What is the upper limit of the population that the globe can bear to feed?

"Humans' unbridled desire to reproduce will eventually lead to an overpopulation of the planet, devouring all its resources, and dying in mass starvation," argued Thomas Malthus, a British philosopher, demographic researcher, and economist, in the late 18th century in an essay on his pessimistic vision of humanity's future.

But could doubling human numbers really push the planet to its limits?

And what is the ultimate power of the earth to produce subsistence for man?

More importantly, is it possible that Malthus' vision of the future is correct?

Some, including Sir David Attenborough, the famous British broadcaster and historian of nature, see human hordes as a "plague on Earth", where almost every problem of nature today can be traced back to climate change, biodiversity loss, water stress and land conflicts to overpopulation over the few centuries. past.

The Conversation also states that humans are consuming and polluting Earth's resources, such as aquifers, ice sheets, fertile soils, forests, fisheries and oceans, that have accumulated over geological time over tens of thousands of years or more.

As humans have colonized almost every habitat on the planet, their influence has reached even the most remote corners.

In 2018, scientists found a plastic bag at the deepest point in the ocean at the bottom of the Mariana Trench at a depth of 10,898 meters, while another team recently discovered so-called “eternal chemicals” man-made on Mount Everest, there is no longer a part of the world pure Because of what people do.

The number of people the planet can sustain is difficult to be constant because it depends on the way humans consume natural resources (Pixabe)

 The history of the inhabitants of the Earth?

The BBC reported that in 1994, when the world's population was only 5.5 billion, a team of researchers from Stanford University in California estimated that the supposed ideal size of the Earth's population was between 1.5 and two billion people.

Although the debate about the ideal number of people on this planet is endless, many scientists believe that the Earth has a maximum carrying capacity of 9 billion to 10 billion people.

Currently, approximately 8 billion people live on Earth, and according to the United Nations Population Division, we are on track to reach 9 billion by 2050 and 10 billion by 2100.

Our planet has never been so crowded before, according to Livescience, about 300,000 years ago, when Homo sapiens probably first appeared, the total population of Earth was small between 100,000 and 10,000 people.

Hence it took nearly 35,000 years for the number to double.

After the invention of agriculture about 15,000 to 10,000 years ago, there were between 1 million and 10 There are millions of people on Earth, and it took 1,500 years for the number to double.

By the 16th century, the time required for a population to double had fallen to 300 years.

By the turn of the 19th century, it only took 130 years.

From 1930 to 1974, the Earth's population doubled again in just 44 years.

Rich countries consume resources out of proportion to their population (Shutterstock)

Limited land capacity

According to NBCnews, apart from the limited amount of fresh water available, there is already a limit to the amount of food the Earth can produce, just as the philosopher Malthus argued more than 200 years ago.

Edward Wilson, a prominent Harvard University social biologist, wrote in his book, The Future of Life, that “if everyone agreed to become vegetarian and left little or nothing for livestock, 3.5 billion acres would currently be of arable land will suffice for about 10 billion people."

He explained that 3.5 billion acres would produce nearly two billion tons of grain annually, which is enough to feed 10 billion people, but he would only feed 2.5 billion carnivores, because a lot of plants are dedicated to livestock and poultry.

So 10 billion people, in his view, is the maximum population that the Earth can bear to feed.

Since it is highly unlikely that everyone will agree to stop eating meat, Wilson believes that the maximum carrying capacity of the Earth based on food resources is likely not to reach 10 billion.

For his part, Cohen says that there are some other environmental factors that limit Earth's carrying capacity such as the nitrogen cycle, available amounts of phosphorous and carbon concentrations in the atmosphere, but there is a great deal of uncertainty in the impact of all these factors.

It is also worth noting that rich countries consume resources disproportionately to their population.

According to the World watch Institute, the planet makes 1.9 hectares of land available for each person to grow food and products used in clothing and other activities such as heating and so on, while the average American consumes about 9.7 hectares.

These data alone suggest that the Earth can sustain at most one-fifth of the current population, 1.5 billion people with an American standard of living.

According to the Conversation website, in addition to food, water is very important for all living things. Biologically speaking, an adult human needs less than 1 gallon (about 4 liters) of water per day, but in 2010, for example, every individual in The United States has more than 1,000 gallons (4,000 liters) of water per day, distributed as follows: half for electricity generation, a third for irrigation, and about a tenth for domestic use.

Thus, if the Earth's population consumes water at US levels, the global use will exceed 10,000 cubic kilometers per year, while the total global supply of freshwater lakes and rivers is about 91,000 cubic kilometers.

WHO figures show that 2.1 billion people actually lack access to safe drinking water.

Due to the decline in the global fertility rate, the Earth's population is expected to stabilize between 9 billion and 10 billion (Pixaby)

End time stage

The number of people the planet can sustain is difficult to be a fixed number, because it depends on the way humans produce and consume natural resources.

One study, published in the Proceedings of the National Academy of Sciences, found that if the US population switched to a vegetarian diet, that would be equivalent to feeding 350 million Americans on top of the current number.

The bottom line is, according to scientists, there may be a maximum number of people the Earth can handle, but we don't know exactly what that number is, because it varies based on how we produce, consume and manage our resources.

Fortunately, we may be spared the end times because of the overpopulation and famine that Malthus depicted.

According to the United Nations Population Division, although we are on track to reach a population of 9 billion by 2050 and 10 billion by 2100, its estimates of global population trends show that the number will then dwindle.

Gerhard Heilig, head of the United Nations Population Estimates and Prospects, says empirical data from 230 countries since 1950 shows the vast majority have had declines in fertility.

Globally the fertility rate is falling to the "replacement level", roughly two children per woman, which is the rate at which children replace their parents, and if the global fertility rate does indeed reach replacement level by the end of the century, the population will stabilize between 9 billion and 10 Billions.