Transcript 1-2 Population Growth

Warm-Up
A scientist places one
bacteria in a Petri
dish at 9:00 am. The
bacteria can
reproduce at a rate
that doubles its
population every
minute. The scientist
observes that the
Petri dish is
completely full at
10:00 am.
1.
2.
3.
What do you think will happen after 10 am?
In what ways is this example similar to human
population growth?
In what ways is this example different from
human population growth?
The Human Population
 Exponential growth – a quantity increases
by a fixed percentage in a given time
 The world’s population is increasing at 1.15%
every year
Human Population Growth Over Time
Industrial
Revolution
Year
The Rule of 70
 The “Rule of 70” is an easy way to
estimate how long it will take a
population to double, if you know the
growth rate
The Rule of 70
 Ex: If a population’s growth rate is 7% a
year, how long will it take to double in
size?
70/7% = 10 years
The Rule of 70
 If a country’s population is increasing at
about 2% every year, how long will it
take to double in size?
70/2% = 35 years
The Rule of 70
 Ex: If a population’s growth rate is 5% a
year, how long will it take to double in
size?
70/5% = 14 years
The Rule of 70
 The world’s population is increasing at
about 1.15% every year, how long will it
take to double in size?
70/1.15% = 61 years
Human Population Density
Human Population Density
Population Map
Wealth Map
Think About It
 343,000
Amount by which the population of all
European Union countries combined
grew in the year 2000.
 343,000
Amount by which India's population grew
in the first week of 2001.
If the world were a village of
100 people, there would be:
 60 Asians
 14 Africans
 12 Europeans
 8 Central/South Americans & Caribbean
 5 North Americans
 1 Oceania
If the world were a village of
100 people, there would be:
 80 living in substandard housing
 50 suffering from malnutrition
 33 lacking access to safe drinking water
 24 lacking electricity
WORLD POP.
Developed
Countries
Developing
Countries
U.S., Canada,
Australia, NZ,
Japan, Europe
Africa, Asia, Latin
American, South
America
• > $10,750 per capita GNI
• < $10,750 per capita GNI
• 19% of world pop.
• 81% of world pop.
• 85% of world’s wealth
• 15% of world’s wealth
• Use 88% of resources
• Use 12% of resources
What Do You Think?
 Are developed countries, like the U.S.,
obligated to help developing countries
develop?


Should we be sending our money to other
countries to help provide them with food,
clean drinking water, etc.?
Are we obligated to offer financial
assistance to developing countries, like
Haiti, who have suffered a natural
disaster?
A Changing Population
 Based on the differences between
developed and developing countries,
which do you expect to be increasing in
size faster? Developed or developing?
Population Questions
 Should we be
concerned with the
increasing world
population size?
 What should be done to
slow the rate of growth?