by Nefeli Athanasaki.

Humans have been inhabitants of the Earth for more than 200.000 years. Since the industrial revolution though, humanity has begun to intervene dramatically with nature. Due to technological advancements, everyday life has improved, the healthcare system has evolved and life expectancy has gradually risen. This entire human revolution was going to show its real side effects some 200 years later when the human population would rise from 1 billion in 1800 to 7 billion in 2000 (Roser, Ritchie, Ortiz-Ospina, 2020).  According to a United Nations study, currently, the world population is at 7,6 billion people and is expected to reach 8,6 billion by 2030, 9,8 billion by 2050 and 11,2 by 2100 (United Nations Department of Economic and Social Affairs, 2017). That includes a growth of 2,1 billion people in 30 years, which is less than one generation. Due to this growth, overpopulation has become a significant issue, because of the negative effects mankind has caused and continues to cause to the environment. A definition for overpopulation is that the population of a region or the planet exceeds its carrying capacity which is the number of people, other living organisms and crops that can be supported without environmental degradation. (LeBlanc, 2020). 

Such a drastic proliferation of the population causes augmentation of needs. Hence, more carbon footprints, cars, waste, emissions, house constructions, infrastructure, more water, food, resources and energy production are required (Whiting, 2018). The problem here is, that although many of the Earth’s resources are finite, human demands are so high of maintenance that we use resources equal to 1,7 times the rate at which the planet can renew them (, 2020). But, based on an MIT study, if those resources are converted to become more efficient, then that would entail less usage of them. The bigger the efficiency is, the smaller it makes the price of the product, the increase of the demand and usage and ultimately makes the commodities more affordable (Chu, 2017). The same study argues that there is a great need for dematerialization, but with new technological progress, the demand for its usage rises accordingly to cover the needs of the growing population.

Overpopulation is associated with negative environmental phenomena. One of which is water pollution and its overconsumption. Only 2,5% of the water on the planet is freshwater.  Of that friction, 1% is either polluted for consumption or entirely unreachable and the majority of the rest remains frozen, thus leaving less than 1% of fresh water available for consumption. As humans, we consume this small percentage of freshwater faster than the planet can replenish it (Ray Nichols, 2020). Another issue is that human populations exploit habitats along with their water and food supplies, hence leading to mass flora and fauna extinctions – something also realized by global warming-. The scientific community predicts that by 2050 more than half of the plant and animal species of the planet will face possible extinction, due to habitat loss, pollution and climate change. The collapse of entire ecosystems will become inevitable and will cause further extinction of surviving species (Ray Nichols, 2020). On top of that, the planet keeps warming faster than usual, from human-generated greenhouse gasses. Atypical weather patterns derive from this phenomenon such as multiple category 5 hurricanes, worldwide wildfires etc. So, the more human population rises, the more gases will be emitted causing an immediate impact on the planet (Ray Nichols, 2020). Also, more people mean greater needs for more crops and higher production rates. In order for those needs to be covered, farmers farm excessively causing soil depletion. When the soil of an area is deprived of its natural resources, then that area could conceivably be characterized as abortive. As a result, large forest areas are deforested drastically -increasing soil erosion-, in an effort to make new farmlands and meet with the food demands of the human population (Ray Nichols, 2020), making agriculture responsible for 80% of the worldwide deforestation (Kissinger, Herold, and De Sy, 2012). However, soil degradation is also caused by chemical-heavy farming techniques and global warming. In our days, almost a third of the world’s soil has already been degraded, when 3cm of topsoil takes 1000 years to generate. A study showed that because of the growing population rates, arable land per person by 2050 will be a quarter of the level it was in 1960 (Arsenault, 2014). In addition, there are more than 400 marine dead-zones worldwide which are caused by eutrophication, collectively covering an area six times the size of Switzerland (Norwegian University of Science and Technology, 2018).  Eutrophication is caused by industry and sewage disposal -both related to population growth- and describes the dense growth of plant life that consumes oxygen, resulting in the death of aquatic animals in an area  (LeBlanc, 2020).

Water scarcity and land degradation are likely to increase vulnerability and food insecurity in Africa and Asia (The Food and Agriculture Organisation of the United Nations and Earthscan, 2011). In more detail, a Harvard study has shown that the majority of the population to be increased in the next 40 years will be in less developed countries. This will lead to a higher mortality rate and a lower life expectancy because of problems associated with infrastructure, water, housing and food (Bloom, 2020). Overpopulation and climate change put Asia – where 61% of the global population lives- in danger of flooding. Specifically, the Indonesian capital Jakarta along with its suburbs is expected to be entirely submerged by 2050 due to the continuous extraction of groundwater, a process that speeds up the rate in which the city is sinking (, 2020). Also, according to the United Nations, the populations of 26 African countries are due to at least double in size between 2017 and 2050. Nigeria is the 7th larger country in the world and by then it will take the USA’s 3rd place in the ranking. That change will be realized because fertility levels in the world’s 47 least developed countries are 4,3 births per woman (United Nations Department of Economic and Social Affairs, 2017).

The USA also faces many challenges from overpopulation-relating issues. A 2009 study of the relationship between population growth and global warming determined that the carbon legacy of just one child can produce 20 times more greenhouse gas than a person will save by driving a high-mileage car, recycling, using energy-efficient appliances, light bulbs, etc. Each child born in the United States will add about 9,441 metric tons of carbon dioxide to the carbon legacy of an average parent. The study concludes, “Clearly, the potential savings from reduced reproduction are huge compared to the savings that can be achieved by changes in lifestyle” (Murtaugh, Schlax, 2020). But the carbon legacy is tied to consumption patterns and under the current conditions, a child living in the US will be responsible for almost seven times the carbon emissions of a child living in China and 168 times of a child living in Bangladesh (Center of Biological Diversity, 2020). For individual nations, it is difficult to calculate the exact carbon footprint because of the globalization of the economy. That happens because many countries like the US transfer their production to other countries like China, making China emit more greenhouse gas which in reality is the displaced footprint of high production western nations (Center of Biological Diversity, 2020). While the US holds the record of the biggest population along with the developed countries, it’s the only nation experiencing significant population growth, with many studies supporting that the population may even double. The present 300 million inhabitants produce greenhouse gases at a per-capita rate that is more than double that of Europe, five times the global average and more than 10 times the average of developing nations. This greenhouse gas production is the outcome of high population, transportation (an average American drives 3 trillion miles per year), a dramatic increase of average home sizes (therefore demanding more energy for heating or cooling) and massive never-ending consumption levels, and thus far, lack of political will to end the fossil-fuel addiction. All of these trends exacerbate the carbon footprint inherent in the basic energy needs of a burgeoning U.S. population (Center of Biological Diversity, 2020).

At the other end of the spectrum, like every other problem, overpopulation has solutions. For nutrition to improve and for food insecurity to recede, future agricultural production needs to rise faster than population growth, with sustainable intensification. That will result in the better and more effective use of land and water resources. Fewer people entail less competition for natural resources, lower levels of consumption and more countries exiting poverty (The Food and Agriculture Organisation of the United Nations and Earthscan, 2011). On the contrary, scientists still haven’t agreed upon the Earth’s carrying capacity, leaving a few available estimations valid and based on specific parameters. For example, if everyone on the planet lived like an average middle-class American, then the carrying capacity of the planet would be around 2 billion people (Whiting, 2018) Another way to mitigate the impact of overpopulation is to switch to clean energy sources such as solar, fully embrace the principles of circular economy and learn to manage water resources better. On a personal level, there are plenty of things to do, many habits to adjust to our daily life. Every day a greater amount of data about the implications of overpopulation to the planet and even people themselves emerge, boosting researchers to find new and more accurate solutions (The Overpopulation Project, 2020).



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[2], [18] United Nations Department of Economic and Social Affairs (2017). «World Population Projected To Reach 9.8 Billion In 2050, And 11.2 Billion In 2100» Available here.

[3], [14] LeBlanc, R.(2020). «The Environmental Impacts Of Overpopulation». The Balance Small Business. Available here.

[4], [24] Whiting, K. (2018). «David Attenborough: The Planet Can’t Cope With Overpopulation». World Economic Forum. Available here.

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[6] Chu, J., (2017). «Mathematics predicts a sixth mass extinction» MIT News. Available here.

[7], [8], [9], [10] Ray Nichols, M. (2020). «How Does Overpopulation Affect the Environment?». Schooled by Science. Available here.

[11] Kissinger, G., Herold, M. and De Sy, V., (2012). «Drivers Of Deforestation And Forest Degradation». Forest Carbon Partnership. Available here. 

[12] Arsenault, C., (2014) «Only 60 Years Of Farming Left If Soil Degradation Continues.»  Scientific American. Available here.

[13] Norwegian University of Science and Technology. (2018). «Clothing, Furniture Also To Blame For Ocean And Freshwater Pollution.» Eurekalert. Available here.

[15],[23] The Food and Agriculture Organisation of the United Nations and Earthscan. (2011). «THE STATE OF THE WORLD’S LAND AND WATER RESOURCES FOR FOOD AND AGRICULTURE Managing Systems At Risk. » Available here. 

[16] Bloom, D. (2020). «World Population To Surpass 7 Billion In 2011». Harvard, School of Public Health. Available here.

[17] (2020). «Causes And Consequences Of Overpopulation». Available here.

[19] Murtaugh, P. and G. Schlax, M., (2020). «Reproduction and the carbon legacies of individuals». Global Environmental Change. Available here.

[20],[21],[22] Center of Biological Diversity. (2020). Human Population Growth And Climate Change. Available here.

[25] The Overpopulation Project. (2020). «Solutions – The Overpopulation Project.» Available here.