Download UNIT TWO: POPULATION

UNIT TWO: POPULATION

Population Intro 

Why important to study? • More people on earth than at any other time in history (6.5 bill) • World’s pop increased faster in second half of 20th C than ever before • Almost all global pop growth is occurring in LDCs…poorest countries growing fastest…in some cases leads to famine and human suffering • People are living longer – past 50 yrs global life expectancy has increased by 20 yrs

DEMOGRAPHY  

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Demography: study of human pop Most demographers agree world pop growth is slowing Project pop will plateau at @ 12 bill some time in 21st C Historically pop growth has been steady but certain events have checked it…..disease has been and continues to be biggest threat

2.1 Population Concentrations 

Ecumene: portion of earth’s surface occupied by permanent human settlement • ¾ world pop live on 5% of earth’s surface….Why?

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2/3 of world pop lives in 4 regions • 1.) EAST ASIA (E. China, Japan, Taiwan, Koreas  

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China has 20 large urban areas, but 2/3 pop is rural China = world #1 ¾ Japan and Korea = urban

4 Populous Regions - contd • 2.) SOUTH ASIA (India, Pakistan, Bangladesh, Sri Lanka)  

India = world #2 ¾ rural

• 3.) EUROPE – E and W…mostly urban • 4.) SE Asia (islands of Java, Sumatra, Borneo, Papua New Guinea, Philippines, Vietnam, Thailand)  

Indonesia = world #4 Mostly rural

Top 10 Populous Nations   

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1. 2. 3. 4. 5.

China India U.S.A. Indonesia Brazil

6. Pakistan 7. Russia 8. Bangladesh 9. Nigeria 10. Japan

• China and India expected to flip flop • U.S. will stay #3 b/c of immigration • LDCs taking top spots from MDCs

Population Density 

Arithmetic Density: total # of people divided by total area of land • Can be misleading b/c is an average • US = 78/sq mile, but Manhattan is 67,000/sq mile and Loving, TX .1/sq mile • Highest = Bangladesh, Japan, Netherlands • Remember high pop (China) not necessarily high pop density

Pop Density cont’d 

Physiological Density: ratio of people to a given unit of cultivable/arable land (suited for agriculture) • i.e. can you feed your population? • Can be high b/c of high pop density or poor land • Ex: US 404/sq mile of arable land Egypt 9,073/sq mile of arable land

2.2 POPULATION GROWTH 

Rule of Thumb…. • Pop increases rapidly where many more born than die • Slowly where births barely exceed deaths • Decreases where deaths outnumber births • Increases when people move in and decreases when people move out

Pop Change…measured 3 ways 

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1. Crude Birth Rate CBR: total # of births for every 1,000 alive 2. Total Fertility Rate TFR: average # of children a woman will have during child bearing yrs. Affected by: culture, religion, lifestyle, is child econ asset or drain, access to birth control, mother’s educ and career

Pop Change – cont’d. 

3. Natural Increase Rate NIR: • • • • • • •

NIR = CBR – CDR Calculates % by which pop grows each yr. Ex: CBR = 20, CDR = 5, NIR = 1.5% Excludes migration – only natural increase A negative NIR means pop decreasing World NIR peaked in 1963 at 2.2% World NIR has declined in last 20 yrs.

What determines a nation’s NIR? Factors to consider   

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Econ development Education Gender Empowerment – status and power to women Health Care Culture (i.e. Catholics or Mormons) Public Policy (ex: China one child)

Factors determining a nation’s NIR – cont’d. 

Conclusions….countries w/ low econ development, low educ, low gender empowerment, but w/ lower infant mortality rates b/c of improved health care, cultural traditions favoring fertility, and no public policy limiting pop growth..have HIGHEST rates

Where are these countries? 

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LDCs: sub Sahara Africa, parts of Middle East, parts of L. America In MDCs pop growth is not natural but due to immigration Irony – fastest growing places are least equip to deal w/ the growth

Doubling Time 

Doubling Time: # of yrs needed for a pop to double • Formula 70/NIR…ex: NIR is 2.6 % DT is 70/2.6 = 27 years • Pop growth is compounded/exponential (if rate stays steady at 3% you’ll add more raw numbers each yr b/c base gets bigger) • At 3% rate, DT is less than 25 yrs. Taking place in SS Africa, parts of ME, and parts of Central America

MORTALITY 

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CDR Infant Mortality Rate: annual # of deaths of infants under 1 yr compared w/ total # of births • In some parts of SS Africa is 10%

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Life Expectancy: # or yrs a newborn can expect to live..75 in most MDCs, late 30s in some parts of Africa

Population Growth Curves 

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S Curve – historical growth J Curve – exponential growth (fixed percentage)

Demographic Momentum 

The tendency for pop growth to continue despite strict family planning b/c of young pop in child bearing yrs • Asia and LA 33% of pop under 15 • Africa 40% of pop under 15 • Ex: In 2002 both UK and S. Korea had fertility rate of 1.6. But projections for 2025, older UK will decline by 2 mill and youthful SK will add 2 mill.

2.3 Demographic Transition Model 

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4 stage model shows similar process of pop change in all societies over time Every country is at some stage The model is irreversible…you do not go back

STAGE ONE: LOW GROWTH 

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Very high CBR and CDR cancel each other out Almost no long term natural increase Most of human history spent in stage one No country is here today

STAGE TWO: HIGH GROWTH 

Rapidly declining CDR but CBR remains high and = very high NIR • @ 1750 – late 1800s nations in Ind Rev (Eur and N. America) moved into stage 2. Improved agric and health care dropped CDR. • First time in world history to have significant growth • LDCs entered stage 2 @1950 when MDCs diffuse improved medical tech (vaccines) to LDCs. • Most of Africa in stage 2 today

STAGE THREE: MODERATE GROWTH 

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CBR rapidly declines and CDR continues to decline slowly. NIR begins to moderate CBR drops b/c of social customs – access to birth control, infant mortality rate drops, women in work force, kids become econ drain Eur and NA enter - first half of 20th C Asia and parts of LA moved here in recent yrs

STAGE FOUR: LOW GROWTH 

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Very low CBR and CDR produce almost no long-term natural increase and possibly a decrease Zero pop growth: CBR and CDR = • TFR of 2.1 produces zero growth

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Most Euro countries in stage 4 today Countries w/ negative NIR…Russia and Japan (shrinking)

Possible Stage Five? 

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In future if higher CDR than CBR you’ll have irreversible pop decline. If a country stays in stage 5 without migration it will eventually cease to exist

Generalities of the Model 

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No one in stage 1; only a few have reached stage 4 Model has 2 big breaks w/ the past • First break: sudden drop in death rate (stage 2) from technology and has taken place everywhere • Second break: sudden drop in birth rate (stage 3) comes from changing social customs and has not taken place everywhere

2.4 Population Structure and Composition 

Population pyramids…show age and gender groups. How do MDC’s and LDC’s differ? • 1.) Sex Ratio: # of males per 100 females. In general slightly more males born, but women outlive men  

Eur and NA 95 males: 100 females World wide 102 males: 100 females

Pop Structure and Composition – cont’d. 

2.) Age Distribution • Dependency Ratio: # of people too old or young to work, compared to # of people in productive yrs. 

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% of pop under 15 = % over 65 divided by % in between 15-65 multiplied by 100 Tells you how many dependents for every 100 workers Stage 2 countries: ratio is 1:1 (1 worker for every dependent) Dependents are young Stage 4 countries ratio is 2:1 (2 workers for every dependent) Dependents are young and old

Age Distribution – cont’d • Graying of the pop in MDCs – more than ¼ of all govn’t expenditures in US, Canada, Japan, and W. Eur goes to Social Security, health care, and other programs for the elderly • Baby Boomer Cohort in US (born 19461964)…what does this mean for you? • Generation X = 1965-1980

Population Structure and Composition – cont’d 

Race and Ethnicity: Hispanics now largest minority in US (recently passed African Americans) • 11% of US pop is foreign born  

50% of that from LA 50% of that from Mexico

What do you see? Why?

Overpopulation and Sustainability 

Should we worry @ overpopulation? • Thomas Malthus – 1798 wrote “Essay on the Principle of Pop” and argued 

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people need food to survive and have natural desire to reproduce Food prod increases arithmetically and pop increases geometrically/exponentially Predicted pop growth would eventually outpace people’s ability to produce food leading to starvation and famine

Malthus and his theory

Neo Malthusians 

Argue that 2 characteristics of recent pop growth make Malthus’ argument even more frightening • Esp high growth in LDCs • Pop growth outpacing econ dev in many LDCs (i.e. income rises 20% but pop rises 30%, so some LDCs worse off than they were 30 yrs ago) • Paul Erlich – most prominent neo-Malthusian. Wrote “Population Bomb” in 1968 – warned of mass starvation due to overpopulation http://overpopulationisamyth.com/ov erpopulation-the-making-of-a-myth

Critics of Malthus 

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Malthus did not account for ability of people to increase food prod dramatically w/ new technology (go to video 3) Malthus did not foresee family planning and birth control and drop of CBR/NIR Malthus did not recognize that famine is usually NOT related to a lack of food but to unequal dist of food – Marxist approach http://overpopulationisamyth.com/ov erpopulation-the-making-of-a-myth

Population and Sustainability 

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Carrying Capacity: # of people a given area can maintain…surpassed in densely populated places Overpopulation implies a breach of an area’s carrying capacity. Also involves • • • • •

Over consumption of resources Inefficient allocation of goods Unsustainable land use MDC’s blame LDC’s – have too many babies LDCs blame MDCs – consume disproportionate share of world’s resources

Control of Population 

Pro-Natalist Policies – government policies to promote reproduction and bigger families • Ex. Tax breaks

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Anti-Natalist – government and social policies that discourage reproduction to reduce pop growth rates • Tax breaks for sterilization • One-child policies – may lead to gender imbalance

Control of Population 

Improve local and state economies • Better school, more eco opportunities

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Reduce CBR through the use of contraception • Family planning programs in LDCs • Why is this sometimes difficult?

Epidemiological Transition Model  

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At times high CDR have lowered NIR Stage 1: Pestilence and Famine: i.e. infectious diseases…ex: Black Plague 1350s kills ½ Eur pop Stage 2: Receding Pandemics: improved sanitation, nutrition, medicine of Ind Rev decreases spread of infect diseases

Epidemiological Transition Model Cont’d 

Stage 3: Degenerative and Human Created Diseases • Fewer deaths from infectious diseases • Increase in chronic disease associated w/ aging (heart disease and cancer)

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Stage 4: Delayed Degenerative Diseases – degenerative diseases linger but life exp is extended trough medical advances (bypass, radiation, chemo, etc.)

Epidemiological Transition Model Cont’d 

Possible Stage 5 – Reemergence of Infectious and Parasitic Diseases • Evolution of new strains of bacteria (TB, polio, malaria) • Poverty – people cannot afford drug treatment (TB) • Improved travel diffuses diseases faster (AIDS)