Older people – not children – will drive population growth in the 21st century
There can be no doubt that population growth is one of the greatest challenges of our time, but the recent piece in Wired Magazine, entitled ‘The Biggest Threat to the Earth? We Have Too Many Kids’, which argues that the only way to save the world is to stop making more humans, misses a key point. I don’t blame the author, for he is not alone. The Swedish statistician, Hans Rosling, describes it as ‘the biggest statistic that the world’s media ever missed.’
It is true that the number of children in the world doubled over the last 50 years to reach 2 billion, but that is as high as it is going to get. At the end of the century there will still be 2 billion under 15s globally. How is this possible, when the world population is set to grow from its present level of 7 billion to peak at 10 or 11 billion over the same time period? The simple answer is that people are living longer and having less children. Fertility is forecast to decrease from its present level of 2.4 children per woman to 2 children. This is because because the large number of people having less than two children more than balances out the smaller number who have 3 or more.
Right now we have 4 billion people under 30. If they each have one child – 2 children per couple – we get another 4 billion. Add in 2 or 3 billion over 60s, depending on how much longer people actually live, and that takes us to 10 or 11 billion.
Much of the Twitter commentary on the Wired piece focussed on judging those irresponsible enough to have large families, especially if they are single parents, or poor. Fuelled by righteous indignation, people propose limiting family size, or at least means testing it. It is worth considering that this indignation is misdirected. The UN projections show that it is not people having children that will increase population, but people getting older. We can only hope that the young people of the 2030s do not start to propose radical solutions to the problems of overpopulation, for those solutions will be directed not at the young but at the old. And those old people will be you and I.