Population explosion

What is population?

Population is defined as a group of individuals living in the same given area and capable of interbreeding and sharing genetic material.

Challenges posed by population

The large human population poses a big challenge to the environment through two main factors:

• The number of people and
• The impact of each person on the environment. In last 40 years, the world human population has doubled from 2.5 billion to more than six billion.

In the same period, in our country, it has risen from 431 million to 1027 million.

Why study population?

In economic terms, a population constitutes of both consumers as well as producers. Its study helps us to:

provide data on the total manpower available now and in future; estimate the total amounts of goods/ services required currently and in future; to promote cultural/regional/linguistic harmony.

Major periods of human population growth Through history, four major periods of human population growth worldwide can be traced:

• An early period of hunters and gatherers: At that time, the total population was only a few million.
• The period of rise of agriculture: This period led to greater density of people and caused the first major rise in human population.
• The industrial revolution: This resulted in better food supply, improved healthcare which, in turn, led to rapid rise in the population
• The present: When the population is slowing down in the wealthy and industrialised nations but is still growing rapidly in developing and underdeveloped nations.

Demographic features

The study of various aspects of a population is called demography. The major parameters used for the study of demography are size, growth, age structure, demographic transactions, fertility, birth rate, death rate, standard of living, growth rates and migration.

Size

The size of a population is measured in terms of the number of people of a region/country. The population count by census 2001, by the Registrar General of India, shows that India’s population is 102 crore. The population in the last decade 1991-2001 rose more than 18 crore. Compare to the maximum growth in the decade 1901-1911 decade, which was only 1.36 crore. Are we as a nation providing every individual essential goods/services? This is a very important environmental issue that our country faces today.

Growth of the population: The growth of a population at different times can be expressed in terms of growth rates. The growth rate, that is the rate of change per 1000 individuals, determines the change in population.

Calculation of growth rate of population

For the calculation of growth rates, we have to first calculate the birth rate and death rate. This can be done as follows:

Birth rate: Rate at which births occur in a population Let N = Total number of individuals in the population, B= Number of births per unit time by the total population ‘N’, b= Birth rate or total no of individuals added in the population.b= B/N

Death rate: Rate at which death occur in population Let N = Total number of individuals in the population, D = Total number of deaths per unit time in the population ‘N’.d = death rate Then, d = D/N

Growth rate

The growth rate (g) is the result of the number of births minus the number of deaths per unit time divided by the total number of individuals in the population.

To calculate the growth rate,Let B = total number of births per unit time, D = total number of deaths per unit time. G = the difference between the total births and the deaths of the individuals per unit time. Then, N = The total number of individual in the population. g = growth rate for that unit of time I.e. g = G/N or the difference between the total births and the deaths of the individuals per unit time. Therefore g= B-D/N or G/N

Mortality

Mortality refers to the death of individuals. In a population, members die due to various reasons such as, malnutrition, disease, old age, accidents, natural calamities and war etc. It is equal to death rate.

Natality

Natality is an expression of the addition of new individuals in a population. It is equivalent to birth rate.

Migration

Migration means the movement of individuals of a population. The movement of theindividuals out of one’s own country is called emigration. Emigration may occur because of various reasons, viz: better job opportunities elsewhere, better education facilities elsewhere, illegal transfer, war, natural calamities, internal disturbances in the host country.

For example: The movement of an individual from one region of a country into another region of the same country is called internal immigration. Does internal immigration affect the population size of the country? The internal migration within the country is usually from rural areas to urban sector.

The population in rural areas rise sharply compared to urban areas. The lack of demand for labour in agriculture, increased job opportunities in cities and better education facilities, health care, living conditions are some of the key factors influencing internal migration from rural areas to urban areas.

In economic terms, population can be categorized as follows:

• If the resources of a region are more than adequate for its people, the region is recognised as under-populated
• If the resources are just enough, then the region is said to have optimum population
• If the resources get overused and it is not possible to produce the same amount of goods or services for every individual of the region, the region is over-populated
  

Therefore, it is not only the number of individuals but also the quality of life in a region that counts. Disparities in quality often lead to social tension/ imbalances.