Leaving Peak Population: We May Never Return.

(DRAFT)

For the environment, 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.

  • Introduction and Recap.
    • The Fragile Starting Point.
      • Endless Climate Summits: And We Need Them.
      • Don’t Mention Population.
    • Recap: Understanding How We Got To This Many People.
  • The Possible Futures:
    • The UN projection: stability.
    • Futurist Views:
      • The Most Common ‘Sci-Fi’ Future, continued growth, and the elimination of nature.
      • Collapse: The Dystopian Alternative.
    • Descent To The Plateaux: Leaving The Population Peak
  • to be continued….

Introduction and Recap.

The Fragile Starting Point: Should A Climate Summit Mention Population?

Endless Climate Summits: Governments Are Feeling The Need To Respond.

Recent human advances have provided great benefits, but have also come at huge environmental cost.

Huge strides in reducing infant mortality came too quickly for birth rates to compensate, producing a huge population explosion. In parallel, other advances such as plastics, automobiles and refrigeration have compounded the problem by increasing the environmental footprint per person.

There is now worldwide majority consensus, that the environment, under the strains of supporting over 7 billion people living as they do currently, is extremely fragile. Logically, two steps are required:

  1. Change how we live.
  2. Manage population going forward.

It has taken a very long time to get the current level of agreement on step 1: that we need to change how we live. Despite the at time of writing upcoming Glasgow Climate conference being the 26th climate summit (hence ‘Cop26’) , there still not universal agreement on a plan.

But Don’t Mention Population.

Step 2, population, described by many as the elephant in the room, is a topic avoided at current conferences, despite the widespread acknowledgement that population itself poses an existential threat to the environment.

David Attenborough: October 2018.

The naturalist David Attenborough once said the creature he finds “most extraordinary” is a nine-month-old human baby. But now he believes the planet can’t sustain many more.

In an interview for BBC Newsnight, the 92-year-old British broadcaster said: “In the long run, population growth has to come to an end. There are some reasons for thinking that will happen almost inevitably.

“But it is very alarming at the rate we’re going, and although people will say, ‘In the long run, we are going to stabilize’, they’re going to stabilize – as far as I can see – at a rather higher level than the Earth can really accommodate.”

BBC Newsnight, via churchandstate.org.uk.

It is true that action on how we live is more urgent, but what happens with population cannot be ignored.

Recap: Understanding How We Got Here.

I have been on a journey to understand what has been happening with global population since 2013.

I continue to uncover new surprises as I came to grok the pieces of the puzzle. The two most recent, and critical pieces of the puzzle were:

  • “Full planet”: The realisation that there has been a similar total amount of life since life on land began, and therefore increases in one species population always means decrease in the population of other species.
  • “Normal Population”: That most advanced life controls it rate of reproduction to reproduce at the optimum time and optimum number to ensure survival, and not beyond that number.

These follow from the realisation that, given it only takes a few thousand years of exponential population growth for any creature have enough individuals to occupy every millimetre of the surface of the earth, and even humans have been here for hundreds of thousands of years, there has been enough time to grow the population from just two people and carpet the entire earth with humans, or any other organism, time after time after time.

If it was our nature to reproduce until we overpopulate the planet, then this would have happened long ago. The reality is humans, like other advanced animals have managed to maintain a ‘normal population’ that results in a sustainable existence. While reducing infant mortality was worth almost any cost, doing so triggered the recent and abnormal population explosion.

That population explosion is coming to an end, as indicated by a return to ‘peak child‘.

Ending the explosion is only part of the solution, as we are still overpopulated.

On one hand, normally unusual population booms in nature soon end, population return to normal population, and the environment recovers.

But we have never seen a global population boom like this before, and the trigger for the boom remains in place, even though humans seem to be adapting birth rates to match the new normal of almost all children surviving.

The Possible Futures:

The UN projection: stability.

There are many graphs plot population growth as asymptotically approaching zero, as if stable population is the lowest rate of reproduction possible.

With everyone alive today born during a population explosion, and their parents, grandparents, great grandparents, and great great grandparents only ever experiencing a population explosion, it is perhaps understandable that even stable population seems a foreign concept, despite thousands of years of history revealing that stable population is the normal reality.

Perhaps in this context, it makes sense that the UN, with all the politics of member states at play, is reluctant to predict any population reduction. There is a cost to population reduction, for leaders of government, for big business, and for the extremely wealthy. Although these groups are small in number, they make up for it in influence, and do need delicate handling.

The difference between UN projections, and those such as Deutsche Bank who are financially motivated with no real need to watch politics, can be seen in this data.

Note this data, is now 10 years old, and that the journalist felt that, despite the projections for the year now seen as critical, 2050, being almost identical, that the difference between projections was the difference between “out of control” population, and “no problem”. The difference in reality is the size of the problem beyond 2050.

Futurist Views:

The Most Common ‘Sci-Fi’ Future, continued population growth, and the elimination of nature.

With future fiction, a genre of science fiction, when a positive future is envisaged, the future Earth almost always has a population that has continued to increase, potentially well beyond the carrying capacity of the Earth, where the number of inhabitants makes experiencing nature simply not feasible given the number of humans who would want to experience nature at the same time. Imagine your favourite wilderness area. If you visit with your family it is wonderful, but if 1,000 other families want to visit at the same time, it is no longer wilderness.

Yet this future of a crowded Earth filled with humans who never get to experience nature is the most common science fiction view of a positive future.

Examples: Fifth Element, Total Recall,

Population Collapse: The Dystopian Alternative.

From H.G Wells “Time Machine”, through “Planet of the Apes” and “Logan’s Run”, and to “The Hunger Games” and “Divergent”, stories of a future where an inevitable apocalypse that dramatically reduces population in the future is a very common way to picture the future of humanity.

Descent To The Plateaux: Leaving The Population Peak.

Yet there is another possible future. Back in the section on the UN version of the future, I referenced a BBC article with projections and assessments of future population back in 2013.

In just those almost 10 years, “births per woman” numbers have fallen to 1.1 in several countries, which given the required rate for population stability is around 2.3, suggests that, not only have major organisations predicted a future when population moves naturally towards a sustainable number of humans, the predictions are being supported by reality.

Consider the following:

  • Fertility rates and sperm counts are falling worldwide, including in areas not linked to a toxic environment.
  • Family sizes continue to fall globally.
  • There are an increasing number of couples not desiring children at all.

Understanding my perspective on what is happening requires reading “normal population“, but there is significant supporting data.

Conclusion: To be continued….

I will update this page progressively over the coming week. There is quite a lot more to add, including the economic implications….

Normal Population: A rule of nature is broken right now.

This page explores how, despite all other complex organisms on earth reaching a ‘normal population’ level, humanity seems to continue population growth.

Introduction:

Normal Population in a nutshell.

The concept of a ‘Normal’ population is that the entire population of each species follows a similar growth pattern to an individual animal.

The normal growth pattern for an individual is for each individual to experience a growth phase, until reaching an adult size, and then to remain at approximately the same size from that time. Every individual animal is also a ‘colony of cells’, and continues making new cells for its entire life, but the population of cells reaches a point of stability at the end of the growth phase, and while new cells continue to be produced, for most of the individuals life there is a stable population of cells. From maturity the number of cells in the animal remains at a ‘normal’ population: cell population stability. New cells are always being produced, but once mature, this happens only fast enough to continue the stable population. The average cell in a human is around 7 years old, even if the human is 70 years old. The same ‘person’ even though almost all the cells are new. When there is damage, there can be more rapid grown, just as when we lose skin cells, but once the damage is repaired, cancer aside, cell reproduction goes back to just the rate required for population stability.

The population grows to ‘normal population’, and then cell production naturally drops to the level required to achieve population stability, just as cells populations do in an individual adult. If the population is temporality reduced, the population will recover and again stabilize.

The concept of normal population, is that the entire species can also be considered as a living organism that grows the population of individuals until maturity when ‘normal population’ is reached, and then there is population stability.

Real World Example: Humpback Whales.

As an example, consider humpback whales. The population of humpbacks in the south Atlantic ocean fell from an estimated 23,000 to 34,000 in 1830 to 440 by in the late 1950s, and has since recovered to an estimated 99% of their previous population. This is 5.7 doublings of population is less than 70 years, or one doubling every 12 years. Despite their ability to double the population once every 12 years, and having existed in the Earths oceans without any significant predators prior to whaling for well over 1 million years, which is enough time to double in population 83,000 times, their population stopped doubling after within 15 doublings even if there were only 2 whales 1 million years ago. Clearly there is a normal whale population, and as these whales have not decimated their plankton food source and there there an not whales continually dying of starvation, the ‘normal’ population is not a result of deaths of whales or running out of food. Some natural process results in an whales growing in population up to an optimum number, as also happens with elephants, lions, or any other animal.

Despite every animal on Earth having had more than enough time to overpopulation many times over, most animals reach a ‘natural’ population level, at which point they only reproduce at a level that results in a stable population.

The Population: “Missing Puzzle Piece”.

Researching the history of human population uncovers a puzzle, and normal population finally provides a solution to that puzzle.

I have been exploring the state of global population since 2014, as outlined in the my population journey. Initially motived by the passionate sound of alarm by David Suzuki, I soon had my first surprise on learning that rather than follow a path towards annihilation as highlighted by David Suzuki, population growth rates had fallen towards a level of population stability.

I then learnt that the recent population explosion was an aberration, and the human population over time is normally remarkably stable. In the words of the great medical researcher and statistician Hans Rosling:

People in the past never lived in ecological balance with nature, they died in ecological balance with nature. It was utterly tragic!

Hans Rosling (see video, 19m)

The puzzle emerged: how did people manage to be born in appropriated numbers to match deaths for that ecological balance.

Doing the maths, it becomes obvious that for any animal in nature, exponential growth is impossible, because the timescales are too long. Just 63 population doublings in population takes any species from 2 individuals, to 9,223,372,036,854,775,808 individuals, which for anything beyond microscopic life, would fully cover the surface of all land and oceans of the Earth.

On a planet billions of years old, every living thing has had more than enough time for way, way beyond 64 doublings, and no species exists in the numbers that would result from continual doubling in population at even a fraction of the rate that species can double in population. Clearly, exponential growth over any significant time is impossible, and all life has some mechanism for population stability.

Plants, and some other organisms are resource constrained, which makes overpopulation impossible for those organisms. But for a huge range of species, from the bacteria in David Suzuki’s petri dish, through to humanity, population growth beyond a sustainable level is not only possible, but inevitable without some mechanism limit reproduction to exist in “ecological balance with nature”.

The missing puzzle becomes: how is it possible that most organisms can exist in a state of population stability?

Growth Cycles In Nature: The Concept of ‘Normal Population’.

Observations of nature: Did Elephant or other wild animal populations keep growing before humans?

I existed my entire life until recently, assuming that reproduction just blindly produced offspring in some fixed ratio relative to the parents my entire live until stopping and considering the alternative.

If we look at the populations of animals such as elephants in areas where there was not habitat destruction of poaching by humans, all evidence is the populations are stable. This is the same from whales in the ocean pre-whaling, through to polar bears and penguins. Plants and animals have flourished in natural habitats without constant population growth, and give the length of time these organisms have existed, if there was population growth then every habitat would be overrun. The reality is we see that population growth is not ubiquitous in nature, and at least almost all species manage a stable population when the environment is stable. This suggests either all species are resource constrained, or that there are natural mechanisms that control population growth.

The Mechanism for ‘Normal Population’.

Observation suggests that most living things tune their rate of reproduction to produce a stable population level.

The proposal is that evolution has resulted in many living things having evolved the ability to regulated their population at a desired ‘normal’ level.

How could this work? In practice, achieving a stable population would requires a feedback mechanism, so that when the population is below the ‘normal’ level, reproductive rate increases, and when the population exceeds the ‘normal’ level, reproductive rate falls. So for this idea to be reality, there must be examples in nature of mechanisms to control growth rates.

The Human Body As A Model: Growth Stops at Maturity, unless repairs are needed.

Consider how an individual experiences growth. For the first few years, growth is rapid, and then during teenage years, we stop growing, and spend the entire rest of our lives without further growth. It is not as simple as we stop growing, because while it seems possible for brain cells to last our entire lives, even bone cells only last 20 years, many other cells only last days. Our bodies are a population of cells from a series of generations. Cell production is continuous, takes place at varying rates for different cell types, but once we are adults, manages to produce cells at just the right rate for a stable population.

Further, consider what happens with skin cells when the skin is damaged. New skin cells are produced at an accelerated rate. If the accelerated rate continued, there would be excess growth around the wound, but once the wound heals, the growth rate returns to normal.

Mechanisms of Population Control at the Cellular Level: Contact inhibition of proliferation.

Some mechanisms of population control at the cellular level are well known. Contact inhibition of proliferation, a clear and simple example of population control, is where the density of cells in a given region controls the speed at which cells reproduce, with signalling between cells playing a key role. Although we are still learning all the details of ‘contact inhibition’, including having learnt that actual contact is not required, it is clear that population density can directly inhibit population growth at a cellular level.

Just as too many organisms endangers the entire colony, too many cells also endangers the entire organism, and without a mechanism to stop cell reproduction, our bodies would have cancer like growths or actual cancers.

Contact inhibition of proliferation, that is, the phenomenon that cells stop proliferating upon contact formation has been described several decades ago (Fisher and Yeh, 1967), but the underlying mechanisms are only now emerging. Importantly, loss of contact inhibition is a hallmark of cancer.

Science Direct

As discussed in ‘life in the colonies‘, in fact we are all colonies of cells and what happens at a cellular level normally propagates even to the level of societies.

Mechanisms of Population Control in Animals: Kangaroos as an example.

Today in Australia the population of kangaroos is a problem for farmers, however it should be considered that, despite kangaroos in Australia having had 24 million years to grow their populatio , the Europeans did not arrive to a country overrun by kangaroos. While there are now more kangaroos than desired by farmers, that is partly as farmers raise not kangaroos, but sheep and cattle, and they all eat the same food.

In fact, the kangaroo population manages to reduce to a ‘drought normal’ in response to drought, and return to ‘non-drought normal’ when droughts end, without any assistance from humans.

Periods of extreme drought may delay the onset of maturity in female kangaroos and lead to suppression of their fertility cycles. At the same time most fertile females cease to breed. As a drought worsens, fewer and fewer females have joeys either at foot or in their pouches.

After two years of drought a population may include females aged three years or more which have never produced young, while none of the kangaroos in the area would be younger than two, the precise duration of the drought.

Australia’s Amazing Kangaroos and the Birth of Their Young

That droughts last several years in Australia allows kangaroos to provide a clear example of how large mammals can not only maintain a ‘normal’ population, but even adjust to a ‘different normal’, in this case for the duration of a drought, and then return to ‘regular normal’ when the drought ends:

Following rainfall and growth of new herbage, kangaroos come into breeding condition almost immediately. However, it can take as long as eight years for kangaroos, even though prolific breeders, to reach their pre-drought numbers again.

Australia’s Amazing Kangaroos and the Birth of Their Young

Alternatives to ‘Normal Population’: Predation and Resource Constraint.

Resource Constraint.

David Suzuki: Bacteria in a petri dish 2010.

It sounds simple, the number of organisms is limited by available resources. In fact, this simple model does appear to apply for some living organisms.

Recall the original “bacteria in a petri dish” by David Suzuki? This example highlights both that the bacteria do demonstrate resource constraint, and the limitations of relying on resource constraint for population control. Unless the constrained resources can be renewed from zero, like new sunlight each day, population will continue to increase exponentially until the constraint is reached, completely exhausting the resource. Then there will be the catastrophe of maximum population and zero resource. Relying on resource constraint for population control is often going to be a path to extinction.

Consequently, observation reveals most complex organisms have evolved population control that avoids the problems of relying on resource constraint. Even ignoring the fact that relying on resource constraint will completely devastate the critical resource, we simply do not see animals where the population is control mechanism is a significant number of deaths by starvation due to lack of resources. If population control was a result of only resource constraint work, there would always be too many lions in a safari park and a given percentage would always be dying of starvation, and when we went into a national park, we would see a percentage of dying starving animals. Further, the lions would continue to populate unsustainably devouring all their prey.

What we actually see is that, as with the kangaroos, animals seem to manage their reproduction to produce only the number of offspring that the resources will sustainably support.

Constraint by Predation.

One alternative to a species controlling its own population would be external control from predation. Certainly for many animals, a reduction in the number of predators will see population numbers increase, which suggests at least two possible explanations for this observation:

  1. The species is has no population control mechanism other than predation.
  2. The range of reproductive rates of the species has evolved to allow for predation.

The first explanation has three problems. Firstly, it is natural that the species would evolve before predators for their species exist, so they would have nothing to prevent catastrophic population growth prior to predators appearing. Secondly, while predation would slow growth, there is no way it would automatically result in a stable population, as any time the population of the species grows, survival rate from predation would increase, resulting in even more population growth, and a decline in population would result in a higher rate of predation leading to extinction. Thirdly, this mechanism breaks down with apex predators, for whom predation provides no population control, and so apex predators would continue population growth until the wipe out all of their prey.

The second explanation seems far more likely. That species do have another mechanism of population control that when combined with predation produces a stable result, but that other mechanisms may not be sufficient when predator numbers change dramatically.

Population Growth from a human Perspective.

Why Can’t We As Individuals Keep Growing?

Imagine a human growing up without any adults as a reference. Year after year this human gets larger. Why would this person assume that at a certain age they will stop growing? I can imagine it would be disturbing for such an individual, having experienced year after year of increased growth, to observe their growth decrease and eventually stop. In such a situation, would you wonder if you were dying? Or worry if something was wrong with you to stop you growing?

Or perhaps, this lone individual human would notice that it seems normal for other animals to reach a ‘normal’ size at maturity, and then exist at that same size for the rest of their life?

Don’t We Notice “Normal Populations” in Nature?

Or maybe the human wouldn’t learn from what happens with other animals. Humans have habit of assuming we are beyond the rest of nature, and can seem that we have not learnt about population growth from observing other animals. We don’t expect the populations of other living things to just keep growing, and we don’t expect their lack of population growth to be result of significant starvation, yet it is not common to consider what this means for humanity.

When I walk though a national park, I have never even though about the fact that the number of lizards in that park has remained basically the same for millions years, because I assumed that like us humans have lately, all animals must always increase in population. Of course when you think about it, clearly it is impossible for these species to have been increasing in number for millions of year, but I never thought about it.

But I had also not thought about the fact that when I enter a national park, there is no abundance of animals dead from starvation as a consequence animals having too many young. When there are fires or other disasters naturalists all talk of populations recovering, but as humans we don’t think about how these populations reach a ‘normal’ level and then remain at that level.

Somehow, we have animals all around us with ‘normal populations’, without it occurring to us to ask “do we have a normal population?”

Human Population: Continuous Growth, or ‘Normal Population’.

It Can Look like Resource Constrained Continuous Growth: But its not!

There is that David Suzuki model of population growth like bacteria in a petri dish, which looks a lot like t human population growth of 1960, or even 1980. Human population growth has been at 2% per year a rate of doubling every 34 years! Clearly unsustainable, unrestrained growth that will soon result in all resources being decimated!

But then, stepping back, doubling every 34 years would produce 64 doubling in just over 2,000 year, so we would expect at least 9,223,372,036,854,775,808 humans by now, even if there were only two humans just over 2,000 years ago! We should have at least 18,000 humans per square metre of the entire earth!

It turns out, through most of history, population growth was almost non-existent, and then we have a had a recent explosion.

This seems the exact opposite of what is expected. Instead of growth before reaching a ‘normal population’, humanity had a boost of growth long after reaching ‘normal population’.

Full Human Population History: The Reality Of Human Population Growth.

If we consider humans as a species that evolved around 300,000 years ago, we should have been able to reach our ‘normal’ population within at most 10,000 years.

Yet, although normally very gradual, there has been continued population growth. Discounting the recent population explosion since 1801 for the moment, to go from two humans as to around 1 billion humans in 1801 would be an annual growth rate of only 0.007% per annum. That is assuming continuous homogenous growth, which seems unlikely. But there is still a long term trend of very gradual growth, and that can’t happen with every species, or the world would be getting fuller and fuller, and it is not.

An increase in population of one species would normally occur following a step in evolution, and result a decline in the population of other species displaced by the new improved more evolved species. With humans, it is not the species that has continued to evolve, but the societies of people that have evolved.

Looking more closely, human societies have driven population increases due to changes:

  • Increased range due to migration.
  • Improved tools in the progression from Palaeolithic age to Neolithic age.
  • The invention of farming.
  • The rise of civilizations.
  • Continual introduction of of new technology.
  • Propagation of new technology societies.

So to put all of this together, the history of human population is linked to the evolution of not the human species, but instead evolution of human society. The pattern is that human populations:

  • Are completely static for most of human history.
  • Exhibit very slow growth are evolution of society increases range and slowly improves technologies.
  • Has seen bursts of growth following major society evolution such as the introduction of farming.
  • Saw unprecedented growth during the population explosion from around 1800 to year 2000.

Population And The Evolution of Human Societies.

Normal population should see a ‘normal population’ quickly achieved, followed by population stability until evolution results in a new species.

People have not really evolved, but society certainly has evolved. In many ways, rather than the species ‘homo sapiens’ being the organism, the organism is the society. Practices adopted by each society changes both the ability to compete with other species for resources, and ‘normal population’ that can be sustainably supported within a given environment. The entire basis of ‘normal population’ is that the control of population evolved to protect the organism that is the colony. Just as individuals stop growing at maturity, societies stop growing at maturity.

But when a society evolves into a new society, just as when an individual gives birth to offspring, the limitation of growth is reset, and the society grows to a new maturity, just as would an individual baby.

Professor Hans Rosling: Historically, deaths resulted in an ecological balance with births.

As the evolved society grows to a new ‘normal’ people can increase family sizes, lifting population levels. Still, in all the more recent human history where we have statistics, population levels were remarkably stable up until the recent population explosion. In fact, population levels have been so stable, that either it has just been an amazing coincidence, or humans also have some mechanism that has ensured births are in balance with deaths.

Historically, we can see over time the human population has grown at specific times, but the long term stability suggests long periods of population stability. As a ‘colony’ or society, there has been major evolution, sometimes gradually, and sometimes in great leaps. Population ‘normal’ does seem to increase incredibly gradually when society evolves gradually, and move ahead in leaps with breakthroughs to society like the introduction of farming.

Population Explosion: The Breaking of ‘Normal Population’.

An initial assessment could be that the industrial revolution must be an evolution of society that triggered a new, higher ‘normal population’ for human beings, so in response the population expanded. Improved farming techniques able to support a larger population, either reduced deaths from starvation, or triggered people to have more children.

Reality is, deaths from starvation were not reduced during the explosion, and instead, some countries experiencing a population boom, such as China and Bangladesh experienced famines, as a result of increased population. There is a link for the population boom causing starvation, and no link for a reduction in starvation causing a population boom.

Further, analysis of birth rates shows that birth rates declined during the population explosion. An increased ‘normal population’ effect, should trigger increased birth rates. Perhaps there rare locations where birth rates rose somewhat, but if so, this was more than offset by almost all of the world experiencing reduced birth rates.

All evidence is that that main driver for increased population, was the reduction of infant mortality. The goal in almost eliminating infant mortality, is the reduction of suffering, and the resulting population explosion was a side effect, not a motivation. This means that the previous balance of population was broken by improved an improved medical system, and that the population explosion was not humanity adjusting to a new level of ‘normal population’.

The End Of The Population Explosion: ‘Normal Population’ Resumed?

With infant mortality largely eradicated, far less children are required for births to be in balance with deaths. It does seem that birth rates are adjusting downward, to restore ‘normal population’, and generate birth rates that are again produce a population in balance.

What we have seen, is that when families needed 6.0 (six) children to maintain the population due mostly to infant mortality, families had 6.0 (six) children. Now, with infant mortality down to a level where only 2.3 children are required for a stable population, families globally are having only 2.3 children. Is this a new coincidence? Or is this evidence of a mechanism for ‘normal population’ in humans?

The Mechanisms Of Stability and ‘Normal Population’.

Mechanisms In Nature.

Kangaroos do not get together and debate “drought headed this way, we all should agree to hold off having children”. Instead, the reduction in offspring is the result of instincts. Many plants an animals reproduce either only, or predominantly in spring. Their biology could allow them to reproduce throughout the year, but they are ‘triggered’ to reproduce only when there is the greatest chance of survival of their offspring. Reproduction does not just happen all the time as with the bacteria, sophisticated animals and even plants reproduce in response to stimuli. It also logically follows that they reproduce not at the optimum time, but in the optimum number. Any animal that reproduces in numbers that would destroy the environment soon becomes extinct.

Are Humans Beyond Nature?

Are we humans really that much different? Isn’t our desire to have children also driven by instinct? Yes, following those instincts may lead to some of the greatest joys in life, but it still makes sense that these are instincts. Instincts that in just over 100 years have result in our joy being fulfilled by giving birth to far less children than in all of previous history.

I can see three possible factors altering the number of children people have:

  • The number of children people feel the instinct to want to have.
  • Sperm counts in males.
  • Conception rates in females.

What is the reason an increasing number of people choose to be child-free? Is the instinct to have children influenced by environment? Perhaps there is more to the global decline in male sperm rates than some people have considered. The most popular theory is the decline is due to chemicals in the environment, but I am not the first to consider it could at least in part be due to a natural response to being above ‘normal’ population?

When Mechanisms Fail: From ‘Normal Population’ to Plagues and Population Explosions.

Population stability results from a balance between births and deaths. Deaths are mostly determined by environment, with the species in question needing to adjust births to match deaths, over which the species itself normally has no control. Disease, predation, and natural disasters can all impact deaths, and as adjusting births takes time, there can be near extinction events or population explosions and plagues, but over time, populations return to normal, and the environment recovers.

Has the Human Explosion Exceeded ‘Normal Population’?

The Recent Population Explosion in Perspective.

To recap, humanity has just experienced the greatest population ever. The industrial revolution is often given credit for supporting this population explosion, but data clearly shows rather than a rise in birth rates in response to people being motivated to have more children, people had less children during the population explosion.

Perhaps the advances of the industrial revolution caused birth rates to fall more slowly as we adjusted to the ‘new normal’ of almost all children surviving, but the increase in population was all a result of birth rates not falling quickly enough to adjust to the new smaller number of children required. The medical advances were rapid, and resulted in saving lives of children already born that would have perished without these advances. It would be impossible for people to adjust the number of children they had in anticipation of medical advances.

Clearly, even if there was no basis for an increase in population, solving the problem of infant mortality would result in an huge lift in population whether desirable or not, as people adjust to the new ‘normal’ number of children.

Statistics on birth rates show we are again at ‘peak child’ and population stability has returned, but now we have an increased population, that, for the first time, was not increased by human birth rates in response to a readiness for a population increase.

Now we are faced with this hugely increased population, whether society is ready for it or not, and the result is that we are currently not able to exist sustainably. The definition of carrying capacity is the number of a species that can exist sustainably. Clearly, we are currently over carrying capacity, and thus we have overpopulation.

You would never trade sustainability for saving all those infants from death. Solving infant mortality was worth the price of resultant overpopulation. But now we are in a race to change our society so that the current population is sustainable, before the damage to the environment is too great.

The Environment Always Recovers From Plagues In Nature, So No Problem?

The human population explosion is unusual as humans it was largely a result of improvements in medicine, but nature also gets out of balance and can produce population explosions, and populations normalise, and the environment recovers. Every time. Locust plague, mouse plague, whatever, the population normalises, and the environment recovers.

On that basis, the human population should normalise to a level that ends the damage to the environment, and then the environment will recover. But there are two potential problems:

  • Humans are now a global society, so this is global population explosion, and the environmental damage is global.
  • Humanity is not ready to accept solving the problem with through population reduction, and in reality, in this case, population reduction alone is most likely not a viable solution anyway.

The reality is the problem of a global overpopulation of humans is complex, and there is already significant focus on solving some of the most pressing problems. However, further interference with nature to exacerbate the root cause of many environmental problems. overpopulation, is an ongoing risk.

Conclusion, and Where Next?

The evidence for ‘normal population’ is compelling, as is the evidence that humanity had a population explosion that breaks the rules of ‘normal population’.

The planet needs a solution to us having broken with ‘normal population’. We either need to find a way to bring or ‘normal population’ up in number to match the number of people we have, or just manage things hoping ‘normal population’ will see the number of humans naturally return to an appropriate population. Or perhaps, some combination of both.

What we do not need, is economic greed of the few who would benefit, driving a push for further population increases with a total disregard for nature.

My Journey To Understanding Population, and ‘normal’ population .

Population is a complex area. To arrive at my current point of understanding, it took me a number of light bulb moments over the years since 2013, with many realisations shattering some of my previous beliefs, and sometimes taking years to be ready to take the next step. This page is a recap of my journey, and if you can move quickly from step to step, then you can absorb information faster than I can, but perhaps this information will inspire others on their own journey.

This page is about a journey towards understanding population. The steps have been:

  1. David Suzuki and The Petri Dish: We are doomed!
  2. Growth is Slowing and ‘Births per Woman’ are falling: There is Hope?
  3. It is better than it looks: Hans Rosling, Peak Child, and The Population Pipeline.
  4. Not Normal: The Last 250 Years Of An Unprecedented Population Explosion.
  5. What Caused the Explosion? Could It Happen Again?
  6. What Ended The Explosion? The mystery of Falling Birth rates and the return to stability.
  7. Full Planet: Population increase always comes at a cost.
  8. Normal Population‘: The natural balance and mature population stability.

1. David Suzuki and The Petri Dish: We are doomed!

David Suzuki: 2010.

Watching David Suzuki, it becomes clear that while economists insist that perpetual exponential growth is essential for a thriving economy, perpetual exponential growth is impossible in the natural world.

This is step 1. The evidence of huge population growth continuing is overwhelming.

It is easy to believe that greed will lead to our downfall, and perhaps it will, but it turns outs, despite continuing population growth, the dire predictions of the 60s and 70s have not come true, because humans have dramatically reduced the rate of growth, avoiding the 13 billion we would have already if the peak rate continued.

While I posted my original concern about population growth in 2014, I had already been researching and a few months after that page, I came to realise that although principles describe by David Suzuki are relevant and important part of the journey, the picture is more complex and these principles are just a starting step.

Step 1 is: “exponential population growth is out of control, we are doomed”!

2. Growth is Slowing and ‘Births per Woman’ are falling: There is Hope?

By 2015, I had learnt that exponential growth was no longer the pattern playing out, as the exponent was decreasing.

Rather than continuing the accelerating exponential growth seen up to the 1960s and 1970s, and discussed by David Suzuki, the population growth rate was now slowing. Even such authorities as the UN projected population growth was now on trajectory towards a peak population, and that after that, population levels could even fall.

I posted “Population: Brace, the slow down has started!” in early 2015, and there were comments from people who strongly believed “this is wrong, we are all having too many children and will perish as a result”. Beliefs are powerful and it is hard to change beliefs in a short time by new information in response to new information.

Too many children? If so, then of course population would still be growing. What is “too many children”? The best measure available is ‘births per woman’, also referred to as fertility rate, and rather than 2.0 being zero growth, complexity of measurement and other factors mean that around 2.3 population stability.

Clearly, births per woman has been falling, but regardless of the predictions by the UN, the data so far still has the worlds population rising.

Growth ending is only a projection.

And population growth may appear to be slowing according to the UN data, but slowing, is not necessarily stopping.

Birth rates have fallen and are still falling, the rate of growth is slowing, and this slowing growth is already is a huge change. If even the rate of population growth is slowing, then our entire economic system which has evolved to be centred on significant population growth, is in for a severe shock.

But population growth slowing is not an end to population growth, and that is where step 2 leads.

Step 2 is: Population growth is slowing, but despite declining birth rates, population growth continues and it is hard to have faith population growth will ever be sufficiently constrained.

3. It is better than it looks: Hans Rosling, Peak Child, and Population Pipeline.

In fact, I reached step 3, even before I discovered the talks by Hans Rosling.

The realisation came that despite the population still rising, growth was indeed set to halt. We are still seeing a rise now, because there is a lag between birth rate changes, and what happens with population growth. It took me several explorations such as ‘brace‘ and ‘population lag‘ before being confident enough this was reality.

Now years later there are many more sources of this news, and by 2020 even the BBC was predicting a total population crash, even while the population is still growing.

However, watching Videos by Hans made it far easier to feel comfortable with this step, and his videos, including Ted Talks, and Gapminder videos, are recommended watching.

Professor Hans Rosling.

Hans explains birth rates have already fallen to the level that results in “peak child“, and that this will given time, result in the end of population growth.

This at first seems hard to believe, as you would think peak child should immediately result in “peak population“, but it turns out there is a delay due to the “population pipeline” which means that peak population is typically around half of life expectancy later than peak child.

Hans was somewhat of an optimist, with belief that although population levels are already a challenge, it is inevitable that having reached peak child population will stabilise and it will be manageable. But what about all the economists and politicians declaring we must have perpetual growth?

My own explorations

Step 3 is: An understanding that peak child arrives prior to peak population, and that population pipeline will mean changes to birth rates will take 30 to 50 years to fully be reflected in population growth. But there is still a nagging doubt something could result in population growth continuing.

4. Not Normal: The Last 250 Years Of Unprecedented Population Explosion.

It is natural to assume that the pattern of population growth seen by our parents, grand parents and great-grand parents has been as things have always been. But no, while ‘peak child’ and generations a similar size to that of their parents, is how things were for tens of thousands of year and all of history until the last few hundred years.

The growth from less than 1 billion people in 1801, to almost 8 billion people, a sixteen fold population increase, has happened in just close to 200 years. Homo-sapiens date back 300,000 years, and population growth from 2 homo-sapiens 300,000 years ago to 1 billion in 1801 would be an annual growth of below 0.007% and see the population double only once every 10,000 years. Not 100x faster growth of almost 7x more people in just 200 years which is 1.0% population growth every year!

Looking back at the UN data with the predictions above, it is quite clear that until around 250 years ago, population levels had been relatively stable for a long time. This rapid population growth, is specific to the last 250 years.

Why was population growth so much slower throughout history, even when people have had families with an average of well over 2 children per family. We have all heard of families of 10 or even 20 children, but of course there were also families with no children, but still the historical average has been 6 children per family.

Hans Rosling gives his answer to why there was population stablility prior to the ‘population explosion’:

Why did the worlds population grow so slowly before 1800? Throughout history, all historical records show that on average, 2 parents got more or less 6 children. But that looks, as a very fast population growth. So why didn’t it grow? Because 1.. 2.. 3.. 4.. of the the children died before growing up to be children themselves. People in the past never lived in ecological balance with nature, they died in ecological balance with nature. It was utterly tragic!

Hans Rosling:,historical families sizes allow for children dying.

Step 4 is: Understanding that population growth as seen in the 19th and 20th centuries is not only unsustainable, but also unprecedented.

5. What Caused the Explosion? Could It Happen Again?

Realising we have had one explosion raises the question, how can we be sure there won’t be another population explosion, unless we know what caused this last population explosion? If we had an explosion once, perhaps the same will happen again?

The Cause.

It turns out, that, as explained by Hans, the explosion was caused not by larger families, but by children surviving.

But with the industrial revolution, this changed. Better wages, more food, tapped water, better sanitation, soap, medical advances…. So from all these advances, why did population grow? Was it because they got more children? No! In 1963, when I was at school [the peak of population growth], actually the number of children per woman had decreased a little in the world, to 5. And the reason for the fast population growth was the improved children survival, 4 survived at that time. But still 1 out of 5 died, that was still terrible.

Hans Rosling: Children stopped dying due to improved health.

It is clear early in any analysis, that the population explosion between 1650 and 2000 represented exceptional, and from all records, unprecedented population growth. It was indeed a population explosion.

Again, what caused this period of exceptional population growth?

  • Increased family sizes.
  • Increased food production.
  • Reduced infant mortality.

Comparing family sizes before and during the explosion, children born per family was lower during the explosion than before the explosion. Food production may have enabled avoiding famines as a result of the population increase, but it was not more births, but slightly less births with greatly reduced infant mortality that triggered the increase. Prior to the explosion, while food was always great quality, population was not constrained by available food, and family sizes did not increase their number of children in response to more food, as clearly, families did increase the number of children being born.

Clearly the explosion was driven by the reduction in infant mortality, as explained in more detail here.

There is no question that reduced infant mortality triggered the explosion, and progressing to this step only requires reviewing the evidence and waiting for the answer to sink in.

Could It Happen Again?

We have very much solved infant mortality. There are still child deaths, but these are now in sufficiently low numbers that even eradicating all remaining deaths will have insignificant further impact on population. Therefore the exact same problem will not reoccur, however there medical advances that result in longer lives would increase the number of people alive at any one time. As the elderly do no currently reproduce, the impact is a one time increase, rather that ongoing population growth, however if these secret of living indefinitely is ever revealed, then we reach a whole new overpopulation problem.

Step 5 is: Understanding there was an explosion, and it was clearly driven by the reduction of infant mortalities.

6. What Ended The Explosion? Solving The mystery of Falling Birth rates.

Understanding that the population explosion was ended by falling birth rates raises a huge, and unanswered question:

What caused the fall in birth rates that brought an end the population explosion?

It is huge because without an answer, the future is dangerously unpredictable. It is unanswered, not because there is no answer, but because people are not agreed on a correct reason to be the answer.

Unlike a boom caused by a temporary increase in birth rates, a boom caused by increased child survival cannot happily end by having things return to how they were before. We do no wish to return to high infant mortality to end a population explosion. Falling birth rates is a better solution, but a puzzling one. Now we have two changes. Reduced infant mortality and reduced birth rates, but the reduced infant mortality was intentional, while for the most part, reduced birth-rates occurred without specific intent or even necessarily obvious reasons.

There are several suggested reasons including:

  • Family Planning programs and measures by governments to reduce population.
  • The availability of birth control.
  • The education and changing role of women in society.

I discuss each of these in Why are birth rates falling?

Generally, the answers have problems. Yes, some countries, notably China, took steps to reduce birth rates, but most countries took no steps, and still have falling birth-rates, so steps to reduce birth rates are at best a partial explanation relevant only in some cases.

The most commonly accepted explanation is that factors not planned to lower birth rates, and not directly linked to the population growth explosion, are central to returning population growth back to historically normal levels.

The other possibility would seem to be that the reproductive instincts of humans, like other animals, is a drive designed by evolution to produce a sustainable population. We seem to think there is some logic that makes humans decide to have a specific number of children, or to fall in love in the first place, and even to love our children. In reality, surely these are not logic, but things we have evolved to be driven to do. And if so, it would seem logical that we are driven to produce an appropriate number of children.

That such factors play a role is the only explanation for throughout history people having an appropriate number of children.

7. Full Planet: Population increase always comes at a cost.

We live in a society where the virtues of ‘growth’ are heavily promoted. We also live in a society that has just experienced a population explosion. All this combines to create an illusion of a world where growth is the normal, and population growth is the normal.

But if population growth is the normal, the in the past, the population of life on Earth must have been much smaller. The Earth should have spent most of its history almost barren of life, with the amount of life gradually increasing to the current level, and continually increasing from this point forward.

Yet, most of the story of the Earth does not match that story of growth.

Prior to around 400 million years ago the Earth did have basically no life on land, but that was because the lack of protection from radiation and lack of a breathable atmosphere made life on land impossible. It turns out that within a short time of life appearing on land, there was as much life on land as there is today.

For the past 300 million years, new living things have bloomed in population, but only by replacing previous living things.

Same with humans. We can keep increasing our numbers, but only by decreasing the number of other living things we sharing the planet.

8. Normal Population: We Evolved to Reach A Stable Population Plateaux.

The next step for me what a light bulb moment arising from thinking again about those historical levels of growth, that for so much of human history had to be close to stability. Then comparing this with what happens in nature.

Gorillas in the mist tells the story of a population of gorillas that appears to have been stable for thousands of generations. Yes species, including gorillas are capable of population growth that would over time result in incredible numbers, but instead seem to quickly reach a ‘population plateaux’ or stable level.

Just three children per family surviving to have their own family would result in population growth sufficient for a population doubling every 50 years. Clearly while this has happened during the last 200 years, historically humans rarely average 3 children living to have their own families, because if just this rate continued for just 3,000 years of the 300,000 years humans have existed, we would have 9,223,372,036,854,775,808 humans, which is over 18,000 humans for every square metre of the surface of the Earth.

On a finite planet that is even 500,000 years old, every species on the planet has had sufficient time to completely overrun the planet. This means every species has way more time than need to reach it resource constraints, and for those that can exceed sustainable constraints, to exceed constraints and reach a catastrophic level of overpopulation.

If it was human nature to populate ourselves out of existence, you would think we would have already done so by now. Since almost all animals can exceed sustainable constraints and exterminate their food sources, there has to be a way animals naturally limit reproduction.

Conclusion and Where Next.

In a reversal of the situation back in 2015 when people questioned that population growth would end, we now have stories like this one from the BBC:

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.

Fertility rate: ‘Jaw-dropping’ global crash in children being born, BBC 15 July 2020

There are many predictions of population numbers up to 2100, when China, Italy, and Japan will all halve in population and Nigeria will have more people than China. The risk with these projections is do they project based on current trends, or do they predict future trends? The data seems to be the former.

What will happen next? If the ‘normal population’ concept is correct, then while the population may fall for a time, it will only continue to fall if that is what appears the right solution for humanity. I guess the next step is to explore just would the right solution for humanity be.

Population on a Finite World: No Vacancy.

Every niche on Earth where live is possible is fully populated to maximum capacity, and has been that way since within less than 100,000 years after life was first possible. Since then, ‘moving in’ has meant displacing the current inhabitants, in process Darwin declared “survival of the fittest”.

Is it easy to overlook that environments not fully occupied by “us” are always already fully occupied by “others”.

This is an exploration of how all environments becomes fully populated, how humanity has our current population and what we have needed to displace to get this far, and need to display to continue to displace to continue population growth.

  • Rules of Population Constraints on our finite planet.
    1. 100 doublings of population is beyond the maximum possible on Earth.
    2. If even 60 doublings were possible, even pandas or humans, could from 2 individuals within 3,000 years produce a population that would completely cover the surface of the Earth.
    3. Every living organism has had more than ample time for 100 doublings, and is normally population constrained by the limitations of a finite environment.
    4. Every niche for life, is full to capacity, except following catastrophes or major disruptions.
    5. Population growth of any species, requires environmental changes, or evolution enabling the ‘invasion’ of environment previously populated by of other species .
    6. Continued Population growth is only possible through continued reduction in populations of other species.
    7. Every species must find population stability at some point while limited to one finite planet.
  • What about humans? Are We exempt from the rules?
    • Human Population Growth, how does it continue?
    • Alternating Times of Stability and Times of Population Growth Through Technical Evolution.
    • Ignorant Displacement: Those displaced go unseen.
    • History of human population: growth steps through colonisation.

Rules of Population Constraints on our finite planet

Rule 1: 100 doublings of population is beyond the maximum possible on Earth.

One million is 1,000 times 1,000. Which means that an organism which could double once in population every 1,000 years, can double 1,000 times in a million years. Humans can clearly double in population not only within 1,000 years, but as proven in the 20th century, can double population in significantly less that 100 years. Yet, doubling population even 100 times is more than enough for any species to totally overrun the Earth. So what have humans been doing all this time? How come it took humans so long to reach 1 billion? In fact, why is the Earth not just totally overrun?

Lets rewind and check these numbers.

The ‘wheat and chessboard problem‘ illustrates how large numbers grow by repeated doubling, also known as exponential growth.

The wheat and chessboard considers doubling 63 times, in 63 steps from step 1 to step 64, doubling each step. One grain of wheat on the first square (20=1)as the starting value, leads to 2 grains on the 2nd square (21=2), 4 on the 3rd (22=4), 8 on the 4th (23=8), all the way to 9,223,372,036,854,775,808 on the 64th and last square (263). So a single living organism would result in 9,223,372,036,854,775,808 organisms after 63 doublings.

Given the total land and ocean surface area of the Earth 510,064,472 km2, and each square kilometre is 1 million square meters, the 63 steps results in 18,082 organisms per square metre of the entire surface of the Earth, which for those who do not speak metric, is over 180,000 organisms per square foot.

So starting from two humans, 62 doublings would result in 18,000 humans for every square metre of the Earth.

Not very comfortable for humans, but possible for something very small or perhaps microscopic. Allowing the 100 doubling steps would generate 2,485,275,234,437,872 organisms per square metre ( over 25 quadrillion per square foot) or 2,485,275,234 organisms per square millimetre of the entire surface of the Earth.

So 100 doublings would overrun the earth even with microscopic animals:

  • 2.5 billion organisms for every square millimetre of the entire surface of the Earth, as a result of doubling 100 times.
  • …or
  • So 25 quadrillion organisms for every square foot of the entire surface of the Earth, as a result of doubling 100 times.

For larger animals such as humans, even filling the ‘chessboard’ is not required, as just 60 doublings would mean over 1,000 individuals per square metre of the entire land and ocean surface.

Rule 2: 100 doublings need not take very long, even for humans.

Relative to length of time life has existed on Earth, 100 doublings of even slow population grown animals does not add up to very long time, relative to planet over 4 billion years old.

Every organism must have a mechanism to multiply, or they could never have reached their current population level, or recover population level in the event of catastrophe or disruption. Past population growth can be used to calculate a population doubling time. For example, pandas have been shown to be able to increase population 17% in a decade. A 17% increase means 117 pandas for every 100 after 10 years. Since 1.17 to the power 4.5 is greater than 2, then pandas at that rate would double in population in 4.5 decades, which is a similar to the population growth rate to humans between 1923 and 1972.

The population growth rate for humans makes sense. If every couple has 5 children, which is below the historic average prior to the 20th century, and if 4 of those 5 children live to have their own children, then humans would double in population every generation, or a doubling approximately every 30 years. Just one child above replacement rate would result in a doubling every 50 years.

But a but a doubling in population every 50 years would result in 60 doublings in just 3,000 years producing more than 1,000 individuals for every square metre of the earth, which with animals the size of either pandas or homo sapiens, would more than completely cover the surface.

For perspective, humans doubling at this rate, would have resulted in 100 doublings during the time of Ancient Egypt (over 5,000 years with almost 30 centuries as the leading civilization).

The takeaway is that every living organism, even us recently evolved homo sapiens, have had far more than enough time to double in population 100 times, and overrun the earth as a result.

Rule 3: Every living organism has had more than ample time for 100 doublings, and is normally population constrained by the limitations of a finite environment.

Every organism on Earth has had far more than sufficient time for 100 doublings of it population, but no organism has reached the incredible population number that would result if they kept doubling unconstrained.

Since, in a small time relative to how long species survive, exponential population growth can exceed the limits of the size of our finite environment on Earth, for almost the entire existence of any species, the population of the species will be at the limit possible given environmental constraints.

This means every organism has normally reached constraints that limit further population growth.

Rule 4: Excepting for shortly after catastrophes or major disruptions, every environmental niche is fully populated.

The times an organism would experience unconstrained or less constrained population growth are:

  • When a species first evolves, first reaches a new suitable environment, or evolves new traits overcoming prior constraints.
  • Following a major catastrophe or disruption that reduced the population below previous levels.
  • In the event of changes to the environment that alter constraints such as weather or climate events, or disruption of predators or competitors for resources.

As all similar environments are not necessarily connected, an organism can be new to an environment despite having existed for some time in similar environments.

When population changes are observed other a for a new species or species new to the environment, or following catastrophes or other major disruptions, the population change is as a result of changes to the constraints.

Changes to population constraints can be short term, such as weather events, long term such as ice ages and long term climate events, or the result of evolution as observed by Darwin, or evolution of technology such as stone tools, or farming.

Rule 5: Population growth of any species, requires environmental change or evolution enabling the ‘invasion’ of environment previously populated by of other species.

If every environment is fully populated, then the only way to increase population is to outcompete other species, or for the environment to expand.

Outcompeting other species requires some form of evolution, either of genetics or behaviours.

The first land plants and animals appeared about 400 million years ago, when land first became inhabitable due to the atmosphere finally having enough oxygen to block harmful radiation and provide for respiration.

Since that time, the land joined the oceans in seeing a succession of life has replaced previous forms of life, with each species that dominated a niche reaching, and then remaining at the capacity of that niche, before eventually being replaced by an improved species.

Rule 6: Continued Population growth is only possible through continued reduction in populations of other species.

The logical consequent of these rules is that growth beyond original constraints can only continue while a species can continue to partially or fully substitute for other species within their environmental niches.

Rule 7: Every species must find population stability at some point while limited to one finite planet.

Continuing to replace other species has a limit. Eventually there would be only one species.

Some species are automatically resource constrained from overpopulation. I suspect this applies to all plants, as a major resource, sunlight, cannot be ‘overconsumed’. However even a population of butterflies can reach a population level where their caterpillars consume all food in their environment, and as their food needs time to grow, this would leave no food for the next generation.

All organisms need to ensure they live sustainably, and for any organism that relies on existence of sufficient numbers of other organisms for food or coexistence, this means some mechanism to ensure they do not out compete the very organisms they rely upon.

What about humans? Are We exempt from these rules?

Human Population Growth, is it still in unconstrained growth?

It could appear that human population is still growing long after we should have reached our constraints.

With the pat t of humans can appear to have broken these rules. The theory says we humans should have reached a stable population close to 300,000 years ago, at which point population growth would stop unless humans continued to evolved to become ‘fitter’ for existing or new environments.

Yet human population growth still continues as was doubling every generation as recently as between in 1965-1972, and doubling every 50 years for half of the 20th century.

This would seem to suggest humans have never reached their limit, and our population is still growing unconstrained.

But further exploration reveals this recent growth follows pervious periods of population constraints. Homo Sapiens have existed for at least 300,000 years, which is sufficient for 6,000 doublings of population, yet if there were only 2 people 300,000 years ago, the population growth to 8 people billion now represents just 32 doublings in over 300,000 years. That would be a doubling at an average rate of less than once every 9,000 years.

To take 9,000 years to double the population requires an annual growth rate of around 0.008%. A rate so close to zero growth, that is far more likely the growth has mostly effectively zero, with occasional periods of real growth.

This means, most of the time, even the human population has had zero growth as been at a constrained level. But then, sometimes even populations that have reached a previous plateaux, experience additional growth.

In fact, looking at the history of human population growth, as far back as back as we have any data, we have never before seen population growth anywhere near the level that was seen in the 20th century.

But even excluding the recent population explosion, human population growth has extended far longer than the rules suggest, unless their has been an expansion of the environment, or evolution in some form.

Alternating Times of Stability and Times of Population Growth Through Technical Evolution.

Instead of a recent series of steps of biological evolution, humans have experienced technical evolution.

A list of some notable steps includes:

Note that even during periods of population stability, from 10,000BCE to 5,000BCE and from 200 BCE to 1600AD, there was still some population growth as humans managed to colonise more locations.

Ignorant Displacement: As Population Grows, The Displaced Go Unnoticed.

Our current society has evolved the technology to be ‘the fittest’ in almost any niches, that we can maintain a higher human population than ever before. We can also, per unit land, maintain a higher population of crops and livestock to feed us than ever before.

The downside is a history of not even seeing organisms displaced population increases are introduced.

In fact, historically even other humans displaced by humans have been repeatedly overlooked and/or underestimated. Despite that experts now believe between 10 and 16 million people lived above the Rio Grande in North America prior to Europeans arriving:

Few contemporaries agreed with Catlin’s lofty estimate [16 million] of the Indian population before contact with the white man. “Twaddle about imaginary millions,” scoffed one Smithsonian expert, reflecting the prevailing view that Indians were too incompetent to have ever reached large numbers. Alexis de Tocqueville’s cheery assertion that America before Columbus was an “empty continent… awaiting its inhabitants” was endorsed by no less than the U.S. Census Bureau, which in 1894 warned against accepting Indian “legends” as facts. “Investigation shows,” the bureau said, “that the aboriginal population within the present United States at the beginning of the Columbian period could not have exceeded much over 500,000.”

How Many People Were Here Before Columbus?

Even if there were only 500,000 people before Columbus, the nature of exponential population growth tell us, that as people had been in North America for around 30,000 years, the continent would have been populated up to the level of environmental constraints. Any land mass with even 3,000 years occupation will reach the maximum population possible for that society. Yet to people from Europe, America was ‘an empty continent’. Not only did the new arrivals not understand or see that the continent would be fully populated with the current population, they even failed to recognise the size of that population.

The new arrivals failed to recognise that this ‘new world’ continent was fully populated, and that their arrival must displace those living there already. In the 30,000 years since people first arrived in America, culture in free trading European/Middle Eastern/Asian society had managed to evolve 1,000 or perhaps even 2,000 years further in terms of dominating more of the environment, increasing population density and as a result displacing other organisms. The population of many species would need to decline in order to accommodate the influence of European/Middle Eastern/Asian evolution of society.

The spread to new territory and the impact on life before that spread highlights the changes humans had over time to the environment of Europe/Middle East/Asia, displacing other species as advances made humans the most ‘fit’ for ever more niches within the environment.

Delusions Shattered And Questions Raised.

Overview.

Calculating these numbers, has shattered some illusions I had previously been misled by, but has also raised some interesting questions still to be answered.

  • Shattered Delusions:
    • Both North America and Australia were fully populated prior to the arrival of Europeans.
    • I had thought population levels have been growing because the Earth had never been populated to capacity.
      • The reality is, Earth has been populated to capacity for the hundreds of thousands of years. Population increases result from changes to society that allow humans and their food to displace other species of life on Earth.
      • The question that arises is, has the recent unprecedented population explosion stayed within the bounds of the population now supported by our changed society, or has the change to infant mortality created an ‘overshoot’ resulting in overpopulation and the environmental damage that follows.
  • Questions:
    • As already covered, has the population explosion resulted in overshoot?
    • What does natural population constraint look like?

What is the process constraining natural population?

Consider our close relatives in the wild, chimpanzees, bonobos and even gorillas. To our knowledge, none of these animals was experiencing significant population growth prior to recent population decline due to habit loss. What stopped their population expanding, given that, like all species, their birth rates can achieve population growth where the population is lower than the constraint limit? There seems no evidence that starvation is the mechanism of population control, as we do not see a percentage of chimpanzees, bonobos or gorillas starving. If starvation was the mechanism of population control it would be everywhere throughout nature.

This topic to be further explored.

Conclusion: If it isn’t already, one day the ‘farm’ will be overcrowded.

Long before the first human walked the Earth, there was already ‘no vacancy’. For humanity to even exist, we had to outcompete and displace other living things. But is it our mission to replace every living thing possible until it is just us and the food we farm?

If our mission is to perpetually deliver economic growth as opposed to wealth per person, then yes, continual population growth is the simplest path to that mission.

However it may be that at some point, it feels like humanity is being ‘farmed’ to generate wealth for a small subset of people, at some point our farm will start to feel crowded to the point of existing like battery hens, rather than having our free range.

Coffee: How many cups a day is ok, or even beneficial?

There is conventional wisdom: too many cups of coffee can be bad for you. There are also, a surprising number of of extremely rigorous reports confirming a certain number of cups of coffee per day may be a good thing.

What is most often missing is the definition of ‘a cup’. How big is ‘a cup’ and what type of coffee? Given that long ago I learnt that the amount of caffeine in a ‘cup of coffee’ can vary by over a factor of 10x. When assessing advice on how many cups are good or bad, it becomes importance to be able to compare the type of cup of coffee you drink with the advice.

Continue reading “Coffee: How many cups a day is ok, or even beneficial?”

Natural Climate Change: Surprises From Nature!

There is a lot of focus on climate change caused by humans, as there should be! But this focus can miss just how fragile the environment is even with us breaking things. Some of the surprises are in store when we examine climate change in nature.

It turns out that drastic changes reducing the Earths ‘carrying capacity’, making the Earth less habitable, or even completely inhabitable, are all inevitable because of nature. Us screwing things up just hurries the process.

Here are some surprises from nature:

Continue reading “Natural Climate Change: Surprises From Nature!”

Australia: Per Capita Recession?

It was recently claimed by the opposition party in Australia, that Australia is now in ‘Per Capita Recession‘. A response from the Prime Minister stated that there was no such recognised economic term, implying that the figures underpinning a ‘Per Capita Recession’ are of no real consequence. A recession is two quarters of negative GDP growth, but implication is that the current two quarters of negative per capita GDP growth are inconsequential. So what does it all really mean, and does any of it really matter?

  • Per Capita Recession: A real thing?
  • Per Capita Recession Significant?
    • The stock market ‘big end of town’ perspective
    • The average citizen perspective
  • What has changed?
    • USA
    • Other Developed Countries
    • Australia
    • The impact: Separate Recessions.
  • Political Gift:
    • If the big end of town is doing well, then who cares about the average citizen!
    • An ignored target: Why?
      • influential interests
      • the fear of an immigration backlash
  • Conclusion: Per Capita Recession=A Real and Serious Problem

Per Capita Recession: A real Thing?

A search on google by me for ‘recession’ returned an entry from Investopedia as the first result. Just a few lines in, the following text is provided:

The technical definition of a recession is two consecutive quarters of negative economic growth as measured by a country’s gross domestic product (GDP)

https://www.investopedia.com/terms/r/recession.asp

Per capita GDP is not mentioned on that page. However if you search for GDP, the Wikipedia page reveals


GDP per capita is often used as an indicator of living standard

https://study.com/academy/lesson/how-real-gdp-per-capita-affects-the-standard-of-living.html

While there are imperfections with the use of GDP per capita to measure living standards, clearly, GDP per capita is a measure of living standard, while GDP is not at all a measure of living standard. This is why a country such as Sweden has a lower GDP than Mexico, but a far higher GDP per capita than Mexico. Why is the definition of recession based on GDP, when it is GDP per capita that measures living standards? Answer: Because Recession is more a measure for stock market performance, while the trend of GDP per capita would more directly measure the standard of living of the people. This is is why the term ‘recession’ is described on Investopedia. Further, historically per capita recessions have been a consequence of a drop in overall GDP. Recession per capita while GDP rises is a new thing, I would suggest as a consequence of an economy reaching ‘finite world‘.

So No: It is not a term historically as well recognised as ‘recession’ … but if it is new, of course it is not as recognised. The important question becomes: is it significant?

Per Capita Recession Significant?: The stock market perspective.

Consider the four major Australian banks, which each control around roughly 1/4 of the banking market in Australia. As, between these banks they control the entire national market, then with no innovation require by the bans, revenue from transactions for all the banks would grow by 10% if on average Australians increased spending by 10%. However, if spending by the average Australian remains static, but broadly across all layers of society the population increases by 10%, then banks would all record the same revenue rise. It makes no difference to the banks if the increased transaction values arise from more spending power per individual, or arise from an increase in the individuals. In either case the share value should rise. Either increase population or increase individual wealth… in either case their is economic growth which, to the share market dominated by organisations with a market share across the entire nation, will deliver growth in either case. To the financial community, to large national companies and their upper management, and to governments with a national taxation revenue and the politicians who are paid from taxation revenues, per capita GDP can be seen as irrelevant.


Per Capita Recession Significant?: The citizen perspective

Obviously, if per capita GDP is in decline, on average people are seeing their living standard decline. That is clearly negative. Any suggestion that the problem is not serious, is based on the assumption that either

  • a) the decline must be small or it would also reflect as a ‘real’ recession also hitting ‘the big end of town’,
  • or b) since the ‘big end of town’ is not in recession, ‘trickle down economics’ will ensure encomic benefits for all will soon return.

Assumption a) can be demonstrated to invalid. If the ‘big end of town’, corporations and upper management are still seeing economic growth, then individuals who derive income from these shares or being part of in this group must see their per capita wealth increasing. But the average over all groups is a decline in per capita wealth, despite the lift provided by ‘the big end of town’. This means the drop in living standard by those not included in ‘the big end of town’ must, collectively, be larger than the rise in living standard for those included in ‘the big end of town’. In fact, the further from recession ‘the big end of town’ is placed, the more wealth flowing to that group, the worse it must be for everyone else if, on average, GDP per capita is in decline while overall GDP is not in decline. It follows that the more diverse these two figures, the worse the situation for the average citizen relative to overall GDP. A per capita recession outside a regular recession, in an indicator of an increase between rich and poor with most people getting poorer. A serious social problem.

Assumption b) is also clearly invalid. For average wealth to drop, while one group is seeing a rise in wealth, there is a group seeing a rise, and a group seeing a fall in wealth. The group seeing a rise is the group quoted as the source of wealth in ‘trickle down economics’, but clearly some wealth is being transfer from the rest of society to this very group. In other words, what is being seen is ‘trickle up economics’ or trickle down economics running in reverse. So it is absurd to suggest trickle down economics will address the problem when in fact demonstrably the process is running in reverse.

A per capita GDP recession is now a red flag for a serious decline in household income, or effectively, a recession for most people in society. Many countries now have serious concerns about average household income even when GDP per capita is growing. If GDP per capita is falling, the problem is significant.

What has Changed?

Change of GDP has stopped being a valid predictor of household wealth. The result is a change to the concept of a recession.

USA

Graphs like this from the USA are frequently shown to highlight the problem:

https://economistsview.typepad.com/economistsview/2008/09/gdp-per-capita.html

There are various graphs to be found on the net, all of which show that in the USA, growth in even GDP per capita stopped being reflected in household income from around 1980. Sources blame ‘Reganomics‘, the disconnect between labour and wealth generation flowing from technology, and finite world. All probably contribute.

Other Countries

Here are two graphs from this article about the situation in the UK.

These two graphs also show the same type of divergence between economic growth and wages happend in the UK as in US, with only the timing delayed. While this is a limited sample, it does demonstrate the problem is not a US specific problem. In fact, a longer search and more graphs would show the same problem in developed economies globally.

Australia

Australia has been running the highest rate of immigration per capita of developed economies, leading to the highest population growth of developed economies.- the biggest change in the denominator or per capita figures. This provides the greatest gap between the GDP trend, and a GDP per capita trend. Australia has the same problems as the rest of the developed economies, however, has the greatest ability with the relative population growth, to have a rise in GDP even when GDP per capita is week.

The Impact: Separate Recessions

Previous large scale recessions generally occurred before the separation of the graph lines of GDP growth and per household growth. This means during previous recessions, the ‘big end of town’ and the ‘average citizen’ experienced the same recession. The big end of town being in recession means high unemployment, so previous recessions had high unemployment. The decoupling of GDP and household income means the average citizen can now experience a recession even without high unemployment.


Political Gift?

Translation: “If the big end of town is doing well, then who cares about the average citizen!”

The dismissal of the significance of a GDP recession by the Prime Minister of Australia (Scott Morrison) is in effect a statement that all that matters is ‘the big end of town’, and a statement that a decline in living standard for the average citizen is inconsequential. In fact, the Prime Minister has also stated the elections with be a contest between “enterprise and envy“. Combining that position with the stance on a per capita recession could be seen to be positioning the ‘national enterprises, upper management and large scale shareholders’ as ‘enterprise’, and everyone else as ‘envy’. While the argument could be put, that the elite minority who escape a capita recession by growing their wealth in reverse of the national trend are those government should govern for because they are the source of trickle down economics, on the other side it could be argued this is governing only for those with great influence and ability to donate to political parties. The fact that the Prime Minister, being in upper management in national organisation (the national government) is part of the elite group he identified as ‘enterprise’ when corelating the position on a per capita recession and a contest between enterprise and envy, should create a large target for the opposition.

A Target Ignored: Why?

While it was the opposition party in Australia drew attentaion to the per capita recession, there has been no follow through. It would seem that the response from the Prime Minister was tantamount to drawing a target on himself, but nothing has been fired at that target.

It would seem the government left an opening to be seen as prioritising ‘government for the economic elite’. With the “enterprise and envy” in place, then suggesting a per capita recession is of no consequence would could easily be seen as stating the majority of the country is in the ‘envy’ group, only the very wealthy in the enterprise group. So why no follow up by the opposition?

Vested Interests?

Could it be that targeting the government for governing for the benefit of the wealthy and influential is risking upsetting that group… and the opposition also is part of that same group?

Immigration Backlash?

To suggest that using immigration to ensure positive GDP results in the face of recession for the average citizen, is to question the current ‘immigration to drive economic outcomes’. The whole debate shows that immigration for economic outcomes actually only delivers a positive outcome for the very wealthy, while at the same time eroding the ethical value of immigration. Clearly the opposition is not ready to suggest “immigration for humanitarian outcomes”, which would again distance those very wealthy sections of society.

Conclusion: Per Capita Recession=A Real and Serious Problem

The main problem is that while it seems the opposition get the seriousness of the decline of wealth for the average person and the growing gap between rich and poor… the truth is that either they do not get the issues or are also more concerned about placating those very wealthy large national organisations and their managers and shareholders than they are about the interests of the average citizen.

Climate change: anthropogenic climate change is not 100% certain, just highly likely. How likely is our is our ability to stop it?

It can seem like the word is divided between those who will who will not accept any evidence of anthropogenic climate change, and those who will not will not listen any questioning of the need for action to prevent climate change.

Reality is neither group is correct because no case is 100% certain.  Even the official statements from the IPCC do not declare 100% certainty on C02 output driving climate change. The world is actually grey – not black or white.  The real key is dealing with probability rather than certainty.

Most of us will insure our home without needing 100% certainty that our home will burn down. We do not use lack of 100% as a valid argument for inaction with our home, so why advocate lack of 100% certainty as an argument for inaction on the entire planet?  The risk certainly justifies taking out insurance!  The real uncertainty worthy of  attention is “what if actions to prevent climate change will be ineffective or are insufficient?”  Typical of insurance, what if the ‘policy’ will not payout to cover the risk?

I heard a statement from a prominent “anti climate change” advocate: “Climate change is natural, it is happening all the time”.

The person making the argument was not known for great logic, but just consider for a moment, what if there is valid point?  Climate change can occur even without the meddling of humans. What if the current changes would continue even without further human This raises the possibility that, even if accepting that humans are a source of climate change, there may also be natural underlying change in combination. Or perhaps, human induced climate change has or will trigger additional natural climate change that may continue even if human behaviour changes.

How certain to you need to be that your house will burn down to take out insurance?  When the risk is high take out the insurance.  Anthropogenic induced climate change may not be certain, but it is clearly at a risk level where we need to take out our insurance.  Now consider, do we also need insurance that current steps will not prevent climate change as well?

Consider some background: Ice Ages.

Technically we are currently an interglacial period within Ice Age.  Ice ages have interglacial periods (like now) and glacial periods like in the move ‘Ice Age’.  You could call a glacial period a ‘very ice age’ and what is thought of in the popular vernacular as an ice age, but in fact the presence of even polar ice caps like we currently have qualifies as an ice age.  Over the past 100 million years the earth has spent more time outside ice ages (no polar caps at all) , than within ice ages (either polar caps like the present or glacial periods).  No ice age at all means way higher sea levels (as much 200 meters higher), and a glacial period results in lower sea levels (as much as 130 meters lower).

Over the past 3 million years (the entire time humans have existed) the Earth has alternated between the glacial and non glacial periods of an Ice Age.  The last time the Earth was truly outside an Ice Age was before humans existed, which may be why glacial periods also get called ‘Ice Ages’. Humans have not existed in a time ‘less Ice Age’ than things are at present.  However, the normal state of the Earth of the past 100 million years is to be outside an Ice Age… something humans have never experienced.  Within an Ice Age (as we technically are) the most common state is a glacial period, but we have had around 11,000 years in the current interglacial period.   Human civilization has really only existed in a inter-glacial period.  The least common state, of the least common state of the climate of the Earth.

Humans have live through the change from glacial to interglacial, but not civilization, and very specifically not a global civilization supporting over 7 billion people.  We have a very fragile system that is unlikely to support anywhere near our current population in a change to either a glacial period (never experienced by civilization) or the most common state of the Earth, completely devoid of polar ice caps, which has never been experienced by humans at all.

Now consider, are we really confident we can stop climate change?  Yes it is urgent that we do what ever we can to minimise, or even eliminate our own contribution to climate change, but we should not be over confident that anything we do will actually stop climate change, rather than just reduce the impact.

 

Populist right vs Economic Conservatives

Donald Trump personifies the a populist right leader. This post looks at what this means and how this movement can be so at odds with other ‘conservatives’.

The Origin of The Conservative Right.

The basic origin of ‘left and right‘ in politics can from the wealthy and powerful being to seated to the right and the commoners being seated to the left in the assembly presenting to the king.  Those with power and wealth support those in power, that seems axiomatic. Then there are those that support those with wealth and power, not because themselves hold, wealth and power, but because they believe those people must have earnt that wealth and power.  The belief is that those who are deserving will achieve wealth and power, and must be encouraged to achieve that wealth and power.  Society benefits from the wealth and power generated by the wealthy and powerful.  The central idea of trickle down economics.   The left represented the commoners, who logically would benefit from the distribution of wealth and power to those the right may consider unworthy.  There is some merit in both arguments, as society does need to encourage and provide incentive to those who can excel, but there is also a case for sharing those rewards with those less fortunate.  Debating the ideologies is for another time.

The Rise of the Populist Right.

The populist right is basically ‘commoners’, who see themselves as currently more wealthy and powerful than other commoners, so they are embracing the position of the wealthy and powerful, relative to groups they feel threaten their wealth and power.  The groups the populist right fee threatened by are typically foreigners, immigrants and racial groups other than their own.  I would argue that the reality is that it is the ‘finite world‘ effect that is seeing this group feel the share of wealth and power they previously held eroded, and with no reason for their slide of their wealth and power presented, they rebel against change, immigration, free trade and are also receptive to messages against other changes such as any move to renewable fuels.

The Clash with The Conservative Right

While the populists are seeing their wealth and power eroded, the smaller group of those who have a much higher level of wealth and power are actually seeing their wealth and power rise as population grows and global free trade increases. This puts them in a very contrasting position with the populist group, although they do also tend to also fear change of the status quo.

Population – Wealth Equations

Formulae | Terms | Implications | Finite World

The formulae:

Annual-wealth-created = total-work-done + asset-wealth-accessed

Total-work-done = average-personal-productivity * population

Per-capita-wealth  =  average-personal-productivity  + (asset-wealth-accessed / population)

Asset-wealth-accessed = accrued-wealth + natural wealth-accessed

The Terms

Total Wealth.

The total wealth is simply the wealth of the society overall.  The sum of the wealth that is available for the total society to enjoy.  This wealth is available to be share evenly or not, but it represents that which is available to share.

Asset-wealth.

Asset wealth is the sum of durable wealth which remains from year to year such as housing and infrastructure as opposed to wealth which is consumed such as food and holidays.

Assets can be man made such as housing, or natural, such as the land under the housing, fertile farm land and water to grow crops or mines as a source of mineral wealth.  For natural wealth,  only those natural resources which are being utilised add to the wealth of the community at the time being considered.  Unused land or undiscovered minerals which may potentially be part of future wealth, do not add to current wealth.

Per Capita Wealth.

Simply the total wealth divided by the number of people.  In a society with perfectly even distribution of wealth, each individual would hold the per capita share of wealth.  Raising the Per Capita wealth would raise the wealth of all in the society.  However, simply adding to the wealth of one individual will still raise per capita wealth, even though there is no distribution of the increase in wealth.  Per capita wealth only is a sound indicator of overall wealth if wealth distribution remains static, and the rich remain in the same ratio of wealth to the poor.

Per capita wealth creation follow the formula above and combines individual wealth creation with the share of natural resource wealth.  Growing population should allow specialisation which can have a positive impact on the ability of an individual to produce wealth, but as the population grows this effect reaches a limit.  While there are untapped resources, growing the population can also allow accessing more resources,  but eventually all resources are already leveraged.  The result is that there is a phase where as population increases per capital wealth should increase, followed by a tipping point when all resources are fully exploited after which per capita wealth will be driven to decrease by further population grown.

The Implications: Pre-Finite world

Logically, total work done should increase in proportion to population. However, increased opportunities for specialisation and economies of scale can result in an increase in total work done slightly beyond the logical proportional increase. Simplistically, it is feasible for a team of 200 to do more than 10x the work of a team of 20 because of economies of scale and ability to specialise.  But a team of 200 trying to dig the same 3meter diameter hole in the ground may not be 10x as fast as team of 20.

Pre-finite world, natural asset wealth could never fully utilised, as there was always new natural assets to be found and utilised.  As population expands, more land can be utilised, more minerals discovered and the accessible total natural wealth expands as the population expands.  The result is that increase in population has the potential to increase per-capita wealth.

Finite World Implications

Once we reach ‘finite world’ where all new land has been found, and there is already sufficient people to exploit all available resources, more people simply means a smaller share of available land and resources per person.

Like digging the hole in the ground, there is an optimum number of people on the team.  Less than the number the work takes longer,  but past a certain point adding more becomes counter productive… or a least results in no further increase in production and the proceeds of the work on a per person basis start to decrease.

Once finite world is reached, further increases in population simple mean less wealth per person.  This is the same with any creatures in nature, within a given habitat, there is a maximum population of each creature which can be sustained by the habitat before living conditions start to decline.

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