Answer:
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.
Explanation:Rapid growth has led to uncontrolled urbanization, which has produced overcrowding, destitution, crime, pollution, and political turmoil. Rapid growth has outstripped increases in food production, and population pressure has led to the overuse of arable land and its destruction.