GEOS1100 Lecture Notes - Lecture 2: Risk Aversion, Population Ageing, Demographic Transition
29 May 2018
School
Department
Course
Professor
WEEK 2
LECTURE 1
Why did global population explode in the 20th century?
• People stopped dying, babies stopped dying
Why is the rate of global population growth decreasing?
• Less people are having babies
Why is growth higher in LDC than in MDC?
What are the consequences of this rapid growth and its subsequent slowdown?
What is the global world population? 27.6 billion
What is Australia’s population? 24 million → hitting 25 in 2018
Trends in global population
• 100 A.D - 300 million
• 1600 - 500 million
• 1800/1850 > 1 billion
• 1950 - 1.6 billion
• 1950 - 2.5 billion
• 1980 - 4.4 billion
• 1989 - 52.19 billion
• October 1999 - 6 billion
What if the world doubled every 40 years?
World Scale
Australia
Pessimists
Population growth is the
single most significant
threat to the natural
environment, indeed to
the future of life on earth -
professor Paul Enrich
Australia should reduce its population to its
ecological carrying capacity of around 6-10 million
Optimists
Population is a course of
ingenuity that will resolve
all problems. We have the
technology to cater for an
ever-growing population,
forever
Australia should aim for a population of around
50-60 million
Was Malthus right?
FOR Malthus
• Population ‘bomb’
• Resource wars (e.g Rwanda)
• “Carrying capacity” (e.g. Easter Island)
AGAINST Malthus
• Population levelling off
• Dramatic increase in food production (e.g. Mauritius)
But living longer and fewer people in extreme poverty and growth in literacy material well
being
At what cost?
Impact = Population (I=P)
The Significance of Population
Population as the principal culprit in environmental degradation..?
The Environmental Impact Equation:
I = f (P, A, T)
Where:
I= Environmental impact
A= Affluence
P= Population
T= Technology
Sometimes written as I= f (P, C, T) where c = consumption
LECTURE 2
Fertility
The Basic Demographic Equation
P^ t+n = p^t + (B-D)
Where p^t is population at time t plus n years
P^t ix population at time t
B is births occurring between t and t+n
D is deaths occurring between t and t+n
And for individual countries or regions
I represent gains from immigration
O represents losses through emigration
Why might numbers of death may be declining --->overall mortality declining in populations
Deaths increasing over time? -→ ageing population
In more developed countries we are entering a period of natural decline in rates of deaths
Why still overpopulated? Migration
Births have stabilised in less developed countries
Births and deaths high? No natural increase, oxalises till to mortality events - epidemics
Measuring fertility
CBR : Crude Birth Rate - number of births in a year per thousand population
Why is age important? - old people do not reproduce
Doesn’t account for age and doesn’t account for female
REFINES RATE BY
TFR : the total fertility rate - average number of children a women will bear during her
lifetime
NRR: The Net reproduction rate : the number of daughters a woman will bear who in turn
survive to complete their own child bearing
Replacement Fertility is the level of fertility needed for a woman to just replace herself in the
next generation = NRR of 1.0 (TFR= approx. 2.1)
• Infant mortality rate
• More male babies born than female babies
Document Summary
Why did global population explode in the 20th century: people stopped dying, babies stopped dying. Why is the rate of global population growth decreasing: less people are having babies. Trends in global population: 100 a. d - 300 million, 1600 - 500 million, 1800/1850 > 1 billion, 1950 - 1. 6 billion, 1950 - 2. 5 billion, 1980 - 4. 4 billion, 1989 - 52. 19 billion, october 1999 - 6 billion. Australia should reduce its population to its ecological carrying capacity of around 6-10 million. Australia should aim for a population of around. Population growth is the single most significant threat to the natural environment, indeed to the future of life on earth - professor paul enrich. Population is a course of ingenuity that will resolve all problems. We have the technology to cater for an ever-growing population, forever. For malthus: population bomb", resource wars (e. g rwanda) Against malthus: population levelling off, dramatic increase in food production (e. g. mauritius)
