World population

Question 5

The world population is over 6.5 billion. According to the United Nations, this figure was reached on 19 December 2005. But can we be sure? What is the margin of error?

Answer 5

We have population figures for all countries of the world, though their accuracy varies. They enable us to estimate the total number of humans on earth to within a few percentage points. The figure of 6.5 billion may have been reached one or two years before 2005, or one or two years after. We nonetheless have a clear picture of overall demographic trends and can confidently predict that the world will count between 8 and 9 billion people in 2050.