Title: Human Population Growth
1Human Population Growth
2Factors 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
3World 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
4World 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
5Human 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
6Human 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
7Fertility 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)
8United 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
9United States Historical Trend in Total Fertility
Rate
10Factors 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-
11Factors 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
12Factors That Decrease Death Rates
- Increased food supply and distribution
- Better nutrition
- Medical improvements
- Increased sanitation
- Better water supply
13Two 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)
14Infant Mortality Rates
15Population 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
16Population Age Structure
17Population Study-Example
18Populations Affected by Immigration
19Cultural 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
20Demographic 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
21Preindustrial Stage
- Little population growth because of harsh
conditions - High birth AND death rates
22Transitional Stage
- Population grows rapidly when industrialization
improves - High birth rates, lowering death rates
- Stage that developing nations are in currently
23Industrial Stage
- Population growth slows as birth rates drop and
eventually approach death rates
24Postindustrial Stage
- Birth ratedeath rate
- Zero population growth
- U.S., Japan, Europe (some populations are even
decreasing)
25Demographic Transition
26India
- 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?
27India
28China
- 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
29China
- 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?
30China
31Cutting 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
32Cutting 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
33World Population