Chapter 22- Population, urbanization and the environment
Demography: the study of population
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Until 250 years ago the world pop. Was around 500 mil.
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Life span was shorter than it is now
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77 million ppl added to the planet each year
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6.2 billion in 2002
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Demography- the study of human population
Fertility
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The incline of child bearing in a country’s population
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A women could possibly bear 20 children but this poses many problems
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Crude birth rate- number of live births for every thousand ppl in the population
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Calculated by diving the number of births by a population and multiplying
it by 1000
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2002, Canada- 327 882 love births with population of 30million
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Crude birth rate of 10.9
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Newfoundland- 8.8- low due to out migration
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Quebec is low because many women entered the work force
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Funafuti- 25.2
Mortality
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The incidence of death in a women population
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Crude death rate
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Same as birth rate
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Canada in 2002- 7.5
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Infant morality rate- rate of death in infants in the first year of life for each
thousand life births in a year
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Found by dividing the number of deaths of infants by live births and
x1000
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2001-5,0 per 1000
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Life expectancy- average life span of a societies population
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Canadian born males in 1997 can expect to live to 76 while women can
live to 81
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Life expectancy is in rich countries is 20 years longer than poor.
Migration
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The movement of ppl into and out of a specific territory
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Migration is sometimes involuntary
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It is also due to push-pull factors
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Dissatisfaction with life in poor countries is a push factor
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Pull factors include attractions to big city where oppurntity is greater
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Immigration
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Movement of people into a country.
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In-migration rate- The number entering per every thousand ppl
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Emigration
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The movement of people out of a country.
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Out-migration rate- ppl leaving per every thousand
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Net-migration rate is the result of both in and out migration
Population growth
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Affected by migration, morality, fertility
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Natural growth rate- subtract crude birth and death rates
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2002- Canada’s natural growth rate was 3.3.
Population composition
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One variable is
sex ratio
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Number of males to every 100 females
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In 2001 ratio was 98 men per 100 females
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Women tend to outlive men
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Ratio is 1007 in India. This could be because they value males more and
abort females at birth
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Age-sex pyramid
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Graphic representation of the age and sex in population
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The bulge in the pyramid of women when they’re 30 reps. the baby boom.
Just below that represents the baby bust
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Through age sex pyramids we can predict demographic trends
History and the theory of population growth
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Societies desired high birth rates due to high death rates
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A critical point in world population growth occur din the 1750’s as the earth
population turned upwards
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Population currently 6 billion
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1800- I billion
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1930- 2 billion
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1962-3 billion
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1974-4 billion
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1999- 6 billion
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By 2050- presumed to be 7-8 billion as it gains 77 million ppl year
Malthusian theory
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Thomas Malthus

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- Spring '05
- None
- Sociology, Demography, Life expectancy, World Population Growth
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