The two types of population growth of any species are exponential growth and logistic population growth (Simon, Reece and Dickey, 2010). Exponential population growth is defined as the rate of which a population grows constantly over a period of time resultant of continuous birth rate and ideal environmental conditions. In other words, the quality and quantity of resources is available at an overall higher standard, (Otherwise, 2012).
The second type of population growth is logistic population growth. Most environments do not have unlimited resources. Limiting factors such as “carrying capacity” come into play.
Carrying capacity is an environment that sustains a maximum population size (Simon, Reece and Dickey, 2010). When the population size begins to reach carrying capacity, there is a decrease in growth rate. When the population size is at its maximum for carrying capacity, it yields a zero growth rate (Simon, Reece and Dickey, 2010). As the population grows it can cause a number of serious problems such as food-scarcity, overcrowding, poverty, increased consumption, excess waste, and exploitation of natural resources such as land, water, fossil fuels, and vegetation.
The combined effects of population growth, consumption, overuse, wastage and misuse of resources will strain the capacity of the earth to sustain life (Simon, Reece and Dickey, 2010). Human population exceeding its natural resources will limit access to basic needs such as adequate housing from overcrowded areas as lack of space will become evident. Building materials require resources such as timber from forests which results in deforestation. Means of transport require more consumption of fossil fuels, thus pollution of air, land and water result from greenhouse gas emissions.
Scarcity of food and potable water will incur as more mouths to feed require agricultural production, also a result in deforestation, thus the need for increased water usage, and the application of pesticides and fertilizers that make the soil infertile and water scarce and non-potable. Generation of waste increase will require critical attention to proper waste management in order to prevent the spread of disease or epidemics (Simon, Reece and Dickey, 2010).
Population will rise most rapidly in places least able to handle it, developing nations where hunger, political instability and environmental degradation are already pervasive (Otherwise, 2012). Massive efforts are in great need to keep social and economic conditions from deteriorating further. When the number in population exceeds the natural resources available to sustain it, there will be a profound effect on the overall quality of life and the degree of human suffering on Earth.