Global Overpopulation or Earth Equilibrium? Sergey Kapitsa

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Sergei Kapitsa, a well-known Russian popularizer of science, author of a model of the numerical growth of humanity, tells about why history is accelerating all the time, whether we are threatened with a demographic catastrophe and how the world will change during the lifetime of this generation.

Sergei Petrovich Kapitsa is a Soviet and Russian physicist, educator, TV presenter, editor-in-chief of the magazine "In the world of science", vice-president of the Russian Academy of Natural Sciences. Since 1973, he has continuously hosted the popular science TV program "Obvious - Incredible". Son of the Nobel Prize Laureate Pyotr Leonidovich Kapitsa.

This is one of the last articles by SP Kapitsa with answers to many questions of our time

After the collapse of science in our country, I was forced to spend a year abroad - in Cambridge, where I was born. There I was assigned to Darwin College; it is part of Trinity College, of which my father was once a member. The college focuses primarily on overseas scholars. I was given a small scholarship that supported me, and we lived in a house that my father had built. It was there, thanks to a completely inexplicable coincidence of circumstances, that I stumbled upon the problem of population growth.

I have dealt with the global problems of peace and balance before - something that made us change our point of view on war with the emergence of an absolute weapon that can destroy all problems at once, although it is not able to solve them. But of all the global problems, in fact, the main one is the number of people who live on Earth. How many of them, where are they being driven. This is the central problem in relation to everything else, and at the same time it was least solved.

This is not to say that no one thought about it before. People have always worried about how many there are. Plato calculated how many families should live in an ideal city, and he got about five thousand. Such was the visible world for Plato - the population of the policies of Ancient Greece numbered tens of thousands of people. The rest of the world was empty - it just didn't exist as a real arena for action.

Oddly enough, such a limited interest existed even fifteen years ago, when I began to deal with the problem of population. It was not customary to discuss the problems of the demography of all mankind: just as in a decent society they do not talk about sex, in a good scientific society it was not supposed to talk about demography. It seemed to me that it was necessary to start with humanity as a whole, but such a subject could not even be discussed. Demography has evolved from small to large: from the city, the country to the world as a whole. There was the demography of Moscow, the demography of England, the demography of China. How to deal with the world when scientists can barely cope with areas of one country? To get through to the central problem, it was necessary to overcome a lot of what the British call conventional wisdom, that is, generally accepted dogmas.

But, of course, I was far from the first in this area. The great Leonard Euler, who worked in various fields of physics and mathematics, wrote the main equations of demography back in the 18th century, which are still used today. And among the general public, the name of another founder of demography, Thomas Malthus, is best known.

Malthus was a curious figure. He graduated from theology department, but was very well mathematically prepared: he took ninth place in the Cambridge mathematics competition. If Soviet Marxists and modern social scientists knew mathematics at the level of the ninth rank of the university, I would calm down and think that they are sufficiently mathematically equipped. I was in Malthus's office in Cambridge and saw Euler's books there with his pencil marks - it is clear that he was completely proficient in the mathematical apparatus of his time.

Malthus's theory is quite coherent, but built on the wrong premises. He assumed that the number of people grows exponentially (that is, the growth rate is higher the more people already live on the earth, give birth and raise children), but growth is limited by the availability of resources, such as food.

Exponential growth to the point of complete depletion of resources is the dynamic that we see in most living things. This is how even microbes grow in the nutrient broth. But the point is, we are not microbes.

People are not beasts

Aristotle said that the main difference between man and animal is that he wants to know. But to notice how much we differ from animals, there is no need to crawl into our heads: it is enough just to count how many we are. All creatures on Earth, from a mouse to an elephant, are subject to dependence: the more body weight, the fewer individuals. There are few elephants, many mice. Weighing about one hundred kilograms, there should be about hundreds of thousands of us. Now in Russia there are one hundred thousand wolves, one hundred thousand wild boars. Such species exist in balance with nature. And man is a hundred thousand times more numerous! Despite the fact that biologically we are very similar to large monkeys, wolves or bears.

There are few hard numbers in the social sciences. Perhaps the country's population is the only thing that is unconditionally known. When I was a boy, I was taught in school that there are two billion people on Earth. Now it is seven billion. We have experienced this kind of growth over the course of a generation. We can roughly say how many people lived at the time of the birth of Christ - about a hundred million. Paleoanthropologists estimate the population of Paleolithic people at about one hundred thousand - exactly as much as we are supposed to in accordance with body weight. But since then, growth has begun: at first barely noticeable, then faster and faster, nowadays it is explosive. Never before has humanity grown so rapidly.

Even before the war, Scottish demographer Paul Mackendrick proposed a formula for human growth. And this growth turned out to be not exponential, but hyperbolic - very slow at the beginning and rapidly accelerating at the end. According to his formula, in 2030 the number of humanity should tend to infinity, but this is an obvious absurdity: people are biologically incapable of giving birth to an infinite number of children in a finite time. More importantly, such a formula perfectly describes the growth of humanity in the past. This means that the rate of growth has always been proportional not to the number of people living on earth, but to the square of this number.

Physicists and chemists know what this dependence means: it is a "second-order reaction", where the speed of the process depends not on the number of participants, but on the number of interactions between them. When something is proportional to "en-square", it is a collective phenomenon. Such is, for example, a nuclear chain reaction in an atomic bomb. If each member of the "Snob" community writes a comment to everyone else, then the total number of comments will just be proportional to the square of the number of members. The square of the number of people is the number of connections between them, a measure of the complexity of the "humanity" system. The greater the difficulty, the faster the growth.

No man is an island: we do not live and die alone. We reproduce, we eat, differing little from animals in this, but the qualitative difference is that we exchange knowledge. We pass them on by inheritance, we pass them on horizontally - in universities and schools. Therefore, the dynamics of our development is different. We are not just multiplying and multiplying: we are making progress. This progress is quite difficult to measure numerically, but for example, energy production and consumption can be a good yardstick. And the data show that energy consumption is also proportional to the square of the number of people, that is, the energy consumption of each person is the higher, the larger the population of the Earth (as if every contemporary, from Papuan to Aleut, shares energy with you. - Ed.).

Our development lies in knowledge - this is the main resource of humanity. Therefore, to say that our growth is limited by the depletion of resources is a very crude formulation of the question. In the absence of disciplined thinking, there are a lot of all kinds of horror stories. For example, a couple of decades ago, there was serious talk about the depletion of silver reserves, which is used to make films: supposedly in India, in Bollywood, so many films are being made that soon all the silver on earth will go into the emulsion of these films. It might have been so, but magnetic recording was invented here, which does not require silver at all. Such assessments - the fruit of speculation and sonorous phrases that are designed to amaze the imagination - have only a propaganda and alarm function.

There is enough food for everyone in the world - we discussed this issue in detail in the Club of Rome, comparing the food resources of India and Argentina. Argentina is one-third smaller in area than India, but India has forty times the population. On the other hand, Argentina produces so much food that it can feed the whole world, not just India, if it strains properly. It’s not a lack of resources, but their distribution. Someone seemed to be joking that under socialism the Sahara will have a sand shortage; it is not a question of the amount of sand, but of its distribution. Inequality of individuals and nations has always existed, but as growth processes accelerate, inequality increases: balancing processes simply do not have time to work. This is a serious problem for the modern economy, but history teaches that in the past, humanity solved similar problems - the unevenness was leveled in such a way that on the scale of humanity the general law of development remained unchanged.

The hyperbolic law of human growth has demonstrated amazing stability throughout history. In medieval Europe, plague epidemics carried away in some countries up to three quarters of the population. There are indeed dips on the growth curve in these places, but after a century the number returns to the previous dynamics, as if nothing had happened.

The greatest shock experienced by humanity was the First and Second World Wars. If we compare the real demographic data with what the model predicts, it turns out that the total losses of humanity from the two wars amount to about two hundred and fifty million - three times more than any estimates of historians. The population of the Earth has deviated from the equilibrium value by eight percent. But then the curve steadily returns to the previous trajectory over several decades. The "global parent" has proved to be stable despite the terrible catastrophe that has affected most of the countries of the world.

The link of times has broken

In history lessons, many schoolchildren are perplexed: why do historical periods become shorter and shorter over time? The Upper Paleolithic lasted for about a million years, and only half a million remained for the rest of human history. The Middle Ages are a thousand years old, only five hundred remain. From the Upper Paleolithic to the Middle Ages, history seems to have accelerated a thousandfold.

This phenomenon is well known to historians and philosophers. Historical periodization does not follow astronomical time, which flows evenly and independently of human history, but the system's own time. Its own time follows the same relationship as energy consumption or population growth: it flows the faster, the higher the complexity of our system, that is, the more people live on Earth.

When I started this work, I did not assume that the periodization of history from the Paleolithic to the present day logically follows from my model. If we assume that history is measured not by the revolutions of the Earth around the Sun, but by the lives of human lives, the shortening historical periods are instantly explained. The Paleolithic lasted a million years, but the number of our ancestors was then only about one hundred thousand - it turns out that the total number of people living in the Paleolithic is about ten billion. Exactly the same number of people passed through the earth in a thousand years of the Middle Ages (the number of mankind is several hundred million), and in one hundred and twenty-five years of modern history.

Thus, our demographic model cuts the entire history of mankind into identical (not in terms of duration, but in terms of content) pieces, during each of which about ten billion people lived. The most surprising thing is that such a periodization existed in history and paleontology long before the appearance of global demographic models. Yet the humanities, for all their problems with mathematics, cannot be denied intuition.

Now ten billion people walk the earth in just half a century. This means that the "historical era" has shrunk to one generation. It is already impossible not to notice this. Today's adolescents do not understand what Alla Pugacheva sang about thirty years ago: “… and you can't wait out three people at a machine gun” - which machine? Why wait? Stalin, Lenin, Bonaparte, Nebuchadnezzar - for them this is what grammar calls "pluperfect" - a long past tense. Nowadays it is fashionable to complain about the breaking of the connection between generations, about the dying of traditions - but, perhaps, this is a natural consequence of the acceleration of history. If each generation lives in its own era, the legacy of previous eras may simply not be useful to it.

The beginning of a new

The compression of historical time has now reached its limit, it is limited by the effective duration of a generation - about forty-five years. This means that the hyperbolic growth of the number of people cannot continue - the basic law of growth is simply bound to change. And he is already changing. According to the formula, there should be about ten billion of us today. And there are only seven of us: three billion is a significant difference that can be measured and interpreted. Before our very eyes, a demographic transition is taking place - a turning point from the unrestrained growth of the population to some other way of progress.

For some reason, many people like to see in this signs of impending disaster. But the catastrophe here is more in the minds of people than in reality. A physicist would call what is happening a phase transition: you put a pot of water on the fire, and for a long time nothing happens, only lonely bubbles rise. And then suddenly everything boils. This is how humanity is: the accumulation of internal energy slowly proceeds, and then everything takes on a new form.

A good image is the rafting of the forest along the mountain rivers. Many of our rivers are shallow, so they do this: they build a small dam, accumulate a certain amount of logs, and then suddenly they open the floodgates. And a wave runs along the river, which carries the trunks - it runs faster than the current of the river itself. The most terrible place here is the transition itself, where the smoke is like a rocker, where a smooth current above and below is separated by a section of chaotic movement. This is what is happening now.

Around 1995, humanity went through its maximum growth rate, when eighty million people were born a year. Since then, the growth has managed to noticeably decrease. A demographic transition is a transition from a growth regime to a stabilization of the population at the level of no more than ten billion. Progress, of course, will continue, but it will go at a different pace and at a different level.

I think that many of the troubles that we are experiencing - the financial crisis, and the moral crisis, and the disorder of life - are a stressful, disequilibrium state associated with the suddenness of the onset of this transition period. In a sense, we got into the very thick of it. We are used to the fact that unstoppable growth is our law of life. Our morality, social institutions, values have been adapted to the mode of development that has been unchanged throughout history and is now changing.

And it is changing very quickly. Both the statistics and the mathematical model indicate that the width of the transition is less than a hundred years. This despite the fact that it does not occur simultaneously in different countries. When Oswald Spengler wrote about "The Decline of Europe", he may have had in mind the first signs of a process: the very concept of "demographic transition" was first formulated by the demographer Landry using the example of France. But now the process is affecting less developed countries as well: the growth of the population of Russia has practically stopped, the population of China is stabilizing. Perhaps the prototypes of the future world should be looked for in the regions that were the first to enter the transition area - for example, in Scandinavia.

It is curious that in the course of the "demographic transition" countries lagging behind quickly catch up with those who took this path earlier. Among the pioneers - France and Sweden - the process of population stabilization took a century and a half, and the peak came at the turn of the 19th and 20th centuries. In Costa Rica or Sri Lanka, for example, which peaked in the 1980s, the entire transition takes several decades. The later the country enters the stabilization phase, the more acute it goes. In this sense, Russia gravitates more towards the countries of Europe - the peak of the growth rate was left behind us in the thirties - and therefore can count on a milder scenario of transition.

Of course, there is reason to fear this unevenness of the process in different countries, which may lead to a sharp redistribution of wealth and influence. One of the popular horror stories is “Islamization”. But Islamization comes and goes, as religious systems have come and gone more than once in history. The law of population growth was not changed by either the Crusades or the conquests of Alexander the Great. The laws will operate just as immutably during the demographic transition. I can’t guarantee that everything will happen peacefully, but I don’t think that the process will be very dramatic either. Perhaps this is just my optimism against the pessimism of others. Pessimism has always been much more fashionable, but I'm more of an optimist. My friend Zhores Alferov says that there are only optimists left here, because the pessimists have left.

I am often asked about recipes - they are used to asking, but I am not ready to answer. I cannot offer ready-made answers to pose as a prophet. I am not a prophet, I am only learning. History is like the weather. There is no bad weather. We live under such and such circumstances, and we must accept and understand these circumstances. It seems to me that a step towards understanding has been reached. I don’t know how these ideas will develop in the next generations; These are their problems. I did what I did: showed how we got to the transition point, and indicated its trajectory. I cannot promise you that the worst is over. But "scary" is a subjective concept.