Later this year—any day now really—the global population is projected to cross eight billion people. The United Nations recently pegged the date as Nov. 15, but we don’t know with any exact precision.
Since the 1960s, when the global number of people first hit three billion, it has taken a bit over a decade to cross each new billion-person milestone, and so it might seem natural to assume that nine billion humans and then 10 billion are, inexorably, just around the corner. That is exactly what the latest population projections from the U.N. and the U.S. Census Bureau have calculated.
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