Population Growth Theories
Definition of Population Growth: • Population growth is change in population over time or the change in the number of individuals in a population per unit time. • Population Growth Rate is the rate at which the number of individuals in a population increases.
Definition of Population Growth: • The population growth rate has increased exponentially since humans first landed on the earth millions of years ago.
Definition of Population Growth: • The main problem with having too high of a population growth rate is that people are multiplying so quickly that there will not be enough resources on our planet to serve the people.
Four Basic Theories: • Cornucopian • Bogue • Malthus • Catton
Frank J Tipler:Creator of the Cornucopian Theory • Wrote the book “The Physics of Immortality” • Claims to have proven of the existence of life after death called the “Omega Point”
Cornucopian Definition of a Cornucopian: A cornucopian Is someone who believes that continued progress and provision of material items for mankind can be met by advances in technology.
Cornucopian • They believe that there is enough matter and energy on the Earth to support the peaking growth of the population which is estimated to be about nine million in 2050. Looking further into the future they believe that outer-space will give humanity almost unlimited room for growth. • There is no historical evidence that society will run out of resources.
Bogue • Optimistic • Theory of demographic regulation • Over time, society naturally limits or increases its population • Believes strongly in the “baby boom” theory • Believes there should be limits to the immigration laws • Industrial revolution dramatically increased Earth’s carrying capacity which caused a dramatic increase in birth rate • China’s one child law
Malthus • Has a pessimistic view towards the future of population growth • He predicted a scenario in which the earth will eventually run out of its natural resources and that the planets agriculture will be eventually outstripped by the growth of population. • This scenario is called the “Malthusian Catastrophe”
Malthus • He based this scenario on the fact that the earth’s population grows exponentially when the earth’s resources and agriculture grows linearly. Therefore eventually there will be too many people on the earth compared to our resources. • He used many mathematical equations to help him prove his scenario. • Key Points: • Population level is severely limited by subsistence • When the means of subsistence increases, population increases • Population pressures stimulate increases in productivity
William Catton:Creator of the Catton Theory • Wrote a book on his theory called “Overshoot: The Ecological Basis of Evolutionary Change” • Came up with the idea of the “Overshoot” in population
Catton • Is an expansion on the Malthus view • Phantom Carrying Capacity: is when the population is using non-renewable resources that while they sustain the current generation, will not be enough for the next to survive. • This is directly related to the Overshoot theory.
Catton • An overshoot condition occurs when the population growth rate exceeds the planets carrying capacity. At this point, the population will start to die out and eventually even out with the carrying capacity again. • The biggest problem with this situation is that the actual carrying capacity will be significantly decreased due to the planets environmental damage.
References • htttp://www.wikipedia.org • Global Connections Textbook (2003) • http://greatchange.org. • http://www.ucmp.berkeley.edu