At the beginning of the 20th century the population of the world was 1. 7 billion. At the end of that century, it had soared to 6 billion. Recent estimates suggest that it will be nearly 8 billion by 2025 and 9. 3 billion by 2050. Almost all of this increase is forecast to occur in the developing regions of Africa, Asia and Latin America. For what economists have had to say about this, see demographics.