APES Chapter 6 - The Human Population and Urbanization

6-1 How many people can the earth support? Can the earth keep growing?

World Population

8 billion

• 70 million people added each year

Demographers

population experts

(pop trend)The current growth rate is…

Declining (currently 0.88%)

Growth rate has slowed although the population continues to grow

• Due to limited resources

• Env impacts/footprint (I=PAT)

• Econ growth Vs. Poverty

• Cultural and religious influences

(Pop trend) Human population grows unevenly true or false?

True - most of people added to the population are in LDC’s

(pop trend) Describe the movement of people?

From rural to areas to cities. Great majority of urban dwellers live in LDC’s

How does human growth impact natural capital?

Growth of human pop =.growth eco footprint = bigger impact on natural capital.

Examples of natural capital degredation:

Reducing biodiversity, increasing NPP, eliminating natural predators, disrupting chem cycles…

How did the human population increase so rapidly?

The human population is modeled by the J-Curve (exponential growth for the past 200 years)

1. Human intelligence and adaptation - enabled expansion to diverse habitats and new climate zones.

2. Agriculture - feeds more people per unit area

3. Medical tech and sanitation - control infectious diseases

What has driven pop growth over past 100 years:

Decline in Deat Rate and not an increase in Birth Rate

Cultural carrying capacity

Max number of people who can live in reasonable freedom and comfort indefinitely, without decreasing the ability of the earth to sustain future generations

6-2 What factors influence the size of the human pop? (5)

• Births, Deaths, Migration

• Population change equation(increases with B+I and decreases with D+E)

What is the key factor that determines population size?

The average # of children born to the women in a population (fertility rate)

Crude Birth and Death Rate

# of live births or deaths per 1000 people per year

Annual global Growth Rate Calculation

= 0.84%

(crude births - crude deaths)/10

Rule of 70

70/%growth rate = doubling time in years

*if negative (time it will half)

Fertility Rate:

A measure of how many children are born in a pop over a set time.

2types: replacement level ft, TFR

Replacement level fertility

# of children a couple must bear to replace themselves (aprox 2.1 to 2.4)

Total fertility rate (TFR)

Average # of children a women has in her reproductive years.

In 1955 this was 5 in 2011 it significantly dropped to 2.5

Factors Affecting Birth rates and Fertility rates. WHY do people have or dont have kids (9):

1. Child Labor (important in LDC’s)

2. Cost of raising and educating children (more expensive in developed countries)

3. Availability or lack of pensions (reduce kids due to financial security later in life)

4. Infant Mortality Rate (directly proportional to TFR more prevalent in poorer countries)

5. Urbanization (better access to family planning services in cities)

6. Education and Employment of Women (TFR drops with increasing education and employment opportunities

7. The average age of marriage (fewer children when marriage age >= 25)

8. Avalibity of legal abortions and birth control

9. Culture, religious values, and traditions

Factors effecting death rates:

1. life expectancy - indicator of overall health of a pop, avg # of years a person is expected to live

2. Infant mortality rates - the # of babies out of every 1000 born who die before 1st birthday

   • High: undernutrition, malnutrition, disease

   • More than 4mill infants each year die from preventable diseases

Survivorship Curve

Shows the probability that that individuals will survive to a certain age.

Type 1 (Survivorship Curve)

Most individuals survive to maturity and beyond (often large animals k-stradegists)ex. humans

Type 2(Survivorship Curve)

Constant death rate (linear decrease) often prey org

Type 3 (Survivorship Curve)

Very high early life mortality followed by a steadying rate of survival (often animal r-strategists, many plants)

Survivorship is an indicator of population health.

If type 2 or 3 that indicates poor living conditions

Which countries’ growth is faster than all other developed countries?

US (key factor immigration)

For immigration arguments: tax revenue, workers needed as boomers retire

Against immigration arguments: population stabilizes, lower eco footprint

6-3 How does a population’s age structure affect its growth and decline?

The numbers of males, females, young, middle, and older determine the growth or decline of pop (age structure)

(view worksheet)

Reproductive age effects:

ages 15-44

a country with majority of younger people result in rapid pop growth

most future human pop growth will occur in LDC’s

Populations made of older people can decline rapidly:

future greying of world

people ages 65+ = pop decline (ex. japan, russia germany)

(ex. japans bleak econ future as most of the pop is older)

Population can decline due to rising death rate?

Ex. AIDS, removes a long of young adults.

Resulted in a sharp drop in life expectancy, loss of workers = loss of taxpayers…

Problems with rapid population decline:

1. Can threaten economic growth

2. labor shortages

3. less government revenues = fewer workers

4. less entrepreneurship + new business formation

5. less likelihood for new tech

6. Increasing public deficits to fund higher pension and health care costs

7. pensions may be cut and retirement age increased.

6.4 How can we slow human pop growth? 3 most effective ways include…

By:

1. reducing poverty(fertility and pop growth high in LDC)

2. elevating the status of women, and

3. encouraging family planning + reproductive health care.

Demographic Transition Graph (think of wokt graph with stages):

As countries becomes industrilized and economically developed their population tends to grow more slowly (4 stages)

• view graph on phone Oct 18

Stage 1

Pre-Industrial

Pop grows very slowly b/c of the high birth rate (to compensate for high infant mortality) and a high death rate.

Stage 2

Transitional

Pop grows rapidly b/c BR high and DR drops because of improved food production and health.

Stage 3

Industrial

Pop growth slows as both BR + DR drop b/c of improved food production health, and education.

Stage 4

Postindustrial

Pop growth levels off and then declines as BR = and then fall below DR

• can also LDC achieve this stage

• Yes b/c of tech

• No due to less econ support from LDC’s

Family Planning

provides educational and clinical services that help couples choose how many children to have and when to have them