This is a useful introduction to the next 70 years. The authors Darrell Bricker and John Ibbotson trace the debates about total human population, they side for good reasons with the view that the media UN demographic projections are too high, and they speculate on some of the effects that decreasing population will have on economic growth (bad), global warming (good) , and the extinction of small cultures (ongoing).
The argument is simple: women are becoming less fertile – having fewer babies – under the influence of higher education, moving to cities, greater aspirations, and the decline of social control of their reproductivity. This decline is occurring nearly everywhere, including in non-industrial societies, advanced industrial societies, and regardless of whether the people in question are Catholic, Protestant, Buddhist, secular, or Islamic. The fertility decline is occurring with especial speed in Islamic societies, and formerly strongly Catholic ones.
This is counter to what you have been taught in university back in the days of the Club of Rome report (1972) and in the doomist press. Births are below replacement rate (2.1 per woman) in most parts of the world. Afghanistan, Pakistan, and Mali are exceptions, though birth rates will fall there shortly, too. The point of demographics is that it correctly predicts the shape of societies for decades to come precisely because people tend to live by statistically valid durations of time. Lifespans are calculable.
Overall, the global average length of life has doubled to 70 years since 1900.
The UN predicts in its medium growth scenario a global population in 2100 (roughly 80 years away) at 11.2 billion, at which point it holds stable and then starts to shrinks. The low variant of UN projections say that the world population will peak at 8.2 billion around 2050 and decline to 7 billion, where we are now, by 2100.
A good portion of the argument of Bricker and Ibbotson is that the low variant will prove to be the correct one. I encourage you to read the argument.
The authors indulge themselves in later chapters with some attacks on nativism and Trump’s policies, which express Toronto-centric Upper Canadian snobbery and fail to address that the issue for the US is illegal immigration. Legal immigration to the United States continues to be high and is socially approved of, at about 1.1 million a year. Undocumented immigration has amounted over the years to more than 10.5 million US residents, and this is what excites the antipathy of the US citizenry.
They do venture to observe that declining world population, coupled with roughly stable energy use per person, will alleviate the global warming crisis (as they would see it). “Urbanization, innovation, and depopulation might be the best solution to halting the march of climate change.” (p.231)
However, the chief merit of this book is to draw attention to the shape of the next 80 years, as population rises until mid-century and begins to drop, in some cases precipitously, by 2100.
The same material is discussed from a deeply religious (meaningful) viewpoint in David Goldman’s How Civilizations Die (and Why Islam is Dying too). Both books start with UN statistics on population, but the resemblance ends there. Goldman links fertility, past and future, to the tenacity to which people hold to their religious creeds. This will be an unwelcome thought to the purely secular minds of Ibbotson and Bricker, and many other reasonable people. Yet of the subject of the world’s population interests you, Goldman’s interpretation of the facts evokes much deeper issues than urbanization and female empowerment. Says Goldman:
“Two cultures are contending at the family level throughout the world: secular modernity and renewed faith. Secular families have few children and religious families have many. That means that in each generation, religious families will increase in number and secular families will diminish” (at p 197)
Thus, says Goldman, the path out of secular population decline will necessarily require a change of views regarding family, women’s roles, fatherhood, and the really important issues of life. These are what I mean by the word “religion”. I do not see anything like this happening soon, and maybe it will never happen. By 2050, in a world that is shrinking in population, radical alternatives to population decline may seem more achievable and desirable. Or maybe we will have been assimilated by the Borg by then.