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 populationCrude 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 areaIncludes food, water, and shelter

Carrying capacity: the ability of the land to sustain a certain number of organismsOverpopulation occurs when the population

exceeds the carrying capacityHabitable 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 productivityMalthus 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 rateLinear Growth: the population increases by ten every

yearExponential growth: the population increases by 10 the

first year, 11 the second year, and so onAfter ten years, the first village would have 200. The

second village would have 234.

Criticisms of MalthusMalthus was correct about the population

growth, but not the agricultural productionNew inventions and technology increased

productivityThe world currently can produce enough food to

feed itselfneo-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 countryUS 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 stagesEvery country goes through each stage,

and does not regress, unless disaster occurs

Stage 1: Hunting and Gathering

Society has a low populationHigh Birth RateHigh Death RatePopulation growth determined by food

supplyWhen food abundant, people have more

childrenWhen food scarce, people abstain

Examples: Aborigines of Australia

Stage 2: Agricultural Society

Rapid population growth occursBirth rates stay highDeath rates decline sharply due to food

sources and better medical careThe majority of the population is involved

in farming; mainly subsistenceBasic technologyChildren seen as security

Example: Liberia

Stage 3: Industrial Society

Population growth still grows, but not as rapidly as in stage 2

Birth rates declineDeath rates declineIndustrial Revolution: began in the mid-

1700’s in Europe that allowed many countries to adopt mechanized system of farmingChildren become liability instead of asset

Example: Bolivia

Stage 4: Tertiary Societies

Characterized by zero-population growthBirth rates equal death ratesSociety moves from industry to service

based societyNatural Increase Rate is at or below 2Some countries are experiencing negative

population growthExample: 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