2. WHAT IS POPULATION ?
• Population is defined as a group of individuals belonging to the same
species , which live in a area of given time.
POPULATION DENSITY :
• It is expressed as the number of individuals of the population per unit area or
per unit volume . This varies in response to changes in the environment and
introduction with other living organism.
3. POPULATION GROWTH
• The rapid growth of the global’s population for the past 100 years
results from the difference between the rate of birth and death.
• In 1880, the global population was about 1 billion people . It took about 130
years(in 1930) to reach 2 billion. But the population reached to 4 billion within
45 years (in 1975). Now we have already crossed 6 billion and may have to
reach about 10 billion by 2050 as per the World Bank calculations.
• Increase in population = population growth
• CAUSES OF RAPID POPULATION GROWTH :
1) Population growth is due to decrease of death rate and increase in birth rate.
2) Availability of antibiotics, immunisation , increased food production, clean
water and air decreases the famine-related deaths and infant mortality.
3) Agricultural based countries, children’s are required to help parents in the
fields that is why population increases in the developing countries.
4. PROBLEMS ( ENVIRONMENTAL ISSUSES )
OF POPULATION GROWTH
1) Increasing demands for food and natural resources.
2) Inadequate housing and health services.
3) Loss of agricultural lands.
4) Unemployment and socio-political unrest.
5) Environmental pollution.
• Causes of population growth :
1) Fertility rates.
2) International migration.
3) Increase in climate change.
4) Impact on biodiversity loss.
5) Overexploitation of resources.