This rapid growth increase was mainly caused by a decreasing death rate (more rapidly than birth rate), and particularly an increase in average human age. By 2000 the population counted 6 billion heads, however, population growth (doubling time) started to decline after 1965 because of decreasing birth rates.
Similarly one may ask, why is the population declining?
A population decline (or depopulation) in humans is a reduction in a human population caused by short term events such as pandemics, wars, famines or other catastrophes, or by long-term demographic trends, as in sub-replacement fertility rate, or persistent emigration.
Furthermore, is world population declining?
In 2017 the UN predicted a decline of global population growth rate from +1.0% in 2020 to +0.5% in 2050 and to +0.1% in 2100.
Can we successfully apply the concept to human population growth?
Humans. The application of the concept of carrying capacity for the human population, which exists in a non-equilibrium, has been criticized for not successfully being able to model the processes between humans and the environment.
How many people can the world hold?
Most contemporary estimates for the carrying capacity of the Earth under existing conditions are between 4 billion and 9 billion. Depending on which estimate is used, human overpopulation may have already occurred. Nevertheless, the rapid recent increase in human population has worried some people.