2. Icebreaker – Imagining Billions
Q1: The equator stretches approx. 25,000 miles
around Earth. If each of the world’s 6.8 billion
people was allotted 1 yard of space. How many
times would the current human population circle
the globe? (Hint: 1,760 yards = 1 mile)
Q2: If a human, beginning at birth, started to count
to world’s population. How many years would it
take him to count all 6.8 billion people? (Note:
For each second he/she would count one
person)
3. Key Issues
1.) Where is the world’s population distributed?
2.) Where has the world’s population increased?
3.) Why is overpopulation increasing at different rates
in different countries?
4.) Why might the world face an overpopulation
problem?
5. Distribution of World’s Population
• Population Concentrations
- Four Large Population Clusters
- Other Clusters
• Sparsely Populated Regions
- Physical Environments
• Population Density
- Arithmetic Density
- Physiological Density
- Agricultural Density
6. Population Cartogram – Countries displayed by size of population rather than land
area. Countries named on map have at least 50 million inhabitants.
7. - 4 Population Clusters: East Asia, South Asia, Southeast Asia, and Western Europe
- 2/3 of World’s Inhabitants live within one of these four regions
- China is world’s most populous country at 1.3 Billion People
- China & India contain 30% of the World’s Population!!!!!
8. How does physical
environment impact
where people live?
Ecumene – Portion
of Earth’s surface
occupied by
permanent human
settlement
Has ecumene
increased or
decreased
throughout the
years?
10. Population Density
• Arithmetic Density – Total number of people
divided by total land area.
• Physiological Density – Number of people
supported by a unit of arable land.
• Agricultural Density – Ratio of number of
farmers to amount of arable land.
11. Arithmetic Density
What is
odd
About
Russia?
-Population / Land Area = Arithmetic Density (Population Density)
-Brazil 200,000,000 / 8,500,000 = 23.5 Arithmetic Density (23.5 persons per square
kilometer
-Measures how densely or sparsely populated a region is
12. Physiological Density
-The higher the physiological density, the greater pressure that people may place on
the land to produce enough food
-Egypt has an arithmetic density of 75, but physiological density is 2,580…..why???
-95% of population lives within Nile River Valley (small area)
13. Distribution of World Population Growth
• Natural Increase Rate
– CBR (Crude Birth Rate)
– CDR (Crude Death Rate)
• Fertility
– TFR (Total Fertility Rate)
• Mortality
– IMR (Infant Mortality Rate)
– Life Expectancy
14. Natural Increase Rate (NIR)
-Current NIR in world is 1.2, meaning population of world is growing 1.2% each year
-1.2% of 6.5 billion is approx. 80 million (equivalent to pop. of Germany)
-Increase of the NIR to 2% would result in world pop. increasing 132 million each year
-Majority of natural increase is occurring in LDCs (Less Developed Countries)
-Less resources in LDCs mean it’s harder to maintain population
15. Total Fertility Rates (TFR)
-Avg. number of children a woman will have in her childbearing years (15-49)
-Varies significantly between MDCs and LDCs
-All European nations below 2.0
-China controlling TFR by issuing 1-child policy
16. Infant Mortality Rates (IMR)
-Number of deaths of infants under 1 year of age
-Reflects a country’s health care system
-Varies significantly between MDCs and LDCs
17. Crude Death Rate (CDR)
-Total number of deaths per 1,000 people/per year
-Why does Denmark (one of world’s wealthiest countries) have a higher CDR than
Mongolia (one of the poorest)?
-How can the U.S. have a higher CDR than Saudi Arabia?
18. The Demographic Transition
Population process with four stages, and every country
is in one of them. Process has beginning, middle,
and end, and is not irreversible. Also, countries do
not revert to an earlier stage
Stage 1: Low Growth
Stage 2: High Growth
Stage 3: Moderate Growth
Stage 4: Low Growth
19. The Demographic Transition
Q1: In what stage does greatest population increase occur?
Q2: What stage is the United States currently in? Explain.
Q3: Why would CBR be continually decreasing?
20. Demographic Transition
• Stage 1: 8000 B.C.E. to 1750 C.E. – food supplies and
farming unpredictable, thus CBR and CDR fluctuated
frequently
• Stage 2: CDR decreases, while CBR remains the
same. Industrial Revolution helped farmers increase
food production.
• Stage 3: CBR decreases, while CDR continues to
decrease. Economic changes cause people to have
less offspring.
• Stage 4: CBR equals CDR….condition called Zero
Population Growth (ZPG)
ALL COUNTRIES ARE SOMEWHERE BETWEEN STAGE 2 & STAGE 4
21. Demographic Transition Example
Death rates decrease
due to increase in food
production
Economic changes cause
people to have less kids
ENGLAND
If CBR and CDR are equal in Stage 4, why would population still be increasing?
22. Population Pyramids
Population in a country is
influenced by the
demographic transition in
2 ways: percentage of
population in each age
group and distribution of
males and females
POP. PYRAMIDS
-Age Distribution
a.) 0-14 (Dependent)
b.)14-65
c.) 65+ (Dependent)
-Sex Ratio
Dependency Ratio:
Number of dependents
(too young or old to work)
compared to number of
people in productive yrs.
24. Will World Face an Overpopulation
Problem?
• Thomas Malthus on Overpopulation
- Malthus’s Theory
- Malthus Critics
• Declining Birth Rates
- Malthus Theory vs. Reality
- Reasons for Decline
• World Health Threats
- Epidemiological Transition Stages
25. Malthus’s Theory vs. Reality
Food & Population 1950-2000
-Malthus predicted population would
grow faster than food production, but
food production actually expanded
faster than population in the 2nd half of
the 20th century.
-Malthus was fairly close on food
production, but too pessimistic on
population growth
-Although world as a whole may not be
in danger of “running out” of food,
some regions with rapid growth do face
shortages of food
-Example: Eastern Africa grew by 2%
economically per year since 1980, but
population grew by 3% per year. Result
= East Africa is worse today than 10,
20, 30 years ago
-Malthus did not account for decreasing
CBR
26. Decline of CBR
-CBR has continued to decline over the past few decades
-However, CDR continues to decline in the world as well – thus world population
continues to increase