POPULATION GROWTH

Concept

 In human geography, population growth is the increase in the

number of individuals in a population.
 Population growth (positive or negative) is caused exclusively by
the operation of fertility, mortality, and migration.
 Human population growth depends on the rate of natural
increase, or the fertility rate minus the mortality rate, and net
migration. The basics of demography can be reduced to this
formula:

(Births – Deaths) +/- ((In-Migration) – (Out Migration)) =

Population Change.
Determinants of Population Growth

Fertility

Mortality

Migration
 Fertility

 Fertility — occurrence of birth per year — is one of the most important

indicators of population growth.

 Fertility is a general term with many varieties. But two most important
measures of fertility are Crude Birth Rate (C.B.R.) per year and General
Fertility Rate (G.F.R.) per year.

 Crude birth rate is the number of birth per year per thousand, expressed
by the formula: CBR = B/P × 1,000
where B is number of birth/year and P is the total population. This measure
gives us the idea of net increase of population per year in a region.

 The General Fertility Rate or G.F.R. is, however, considered only for
reproductive females. It is expressed by the formula: GFR = B/P × 1,000
where B is the no. of birth per year while P refers to the number of
productive women.
 Mortality

 Mortality is the passing away of living being, expressed by crude

death rate (C.D.R.) per thousand per year, i.e.,CDR = D/P ×
1,000
where D is the number of deaths per year and P is the number of
population.

 Mortality is a vital determinant of population growth and indicates

general health, living standard, economic condition, nutrition and
degree of development of the respective society.

 Low mortality rate reflects improved health facility, low child

mortality, and effective preventive measures against epidemics.
 Migration

 Migration is shifting of people from one place to another for

residential and occupational reasons.

 Migration may be of two types — in migration or immigration

and out-migration or emigration. Migration, therefore, is
reallocation of human resources that eventually disrupts normal
population growth.

 Push factors are liable for out-migration which includes war,

famines, political unrest, economic disorder, ethnic conflict etc.
Pull factors invite in-migration when more financial opportu-
nities and political stability exist at a region.
History and Evolution of Global Population Growth

The origin of Homo sapiens and Paleolithic man dates back to 1

million years. Since then, growth of world population had gone
through several transformations. The entire history of human
population growth can be sub-divided into 4 major phases.

These are:
1. Pre-historic phase — up to 6,000 B.C.
2. Neolithic phase – 6,000 B.C. to 0 B.C.
3. Historical phase — 1 A.D. to 1650
4. Modern phase — 1650 onwards.
 Pre-historic Phase — up to 6,000 B.C.

 The growth of population was restricted by constant fierce battle

with hostile environment, epidemics, hunger etc.

 After the end of glacial age, at 10,000 B.C., human population

possibly reached 100,000 to 1 million mark.

 Since then, human race started to migrate to different corners of

the globe.
 Neolithic Phase — 6,000 B.C. to 1 A.D.

 This period witnessed comparatively larger population growth

and population increased to 5 million in 6,000 B.C., and to 256
million in 1 A.D.

 In this period, the development of agriculture and livestock

ranching encouraged spread of population from Mediterranean
and South-West Asia to Central Asia, China, India and even in
Far East Asia.

 To combat famines and epidemics, population growth rate was

very high, along with high mortality rate from 6,000 B.C. to 0
A.D.
 Historical Phase— 1 A.D. to 1650 A.D.

 At the beginning of Christian era, agricultural practices were

well-entrenched in large parts of the world.

 The estimated population of 256 million in 1 A.D. increased to

400 million in 1300 A.D. It finally rose to 500 million in 1650 —
at the start of Industrial Revolution.

 The entire period (1 A.D. to 1650 A.D.) had experienced

population growth rate of 0.1% per annum.
 Modern Phase—1650 Onwards

 Since the beginning of Industrial Revolution, global population growth rate

experienced a sudden dramatic and spectacular growth.
 In between 1700 A.D. and 1800 A.D. population was doubled, registering a
growth rate of 0.5% per annum, five times more than the previous century.
 In between 1800 and 1900 A.D. net addition of population was another 400
million and world population increased to 1.6 billion from 1.2 billion. The
average annual increment was 0.6% per annum.
 1900 to 1930 —only 30 years — experienced another addition of 400 million
people, with average annual growth of 1.07% per year.
 Between 1930 to 1950, net addition was 500 million and population reached 2.5
billion.
 Between 1950 to 1970, growth rate was a staggering 2.06% per year. Global
population touched 3.7 billion mark.
 In 2000, population touched a whopping 6 billion mark with a yearly growth rate
of 1.4% per annum.
 Present Trend

 The global population is still increasing at an alarming rate with

an annual addition of over 8 cores (81 million) people per year.

 The gradual lowering of fertility rate and increase of life

expectancy has enabled developed countries to stabilize
population growth.
 Types of population growth

 Exponential growth: When a quantity increases by a constant amount

per unit time e.g. 1, 3, 5,7 etc. it is called linear growth. But, when it
increases by a fixed percentage it is known as exponential growth e.g. 2,
4, 8, 16, 32 etc.

 Doubling time: The time needed for a population to double its size at a
constant annual rate is known as doubling time. It is calculated as follows:
Td = 70/r
where Td = Doubling time in years
r = annual growth rate
 Total Fertility Rates (TFR): It is one of the key measures of a
nation’s population growth. TFR is defined as the average
number of children that would be born to a woman in her lifetime
if the age specific birth rates remain constant.
 Infant mortality rate: It is an important parameter affecting
future growth of a population. It is the percentage of infants died
out of those born in a year.
 Zero population growth (ZPG): When birth plus immigration in
a population are just equal to deaths plus emigration, it is said to
be zero population growth.
 Male-female ratio: The ratio of boys and girls should be fairly
balanced in a society to flourish.
 Life expectancy: It is the average age that a new-born infant is
expected to attain in a given country. The average life expectancy,
over the globe, has risen from 40 to 65.5 years over the past
century.
 Demographic transition: Population growth is usually related to
economic development. There occurs a typical fall in death rates and
birth rates due to improved living conditions leading to low
population growth, a phenomenon called demographic transition. It
is associated with urbanization and growth and occurs in four
phases:

(a) Pre-industrial phase characterized by high growth and death rates

and net population growth is low.
(b) Transitional phase that occurs with the advent of industrialization
providing better hygiene and medical facilities and adequate food,
thereby reducing deaths. Birth rates, however, remain high and the
population shows 2.5-3% growth rate.
(c) Industrial phase while there is a fall in birth rates thereby lowering
growth rate.
(d) Post industrial phase during which zero population growth is
achieved.
 Three types of population situation

Under population:
 Under population exists when a population is too small, therefore unable to
fully utilize the available resource endowments.

 Under population is also characterized by a situation where the available

resources are capable of supporting a much larger population with no reduction
in living standards.

 The situation is found in regions of low technical development such as

equatorial Congo, Amazon River basin or the rich Prairie region of North
America.
Optimum Population:
 The optimum population is a concept where the human population is
able to balance maintaining a maximum population size with optimal
standards of living for all people.

 Optimum population has been defined as that size of population

enabling per capita output of the maximum orders accompanied by the
highest possible standards of living under a given set of economic and
technological conditions.

 Thus optimum population yields highest quality of life, which means

each person has access to adequate food, water, energy and air of
highest quality, adequate medical care, recreational facilities and
cultural outlets.
OVER POPULATION:
 The term ‘overpopulation’ means too great a population for a
given region to support. There may be two causes:
(i) population growth exceeds the existing resource base;
(ii) existing resources have been depleted.

 The situation of overpopulation displays the following socio-

economic characteristics: high unemployment, low incomes, low
standards of living, high population density, malnutrition and
famine.
Population Explosion:
 There has been a dramatic reduction in the doubling time (the time
needed for a population to double its size at a constant annual rate) of
the global human population. In the 20th century, human population
has grown much faster than ever before.

 Population explosion is causing severe resource depletion and

environmental degradation. Our resource like land, water, fossil fuels,
minerals etc. are limited and due to overexploitation these resources
are getting exhausted.

 Even many of these renewable resources like forest, grassland etc.

are under tremendous pressure. Industrial and economic growth are
raising our quality of life but adding toxic pollutants into the air,
water and soil. As a result, the ecological life support systems are
getting jeopardized.
Causes of Overpopulation or Population Explosion

 Decline in the Death Rate:

The fall in death rates that is decline in mortality rate is one fundamental causes
of overpopulation. Owing to the advancements in medicine, man has found
cures to the previously fatal diseases. The new inventions in medicine have
brought in treatments for most of the dreadful diseases. This has resulted in an
increase in the life expectancy of individuals. Mortality rate has declined
leading to an increase in population.
 Rise in the Birth Rate:
Thanks to the new discoveries in nutritional science, we have been able to bring
in increase in the fertility rates of human beings. Medicines of today can boost
the reproductive rate in human beings.
 Migration:
Immigration is a problem in some parts of the world. If the inhabitants of various
countries migrate to a particular part of the world and settle over there, the area
is bound to suffer from the ill effects of overpopulation. If the rates of
emigration from a certain nation do not match the rates of immigration to that
country, overpopulation makes its way.
 Lack of Education:
Illiteracy is another important cause of overpopulation. Those lacking education
fail to understand the need to prevent excessive growth of population. They are
unable to understand the harmful effects that overpopulation has.
 Poverty
Due to poverty, population is increased in developing countries. People lives in
slum, uses their children as a tool, to earn money, hence they always try to
increase the number of children in their families.
 Other Causes
Apart from the above, following are other causes of overpopulation
1- Social compulsion of Marriage
2- Ambition of big family
3- Betterment in economic position
4- Joint family system,
5- Arrival of Refugees etc.
Effects of Overpopulation or population explosion
 Problem of Investment Requirement:
Indian population is growing at a rate of 1.8 percent per annum. In order to achieve
a given rate of increase in per capita income, larger investment is needed. This
adversely affects the growth rate of the economy.
 Problem of Capital Formation:
Composition of population in India hampers the increase in capital formation.
High birth rate and low expectancy of life means large number of dependents in
the total population.
 Effect on per Capita Income:
Large size of population in India and its rapid rate of growth results into low per
capita availability of capital.
 Effect on Food Problem:
Rapid rate of growth of population has been the root cause of food problem.
People do not get sufficient quantity of food due low availability of food which
affects their health and productivity.
 Problem of Unemployment:
Large size of population results in large army of labour force. But due to shortage
of capital resources it becomes difficult to provide gainful employment to the
entire working population.
 Low Standard of Living:
Rapid growth of population accounts for low standard of living. Even the bare necessities of life are not
available adequately.
 Poverty:
Rising population increases poverty in developing countries. People have to spend a large portion of
their resources for bringing up of their wards. It results into less saving and low rate of capital
formation.
 Population and Social Problems:
Population explosion gives rise to a number of social problems. It leads to migration of people from
rural areas to the urban areas causing the growth of slum areas. People live in most unhygienic and
insanitary conditions.
 More Pressure on Land:
Rising rate of population growth exerts pressure on land. On the one hand, per capita availability of land
goes on diminishing and on the other, the problem of sub-division and fragmentation of holdings
goes on increasing. It adversely affects the economic development of the country.
 Pressure on Environment:
Population explosion leads to environmental degradation. Higher birth rate brings more pollution, more
toxic wastes and damage to biosphere. Briefly speaking, population explosion hinders the economic
development. It should be controlled effectively.
Measures to Control Population
Social Measures:
Population explosion is a social problem and it is deeply rooted in the society. So
efforts must be done to remove the social evils in the country.
 Minimum age of Marriage:
As fertility depends on the age of marriage. So the minimum age of marriage
should be raised. In India minimum age for marriage is 21 years for men and 18
years for women has be fixed by law.
 Raising the Status of Women:
There is still discrimination to the women. Women should be given opportunities
to develop socially and economically. Free education should be given to them.
 Spread of Education:
The spread of education changes the outlook of people. The educated men prefer
to delay marriage and adopt small family norms.
 Change in Social Outlook:
Social outlook of the people should undergo a change. Marriage should no longer
be considered a social binding. Issueless women should not be looked down
upon.
Economic Measures:
 More employment opportunities:
The first and foremost measure is to raise, the employment avenues in rural as
well as urban areas.
 Development of Agriculture and Industry:
If agriculture and industry are properly developed, large number of people
will get employment. When their income is increased they would improve
their standard of living and adopt small family norms.
 Standard of Living:
Improved standard of living acts as a deterrent to large family norm. In order
to maintain their higher standard of living people prefer to have a small
family.
 Urbanization:
It is on record that people in urban areas have low birth rate than those living
in rural areas. Urbanization should therefore be encouraged.
Other Measures:
 Late Marriage:
As far as possible, marriage should be solemnized at the age of
30 years.
 Self Control:
According to some experts, self control is one of the powerful
methods to control the population. It is an ideal and healthy
approach and people should be provided to follow. It helps in
reducing birth rate.
 Family Planning:
This method implies family by choice and not by chance. By
applying preventive measures, people can regulate birth rate.
 Publicity:
The communication media like T.V., radio and newspaper are the
good means to propagate the benefits of the planned family to the
uneducated and illiterate persons especially in the rural and
backward areas of country.
 Incentives:
The govt. can give various types of incentives to the people to adopt
birth control measures.
 Employment to Woman:
Another method to check the population is to provide employment
to women. Women should be given incentive to give services in
different fields.
 T H AN K TO U

P R E PAR E D B Y-

S AR M I S H T H A S A H A

T. H . K . JA I N CO L L E G E