The Impact of Population Growth on The Environment

If someone from space were to look at the Earth 500 years ago, they would see something very different than they would today. As the centuries have passed, more and more people are populating the Earth and it brings up a question that is still currently debated. Is this growth in population bad for the environment? The current world population stands at, ‘6.7 billion people and the 2006 revision of the United Nations World Population Prospects presents a medium variant projection by 2050 of 9.2 billion people and still growing’ (De Sherbinin 2007). There are many effects that come with this population growth, some positive and some negative. From a positive perspective, with every newborn human, there is another set of working hands to contribute to society. On the other hand, with each body put on Earth, resources become more scarce, destruction of animal habitats occur to provide housing, and the climate changes due to the release of greenhouse gases from activities humans are performing. Much research has been done on this particular topic and I am going to analyze both sides of the debate, looking into several of the different aspects of why population growth affects all of us.

There are many different sides on this subject and I am going to analyze two of them whose opinions are described extensively in the article "How Many is Too Many" by Charles Mann. On one side there are the Cassandras, ‘who believe that continued population growth at the current rate will inevitably lead to catastrophe. On the other are the Pollyannas, who believe that humanity faces problems but has a good shot at coming out okay in the end’ (Mann 1993). Cassandras are typically biologists and Pollyannas are typically economists, and these fields of study contribute to their views on the population and how it affects the environment. For example, the Cassandras believe in the concept of ‘ecology’ and that the world is reaching its ‘carrying capacity’ and soon will not be able to sustain human life. On the other hand, the Pollyannas reject this idea because they have no proof of it happening in the past and they instead believe that as the population grows, the economy will grow, allowing the Earth to continue support for human life (Mann 1993). This causes the Cassandras to, ‘look at each new birth as the arrival on the planet of another hungry mouth’ and Pollyannas to, ‘point out that along with each new mouth comes a pair of hands’ (Mann 1993). The Cassandras are thinking more logically because they are thinking about what could happen to the Earth if population keeps growing as fast as it is now and they are acknowledging the consequences that could arise because of it. They have many supporting scenarios that raise the need for action against overpopulation. Contrastingly, the Pollyannas believe that nothing bad is going to happen because it never has. They are very optimistic and believe that if humankind runs out of a resource, they can invent a new one and continue surviving. Although this has been successful thus far, the Earth is growing faster than ever and there is going to come to a point where humans have used up all they can and nature is not going to support them anymore.

In 1798 there was a book published anonymously that caused an uproar in the debate of population growth. Although it was not the first, it was one of the most influential and the most talked about. The book was An Essay on the Principle of Population, whose author would later be revealed as Thomas Robert Malthus. In this book, Malthus revealed his predictions about the world and argued that population would grow faster than food, causing the world to go through famine. In An Essay on the Principle of Population, it states, ‘the power of population is indefinitely greater than the power in the Earth to produce subsistence for man’ (Malthus 1798), meaning as the population continues to increase, the world will not be able to support its inhabitants. Malthus believed that humankind should be aware of the fact that the world was going to lead to disaster if the booming population were to continue. Karl Marx disagreed with Malthus’ prediction and felt that he was not taking all future inventions into consideration. According to Marx, scientific and technological progress would increase alongside population growth, causing them to balance out and the world to remain in harmony. Since Malthus predicted that the world was going to end soon and that it could not survive much longer when he wrote the book in 1798 and the world is still alive now, Marx was proved right. However, now the world is becoming more vulnerable and is in danger because it is growing even faster than Malthus had predicted and science and nature itself do not seem as if it will be able to continue to provide for humankind.

One of the issues that are arising and making population growth an issue is food production. In an article called "Billions and Billions", Kolbert explains, ‘the other uncertainty is the world’s ability to provide for all these additional people. As many people, including Bill Gates, have pointed out, just to keep per-capita food production constant in the coming decades will require a second "green revolution" ‘(2011). It seems as if at this rate, the Earth is not going to be able to provide for the abundance of people that inhabit it. Also, since many people are in denial of how overpopulation is affecting the world we live in and how it is affecting us, we are not being precautious with our resources. For example, almonds. ‘Each almond requires 1.1 gallons of water to produce’ (Hamblin 2014) and California was still continuing to produce almonds even when they were in a drought. Also, during the first ‘Green Revolution’, we used up almost all of the phosphorus that was used to enhance fertilizers and now it is being exhausted. Next, it could be oil, water, or arable land (Kolbert 2011) because individuals are treating these natural resources as a finite resource which they are not. Past events have proven that humankind finds a resource that benefits them and overuse it until it becomes on the verge of going extinct. ‘As populations increase and economies expand, natural resources must be depleted; prices will rise, and humanity -- especially the poor and future generations at all income levels -- will suffer as a result’ (Sagoff 1997). If we can stop this depletion, limit the growth of population and make the economy and resource availability more stable, this tragedy can be put to an end.

In addition to economic complications, there is also human to human consequences caused by overpopulation. With so many people populating the Earth, new diseases and germs with inevitably arise with humans having no defense, because it is something they have never been exposed to before. It is said that: …each day 110,000 people die from starvation, malnutrition, and poverty-related diseases; 500 million people worldwide have malaria; 1.2 billion people live in absolute poverty; 1.5 billion people have no access to a safe and healthy water supply; 5 million people most of them children under the age of five die every year from preventable water-borne diseases; between 150,000 and 350,000 Americans die prematurely each year because of air pollution (Miller, 1996, p. 601).

These are statistics from 1996 and the population has grown immensely even in that short period of time, making the number of deaths more severe. Because of population growth, more and more people are being exposed to malaria and starvation and malnutrition, simply because there are too many people inhabiting Earth to contain these types of diseases and stop them from spreading. It is also estimated that ‘by the end of the decade another 100 million people will be infected by HIV’ (Mann 1993) which, you would think would cause population growth to decrease, but that is not the case, because it is growing too rapidly to be affected. Fertility rate also plays a big factor in why population growth is happening so quickly. 1.9 billion more people have arrived on Earth that have left and history has shown that humans replace themselves as time goes on. Even if the fertility rate was low, it would still cause the population to grow, because too many people have arrived and are continuing to reproduce (Mann 1993). A theory that analyzes this epidemic in detail is Malthus’. He believed that humankind was trapped by the intersections of two things, one being its population rate. From Malthus’ observations, he concluded that the world was and is experiencing, ‘geometrical growth, namely 1,2,4,8,16. It only needs 32 doublings like this to lead from an original couple to the present world population of over six billion persons’ (Macfarlane). This supports the argument that the population is increasing as well as replacing itself, causing a doubling effect. This increases the human to human consequences that occur throughout the world and it is making life less sustainable.

Some people, on the other hand, believe population growth is not something environmentalists should be worried about and actually believe it to be something positive and beneficial. These types of people do not look at each individual as a mouth to feed and one who spreads disease, but rather another set of helping hands and someone to contribute to society. People who believe in this were typically called ‘Cornucopians’, which are people who argue that human beings are a resource themselves. Julian Simon, who was around from 1932 until 1998, started this ‘Cornucopian Theory’ and gave people information that leads them to believe population growth was a good thing and not something to be worried about (Murphy 2006). Another piece of information that supports the people in favor of population growth is the four-stage model of population growth. This model predicts that in the first stage, birth, death and infant rates are all high and life expectancy is short, causing population growth to be rather low. In stage two, population growth rises as infant mortality rates and death rates drop. This is when the population grows rapidly because people are still having big families, but they are now living longer. In stage three, birth rates decline and death rates decrease while life expectancy continues to increase. Lastly, in stage four, birth and death rates are low, life-expectancy high, causing society to enter a phase of population stability (Caldwell and Caldwell 2006). Based off of this information, it would seem as if population growth is under control and that it is benefiting society, but that is not the case.

Another reason why environmentalists should be opposed to population growth is climate change. In the article, Six Degrees: Our Future on a Hotter Planet, Lynas states, ‘since the beginning of the Industrial Revolution, concentrations of the principal greenhouse gas, carbon dioxide (CO2), have risen by a third’ (2008). Carbon dioxide is released into the air in many different ways including, but not exclusive to air pollution, habitat destruction, light pollution, noise pollution, and trash. All of these contributing factors increase as the population of Earth increases which is why climate change is becoming such a big issue. As more people inhabit Earth, more cars are on the roads releasing more smog into the air, more houses and cities are being built which increases the use of electricity and noise. More people means more trash because poverty and homelessness are also increasing and the world simply does not have enough resources for everyone. People believe that global warming is not as severe as people make it seem because the human race is continuing to release so much CO2 gas and very little is happening, but the reason for that is that the increase in temperatures has about a 50-year delay. The future temperature rises that are in our future will be a result of the carbon emissions we have released in the past. The Earth has already increased temperatures by about .8 degrees Celsius (Lynas 2008) and that is coming from a period where the Earth did not have nearly as many people or technological advancements it does now, so the rise from now on is expected to be even faster. Results from the February 2017 IPPC Fourth Assessment Report (AR4) stated, ‘For the lowest emission scenario, where global greenhouse gas emissions dip sharply, warming by 2100 could be as low as 1.1 degrees Celsius, whereas for the highest emissions scenario, global warming could reach 6.4 degrees Celsius’ (Lynas 2008). Even if the entire world reduced their greenhouse gas emissions, there is still going to be a rise in temperature because we cannot change what we released in the past. If the population continues to grow, lowering gas emissions becomes less and less realistic. This warming of the Earth is bad for many reasons, one major reason is the revival of old diseases. It is said that ‘there are now, trapped in Arctic ice, diseases that have not circulated the air for millions of years- in some cases, since before humans were around to encounter them’ (Wallace-Wells 2017). If the Earth’s temperature rises enough, this ice will melt and release these diseases that our bodies and immune systems do not know how to defend. Climate change also affects food production, because it can depress the amount of food that can be grown on farmland because temperatures are too high.

Lastly, there is the effect of population growth on the environment itself. In an article by Robert Chapman, he states, ‘overpopulation, although difficult to define precisely, produces serious environmental problems. It might be the case that no one ever died from overpopulation, but certainly many have experienced a diminished quality of life’ (1999, p. 81). Due to there being an overly abundant amount of people on the Earth, resources are becoming more scarce and the environment is receiving the consequences of that. Animal habitats are being destroyed, species are going extinct, the Great Barrier Reef is dying and rainforests are being destroyed. The main concern here is that the land area on Earth is fixed and natural resources are finite (despite popular belief) causing this exponential population growth to be unsustainable (Bell and Odom 2013). Looking at the United States alone, which compromises only 5 percent of the world’s population, is using 25 percent of the world’s resources. They also produce the most trash and pollution, contributing to global warming and scarcity. ‘In energy consumption alone, the typical American uses as much energy as three Japanese, six Mexicans, 15 Chinese or 531 Ethiopians’ (Weber 1990). Statistics like these are what make population growth such a bad thing and why is it destroying the planet we live in. To truly understand the concept of limited resources, take a look at coal. When coal is unburned and in its natural state, it has an amount of integrity that is based on how much energy or works it can produce; Georgescu-Roegen would call this a state of low entropy. Once the coal is burned, this integrity is lost and goes into a state of high entropy. During this process from low to high entropy, the amount of energy in the system is the same quantity-wise but has lowered in quality. When the coal was burned, energy was released that can no longer be used. ‘As populations increase so does entropy. In a system of infinite resources this would not be a problem; in a finite one, like our own, it can be a tragedy’ (Georgescu-Roegen 1987). The world continues to use up all its resources, thinking that something else will arise that it can use, but these resources are not infinite. They will run out and we will not have any substitutions to survive. The more people the world allows to inhabit, the faster this will happen and the sooner we will run out of our resources.

Clearly, population growth has an effect on many things. These include food shortage, declining resources, disease and climate change. Each of these is events and factors that will affect the human population negatively and make life on Earth less pleasurable and maybe even uninhabitable. With the population growing exponentially, the way it will change the daily lives of the human race will be fatal. Not only does population growth affect humans, but it also affects animals and the environment. With more people living on the Earth, more houses are being built and animal habitats are being destroyed. Species are going extinct; fewer trees and rainforests are thriving. All of these are contributions that humans need to survive, but at this rate will not be around in the coming future. Most importantly, the environment itself is being affected, because the animals, the trees and humans are all part of it. If each of those factors is causing negative events to happen on Earth, the environment is going to pay the price too. The Earth is not finite and is not full of unlimited resources. If population growth continues to happen, there will come a point where the Earth is going to decide it is too much and life as we know it will no longer exist. In my opinion, population growth is causing the Earth more harm than good and environmentalists should be opposed to it.