POPULATION

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POPULATION
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Population Estimates

• World 7.1 Billion
• US 320 Million
• PA 12 Million

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5 most populous states in the US

• California 37 Million
• Texas 25 Million
• New York 19 Million
• Florida 18. 8 Million
• Illinois 12.8 Million
• PA 12.7 Million

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5 most populous countries in the world

• China 1.3 Billion
• India 1.2 Billion
• US 320 Million
• Indonesia 250 Million
• Brazil 200 Million

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1-population

• Total number of people in an area

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1-population distribution

• The worlds population lives in uneven clusters
  on the Earth.
• Some places have many people, while other places
  are empty.
• Way the population is spread out over an area

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1-demography

• Science that explains
• how populations change and
• why population distribution is uneven.

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2- What do demographers study?

• Rates of birth, marriage, and death.

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3-What question do demographers ask?

• Why people move from one place to another.

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4- What are some of the reasons people
tend to move?

• They can live better in a new place.
• They are forced to move.
• They cannot feed their families.

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5- What did certain regions of the world have
that caused them to have larger populations than
others?

• Regions with a long history of farming, good
  soil, and plenty of water became crowded. These
  regions still have large populations.
• Most places that are too cold or too dry for
  farming still have small populations.

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6-What were some of the causes for new population
clusters around 1800?

1. Railroads and steamships made it easier for
   people to move long distances, even across
   oceans.
2. New jobs in factories and offices meant that more
   people were living in cities, where they could
   make a living without farming the land.

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7-Population Density

• The average number of people per square mile

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8-Which has a higher population density, a city
or an area in the countryside? Why?

• The city
• There are more people per square mile than in the
  countryside.

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9-Birthrate

• The number of live births each year per 1,000
  people

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9-Deathrate

• The number of deaths each year per 1,000 people

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10-What does population growth depend on?

• Abundant food supply
• Good soil
• Clean water
• Waste removal
• Health Care

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11-Look at the graph on page 64
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12-Look at the graph on page 64

• A. How do you calculate a country's rate of
  natural growth?
• You subtract a country's deaths from its births
• B. Which of the countries has the highest
  birthrate?
• Yemen
• C. Where is the population growing faster, The US
  of Zimbabwe?
• The United States

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12-List and explain 2 reasons for rapid
population growth after the 1700s?

• New farming methods have increased the worlds
  food supply.
• Scientists have improved important food crops and
  found new ways to protect crops against insects.
• Scientists have also found ways to raise crops
  with less water.
• Scientists have convinced local governments to
  provide clean drinking water and sanitary waste
  removal. These measures sharply reduce disease.
• Researchers have also developed vaccines to
  prevent disease and antibiotics to fight
  infections.

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13-Give and explain 3 examples of how rapid
population growth puts pressure on all aspects of
life.

1. The populations of many countries are increasing
   so fast that not everyone can find jobs.
2. There are not enough schools to educate the
   growing number of children.
3. Decent housing is scarce.
4. Public services such as transportation and
   sanitation are inadequate.

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14-Give and explain 3 examples of how rapid
population growth affects the environment

1. Forests in many countries are disappearing.
   People in poorer countries cut down the trees for
   wood and fuel.
2. Clearing forests causes other problems. In a
   forest, tree roots hold soil in place, and forest
   soils soak up rain.
3. With the forest gone, heavy rainfall may wash
   away the soil and cause dangerous floods.
4. Demand for wood and fuel in wealthier countries
   also uses up the worlds scarce resources.