Over the past 160 years our numbers have doubled and doubled and almost doubled again. Never before have we seen such a huge rise in human population in so few generations. Never again will we. Today our population growth is slowing down. In 1859 Charles Darwin wrote of “the numerous recorded cases of the astonishingly rapid increase of various animals in a state of nature, when circumstances have been favorable to them during two or three following seasons.” Using examples ranging from minuscule seedlings to giant elephants, he discussed the very rare cases in nature when exponential population growth occurred in a species. In fact, the best example he could have picked would have been that of his own species, humans, who at that time were just beginning their own unprecedented, exponential, worldwide increase in numbers.
Today slowdown (a word first used in the 1890s, meaning to go forward more slowly) affects far more than our rate of population growth. It affects almost every aspect of our lives. Our current slowdown represents a huge challenge to the expectation of acceleration, and a step into the unknown. To what extent are our current belief systems (economic, political, and otherwise) built on assumptions of rapid future technological change and perpetual economic growth? Accepting that a slowdown is upon us will require us to shift our fundamental view of change, innovation, and discovery as unalloyed benefits. Will we be able to accept that we should stop expecting ceaseless technological revolutions? The possibility that we might not sensibly be able to do so is itself frightening. What mistakes will we make if we assume that slowdown is unlikely and new great shifts lie just around the corner? What will happen if things stay much the same as they are now while the rate of change simply slows down?
Imagine that you have spent your life on a speeding train and you suddenly feel the brakes being applied. You would worry what was about to happen next. Now imagine that not just you but all the people you know— as well as their parents, grandparents, and great-grandparents, as far back as anyone can remember—have all lived on that very same speeding train, and that the train has been accelerating for virtually all of their lives. For you, hurtling forward at breakneck speed is comfortingly normal, but now you can begin to feel the slowdown, a new and frightening feeling. However, because the train is still rushing forward, people all around you are still talking of acceleration—the increasing pace of change—although in reality the train is no longer going ever faster. Something has changed. Out of the window the landscape is going by less quickly; everything is slowing down. An era is ending.
It is because we have so few examples of slowdown to draw on from the past couple of centuries that we find our times especially confusing today. However, slowing down is a very good thing—and the alternative is unimaginably bad. If we do not slow down, there is no escape from imminent disaster. We would wreck our very home, the planet we live on. We need to slow down because we have nowhere else to speed to without catastrophic consequences. Slowdown means we need not fear the nightmare scenario of worldwide famine depicted at the end of Paul and Anne Ehrlich’s 1968 book The Population Bomb, in which they concluded of India that its people should be allowed to starve: “Under the triage system [suggested by them] she [India] should receive no more food.” This kind of concern and brutal conclusion were rife in the recent past. Images of out-of-control acceleration became commonplace. For instance, Joel E. Cohen, a mathematical biologist, wrote in 1992:
Back in 1970 Ansley Coale, a demographer at Princeton, observed that the population of the United States had increased by half since 1940. At that growth rate, he calculated, the US population would reach a billion shortly before the year 2100. Within six or seven more centuries we would reach one person per square foot of land area in the United States, and after about 1,500 years our descendants would outweigh the Earth if they continued to increase by 50 percent every 30 years. We can even calculate that, at that rate of increase, our descendants would, in a few thousand years, form a sphere of flesh whose radius would, neglecting relativity, expand at the velocity of light.
Ansley Coale was making his calculations just a year or so after the point when what he was measuring ceased to accelerate any further. By the early 1990s we began to worry less about acceleration. It was then that we began to realize that continued acceleration was no longer possible.
Now take a step backward.
Look at what is happening all around you.
It is New Year’s Day 2019. I have just listened to an early-morning radio discussion about how, if we humans planned a trip to the planets of Uranus and Neptune this year and began working on that plan straightaway, we could get a spaceship there by 2043. It would take almost a quarter of a century just to see those planets up close.
We are trapped by time—and space. It simply takes too long to get to anywhere else. We are stuck here, on Earth, for (hopefully) a very long time to come. Fortuitously, human population growth began to slow down dramatically in the late 1960s (ironically, around the very same time as the first human walked on the moon). Th ere is now nowhere where the population is any longer accelerating. Deceleration has become the norm, and today in much of Europe, the Far East, and in large parts of the Americas, total human population numbers are falling.
A slowdown in population does not necessarily mean immediate stability, but rather stability to come. It is most likely that a century from now the average number of children in a family will be fewer than two. Slowdown means that within a century the new global norm will be a slowly shrinking total planetary human population. This would also mean a continuously aging population for many decades to come, but the rate of aging will itself also slow in the near future as the rise in human life expectancy slows down. The age of the world’s oldest person has not increased in the past twenty years.
Of course, as the slowdown progresses, there will be shocks and many surprises which, by definition, are entirely unpredictable; but it is now sensible to admit that the process has begun. Understanding that to be true requires looking at the recent past and present very differently from how we have become accustomed to viewing our times. But first, we must consider what continuing to speed up would look like.
From Slowdown by Danny Dorling. Published by Yale University Press in 2021. Reproduced with permission.
Danny Dorling is the Halford Mackinder Professor of Geography at the University of Oxford. His previous books include Inequality and the 1% and The Equality Effect.