In Pics | World's 10 most populous countries (2022)The World population has just hit the 8-billion mark on November 15, doubling in about 48 years from the time it hit the four billion mark in 1974, according to the UN. The report stated that it was also the fastest addition of 1 billion humans to the population. While the figure continues to swell, here we list the top ten largest contributors to the world population, according to Worldometer.