At the beginning of the nineteenth century, the total world population crossed the threshold of 1 billion people for the first time in the history of the homo sapiens. Since then, growth rates have been increasing exponentially, reaching staggeringly high peaks in the 20th century and slowing down a bit thereafter. The total world population reached 7 billion just after 2010 and is expected to reach 9 billion by 2045. This paper first charts the differences in population growth in the newly formed district of Buhana in Rajasthan. Next, the mechanisms behind unprecedented population growth and sex ratio are explained and plausible scenarios for future developments are discussed. Crucial for the long-term trend will be the rate of decline of the number of births per woman, called total fertility. Improvements in education, health facilities and women's status is indeed a boost up But, in all scenarios, the population will continue to grow for some time due to population momentum. Finally, the paper outlines the debate about the consequences of the population explosion, involving poverty and food security, the impact on the natural environment, and migration flows.

Keywords: Fertility, family planning, world population, population growth, demographic transition, urbanization, population momentum, population projections