The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Objectives
• Describe how the size and growth rate of the human population has
changed in the last 200 years.
• Define four properties that scientists use to predict population sizes.
• Make predictions about population trends based on age structure.
• Describe the four stages of the demographic transition.
• Explain why different countries may be at different stages of the
demographic transition.
• Describe three problems caused by rapid human population growth.
• Compare population growth problems in more-developed countries and
less developed countries.
• Analyze strategies countries may use to reduce their population growth.
• Describe worldwide population projections into the next century.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
National Science Education Standards
Content Standard F – Population Growth
• Populations grow or decline through the combined effects of births and deaths, and
through emigration and immigration. Populations can increase through linear or
exponential growth, with effects on resource use and environmental pollution.
• Various factors influence birth rates and fertility rates, such as average levels of
affluence and education, importance of children in the labor force, education and
employment of women, infant mortality rates, costs of raising children, availability and
reliability of birth control methods, and religious beliefs and cultural norms that
influence personal decisions about family size.
• Populations can reach limits to growth. Carrying capacity is the maximum number of
individuals that can be supported in a given environment. The limitation is not the
availability of space, but the number of people in relation to resources and the capacity
of earth systems to support human beings. Changes in technology can cause significant
changes, either positive or negative, in carrying capacity.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Key Terms
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Demography
Age Structure
Survivorship
Fertility Rate
Migration
Life Expectancy
Demographic Transition
Infrastructure
Arable Land
Urbanization
Least Developed Countries
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Focus Questions
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2.
3.
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7.
8.
Describe how the size and growth rate of the human population has
changed in the last 200 years.
Define four properties that scientists use to predict population sizes.
Explain what we can predict about a population’s likely growth rates
based on its current age structure.
Describe the four stages of the demographic transition.
Explain why the oldest people in a population may be much older than
the average life expectancy.
Describe three problems caused by rapid human population growth.
Compare the population growth in more-developed countries to
population growth in less developed countries.
Describe worldwide population projections for the next 50 years.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Demography is the study of the characteristics of populations,
especially human populations.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Human Population Over Time
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Human Population Over Time
In the past 200 years, the population has increased from about 1
billion to over 6 billion and the growth rate has increased. This
change was made possible by improvements in:
1. Healthcare
2. Nutrition
3. Sanitation
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size
Scientists use the following four properties to predict population
sizes:
1.
2.
3.
4.
Age Structure
Survivorship
Fertility Rates
Migration
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Age Structure
Age structure is the classification of members of a population
into groups according to age or the distribution of members of a
population in terms of age groups.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Age Structure
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Age Structure
What can we predict about a population’s likely growth rates
based on its current age structure?
If a population has more young people than older people, the
population size will probably increase as the young people grow
up and have children.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Survivorship
Survivorship is the percentage of newborn individuals in a
population that can be expected to survive to a given age.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Survivorship
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Fertility Rates
Fertility rate is the number of births (usually per year) per 1000
women of childbearing age (usually 15 to 44).
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Fertility Rates
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Migration
Migration is any movement of individuals or populations from
one location to another; specifically, a periodic group movement
that is characteristic of a given population or species.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Forecasting Population Size – Migration
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Declining Death Rates
Life expectancy is increasing!
Life expectancy is the average length of time that an individual is
expected to live.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Declining Death Rates
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Declining Death Rates
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Declining Death Rates
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Declining Death Rates
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Declining Death Rates
Life expectancy is sometimes deceptive.
The oldest people in a population may be much older than the
average life expectancy.
Life expectancy is affected by infant mortality. If infant mortality
is high, it brings down life expectancy. Many people live past life
expectancy because the number is an average of all life spans.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition
The demographic transition is the general pattern of
demographic change from high birth and death rates to low birth
and death rates, as observed in the history of more-developed
countries.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – Stages of the Transition
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – Stages of the Transition
Four stages:
1. Stage 1 (Preindustrial) – Birth and death rates are high so the
population grows slowly or not at all.
2. Stage 2 (Transitional) – Birth rates remain high but death rates
decline as hygiene, nutrition, and education improve. The
population increases.
3. Stage 3 (Industrial) – Birth rates and death rates are about equal,
so the population stabilizes.
4. Stage 4 (Postindustrial) – Birth rates decline while the death rates
stay low, so the population decreases.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – How to decline birth rates…
Four significant factors that cause a decline in birth rate are:
1.
2.
3.
4.
Increased education for women
Increased economic independence for women
Increased cost per child
Increased availability of pensions for elderly people
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – How to decline birth rates…
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – How to decline birth rates…
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – How to decline birth rates…
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – How to decline birth rates…
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
The Demographic Transition – How to decline birth rates…
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Changing Population Trends
Rapid human population growth leads to serious problems.
A rapidly growing population uses resources at an increased rate
and can overwhelm the infrastructure of a community.
Infrastructure is the basic facilities of a country or region, such as
roads, bridges, and sewers.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Changing Population Trends - Infrastructure
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth
Three major problems associated with rapid human population
growth are:
1. Fuel Shortages
2. Unsafe Water
3. Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Fuel Shortages
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Fuel Shortages
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Unsafe Water
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
Negative impacts on land caused by rapid human population growth
include:
1. Shortage of Arable Land
Arable land is farmland that can be used to grow crops.
2. Urbanization
Urbanization is an increase in the ratio or density of people living in
urban areas rather than rural areas.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Problems of Rapid Growth – Impacts on Land
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World
Demographers have divided the world into two regions:
1. More Developed Countries – higher average incomes, slower
population growth, and diverse industrial economies.
2. Less Developed Countries – lower average incomes, rapid
population growth, and diverse industrial economies.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World – Least Developed Countries
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World – Least Developed Countries
Least developed countries are countries that have been
identified by the United Nations as showing the fewest signs of
development in terms of income, human resources, and
economic diversification.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
A Demographically Diverse World
Less developed countries typically have higher birth rates and
lower life expectancies than more developed countries.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Managing Development and Population Growth
The governments of some countries have tried to reduce birth
rates by employing the following strategies:
1.
2.
3.
4.
Public advertisements
Family planning programs
Economic incentives
Legal punishments
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Managing Development and Population Growth
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Managing Development and Population Growth
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Managing Development and Population Growth
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Managing Development and Population Growth
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Growth Is Slowing
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Growth Is Slowing
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Growth Is Slowing
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Growth Is Slowing
The worldwide population is expected to increase for the next 50
years and reach between 8 and 11 billion. The exact amount of
increase is uncertain.
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Will there be enough chairs for everyone?
The Human Population & Earth’s Carrying Capacity
A Real-Life Game of Musical Chairs
Will there be enough chairs for everyone?
HOMEWORK
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lecture notes, assessment data, assessment answer keys.
Study the readings for a formative quiz at the beginning of the next
class.
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