In 1798, a book titled An Essay Concerning the Principle of Population by Thomas Robert Malthus came to light. His ideas about the consequences of an increase in the human population and the need for control raised blisters in a society that thought that the wealth of a nation depended on its number of inhabitants.
Here are some of Malthus’s ideas embodied in his work:
[…] In order to avoid any exaggeration, let us take as the basis of our reasoning the less rapid increase (of the human population): accredited by many testimonies, and that it is true that it comes only from births.
We can therefore establish as certain that when no obstacle prevents it, the population doubles every 25 years, growing from period to period in a geometric progression.
It is not so easy to determine the measure of the increase in the productions of the earth; but at least we are sure that it is very different from that which is applicable to the increase of the population. A number of billions of men must double in 20 years by the sole principle of population, as much as a number of thousand men. But the necessary food to feed a greater number will not be obtained with the same ease, since man only has a limited space. When a bushel of land joins another bushel, when, finally, all the fertile land is occupied, the increase in food depends on the improvement of the land already cultivated, which, by the nature of all kinds of land, will not do great On the contrary, the progress that it makes will be less and less considerable: while the population, while it finds what to subsist on, does not recognize limits, and its progress is an active cause of new increases. […]
[…] Let us replace this law that has served as an example, the surface of the earth: and of course it will be known that it is not possible to resort to emigration to avoid hunger. Let us suppose the number of inhabitants of the earth to be one billion: the human race would grow as the numbers 1, 2, 4, 8, 16, 32, 64,128, 256, while subsistence as these: 1, 2, 3, 4, 5, 6, 7, 8, 9. After two centuries the population would be subsistence as 256 is as 9: after three as 4,096 is as 13 and after two thousand years the difference would be immense , incalculable.
It is seen, then, that in our suppositions we have not assigned any limit to the products of the earth. We have conceived them as susceptible to an indefinite increase, as wanting to exceed any limit, no matter how great the one designated. On this same supposition, the principle of population from period to period is so superior to the productive principle of subsistence that, in order to maintain itself at the level, in order for the existing population to find adequate food, it is necessary that a law impede this progress at every instant. superior: that hard necessity submits it to its empire: in a word, that one of the two contrary principles whose action is so preponderant, is contained within certain limits.
Malthus’s predictions have not come true to the letter, but the threat of overpopulation continues. Let’s analyze the evolution of the human population throughout its history to the present day.
It is estimated that 2,000 years ago, there were 170 million people on Earth, a number that had been reached after more than four million years of evolution. A thousand years later, humanity was made up of about 250 million people, that is, in a thousand years it had increased by 80 million. A trifle when compared to the increase that has taken place during the last year, 2010, which has been 83,315,475 inhabitants according to the Population Reference Bureau.
In the year 1575 the population had doubled, that is, 500 million. From then on, there is a dizzying escalation. In 1800, shortly after Malthus published his Essay on the principle of Populationthere were about 1 billion human beings on planet Earth.
The number of inhabitants doubled again in 1927, reaching 2,000 million. And it did it again in 1974, in just 47 years the population reached 4,000 million people. According to the 2010 World Population Data Sheet, the global population is currently around 6.9 billion and continues to grow at a rate of almost 7 million human beings per month, a population the size of Switzerland, every month.
And the question is…until when?
world population clock
Essay on the principle of population