EFFECT OF OVER POPULATION

Overpopulation is a generally undesirable condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth, or smaller geographical areas such as countries. Overpopulation can result from an increase in births, a decline in mortality rates, an increase in immigration, or an unsustainable biome and depletion of resources. It is possible for very sparsely populated areas to be overpopulated if the area has a meager or non-existent capability to sustain life (e.g. a desert).

The population has been growing continuously since the end of the Black Death, around the year 1400,[citation needed] although the most significant increase has been in the last 50 years, mainly due to medical advancements and increases in agricultural productivity. Although the rate of population growth has been declining since the 1980s, the United Nations has expressed concern on continued excessive population growth in sub-Saharan Africa. As of April 25, 2012 the world human population is estimated to be 7.009 billion by the United States Census Bureau, and over 7 billion by the United Nations. Most estimates for the carrying capacity of the Earth are between 4 billion and 16 billion. Depending on which estimate is used, human overpopulation may or may not have already occurred. Nevertheless, the rapid recent increase in human population is causing some concern. The population is expected to reach between 8 and 10.5 billion between the year 2040 and 2050. In May 2011, the United Nations increased the medium variant projections to 9.3 billion for 2050 and 10.1 billion for 2100.

The recent rapid increase in human population over the past two centuries has raised concerns that the planet may not be able to sustain present or larger numbers of inhabitants. Steve Jones, head of the biology department at University College London, has said, "Humans are 10,000 times more common than we should be". The InterAcademy Panel Statement on Population Growth has stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming, and pollution, are aggravated by the population expansion. Other problems associated with overpopulation include the increased demand for resources such as fresh water and food, starvation and malnutrition, consumption of natural resources faster than the rate of regeneration (such as fossil fuels), and a decrease in living conditions. However, some believe that waste and over-consumption, especially by wealthy nations, is putting more strain on the environment than overpopulation.

Some problems associated with human overpopulation

1.          Depletion of natural resources, especially fossil fuels. World energy consumption & predictions, 1970–2025.

2.          Increased levels of air pollution, water pollution, soil contamination and noise pollution. Once a country has industrialized and become wealthy, a combination of government regulation and technological innovation causes pollution to decline substantially, even as the population continues to grow.

3.          Deforestation and loss of ecosystems that sustain global atmospheric oxygen and carbon dioxide balance; about eight million hectares of forest are lost each year.

4.          Changes in atmospheric composition and consequent global warming.

5.          Irreversible loss of arable land and increases in desertification.Deforestation and desertification can be reversed by adopting property rights, and this policy is successful even while the human population continues to grow.

6.          Mass species extinctions from reduced habitat in tropical forests due to slash-and-burn techniques that sometimes are practiced by shifting cultivators, especially in countries with rapidly expanding rural populations; present extinction rates may be as high as 140,000 species lost per year. As of February 2011, the IUCN Red List lists a total of 801 animal species having gone extinct during recorded human history.

7.          High infant and child mortality. High rates of infant mortality are caused by poverty. Rich countries with high population densities have low rates of infant mortality.

8.          Intensive factory farming to support large populations. It results in human threats including the evolution and spread of antibiotic resistant bacteria diseases, excessive air and water pollution, and new viruses that infect humans.

9.          Increased chance of the emergence of new epidemics and pandemics.For many environmental and social reasons, including overcrowded living conditions, malnutrition and inadequate, inaccessible, or non-existent health care, the poor are more likely to be exposed to infectious diseases.

10.      Starvation, malnutrition or poor diet with ill health and diet-deficiency diseases (e.g. rickets). However, rich countries with high population densities do not have famine.

11.      Poverty coupled with inflation in some regions and a resulting low level of capital formation. Poverty and inflation are aggravated by bad government and bad economic policies. Many countries with high population densities have eliminated absolute poverty and keep their inflation rates very low.

12.      Low life expectancy in countries with fastest growing populations.

13.      Unhygienic living conditions for many based upon water resource depletion, discharge of raw sewage and solid waste disposal. However, this problem can be reduced with the adoption of sewers. For example, after Karachi, Pakistan installed sewers, its infant mortality rate fell substantially.

14.      Elevated crime rate due to drug cartels and increased theft by people stealing resources to survive.

15.      Conflict over scarce resources and crowding, leading to increased levels of warfare.

16.      Less personal freedom and more restrictive laws. Laws regulate interactions between humans. Law "serves as a primary social mediator of relations between people." The higher the population density, the more frequent such interactions become, and thus there develops a need for more laws and/or more restrictive laws to regulate these interactions. It was even speculated by Aldous Huxley in 1958 that democracy is threatened due to overpopulation, and could give rise to totalitarian style governments.

Effects of Overpopulation on the Environment

The human population has been increasing at an extremely high rate in the last century and unfortunately, not much has been done to slow down this process. Undoubtedly, overpopulation is a global issue. It is global because it pertains to all of humanity, but global also means that it affects the whole world, i.e. the environment. Almost all human activities impact negatively the environment in one form or another, and as human population expands, the damaging effects on the environment multiply. Here are some of the most imminent environmental problems that results from human population growth:

    1. Water supply. Water is one of the basic elements of live, and it is needed to preserve the balance of every ecosystem. It cools down and cleanses the environment and is used by plants and animals to carry out vital functions. As human population increases, so does the consumption of water. In the past fifty years, the per capita availability of fresh water has decreased by one third.* Fresh water supply is a problem in most of the developing countries, especially those located in arid climates such as in Africa, South America and Asia. In some African countries, fresh water needs to be carried daily from sources more than two hours walking distance. Water supply is an issue in urban areas as well. In Beijing, the water table falls down with as much as two meters annually.

    2. Water pollution. The problem with water is not only overconsumption, but also pollution. "More than 95% of urban sewage in developing countries is discharged untreated into the nearest waterway or field."* The main contributors to water pollution are factories and open mines, discarding waste water with heavy metals, toxic substances and solid waste, which are virtually impossible to purify. The situation is even worse when it comes to ocean exploitation and pollution. Overfishing changes the balance in coastal ecosystems and decreases fish populations. Sometimes it might even lead to extinction of certain marine species. Overfishing also damages coral reefs, because it allows algae to overgrow them. It turns out that the ocean is "the ultimate garbage dump "* because eventually all of the sewage, sediment from forest clearing, fertilizer and pesticide run-off flow into it. It is important to preserve the ocean, not only because it is an important source of food, but also because it plays a major role in climate regulation. The circulation of cold and warm water protects the earth from extreme temperature fluctuations. In addition, oceans absorbs between 30 and 40% of the CO2 given off as a result of human activity, thus keeping global warming at stake.

    3. Soil Degradation. Population growth results increases the demand for food production. Since the arable land in many of the overpopulated regions is limited, farmers begin to cultivate dry, hilly, nutrient-poor areas that are not very suitable for farming. Exploiting such lands makes them easily susceptible to erosion and loss of nutrients. For example, in search for farmland in Indonesia, peasants have been planting their crops on steep slopes. As a result, almost one half of Java's land is now in danger of erosion.* Globally, the statistics are even more frightening. It is estimated that 1.2 billion hectares of land, approximately the size of Europe, U.S. and Mexico combined, have lost much of their agricultural output capability in the last 50 years.

    4.Deforestation. The search for more farmland causes other damaging agricultural practices such as slash-and-burn cultivation. Basically, a forest area is burned and converted into pasture, but due to poor soils, it looses its productivity in about three years.* This initiates a vicious circle which results in the deforestation of large areas, mostly in tropical regions. Deforestation is also caused by the use of wood as fuel, since 9 out of 10 African households use wood for cooking and heating. This is the reason why Ghana lost almost a third of its dense forest from 1938 to 1980. In addition, the building of roads and the expansion of residential areas have contributed to the loss of primary forest.

    5. Loss of biodiversity. All of the previously described effects of overpopulation on the environment lead to the destruction of the natural habitat of many wildlife species. The natural flora and fauna have been under constant pressure to adapt to a quickly changing environment. Since they have been unable to do so, they have been displaced from their natural ecological niche. The constant clearing of the Amazon forest has had devastating effect on many rare tropical species. It has been estimated that 10% of the species in the region have become extinct.

All of the above environmental issues clearly indicate that the natural assets that humans take for granted are in grave danger. Most of the damage on the environment caused by human expansion is long-lasting and in some cases permanent. There is no doubt that the human population will continue increasing and the condition of the environment will exacerbate. Therefore, only a sustainable approach toward conserving what currently exists as natural resources could counteract the detrimental effects of overpopulation on the natural world.

REFERENCE

1.      "Global food crisis looms as climate change and population growth strip fertile land". Guardian.co.uk. 31 August 2007.

2.      "BBC News – Population seven billion: UN sets out challenges". BBC. 26 October 2011. http://www.bbc.co.uk/news/world-15459643. Retrieved 30 November 2011.

3.      "U.S. Census Bureau – World POPClock Projection". http://www.census.gov/population/popclockworld.html. Retrieved 2011-10-27.

4.      "Population seven billion: UN sets out challenges". BBC. 2011-10-26. http://www.bbc.co.uk/news/world-15459643. Retrieved 2011-10-27.

5.      "World's 'seven billionth baby' is born". The Guardian. 2011-10-31. http://www.guardian.co.uk/world/2011/oct/31/seven-billionth-baby-born-philippines?intcmp=122. Retrieved 2011-10-31.

6.      "7 billion people is a 'serious challenge'". UPI, 31 October 2011. Retrieved 2011-11-09.

7.      "World Population Clock – Worldometers". Worldometers.info. http://www.worldometers.info/population/. Retrieved 2010-08-01.

8.      ^ "International Data Base (IDB) – World Population". Census.gov. 28 June 2010. http://www.census.gov/ipc/www/idb/worldpopinfo.php. Retrieved 2010-08-01.

9.      ^ "World Population Prospects:The 2008 Revision". Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. June 2009. http://www.un.org/esa/population/publications/popnews/Newsltr_87.pdf.