Environmental collapse due to overconsumption of natural resources is inevitable, even without climate change, depletion of arable land, bleaching of coral reefs, acidification of the oceans, etc.  But if there’s one bright spot in all this doom and gloom, it’s the worldwide change in attitude towards having children.  People, and more specifically women, are having fewer children by choice, and the reasons are positive.  The world’s current estimated population is close to eight billion (7.94), but based on several factors, we may peak at 8.5 billion and begin to decline.

First, there’s the World Population Historical Table from Worldometers.  The total raw number of people has continued to increase, but the rate of increase is lessening.  For example, the average number of new people born per year was 91 million in 1990 (from 5.3 billion), but was only 81 million in 2020 (from 7.8 billion). The annual increase peaked at 2.07% in 1970 but since it was 1.82% in 1990, the annual rate of increase continutes to drop, now at 1.05% in 2020.

How did we produce fewer new children despite 2.5 billion more people to have them?  Mass deaths?  No.  From a reduced number of pregnancies.  People are choosing to have fewer children.  In the cases of China, India, South Korea, and possibly others with sex selective abortions, there are a disproportionate number of men and a shortage of women.  And some of these women are choosing their career over marriage and children (i.e. China’s “left over women”, age 30+ who never married).

Historically, families had many children because they expected some to die.  Like turtles, more offspring meant more competition for resources but a greater chance of one or more surviving.  Thanks to other factors, people are behaving more like elephants, having fewer children yet able to invest more in their care and survival.  The same number of kids are surviving to adulthood, but with fewer deaths and trauma for the parents.  Their chances increased because of improved medical care, vaccination, increased family income, employment opportunities, education for women and children, among others.

The video below goes into detail about each factor, and where the changes in birth rates are happen.  Unsurprisingly, the greatest declines are in Europe, North America, and Oceania.  However, everywhere else the same declines are occuring at the same rate.  Birth rates in Africa now are still the highest, but the rate in most African countries now are lower than the rates in European countries century ago.  Where I disagree with him are contributing factors he leaves out (e.g. democracy, industrialization, migration, common languages), but the numbers he presents matches his source, Our World In Data.

In East Asian countries (esp. Japan, South Korea, China) industrialization was common while political systems varied widely, yet the birth rates are the same. Attitudes towards abortion were not, with sex selective abortion being common practice in South Korea and China thirty-odd years ago, but not in Japan.

Also noticeable in Africa is the strip of countries along the east coast where the rates declined the most.  Several have a common language (Swahili) which makes it easier for ideas to spread across political borders because there’s only one barrier, not two.  Being bookended by the most democratic nations in Africa (Kenya and South Africa) probably helps.  Also of note, other than Kenya, all those countries have low or unmeasurable rates of Female Genital Mutilation, another sign of education in a society.

Something else shown by the World Population Historical Table from Worldometers. (also linked above) is the increasing median human age worldwide.  For centuries, the average was in the low 20s.  But since 1990, the median has increased and is now over 30, likely the first time ever.  And the median age will continue to rise.

The world population is ageing (Researchgate), and those of reproduction age (20-35) are having fewer children.  (This Researchgate chart is from 2017, so take into account the bar for each age is now one older.)  Those children in the chart age 0-15 were born to the bulges aged 30-39.  The smallest bands in the graph (age 15-24, now age 20-29) are the Zoomers, and they aren’t having kids.  There are declining birth rates in dozens of countries worldwide.  I would really like to see a new version of this table in 2022.  How small is the 0-4 age group now?

From the BBC (2020):

Fertility rate: ‘Jaw-dropping’ global crash in children being born

The world is ill-prepared for the global crash in children being born which is set to have a “jaw-dropping” impact on societies, say researchers.

Falling fertility rates mean nearly every country could have shrinking populations by the end of the century.

And 23 nations – including Spain and Japan – are expected to see their populations halve by 2100.

Countries will also age dramatically, with as many people turning 80 as there are being born.

[. . .]

As a result, the researchers expect the number of people on the planet to peak at 9.7 billion around 2064, before falling down to 8.8 billion by the end of the century.

“That’s a pretty big thing; most of the world is transitioning into natural population decline,” researcher Prof Christopher Murray told the BBC.

“I think it’s incredibly hard to think this through and recognise how big a thing this is; it’s extraordinary, we’ll have to reorganise societies.”

It has nothing to do with sperm counts or the usual things that come to mind when discussing fertility.

Instead it is being driven by more women in education and work, as well as greater access to contraception, leading to women choosing to have fewer children.

In many ways, falling fertility rates are a success story.

It’s both a success story, and a solution to a problem.  The fewer consumers of resources there are, the easier the burden we place on the environment.  Less impact means fewer deaths due to climate impacts, starvation, wars for resources, disease, etc.

An ageing and shrinking population is the gentle solution to our environmental problem.