POPULATION ISSUES
Define demographics
Population has grown from 1 billion in 1800
to over 6 billion today.
80% of the world’s population lives in pings
90% of the world’s population lives above the equator.
People are living longer in virtually all
countries. Why?
Medical revolution
Arithmetic growth: 2,4,6,8,10,12,
etc….
Exponential growth: 2,4,8,16,32,64,128,
etc….
Population grows exponentially.
Doubling
time
The number of years it takes for a population to
double.
At a rate of 3% growth per year, a
population will double in 25 years.
For now and the forseable future, most live in Africa and Asia.
Technology has allowed people to adapt to natural constraints
in growth.
First Agricultural
Revolution
Neolithic Revolution
Second Agricultural
Revolution
Industrial Revolution
Third Agricultural Revolution
Green Revolution
When does a country become
overpopulated?
When it exceeds its carrying
capacity (when it can’t feed its
people.)
Terminology:
Rate of natural increase
Crude birth rate
Infant mortality rate
Affected by economic development
(healthcare, employment, nutrition,
education.)
Crude death rate
Fertility rate
The better women are educated, the lower the RNI.
Gender empowerment
Cultural
traditions:
Public
policy:
Women are expected to stay
home and raise children.
China, India,
France
How is the One Baby Policy
affecting China’s future?
Population Sustainability
Carrying
capacity:
The number of individuals can support.
Find the lowest common denominator.
PEDS make up around 20% of
the world’s population, yet use
75% of the world’s resources.
The percentage of the world’s
surface that is fit or habitation
is called the “ecumene.”
Popualaion density:
Arithmetic
density
The heaviest
populated
regions.
Is population
density a good
gauge for
development?
Physiological density
Agricultural (arable)
density
Demographic Transition
Model
Stage I: high birth rate,
high death rate, little
growth.
This describes most of
human history.
Stage II: high birth rate, low death
rate.
Peds and pings?
Industrial and medical
revolution.
Stage III: low birth rate, low
death rate.
A generally balanced
population.
Stage IV: low birth rate,
low death rate.
Population is not being replaced
at a fast enough pace.
Thomas Malthus
Writing in the early 1800’s, Malthus
predicted dire consequences as the
population began to boom. He stated
the population would soon exceed the
food supply.
What did he not account for?
Neo-Malthusians: Current
People today who are once again
predicting the population would
outstrip the food supply.
Population pyramids
Displays the gender and age of age groups.
Which are peds,
which are
pings?
Give an example
of a country
(region) that
would match
each pyramid.
You can predict trends for
the future.