2. World Population Growth
• In 6000 BCE the world’s population was 5
• By 1 CE, the world’s pop was over 250 million.
• 200 years ago, the world’s pop reached 1
• In 1960, the world’s pop was 3 billion.
• Today – over 7.2 billion, we reached 7 billion on
Oct 31, 2011.
• The UN estimates that the world’s pop will
increase to 10 billion by 2010.
5. Why is this important?
• One of the greatest single factors affecting
quality of life around the world is population.
• As the populations of individual countries
fluctuate, so must the social, economic, and
political policies that are in place.
• With an increase in population, there is a
greater demand for resources, which can often
lead to environmental damage such as ozone
depletion, deforestation, and soil erosion.
• The study and analysis of trends relating to
• This type of study dates all the way back to
ancient times, but has changed considerably
over the years.
• For example, most demographers today agree
that the world’s rate of pop growth needs to
slow down. But in ancient times, pop growth
• The most complete way to gather info about
pop is to conduct a pop census.
7. Population Rates
Components of population change are:
· How many people are born
· How many people die, and
· How many move in or out of an area
Population Change Equation:
Births – deaths
+ immigrants (people moving INTO country)
– emigrants (people moving OUT OF
8. Rule of Seventy
• a convenient way to express exponential population
growth – is to use the length of time it would take for a
population to double in size – can apply the “rule of
• It states that doubling time (the period of years it
takes a country to double its population at its current
birth rate) is approximately equal to 70 divided by the
growth rate (in percent).
• Example: Gabon’s present rate of natural increase
has a doubling time of approximately 47 years:
• 70 divided by 1.5 (per cent growth per year) = 46.7
9. Life Expectancy
• life expectancy – the average number of years that
an adult is expected to live
• in 1700’s – people had a life expectancy of about 30
• today in Canada (2012) – over 82 years
• Factors contributing to death rate, thus shorter life
disease, poor nutrition, poor medical care, unsanitary
• before 1700’s - birth rates were high, but so were
death rates – so had several children to ensure that a
• also needed more children to help farm the land and
provide security to parents in their old age – this
situation still common today in developing countries
10. Pop Growth after 1750
• Rapid changes in population growth after 1750
– mainly due to falling death rates because:
agricultural revolution – increased food
production, so people had better diets
• -hygiene and medical knowledge improved
• -clean drinking water, a more varied, nutritious
diet, and vaccination against infectious
diseases meant far more children survived to
become parents themselves
• -birth rates remained high for a number of
years, producing a wide gap between birth and
death rates and a rapid growth in population
11. • Shift in Population growth again when falling death
rate was matched by decline in birth rate – reasons
1. - economic development
2. - move to cities
3. - rising standards of living
• After WWII – World Heath Organization (WHO) and
aid programs made improved health measures
available to all countries
• Result: death rates fell, but birth rates are still high in
many developing countries – this explains the rapid
growth in areas of the world, such as Africa, that do
not have significant economic development
13. Canada’s Population
• Canada’s birth and death rates have been
dropping in the past 30 years.
• This means the pop is getting older.
• 1951 – 1 in 10 cdns was over 65.
• 2020 – 1 in 5 will be over 65.
• Life expectancy in Cdn ↑ from an average of 45
years in 1900 to 65 by 1950 and to 79 in 2000.
• The increasing numbers of elderly people put
immense strains on social and medical
14. Canada’s Immigration
• The age structure of Cdn’s pop is one of the
main factors the federal govt considers when
deciding on the number of immigrants Cdn
should accept each year.
• Without immigration between 1991 and 1996,
our pop would have shrunk by 750,000 instead
of increasing by more than 1.6 million.
• The average age of the Cdn pop would have
• The # of immigrants entering Cdn is around
200,000 per year.
• Govt’s goal of immigration is 1% of pop.
• Largest group of refugees
comes from China.
• More money spent on
refugee claims than on
• The growing gap between
rich and poor, unrest in the
-- all threaten to derail the