Current World Population
http://www.worldometers.info/population/
07/25/11 at 02:16 is 311,838,466
World: 6,979,491,043
One birth every................................................ 7 seconds
One death every............................................. 13 seconds
(we added a whole second since last year)!
One international migrant (net) every............ 45 seconds
(It was 29 last year)
Net gain of one person every......................... 12 seconds
History of Human Population Growth
Years Elapsed
Year
Human Population
3,000,000
10,000 B.C. (Agricultural Revolution)
5-10 Million
10,000
1 A.D.
170 Million
1,800
1800
(Industrial Revolution)
1 Billion
130
1930
2 Billion
30
1960
3 Billion
15
1975
4 Billion
12
1987
5 Billion
12
1999
6 Billion
10
2009
6.8 Billion
Terms to Know:
• Death rate: number of deaths per year per every 1000
people
• Birthrate: # of births per year for every 1000 people
• Natural increase = birthrate – death rate
• Zero population: birthrate and death rate are =
• Doubling time: number of years it takes to double in
size
• Negative Growth Rate: death rate exceed birthrates
Rates of Natural Increase
The world’s population is growing because:
•Better medical care / medicine
•Improved sanitation
•Lower infant mortality
•Longer life expectancy
•Birth rates not declining as fast as death rates.
•More abundant food.
•Better living conditions
Birth rates have not increased. Around the world women are
actually having less children than in the past.
Challenges to Rapid Growth
• Difficulty producing enough food
• Use resources too quickly
• Too many children – not contributing to farming
or paying taxes.
What problems can be caused by population increase?
• We will need more of everyday things: Food, land to grow food, clean
water, shelter, schools, hospitals, roads, energy
•Poor will probably not be able to change circumstances because more
people will be sharing the same amount of resources
•Governments will have difficulty keeping up with demands of the
people.
Negative Population Growth
• Must import workers from other countries.
• Immigrant populations don’t always get
along with native population.
Growth in More Developed and
Less
Developed
Countries
10
9
8
7
6
5
4
3
2
Less Developed Countries
1
0
1950
Billions
More Developed Countries
1990
2030
Present Rate of Growth
80 Million a Year
World Adds as many people as:
• 1 New York City every month
• 1 Germany every year
• 1 Europe every decade
Population J-Curve
Estimated
Population:
9 billion by
2025
12 Billion by
2050
Annual World Population Growth Rate
1.4%
At current growth rate
by 2050 world population will be:
12 Billion
World’s most populated countries
Know top 5
Where do people live?
• 61% live in Asia.
• Most people want to live on
– Fertile soil
– Near available water
– In a mild climate
World Population Density Map
Population density is people per square mile / kilometer – total
population divided by total land area.
What is the most important factor influencing
population distribution?
Geography!
There are some areas that are not suitable or
comfortable to live – too hot, too cold, too high,
swampy, dry, rocky, etc.
Population distribution is where people actually live.
All the world’s people live on about 1/3 of the world’s
land
Think about it – very few people live in Alaska
Egypt as a Case Study
• Arithmetic = 181 per sq. mile
• Physiological = 5,807 per sq mile
• Why the disparity?
Migration?
• Natural increase does not account for migration –
movement of people from place to place
• Common migrations:
–
–
–
–
Rural to urban
Why do you think this occurs
Country to country
Emigrants in their homelands; immigrants to new
county
– Why do you think this occurs?
Demographic Transition Model
Problems with the
Demographic Transition Model
• based on European experience, assumes all
countries will progress to complete
industrialization
• many countries “stuck” in stage 2 or stage 3
• reflects logic of continuous growth, an
impossibility
When geographers want to examine
the structure of a population and the
potential for growth in that population,
they turn to a basic tool in demography:
the population pyramid.
Just as a builder uses a blueprint for
depicting
the structure of a house, a geographer
uses
a population pyramid as a blueprint
for interpreting the
dynamics of a population
Population Pyramids:
 graphically display a population's age
and gender
 are bar graphs;
 show numbers or proportions of males
and females in each age group
 show gains of cohort members due to
immigration and birth,
 show loss of cohort members due to
emigration and death;
 reflect population growth or decline
Rapidly Growing Population –
usually developing & poor
Slow Population Growth – usually
developed - stable
Negative Population Growth – will
need to import workers. Notice
the big change between 25-29
and 20-25 and also 20-25 and
15-19
Population Structures by Age and Sex, 2005
Millions
Less Developed
Regions
More Developed
Regions
Age
Male
300 200 100
Female
0
100 200 300
80+
75-79
70-74
65-69
60-64
55-59
50-54
45-49
40-44
35-39
30-34
25-29
20-24
17-19
10-16
5-9
0-4
Male
300
Female
100
100
300
That long arm of post-adolescent males should be a dead
giveaway for a military town, in this case Onslow County, NC,
home of Marine Corps Base Camp Lejuene.
The tourist town has little opportunity for young adults and they
clear out as shown here in Narrangasett, RI.
Seniors rule in Sarasota, Fl, but not the ones in high school. The high
concentration of senior citizens puts Sarasota County Transit at among
the highest demand response trips per fixed route trip in Florida.
The overwhelming number of co-eds should instantly reveal the college
town, this one the home of the Gators, Gainesville, FL.
Computer engineers – small families – working women and men.
Brandt Line – haves and have nots.