In the ‘Origin of Species’, Charles Darwin described how a population explosion occurs. He called the events required – ‘favourable seasons’. Charles was not to know it, but such circumstances arose for his own species at around the time of his own birth. However, the favourable seasons for human population growth were not experienced favourably, with times of great social dislocation – ranging from small scale enclosure, right through to global colonisation.

Now those seasons are over we have experienced the first ever sustained slowdown in the rate of global human population growth for at least one generation. However, we are not just slowing down in terms of how many children we have, but in almost everything else we do (other than the rise in global temperatures we live with). Even the size of the rise in global student debt may now be slowing. If this is true – what does it mean? And what measurements suggest it is true?

in January 2019, the press reported that: “Jørgen Randers, a Norwegian academic who decades ago warned of a potential global catastrophe caused by overpopulation, has changed his mind. “The world population will never reach nine billion people,” he now believes. “It will peak at 8 billion in 2040, and then decline.”

Similarly, Prof Wolfgang Lutz and his fellow demographers at Vienna’s International Institute for Applied Systems Analysis now predict the human population of the planet will stabilise by mid-century and then start to go down.

And a recent Deutsche Bank report now suggests that the planetary population will be peaking at 8.7 billion in 2055 and then declining to 8 billion by century’s end.

In February a reviewer in the Times newspaper wrote that: “The world’s population may be about to contract” and questioned whether this might be good news, or not. So there is much to debate:

 

In this audio recording of a talk, Danny Dorling is speaking at the Cambridge University Scientific Society, on February 26th 2019, in the Pfizer Lecture Theatre of the Chemistry Department: