Human population

For climate change, energy shortage, poverty, and any other existing problem we have, we tend to look elsewhere for solutions, except that one specific thing. It is always something or someone else to blame: our food habits, way of living, or animals and other beings, but rarely do we discuss that one thing: human numbers. It’s undeniably the biggest elephant in the room everyone is avoiding talking about.

In order to represent the total weight of land mammals, Randall Munroe (author of XKCD) used Vaclav Smil’s *2 book as the data source. His drawing is the simplest representation clearly showing that humans are taking up a significant portion of the entire land mammal mass of the planet, but more important is to notice that most of other animals exist only to serve human dietary needs. Wild animals, in comparison, which can roam freely, make up a very insignificant number. They are marked with green squares.

Land Mammals by XKCD *1

The question that arises as a consequence is: what is the maximum number of human beings that this planet can support?

Eminent Harvard University socio-biologist Edward O. Wilson wrote that, if everyone became vegetarians, our planet could support a maximum of 10 billion people *3 but the planet would only feed 2.5 billion U.S. omnivores.

Even by implementing the best agricultural practices and increasing food production while living at maximum numbers is not a good way to manage our life on planet. In any unforeseen event, like a Solar super flare, meteor collision, virus outbreak, change in weather patterns...we would be in danger of losing most of the Earth’s human population, and in technology sense reversing few hundred years back in history.

When we speak about sustainable numbers, we cannot speak only from the perspective of dietary needs. We have to keep in mind our impact on the climate, our energy requirements, and quality of life. Therefore, maximum numbers would largely depend on our habits, how much food we consume, how long we live, how much energy we use, what is our carbon footprint, etc. It is possible to calculate that, with current rates of consumption and ways of life, we need between 3 and 8 additional Earths *4 to satisfy all of our current needs.

Photo source: "Crowd" by James Cridland

The reason we have not experienced intense climate issues before now is due to the simple fact that people in other countries with large populations lived in economically poor conditions.

But, in the last few decades, new strong economies like China, India, and Brazil have emerged on the global scene, and the combined effect on planet’s climate is beginning to be more noticeable and significantly accelerated. This does not mean that we have to keep some countries in constant starvation and poverty levels, so that others could thrive; it only means that we need to manage our planet and our needs in a more sustainable way.

In any possible scenario, it would be more beneficial if we had a more sustainable number of people on the planet, at least until we find another habitable planet. Different studies are saying different numbers, but most of them agree that the most desirable long-term number would be the one we had in the 1950s and 1960s: 2.5 to 3 billion people.

In order to find ways to decrease the population number, we need to identify the reasons for growth. But simply decreasing the population number is not enough; we have to consider the ways to make our population sustainable in the long run, as we do not want end up with opposite problem facing extinction because of constantly decreasing numbers.

    The main reasons for population growth are many and tend to relate to one another:
  • economic - many studies have shown that, in a more developed society, people tend to have smaller families, favouring quality over quantity for their children. Also when contraceptives are widely available, the number of unwanted pregnancies is significantly lower. Developed tax systems and access to health care both contribute to longer lifespan but fewer newborns.
    In contrast, in undeveloped countries, multiple children are sometimes bred as an insurance policy for old age. Without a retirement fund, in many poor countries, children are considered an investment, as they were meant to take care of their parents after they cannot work or take care of themselves any longer.
  • health - the control of disease, infant mortality, and diet can impact population survival and extension of life expectancy. Although better care prolongs lifespan, thus having a positive impact on population growth, societies with more developed healthcare systems also have better birth control measures and sexual health education, which can prevent population growth.
    In countries without developed healthcare systems, sometimes the only way to combat diseases and infant mortality is by having more children. In that way, only those who are strongest will survive. This can cause a population explosion where, in order to survive, families have a significantly higher number of children.
  • social mechanisms – the availability of electronic communication and other forms of mass media, information delivery, energy networks, roads, clean water supply, care for the elderly, and insurance can all have different impacts on population growth.
  • cultural factors - religious attitudes can significantly impact population. In not-so-distant history, people were advised by religious authorities to have more children as the only way to combat diseases and other mortality factors, like floods, droughts, famine. Nowadays, religious attitudes about birth control can also significantly impact population growth, preventing abortion or even the use of condoms to prevent unwanted pregnancies. Often, as a consequence of religious beliefs and lack of education in some of the mostly-dense societies, childbirth is regarded as God’s responsibility, in which parents are relieved of their responsibility. Without responsibility for the child’s quality of life, parents will have multiple children, regardless of an inability to provide for them. It is believed that getting pregnant or not is by “God’s will,” and the child will live or die by this same force. In these societies, more children are also seen as a sign of God’s favouritism, thus giving parents a special status from having more children. Roles of women in society / sexual morality can also significantly impact population growth.
  • education – illiterate and uneducated people tend to have more children. In societies that have a need for higher education especially in societies where females have same opportunities as man to pursue knowledge and self fulfilment population does not grow at high rate. Additionally, sexual and health education can prevention unwanted pregnancies, and give people knowledge for better planning of their families.
  • environmental factors - environmental conditions that breed disease can significantly impact population growth. Climate change can severely impact population through droughts, floods, and storms, significantly influencing population fluctuation. Other natural disasters, like earthquakes, tsunamis, and volcano eruptions, can also have a negative impact on population growth.
  • political factors – the type of system, as well as personal freedoms and rights, can largely impact population growth. Impacts from war and conflicts, along with the strength of the economy, can largely create a structure that will either affect a decline or an increase in the population.

The present, widely-adopted capitalistic system has an expectation of constant economic growth. In order to sell more goods or services and satisfy constant GDP increases of a constantly aging population, the current political and economic ideology needs an ever-increasing population that will be able to “pay/work” out the debts created by previous generations.

The number of other beings on this planet largely depends on natural cycles and interdependence with other species, food and water availability, predators, and other environmental causes.

In our case, nature has failed to do the job efficiently. It is not that nature has not tried managing our numbers, but we have deflected everything that nature has thrown at us. Since the Second World War, all the storms, tsunamis, volcanoes, wildfires, floods, earthquakes, virus outbreaks, even wars have not done large damage to the overall human population.

Nature invented predators, but we created guns. Nature created wars; we invented peace and negotiations. Nature created diseases; we invented cures. Nature made people unable to give birth and made them sterile or homosexual, so they could not reproduce, but we invented artificial insemination. Regardless of what nature tried, we continued with our reproductive habits and the increase of our lifespan.

One thing is certain: we are terrible at managing our population numbers, and, in that sense, we behave more like bugs than intelligent species.

In 1972, when the planet had 3.84 billion human inhabitants, we used 85% of the biosphere’s regenerative capacity. Just 40 years later, the population has sharply risen to 7.3 billion, we use 150% of that capacity, and this number is still growing.*5

Currently, around 60 million people die and 130 million are born each year, adding 70 million people to the total population number. This level, combined with our way of life, is not sustainable. If we do not do anything, it will certainly push us to extinction.

Under the current circumstances, even applying more drastic policies like stopping the birth rate completely with a Zero-child-policy for 10 years, the population would only reduce to 6.9 billon from the present number.

We have put ourselves above nature’s cycles, but we have forgotten to act intelligently on a global scale, endangering our entire survival as a species. Now, we need to find intelligent ways to reverse course to a sustainable number for the good of everyone. It is necessary to brainstorm and discuss all possible options we have in reducing Earth’s population to a sustainable number.

It is not possible to speak about over-population without addressing consumption. Consumption usually reflects how much of the biosphere’s resources we consume, how much we waste, and what is our overall biosphere footprint.

Eleven out of the 196 countries in the world have half of the planet’s population and contribute more than 65% of total greenhouse gas emissions.*6 *7

Additionally, there is a correlation between global population and cattle production (directly causing large water, energy consumption and methane emission). We can see that those countries that have largest greenhouse gas emission also have largest cattle production. *8

Furthermore, correlating those findings with meat consumption *9 and the worldwide consumption of dairy products *10, we can pin-point which countries are causing the most greenhouse gas emissions, indirectly encouraging other countries to produce more meat and dairy products.

Just 24% of the total world population is responsible for almost 70% of total beef consumption and the corresponding methane emissions created by the cattle (water, energy, feed, burping, and manure).

In comparison to other top 24 countries, China has a relatively small beef consumption per-capita, but, because of the large population, overall beef consumption is high, although still almost half the size of the USA’s total consumption. Per capita, China is consuming around 6 times less beef than the United States, although its population is 4 times larger. If China would consume beef at the same rate per capita as the United States, it would consume a total amount of beef equivalent to the other 24 countries combined.

In order to solve the problems of overpopulation, overconsumption, and global warming; lowering greenhouse gas emissions; and making a more sustainable environment, those countries with small populations and large consumption have to reduce consumption significantly. Those with large population and low consumption per capita but large total consumption should look into ways to reduce their population numbers.

There are many ways to reduce the human population to sustainable numbers. Writing them all in one article would make it too long for a quick read, so I will create a series. Many methods I have found in books and internet, about which I would write in future, are regarded as taboo. Probably, many people would just avoid talking about them. Many methods are neither popular nor plausible — and in many ways quite controversial — as they look like they popped out from the head of some insidious mind. Regardless, I feel it is important to discuss them.