Causes and consequences of overpopulation

Human population is growing exponentially. What will this mean in the future?
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Fewer than 800 million people populated the Earth in the mid-18th Century. Today, barely 250 years later, we are more than 7.5 billion and will continue growing until 2050, the moment at which forecasts point to a stabilizing of the world population.

Taking into account the fact that human beings appeared on Earth more than four million years ago, what happened in our recent history for the number of inhabitants on the planet to start multiplying exponentially? The tipping point was generally accepted to be the Industrial Revolution, but there are many smaller revolutions that contributed to population take-off which have brought the planet to its current dangerous overpopulation: revolutions that are medical, technological, agricultural, financial, transport and demographical in nature, among others.

Do you want to know what causes overpopulation?


Causes of overpopulation

It took hundreds of years to reach one billion inhabitants, yet in little over two centuries this figure multiplied sevenfold. Why? There are a series of factors that favored the spectacular growth:


  • Falling mortality rate, mainly due to medicine: the Industrial Revolution brought with it a revolution in the world of medicine. Scientific progress allowed us, from then onward, to overcome diseases that previously could only end in death. The invention of vaccines and discovery of antibiotics such as penicillin saved thousands of lives and were a key factor in unfettered population growth. As the number of annual deaths fell, while births remained constant, so the population increased.


  • Progress in food production: for its part, scientific research and technological improvements saw more efficient agricultural production, resulting in year-round crops, more resistant seeds, pesticides, and so on…. aspects that Malthus had not taken into account when putting forth his catastrophic theory condemning the human race to disappear. Improvements In fishing and livestock methods also contributed to the provision of more food with which to nourish the population.


  • Migration and urban concentration: in certain countries, the impact of migration and accumulation of the population in cities was very important, but not only with respect to demographic growth, but also in relation to wealth generation. Currently, over half the global population live in cities of more than 300,000 inhabitants and which are expected to continuing growing until they reach 70% of the population. 

Over the past 200 years, the global population has multiplied sevenfold #Overpopulation


Effects of overpopulation

What does this constant growth mean? There are several direct consequences of overpopulation:

Causes and consequences of overpopulation

  • Exhaustion of natural resources: the main effect of overpopulation is the unequal and unrestrained use of resources. The planet has a limited capacity to generate raw materials and each year the natural resources deficit – the consumption of resources at a faster rate than the planet is able to generate them – is reached earlier. Consequently, in developing countries, overpopulation causes fierce rivalries to control resources. Territorial conflicts over water supply are due in many cases to geopolitical tensions and can end in war.


  • Environmental degradation: unbridled use of natural resources, as well as growth in energy production from coal, oil and natural gas (fossil fuels) is having a negative impact on the planet. Consequences number, on the one hand, deforestation and desertification, extinction of animal and plant species and changes in the water cycle and the most direct consequence of all in the form of emissions of large quantities of greenhouse gases leading to global warming.


  • Rising unemployment: on the other hand, a high number of workers exist for a limited number of vacancies and this seems destined to lead to high rates of joblessness in the future. This in turn could provoke rising crime and social revolt.


  • Rising living costs: all the above will lead, at the end of the day, to increasing living costs in most countries. Fewer resources, less water, the packing of many people into confined spaces and a lack of money are provoking an increase in the cost of living whereby only a percentage of the population will be able to cover all their needs.


  • Technological advances: on the positive side, high concentrations of people in urban areas also brings with it research and development in the quest for solutions to the population’s needs. An example is the popularisation of communication technologies and the generation, collection and use of Big Data for sustainable ends, as well as the emergence of Smart Cities adapted to ensure good living conditions for the increasing population.

As you can see, the impact of overpopulation is tremendous. Overpopulation is one of the biggest challenges humanity is facing and threatens the near future of the planet in economic, environmental and social terms.


Sources: United Nations Population Fund, World Population History, Our World in Data, Info Laso,, Conserve Energy Future, BBC, Sociology Discussion, Population Matters, Fertilab, Expansión and Naciones Unidas.


Jos Eussen


Overpopulation is, although it sounds harsh, not just an important factor but the main threat for a sustainable future. Forecasts of over 11 billion in 2050 force us to now build consumption patterns we can sustain.


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