© 2006 population reference bureau world population growth

© 2006 Population Reference Bureau

World World population population

growthgrowth


A.D.2000

A.D.1000

A.D.1

1000B.C.

2000B.C.

3000B.C.

4000B.C.

5000B.C.

6000B.C.

7000B.C.

1+ million years

8

7

6

5

2

1

4

3

OldStoneAge New Stone Age

BronzeAge

IronAge

MiddleAges

ModernAge

Black Death —The Plague

9

10

11

12

A.D.3000

A.D.4000

A.D.5000

18001900

1950

1975

2000

2100

Future

Billions

Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998).

World Population Growth Through History


Why is world population growing so fast?

• Compare life today with conditions 100 years ago:

• Agriculture• Medicine• Sanitation• Health care• Transportation

• More people reach child-bearing age and have children


Factors that limit population growth

• Famine

• Disease

• War


Trends in Population Growth Worldwide

Population Increase and Growth Rate, Five-Year Periods

80

8783

7976 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

cen

t in

crea

se p

er y

ear

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


Billions

0

1

2

3

4

5

6

7

8

9

10

1950 1970 1990 2010 2030 2050

Less Developed Regions

More Developed Regions

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

Growth in More, Less Developed Countries


Africa and Other Developing Regions Make Up an Increasing Share of World Population


Less developed countries


More developed countries


population pyramids:

• graphically display a population's age and gender composition;

• are bar graphs;

• show numbers or proportions of males and females in each age group;

• show gains of cohort members due to immigration and birth, and loss of cohort members due to emigration and death;

• and reflect population growth or decline.


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


Less developed countries have significantly younger populations.

Almost 1/3 of the population in less developed countries is under age 15.

2 billion young people under age 20 in less developed regions.

In contrast, less than 1/5 of the population in more developed countries is under age 15.

Notes on Age Distribution of the World’s Population


Population

• Demography - The study of size, birth, and death rates, and distribution of humans

• Adding to a human population:– Birth rate and immigration

• Subtracting from a human population:– Death rate and emigration

Birth rates haven't increased much in our world, but death rates have become much lower in the past century.


Lowest and Highest Infant Mortality Rates

© 2006 population reference bureau world population growth

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