Predicted declines in population hold major global challenges

Researchers have forecast that the global population will peak at 9.73 billion in 2064 and decline to 8.79 billion in 2120—a level significantly lower than previous estimates.1

Over this period the number of people over 80 will increase by over 600%, from 141 to 866 million, while the number of children under five years will decline by 41% from 681 million to 401 million.

The main determinant of the decreased 2120 population size is reducing total fertility rate, which is largely influenced by increasing educational attainment among women and access to contraception, the researchers said in the Lancet.1

In the context of a declining population “some countries will sustain their populations through …