Hans Rosling, he of the famous TED Talk about washing machines, presents five reasons to be optimistic about the future of the world and its inhabitants, for the BBC Magazine. Here’s the opening entry, about population, a tricky subject that often makes fools of analysts:

“1. Fast population growth is coming to an end

It’s a largely untold story – gradually, steadily the demographic forces that drove the global population growth in the 20th Century have shifted. Fifty years ago the world average fertility rate – the number of babies born per woman – was five. Since then, this most important number in demography has dropped to 2.5 – something unprecedented in human history – and fertility is still trending downwards. It’s all thanks to a powerful combination of female education, access to contraceptives and abortion, and increased child survival.

The demographic consequences are amazing. In the last decade the global total number of children aged 0-14 has levelled off at around two billion, and UN population experts predict that it is going to stay that way throughout this century. That’s right: the amount of children in the world today is the most there will be! We have entered into the age of Peak Child! The population will continue to grow as the Peak Child generation grows up and grows old. So most probably three or four billion new adults will be added to the world population – but then in the second half of this century the fast growth of the world population will finally come to an end.”