Slides in this set
How has the rate of population
changed over time?
·It is clear from many graphs and statistics that the population of the world has increased rapidly
from the year 0 BC
Different estimates and reasons for the increase were given, but many of the increases were a
result of developments in technology:
·Development of crop growing rather than simple gathering
·The invention of metal tools
·Advances in plant breeding
·Inventions in machinery which can be used in agriculture
·Advances in medicine and hygiene
·Developments in the preservation and storage of food
The biggest and most rapid sustained growth in the population occurred between 1700 and
present. A number of factors came together to support this rate of growth:
·The industrial revolution
·The agricultural revolution (breeding of plants / animals, mechanisation of agriculture, scientific
use of fertilisers, improved transport & marketing etc)
·Better understanding of hygiene and it's importance in reducing spread of disease
·Improved transport and navigation, which opened up many parts of the world to trade and
allowed the spread of the technologies…read more
What causes population
Here are some of the factors that help of explain the changes in population
·Death rates fluctuated up until about 1740. Death rates rose when epidemics of illness struck. The birth rate
will stay high to compensate for the high death rate.
·Between 1770 and 1870 the infant mortality rate fell, mainly as a result of improved nutrition.
·From 1780 onwards, improvements in agriculture helped to provide a more reliable food supply for the
·From 1800 the industrial revolution led to a move to towns. Factory owners tried to ensure there was enough
food to keep the work force efficient.
·As the towns grew, the death rate increased due to insanitary conditions in the towns
·Public health acts in the mid and late 19th century led to improved water supply and sewage disposal systems
in the towns.
·Through most of the 19th century, demand for labour in the factories and low wages for the workers meant
that it was an economic advantage to have a large family to add to household income.
·Compulsory education and factory reforms after 1870 made employment of children much more difficult.
·In the 1870s leaflets were published promoting birth control.
·In 1906 the government took positive action to improve the health of mothers, infants and school children.
·From 1870 onwards, scientific developments steadily improved medical and surgical practice.
·The birth rate fell during the 2 world wars and the depression of the 1930's.
·There was a marked baby boom after WW2.
·The use of oral contraceptives and other contraceptives became widespread after the 1960s.
·The abortion act in 1967 legalised abortion in some circumstances.…read more
The Demographic Transition
The demographic transition model is based on experience of changes that took place in Britain, and some other industrialised
countries, during the 19th and 20th centuries. In several of these countries population in terms of birth rates, death rates and
total population was seen to have gone through a series of stages in logical order.
The demographic transition model has strengths and weaknesses. It is particularly strong as a descriptive model but less strong
as a predictive model.
·Dynamic, showing change through time.
·Describes what has happened in the UK.
·Many other countries in Europe and North America went through similar stages as they industrialised.
·Some NICs such as Singapore and South Korea also seemed to go through similar stages, but faster than countries like Britain
·The model helps to explain what has happened and why it has happened in that particular sequence.
·It is based on the experience of industrialising countries and is not relevant to non-industrialising countries.
·The model assumed that stage 2 followed from industrialisation. In many countries this has not been the case. The factors that
cause the death rate to start falling (better medical care / sanitation etc) were imported from colonising countries and so arrived
far more quickly than in Europe.
·The model assumed that stage 3 followed several decades after stage 2 and the death rate fell as a consequence of changes
brought about by changes in the birth rate. This has often not been the case. In some countries the onset of stage 3 was held
back by the population's attitudes to family size, birth control, status, religion etc. In other cases the fall could be speeded up by
government intervention (such as Chinas one child policy.)
·The original model has been adapted to include a 5th stage. This stage is now clearly seen in some countries where the death
rate exceeds the birth rate.
·Countries of southern Africa, where the death rate has risen dramatically because of HIV/AIDS, appear to have slipped back
into stage 1. The model does not help predict the future for these countries.…read more
The Demographic Transition
STAGE 1 STAGE 2 STAGE 3 STAGE 4 STAGE 5
Both birth rates and Birth rates remain high Birth rates fall rapidly to Both birth rates and Two groups of countries
death rates fluctuate at but death rates fall 16 in 1000 while death death rates remain low appear to have entered
high levels giving small rapidly to about 20 in rates fall to 12 in 1000 and fluctuates slightly to stage 5. These are some
population growth. Birth 1000 people giving rapid slowly increasing give a steady countries of Eastern and
rates are high because: population growth. Fall population. Fall in birth population. Central Europe where
in death rate because: rates due to: the birth rate has fallen
·No birth control /family ·Family planning / below replacement level
planning. ·Improved medical care contraceptives and some countries of
·High infant mortality so (vaccinations, doctors, ·Lower infant Southern Africa where
parents produce more, hospitals, drugs) mortality=less pressure HIV/Aids has caused a
hoping more will survive. ·Improved sanitation to have many children rapid rise in the death
·Many children are and water supply ·Increased rate.
needed to work on the ·Improvements in food industrialisation and
land and support production mechanisation meaning The question could be
parents in old age. ·Improved transport fewer labourers asked is the second
(move food/ doctors) ·Increase desire for group in stage 5 or
High death rates ·Decrease in child material possessions returning to stage 1?
(especially children) mortality than large family
because: ·Emancipation of
·Disease and plague women meaning they
·Famine, uncertain food can follow their own
supplies, poor diet careers.
·Poor hygiene (These changes have
·Little medical science been slow in UK yet
quick in Asia etc)…read more
Population pyramids and the
Drawing a population pyramid is a good way to show the structure of a
High birth rate, Still a high birth rate, Declining birth rate, Low birth rate, low
rapid fall in each fall in death rate as low death rate, death rate, higher
upward age group more living in middle more people living dependency ratio,
due to high death age, slightly longer to an older age. longer life
rates, short life life expectancy. expectancy.
Stage 5 = more
convex than stage
4. Low and falling
birth rate, falling
fertility rate, ageing