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The world's population reached 8 billion Nov. 15, 2022, a milestone (里程碑) in human development. While it took the world's population 12 years to grow 7 to 8 billion, it will take about 15 years-until 2037-for it to 9 billion. It's a sign that the growing speed of the world's population is slowing . The world's population will be the at around 10. 4 billion in the2080s and keep at that level until 2100. So far, China India have been the most populated countries in the world, with about 1. 4 billion people each.