http://www.pbs.org/wgbh/nova/worldbalance//

http://opr.princeton.edu/popclock/

http://www.peterrussell.com/Odds/WorldClock.php

Chapter 5

• World Population Trends

• Calculations

• Developed vs. Developing Countries

• Age Structure Diagrams

• Demographic Transition

Chapter 6

• Fertility Rates

• World Bank

• 1994 UN Conference in

Cairo- Program of

Action

(In 2000) 11.5 billion & 2065(?)

(In 2008) 10 billion & 2200

OLD NEW

2046 2200

2033 2047

2020 2024

2009 2012

1999 1999

1987 1987

1975 1975

1960 1960

1930 1930

1830 1830

Disparities

• Developed countries– 15% of the world’s population– Control 80% of the world’s wealth

• Low-income developing countries– 37% of the world’s population– Control 3.0% of the world’s gross national

income• Difference in per capita income: 63 to 1!

Different Populations, Different Problems

• IPAT Formula: calculates human pressure on the environment (I = P x A x T)– I = environmental impact– P = population– A = affluence and consumptive patterns– T = level of technology in the society

Or should it be I = PxAxT/S

(S = Stewardly Concern/Practice)

Different Populations, Different Problems

• Environmental impact of developing countries due to “P.”

• Environmental impact of developed countries due to “A” and “T.”– Both have some measure of “I” for different

reasons.– Average American places at least 20 times

the demand on Earth’s resources compared to a person in Bangladesh.

(b) crude birth rate= number birth per 1000 individuals(d) crude death rate= number death per 1000 individuals(r) growth rate = natural increase in population expressed as percent

per years (If this number is negative, the population is shrinking.) equation:

r = b – d

But other factors affect population growth in a certain area…

Rates cont’increase population decrease population births deathsimmigration emigration (exit)

r = (birth - death)+ (immigration-emigration)immigration = migration of individuals into a population from another area or countryemigration = migration of individuals from a population bound for another country

r = (b - d)+ (i - e)

B D I E r=( 10/1000) – (5/1000) + (1/1000) – (10/1000) r=(0.01-0.005) + (0.001 – 0.01)r = 0.005 – 0.009 = -0.004 or –0.4% per year

example: population of 10,000 has 100 births (10 per 1000)50 deaths (5 per 1000)10 immigration (1 per 1000)100 emigration (10 per 1000)

You try.

Growing Cities

Doubling time = 70 / % growth rate

  Use this equation to answer this question:

How long will it take for a population to reach a certain size?

If the growth rate is 1% and the population size is 10,000, how many years will it take to get to a population of 40,000?

Population doubling:

In 140 years, the population will be 40,000 people.

(70 years)(2) =140 years 

2 D.T. 40,000

1 D.T. 20,000

In 70 years the population will be 20,000

70/rate =70/1% =70 years to double

In the year 2000 there are 100,000 people living in Paradise. Every year, 10 people emigrate from paradise and 10,000 people immigrate to paradise. 100 people are born each year and 100 people die each year.

a) Calculate the doubling time for the population of Paradise.

b) How many years will it take for Paradise to have 400,000 people?

c) If you were the President of Paradise what would be your policy for population control. (major problem in Paradise)

 

And Pg. 141 Thinking Environmentally #3

The transition from a primitive or developing society to a “modern” or developed society  Phase 1 = deaths and births are high

(epidemiological) Phase 2 = death rate begins to decrease

(fertility) Phase 3 = birth rate drops and death rate flattens out

Phase 4 = modern stability

There is little population growth in phase 1 but in phase 4 people live longer and have fewer children and the population grows. 

Bottom Line= as countries develop, first their death rate drops and then their birth rate drops

Reasons for the phases:

Phase II: medical care

nutrition (births still high)

technology

Phase III: birth control

education (of women)

lower mortality rate of infants

less child labor

Developed Countries Canada, U.S., Australia, Denmark

Developing Countries Brazil, China, Kenya

1/5 of the world’s population lives in absolute poverty (which means they are: illiterate, lack clean H2O and don’t have enough food to survive)

80% of world’s population lives in developing countries and this number is growing . . .

• Total fertility = avg. # of children born per woman

• Fertility of 2.0 = replacement level (theoretical)– About 2.1 in reality

– Under 2.0 = shrinking population– Over 2.0 = growing pop.

Population Data for Selected Countries (Table 5-2)

Country Total Fertility Rate

Doubling Times (Years)

World 2.7 58

Developing Countries

2.9 47

Developed Countries

1.6 700

• Special agency of the United Nations• Receives $$ from developed co. and loans

$$ to developing co. – Sometimes this backfires by increasing debt

• Oversees all types of issues, not just environmental issues– Ex. electricity, roads, new modern technology

Reached consensus on:• Empowerment of women• Improving reproductive health• Increasing basic education• Enhancing family income• No changes to the World Bank