1. Imagine that the number of students in our AP HG Class has doubled
Imagine that the number of students in our AP HG Class has doubled. list the effects of this, both positive and negative. Would you like to have more, fewer or the same number of students in the class as now?

2. Questions:
1. What services are easier to provide for an area of high population density?
2. What qualities are desirable about areas of lower population density?
3. If population continues to grow locally, what is the impact on population density?

3. Human Geography
Unit II. Population

4. Population Geography Distribution of World Population
Population Statistics
Population Pyramids
Demographic Transition Theory
Population Control
Overpopulation (Malthus and Neo-Malthusians)

5. Population
Demography: The study of the Characteristics of human population
Demographers look statistically at how people are distributed spatially by age, gender, occupation, fertility, health, etc.
The distribution of the worlds population is in one word “uneven”

8. A little information about world Population
80% of pop. Lives within 500 Mi. of an ocean
World inhabitants live on only 10% of the land
90% of pop. Lives North of the Equator
65% lives between 20°N and 60 ° N latitude

11. Population Concentrations
23 countries = 75% of world population (172)
10 Countries have pops. Greater than 100M
China, India, United States, Indonesia, Brazil

12. World and Country Population Totals
Distribution and Structure: 3/4 of people live on 5% of earth's surface!
Total: 6.6 billion on planet as of 2007
World Clock!
Five most populous regions and countries
REGION POPULATION COUNTRY POPULATION
East Asia billion China billion
South Asia billion India million
Europe million U.S million
SE Asia million Indonesia million
East N. Am million Brazil million

13. Factors that Shape Distribution
Accessibility
Topography
Soil Fertility
Climate
Weather
Water
Political History
Economic History

14. Ecumene
Ecumene, or portion of the earth’s surface that has permanent human settlement has expanded to cover most of the earth’s land area.
Expansion of the Ecumene BC - AD 1900

15. Population Density
Density: numerical measure of the relationship between the number of people and some other unit of interest (typically space)

16. Population Density
2 Main Types of Densities
Crude/Arithmetic
Physiological

17. Arithmetic Density – the total number of people per a unit of land area. U.S. = 76/mi2; NYC=1,000,000/mi2; Australia = 7/mi2
Physiological Density – the total number of people per a unit of arable (farmable) land.

18. Crude/Arithmetic Density
Total number of people divided by the total land are (also called Population Density)
Limitations
Assumes Uniformity
One dimensional
Tells little about opportunities or obstacles contained in the relationship of people to land

19. Assumes Uniformity Example: New York State
People Per Sq. Mile (6th)
Remove NY City Population of 8 Million
And area of NYC 368 sq mi.
Density = People Per Sq. Mile

20. Population Density of Georgia

21. Physiological Density
Ratio of population to a given unit of cultivated land
Number of people dependant on each unit of cultivated land
Excludes agriculturally non-productive land
Reflects the “burden of dependency” or “carrying capacity”

22. Physiological Density
United States = 404 people are supported by 1 sq mile of arable land
Egypt = 9,073 people per sq. Mile
Why is Physiological Density More meaningful than Crude/Arithmetic Density?

23. Answer
Physiological gives us a better picture of the populations strain on the country’s resources
EXAMPLE
United States
Crude Density = 78 per sq. mi.
Physiological = 404 per sq. mi.
Egypt
Crude Density = 185 per sq. mi.
Physiological = 9,073 per sq. mi.

24. Population Density – Egypt
All but 5% of Egyptian people live in the Nile river valley
It is the only area in the country that receives enough moisture to allow intensive cultivation of crops

25. Growth

26. - Fertility and Mortality
Growth
In order to understand population growth and change we must first create an understanding of 2 significant factors:
- Fertility and Mortality

27. Measuring Population
Geographers/Demographers most frequently measure population change in a country through 3 measures

28. Measuring Population Crude Birth Rate (CBR) Crude Death Rate (CDR)
Natural Increase Rate (NIR)
Natural means excluding migration
Crude means looking at society as a whole

30. Crude Birth Rate
Total number of live births in a year for every 1,000 people alive
CBR of 20 means that for every 1,000 people in a country 20 babies are born over a one-year period
CBR for United States 2005 = 14.1
CBR = number of live births ÷ population x 1000

32. Crude Death Rate
Total number of deaths in a year for every 1,000 people
CDR for United States 2005 = 8.2
CDR = number of deaths ÷ population x 1000

34. Natural Increase Rate (NIR)
Percentage by which a population grows in a year

35. Natural Increase Rate (NIR)
Computed CBR – CDR after first converting the two measures from numbers per 1,000 to % (# per 100)
CBR = 20 , CDR = 5
20 – 5 = 15 per 1,000 or 1.5% (15÷1000 x100)

36. Natural Increase World NIR for the 1st Half of the 20th Century = 1.3
Peaked at 2.2 in 1963
Declined sharply during the past decade

37. Natural Increase 80 Million people are added to the pop. annually
High of 87 in 1989
Small % change in the NIR are very dramatic because the % affects such a large base (7 Billion)

38. Rates of Natural Increase

39. Natural Increase = CBR - CDR

40. Effects of Natural Rate on a Large Base Population

41. Demographic Equations
Growth Rate (%) = (Birth Rate – Death Rate) +/– Migration
(Rate of Natural Increase)
Population Doubling Time (yrs.) = 72  Rate of Natural Increase

43. Fertility
Total fertility rate (TFR) average number of children a woman will have throughout her childbearing years (15-49)
TFR attempts to predict the future (assumptions of future fertility on current)
World TFR is around 3.
Sub Saharan Africa >6
Europe <2

44. Total Fertility Rate (TFR)
Amount of children a women will have on average during her child bearing years.
High infant mortality tends to result in higher fertility rates as families seek “insurance” for the loss of children.
Fertility Rate = __number of live births during time period__ X 1,000
total population of females age at
mid-point of time period

45. Total Fertility Rate - the average number of children a women will have in her childbearing years. This rate varies from just over 1 (Japan, Italy) to around 7 (Niger, Mali). The U.S. rate is 2.
2.1 is generally regarded as the replacement rate (the rate at which a population neither grows nor shrinks) in the developed world. In less developed countries this rate should be higher to account for so many children not reaching childbearing age.
England & Wales

46. Total Fertility Rate

47. Influences on Birth Rates
Family planning programs
Contraceptive technology
Role of mass media
Education/opportunities for women
Child mortality rates
Affluence/wealth

48. Mortality
Infant mortality rate (IMR) annual # of deaths of infants under one year of age, compared with total live births (usually deaths per 1,000)
Infant Mortality Rate (IMR) = __number of infant deaths during time period__ X 1,000
number of live births during time period

49. Infant Mortality Rate – the number of deaths of children under the age of one per thousand live births. The rate ranges from as low as 3 (Singapore, Iceland) to as much as 150 (Sierra Leone, Afghanistan). The U.S. rate is just over 6. High infant mortality tends to result in higher fertility rates as families seek “insurance” for the loss of children.

50. Mortality Exceeds 100 in some LDC’s W. Europe < 5%
Generally a reflection of a country’s healthcare system

51. World Death Rates Infectious diseases Degenerative diseases
HIV/AIDS
SARS
Degenerative diseases
Obesity
Tobacco use
Epidemiological transition
Communicable diseases/pathogens in less developed countries
Degenerative diseases in more developed countries (obesity, heart disease, diabetes, cancer)

52. Adults and Children Living with HIV/AIDS, mid-2006

53. Epidemiologic Transition
Stages 1 and 2
Infectious and parasitic disease.
“natural checks” according to Malthus
Stages 3 and 4
Degenerative and human created disease.
Increase in chronic disorders associated with aging (heart attack, etc)
Possible Stage 5
Reemergence of infectious and parasitic disease.

54. Life Expectancy
Average number of years a newborn infant can expect to live at current mortality levels
W. Europe = late 70’s
Sub Saharan Africa = Late 30’s

55. Life Expectancy

56. Doubling Time World = 50 MDC = 550 LDC = 40 Honduras = 22
How long will it take for a population of a
given area to double in size?
• Doubling time assumes the population will
grow at a given annual rate
• Approximated by dividing the annual rate
of population into 72
World = 50
MDC = 550
LDC = 40
Honduras = 22
Denmark = 700
Russia = never?
Example: Bangladesh
72/R.N.I. => 72/2.09 = 34.4 years
Bangladesh with a population of million people in 2005 will have approximately 288.6
million people in 2039, if the population continues to grow at current rates.

58. The Demographic Transition Model

59. The Demographic Transition Model
Model that shows changes in natural increase, fertility, and mortality rates
A process with several stages

60. Demographic Transition Model
The demographic transition consists of four stages, which move from high birth and death rates, to declines first in death rates then in birth rates, and finally to a stage of low birth and death rates. Population growth is most rapid in the second stage.

61. The Demographic Transition Model
Every country in the world is in one of the stages
The process has a beginning, middle, and end
Once a country moves to a stage it does not revert back

62. Demographic Transition Model

63. The Demographic Transition
1. Low growth – 4. Low growth
2. High growth – 5. Negative growth?
3. Moderate growth
Population pyramids
Age distribution
Sex ratio
Countries in different stages of demographic transition
Demographic transition and world population growth

64. Demographic Transition Model
Stage one
Crude birth/death rate high
Fragile population
Stage two
Lower death rates
Infant mortality rate
Natural increase high
Stage three
Indicative of richer developed countries
Higher standards of living/education
Stage Four
CBR and CDR are at equilibrium or almost =
ZPG= Zero Pop. Growth
Most Northern and Western Euro countries

65. Stage/Phase 1: Low Growth (Pre-Industrial)
Most of human occupancy of Earth occurred in Stage 1
CBR and CDR would rise and fall but typically stayed at very high levels

66. Stage/Phase 1: Low Growth (Pre-Industrial)
Therefore the natural increase was virtually zero
Population remained unchanged (around 500,000)

67. Stage/Phase 1: Low Growth (Pre-Industrial)
Between 800 B.C. and 1750 AD population jumped from 5Million to 800 Million thanks to agricultural revolution

68. Stage/Phase 1: Low Growth (Pre-Industrial)
Humans remained at Stage 1 because of the unpredictability of the food supply
No Country is currently in Stage 1

69. Human Numbers Through Time: A.D. 0
2,000 years ago at the dawn of the first millennium A.D. the world's population was around 300 million people.

70. Human Numbers Through Time: A.D. 1000
1,000 years later the population had risen by as little as 10 million. And well into the second millennium, it grew less than 0.1 percent each year. The numbers in Europe even fell in the 1300s—struck down by the Black Plague. But beginning in the late 18th century, the Industrial Revolution would raise living standards and spur growth.

71. Stage/Phase 2: High Growth (Beginning of Industrial)
Around 1750 the natural increase jumped from .05% to .5%
Caused by several countries moving into Stage 2

72. Stage/Phase 2: High Growth (Beginning of Industrial)
In Stage 2 the CDR suddenly plummets while the CBR remains at roughly the same level (high)
Causes a High Natural Increase = rapid population growth

73. Stage/Phase 2: High Growth (Beginning of Industrialism)
Cause of drop in CDR was the Industrial Revolution (made life better/easier)
1800 in Europe and N. America

74. Stage/Phase 2: High Growth (Beginning of Industrialism)
1950 in Africa, Asia, and Latin America
Other countries moved into Stage 2 quicker because of the late 20th Century Medical Revolutions that were implanted into the LDC’s
LDC’s were given “Death Control”
Edward Jenner 1796: Smallpox vaccine

75. Human Numbers Through Time: 1800
800 years later the population had climbed to the landmark level of one billion people. Almost 65 percent of all people lived in Asia, 21 percent in a prospering Europe, and less than 1 percent in North America.

76. Stage/Phase 3: Moderate Growth (Industrialization Complete)
Movement from Stage 2 to Stage 3 occurs when the CBR begins to drop sharply
CDR is still dropping but not as sharply as CBR
Pop. Still grows – just at a modest rate
Europe and North America Enter 1st Half 20th Century
Asia, Latin America in recent years, Africa – Not yet

77. What causes the Crude Birth Rate to Drop?
Change in Social Customs
People choose to have fewer children
Parents understand the decline in mortality rates
More service jobs, less farming jobs
In urban areas children are not economic assets
Urban homes are smaller

78. Stage/Phase 4: Low Growth (Post-Industrial)
CBR = CDR = Natural Increase of 0 (called zero population growth ZPG)
Can still occur when CBR is higher than CDR because some women die before reaching childbearing years
Total Fertility Rate (TFR) 2.1 = ZPG

79. Demographic Transition Model
Women worldwide are having fewer children in their lifetimes, from an average of five children born per woman in the 1950s to below three in 2000.
All of the most recent projections put forth by the UN assume that levels of childbearing will continue to decline in the next century.
Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998).

80. Why such a low Fertility Rate in Stage/Phase 4?
Women in Stage 4 work
Childcare is needed in order to work
Birth control
Upscale Activities

81. Stage/Phase 4/5 in other Countries
Eastern Europe (especially Russia)
Negative Natural Increase
High Death Rates: poor pollution controls during communist control
Low Birth Rates
“Family Planning” remains from communism
In Russia women average 3.5 abortions
Pessimism about the future

82. To Review…

83. Stage One Pre-industrial
CBR and CDR high and fluctuate according to natural events and disasters.
Population is a constant and young pop.

84. Stage Two
Death rates drop… improvements in food supply, sanitation, etc.
Birth rates do not drop… causes an imbalance so there is a large increase in population.

85. Stage Three Birth rates fall Population growth begins to level off
Access to contraception
Increase in wages
Urbanization
Move away from subsistence agriculture.
Education of women
Population growth begins to level off

86. Stage Four Low birth AND low death.
Birth rates may drop below replacement levels (Japan and Italy) which may lead to negative population growth (Stage 5?).
Large group born during stage 2 ages… creates a burden on the smaller working population.

87. Soooo…. A cycle, in a way, from 1 to 4
Difference= in Stage 1 CBR and CDR are high… in Stage 4 they are low.
Difference= total population of a country is higher in Stage 4 than in Stage 1

88. The Demographic Transition in England
Now Stage 4
Historically
Stage 1 – Low growth until 1750
Stage 2 – High growth
Stage 3 – Moderate growth 1880-early 1970’s
Stage 4 – Early 1970’s-present. Long time below the 2.1 Total Fertility Rate needed for replacement.

89. Problems with the Demographic Transition Model
based on European experience, assumes all countries will progress to complete industrialization
many countries reducing growth rate dramatically without increase in wealth
on the other hand, some countries “stuck” in stage 2 or stage 3
it is not an exact science!!!!!!!!

90. Remember… Demographic Transition is not only dependent on CBR and CDR but also on in and out migration!!!!

91. If we are in Stage 4 then why is world population increasing at such a rapid rate?

92. Demographic Transition and World Population Growth
Second Half of the 20th Century population increase rapidly because few countries were in Stage 1 or 4
Today no country is in Stage 1 and few are in Stage 4
Most countries are Stage 2 or 3, many countries won’t reach Stage 4 any time soon

93. Demographic Transition and World Population Growth
Stage 4 is caused by 2 “breaks”
Drop in the Crude Death Rate
Drop in the Crude Birth Rate
N. America and Europe created their first break by creating the Industrial Revolution
Therefore society had gradually moved to that point both socially and economically

94. Demographic Transition and World Population Growth
However the first break was artificially implanted into many other countries
The Regions of Africa, Parts of East Asia, and others were given the ability to lower their Crude Death Rate
This caused a massive change in population without the change in societal structure that came in Europe and North America that would eventually cause the Drop in the Crude Birth Rate

95. Causes for drop in Crude Birth Rate
Change in Social Customs
People choose to have fewer children
Parents understand the decline in mortality rates
More service jobs, less farming jobs
In urban areas children are not economic assets
Urban homes are smaller
Women work
Birth Control
Does it Seem like these Changes in Social Customs are occurring in the countries that are currently in Stage 2?

96. Answer
Only Europe, Australia and Parts of Asia and North America are in Stage 4
Other areas with already large population centers are in Stage 2 or Stage 3
The problem lies in how to encourage those areas to reach Stage 4 (P.S. – Why is staying in Stage 2 or Stage 3 a “problem?”)

98. Warm-Up: 9/20 How do the crude birth rate & the fertility rate differ?
Why do some analysts criticize the applicability of the DTM to all parts of the world?

99. Warm-Up: 9/20
What types of geographic questions can be answered by studying a population’s age and gender composition?

100. Population Pyramids & the Demographic Transition Model

101. Population in Demographic Transition
A country’s stage in Demographic Transition gives it a distinctive population structure
The Demographic Transition Influences population structure in 2 main ways:
% of population in Each Age Group
Distribution of males and females
We can visually see these influences by using Population Pyramids

103. Population Pyramid (Age/Sex Pyramid)
Bar graphs displayed both horizontally and vertically showing variations within particular subgroups or a population with respect to certain descriptive aspects, such as birth or deaths
Population pyramids are typically a representation of the population based on its composition according to sex and age

104. Characteristics of Population Pyramids
Males = left side of the vertical axis
Females = right side of the vertical axis
Age = order sequentially with youngest at the bottom and oldest at the top
Pyramid allows demographers to identify changes in the age sex composition of a population

105. Population Pyramid Developed Countries
A country in stage 4 of the Demographic Transition Model
Large number of “older people”
Smaller % of young people

106. Population Pyramid Developing Countries
A country in stage 2 of the Demographic Transition Model
Large number of young people and a smaller older population

107. Rapid Growth in Cape Verde
Cape Verde, which entered stage 2 of the demographic transition in about 1950, is experiencing rapid population growth. Its population history reflects the impacts of famines and out-migration.

108. Moderate Growth in Chile
Chile entered stage 2 of the demographic transition in the 1930s, and it entered stage 3 in the 1960s.

109. Age Distribution
Dependency Ratio: number of people who are too young or too old to work, compared to the number of people in their productive years

110. Sex Ratio
Sex Ratio: number of males per hundred females
In general more males are born than females
Males have higher death rates

111. 3 age groupings 0-14 = Dependents 15-64 = Workers 64+ = Dependents
Stage 2 Countries = 1:1
Stage 4 Countries = 1:2

112. Sex Ratio
Europe and North America = 95:100
Rest of World = 102:100

113. Developing Countries
Have large % of young people –where males generally outnumber females
Lower % of older people – where females are typically more numerous
High immigration = more males

119. Population Shift

120. An Aging World Discussion
What are the implications of an aging population for:
The U.S. housing market?
Social security and pension funds?
Public financing of colleges and universities?
Global migration flows?

121. OVERPOPULATION!!!

122. Overpopulation
When consumption of natural resources by people outstrip the ability of a natural region to replace those natural resources.

124. Thomas Malthus An Essay on the Principle of Population (1798)
Earth’s population was growing much more rapidly than the Earth’s food supply

125. Thomas Malthus on Population
Malthus predicted:
population would outrun food supply
decrease in food per person.
Assumptions
Populations grow exponentially.
Food supply grows arithmetically.
Food shortages and chaos inevitable.

126. Reason… Population increases geometrically
Food Supply increases arithmetically

127. Population J-Curve

128. Reasoning…
Made prediction following England’s entrance into stage 2 of DT
Moral restraint needed to lower CBR or something needs to increase the CDR

129. Neo-Malthusians
Problem of overpopulation will be even worse than Malthus predicted

130. 2 Main Reasons
Malthus failed to anticipate how many LDC’s would reach stage 2
Overpopulation outstrips more than just food production

131. Population and Resource Consumption

132. Technology, Energy Consumption, and Environmental Impact
There has been a dramatic increase in:
individual energy use over time: 3,000 kcal/person - 300,000 kcal/person
the power of technology to change the environment: think stone axe versus bulldozer versus atomic bomb.
The scope and severity of environmental impacts.

133. Population and the Environment
I = P x A x T
Impact = Population x Affluence x Technology
Population-influenced environmental problems:
Global Warming
Habitat Loss / Endangered Species
Resource Depletion
Food Shortages? Not globally, but regionally.

134. Criticism of Malthus
Assumed world resources are fixed rather than expanding
Increased pop. could create more resources
Marxist argument that there are plenty of resources only an unequal distribution

135. Jean Antoine Condorcet
(1743 – 1794)
predicted that innovation, resulting increased wealth, and choice would provide food and resources in the future and lead to fewer children per family
believed that society was perfectible

136. Malthus and Reality
Last half-century has not supported Malthus’s theory
Food production & effects of globalization

137. Consistent drop in the NIR Caused by a drop in the CBR
Malthus and Reality
Cultural and societal changes moved societies into stages 3 and 4 quicker
Consistent drop in the NIR
Caused by a drop in the CBR
Economic Development
Contraceptives