Every population can reach their limit. This is not due to the availability of space but due to the availability of resources. The amount of resources affects the birth rate, death rate, immigration and emigration.
The formula for population growth is:
Population growth = (births + immigration) - (deaths + emigration)
Human population growth has increased for a variety of reasons. Basically we have developed the ability to survive and live in new habitats, increased the carrying capacity of the environment and removed a series of limiting factors.
Although the birth rate is declining, world population is increasing. This is due to the fact that people are living longer and a factor know as population momentum. What this means is that even though people are having fewer children on the average, there are more people having children to offset the birth rate. We presently are not involved in war and no diseases are devastating the world population. As in the past, people have to migrate to where there are more resources. These migrations may cause hardships on the areas they move into and conflicts may result. No one wants to see conflict and so it is very important that we find ways to stabilize our population and provide resources for all the world community.
Advances in technology can create new problems while solving problems for the Population. Since technology is a human generated action driven by human needs, the right procedures must be followed and tested fully before implementing the new techniques.
The Module Toxic waste: A teaching Simulation could be used at this time.
As stated earlier, resources are the main reasons for movement to and from an area. The greater the population, the greater the drain on our resources both renewable and nonrenewable. The length of time and energy required replenishing the renewable resources and the projected time before nonrenewable resources become depleted determine the need for alternatives.
Employment opportunities still tend to be a leading cause for increased urban population. This urbanization for jobs has created "spin-offs" such as increased pollution, unemployment, disease transmission, poverty and homelessness. Many cities are unable to provide the basic needs for all its populous and so deeds such as crime increase.
The higher the population density, the easier it is to transmit diseases even when adequate medical attention is available. However, most times people in poverty have limited access to health services, is illiterate, malnourished, and unemployed. These factors make it quite evident that the human factor will encourage an unhealthy life style.The human factor states that human condition = resources/population or H = R/P. It is quite evident that an increase in population means less resources for each individual. We can again relate to the "party" in the introduction to better understand this formula.
Another useful formula is used to describe the environmental impact the average U.S. places on the environment. The formula is I =PAT. This formula says that Impact Equals population size times affluence (individual consumption) times Technology and resulting pollution.
It has been calculated that the environmental impact by Americans is about 20 times greater than that of a Costa Rican and 70 times of a Bangladeshi. The U.S. contains about five percent of the world's total population but use 20% of all the metals, 25% of all the fossil fuels and 33% of all paper while producing 72% of the total toxic waste output in the world.
Does this mean we have an overpopulation problem? U.S. population growth is about 1% or roughly 2.7 million people. Of this number, 70% are due to natural increases and 30 % are from immigration. Because of the I = PAT formula, the impact for the 2.6 million U.S. people is equal to 54 million Costa Ricans and 190 million Bangladeshis.
Politically, the U.S. appears to encourage people to have more children. The income tax structure provide greater deductions for larger families and they are trying to give additional tax credits for college tuition which further reinforces this belief.
Technology increased unemployment, lower wages and increased population has caused a 50% increase in people living at the poverty level. In 1995, US workers earning below below-poverty wages reached 30%.
The United States has one of the highest natural population increases for industrialized countries with no relief in sight. Unless changes are made in the way we utilize our natural resources and treat our waste products, our quality of life will continue to decline.
There is a disagreement in the scientific community whether the human population has an upper limit. Some think that technological advances and improved food production and disease control will keep up with population growth.
Other scientists believe that at some point, the earth will no longer be able to provide enough food for everyone and the overpopulation of humans will also cause other life forms to become extinct.
In every population, there are certain factors that limit the population growth. These are called limiting factors. The two kinds of limiting factors are abiotic - nonliving factors and biotic - living factors. These two factors working together determine the carrying capacity of an ecosystem.
Under ideal conditions, populations increase to their maximum. However, we know that ideal conditions do not exist. Demographers make a population age structure graph to show population trends and use it to help make predictions about future population growth. This graph can show the age, sex and percent that each contributes to the population.
Extinction is a natural process that occurs as conditions on Earth change. Most species that have ever lived are now extinct. Many times the extinction of one organism leads to the evolution or extinction of another. Two types of extinction have and are taking place. One is called "background extinction" where there is a steady rate of species turnover. The larger and more complex organisms tend to have the higher extinction rate. Mass extinction is the result of a catastrophic event that caused large numbers of organisms to become extinct in a relatively short period of time. Five major extinctions have taken place during Earth history. These occurred during the Ordovician, Devonian, Permian, Triassic and Cretaceous times. These mass extinctions and smaller extinctions have had a profound effect on the history and diversity of life. Human activities have changed the present rate of extinction causing more mass extinction. New evidence shows that the change in physical environment is the most important factor with extinction and evolution. Man surely has the means and is diffinetly causing a change in the physical environment.