An Exploration of Key Topics Shaping the Future.

Peak Child: When, and what does it mean?

When, is now. The data is real.

Peak child means the highest number of children the world will every experience.

Peak child comes prior to peak population, but it is almost certain to follow.

Peak child is a key indicator of population growth trends, and understanding the concept of ‘Peak Child’ is critical to and journey to understanding what is happening with population. The second point about Peak Child is the rather amazing fact, that the world may have already reached peak child, not yet reached peak population and probably won’t until 2055. This is a truth so contrary to preconceptions that even after seeing the data, it still seems hard to digest. The implications include the future of investments, economics, global warming, and how we picture the future of humanity, and the possibility of peak population.

Whilst long term population growth is not the normal state for any species, humans have experienced a population explosion over the most recent few centuries, such that our entire economic system now requires adjustment to deal with the end of the population explosion as countries such as Japan have learnt and China is poised to learn, and a return to historical normal.

What is ‘Peak Child’.


Peak Child is when the number of children has reached the maximum number it will reach, and understanding is step 3 the journey to understanding population trends.

Hans Rosling famously coined the term ‘peak child’ for the moment in global demographic history at which the number of children in the world stops increasing.

Our world in data“.

‘Peak Child’ can occur anywhere between 0 and 80 years (up to approximately 1 lifetime) prior to peak population, will typically occur at least approximately at 1/2 of one lifetime before a peak population level.

The exact definition of ‘peak child’ varies in one nuance: ‘What counts as a child?’. From birth until what age should count in the total for ‘peak child’. In different articles, different ages are chosen. It can be children in the first year only, children zero to five year old, or even all children under the age of 18. Which ‘upper limit’ is chosen can make a difference to when ‘peak child’ occurs, and to when.

Globally, peak child is determined by the ‘births per woman‘, which as a global average has been falling since 1960, being at or below the level for population stability, which is between 2.2 and 2.4.

Peak Child Vs Peak Population.

At a global level, due to the absence of immigrants to the Earth from other planets, ‘peak child’ is a precursor to peak population. For the global population to reach a plateaux, first number of newborn children must plateaux. Ten years later, the number of 10 year old reaches a peak. Twenty years later, the number of twenty year old people reaches the highest number it will ever reach, etc., until within a lifetime or about 80 years, no age group is increasing in population any more. As discussed below, it is logical humanity will soon also reach peak population.

Global Peak Child vs National Peak Child.

At the national level, there can be immigration, which means children at not the only source of population growth. Both immigration rates and birth rates vary from country to country, so that while globally we are peak child, some nations are still seeing child number increase, and other already had decreasing number for some years now. But it is inevitable at some point every country will reach peak child.

For a given country, reaching peak child means the number of schools can remain static and no longer need to handle expansion. Facilities for each demographic over time will also reach their peak requirement, unless changes to immigration or trends take place.

For an individual country, the link between the number of children and ‘births per woman’ is weakened due to immigration and emigration. For example, even with a ‘births per woman below 2.0’, the population could grow due to immigration. In fact, this is the reality for the USA, and many other countries with high net immigration. A growing population can, and as with the US currently does, result in an ever increasing number of children, even if the birth rate is not driving the increase.

Peak Child Is Natural, Normal, And Not Due To A ‘Boom’ in Births.

Yes, humanity has just experienced a population explosion, but it was not due to a boom in births. While in nature species do experience periods of population growth, these always result from displacing other species and reducing the populations of other species, and eventually a ‘normal’ population is reached.

Humanity has spend most of the 300,000 year history at some population plateaux, even though we have a history of moves to a higher plateaux which result in brief burst of growth, Eventually we must find a final normal on this finite planet, as we will eventually run out of other species to displace.

The Data: Are We Really There Yet? Really??

Peak Child Signalled in 2014 By Hans Rosling: Basically Correct, we have peak child.

The great Hans Rosling.

Hans Rosling declared we are already at peak child globally.

Hans Rosling was a great statistician, a wonderful humanitarian, but perhaps also an optimist. He stated the world is at peak child in 2014, when the ‘births per woman’ was at 2.5. Now, in 2019 it still marginally above 2.4, and the magic number, thought to be ‘between 2.4 and 2.2’, will be reached at the earliest by 2020, and at the latest by 2034. So for ‘peak child’ to have been already reached by 2014, it definitely could not have included all children under 18. Overall, you could argue that Hans was a little early, but not very early. We were basically at peak child at the time of his prediction, if not technically yet having already passed peak child.

2021 Update & Analysis: Peak Child From 2017 Confirmed By Birth Records.

Ourworldindata: Interactive

The graph to the right, which is available in interactive form at ourworldindata, uses UN data and projections. While the projections can be disputed, the data up to the current time is the most accurate available, and shows a gradual decline in births since 2017.

Two important points when analysing the data:

  • Both ‘births per woman’ and data for births should be considered together, as factors can cause a delay, or acceleration in families having children, without a change in the number of children.
  • While ‘peak child’ peak child occurs when children are born in the same numbers as their parents born 20-30 years earlier, deaths for the same year are biased towards the far smaller number of those born around 80 years earlier, when the population was smaller.

How did we get here: the global drop in births per woman.

This arrival at ‘peak child’ is the culmination of 60 years of continuously falling rate of ‘births per woman‘, which has fallen from 5 as a global average around 1960 when the population growth was out of control, to just over 2.4 today. Hans Rosling is the expert on the maths of how we got to here, and he has many theories on why the population has moved to a new stability, as do so many others, but I believe the best theory to be ‘normal population‘, that: all highly evolved species will normally naturally reproduce at close to the rate for a stable population.

Throughout human history, for all but the period for 1500-2000, humans reproduced at rate between slightly below, and just slightly above, the rate required for a stable population. In Hans Rosling’s words ‘they died in balance with nature’, but that required reproduction in balance with the number of children who would survive. As medicine in improved, survival improved, and birth rates fell to compensate. The balance is imperfect, in part because it takes at least one generation to make the adjustment. The recent population explosion resulted when infant mortality rates fell too quickly for birth rates to be able adjust. It seems we have now adjusted to a ‘new normal’ where very few children die before adulthood, by having between 2.2 and 2.4 children, which is well down from the historical average of 6.

OK: So Why do we still have Population Growth?

Some question, why are we not stopping population growth immediately? How can we be at peak child and the population still grows?

The population still continues to grow following for many years after peak child, as numbers of older age groups still increase until the first group of ‘peak children’ age into ‘peak adults’, and eventually ‘peak retirees’. Hans Rosling again has presents an explanation, as does this page on the population pipeline lag. I have now found others answering this same question.

In summary, there is a delay between ‘peak child’ and peak population, but once peak child is reached, the only thing that can stop peak population coming soon after is a reversal of trends in children per woman.

The Gap: Another 3 Billion?

At the time of writing the world population is over 7 billion. If we remain at the current ‘peak child’, which would be following the projections of Hans Rosling and those used by the UN as charted by ourwordindata, then population will reach almost 11 billion in future. On current trends, it is inevitable population numbers will peak, but as discussed later below, there is not universal agreement on at what number or even if current trends will continue.

Estimates vary between people pushing for a return to ever increasing numbers and increased birth-rates, and others who believe the trend of falling birth-rates does not magically stop at the current point, but will continue further.

Obviously, those wanting increased birth-rates believe population can keep growing, perhaps forever, while those who believe birth-rates will fall further anticipate potentially less than 10 billion people as a maximum, and a correction in global population for some time following that peak population.

In nature, while organisms experience periods of population growth as they displace other living things, no population ever continues growing indefinitely and instead finds a normal population. Perhaps we are beyond nature?

In summary, other outcomes are possible, but if everything remains at the current rate of births, then expect another 3 billion people before population stabilises.

Consequences: Don’t Panic, We Have Been Here Before.

We Have Been Here Before, and will be again.

Yes, we have had over 200 years of a population explosion, where the concept of peak child has seemed unimaginable, but for almost all of human history humanity has actually existed in a state of ‘peak child’.

Normally, even where there is population growth, it is so gradual that the number of children year after year will show no noticeable change even over a century.

Population growth of the recent explosion would carpet the entire surface of the Earth with humans within a few thousand years, and humans have existed for at least 300,000 years, so for almost all of those 300,000 years, humans have existed in a state of ‘peak child’. Prior to reducing infant mortality, there were more children per family, but as these were offset by child deaths, the population was stable. It has never been a problem existing in a state of peak child previously, or we would be extinct. It will, hopefully and most likely, not be the last peak child either, although perhaps the next population explosion will only happen if we manage to spread beyond one planet.

Consequences: An Economic Death Spiral?

One of the frequently pushed ‘pro population growth’ messages is that without population growth, economic doom awaits. This is not only fear of change, but also reflects that many economic indicators are tuned towards either tax revenues, or the results of only the largest companies, and thus biased towards population growth. Yet some of the best performing economies are either already post population growth(e.g. Germany), or at the stage where their only growing population demographic at this time, is the retiree group (e.g. China). In reality, any system that requires perpetual growth for prosperity has the characteristics of a Ponzi scheme.

Japan has suffered from a “crash” resulting from economic indicators that fail following “peak child”, and China appears poised for a similar crash. There is adequate proof that while those with the greatest wealth prosper during population growth, this is mostly due to increased inequity, and average wealth declines as population increases in any economy with sufficient people to access resources.

Consequences: The ‘ageing population’ myth?

The second frequently pushed ‘pro-population growth’ message is the ‘ageing population problem myth‘. Again, already debunked by some of the best performing economies already having dealt with this ‘problem’. Reality is high birth rate countries like Niger may have less old people, but with 50% of the population under 15, there is an even higher ration of people requiring economic support than in countries with an ageing population. Note also, the countries with an ‘ageing population’ are performing better economically that those with high population growth.

Why Have We Reached Peak Child?

The Question In Full: Why Have Birth-rates Fallen From 20th Century Average?

If someone had successfully predicted the fall in birth-rates from throughout the 20th century, then we could have confidence their hypothesis has been tested, but instead, we have proposals to explain the data after the fact.

Note, some ideas also explain what happened throughout human history, other only look at part of the 20th century.

I have a full page dedicated to examining what happened to

Option 1: Many Factors Including, The Pill, Educations of Women, Family Planning, etc

A popular approach is to look for factors in society that changed in correlation with the fall in birth-rates. The problem with this approach, is that it relies upon coincidence that the fall in birth-rates has corrected the imbalance created from the reducing infant mortality, which resulted in the population explosion.

Option 2: Since stable population was the normal in the past, we will return to stable population.

The big picture of human population is remarkable stability, and ‘peak child’ is the return to population stability. If population stability, as projected by UN and discussed by Hans Rosling is the natural balance, then births may remain at the current level for many decades to come.

Option 3: Like all advanced animals, humans adjust towards a sustainable ‘normal population’.

Another view, as modelled by Deutsche bank and other think tanks, is that nature seeks a to return to a ‘normal population‘, which achieves sustainability, then unless we interfere with nature, birth-rates may fall further still yet.

What next: will population numbers stabilise, or even decline?

The elusive ‘peak child’ has now been reached, so what now for future population? Whatever you wish to believe, there is a school of thought and material available to support that view.

Consider 2050. We already know the expected population for every age group over 30, as they have already been born. For the next few decades we know most of the story with population, but as each decade passes, there is another 10 years of population at a size yet to be determined.

Each of the three possible reasons why we are at peak child leads to a school of thought as to what will happen next with population. Either:

  1. Population will keep growing for ever, and ‘peak child’ is an abnormality that will come to an end.
  2. Humanity will remain at this ‘peak child’ level for decades to come, resulting in population growth slowing to zero in coming decades.
  3. The number of children born wiPopulation numbers will now stabilize, for now at least population growth population growth is headed towards zero, although it could still take time to get there.

1. Population Growth Will Return.

Simple maths, plus history of the last 2,000 years makes it very clear that the population growth rate of the last 2 or 3 hundred years is an exception, but for those who believe the Earth is only 6,000 years old, or like to ignore mathematical analysis of the time prior to records of population, it can be believed that while this does not happen long term for other living things, significant population growth is normal for humans.

With the mindset that population growth is normal for humans, comes the ideology that the factors that brought the reduction in birth rates must be overcome, so that growth can be restored. This mindset is strongly is promoted by those that profit from farming humans, and there is significant campaigns to promote this position. Move over big tobacco and big oil, we also have big population.

If this vision of the future is realised, despite the Earth being finite, there is be no limit to the human population.

2. Population Growth Will Head Towards Decades Of Stability With Births At Remaining At Reached Peak Child.

Taking more complete account of human history reveals that specific recent factors or not, population levels normal show remarkable stability.

With this model, working on the basis that human population trends towards reproducing at ‘replacement rate’ and population stability, assumes decades of remaining at the current peak child level, the global population will reach around 11 billion, and remain at that level until the balance is again disrupted.

3. Birth-Rates And Population Will Fall Until Humanity Achieves A Sustainable ‘Normal’ Population, As Large As Sustainably Possible.

This model, follows not only human history but also other examples of population in nature, and proposes that the observed population stability, arises from the fact that the maximum sustainable population normally remains stable for long periods of time.

Under this model, which is explored in more detail in the topic ‘normal population‘, it is possible that the current global population is unsustainable and in response the birth-rate may fall even further.

With this model, the global population may peak below even 9 billion.

The risks in future predictions.


Population numbers being significantly lower than projections, is likely only to occur following disasters. Disasters, do not only kill people, they also lower the carrying capacity of the Earth. A disaster that kills half the human population could result in a planet that, for a significant period, can only support half the previously population level. Further, society would likely be so disrupted by such an event that many systems simply fail, leaving the survivors without sewage, power, farming etc. Without all these systems, the Earth could feel more overpopulated than ever. So a disaster that decimates the population may make things better several hundred years later, but by the time things have recovered, the population could simply double again, with birth-rates like the 1960s capable of doubling the population in 30 years.

Climate change is one such potential disaster, but hopefully it can be averted. If fact, climate change and most other threatening disasters are all threats that arise due to Earth being above the carrying capacity.

Short of a disaster, the population cannot rapidly shrink. Remember the population pipeline. This year, the average elderly person do die would have been born 80 years ago when the world population was much smaller. To keep births to a level that only replaces a far smaller generation is a change that cannot happen that quickly.

Future Growth And Birth Rates?

Can the population grow higher than estimates? It is hard to see how that could be sustained. Even if some new social movement starts to reverse the trend of slowly decreasing birth numbers, the world dealing with environmental impact of the number of people we have will likely curtail any such movement.

Key to understanding what will happen with future birth rates is understanding what has happened that has caused rates to fall. In my opinion, many current theories do not stand real scrutiny, but even if these theories are correct, they also predict the trend in declining rates to continue. How far rates will decline depends on what theory you believe as to why rates declined, and I discuss that in leaving peak population.


Peak child is here. It marks a significant change, and while there being a similar number of children year on year is a return to normal, for a world where generations have known nothing but unsustainable, exponential population growth, some people will resist the change.


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