Global Population Trends

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Chapter 2

• Global Population Trends

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Chapter Outline

• World Population Growth
• Geographic Distribution Of The Worlds Population
• Global Variation In Population Size And Growth
• Global Demographic Contrasts

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Cartogram of Countries of the World by Population
Size
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Cartogram of Countries of the World by Population
Size
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A Brief History

• Human beings have been around for at least
  200,000 years.
• For almost all of that time, humans were
  hunter-gatherers living a primitive existence
  marked by high fertility and high mortality, and
  very slow population growth.
• The population of the world on the eve of the
  Agricultural Revolution 10,000 years ago is
  estimated at about four million.

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A Brief History

• Many argue that the Agricultural Revolution
  occurred because the growth of hunting-gathering
  populations pushed the limit of their carrying
  capacity.
• Over tens of thousands of years humans moved to
  remote corners of the earth in search of
  sustenance.
• They began to use the environment intensively,
  leading to the agricultural way of life that has
  characterized society for the past 10,000 years.

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A Brief History

• Between 8000 B.C., and 5000 B.C., about 372
  people were added to the worlds population each
  year.
• By 500 B.C., as major civilizations were
  established in China and Greece, the world was
  adding about 139,000 people each year.
• By 1 A.D., there may have been more than 200
  million people on the planet, increasing by over
  300,000 a year.

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A Brief History

• In the 3rd through 5th centuries A.D., increases
  in mortality led to declining population in the
  Mediterranean area as the Roman Empire collapsed,
  and in China as the Han empire collapsed.
• Population growth recovered until the plague
  arrived in Europe in the middle of the 14th
  century.

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A Brief History

• In the middle of the 18th century, on the eve of
  the Industrial Revolution, the population of the
  world was approaching one billion and was
  increasing by 2.6 million every year.
• Since the beginning of the Industrial Revolution
  approximately 250 years ago, the size of the
  worlds population has increased dramatically.

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Population Growth
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Population Growth
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Population Growth
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Population Growth
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Doubling Time

• The time required for a population to double if
  the current rate of growth continues.
• The doubling time is approximately equal to 69
  divided by the growth rate.
• Estimate the worlds rate of growth in the year
  2003 to be 1.2 per year, the doubling time is 58
  years.

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The Worlds Population Has Exploded in Size
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75 Million People Are Added to the Worlds
Population Each Year
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In One Day the Worlds Population Increases by
More than 200,000
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Why Was Early Growth Slow?

• During the hunting-gathering phase, life
  expectancy averaged 20 years.
• More than half of children born died before 5.
• The average woman who survived the reproductive
  years would have to bear nearly 7 children to
  assure 2 survived to adulthood.

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Why Are More Recent Increases More Rapid?

• Acceleration in population after 1750 was due to
  declines in the death rate during the Industrial
  Revolution.
• People were eating better, bathing more often and
  drinking cleaner water.
• Continuing population increases are due to
  dramatic declines in mortality without a
  commensurate decline in fertility.

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Redistribution of the Worlds Population through
Migration

• Migration flows from rapidly growing areas into
  less rapidly growing ones
• Latin America and Asia to the United States
• Asia to Canada
• Africa and Asia to Europe
• In earlier decades, as population grew dense in a
  region, people moved to a less populated area

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Less Developed Regions and Future Population
Growth (to the Year 2050)
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Less Developed Regions and Future Population
Growth (to the Year 2050)
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Less Developed Regions and Future Population
Growth (to the Year 2050)
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How Many People Ever Lived?

• Our current contribution to historys total
  population represents a relatively small fraction
  of all people who have ever lived.
• The formulas of Nathan Keyfitz suggest that a
  total of 61.3 billion people have been born over
  the past 200,000 years, of whom the 6.6 billion
  alive in 2008 constitute 10.6.

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The Urban Revolution

• As recently as 1800, less than 1 of the worlds
  population lived in cities of 100,000 or more.
• More than 1/3 of all humans now live in cities of
  that size.
• Urban populations grew in some countries even
  without industrialization, as places sprang up
  where goods and services were exchanged.

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Worlds 10 Most Populous Countries

• Peoples Republic of China
• India
• United States
• Indonesia
• Brazil

• Russia
• Bangladesh
• Russia
• Japan
• Nigeria

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Rates of Population Growth are Highest in the
Middle Latitudes