Question

Define demography. What are the reasons for population explosion since ${19}^{th}$ century? Describe the environmental impacts caused due to population explosion with the help of diagram.

Answer 1

The field of collecting, compiling and presenting information about population is called demography and the people engaged in this work are named as demographers.
Reasons for population explosion since $19th$ century:
Since the $19th$ century, discoveries of vaccination provides protections to many of the infectious agents, discovery of antibiotics is a major breakthrough in the medical history, improvements in agricultural techniques, improvements in the nutrition and better sanitation and personal hygiene brought about spectacular reductions in mortality, especially among infants and children. The birth rate has remained high. So the human population entered into exponential growth, as they were freed from natural enemies and other environmental restraints.

Increasing number of people put increasing demands on the environment, both through demands for resources and through production of wastes. Most of the human population survived through subsistence agriculture to meet their needs. After the modern medicines and industrial revolution, the death rate plummeted and population growth increased. The impact of rapid growth on a population that is largely engaged in subsistence agriculture has resulted in five basic alternatives to various degrees.
(i) people can subdivide farms among the children or intensify cultivation of existing land to increase production per unit area.
(ii) open up new land to farm.
(iii) move to cities and seek employment.
(iv) engage in objectionable activities for income.
(v) emigrate to other countries legally.
The rapid population growth especially affects women and children. Increasing the average wealth of a population affects the environment both positively and negatively.