Human Populations:Human Populations:Population DynamicsPopulation Dynamics

IB syllabus: 3.1.1-3.1.4IB syllabus: 3.1.1-3.1.4Ch 12Ch 12

Video: Population connection videoVideo: Population connection video Population Paradox – world in the Population Paradox – world in the

balancebalance

Syllabus StatementsSyllabus Statements 3.1.1: Describe the nature and explain the 3.1.1: Describe the nature and explain the

implications of exponential growth in human implications of exponential growth in human populationspopulations

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

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

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

vocabularyvocabulary

Crude birth rateCrude birth rate

Crude death rateCrude death rate

Demographic transitionDemographic transition

Doubling timeDoubling time

FertilityFertility

Rate of natural increaseRate of natural increase

Factors Effecting Population SizeFactors Effecting Population Size

3 factors effecting population birth, 3 factors effecting population birth, death, & migrationdeath, & migration

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

Rates more often usedRates more often used Crude Birth rate = # live births / 1000 Crude Birth rate = # live births / 1000

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

people in year populationpeople in year population

Average crude birth rate Average crude death rate

World

All developedcountries

All developingcountries

Developingcountries

(w/o China)

21

9

11

10

24

8

29

9

© 2004 Brooks/Cole – Thomson Learning

Africa

LatinAmerica

Asia

Oceania

UnitedStates

NorthAmerica

Europe

38

14

23

6

20

7

18

7

15

9

14

9

10

11

© 2

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World Population ChangeWorld Population Change

Worldwide birth and death rates droppingWorldwide birth and death rates dropping Death rate dropping faster than birth rateDeath rate dropping faster than birth rate 216,000 people added to world population 216,000 people added to world population

dailydaily Exponential population growth still occurring Exponential population growth still occurring

but slowerbut slower http://www.census.gov/main/www/popclock.htm

l - Population counter - Population counter

But base number still increasingBut base number still increasing 79 x 1079 x 1066 people added per year people added per year

World Population over the CenturiesWorld Population over the Centuries

9,000 human beings added to the planet every hour

<1%

1-1.9%2-2.9%

3+%Data notavailable

Annual worldpopulation growth

Reasons for the Human Population ExplosionReasons for the Human Population Explosion

Death rates dropping Death rates dropping faster because offaster because of

Causes of disease Causes of disease recognizedrecognized

Improvements in Improvements in nutritionnutrition

Discovery of antibioticsDiscovery of antibiotics Improvements in Improvements in

medicinemedicine Increase in number of Increase in number of

women who actually women who actually reach child-bearing agereach child-bearing age

% S

urvi

val

AgeBirth Death

A

B

Survival changed from B to A

Implications of Exponential GrowthImplications of Exponential Growth

Biotic potential exceeds environmental Biotic potential exceeds environmental resistance: birth rates exceed death ratesresistance: birth rates exceed death rates

Outstrip our resource base – Outstrip our resource base – nonrenewable gone, renewable maybe nonrenewable gone, renewable maybe used faster than replacedused faster than replaced

Increase strain on the environment – Increase strain on the environment – pollution, sanitation needs, biodiversity pollution, sanitation needs, biodiversity lossloss

Increase food production & land under Increase food production & land under productionproduction

Average Number of Children, Average Number of Children, Grandchildren, and Great Grandchildren, and Great

GrandchildrenGrandchildren

AmericaAmerica West GermanyWest Germany AfricaAfrica

1414 55 258258

FertilityFertility

Replacement fertilityReplacement fertility – number of children a – number of children a couple must bear to replace themselves – couple must bear to replace themselves – roughly 2.1roughly 2.1

Reaching replacement fertility now would still Reaching replacement fertility now would still cause population growth for another 50 cause population growth for another 50 yearsyears

Total fertility rateTotal fertility rate (TFR)= # of children a (TFR)= # of children a woman will have in her childbearing years woman will have in her childbearing years (15-49)(15-49)

TFR = 1.6 in developed countries, 3.1 in TFR = 1.6 in developed countries, 3.1 in developing countriesdeveloping countries

Calculating Fertility Rates and Calculating Fertility Rates and Doubling TimesDoubling Times

(CBR – CDR)/10 = Rate of increase or decrease in population per 1,000 per year

70/Rate of Increase = Doubling Time

Calculating Fertility Rates and Calculating Fertility Rates and Doubling Times: PracticeDoubling Times: Practice

Country CBR CDR Rate of Increase

Doubling Time

Kenya 33 13

Mexico 27 5

USA 15 9

Denmark 13 11

Calculating Fertility Rates and Calculating Fertility Rates and Doubling Times: AnswersDoubling 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

Births per woman

< 2

2-2.9

3-3.9

4-4.9

5+

Data notavailable

Worldwide TFR in 2002

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

illio

ns)

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

4.0

3.5

3.0

2.5

2.02.1

1.5

1.0

0.5

01920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Year

Bir

ths

per

wo

man

Baby boom(1946-64)

US fertility and the “baby boom”

323028262422201816140

Bir

ths

pe

r th

ou

sa

nd

po

pu

lati

on

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

Factors effecting Birth & TFRFactors effecting Birth & TFR

1.1. Importance of children Importance of children for labor for labor higher in higher in developing countries & developing countries & rural areasrural areas

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

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

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

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

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

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

8.8. Availability of Legal Availability of Legal abortionabortion

9.9. Availability of & Reliability Availability of & Reliability of birth Controlof birth Control

10.10. Religious beliefs, Religious beliefs, traditions, cultural normstraditions, cultural norms

Life & DeathLife & Death Infant mortality and Life Expectancy are Infant mortality and Life Expectancy are

good indicators of health in a countrygood indicators of health in a country Global life expectancy is increasingGlobal life expectancy is increasing Poorest countries it may still be low or even Poorest countries it may still be low or even

falling (AIDS in Africa)falling (AIDS in Africa) Infant mortality encompasses nutrition & Infant mortality encompasses nutrition &

health care so it’s a good measurehealth care so it’s a good measure Still 8 million infants worldwide dieing of Still 8 million infants worldwide dieing of

preventable causes in first year of lifepreventable causes in first year of life US – teen pregnancy rate highest of all US – teen pregnancy rate highest of all

industrialized countriesindustrialized countries

<1010-3536-70

100+Data notavailable

Infant deaths per 1,000 live births

71-100

Different WorldsDifferent Worlds

Rich nations, poor nationsRich nations, poor nations Population growth in rich and poor Population growth in rich and poor

nationsnations Different populations, different problemsDifferent populations, different problems

Population(2002)

Populationprojected

(2025)

Infantmortality

rate

Lifeexpectancy

Fertilityrate (TFR)

%Populationunder

age 15

% Populationover

age 65

Per capitaGNI PPP

(2000)

288 million174 million

130 million

346 million219 million

205 million

6.833

75

77 years

69 years52 years

2.12.2

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

Economic Categories Based on Per Economic Categories Based on Per Capita Gross National IncomeCapita Gross National Income

High-income, highly developed, High-income, highly developed, industrialized countriesindustrialized countries United States, Japan, CanadaUnited States, Japan, Canada Average GNI per capita = $26,710Average GNI per capita = $26,710

Middle-income, moderately developed Middle-income, moderately developed countriescountries Latin America, South Africa, ChinaLatin America, South Africa, China Average GNI per capita = $1,850Average GNI per capita = $1,850

Low-income, developing countriesLow-income, developing countries Western and central Africa, India, central AsiaWestern and central Africa, India, central Asia Average GNI per capita = $430Average GNI per capita = $430

DisparitiesDisparities

Developed countriesDeveloped countries 16% of the world’s population16% of the world’s population Control 81% of the world’s wealthControl 81% of the world’s wealth

Low-income developing countriesLow-income developing countries 41% of the world’s population41% of the world’s population Control 3.4% of the world’s gross national Control 3.4% of the world’s gross national

incomeincome Difference in per capita income: 62 to Difference in per capita income: 62 to

1!1!

Population Increase in Developed Population Increase in Developed and Developing Countriesand Developing Countries

Developed Countries

50

40

30

20

10

01775 1800 1850 1900 1950 2000 2050

Rat

e p

er 1

,000

peo

ple

Year

Rate ofnatural increase

Crudebirth rate

Crudedeath rate

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

© 2004 B

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Learn

ing

Developing Countries

50

40

30

20

10

01775 1800 1850 1900 1950 2000 2050

Rat

e p

er 1

,000

peo

ple

Crudebirth rate

Rate ofnaturalincrease

Crudedeath rate

Year

© 2004 B

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Learn

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Population Age StructurePopulation Age Structure

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

3 main age categories3 main age categories Prereproductive: 0 – 14 yearsPrereproductive: 0 – 14 years Reproductive: 15 – 44 yearsReproductive: 15 – 44 years Postreproductive: 45 and upPostreproductive: 45 and up

Represent a good comparison between Represent a good comparison between countriescountries

Compare Growth Compare Growth Rapid, Slow, Zero, Rapid, Slow, Zero, NegativeNegative

Male Female

Rapid GrowthGuatemala

NigeriaSaudi Arabia

Slow GrowthUnited States

AustraliaCanada

Male Female

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

© 2004 Brooks/Cole – Thomson Learning

Zero GrowthSpainAustriaGreece

Negative GrowthGermanyBulgariaSweden

Male Female Male Female

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

© 2004 Brooks/Cole – Thomson Learning

Age Structure & Population GrowthAge Structure & Population Growth Country with many people under 15 has Country with many people under 15 has

large potential for population increaselarge potential for population increase Depends on the number of females as Depends on the number of females as

wellwell In 2002 30% of world population In 2002 30% of world population

was below 15 (33% in developing was below 15 (33% in developing countries)countries)

Population has stabilized or declining in Population has stabilized or declining in most developed countriesmost developed countries

Many developing countries expected to Many developing countries expected to double or triple before stabilizingdouble or triple before stabilizing Mexico, Ethiopia, Nigeria, Pakistan, BrazilMexico, Ethiopia, Nigeria, Pakistan, Brazil

Population Population MomentumMomentum

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

Projections of Population and Projections of Population and EconomicsEconomics

Track the baby boomers through age Track the baby boomers through age pyramidspyramids

Currently ½ of adult AmericansCurrently ½ of adult Americans Dominate demand for goods, services, Dominate demand for goods, services,

& control politics and laws& control politics and laws The social security problem – Paid for The social security problem – Paid for

by current workers, fewer than by current workers, fewer than boomersboomers

Future impact = later retirement, Future impact = later retirement, more taxes, …more taxes, …

20

Age

Females Males

1955

16128 44 8121620

Millions

Age

242016128 4 4 812162024

Females Males

1985

Millions© 2004 Brooks/Cole – Thomson Learning

Age

Females Males

2015

20161284 4812162020

Millions

Age

2420161284 4812162020

Females Males

2035

Millions

194541.9 workers

40

30

20

10

0

195016.5

20751.9

1945 2000 2050 2075

Nu

mb

er o

f w

ork

ers

sup

po

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oci

al S

ecu

rity

ben

efic

iary

Year

Problems with Population declineProblems with Population decline

If many populations stable nowIf many populations stable now At some future time they will begin to At some future time they will begin to

declinedecline By 2050 – 39 countries are expected By 2050 – 39 countries are expected

to be in declineto be in decline If rapid, can cause problems (1) If rapid, can cause problems (1)

consume public services, health care, consume public services, health care, social security; (2) labor shortage, social security; (2) labor shortage, increased reliance on immigrant laborincreased reliance on immigrant labor

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

Population decline from rising Population decline from rising death ratesdeath rates

HIV epidemic in Africa kills 6000 dailyHIV epidemic in Africa kills 6000 daily Kills mostly young adultsKills mostly young adults

Sharp decrease in average life expectancySharp decrease in average life expectancy Loss of productive workersLoss of productive workers Rise in numbers of orphansRise in numbers of orphans Drop in food production with loss of laborersDrop in food production with loss of laborers

Need new Marshall PlanNeed new Marshall Plan Reduce HIV spread: education, health servicesReduce HIV spread: education, health services Restore economic progress: aid as $ & Restore economic progress: aid as $ &

volunteersvolunteers

Is the world overpopulated?Is the world overpopulated?

Wrong question?Wrong question? What is the optimum number of people What is the optimum number of people

that can be sustainably supported by that can be sustainably supported by the earth without further the earth without further environmental degradationenvironmental degradation

Optimum would allow people to live Optimum would allow people to live comfortably without harming future comfortably without harming future generationsgenerations

SolutionsSolutions

1.1. Reducing births!Reducing births!- Violation of personal and religious Violation of personal and religious

freedomsfreedoms- Viewed as a form of genocide by some Viewed as a form of genocide by some

ethnic groupsethnic groups- BUTBUT- We currently don’t provide basic needs We currently don’t provide basic needs

for 1/6 of the world populationfor 1/6 of the world population- Increasing environmental harm & death Increasing environmental harm & death

ratesrates- Life span longer today so we have a Life span longer today so we have a

greater per person impact toogreater per person impact too

Demographic Transition HypothesisDemographic Transition Hypothesis As countries become industrialized first As countries become industrialized first

death rate then birth rate will declinedeath rate then birth rate will decline1.1. Preindustrial Stage Preindustrial Stage harsh living conditions harsh living conditions

= little population growth, high B & D= little population growth, high B & D2.2. Transitional Stage Transitional Stage industrialization starts, industrialization starts,

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

3.3. Industrial Stage Industrial Stage Industry continues = Industry continues = population grows but slowly, B > D by a littlepopulation grows but slowly, B > D by a little

4.4. Postindustrial Stage Postindustrial Stage population growth population growth stops, B = D (13% of world) then B < D an stops, B = D (13% of world) then B < D an may start to decline (this may be stage 5)may start to decline (this may be stage 5)

Low

High

Rel

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siz

e

Bir

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ate

an

d d

eath

rat

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um

ber

per

1,0

00 p

er

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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 ComparisonsDemographic Transition Comparisons

Demographic Transition HypothesisDemographic Transition Hypothesis

Most developing countries today have Most developing countries today have death rates declining more than birth death rates declining more than birth ratesrates

Still in Transitional stageStill in Transitional stage Fear that population growth in these Fear that population growth in these

areas will overcome economic growthareas will overcome economic growth Demographic TrapDemographic Trap: get stuck in a stage: get stuck in a stage Countries lack skilled workers, capital & Countries lack skilled workers, capital &

resources, drop in economic assistanceresources, drop in economic assistance

Can we reduce Birth ratesCan we reduce Birth rates

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

1.1. Family Planning – info on birth spacing, Family Planning – info on birth spacing, birth control and prenatal carebirth control and prenatal care

2.2. Empowering women – education, job Empowering women – education, job opportunities, womens rightsopportunities, womens rights

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

3.3. Economic Rewards & Penalties – Economic Rewards & Penalties – payments to individuals who use payments to individuals who use contraceptivescontraceptives

Condom5%

Female sterilization17%

IUD12%

Othermethods

10%

Pill8%

Malesterilization

5%

No method43%

Global Contraceptive Use

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

programprogram After 50 years it is still the second most After 50 years it is still the second most

populous country in world (1 billion)populous country in world (1 billion) GNIPP is $2,340 a yearGNIPP is $2,340 a year Unemployment = 50%Unemployment = 50% 40% population, 50% children suffer malnutrition40% population, 50% children suffer malnutrition 16% world population, 2% resources16% world population, 2% resources ½ cropland degraded, 70% water seriously ½ cropland degraded, 70% water seriously

pollutedpolluted Overall, program disappointing & poorly doneOverall, program disappointing & poorly done

China: A Case StudyChina: A Case Study 1972-2002 cut crude birth rate in half, TFR 1972-2002 cut crude birth rate in half, TFR

from 5.7 to 1.8 children per womanfrom 5.7 to 1.8 children per woman Encourage late marriage & 1 child per familyEncourage late marriage & 1 child per family Contraception. Sterilization, Abortion = FREEContraception. Sterilization, Abortion = FREE RewardReward Food, $$$, School tuition, Medical Food, $$$, School tuition, Medical

carecare UN projects population drop by 2042UN projects population drop by 2042 It was either population control or It was either population control or

starvationstarvation Population still growing, mass Population still growing, mass

environmental impactenvironmental impact But projected to be on the decline by 2040But projected to be on the decline by 2040

Percentageof 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 billion1.3 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)

7231

61 years

71 years

$440

$750

IndiaChina

Cutting Global Population GrowthCutting Global Population Growth

UN encouraging world population stabilityUN encouraging world population stability

Universal access to family planningUniversal access to family planning Improve health care – infants, children, Improve health care – infants, children,

womenwomen Social & Economic plans for countriesSocial & Economic plans for countries Increase access to educationIncrease access to education Eradicate povertyEradicate poverty Eliminate unsustainable patterns of Eliminate unsustainable patterns of

production and consumptionproduction and consumption

The use of ModelsThe use of Models

We can’t see the futureWe can’t see the future But we have good predictive power But we have good predictive power

based on current numbersbased on current numbers Using birth & death rates, fertility Using birth & death rates, fertility

and extrapolation we can model and extrapolation we can model populations into the futurepopulations into the future

Models based on mathematical Models based on mathematical calculations of future predictionscalculations of future predictions

Computer SimulationsComputer Simulations

View Population connection View Population connection simulationsimulation

Demographic TablesDemographic Tables http://www.wpro.who.int/information_sources/d

atabases/demographic_tables/

Projecting Future Populations: Age/Sex PyramidsProjecting Future Populations: Age/Sex Pyramids

Graphical Extrapolation: World Graphical Extrapolation: World PopulationPopulation

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

Review TopicsReview Topics

Are these characteristics of Developing Are these characteristics of Developing or Developed Nations?or Developed Nations?

High fertility ratesHigh fertility rates High consumptive lifestyles: use 80% High consumptive lifestyles: use 80%

of world’s wealthof world’s wealth Intense povertyIntense poverty Eat high on the food chainEat high on the food chain Long doubling timesLong doubling times High environmental degradationHigh environmental degradation Twenty percent of the world’s Twenty percent of the world’s

populationpopulation

Compare Projected Populations in Compare Projected Populations in Developing and Developed CountriesDeveloping and Developed Countries

Fertility Rate> 2

Fertility Rate< 2

Plumpy nutPlumpy nut Life strawLife straw

Consequences of Exploding Consequences of Exploding PopulationsPopulations

More PopulationCauses MORE

LESS

deforestationresource depletionloss of agricultural landdiseasepopulation migrationIrrigation

biodiversitypest resistancewetlands