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Chapter 2Population
Understanding population is crucial: More people alive now than at any other time Increased faster rate in last ½ of 20th century than
any other time All global population growth is in LDCs
Key Issue 1: Where is the World’s Population Distributed?
East Asia ¼ of world population with 5/6 in China
South Asia ¼ of world’s population; India has ¾ of them
Southeast Asia 4th largest; 600 million
Europe 1/9 of world’s population; 3rd largest
Other includes: Northeastern US and Southeastern Canada
Population Concentrations
VOCAB WORD: ECUMENE: portion of Earth’s surface occupied by permanent human settlement
People don’t cluster in certain environments Too dry, too cold, too wet, too high
Places that are too harsh have reduced over time ¾ of population live on 5% of Earth’s surface
Sparsely Populated
Arithmetic Density Total # of objects in an area
Physiological Density # of people supported by a unit area of arable land
Ex: US has 453 people per square mile vs Egypt with 5,947 per square mile.
Higher the physiological density, the greater the pressure that is placed on land to produce enough food
Agricultural Density Ratio of the number of farmers to the amount of arable land MDCs have LOW agricultural density because of tech and $$ (less
people for more land/food)
Population Density
Geographers measure growth in 3 ways Crude Birth Rate:
CBR: total # of live births a year per 1,000 people Crude Death Rate:
CDR: total # of deaths in a year per 1,000 people Natural Increase Rate:
NIR: % by which a population grows in a year Affects doubling time: # of yrs needed to double
population Convert CDR/CBR to % (# per 100) Subtract CDR from CBR Ex: CBR = 20; CDR = 5, NIR = 15 per 1,000 or 1.5%
Key Issue 2: Where has the World’s Population Increased?
Total Fertility Rate: TFR Measure the # of births in a society Average # of children a woman will have in
childbearing years Mortality
Infant mortality rate Annual number of deaths of infants under 1 year of age
compared to live births Life Expectancy
At birth measures the average # of years a newborn can expect to live at current mortality levels
More Measures
Demographic Transition Model: Process of change among different countries at varying
rates 4 stages, potentially 5 Stage 1: Low Growth
High birth and death rate; no long term NIR Stage 2: High Growth
Rapid decline death rate; very high birth rate, very high NIR Stage 3: Moderate Growth
Rapid decline birth rate; decline death rate; moderate NIR Stage 4: Low Growth
Very low birth and death rate; no long term NIR
Key Issue 3: Why is Population Increasing at
Different Rates in Different Countries?
Growth caused by agricultural revolution (8000 BC)
Humans began to farm Not sole reliance on hunting/gathering
Stage 1
1: High Stationary
Few remote groups
High Birth/Death Rate
Stable or slow NIR
Many children needed for farming; Children die at early age
Religious/Social encouragement; No family planning
Disease, famine, Poor medical understanding
10,000 after Ag Rev, population grew modestly Burst of growth in Late 18th and early 19th
centuries 1750 many entered Stage 2 due to Industrial
Revolution Major improvements in industrial tech, hygiene Africa, Asia, Latin America in 20th century-stage 2,
due to medical revolution
Stage 2
Stage 2: Early Expanding
Egypt, Kenya, India
High Birth; rapid falling Death; very rapid rise NIR
Many children help farm; children die at early age
Religious/social encouragement; no family planning
Improvements in medical care, water supply and sanitation
Fewer children die
Country’s CBR begins to drop rapidly, CDR falls but slower than in Stage 2
CBR drop due to social customs changes Fewer children Economic changes Live in cities instead of country Less working on farms
Stage 3
Stage 3: Late expanding
Brazil
Falling birth, death falls more slow, NIR slows down
Improved medical care and diet, Fewer children needed
Improvements in medical care, water supply, sanitation
Fewer children die
CBR declines to being equal with CDR; NIR = 0 Called Zero Population Growth (ZPG) Social changes Women working outside home Urban societies, higher medical knowledge
Stage 4
Stage 4: Low stationary
USA Japan France UK
Low birth/death, stable/slow NIR
Family planning, good health, improved status of women
Late marriages
Good health care, reliable food supply
Many stage 4 could be headed to 5 Indicators: Very low birth, low death, slow
decrease in total population Birth rate lowest ever experienced since Stone
Age Developed countries total population declining What might it look like?
Women empowerment- career above children Long life expectancy
Possible Stage 5?
Bar graph showing country’s population displayed by age and gender
Shows percentage of total population in 5 year age groups, starting with 0-4 years old and ending with 80+ or 90+
Pyramid can tell a lot about countries’ character.
Most important factor: Dependency ratio: # of people who are too young/old to work compared to the # of people in their productive years
Sex Ratio: # of males per 100 females in population
Population Pyramids
Thomas Malthus: argued world’s rate of population increase was surpassing development of food supplies ( 1798)
Population increased geometrically; food supply increased arithmetically
Some believe still relevant today: LDC food production expands, but more poor than before Outstripping of resources due to world population growth
Critics say Resources aren’t fixed, they expand Large population can raise economic growth
Key Issue 4: Why might the world face an
overpopulation problem?
On the whole, not running out of food Some regions may have food shortages CBR has declined in LDC from 31 to 23 since
1990 2 reasons for lower CBR
Improved economic conditions Diffusing modern contraceptive methods,
providing resources in LDCs
Declining Birth Rates
Distinctive causes of death in stages of DTM Stages 1 and 2:
Stage 1: Stage of pestilence and famine Black Plague (stage 1) aka bubonic plague Stage 2: receding pandemics: Cholera was an epidemic
Stages 3 and 4: degenerative and human created diseases Decrease in death of infectious disease, increase in
chronic associated w/aging Cancer, heart attacks 4: delayed degenerative diseases
Cancer still exists, medical advances allows longer life
Epidemiologic Transition
Reemergence of infectious and parasitic diseases Higher CDRs 3 reasons for reemergence:
Evolution Microbes have evolved and changed building
resistance to drugs Poverty
Expensive treatment results in no treatment Improved Travel
Diseases diffuse as people travel, exposing others to diseases.
Possible Stage 5