1. Chapter 2 Population

2. Key Issue 1: Where is the World’s Population Distributed? • 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

3. Population Concentrations • 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

4. Sparsely Populated • 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

5. Population Density • 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)

6. Key Issue 2: Where has the World’s Population Increased? • 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%

7. More Measures • 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

8. Key Issue 3: Why is Population Increasing at Different Rates in Different Countries? • 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

9. Stage 1 Growth caused by agricultural revolution (8000 BC) Humans began to farm Not sole reliance on hunting/gathering

10. Stage 2 • 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

11. Stage 3 • 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

12. Stage 4 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

13. Possible Stage 5? • 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

14. Population Pyramids 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

15. Key Issue 4: Why might the world face an overpopulation problem? • 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

16. Declining Birth Rates • 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

17. Epidemiologic Transition • 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

18. Possible Stage 5 • 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.