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IB syllabus: 3.1.1-3.1.4
Ch 12
Video: The Population Paradox – World in the Balance
Topic 3
Human Population
Human Populations:
Population Dynamics
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• 3.1.1: Describe the nature and explain the
implications of exponential growth in human
populations
• 3.1.2: Calculate and explain, from given data,
the values of crude birth rate, crude death rate,
fertility , doubling time and natural increase rate
• 3.1.3: Analyze age/sex pyramids and diagrams
showing demographic transition models
• 3.1.4: Discuss the use of models in predicting the
growth of human populations
Topic 3
Human Population
Syllabus Statements
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3. Crude birth rate
Crude death rate
Demographic transition
Doubling time
Fertility
Rate of natural increase
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1.
2.
3.
4.
5.
6.
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Human Population
vocabulary
3
4. Factors Effecting Population Size
• 3 factors effecting population birth, death, & migration.
• Crude Death rate = # deaths / 1000 people in year population
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• Crude Birth rate = # live births / 1000 people in year population.
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Human Population
• Population change = (Birth + Immigration) – (Deaths + Emigration)
• Rates more often used.
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• Worldwide birth and death rates dropping
• Death rate dropping faster than birth rate
• 216,000 people added to world population daily
• Exponential population growth still occurring but slower
• http://www.census.gov/main/www/popclock.html Population counter
• But base number still increasing
• 79 x 106 people added per year
Topic 3
Human Population
World Population Change
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8. World Population over the Centuries
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Topic 3
Human Population
9,000 human beings added to the
planet every hour
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10. Reasons for the Human Population Explosion
• Death rates dropping faster
because of
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Human Population
B
Birth
Age
Death
Survival changed from B to A
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• Causes of disease
recognized
• Improvements in nutrition
• Discovery of antibiotics
• Improvements in medicine
• Increase in number of
women who actually reach
child-bearing age
A
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11. Implications of Exponential Growth
• Increase strain on the environment – pollution,
sanitation needs, biodiversity loss
• Increase food production & land under production
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• Outstrip our resource base – nonrenewable gone,
renewable maybe used faster than replaced
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Human Population
• Biotic potential exceeds environmental resistance: birth
rates exceed death rates
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13. • 14
• 5
• 258
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• America
• West Germany
• Africa
Topic 3
Human Population
Average Number of Children,
Grandchildren, and Great
Grandchildren
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14. • Total fertility rate (TFR)= # of children a woman
will have in her childbearing years (15-49)
• TFR = 1.6 in developed countries, 3.1 in
developing countries
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• Replacement fertility – number of children a
couple must bear to replace themselves – roughly
2.1
• Reaching replacement fertility now would still
cause population growth for another 50 years
Topic 3
Human Population
Fertility
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15. Calculating Fertility Rates and
Doubling Times
70/Rate of Increase = Doubling Time
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Topic 3
Human Population
(CBR – CDR)/10 = Rate of increase or decrease
in population per 1,000 per year
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17. Calculating Fertility Rates and
Doubling Times: Answers
CDR
Kenya
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13
Mexico
27
5
2.2
32
USA
15
9
0.6
116
11
0.2
350
431
Denmark 13
Rate of
Increase
2.0
Doubling
Time
35
Topic 3
Human Population
CBR
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Country
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19. Population projections based on TFR (H = 2.6, M = 2.1, L = 1.7)
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9
8
High
10.9
Medium
Low
Medium
9.3
7
6
Low
7.3
5
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Population (billions)
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High
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Human Population
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4
3
2
1950 1960 1970 1980 1990 2000 2010 2020 2030 2040
Year
19
2050
20. 4.0
3.5
3.0
2.5
2.1
2.0
1.5
Topic 3
Human Population
Baby boom
(1946-64)
1.0
0.5
0
1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Year
32
30
28
26
24
22
20
18
16
Demographic
14
transition
0
1910
1920
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Births per thousand population
Births per woman
US fertility and the “baby boom”
End of World War II
Depression
Baby boom
1930
1940
1950
1960
Year
Baby bust
1970
20
Echo baby boom
1980
1990
2000
2010
21. 2.
3.
4.
Importance of children for
labor higher in
developing countries &
rural areas
Urbanization more
family planning resources,
less need for children in
cities
Cost of raising or educating
children more expensive
to raise in developed areas
Education & Employment
for women less
opportunity outside of
house higher TFR
5. Infant mortality rate When
infant mortality lower fewer
children needed
6. Average age at marriage
Fewer children when 25 or
older for marriage
7. Availability of pension
Eliminate need for kids to take
care of you
8. Availability of Legal abortion
9. Availability of & Reliability of
birth Control
10.Religious beliefs, traditions,
cultural norms
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Human Population
Factors effecting Birth & TFR
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• Infant mortality and Life Expectancy are good
indicators of health in a country
• Global life expectancy is increasing
• Poorest countries it may still be low or even falling
(AIDS in Africa)
• Infant mortality encompasses nutrition & health care
so it’s a good measure
• Still 8 million infants worldwide dieing of
preventable causes in first year of life
• US – teen pregnancy rate highest of all industrialized
countries
Topic 3
Human Population
Life & Death
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25. Different Worlds
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Topic 3
Human Population
• Rich nations, poor nations
• Population growth in rich and poor nations
• Different populations, different problems
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27. Economic Categories Based on Per
Capita Gross National Income
• Middle-income, moderately developed countries
• Latin America, South Africa, China
• Average GNI per capita = $1,850
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• United States, Japan, Canada
• Average GNI per capita = $26,710
Topic 3
Human Population
• High-income, highly developed, industrialized
countries
• Low-income, developing countries
• Western and central Africa, India, central Asia
• Average GNI per capita = $430
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28. Disparities
• Developed countries
• 16% of the world’s population
• Control 81% of the world’s wealth
• Difference in per capita income: 62 to 1!
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• 41% of the world’s population
• Control 3.4% of the world’s gross national income
Topic 3
Human Population
• Low-income developing countries
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32. Population Age Structure
• Represent a good comparison between countries
• Compare Growth Rapid, Slow, Zero, Negative
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• Prereproductive: 0 – 14 years
• Reproductive: 15 – 44 years
• Postreproductive: 45 and up
Topic 3
Human Population
• Analysis by sex, of the proportion of population at each age level
• 3 main age categories
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35. Age Structure & Population Growth
• Population has stabilized or declining in most developed
countries
• Many developing countries expected to double or triple before
stabilizing
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• Depends on the number of females as well
• In 2002 30% of world population was below 15 (33% in
developing countries)
Topic 3
Human Population
• Country with many people under 15 has large potential for
population increase.
• Mexico, Ethiopia, Nigeria, Pakistan, Brazil
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• Countries like Iraq will
continue to grow for
50–60 years even after
the total fertility rate is
reduced to replacement
level.
Topic 3
Human Population
Population
Momentum
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37. Track the baby boomers through age pyramids
Currently ½ of adult Americans
Dominate demand for goods, services, & control politics and laws
The social security problem – Paid for by current workers, fewer
than boomers
• Future impact = later retirement, more taxes, …
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•
•
•
Topic 3
Human Population
Projections of Population and
Economics
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Number of workers supporting
each Social Security beneficiary
20
1950
16.5
10
1945
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Human Population
40
1945
41.9 workers
30
0
2075
1.9
2000
Year
2050 2075
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40. If many populations stable now
At some future time they will begin to decline
By 2050 – 39 countries are expected to be in decline
If rapid, can cause problems (1) consume public services,
health care, social security; (2) labor shortage, increased
reliance on immigrant labor
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•
•
•
Topic 3
Human Population
Problems with Population decline
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41. 40
30
Global
Aging
20
15
10
5
0
1950 1970 1990 2010 2030 2050 2070 2090 2110 2130 2150
Year
Under age 15
Topic 3
Human Population
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Age Distribution (%)
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Age 60 or over
Age 80 or over
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42. Population decline from rising
death rates
Sharp decrease in average life expectancy
Loss of productive workers
Rise in numbers of orphans
Drop in food production with loss of laborers
• Need new Marshall Plan
• Reduce HIV spread: education, health services
• Restore economic progress: aid as $ & volunteers
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•
•
•
Topic 3
Human Population
• HIV epidemic in Africa kills 6000 daily
• Kills mostly young adults
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• Wrong question?
• What is the optimum number of people that can be
sustainably supported by the earth without further
environmental degradation
• Optimum would allow people to live comfortably without
harming future generations
Topic 3
Human Population
Is the world overpopulated?
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44. Reducing births!
- Violation of personal and religious freedoms
- Viewed as a form of genocide by some ethnic groups
- BUT
- We currently don’t provide basic needs for 1/6 of the
world population
- Increasing environmental harm & death rates
- Life span longer today so we have a greater per person
impact too
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Topic 3
Human Population
Solutions
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45. Demographic Transition Hypothesis
As countries become industrialized first death rate then birth rate
will decline
1.
Preindustrial Stage harsh living conditions = little population
growth, high B & D
Industrial Stage Industry continues = population grows but
Topic 3
Human Population
Transitional Stage industrialization starts, better healthcare &
slowly, B > D by a little
2.
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food = population growth is rapid, high B & lower D
3.
4.
Postindustrial Stage population growth stops, B = D (13% of
world) then B < D an may start to decline (this may be stage 5)
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46. Stage 1
Preindustrial
Stage 2
Transitional
Stage 3
Industrial
Stage 4
Postindustrial
60
50
Birth rate
40
30
Death rate
20
10
Total population
0
Low
growth rate
Increasing
growth rate
Very high
growth rate
Decreasing
growth rate
Low
Low
growth rate
Zero
growth rate
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Relative population size
Birth rate and death rate
(number per 1,000 per year)
70
Topic 3
Human Population
High
80
Negative
growth rate
Time
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48. Demographic Transition Hypothesis
• Most developing countries today have death rates declining
• Fear that population growth in these areas will overcome
economic growth
• Demographic Trap: get stuck in a stage
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• Still in Transitional stage
Topic 3
Human Population
more than birth rates
• Countries lack skilled workers, capital & resources, drop in
economic assistance
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49. Doing so will reduce abortion rates & save lives as well
Family Planning – info on birth spacing, birth control and
prenatal care
Empowering women – education, job opportunities, womens
rights
2.
•
3.
Women work 2/3 all hours worked, 10% income
Economic Rewards & Penalties – payments to individuals who
use contraceptives
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1.
Topic 3
Human Population
Can we reduce Birth rates
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51. India: A Case Study
GNIPP is $2,340 a year
Unemployment = 50%
40% population, 50% children suffer malnutrition
16% world population, 2% resources
½ cropland degraded, 70% water seriously polluted
• Overall, program disappointing & poorly done
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•
•
•
•
Topic 3
Human Population
• World’s first national family planning program
• After 50 years it is still the second most populous country in world
(1 billion)
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52. China: A Case Study
• 1972-2002 cut crude birth rate in half, TFR from 5.7 to 1.8 children per
woman
UN projects population drop by 2042
It was either population control or starvation
Population still growing, mass environmental impact
But projected to be on the decline by 2040
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•
•
•
Topic 3
Human Population
• Encourage late marriage & 1 child per family
• Contraception. Sterilization, Abortion = FREE
• Reward Food, $$$, School tuition, Medical care
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53. India
China
Percentage
of world
population
16%
21%
Population (2000)
1 billion
1.3 billion
Population (2025)
(estimated)
1.4 billion
1.4 billion
Illiteracy (%of adults)
47%
36%
25%
Population growth rate (%)
Total fertility rate
1.8%
0.9%
3.3 children per woman (down from 5.3 in 1970)
1.8 children per woman (down from 5.7 in 1972)
Infant mortality rate
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Population under age 15(%)
Topic 3
Human Population
17%
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Life expectancy
GNP per capita
(1998)
61 years
71 years
$440
$750
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54. Cutting Global Population Growth
Universal access to family planning
Improve health care – infants, children, women
Social & Economic plans for countries
Increase access to education
Eradicate poverty
Eliminate unsustainable patterns of production and consumption
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•
•
•
•
•
Topic 3
Human Population
• UN encouraging world population stability
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• We can’t see the future
• But we have good predictive power based on current numbers
• Using birth & death rates, fertility and extrapolation we can
model populations into the future
• Models based on mathematical calculations of future
predictions
Topic 3
Human Population
The use of Models
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62. High fertility rates
High consumptive lifestyles: use 80% of world’s wealth
Intense poverty
Eat high on the food chain
Long doubling times
High environmental degradation
Twenty percent of the world’s population
Rule of 70 – yrs it takes for pop to double
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•
•
•
•
•
•
•
Topic 3
Human Population
Are these characteristics of Developing
or Developed Nations?
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63. Compare Projected Populations in
Developing and Developed Countries
Fertility Rate
<2
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Topic 3
Human Population
Fertility Rate
>2
63
