W HY M IGHT THE W ORLD F ACE AN O VERPOPULATION P ROBLEM ? Malthus on overpopulation Declining birth rates World Health Threats

M ALTHUS ON O VERPOPULATION Thomas Malthus – English economist ( ) World’s rate of pop. increase was far outrunning the development of food supplies Population Growth vs. Food Supply An Essay of the Principle of Population (1798)…population increased geometrically, while food supply increased arithmetically Population growth would press against available resources in every country, unless “moral restraint” produced lower crude birth rates disease, famine, war or other disasters produced higher CDRs

N EO -M ALTHUSIANS Contemporary geographers and others looking again due to unprecedented rate of natural increase in LDCs Paint frightening picture where billions are engaged in a desperate search for food and fuel Many LDCs have expanded food production but they have more poor people than ever before

M ALTHUS ’ S C RITICS Esther Boserup and Julian Simon – larger population would stimulate economic growth and the production of food Friedrich Engels – Malthus was a capitalist World possesses sufficient resources to eliminate global hunger and poverty, if shared equally The world is better off economically with 6+ billion than with 1 billion because too few people can hinder economic development Some African leaders argue more people will result in greater power.

M ALTHUS T HEORY AND R EALITY Vaclav Smil – proved Malthus close to mark on food production, but off on population growth Problem is distribution of wealth rather than insufficient production of food Lower NIR during last 2 decades – same as 1980s

R EASONS FOR D ECLINING BR Natural increase declines due to lower birth rate or higher death rate 2 strategies for reducing BR: Reliance on economic development Women attend school, learn skills, gain control over lives, make informed choices Distribution of contraceptives LDC –demand > supply ¼ African women use – compared to 2/3 in other LDCs High BR reflect low status of women Opposition due to religious and political reasons LDC gov’t and international family planning orgs have limited funds

W ORLD H EALTH T HREATS Lower CBR have been responsible for declining NIR Some sub-Saharan countries lower NIR have resulted from higher CDRs, especially through diffusion of AIDS.

E PIDEMIOLOGIC T RANSITION S TAGES Stage 1 Pestilence and Famine Epidemiologist Abdel Omran (1971) Infectious and parasitic diseases principal causes of death Black Plague million Europeans (1/2 population) 5 other epidemics added to toll China – 13 million (1380)

E PIDEMIOLOGIC T RANSITION S TAGES Stage 2 Receding Pandemics Occurs over a wide geographic area Affects a very high proportion of population Cholera Industrial Revolution Dr. John Snow ( ) mapped 1854 London (Soho) deaths Overlaid victims map over map of water pump distribution Large % clustered around Broad Street pump Water and sewage systems eradicated cholera by late 1800s Reappeared century later in rapidly growing cities of LDC

E PIDEMIOLOGIC T RANSITION S TAGES Stage 3 Degenerative and human-created diseases Decrease of deaths from infectious diseases Increase in chronic diseases from old age Cardiovascular disease Heart attacks Cancer Effective vaccines responsible for sharp decline of infectious diseases Decline seen in countries moving from stage 2 to stage 3

E PIDEMIOLOGIC T RANSITION S TAGES Stage 4 S.Jay Olshansky and Brian Ault added this stage Delayed degenerative diseases Cardiovascular disease and cancer linger Life expectancy is extended through medical advances Stage 5 ?????? Reemergence of infectious and parasitic diseases Those thought to be eradicated return New ones emerge

R EASONS FOR S TAGE 5 E PIDEMIOLOGIC T RANSITION Evolution Microbes evolve and change in response to environmental pressures by developing resistance to drugs Malaria – almost eradicated due to DDT; returned after 1963 (2 million deaths worldwide) DDT resistant mosquitoes

R EASONS FOR S TAGE 5 E PIDEMIOLOGIC T RANSITION Poverty TB controlled in MDC like US, major cause of death in LDC Travel People carry diseases with them SARS (severe acute respiratory syndrome) China (11/2002) diffused to Canada and Vietnam

G LOBALIZATION AND EPIDEMICS SARS Shows risks and benefits Diffused within days Information also diffused rapidly around the world Quickly traced diffusion from Guangchou province in China to a Hong Kong hotel and then followed guests Fear that terrorists may be responsible Post 9/11 push for smallpox immunizations

G LOBALIZATION AND EPIDEMICS AIDS Most lethal epidemic in recent years, caused by HIV Impact strongly felt in sub-Saharan Africa 11 % of world population has 70 % of world’s HIV + population India – highest number of HIV+, then Caribbean countries (Haiti) CDR rose sharply during 1990s (mid teens to low twenties) Botswana and South Africa populations expected to decline by 2050