The world’s population in 2100 could be no higher than it is today
The average woman in Niger has seven children. The average South Korean has barely one. The future size of the world’s population depends largely on how quickly child-bearing habits in places like Niger become more like those in South Korea. If women in high-fertility countries keep having lots of babies, the number of people will keep swelling. The sooner they curb their fecundity, the sooner it will peak and start falling.
The un projects that fertility will fall gradually and that lifespans will increase, so the world’s population will rise from 7.7bn today to 11.2bn by 2100. (This is its best estimate; the un says it is 95% confident that the true figure will lie between 9.6bn and 13.2bn.) Opinions are divided over the effects of such growth. For some, a more crowded planet will be an environmental disaster. For others, those billions of extra brains will help humanity devise ever more cunning solutions to its problems.
