Overpopulation Why the world might face an overpopulation problem What are three problems that can be caused by overpopulation? Is your “Ping” country overpopulated? Why?

Why does global population growth matter? Global starvation War Disease Lower quality of life Lowered life expectancy

Malthus Thomas Malthus ( ) – English economist who first argued that the world’s rate of population increase was far outrunning the development of food supplies. His view remains influential today. An Essay on the Principle of Population  Population increases geometrically  Food supply increases arithmetically Relationship between people and food  Today = 1 person, 1 unit of food  In 25 years = 2 persons, 2 units of food  In 50 years = 4 persons, 3 units of food  In 75 years = 8 persons, 4 units of food  In 100 years = 16 persons, 5 units of food

Beyond Malthus Neo-Malthusians Argue that two characteristics of recent population growth make Malthus’s thesis more frightening in today’s world. 1. Rapid population growth in poor countries caused by the transfer of medical technology, without the transfer of wealth or resources. 2. World population growth is outstripping total resources, not just food production. Malthus’s Critics Criticism aimed at both the population growth and resource depletion elements of the theory -  Resources – Fixed or not fixed/ possibilism  Population growth could stimulate production  Distribution could be better handled  More people = more brain power  More people = more power

Declining Birth Rates Malthus Theory and Reality Malthus predicted population would grow faster than food production, but food production actually expanded faster than population in the second half of the twentieth century. Better growing techniques Higher-yielding seeds Cultivation of more land/more arable land

Reasons for Declining Birth Rates Natural Increase Rate (NIR) can decline for only two reasons –  Lower birth rates  Higher death rates Reasons for declining birth rates  Economic development  Distribution of contraceptives

World Health Threats Natural Increase Rate – Lower birth rates or higher death rates? Epidemiology – The branch of medical science concerned with incidence, distribution, and control of diseases that affect large numbers of people. Epidemiologic Transition – Focuses on distinctive causes of death in each stage of the demographic transition.  Originally formulated by Abdel Omran in 1971

Epidemiologic Transition Stages 1 and 2 Stage 1/Black Plague – The stage of pestilence and famine Stage 2/Cholera – The stage of receding pandemics Pandemic – A disease that occurs over a wide geographical area, and affects a very high proportion of the population.

Epidemiologic Transition Stages 3 and 4 Stage 3 – The stage of degenerative and human-created diseases  Decline of infectious diseases  Heart disease  Cancer Stage 4 – The stage of delayed degenerative diseases  Medical advances

Epidemiologic Transition Stage 5 Stage 5 – The stage of the reemergence of infectious and parasitic diseases 3 reasons of explanation 1. Evolution 2. Poverty 3. Improved Travel