Population refers to the number of people inhabiting a geographic area. The area can be a district, town, city, state, country, or a continent. It can also refer to a subgroup of people living in area and have a common characteristic. The three main components of a population are; fertility, mortality, and migration (Smith et al., 27). Fertility is the ability of a person to reproduce. In terms of populations, fertility is expressed as a measure of birth rate. When there are minimum or no efforts to regulate the size of a family, there can be rapid population growth if a large portion of the population is in the fertile stage. Birth rates differ across the world with some countries having an average family size of 8.0 and others having low averages of 3.0. The average birth rates and family sizes are low in developed countries and tend to be high in the underdeveloped and developing nations (Smith et al., 28).
Mortality as the second component of population is responsible for the reduction of populations. In any given population, the rates of mortality are usually highest in old age and infancy. Diseases are also responsible for mortality while can reduce the number of young men in a population. Countries with improved health care systems and welfare have high life expectancy rates which results in increased population among the upper age groups (Smith et al., 28). Migration is the last component of population and it refers to the movement or flow of people across geographical regions. Emigration is one form of migration and describes the departure from own country to another while immigration is entering into a new country. Migration occurs due to reasons such as wars, natural disasters, or when people seeking for opportunities (Smith et al., 29).
Demographic transition describes the change of a population over time and usually occurs in four phases. The first phase occurs in a pre-industrial society where the birth rates and death rates are high and have no balance. The population growth is low because of constraints in resources. The second phase is characterized by low death rates and high birth rates because of improvements in nutrition and sanitation (Wilson, 33). The third stage comprises of a reduction in birth rates because of changes such as education of women, urbanization, access to contraception, and status change among women. There is also a low death rate which signifies a slow population growth. During the fourth phase, the birth rates and death rates are low and almost equal, and the population growth is at zero (Wilson, 33).
One of the problems of overpopulation is that it leads to the scarcity and conflicts over resources such as food and water. Also, overpopulation has a negative impact on the environment and natural resources (Bodley, 289). Due to the increased demand for resources, people tend to exploit the available resources beyond the recommended levels. They overfish in rivers and exploit land for agricultural purposes. Deforestation also occurs as people seek for arable land, expansion of residential areas, and wood for fuel and industrial purposes. The increased human activities cause air, land, and water pollution and loss of diversity. Overpopulation leads to high poverty and unemployment levels, lawlessness, and unequal education (RRC). The problem of overpopulation can be addressed through policy changes to avail funds to people for them to start businesses. There is need for better sex education and increased access to contraceptives. Also, quality education should be availed to all children.
- Bodley, John H. Anthropology and Contemporary Human Problems. Lanham, MD: AltaMira Press, 2012. Print.
- RRC,. “Overpopulation Causes, Effects & Solutions | Renewable Resources Co”. Renewable Resources Coalition. N.p., 2017. Web. 12 Apr. 2017.
- Smith, Stanley K, Jeff Tayman, and David A. Swanson. A Practioner’s Guide to State and Local Population Projections. , 2013. Internet resource.
- Wilson, G A. Multifunctional Agriculture: A Transition Theory Perspective. Wallingford: CABI, 2007. Internet resource.