Our Crowded Future

Stan Becker, ProfessorDepartment of Population, Family and

Reproductive Health

Summer 2008

Ninth

Eighth

Seventh

Sixth

Fifth

Fourth

Third

Second

First Billion All of Human History (1800)

130 (1930)

30 (1960)

15 (1975)

12 (1987)

12 (1999)

14 (2013)

14 (2027)

21 (2048)

World Population Growth, in BillionsNumber of years to add each billion (year)

Sources: First and second billion: Population Reference Bureau. Third through ninth billion: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.© Population Reference Bureau 2006.

World Population Growth

0

2,000

4,000

6,000

8,000

10,000

12,000

1750 1800 1850 1900 1950 2000 2050

More Developed Countries Less Developed Countries

2007:6.6 Billion

Population growth, 1750-2050

Sources: Before 1950: PRB estimates; 1950-2050: adapted from UN, World Population Prospects: The 1996 Revision, 1998 (medium scenario).

World Population Clock 2005

1371512154Minute197,004217,9713,383221,354Day

71,906,58779,559,3111,234,90780,794,218Year

Less Developed Countries (less China)

Less Developed Countries

More Developed CountriesWorld

Natural Increase per

Source: Population Reference Bureau, 2005 World Population Data Sheet.

Trends in Population Growth WorldwidePopulation Increase and Growth Rate, Five-Year Periods

8087

8379 76 76 75 72

0

10

20

30

40

50

60

70

80

90

1980-1985

1985-1990

1990-1995

1995-2000

2000-2005

2005-2010

2010-2015

2015-2020

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Net population added per year Annual population growth rate

Mill

ions

Per

cent

incr

ease

per

yea

r

Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

Population Trends by Region 1950-2050

0

1

2

3

4

5

6

Asia Africa LatinAmerica

Europe NorthAmerica

Bill

ions

195020002050 (projection)

Source: United Nations 2001

U.S. Population growth

• Net Immigration• At least 800,000 legal immigrants• Approximately 400-500,000 net

undocumented• Relatively small number of emigrants• Approximately 4.1 million births• Approximately 2.4 million deaths• NET GROWTH= ABOUT 3 MILLION

Source: “International Migration 2006” UN Population Division Wall Chart, 2006.

Source: “International Migration 2006” UN Population Division Wall Chart, 2006.

Some Simple Mathematics

Crude birth rate (CBR) = Births x 1000Total population

Crude death rate (CDR) = Deaths x 1000Total population

Crude rate of increase (CRI) = Births-deaths x 1000 Total population

World population increase = 78 million per yearTotal world population = 6.6 billion

So 78 million x 1000 = 11.8 CRI or 1.18% growth per year6.6 billion

Population Structures by Age and Sex, 2005 Millions

300 100 100 300300 200 100 0 100 200 300

Less Developed Regions

More Developed Regions

Male Female Male Female

80+ 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-90-4

Age

Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

Age Distribution of the World’s Population

Population by Age: Developing World

0 200 400 600 800

0-4

10-14

20-24

30-34

40-44

50-54

60-64

70-74

Age

Population (millions)Source: United Nations 2001

1950 1975 2000 2025 2050

Old Age Dependency Ratio by Region

0

0.1

0.2

0.3

0.4

0.5

1950 1975 2000 2025 2050Year

Rat

io

Source: United Nations 2001

Europe

Asia

L. America

Africa

N.America

Median age of the population for various countries

Country Median ageWorld 27.8Japan 43.5Italy 42.5Belgium 41.1USA 36.6Taiwan 35.5Sri Lanka 30.0Turkey 28.6South Africa 24.3Egypt 24.2Ethiopia 18.0Malawi 16.7Uganda 14.9

Source: World Urbanization Prospects, The 2007 Revision Executive Summary, UN Division of social and economic affairs

Urban PopulationPercent

29

15 17

5347

37 37

76

55

42

74

85

54

61

82

World Africa Asia Latin Americaand the

Caribbean

MoreDeveloped

Regions

1950 2000 2030

Source: United Nations, World Urbanization Prospects: The 2003 Revision (medium scenario), 2004.

Trends in Urbanization, by Region

Time

Stage 1 Stage 2 Stage 3 Stage 4

Naturalincrease

Birth rate

Death rate

Note: Natural increase is produced from the excess of births over deaths.Source: Population Reference Bureau, 2008

The Classic Stages of Demographic Transition

Total Fertility Rate (TFR) by RegionPast Estimates and Projections

0

1

2

3

4

5

6

7

1950 1975 2000 2025 2050

Birt

hs p

er w

oman

Source: United Nations 2001

L.America

AfricaAsia

N.America

Europe

Patterns of Fertility DeclineAverage number of children per woman

0

2

4

6

8

10

1950–1955 1960–1965 1970–1975 1980–1985 1990–1995 2000–2005

Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

Uganda

Kenya

Colombia

South Korea

Reaching Replacement FertilityAverage number of children per woman

5.6

7.0

5.4

6.4

5.7

7.3

1.9 2.0 2.1 2.0 1.9 2.0

Azerbaijan Chile Iran Mauritius Thailand Tunisia

1960-1965 2000-2005

Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

Intermediate Fertility VariablesExposure factors

1. Proportion marriedDeliberate marital fertility control factors

2. Contraception3. Induced abortion

Natural marital fertility factors4. Lactational infecundability5. Frequency of intercourse6. Sterility7. Spontaneous intrauterine mortality8. Duration of the fertile period

EASTERN EUROPESOUTHERN EUROPE

EAST ASIAWESTERN EUROPE

NORTHERN EUROPENORTHERN AMERICA

SOUTH AMERICACARIBBEAN

SOUTHEAST ASIACENTRAL

SOUTHERN AFRICASOUTH CENTRAL ASIA

NORTHERN AFRICAWESTERN AFRICA

SUB-SAHARAN AFRICAEASTERN AFRICAWESTERN AFRICA

MIDDLE AFRICA 6.3

5.55.7

1.82.0

2.4

3.4

5.5

2.8

2.52.7

2.8

3.03.1

1.6

1.31.4

1.6

59%

58%54%

50%

51%22%25%

13%25%

58%

74%82%

73%

75%55%

84%

63%

Total Fertility Rate Contraception Prevalence

66%

# of children per woman percentage

Source: PRB, 2007 World Population Data Sheet

Pill8%IUD

14%

Injectable or Implant

3%

Male Condom5%

Female Sterilization

21%

Not Using39%

Other Modern Methods

1%

Traditional Methods

7%Male Sterilization

3%

Note: Total exceeds 100 due to rounding.Source: United Nations Population Division, World Contraceptive Use 2005.

Married or In-Union Women of Reproductive Age Using Family Planning, 1999

Childbearing and Women’s EducationAverage number of children per woman, by educational level, 2000-2004

Sources: Demographic and Health Surveys: Kenya 2003, Madagascar 2003-4, Egypt 2000, Bangladesh 2004, Bolivia 2003.

6.7 6.5

4.13.6

6.8

5.54.9

3.2 3.13.8

5.7

3.42.52.5

3.3

0

12

34

56

7

Kenya Madagascar Egypt Bangladesh Bolivia

No formal education Primary completed Secondary completed

Family Planning and Women’s Education

8 5

50 49

18

29

19

5647

30

52

28

58

48 46

010203040506070

Kenya Madagascar Egypt Bangladesh Bolivia

Per

cent

No formal education Primary completed Secondary completed

Percent women ages 15-49 using family planning, by educational level, 2000-2004

Sources: Demographic and Health Surveys: Kenya 2003, Madagascar 2003-4, Egypt 2000, Bangladesh 2004, Bolivia 2003.

Life Expectancy Trends in Africa

30

40

50

60

70

80

90

1925 1950 1975 2000 2025 2050

Year

s

South Africa

Africa

Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat (2007). World Population Prospects: The 2006 Revision, Population Database. New York: United Nations.

Components of Population Growth Developing World

0

2

4

6

8

10

1950 2000 2050 2100

Popu

latio

n si

ze (b

illio

ns)

Source: Bongaarts and Bulatao 1999

Standard Projection Effect of

Fertility abovereplacementDeclining

Momentummortality

This calculation uses the global average per capita area demand (EF). For 1999 that worldwide average EF was 2.3 hectares per person. This is significantly lower than the average EF in industrialized countries such as the United States (9.7 hectares per person), the United Kingdom (5.4 hectares per person) and Germany (4.7 hectares per person) (Living Planet Report 2002). Note for our readers in the U.S. 1 hectre = 2.5 acres.

If all the world used resources at the rate that the U.S. does, we would need more than THREE earths to sustain life.

I = P*A*T formula

I = impact of humans on the environment/ecosphere

P = populationA = affluence per capitaT = impact of technology to produce that

affluence

Introductory Courses inPopulation and Health

Principles of Population Change

Demographic Methods for Public Health

Application of Population Data for Policy andPractice (New Course)

Other courses in Population and Health

Title Quarter

Social and economic aspects of humanfertility

1

Couples and reproductive health 1Biosocial population research 2Fundamentals of life tables 3Dynamics of population aging 3Migration and health (new course) 3Economics of gender and family 4Poverty, economic development and health 4Methods and measures in population studies 4

THANK YOU