Upload
coral-newton
View
215
Download
0
Tags:
Embed Size (px)
Citation preview
OVERPOPULATION
KNOWING WHEN TO SAY WHEN…
An English economist who argued that the world’s rate of population increase was outrunning development food supplies.
His claim was that population increases geometrically but food supply increases arithmetically.
He predicted that population growth would outstrip food resources unless “moral restraint” lowered CBRs or disease, famine, war or other disasters raised CDRs.
The point of crisis is when an area exceeds its CARRYING CAPACITY (the maximum number of a species that an environment can sustain indefinitely)
THOMAS MALTHUS(1766-1834)
“The fundamental problem [facing the planet today is that] there are too many people. For the planet’s
sake, I hope we have bird flu or some other thing that will reduce the population, because otherwise we’re
doomed.” –Dr. Susan Blackmore, nueroscientist
Claim Malthus’s prediction is more pressing that ever because: a) He failed to predict the medical revolution and its
ushering LDCs into stage 2, thus the gap between population and resources is wider in some countries than Malthus anticipated
b) World population is outstripping other resources, not just food:
WaterEnergyFarmlandClean Air
The prediction: increased wars and violence in the future.
NEOMALTHUSIANS
Claim that Malthus was a moron
Claim that the world’s resources are not fixed but expanding
Are possibilists and claim that humans can choose positive courses of action to expand food supply and other resources
Man can develop new technologies, use existing resources more efficiently and substitute new resources for scarce ones
Boserup and Kuznets: larger population is good… stimulates the economy and leads to more food production. More populaiton, more customers and more thinkers/inventors.
Julian Simon: Yeah, what they said.
Marxists: the problem isn’t production/population, the problem is distribution (unfair society)
Various leaders: more population is good because greater numbers = greater power.
ANTI-MALTHUSIANS
World as a whole has plenty of food, but some areas do face shortages
Malthus was pretty accurate about food production and its arithmetic growth
However production has grown faster than anticipated recently due to better growing techniques, high yield seeds, expansion of cultivated land, fertilizer technology, etc.
And food production has grown has outpaced NIR since 1950
Population did not quadruple between 1950 and 2000 as Malthus expected because cultural, technological and economic changes pushed more countries into stages 3 and 4 of the DT faster than he predicted
Population has been growing at a slower pace since the 1970s (down to 1.3 from 1.8 for the world)
The question is WHY??
REALITY
AMMUNITIONFOR BOTH
SIDES
MALTHUS IS STILL RELEVANT MALTHUS IS IRRELEVANT
THE EVIDENCE
THE REASONS THE REASONS
THE EVIDENCE
A. The population is rising/ has grown as Malthus predicted
A. Limited use of contraception. Political policies, economic decisions, cultural beliefs that support population growth. Country is in Stage 2 and/or early Stage 3 of the Demographic Transition.
B. Food supply has increased, but it has not kept up with population increase or has grown as predicted by Malthus.
C. There are other limiting factors on population in addition to food.
B. Countries: fail to adopt agricultural innovation, b/c political policies, economic decisions, cultural beliefs. Convert farmland for urban use. Have practices that create environmental degradation (desertification, overgrazing, clear cutting, soil erosion, waterpollution). Convert of food crops to cash crops. Have high fuel prices that slow growth of food production and distribution.
C. Because of resource overuse and/or environmental degradation, countries exceed their carrying capacity
A. Pop growth not geometric/ or as Malthus predicted
B. Food supply has grown faster than Malthus predicted / the carrying capacity of most country’s land has increased
C. Better modern ability to preserve food and/or distribute food to areas of need
A. Expanded use of contraception. Countries have political policies, economic decisions, cultural beliefs that limit population growth. Countiry is in late Stages 3, 4, and/or 5 (declining birth rate) of the Demographic Transiition.
B. Countries have: efficient farming (industrial tech). Green revolution techniques. Expanded Agricultural land. Humans with the ability to problem solve
C. Improvements in methods of transportation. Improvements in food preservation
The NIR can decline for only two reasons:
A HIGHER death rate (CDR)
Which is a bad choice…In movies and in reality
A LOWER birth rate (CBR)
Which is what is happening…except for a few countries in Africa
DECLININGNIR
Economic Development Approach (Pro-Natal)
Family Planning Approach (Anti-Natal)
Pro-natalism assigns a positive value to birth and espouses its free practice. This approach allows families free choice while also creating an environment where couples choose to have fewer babies.
Emphasizes reliance on economic development to push the social changes of stage 3
Wealthier communities have more to spend on health care, sanitation, education and programs that end up lowering the CBR
If more women are in school and attend school longer, and if more women pursue careers, then they delay having children and have fewer children
If more people are urban centered and work in industry, they have fewer children
With improved health care and sanitation, IMR’s drop and since more infants survive, women have fewer children
Anti-Natalism assigns a negative value to childbirth when childbirth contributes to overpopulation. There are more and less aggressive methods.
On the whole these methods seek to bring advances of the medical revolution, primarily birth control, to LDCs to lower CBRs in them.
Less Aggressive Method: Voluntary family planning through distribution of birth control. Great success in Bangladesh (went from 6% to 58% usage in 25 years), Colombia, Morocco, Thailand.
75% of women in Asia and 66% in Latin America employ birth control, only 25% Africa.
More Aggressive Methods:
China’s One Child Policy
Forced Sterilization (Nazi Germany)
LOWERING THE CBR
Lower CBRs have reduced the NIR in most places, but some Sub-Saharan African countries have seen higher CDRs.
The CDR usually grows through the spread of disease.
HIGHER CDR
SPREAD OFINFECTIOUS
DISEASE
A model that identifies the distinct causes of death in each stage of the demographic transition
The Demographic Transition
Stage 1 Stage 3 Stage 4Stage 2
•CBR is high, variable•CDR is high, variable•NIR in flux near zero•Population flat, low
•CBR is high, variable•CDR drops steeply•NIR increases steeply•Population explodes
•CBR drops steadily•CDR shallows drop•NIR drops steeply•Pop increase shallow
•CBR & CDR meet low and level•NIR near zero•Population flat, high
The Epidemiologic Transition
Stage of pestilence and famine
•Infectious and parasitic diseases cause death
•Malthus’s natural checks
Stage of receding pandemics
•Improved sanitation, nutrition, medicine in MDCs
•Medical Revolution in LDCs
Stage of degenerative and human created
diseases
•Decrease infectious disease death
•More age illnesses: cancer, heart disease
Stage of delayed degenerative disease
•Degeneratice diseases linger
•Medical technology extends lifespan overall
EPIDEMIOLOGICTRANSITION
Demographic Transition Epidemiologic Transition
CBR drops below CBR and begins period of irreversible
population decline
Some diseases reemerge and other new ones appear, the CDR begins to rise
Caused by evolution, poverty, improved spread through travel
Stage 5 Stage of reemergence of infectious and parasitic diseases
POSSIBLESTAGE 5
Regional Patterns Breast cancer rates arehigher in richer nations, wherewomen give birth later in lifeand have fewer children. Colorectal cancer, linkedto diets with more meat andprocessed foods in affluentnations, is less deadly whencaught early. Cervical cancer kills morewomen in countries wherethe human papilloma virus iscommon and screening rare. Liver cancer is linked to thehepatitis B and C viruses, moreprevalent in nations like China,South Korea, and Mongolia.
GRAPHIC: OLIVER UBERTI, NGM STAFF; SOURCE: GLOBOCAN, INTERNATIONAL AGENCY FOR RESEARCH ON CANCER
Where is cancer deadliest? The answer depends on regional differencesin lifestyle, diet, and health care. Worldwide,lung cancer claims the most lives.
1. P
RED
ICT
THE
RATE
S
2. P
RED
ICT
THE
RATE
S
3. P
RED
ICT
THE
RATE
S
4. P
RED
ICT
THE
RATE
S
Some of the below cancers would be considered stage 2, others stage three and four. Try to predict their regions based on
their descriptions
WORLD CANCER RATES