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