5. Implications of exponential (or
geometric) growth
• Large amount of extra resources needed to
feed, house and clothe
• Argument that this is easier for LEDCs
(less economically developed countries)
than MEDCs (more economically
developed countries)
6. Key values
• Crude birth rate
• Crude death rate
• Fertility
• Natural increase rate
• Doubling time
11. Doubling time
• The length of time required for a population
to double its size
12. Transition
• As countries develop from LEDC to MEDC,
their demographics change
13. Population pyramids or Age/sex pyramids
What interpretations can be made here?
High tax on young to
High infant mortality Population maintained
support older
by immigration
generation
14.
15. Expanding Expanding Stationary Contracting
Population
declines
20. Carrying capacity
The maximum number of a species that can be sustainable supported
by a given environment (see Irish population crash)
Malthusian theory (1978)
• food supply the main limit to population growth – environmental limits
• food supply will even decrease due to over-cultivation and erosion
known as ‘the law of diminishing returns’
• The Club of Rome, an NGO, is neo-Malthusian
Boserup’s theory (1965)
• increased population would stimulate increased food production
through technology summarized as ‘necessity is the mother of
invention’
• desertification are evidences where overpopulation has not led to
technological innovation
21. Problems in predicting
human population growth
When one
resource runs out
humans change to
another
Human
ingenuity
Resources can be Technology
imported in changes the
resources
(mining in available and
space!?) amount required
24. Ecological footprint
The ecological footprint of a population is the area of
land that would be required to provide all the
population’s resources and assimilate all its wastes
For individuals:
25. Calculating the ecological footprint
of a population
Ecological footprint
= (equation 1 + equation 2) x total population
27. Missing factors
• Land or water required for aquatic and
atmospheric resources
• Land needed to assimilate wastes other
than CO2
• Land used to produce imported materials
• Replacement of arable land through
urbanization
29. MEDC vs LEDC
• Highly
industrialized
• Low forest growth
(colder climate) • High forest growth
• High meat diet (temperate climate)
• High grain diet
• Similar to US but with a
low population
30. Population policies
Lowering population growth through:
1. Economic development
• MDG (millennium development goals)
• Economists believe increased prosperity decreases
the birth rate
2. Government policies
• One child policy of China
• Taxes and other incentives/disincentives
3. Education
• Education about birth control
• Education of women leading to independence is seen
by some as the most effective way to reduce
population
