The rate of increase of the world's population has become ever faster:‘Future population growth is highly dependent on the path that future fertility takes. In the medium variant, fertility is projected to decline from 2.6 children per woman today to slightly over 2 children per woman in 2050. If fertility were to remain about half a child above the levels projected in the medium variant, world population would reach 10.6 billion by 2050. A fertility path half a child below the medium would lead to a population of 7.6 billion by mid-century. That is, at the world level, continued population growth until 2050 is inevitable even if the decline of fertility accelerates (Population Division, Dept. Econ. & Soc. Affairs, UN Secretariat, 2004 Revision). See population projection.
Wolfgang Lutz et al. (2004) discuss expert argument-based probabilistic forecasting of population; Bongaarts and Bulatao (1999) Pop. & Devt. Rev. 25 quantify the relative contributions of fertility, mortality, migration, and age structure in projections for all countries of the world.
population in billions
Subjects: Earth Sciences and Geography — African Studies.