Why is Overpopulation Ignored by the Media? The Reasons of a Historical Failure

Some people think there exists a conspiracy that prevents the media from ever mentioning the charged word, "overpopulation." Conspiracies do exist but, in this case, my impression is that population is such a charged issue simply because it has to do with the fact that we are all humans and discussing about reducing population touches some inner mechanisms of our psyche that we feel uncomfortable about.

But there is more to that: the real problem with overpopulation is that most decision makers lack the concept of "overshoot,"  a view that didn't exist in the study of social systems until Jay Forrester introduced it in the 1960s.If you don't understand overshoot, at best you can understand that there are limits to population, but you can't understand that population could exceed the limits and crash down ruinously with the deterioration of the agricultural system that feeds it.

The lack of a the concept of overshoot may well be what leads the concerned and the unconcerned to minimize the problem. Many people seem to think that the "demographic transition," the reduction in fertility observed in most rich nations of the world, will spread over all humankind and stabilize the world's population at a sustainable level without any need for governments to intervene to force lower birth rates.

Almost certainly, it is too late for that: we should have started decades ago. But only China implemented a serious policy birth control -- for the rest of the world it was a historical failure.

In the discussion, below, Bernard Gilland discusses the problems we will face in the attempt of stabilizing the human population mainly in terms of the degradation of the agricultural system in its dependence on non-sustainable resources. It is not the only problem, with climate change potentially able to do even more damage to agriculture. At the same time, the many young people in poor countries will push population onto a still growing trajectory. If these two tendencies, population growth and agricultural decline, crash against each other, the result might well be a Seneca Cliff for the world's human population.

A sustainable global population -and why we cannot achieve it

Guest Post by Bernard Gilland


In the period 1975 – 2018, world population increased at an average of 83 million per year, and reached 7.6 billion in 2018. The increase in 2017 was the difference between approximately 145 million births and 62 million deaths. Despite population growth, the global average daily food supply per person rose from 2440 kilocalories in 1975 to 2940 kilocalories in 2015 (1). However, over 800 million people are undernourished and 300 million adults are obese.

Cereals are the most important crops for food and feed; globally, 45 percent of the cereal production is consumed by humans, and 35 percent by livestock. The remainder is used for industrial purposes, including ethanol, beer, whisky and vodka. The rise in world cereal production since the 1960s is mainly due to two technological advances. The first was Haber-Bosch ammonia synthesis, in which atmospheric nitrogen is fixed as ammonia (containing 82 percent nitrogen) which plants utilize for protein formation. Production of Haber-Bosch ammonia began in 1913, but did not begin to rise rapidly until the 1960s. The second advance was the Green Revolution that began in the mid-1960s, after agronomist Norman Borlaug had bred varieties of dwarf wheat that give higher yields in response to heavier applications of nitrogen, phosphorus and potassium fertilizer, pesticides and irrigation. The breeding and use of semi-dwarf rice and hybrid maize paralleled that of wheat.

The most striking achievement of chemical agriculture is the maize yield in the U.S., which rose from 2.5 tonnes per hectare (40 bushels per acre) in 1950 to 11.0 tonnes per hectare (175 bushels per acre) in 2016. The global cereal yield rose from 2.81 tonnes per hectare in 1992-96 to 3.91 tonnes in 2012-16 (2). Linear extrapolation of the 1992 - 2016 yield trend (52.3 kg per hectare per year) gives a yield of 5.73 tonnes per hectare in 2050. If the population in 2050 is taken as 9.85 billion (3), and the harvested cereal area remains 718 million hectares (as in 2016), production per person in 2050 would be 420 kg, 10 percent above the 2016 level of 382 kg; the uncertainty is about 10 percent either way. Assuming that the global average cereal yield without using nitrogen fertilizer is 1.6 tonnes per hectare, and that fertilizer increases grain yield by 30 kg per kg nitrogen applied, the global average nitrogen application on cereal crops, 80 kg per hectare in 2015, would be approximately 140 kg per hectare. If the incremental yield-nitrogen ratio rises to 35 by 2050, the nitrogen application would be 120 kg per hectare.

The success of the Green Revolution created three major ecological problems:

1. Globally, about half the applied nitrogen is taken up by the crop plants; the remainder volatilizes in the form of ammonia and nitrous oxide (a powerful greenhouse gas) or leaches to groundwater, resulting in eutrophication (the formation of algae) in rivers, lakes and coastal waters; this creates “dead zones” in which fish cannot live.

2. Applying nitrogen, phosphorus and potassium fertilizer to crops changes the balance between these nutrients and those needed in small or trace amounts; the latter include calcium, sulphur, magnesium, iron, manganese, copper, zinc, cobalt, boron and selenium.

3. Approximately 40 percent of global irrigation water is obtained by pumping groundwater from tube wells; this has resulted in the depletion of aquifers and the lowering of groundwater levels, thereby contributing 0.4 mm to the global sea level rise of 3.4 mm per year (4).

As population growth increases the need for fertilizer, it follows that population reduction would ultimately solve the ecological problems. Unfortunately, human nature is such that global population reduction is not feasible. The reasons for this are given in the following.

In 1950, France had a population of 42 million and 20 million hectares of arable land, i.e. 2 persons per arable hectare. The nitrogen fertilizer application on cereals was negligible, and cereal production per person was about 400 kg per year, slightly higher than the present world average. If the ratio of population to arable land were 2 persons per hectare on the world’s 1.6 billion arable hectares, world population would be 3.2 billion. Reducing world population to this size would mean reducing the global average fertility rate (currently 2.5 children per woman) to 1.5 by 2050 and holding it at that level until 2200. The proportion of the population in the 65+ age-group would rise to 35 percent. Such a drastic change in the age distribution would mean raising the pensionable age to 70 years or more.

Adopting and enforcing a population limit for each country would be an insurmountable obstacle, as Charles Galton Darwin pointed out in 1952 (5). To lower the global average to 2 inhabitants per arable hectare, countries such as Canada, Russia, Australia and Argentina would not be required to reduce their populations, but would not be permitted to reach 2 inhabitants per arable hectare; they would be obliged to have a grain surplus for export to countries that need grain imports. China and India would each have to reduce its population to roughly 300 million; the combined population of the two countries would then be 20 percent of the world population instead of the present 35 percent (6). The relative population reductions in Japan and Egypt, which have 30 and 33 inhabitants per arable hectare respectively, would be much greater (6).

The population of China is projected to peak at 1.45 billion around 2030 and decline to one billion by 2100. This is partly a result of the so-called one-child policy launched in 1979 (in reality a 1.5-child policy). It was replaced by a two-child limit in 2016, but the fertility rate remains 1.6. Japan has a population of 126 million and a fertility rate of 1.4; the population is projected to decline to 102 million in 2050 and 60 million in 2100. These projected long-term declines are likely to be halted by pro-natalist policies based on the advice of growth-obsessed economists who believe that population decline results in a shortage of labour. A world population peak of at least 10 billion is almost inevitable, and this would make 70 percent of the world’s population dependent on Haber-Bosch ammonia. This is not sustainable, but there is no solution in sight. As a sustainable population cannot be attained by fertility decline alone, a mortality rise is highly probable. We can only guess when.


Bernard Gillan is an independent researcher with a degree in Engineering, based in Copenhagen, Denmark. He is the author of several papers on demography and population



NOTES AND REFERENCES

1. FAOSTAT data.

2. World Bank data.

3. Population Reference Bureau. World population data sheet 2018.

4. Konikov, L.F. 2011. Contribution of global groundwater depletion since 1900 to sea-level rise. Geophysical Research Letters, 38; L17401.

5. Darwin, C.G. 1952. The next million years. Hart-Davis, London.

6. Lionos, T.P., A. Pseiridis. 2016. Sustainable welfare and optimum population size. Environment, Development and Sustainability, 18(6), 1679 - 1699. According to the authors, the optimum population of the world is 3.1 billion, and the populations (in millions) of the ten most populous countries are:

China 253, India 341, United States 326, Indonesia 88, Brazil 156, Pakistan 43, Nigeria 79, Bangladesh 17, Russia 249, Japan 9.2. The figure for Egypt is 7.4.

Jay Forrester: the man who saw the future

Jay Wright Forrester (1918-2016) may have been the source of inspiration for Hari Seldon, a fictional character in Isaac Asimov's Foundation series. In Asimov's novels, Seldon develops "pyschohistoric equations" that allow him to predict the impending collapse of the Galactic Empire. In the real world, Forrester developed "system dynamics equations" that allowed him to predict the impending collapse of the modern human civilization. The predictions were ignored by the Imperial powers of both the fictional and the real universe.

Jay Forrester, one of the great minds of the 20th century, died at 98, a few days ago. His career was long and fruitful, and we can say that his work changed the intellectual story of humankind in various ways, in particular for the role he had in the birth of the Club of Rome's report "The Limits to Growth"

In 1969, Forrester was a faculty member of the MIT when he met Aurelio Peccei in Italy. At that time, Peccei had already founded the Club of Rome, whose members were worried about the limits to the natural resources that the Earth could provide. They were trying to understand what the consequences would have been for humankind. From what Peccei wrote, it seems clear that he was seeing the situation mostly in Malthusian terms; thinking that the human population would have been growing until reaching the resource limits, and then stay there, kept in check by famines and epidemics. The main concern of Peccei and of the Club of Rome was to avoid human suffering by ensuring a fair distribution of what was available.

The encounter with Forrester changed this vision in ways that, perhaps, neither Peccei nor any of the Club members would have imagined. In the 1960s, Forrester's models were already well advanced. Based on a completely new method of calculation that Forrester had dubbed "system dynamics," the models were able to take into account how the many variables of a complex system interacted with each other and changed in time.

The result was the study that the Club of Rome commissioned to Forrester and to his research group: simulate the future of humankind over a time range of more than a century, all the way to 2100. Forrester himself prepared a complete study with the title "World Dynamics" that was published in 1971. A group of Forrester's students and coworkers prepared a more extensive study titled "The Limits to Growth" that became a true intellectual revolution in 1972.

Forrester's system dynamics provided results that proved that Malthus had been an optimist. Far from reaching the limits to growth and staying there, as Malthus had imagined, the human civilization was to overshoot the limits and keep growing, only to crash down, badly, afterward. The problem was not just that of a fair distribution of the available resources, but to avoid the collapse of the whole human civilization. The calculations showed that it was possible, but that it required stopping economic growth. That was something that nobody, then as now, couldn't even imagine to do.

You know how things went: I told the story in my book "The Limits to Growth Revisited". Forrester's work was mostly ignored, but the better known "The Limits to Growth" study was not only rejected; it was actively demonized. The legend of the "wrong predictions" of the study was created and it spread so much that it is still widely believed. Yet, the intellectual revolution that was the creation of System Dynamics never died out completely and, today, world modeling is returning. We need to study the future in these times of great uncertainty. It is difficult, unrewarding, and often leading us astray. But we must keep trying.

Perhaps of Forrester's unknown achievement was of having inspired Isaac Asimov for the character of "Hari Seldon" in the famous "Foundation" series that Asimov wrote starting in the 1950s. We have no proof that Asimov ever met Forrester or knew his work, but they both lived in Boston at the same time, so it is at least possible. Then, Hari Seldon and Jay Forrester share similar traits: both are scientists who develop powerful methods for prediction the future. Seldon develops a field known as "Psychohistory" while Forrester developed "System Dynamics." In both cases, the equations predict that civilization will undergo a collapse. In both cases, the scientists are not believed by the Imperial authorities of their times, fictional or real.

In Asimov's story, Seldon goes on to create "Foundation" a planet where the achievements of civilization are kept alive and will be used to rebuild a new civilization after that the collapse of the old one. The plan succeeds in Asimov's fictional universe. In our case, the real Earth of the 21st century, nobody seems to have been able to create a safe haven for the achievements of civilization that we can use after the collapse. Seeing how things stand, maybe it is the only hope left?


But, maybe, Asimov wasn't directly inspired by Forrester for his Hari Seldon. Maybe he was just inspired by the archetype of the wise man that, in human history, has been played by people such as Merlin, Laozi, Kong Fuzi, Prince Gautama, Socrates, and many others. Perhaps Jay Forrester deserves to be listed among these wise men of old. Perhaps, the wisdom that Forrester brought to us will come handy in the difficult future that awaits us.



Forrester's achievements are many besides those of World Modeling. He developed a completely new magnetic computer memory that became the world standard, he developed a complete programming language (called "dynamo"), he is the originator of several fundamental ideas in system management: the "bullwhip effect," the concept of "Urban Dynamics"; of "Industrial Dynamics" of the "leverage points" in complex systems, and much more. A true genius of our times.