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Human Population Growth

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Title: Human Population Growth


1
Human Population Growth
2
Factors Affecting Human Population Size
  • Births
  • Deaths
  • Migrations
  • Immigration individuals moving into a pop.
  • Emigration individuals moving out of a pop.
  • Population Change
  • (birthsimmigration)-(deathsemigration)
  • When births and immigration is greater than
    deaths and emigration, the population will
    increase
  • http//www.youtube.com/watch?v4BbkQiQyaYc
  • http//www.youtube.com/watch?vsc4HxPxNrZ0feature
    related

3
World Population
  • Rate of annual pop change is expressed as a
    percentage birth rate-death rate 10
  • The U.S. had a birth rate of 14.6 live births per
    1,000 population in one year, compared to Indias
    birth rate of 22.2 in that same year. The death
    rate in that year for the U.S. was 8.3 deaths per
    1,000, compared to Indias rate of 6.4.
    Calculate the population growth rates () for
    both countries.
  • U.S. 14.6-8.3 0.6 10
  • India 22.2-6.4 1.6 10


4
World Population
  • Exponential growth has not disappeared, but its
    occurring at a slower rate
  • Between 1963 and 2002, the population rose from
    3.2 to 6.2 billion
  • 79 million people were added in 2002, compared to
    69 million in 1963 when the worlds pop growth
    rate was at its highest

5
Human Population Growth over Time
  • Before agricultural revolution 1-3 million
    humans, hunter/gatherers, Earth Wisdom-natural
    cycles serve as models for human behavior
  • 8000 BCE-5000BCE 50 million humans, increases
    due to agricultural revolution
  • 5000 BCE-1 BCE 200 million humans, Frontier
    Worldview-undeveloped land as a hostile
    wilderness to be conquered, exploited resources
  • 0 BCE-1300 CE 500 million humans
  • 1300-1650 CE 600 million humans, plagues
    reduced population growth rate

6
Human Population Growth over Time
  • 1650-present 7 billion humans, reductions in
    death rates, increase medical technology,
    Planetary Management-as we are the planets most
    important species, we are in charge of earth, we
    will develop new resources so should not worry
    about using them sustainably
  • Present-2050 9 billion (?), Earth
    Wisdom-resources are limited so should be
    conserved, we should encourage sustainable use of
    resources because the earth exists for all nature

7
Fertility Rates
  • Replacement Level Fertility- of children that a
    couple needs to have in order to replace
    themselves (2.1 in developed countries/2.5 in
    developing countries)
  • Total Fertility Rate (TFR)-an estimate of the
    of children a woman will have during childbearing
    years (based on the previous year)

8
United States Historical Trend in Total Fertility
Rate
  • 1910-1930 birth rates dropped due to
    urbanization
  • 1930s stayed low because of the Great
    Depression
  • 1940s rising again
  • 1957 TFR3.7 children/woman, highest
  • 1946-1964 Baby Boom
  • 1965-1977 Baby Bust
  • 1977-2000 Echo Boom

9
United States Historical Trend in Total Fertility
Rate
10
Factors that Affect Average Birth Rate and TFR
  • Children are part of the labor force-
  • Urbanization-
  • High cost of raising and education children-
  • High infant mortality rate-
  • Older average age of marriage-

11
Factors that Affect Average Birth Rate and TFR
  • High availability of pension systems-
  • Availability of legal abortions-
  • Availability of birth control-
  • Men included in child-rearing responsibilites-
  • Religious beliefs, traditions, cultural norms

12
Factors That Decrease Death Rates
  • Increased food supply and distribution
  • Better nutrition
  • Medical improvements
  • Increased sanitation
  • Better water supply

13
Two Indicators of Overall Health
  • Life expectancy average of years people live
  • Global life expectancy 76 in developed
    nations/65 in developing nations
  • US 77 yrs.
  • Africa 55 Yrs.
  • Infant Mortality Rate of babies out of 1000
    that die before their first birthday
  • High infant mortality rate indicates insufficient
    food, poor nutrition, high incidence of
    infectious disease (water supply)

14
Infant Mortality Rates
15
Population Age Structure
  • The proportion of the pop of each sex at each age
    level used to make pop and economic projections
  • Age levels
  • Prereproductive (0-14)
  • Reproductive (15-44)
  • Post reproductive (45 and up)
  • Age structure affects population growth
  • Countries with a wide base (lots of people below
    15) will increase in size if death rate stays the
    same

16
Population Age Structure
17
Population Study-Example
  • Social security crisis

18
Populations Affected by Immigration
  • U.S.
  • Canada
  • Australia

19
Cultural Carrying Capacity
  • Different from actual of individuals an area
    can support b/c of culture when land is used to
    grow feed for cattle it expends more energy thus
    reducing carrying capacity
  • Eating high on the food chain uses up to 50x more
    land than eating a vegetarian diet
  • 43 of U.S. is used for grazing or feed for
    livestock meats impact on the environment is
    second only to automobiles

20
Demographic Transition
  • Demography study of human population
  • As countries become industrialized first death
    rates, but then birth rates decline
  • Four Stages
  • Preindustrial Stage
  • Tansitional Stage
  • Industrial Stage
  • Postindustrial Stage

21
Preindustrial Stage
  • Little population growth because of harsh
    conditions
  • High birth AND death rates

22
Transitional Stage
  • Population grows rapidly when industrialization
    improves
  • High birth rates, lowering death rates
  • Stage that developing nations are in currently

23
Industrial Stage
  • Population growth slows as birth rates drop and
    eventually approach death rates

24
Postindustrial Stage
  • Birth ratedeath rate
  • Zero population growth
  • U.S., Japan, Europe (some populations are even
    decreasing)

25
Demographic Transition
26
India
  • 1.1 billion people
  • 16 of worlds people, but only 2.3 of worlds
    land resources and 2 of worlds forests
  • 70 of water seriously polluted
  • Tried family planning, but not very successful
  • Why?

27
India
28
China
  • 1.3 billion people
  • Since 1970, cut its crude birth rate in half and
    decreased TFR from 5.7 to 1.8 children/woman
  • How?
  • Free sterilizations/contraception/abortions
  • Couples who have only one child receive extra
    food, larger pensions, better housing, free
    medical care, salary bonuses, free school tuition
    for their child, and preferential treatment in
    employment when their child enters the work force

29
China
  • Projected that Chinas pop will begin to decline
    in 2042, but what about their aging
    population/social security?
  • Should other countries impose such severe
    restrictions/limitations on human freedoms to
    achieve pop control?

30
China
31
Cutting Global Population Growth
  • Provide access to family planning services and
    reproductive health care
  • Improve health care of infants, children,
    pregnant women
  • Implement population policies
  • Improve job opportunities for women
  • Increase access to education, especially to women
  • Increase involvement of men in child-rearing
  • Eradicate poverty
  • Reduce/eliminate unsustainable patterns of
    production and consumption

32
Cutting Global Population Growth
  • Goal of Cairo Commitment stabilize pop growth
    at 7.8 billion by 2050 instead of projected 9-11
    billion
  • BTW we are already at 6.7 billion..
  • World Clock

33
World Population
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