have in her childbearing years (15-49)

• TFR = 1.6 in developed countries, 3.1 in

developing countries

Guru

Topic

3

H

um

an P

opula

tion

14

Calculating Fertility Rates and Doubling Times

(CBR – CDR)/10 = Rate of increase or decrease

in population per 1,000 per year

70/Rate of Increase = Doubling Time

Guru

Topic

3

H

um

an P

opula

tion

15

Calculating Fertility Rates and Doubling Times: Practice

Country CBR CDR Rate of

Increase

Doubling

Time

Kenya 33 13

Mexico 27 5

USA 15 9

Denmark 13 11

Guru

Topic

3

H

um

an P

opula

tion

16

Calculating Fertility Rates and Doubling Times: Answers

Country CBR CDR Rate of

Increase

Doubling

Time

Kenya 33 13 2.0 35

Mexico 27 5 2.2 32

USA 15 9 0.6 116

Denmark 13 11 0.2 431

350

Guru

Topic

3

H

um

an P

opula

tion

17

Births per woman

< 2

2-2.9

3-3.9

4-4.9

5+

Data not

available

Worldwide TFR in 2002

Guru

Topic

3

H

um

an P

opula

tion

18

High

Medium

Low

12

11

10

9

8

7

6

5

4

3

2 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

High

10.9

Medium

9.3

Low

7.3

Year

Po

pu

lati

on

(b

illi

on

s)

Population projections based on TFR (H = 2.6, M = 2.1, L = 1.7)

Guru

Topic

3

H

um

an P

opula

tion

19

4.0

3.5

3.0

2.5

2.0 2.1

1.5

1.0

0.5

0 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Year

Bir

ths p

er

wo

man

Baby boom

(1946-64)

US fertility and the “baby boom”

32 30 28 26 24 22 20 18 16 14 0

Bir

ths

pe

r th

ou

sa

nd

po

pu

lati

on

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Year

Demographic

transition Depression

End of World War II

Baby boom Baby bust Echo baby boom

Guru

Topic

3

H

um

an P

opula

tion

20

Factors effecting Birth & TFR 1. Importance of children for

labor higher in developing countries & rural areas

2. Urbanization more family planning resources, less need for children in cities

3. Cost of raising or educating children more expensive to raise in developed areas

4. Education & Employment for women less opportunity outside of house higher TFR

5. Infant mortality rate When infant mortality lower fewer children needed

6. Average age at marriage Fewer children when 25 or older for marriage

7. Availability of pension Eliminate need for kids to take care of you

8. Availability of Legal abortion

9. Availability of & Reliability of birth Control

10.Religious beliefs, traditions, cultural norms

Guru

Topic

3

H

um

an P

opula

tion

21

Life & Death • Infant mortality and Life Expectancy are good

indicators of health in a country

• Global life expectancy is increasing

• Poorest countries it may still be low or even falling (AIDS in Africa)

• Infant mortality encompasses nutrition & health care so it’s a good measure

• Still 8 million infants worldwide dieing of preventable causes in first year of life

• US – teen pregnancy rate highest of all industrialized countries

Guru

Topic

3

H

um

an P

opula

tion

22

Guru

Topic

3

H

um

an P

opula

tion

23

<10

10-35 36-70

100+

Data not available

Infant deaths per 1,000 live births

71-100

Guru

Topic

3

H

um

an P

opula

tion

24

Different Worlds

• Rich nations, poor nations

• Population growth in rich and poor nations

• Different populations, different problems

Guru

Topic

3

H

um

an P

opula

tion

25

Population (2002)

Population projected

(2025)

Infant mortality

rate

Life expectancy

Fertility rate (TFR)

%Population under

age 15

% Population over

age 65

Per capita GNI PPP

(2000)

288 million 174 million

130 million

346 million

219 million 205 million

6.8 33

75

77 years

69 years 52 years

2.1 2.2

5.8

21% 33%

44%

13%

5% 3%

$34,100

$7,300

$800

United States (highly developed)

Brazil (moderately developed)

Nigeria (less developed)

© 2004 Brooks/Cole – Thomson Learning

Guru

Topic

3

H

um

an P

opula

tion

26

Economic Categories Based on Per Capita Gross National Income

• High-income, highly developed, industrialized countries

• United States, Japan, Canada

• Average GNI per capita = $26,710

• Middle-income, moderately developed countries

• Latin America, South Africa, China

• Average GNI per capita = $1,850

• Low-income, developing countries

• Western and central Africa, India, central Asia

• Average GNI per capita = $430

Guru

Topic

3

H

um

an P

opula

tion

27

Disparities

• Developed countries

• 16% of the world’s population

• Control 81% of the world’s wealth

• Low-income developing countries

• 41% of the world’s population

• Control 3.4% of the world’s gross national income

• Difference in per capita income: 62 to 1!

Guru

Topic

3

H

um

an P

opula

tion

28

Population Increase in Developed and Developing Countries

Guru

Topic

3

H

um

an P

opula

tion

29

Developed Countries

50

40

30

20

10

0 1775 1800 1850 1900 1950 2000 2050

Rate

per

1,0

00 p

eo

ple

Year

Rate of

natural increase

Crude

birth rate

Crude

death rate

Rate of natural increase = crude birth rate – crude death rate

© 2

00

4 B

roo

ks

/Co

le –

Th

om

so

n L

ea

rnin

g

Guru

Topic

3

H

um

an P

opula

tion

30

Developing Countries

50

40

30

20

10

0 1775 1800 1850 1900 1950 2000 2050

Rate

per

1,0

00 p

eo

ple

Crude

birth rate

Rate of

natural

increase Crude

death rate

Year

© 2

00

4 B

roo

ks

/Co

le –

Th

om

so

n L

ea

rnin

g

Guru

Topic

3

H

um

an P

opula

tion

31

Population Age Structure

• Analysis by sex, of the proportion of population at each age level

• 3 main age categories • Prereproductive: 0 – 14 years

• Reproductive: 15 – 44 years

• Postreproductive: 45 and up

• Represent a good comparison between countries

• Compare Growth Rapid, Slow, Zero, Negative

Guru

Topic

3

H

um

an P

opula

tion

32

Male Female

Rapid Growth

Guatemala

Nigeria

Saudi Arabia

Slow Growth

United States

Australia

Canada

Male Female

Ages 0-14 Ages 15-44 Ages 45-85+

© 2004 Brooks/Cole – Thomson Learning

Guru

Topic

3

H

um

an P

opula

tion

33

Zero Growth

Spain

Austria

Greece

Negative Growth

Germany

Bulgaria

Sweden

Male Female Male Female

Ages 0-14 Ages 15-44 Ages 45-85+

© 2004 Brooks/Cole – Thomson Learning

Guru

Topic

3

H

um

an P

opula

tion

34

Age Structure & Population Growth

• Country with many people under 15 has large potential for population increase.

• Depends on the number of females as well

• In 2002 30% of world population was below 15 (33% in developing countries)

• Population has stabilized or declining in most developed countries

• Many developing countries expected to double or triple before stabilizing

• Mexico, Ethiopia, Nigeria, Pakistan, Brazil

Guru

Topic

3

H

um

an P

opula

tion

35

Population Momentum

• Countries like Iraq will continue to grow for 50–60 years even after the total fertility rate is reduced to replacement level.

Guru

Topic

3

H

um

an P

opula

tion

36

Projections of Population and Economics • Track the baby boomers through age pyramids

• Currently ½ of adult Americans

• Dominate demand for goods, services, & control politics and laws

• The social security problem – Paid for by current workers, fewer

than boomers

• Future impact = later retirement, more taxes, …

Guru

Topic

3

H

um

an P

opula

tion

37

20

Age

Females Males

1955

16 12 8 4 4 8 12 16

20

Millions

Age

24 20 16 12 8 4 4 8 12 16 20 24

Females Males

1985

Millions © 2004 Brooks/Cole – Thomson Learning

Age

Females Males

2015

20 16 12 8 4 4 8 12

16 20 20

Millions

Age

24 20 16 12 8 4 4 8 12 16 20 20

Females Males

2035

Millions

Guru

Topic

3

H

um

an P

opula

tion

38

1945

41.9 workers

40

30

20

10

0

1950

16.5

2075

1.9

1945 2000 2050 2075

Nu

mb

er

of

wo

rkers

su

pp

ort

ing

each

So

cia

l S

ecu

rity

ben

efi

cia

ry

Year

Guru

Topic

3

H

um

an P

opula

tion

39

Problems with Population decline

• If many populations stable now

• At some future time they will begin to decline

• By 2050 – 39 countries are expected to be in decline

• If rapid, can cause problems (1) consume public services,

health care, social security; (2) labor shortage, increased

reliance on immigrant labor

Guru

Topic

3

H

um

an P

opula

tion

40

40

35

30

25

20

15

10

5

0

1950 1970 1990 2010 2030 2050 2070 2090 2110 2130 2150

Year

Ag

e D

istr

ibu

tio

n (

%)

Under age 15 Age 60 or over Age 80 or over

Global

Aging

Guru

Topic

3

H

um

an P

opula

tion

41

Population decline from rising death rates

• HIV epidemic in Africa kills 6000 daily

• Kills mostly young adults

• Sharp decrease in average life expectancy

• Loss of productive workers

• Rise in numbers of orphans

• Drop in food production with loss of laborers

• Need new Marshall Plan

• Reduce HIV spread: education, health services

• Restore economic progress: aid as $ & volunteers

Guru

Topic

3

H

um

an P

opula

tion

42

Is the world overpopulated?

• Wrong question?

• What is the optimum number of people that can be

sustainably supported by the earth without further

environmental degradation

• Optimum would allow people to live comfortably without

harming future generations

Guru

Topic

3

H

um

an P

opula

tion

43

Solutions

1. Reducing births!

- Violation of personal and religious freedoms

- Viewed as a form of genocide by some ethnic groups

- BUT

- We currently don’t provide basic needs for 1/6 of the world population

- Increasing environmental harm & death rates

- Life span longer today so we have a greater per person impact too

Guru

Topic

3

H

um

an P

opula

tion

44

Demographic Transition Hypothesis • As countries become industrialized first death rate then birth rate

will decline

1. Preindustrial Stage harsh living conditions = little population

growth, high B & D

2. Transitional Stage industrialization starts, better healthcare &

food = population growth is rapid, high B & lower D

3. Industrial Stage Industry continues = population grows but

slowly, B > D by a little

4. Postindustrial Stage population growth stops, B = D (13% of

world) then B < D an may start to decline (this may be stage 5)

Guru

Topic

3

H

um

an P

opula

tion

45

Low

High

Re

lati

ve

po

pu

lati

on

siz

e

Bir

th r

ate

an

d d

ea

th r

ate

(n

um

be

r p

er

1,0

00

pe

r ye

ar)

80

70

60

50

40

30

20

10

0

Stage 1

Preindustrial

Stage 2

Transitional

Stage 3

Industrial

Stage 4

Postindustrial

Low growth rate

Increasing growth rate

Very high growth rate

Decreasing growth rate

Low growth rate

Zero growth rate

Negative growth rate

Birth rate

Total population

Death rate

Time

Guru

Topic

3

H

um

an P

opula

tion

46

Demographic Transition Comparisons

Guru

Topic

3

H

um

an P

opula

tion

47

Demographic Transition Hypothesis

• Most developing countries today have death rates declining

more than birth rates

• Still in Transitional stage

• Fear that population growth in these areas will overcome

economic growth

• Demographic Trap: get stuck in a stage

• Countries lack skilled workers, capital & resources, drop in

economic assistance

Guru

Topic

3

H

um

an P

opula

tion

48

Can we reduce Birth rates

• Doing so will reduce abortion rates & save lives as well

1. Family Planning – info on birth spacing, birth control and

prenatal care

2. Empowering women – education, job opportunities, womens

rights

• Women work 2/3 all hours worked, 10% income

3. Economic Rewards & Penalties – payments to individuals who

use contraceptives

Guru

Topic

3

H

um

an P

opula

tion

49

Condom

5%

Female sterilization

17%

IUD

12%

Other

methods

10%

Pill

8%

Male

sterilization

5%

No method

43%

Global

Contraceptive Use

Guru

Topic

3

H

um

an P

opula

tion

50

India: A Case Study • World’s first national family planning program

• After 50 years it is still the second most populous country in world

(1 billion)

• GNIPP is $2,340 a year

• Unemployment = 50%

• 40% population, 50% children suffer malnutrition

• 16% world population, 2% resources

• ½ cropland degraded, 70% water seriously polluted

• Overall, program disappointing & poorly done

Guru

Topic

3

H

um

an P

opula

tion

51

China: A Case Study • 1972-2002 cut crude birth rate in half, TFR from 5.7 to 1.8 children per

woman • Encourage late marriage & 1 child per family

• Contraception. Sterilization, Abortion = FREE

• Reward Food, $$$, School tuition, Medical care

• UN projects population drop by 2042

• It was either population control or starvation

• Population still growing, mass environmental impact

• But projected to be on the decline by 2040

Guru

Topic

3

H

um

an P

opula

tion

52

Percentage of world

population

Population (2000)

Population (2025) (estimated)

Illiteracy (%of adults)

Population under age 15(%)

Population growth rate (%)

Total fertility rate

Infant mortality rate

Life expectancy

GNP per capita (1998)

16%

21%

1 billion

1.3 billion

1.4 billion

1.4 billion

47%

17%

36%

25%

1.8%

0.9%

3.3 children per woman (down from 5.3 in 1970)

1.8 children per woman (down from 5.7 in 1972)

72

31

61 years

71 years

$440

$750

India

China

Guru

Topic

3

H

um

an P

opula

tion

53

Cutting Global Population Growth

• UN encouraging world population stability

• Universal access to family planning

• Improve health care – infants, children, women

• Social & Economic plans for countries

• Increase access to education

• Eradicate poverty

• Eliminate unsustainable patterns of production and consumption

Guru

Topic

3

H

um

an P

opula

tion

54

The use of Models

• We can’t see the future

• But we have good predictive power based on current numbers

• Using birth & death rates, fertility and extrapolation we can

model populations into the future

• Models based on mathematical calculations of future

predictions

Guru

Topic

3

H

um

an P

opula

tion

55

Computer Simulations

• View Population connection simulation

Guru

Topic

3

H

um

an P

opula

tion

56

Demographic Tables

• http://www.wpro.who.int/publications/databases/demographic_tables/en/

Guru

Topic

3

H

um

an P

opula

tion

57

Projecting Future Populations: Age/Sex Pyramids

Guru

Topic

3

H

um

an P

opula

tion

58

Graphical Extrapolation: World Population

Guru

Topic

3

H

um

an P

opula

tion

59

• http://www.shambles.net/worldclock/worldclock.swf

Guru

Topic

3

H

um

an P

opula

tion

60

Review Topics

Guru

Topic

3

H

um

an P

opula

tion

61

Are these characteristics of Developing or Developed Nations?

• High fertility rates

• High consumptive lifestyles: use 80% of world’s wealth

• Intense poverty

• Eat high on the food chain

• Long doubling times

• High environmental degradation

• Twenty percent of the world’s population

• Rule of 70 – yrs it takes for pop to double Guru

Topic

3

H

um

an P

opula

tion

62

Compare Projected Populations in Developing and Developed Countries

Fertility Rate

> 2

Fertility Rate

< 2

Guru

Topic

3

H

um

an P

opula

tion

63

Consequences of Exploding Populations

More Population

Causes MORE

LESS

deforestation

resource depletion

loss of agricultural land

disease

population migration

Irrigation

biodiversity

pest resistance

wetlands

Guru

Topic

3

H

um

an P

opula

tion

64