August 21, 2022

Throughout history, although no other species on Earth has experienced such long term overall population growth, even before the recent population explosion, the human population kept slowly growing.

Yes, we recently had an unprecedented population explosion, driven by the near elimination of previously tragic rate of infant mortality, but against a background of more gradual long-term growth, many of us may have never even realised we just had a population explosion.

But what drove that long-term population growth even before the explosion, and what will now happen as the explosion ends?

Environment sensitive reproduction rates: parents instinctively seek maximum opportunities for kids.

Human birth rates are falling at a rate that has some fearing population collapse, but could this be a natural instinctive biological response to ensure optimum population of the future generation, rather than any cause for alarm?

Looking at nature, clearly it is not just the species with maximum children that survive as the fittest, but the species with the optimum number of children. Most species don't just multiply whenever possible at maximum rate like bacteria in petri dish and survival of the fittest doesn't just mean the species with the maximum children, it means the right number and at the right time.

Analysing mechanism that vary reproduction in other species may provide some interesting insights and possible answers to at least a large part of what is happing with human birth-rates that will determine whether our future is population is one of: continued growth, collapse, or stability, on a planet where population of all life is not growing.

Population Explosion: How did we get to 8 billion people?

Humanity has just experienced a population explosion. Whether you study population or believe we are overpopulated or not, the facts are that we have just had a population explosion.

Over two centuries of population reaching 50x higher than the historical long-term population growth, and even peaking at 100x higher than historical averages.

Yet thought explosion including during the baby boom, women were having less babies than ever before, and as the number keeps falling the boom is ending.

So, what caused the boom, why was there a population explosion even when birth rates were falling? Could our population grow until we are living life like battery hens, or birth-rates keep falling leading to population collapse?

Population & Immigration

Population & immigration: Conflict and deception.

Immigration is short-term symptom of a potential long-term problem of the challenges to targeting an ideal population. We live an overpopulated planet where many governments use immigration to boost what would be otherwise falling population numbers while blaming 'illegals' for the very real negative consequences for their citizens from the boost to the population. It can be argued that reaching sustainability would address the question of overpopulation, but what would it take to end the need for deception, resolve the conflict, and have everyone work towards the conditions experienced in the countries with highest levels of happiness?

Births Per Woman: Not quite what you would expect.

Commenced: August 12, 2019 Updated: May 23rd, 2024

2024 May 23 : Added the natural population growth calculator.

TLDR; The magic number is around 2.3, not the 2.0 you might expect, results in a stable population. This is an exploration of what 'births per woman' means, and how it is measured. Key to discussion about population is population growth, which is most commonly analysed from 'births per woman', which is also called 'fertility rate'. But what is 'births per woman'? Answer: not quite what you might expect, which means a small adjustment is required for interpreting births per woman when predicting population growth.

Ideal/optimum human population: How many people can, or should, each country, and the whole planet support?

Commenced: April 11, 2023 Updated: May 1st, 2024

2024 May 6th: Second edition, fully revised to hopefully improve clarity.

It seems like the human population has forever been growing, but any analysis makes it clear growth must stop eventually at some level. Perhaps consider that the wealthier each person, the less people the planet can support when answering the question of at what level should growth stop? Do we go for the maximum possible people just before everything collapses, even if average living standards could be far better with a smaller population? When caged hens are farmed for eggs, people advocate for a lower population to allow living free-range for a better existence, yet with people being farmed by multinationals, billionaires and politicians growing the human population to grow the economy, it seems that denser and denser housing and reduced resources per person for human workers is accepted. Most countries seem to agree that global population growth should end but and state that ends its own population growth faces economic disaster.

Paradox Resolved: Parents wanting best for children drives falling birth rates, not women’s education.

Commenced: March 6, 2021 Updated: April 6th, 2024

2024 April 6 : Added debunking myth humans coped with high population growth future "The Population Bomb" feared.

Surprisingly, humanity is at 'peak child' and looks to be heading to population stability. The population explosion may arguably have left us with an overpopulated planet, but the explosion is ending, due to 'births' per woman falling from over 6 prior to 1900, and to around 2.2 in 2022. Some Economists panic about that and fear humans 'leaving peak population' and correcting to a lower population, even though that could benefit most of us. When first analysing the population explosion, I found a paradox as popular explanations for the fall in birth-rates like the "education of women" and other coincidence theories simply don't fit all the data. No, the Taliban are not onto something, as the real best answer is that people are motivated to have the number of children to give those children the best life possible in environment and situation, which may require environmental security and reducing inequality to limit the economist nightmare of further falls in birthrates.

Peak Child: When, and what does it mean?

Commenced: May 25, 2016 Updated: February 26th, 2024

2024 Feb 26 : Update in progress.

Globally, peak child arrived just a few years after this was first published, although this global picture is not experience at every individual location. Data now clearly confirms that globally, the world has returned to 'peak child', ending of three centuries of a population explosion, and perhaps even millennia of more gradual growth prior to the explosion. Return to peak child means we could either return to the gradual growth levels of prior to the industrial revolution or become a mature species and exist in balance with nature and other living things. Perhaps even stop displacing other species?

Surprises from life expectancy, the ageing population and the path to immortality.

Commenced: May 17, 2022 Updated: February 10th, 2024

2024 Feb 10 th: Updated synopsis and added elderly mortality.

Why your own life expectancy is greater than the average, and the rise in life expectancy from the just 32 years at the start of 20th to now being over 70 years by the 21st century does not mean what most people think. What has changed is less about ever longer lifespans, and more about people living an increasing percentage of the same full lifespan. Despite the lower life expectancy during earlier times, most famous figures lived to around age 70 not only in 1900 but even 2,000 years ago and Ramesses the Great lived to 90 back over 3,000 years ago! Infants are rarely famous, and as it is the reduction of child mortality that has the biggest impact on life-expectancy, despite the ageing population you don't see as much difference when looking at how long adults live, but we may soon!

Population on a Finite World: A zero-sum game with no vacancies.

Commenced: July 21, 2021 Updated: November 19th, 2023

2023 November 19: 2nd Edition with clarified rules and "garden of Eden events" explained.

From childhood I had assumed human population was growing because the world was not yet fully populated and life was still expanding, but reality is most the recent "garden of Eden scenario" occurred over 500 million years ago, and since then the planet has been fully occupied with a total biosphere of life in fact gradually shrinking. It turns out that no species on Earth can keep increasing population without quicky on geological timescales reaching its population limit. How has the human population kept growing if we have long been at our limit? By raising our limit through accessorised evolution and in turn lowering the environmental limits of other species. We have been, by the same principle of evolution Darwin declared "survival of the fittest" that allows new species to arise and grow their populations, competition from humans has been partially or fully "evicting" other species from their environmental niches. While when there were less humans this had little impact, it has now reached a scale labelled the Anthropocene where, if the human population continues to evolve and grow, other species face decline or face extinction.

Why population growth even before the explosion?

Commenced: August 21, 2022 Updated: August 15th, 2022

2022 August 15: First published.

Throughout history, although no other species on Earth has experienced such long term overall population growth, even before the recent population explosion, the human population kept slowly growing. Yes, we recently had an unprecedented population explosion, driven by the near elimination of previously tragic rate of infant mortality, but against a background of more gradual long-term growth, many of us may have never even realised we just had a population explosion. But what drove that long-term population growth even before the explosion, and what will now happen as the explosion ends?

Peak Population: Well, until the next population explosion.

Commenced: October 12, 2021 Updated: February 12th, 2022

2022 February 12: Minor update

For the environment, our peak population will be a nightmare. This page explores alternatives for the future of population, and the possibility that the current peak population will be the last time there are ever this many humans on Earth.

One Finite Planet

Now also on YouTube

Topics and Subtopics.

Why population growth even before the explosion?

Environment sensitive reproduction rates: parents instinctively seek maximum opportunities for kids.

Population Explosion: How did we get to 8 billion people?

Population & immigration: Conflict and deception.

Births Per Woman: Not quite what you would expect.

Ideal/optimum human population: How many people can, or should, each country, and the whole planet support?

Paradox Resolved: Parents wanting best for children drives falling birth rates, not women’s education.

Peak Child: When, and what does it mean?

Surprises from life expectancy, the ageing population and the path to immortality.

Population on a Finite World: A zero-sum game with no vacancies.

Why population growth even before the explosion?

Peak Population: Well, until the next population explosion.