Synopsis The world population is the total number of humans on earth at a given time. Different regions have different rates of population growth, but in the unusual case of the twentieth century, the world saw the biggest increase in its population in human history due to medical advances and massive increase in agricultural productivity made by the Green Revolution. Undoubtedly, the increasing population alarmingly has become a great challenge which requires substantial resources to meet with. The book comprehensively discusses with almost all the possible concerned facts pertaining to population challenge and world crisis. The book would therefore be a useful reading material for academics researchers, policy-makers, students and public at large.