Our numbers expand, but Earth’s natural

systems do not

Lester R. Brown

The Human Population and its Impact

Unit 8

Human Population Growth

Reflects change from agrarian to industrial culture

Continues to grow exponentially at rate of

(≈227,000 people/day) Growth is unevenly distributed

across globe

3 Factors for Human Population Growth

Ability to expand into almost all climate zones, habitats

Ability to grow more food per unit of land

Drop in death rates due to improved sanitation, medicines

Cultural Carrying Capacity

Maximum number of people living comfortable and sustainably

Factors Affecting Human Population Size

Births Deaths Migration

Population Change =

(births + immigration) – (deaths + emigration)

Crude Birth Rate (CBR) number of live births per 1000 people in

a population in a given year

Crude Death Rate (CDR) Number of deaths per 1000 people in a

population in a given year

Demographic Quantities

Crude BirthRate CBR

Crude Death Rate CDR

World

All developedcountries

All developingcountries

Developingcountries

(w/o China)

21

9

1110

248

299

Africa

LatinAmerica

Asia

Oceania

UnitedStates

NorthAmerica

Europe

38

14

23

6

20

7

18

7

15

9

14

9

10

11

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CDR

Demographic Quantities

Zero Population Growth (ZPG) births + immigration = deaths + emigration

Rate of the World’s Annual Population Change

Annual rate of population change (%)

Birth Rate – Death Rate

1000X 100

Birth Rate – Death rate

10

or…

Developing vs Developed Countries

China and India- 37% of global population

US- 4.5% of global populationDeveloping countries > 95%

growth between 1998-2025

<1%

1-1.9%2-2.9%

3+%Data notavailable

WorldPopulation Growth

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Bro

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/Co

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Th

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son

Lea

rnin

gChina

India

USA

Indonesia

Brazil

Pakistan

Russia

Bangladesh

Japan

Nigeria

2002 2025

1.28 billion1.5 billion

1 billion1.4 billion

288 million

346 million

217 million282 million

174 million

219 million

144 million

242 million

144 million129 million

134 million

178 million

127 million

121 million

130 million205 million

The worlds 10 most populous countries (2002)

37%

4.6%

CHINA

INDIA

BANGLADESHTHAILAND

INDONESIA

JAPAN

PACIFICOCEAN

PHILIPPINES

NEWGUINEA

BORNEO

INDIAN OCEAN

SRI LANKA

NEPAL

PAKISTAN

Beijing

Shanghai

Hong Kong

Tibet

Delhi

CalcuttaBhopal

Bombay

State ofKerala

Bangkok

Where are they?

Global Fertility Rates

2 types: Replacement Level Fertility: number of

children to replace reproductive couple -2.1 in developed countries -2.5 in developing countries -population momentum: future increase

in population due to large number of people entering into childbearing years (despite those couple having few children)

Global Fertility Rates (cont’d)

Total Fertility Rate (TFR): estimate of average number of

children a woman will have in her lifetime -most useful measure for projecting

future population growth

TFR Facts

2000: TFR= 2.9* Highest TFR: Africa= 5.3 TFR= 2.3; world population= 8

billion in 2025 *if TFR remained at 2.9, human

population would reach 694 billion by 2150

World

Developedcountries

Developingcountries

Africa

LatinAmerica

Asia

Oceania

NorthAmerica

Europe

5 children per women

2.8

2.5

1.6

6.53.1

6.6

5.2

5.9

2.7

5.9

2.6

3.8

2.5

3.5

2.1

2.6

1.4

1950 2002

© 2

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There has been a

decline in total

fertility rates.

High

Medium

Low

12

11

10

9

8

7

6

5

4

3

21950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

High10.9

Medium9.3

Low7.3

Year

Po

pu

lati

on

(b

illi

on

s)Population Projections

Case Study: U.S. Population 2012- 310 mil (US pop in 1900 was 79 mil; took 139 yrs to add first 100 mil; 52 yrs to add next 100 mil; 39 yrs to add 3rd 100 mil) TFR= 2.1 Has highest fertility rate and highest

immigration rate of any industrialized country

(rate of growth has declined, but population is still growing faster than developed countries and China)

U.S. Population Growth

1.66 million more births than deaths

800,000- 1,000,000 legal immigrants

-53% from Latin America -25% from Asia -14% from Europe 300,000 illegal immigrants (est

11 million) Projected growth by 2050: 41%

to 86% (Pacific NW growth is higher than

India!)

32

30

2826242220181614

0

Bir

ths

per

th

ou

san

d p

op

ula

tio

n

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Year

Demographictransition Depression

End of World War II

Baby Boom Baby bust Echo Baby Boom

Birth Rates in the U.S.

United States Mexico Canada

Population(2002)

Projected population(2025)

346 million

Infant Mortality Rate

Lifeexpectancy

Total FertilityRate (TFR)

% populationunder age 15

% populationover age 65

Per CapitaGNI PPP

288 million102 million

31 million

132 million36 million

6.625

5.3

2.12.9

1.5

21%33%

19%

13%

13%5%

$8,790

77 years75 years

79 years

$34,110

$27,170

© 2004 Brooks/Cole – Thomson Learning

Comparison of Basic

Demographic Data

Reasons for Projected U.S. Growth

Large numbers of baby boom woman still in child-bearing years

Increase in number of unmarried mothers

High levels of immigrants Inadequate family-planning

services

Factors Affecting Total Fertility Rates

Importance of children in workforce (developing countries)

Cost of raising and educating children (developed countries)

Pension systems (reduces parents’ need for child support in their old age)

Factors Affecting Total Fertility Rates (cont’d)

Urbanization (better access to family planning )

Educational, employment opportunities for women (more education-fewer children)

Average age at which woman has first child

Religious beliefs, traditions, and cultural norms

Factors Affecting Death Rates

(also responsible for increased growth rates)

Increased food supply Better nutrition Medical advances in

immunizations, antibiotics Improved sanitation, cleaner

water(“It’s not that people stopped breeding

like rabbits, it’s just that they stopped dying like flies” UN)

Developed Countries

50

40

30

20

10

01775 1800 1850 1900 1950 2000 2050

Ra

te p

er

1,0

00

pe

opl

e

Year

Rate ofnatural increase

CrudeBirth Rate

CrudeDeath Rate

Rate of natural increase = Crude Birth Rate –Crude Death Rate

© 2004 B

rooks/Cole – T

homson Learning

Developing Countries50

40

30

20

10

01775 1800 1850 1900 1950 2000 2050

Ra

te p

er

1,0

00

Pe

op

le

CrudeBirth Rate

Rate of natural increase

CrudeDeath Rate

Year

© 2004 B

rooks/Cole – T

homson Learning

Rate of natural increase = Crude Birth Rate – Crude Death Rate

Indicators of Overall Health of a Country

1. Life expectancy: years a newborn infant can

expect to live -77 years (developed countries) -64 years (developing countries-

without AIDS, war) -globally: 48 yrs (1955), 66 yrs

(1998), 73 yrs (2025) -Africa: less than 50 yrs

Indicators of Overall Health of a Country (cont’d)

2. Infant mortality rate: # of babies/1000 that die before their 1st birthday

-best measure of society’s quality of life

-reflects level of nutrition (undernutrition, malnutrition), health care

(4 million infants die each year of preventable

causes)

<1010-3536-70

100+Data notavailable

Infant deaths per 1,000 live births

71-100

Infant Mortality Rates in 2002

Reasons for U.S. Infant Mortality

Inadequate health care for poor women

Drug addiction among pregnant women

High birth rate among teenage women

-US has highest teenage pregnancy rate in world

-babies born to teenagers is low (most

important factor in infant deaths)

Population Age Structure

Age structure diagrams: proportion of the

population at each age level 3 main age categories: -prereproductive: 0-14 -reproductive: 15-44 -postreproductive: 45+ Age distribution has long-lasting

economic and social impacts

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

Rapid GrowthGuatemala

NigeriaSaudi Arabia

Slow GrowthUnited States

AustraliaCanada

Male Female

Zero GrowthSpain

AustriaGreece

Negative GrowthGermanyBulgariaSweden

Population Age Structure

How Does Age Structure Affect Population Growth?

Rapid growth: wide base of preproductive age (0-14)

2010: 27% of global population was under 15 (1 in 4 on planet)

-30% in developing countries -16% in developed countries -44% in Africa

Case Study: American Baby Boom/Bust

1946-1964: 79 million people were added to U.S.:

-dominated demand for goods, services -decides who is elected to office -decides what laws are passed -seniors (65 ↑) fastest growing age group (“Graying

of America”)

-will pass on higher unemployment, taxes to millennial generation (born since 1980 AKA you guys)

194541.9 workers40

30

20

10

0

195016.5

20751.9

1945 2000 2050 2075

Nu

mb

er

of

Wo

rke

rs S

up

po

rtin

ge

ach

So

cia

l Se

curi

ty B

ene

fici

ary

Year

To maintain current ratio of workers to retirees,US will need to absorb 10.8immigrants each year through2050

Population Decline

Gradual decline: negative effects are manageable

Rapid decline: -threaten economic growth -labor shortages (health-care

workers) -budget strains on pension

plans, health- care costs ex. Japan, Russia, Germany, Italy,

Greece, Portugal

40

35

30

25

20

15

10

5

01950 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

Rapid population decline can lead to severe economic and social problems.

Case Study: The Graying of Japan

1949: TFR of 4.5 1998: TFR of 1.4 -resists increased immigration

(fear of social cohesiveness) -must depend on automation and women working outside of home

Population Decline and AIDS

1981-2009: 27 million people died of AIDS/ 2 million every year (WHO)

-22,000 in US; 39,000 in China; 350,000 Africa

-results in loss of productive workers -drastically alters age structure -creates large number of orphans

The Environment and Population

1995: 27 million international refugees moved due to environment degradation (drought, desertification, deforestation, soil erosion, resource shortages)

1988-1998: 50 million left homeless due to natural disasters (earthquakes, hurricanes, floods, landslides)

US, Australia, Canada accept large #’s of refugees

Why Slow Population Growth?: Opposing Views

Asking the wrong question What is the earth’s

optimum sustainable population?

Earth is not over-

populated. Longer life span

today proof of capability to sustain greater population

Population regulation is a violation of personal freedom Should be able to

have as many children as we want.

Cannot provide basic necessities for everyone today Raising the death

rates for humans Increasing

environmental harm

FYI: For Your Consideration

Some computer models suggest that the Earth could support 20-48 billion people if everyone existed at a survival level:

-grain-only diet -cultivate all arable land -mine the Earth’s crust to a depth of a mile

Some scientists suggest that the key factor isn’t overpopulation, but overconsumption: affluence leading to over-consumption of resources per person

How to Slow Population Growth

Reduce poverty by promoting economic development

Elevate the status of womenEncourage family planning

Economic Development Occurs in Stages

Demographic transition: hypothesis of population change as countries become more industrialized:

1) death rates drop 2) birth rates decline

Demographic Transition

1. Pre-industrial stage: harsh living conditions, high infant mortality and death rates; population growth is small (if at all)

2. Transitional stage: start of industrialization, ↑ food production, ↓ death rate; pop. growth is

rapid- China, India3. Industrialized stage: birth rates↓, ↑ access to

birth control, reduced infant mortality, higher cost of raising children; pop. growth

slows 4. Post-industrial: further decline in birth rate,

ZPG -37 countries, including western Europe, Japan

Low

High

Rel

ativ

e p

op

ula

tio

n s

ize

Bir

th r

ate

and

dea

th r

ate

(nu

mb

er p

er 1

,000

per

yea

r) 80

70

60

50

40

30

20

10

0

Stage 1Preindustrial

Stage 2Transitional

Stage 3Industrial

Stage 4Postindustrial

Lowgrowth rate

Increasing growth rate

Very highgrowth rate

Decreasinggrowth

rate

Lowgrowth rate

Zerogrowth

rate

Negativegrowth

rate

Birth rate

Total population

Death rate

Time

Demographic Transition (cont’d)

Developing countries: transitional stage

-pop growth outstrips economic growth (demographic trap)

-lack skilled workers to produce high-tech products -lack capital, resources for

economic development

Elevating the Status of Women Females make up ½ of global pop, but have

fewer opportunities for education (economic opportunities)

Females do most of the world’s domestic work (growing food, hauling wood and water), child care, and health care (unpaid)

Benefits of educating females: -ability to control fertility (tend to have

fewer children) -earn an income -societies that do not suppress women

4:45 A.M.Wake,wash, andeat

5:00 A.M.-5:30 A.M.Walk tofields

3:00 P.M.-4:00 P.M.Collectfirewood

4:00 P.M.-5:30 P.M.Pound andgrind corn

5:30 AM.-3:00 P.M.Work infields

5:30 P.M.-6:30 P.M.Collectwater

6:30 P.M.-8:30 P.M.Cook forfamily andeat

8:30 P.M.-9:30 P.M.Washdishesand children

9:30 P.M.Go to bed

Typical Workday for a Woman in Africa

Promoting Family PlanningMajor factor in reducing birth rateReduced # of abortionsReduced # mother and fetus deaths (600,000 women die from pregnancy-

related causes)Drop in TFR by ≈ 55% in developing

countries (6 in 1960 to 3.2 in 2000) Financial benefit: each dollar spent in

developing countries saves $10-$16 in social services

Use of Rewards and Penalties in Reducing Births

Penalties (China): higher taxes, eliminating tax deductions for third child, loss of health benefits and food allotments

Rewards: reinforcement of trends toward smaller families (social acceptance), increasing a poor family’s economic status

India’s Failed Family Planning Program

Bureaucratic inefficiency.Low status of women.Extreme poverty.Lack of administrative financial

support. Disagreement over the best ways to

slow population growth.

China’s Family Planning Program Currently, China’s TFR is 1.6 children

per women. China has moved 300 million people

out of poverty. Problems:

-Strong male preference leads to gender

imbalance (by 2030, 30 million males will not be

able to find brides)-Average population age is increasing without

children to support elders

The Rule of 70

Used to estimate doubling time of any population growing exponentially

Formula: Doubling time (yrs) = 70 %

growth rate

Rule of 70 Example

in 2010, the population of Upper Fremont is 200,000 and growing at a rate of 2% each year. (a) If the rate of growth remains constant,

calculate the population in 2045 -doubling time = 70 = 35 yrs 2 -2045-2010 = 35 yrs - answer: 400,000 What will the population be in 2080?

Chapter 6, 22 Human Population Exam Focus

3 factors for exponential pop growth Definition of cultural carrying capacity 3 main factors affecting pop. Size (know the

equation) ZPG (what it stands for and know the equation) TFR (what it stands for and what it means) CBR; CDR (know formula) Replacement Level Fertility 4 stages of demographic transition Most useful indicators of overall health of a

population

Human Population Exam Focus Population momentum Relative growth rates of developed vs

developing countries Cases of India and China (why hasn’t India’s

family planning been successful?; results of China’s population control)

Reasons for infant mortality in US Predicted outcome of “Boomer” generation

reaching 65 Age structure graphs and examples of each Ways to slow population growth Key factors that women to have fewer children Family planning Affect of AIDS on global population