It took the entire history of human kind for the population to reach one billion around 1810. Just 120yrs later this doubled to 2 billion people (1930). Then 4 billion within 45yrs (1975). The number of people has raised from 4.4 billion in 1980 to 5.8 billion by 1997 and 7 billions today and it is estimated that the population could double again to 11 billion in less than 40yrs. This means that more people are adding each day than at any other time in human history.
According to report by the United Nation Population Fund (UNPF), total population is likely to reach 10 billion by 2025 and grow to 14 billion by next century.
Both death rates and birth rates have fallen, but death rates have fallen faster than birth rates. There are about 3 births for one death with 1.6 births for one death in most developed countries and 3.3 births for one death in less developed countries. The world’s population is increasing a billion for every dozen years.