Causes And Effects Of Global Overpopulation


According to the World Population Prospects: The 2017 Revision, “the current world population of 7.6 billion is expected to reach 9.8 billion in 2050”, published by the United Nations June 2017. With exponential growth in human population over recent centuries, the same occurrence has not taken precedence for the earth’s natural resources. Meaning, that which is needed to support and sustain a thriving global populace, like freshwater, food, energy, and other necessities, is at risk of exhaustion and therefore unable to fulfil demands. This reality has caused great concern in the scientific community and some world organisations alike. It is believed that the planet will soon reach its threshold where it can no longer sustain the ever-growing needs of its inhabitants. Many scientists have referred to this threshold as earth’s carrying capacity and is estimated at 9 to 10 billion people. As we know from the United Nations, this figure is projected for the year 2050 and beyond. Currently, there has been no collective effort by world leaders to address this calamity, that is overpopulation. Thus, further increasing the severity of the issue.

Causes of Overpopulation

In the 4.6 billion years of earth’s existence, modern humans (homo-sapiens) have only roamed the earth for about 200,000 years, specifically the continent of Africa. After 100,000 years or so they ventured out of the continent, becoming the first explorers. Some settled along the way, but as time passed others continued migrating across the globe, in the end, forming colonies in India, Southeast Asia and Australia, the Middle East, south-central Asia, later Europe and Asia, then finally North America. However, the population remained low, at approximately less than 1 million people. Though, with the onset of farming, earliest evidence pointing to about 23,000 years ago, they started having significant growth and by the year AD 1 world population had reached approximately 170 million people. Between then and the 17th century many events occurred attributing to the population’s growth like conquests, crusades, European exploration, the Atlantic slave trade, and colonialization of the Americas. This brought world population up to about 780 million people.

Then came the industrial revolution and modern medicine, exacerbating growth, hitting 1 billion people by the year 1804. This growth rapidly continued as the 20th century brought world war 1 & 2, the green revolution, and the information age. Before the industrial revolution, overpopulation was due largely in part by migration, since then there’s been the mechanising of society. Although revolutionary, as it skyrocketed productivity across all fields allowing for mass production of food, clothes and fundamentally anything can could be patented. This innovation helped stabilise society since for humans could now grow food far exceeding what was needed at the time, transport and store for longer periods without rotting. Eventually, this led to overproduction, over consumption and high waste; all the while not allowing for the replenishment of resources at the same rate. Subsequently, the industrial revolution also aided in birthing modern medicine. Vaccines, drugs, advanced medical practices, and a multitude of others resulted from modern medicine, this increased fertility but lowered mortality rates. Therefore, the population’s health improved, mortality decreased while birth rates stayed high, ultimately adding to the rampant growth in population.

Today, most of the growth occur in developing nations that lack the resources and expertise of strong governance to help transition their nations out of such a volatile stage. These countries are plagued with corruption, with some leaders driving them to the verge of collapse. The impacts of this include but aren’t limited to, disproportionate distribution of wealth and a lack of funding in education. It is believed that the lack of education of women in family planning, the use of contraceptives and accessibility to contraception is one of the main reasons for the rapid growth in developing nations. However, educating women generally lowers fertility rates, as educated women have greater opportunities than non-educated women and having children will come as a price in terms of opportunity costs. This of course largely affects those in poorer communities, many of whom lack the finances to attend educational institutions as they tend not to be in these areas.

Effects of Overpopulation

1. Loss of Freshwater

According to the Global Water Crisis report, by the United Nations University Institute for Water, Environment and Health, 70% of the planet is covered by water, with only 2.5% accounting for freshwater. However, 70% of freshwater is trapped in glaciers and ice caps, leaving a remainder of 30% which is distributed among land surface water (rivers, lakes, or wetlands) and groundwater reserves. Furthermore, high levels of contamination and lack of accessibility to these reserves, less than 1% of the world’s freshwater is readily available for direct human use. Based on their projections, it is expected that by the year 2050 over 40% of the world’s population will live in severely water-stressed river basins. Evidence of this would be that since 1960, there has been a 55% global decrease in available freshwater per capita. Thus, with increasing population growth, demands for freshwater will continue to soar. As freshwater becomes scarce, governments may resort to annexing territories rich in this natural resource which may then create conflicts with other nations looking to do the same. Agriculture and manufacturing will be under threat as well, globally 70% of all freshwater is consumed by the agriculture industry whereas 20% is for industry, leaving 10% for domestic use. This may also have adverse effects on economies as countries that rely heavily on revenue from exportation of goods will have difficulty sustaining itself and its people while trying to meet global demands.

Species Extinction and Habitat Loss

With the depletion of freshwater resources, ecosystems found in those territories are under threat of extinction. These include many freshwater fish species, plants, bacteria, and other microorganisms. Another case would be land-use activity, as civilizations grew the need for a built environment and energy sources became more pronounced. Since all these energy sources are found in the natural environment, land is allocated for the extraction of minerals, fossil fuels, timber, etc. This however infringes on the inhabitants of these spaces, leaving many animal species without a home and driving many toward extinction. Similarly, the many plant life affected as well was detrimental. Overfishing is another example of this, the desire to meet high demands through illegal or unregulated fishing has gravely affected the totally fish stock and other oceanic species.

Lower Life Expectancy in the Developing Nations

Developing nations account for majority of the population surges in the forthcoming years, according to a Harvard study, “over the next 40 years, nearly 97% of 2.3 billion projected increase will be in less developed nations”. These nations are already credited with having some of the highest pollution rates due to lacklustre environmental laws, are overcrowded, have accessibility problems to freshwater and nutritious foods and low-quality health-care infrastructure. Conditions like these, contributes to increased malnutrition, leading to increased human disease and death. Civil unrest also arises from these circumstances. Militias form in response to their leaders failing in their duties in attempt to restore order. However, this process is long, mortality rates soar but so do birth rates.

Depletion of Natural Resources

Human consumption is another consequence of population growth, more finite resources like fossil fuels, freshwater, and land are depleting rapidly. With the current trajectory, it’s believed that the planet’s supply of natural resources has far been surpassed by the demands of its human inhabitants. This has economic impacts as well, without alternatives, the value of these resources will explode. Those in poorer countries will have difficulty producing food, minerals, fuel, and other resources. Already predisposed to poor infrastructure that could generate revenue many of these nations will falter when shortages start occurring. Their citizens usually can only support themselves in the most basic way, thus do not have disposable income to pay taxes with. Additionally, with little money in their treasuries, the result of overpopulation in this case means they’ll be unable to provide social welfare, pensions, or basic health care service for an expanding population.

Increased Global Warming and Climate Change

Rapid increase in the carbon footprint in recent decades has been proven to be directly related to human activity. Greenhouse gases in the atmosphere have been largely credited to the industrialisation of the globe since the industrial revolution. It is widespread knowledge that this gas build-up in the atmosphere has had adverse effects on weather patterns and the climate. This includes the continued rise in the earth’s temperature affecting aqua-systems like reefs; rapid melting of the ice-caps and glaciers bringing forth sea level rise with animal species facing extinction, polar bears being one of them; increased storm frequency and volatility; and a multitude of others. These effects can be catastrophic, is costly to rectify and some are irreversible. As population growth continues, more resources will be needed to repair damaged infrastructure and reverse the effects to damaged ecosystems, which could have been used in development of other areas.

11 February 2020
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