What was the world's total population during the $2011$ census?

$Statement 1$: Over-population has become a serious problem in the developing countries.
$Statement 2$: It does not exhaust natural resources, causes unemployment and pollution.

What are the probable factors that contributed to the population explosion in India?

What is the scientific study of human populations called?

The socio-religious cause of population growth is:

Phenomenal and rapid increase of population in a short period is called