Note: The models of growth will be
discussed later. Use this PPT to learn
about Population Pyramids and
stages of growth.
• Model: a simplified
structuring of reality
•
•
•
•
•
•
Malthusian
Boserup
UN Statistics
U.S. Census Bureau
Age/Sex Pyramids
DTM
• Only as good as the data inputted
• Boundary conditions
• Easier to understand
• Useful for predictions
http://en.wikipedia.org/wiki/File:World-Population-1800-2100.png
3.1.4 Models…
3.1.1 Malthusian Theory
• Thomas Malthus An Essay on the Principle
of Population (1798)
• Food is the limiting factor
• Exponential population growth vs.
http://www.fordham.edu/halsall/mod/lect/malthus.gif
•
•
arithmetic food growth
Refers to environmental limits
The Club of Rome (NGO) is neo-Malthusian
• Limitations of Malthusian theory
• Ignores the poor (most affected; likely
•
•
distribution problems)
Agrarian technology – football pitch
produces for 1000 people
Globalization – import/export
3.1.1 Boserup’s Theory
• Esther Boserup, Danish economist
(1965)
• Increasing population → increasing
food production (technology)
• “necessity is the mother of invention”
• Refers to cultural & tech issues
• Limitations of Boserup’s theory
• Like Malthus, infers “closed” system
(immigration/emigration)
• Globalization – import/export
• Overpopulation can lead to
unsustainable farming
http://upload.wikimedia.org/wikipedia/en/7/74/Graph_boserup.JPG
3.1.3 Age/Sex Pyramids
• Shows living
individuals in different,
5-year cohorts
(groups) in a country
for a given year
• Split into male/female
• Population on x-axis,
age groups on y-axis
• Shape indicates stage
of development in a
country at a particular
time.
CHINA
AUSTRALIA
3.1.3 Age/Sex Pyramids(cont’d)
Retrieved on 03-11-2011 from: http://geographyfieldwork.com/Pop4.gif
3.1.3 Demographic Transition
Model
http://www.geogonline.org.uk/as_g2popdtm.htm
Indicators in Development
http://en.wikipedia.org/wiki/File:DTM_Pyramids.svg
3.1.4 Predictions
• BBC: 7 000 000 000
People
Retrieved 12-12-2012 from:
http://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Wor
ld_population_(UN).svg/300px-World_population_(UN).svg.png
3.1.4 Predictions