APHG Unit Two Review
Population
Intro to Population
The world’s population is currently greater
than 6.5 billion people
Population has been increasing for as long
as humans have been on the planet
During the last 100 years, the world’s
population has exploded
Population Explosion: a crisis in some
LDC’s where the country’s resources
cannot support the growing population
Demography
The study of population characteristics is
called demography
Demographic statistics include:
Crude Birth Rate: the number of live births per
1,000 people in the population
Crude Death Rate: the number of deaths per
1,000 people in the population
Overpopulation
Overpopulation is defined as the lack of
necessary resources to meet the needs of
the population of a defined area
Includes food, water, and shelter
Carrying capacity: the ability of the land to
sustain a certain number of organisms
Overpopulation occurs when the population
exceeds the carrying capacity
Habitable land is called ecumene
The Five Too’s…again
People tend not to live in areas where it is
too hot, too cold, too hilly (two), too wet, or
too dry
Because of this, humans occupy a small
part of the planet
Underpopulation
Some parts of the world are
underpopulated
Underpopulation occurs when an area is
sparsely populated and dominated by
agriculture
Example: Midwest
Population Density
Arithmetic Density:
divides the population by
land area; also called
population density
Physiological Density:
divides the total
population by the land
used by humans
Agricultural Density: the
number of farmers
divided by the amount of
arable land
Malthus
Thomas Malthus was a British economist
who wrote in the late 1700’s
He claimed that the rate of population was
growing at a faster rate than food
productivity
Malthus was first to use the term overpopulation
His concern was that population was
growing at exponential rate, and
agricultural production was growing at
linear rate
Types of Growth
Linear Growth: growth that occurs evenly
across each unit of time
Exponential Growth: growth as a percentage of
the total population
Example: Imagine a village with 100 people with
a 10 percent growth rate
Linear Growth: the population increases by ten every
year
Exponential growth: the population increases by 10 the
first year, 11 the second year, and so on
After ten years, the first village would have 200. The
second village would have 234.
Criticisms of Malthus
Malthus was correct about the population
growth, but not the agricultural production
New inventions and technology increased
productivity
The world currently can produce enough food to
feed itself
neo-Malthusians: the theory that if there are
multiple minority groups and no majority groups
in a population, the growth rate will eventually
resemble the growth rate of the fastest-growing
group within the country
US will have exponential growth due to immigration
Demographic Transition Model
Indicator of what will happen to a society
or country’s population
Based on three factors: the birth rate, the
death rate, and the total population
Has four or five stages
Every country goes through each stage,
and does not regress, unless disaster
occurs
Stage 1: Hunting and Gathering
Society has a low population
High Birth Rate
High Death Rate
Population growth determined by food
supply
When food abundant, people have more
children
When food scarce, people abstain
Examples: Aborigines of Australia
Stage 2: Agricultural Society
Rapid population growth occurs
Birth rates stay high
Death rates decline sharply due to food
sources and better medical care
The majority of the population is involved
in farming; mainly subsistence
Basic technology
Children seen as security
Example: Liberia
Stage 3: Industrial Society
Population growth still grows, but not as
rapidly as in stage 2
Birth rates decline
Death rates decline
Industrial Revolution: began in the mid-
1700’s in Europe that allowed many
countries to adopt mechanized system of
farming
Children become liability instead of asset
Example: Bolivia
Stage 4: Tertiary Societies
Characterized by zero-population growth
Birth rates equal death rates
Society moves from industry to service
based society
Natural Increase Rate is at or below 2
Some countries are experiencing negative
population growth
Example: Germany and Japan
More population statistics:
Infant Mortality Rate: the number of babies
per 1,000 that die before their first birthday
Total Fertility Rate: the number of babies
the average woman delivers during her
childbearing years
Population Distributions
Demography is not only about the
population numbers, but about the
characteristics of the population itself
Sex ratio: the number of males compared
to females in a population
Population Pyramid: a visual
representation of a country’s population
High, Slow & Negative Growth
Population Structure
Population projections: make predictions
of future populations
Dependency Ratio: the number of people
aged 0-14 or over 65 that rely on other
people to take care of them
Demographic momentum: a continued
population increase as a result of a large
segment of the population being young
More stats…
Demographic Equation: the global births
minus the global deaths and determines
population growth for the world
Doubling Time: the amount of time it will
take the population to double in size
Sustainability: saving resources for future
generations so that they can live at the
same or higher standard than people living
today
Curves:
J-Curve: developed by Ian Bremmer;
places countries on a scale determined by
their openness and stability; graphically
illustrates the population explosion
S-Curve: looks at population growth along
the Demographic Transition Model
Population J-Curve
Population Increase:
Medical Advances: New medicines and
inoculations; disease diffusion does not occur as
frequently as it used to
Quantity and Quality of Food: increases in
Agricultural technology have increased food
supply
Ethnic and Religious Issues: Birth control is
forbidden in some religions
Economic Issues: Population increases in
agricultural society, and decreases in tertiary
societies
Population Decreases
Natural Disasters: Earthquakes, famines,
and plagues can wipe out a large
percentage of the population
War or Political Turmoil: death by war and
refugees
Economic Issues: main reason people
migrate is for economic opportunities