NRES 287 — Week 2: Population Growth & Scarcity

Population Growth Rate (current trends)

• An increase in population by 2 billion went from taking 200,000 yrs to now about 25 yrs

• The rate of population growth has slowed since 1960 (but the number of people is still growing)

• Countries with large percentage of people under 15 are growing rapidly

• Slow decline is usually manageable whereas rapid declines lead to economic problems

• Ex. Countries with rapidly declining populations: Japan, Germany, Italy, Bulgaria, Hungary, Romania, Portugal

Age Structure

Proportion of males vs females in young, middle, or older age groups within a population.

• countries with large percentage of people under 15 are growing rapidly

Malthusian

• A population perspective

• population growth is the main driver of environmental degradation because it creates resource scarcity

• Population grows exponentially — 2, 4, 8, 16, 32

• Resources grow linearly — 2, 4, 6, 8, 10

• Hypothesized demographic trends: oscillations will occur due to scarcity & resource conflict — preventative checks will lower birth rate & positive checks will occur to increase death rate

• Policy suggestions: solutions are with the control of individuals & helping the poor is counter productive — welfare programs just facilitate population growth

• Implications: past & present attempts to affect fertility rates — Uzbekistan 2000s & China’s former one-child policy

Neo-Malthusian

• a population perspective

• Population growth is important in environmental impacts, but affluence & technology mediate these effects

• Similar views to Malthusian about overpopulation

• Shifted more towards concern about environmental impacts

• Greater emphasis on limiting population growth through birth control

• Ehrlich (1968) tried to account for different factors with the publication of a controversial book — The Population Bomb

• The I=PAT equation

• More people more mouths; food production will not keep up with demand

The I=PAT Equation

• neo-Malthusian

• Population growth is an important factor in environmental degradation, but affluence & technology mediate these effects

• I = impact on the environment

• P = population (density)

• A = affluence — measured by produced goods & services (e.g., GDP); wealthier people tend to consume more resources

• T = technology (energy consumption per capita) — technology can either reduce environmental impacts (Ehrlich, 1974) or increase them (Commoner, 1988)

• Critiques: overly simplistic but useful starting point for estimations, overlooks political context & governance, what is the role of development? — Kuznets curve

• Missing: development

Environmental Kuznets Curve

• neo-Malthusian

• Critique of I=PAT

• The environmental Kuznets curve is based on the assumption that development will have increasing impact on the environment

• Once a threshold of affluence is reached, economic transition & regulations lead to a decrease in environmental impacts

• Fits some issues: air pollution & deforestation

• Does not solve others: energy use & biodiversity loss

Access & Capability

• a population perspective

• Amartya Sen

• Population growth is not the main problem for resource scarcity

• Resource scarcity -related problems are caused by access & capability, not availability

• Analyzed historical famines (1981) & showed limited associations with food shortages

• Problem was not lack of resources, but lack of access to resources

• Still possible that we could face scarcity of resources in the future

• Critiques: even with fair access, Earth has finite resources (land, water, minerals); access-based solutions may not prevent absolute shortages when ecological carrying capacity is exceeded — ex. Groundwater depletion in parts of sub-Saharan Africa cannot be solved by redistribution alone

Summary pt.1

• multiple theories around population growth

• Mediating factors can help to explain growth patterns — roles of technology, affluence & other factors, as well as access; the planet’s carrying capacity can potentially shift through innovation & intensification; Kuznet’s curve; access more than population control

• Carry capacity & ecological footprints can be used to think about the impacts of individuals & populations

More developed countries

• Industrialized nations with high average income per person

• 17% of the world’s population

• Use 70% of the world’s resources

Less developed countries

• have higher growth rates but fewer emissions

• LDCs in Africa, Asia, & Latin America account for 80% of the world’s population

• Use about 30% of world’s natural resources

Cornucopian

• A population perspective

• Ester Boserup

• Population growth provides a resource for innovation to deal with resource scarcity

• “Cornucopian” population theorists see population as a resource rather than a problem

• There are sufficient resources to sustain populations

• When resources are scarce, people will innovate

• More people means more brains & hands working to solve problems

• Farmers will change practices if population increases & more food is needed — food depends on innovation, not the reverse

• Population & innovation: Green Revolution provides evidence; induced intensification of agricultural techniques invented during this time led to greater crop yields

• Critiques: informed scale of processes such as food production; some innovations increase agricultural food supply but damage other ecosystems — irrigation = soil degradation; more food may be produced than is needed, but it is not evenly distributed — food waste

• More people more ideas; food production is sufficient

Equal Growth Rate

Equal number of births & deaths, therefore no net change in population

• growth trends are moving towards zero growth rate in some countries

Population decline

• recent population projections indicate that 23 countries will see their population halve by 2100

• Nearly all (183/195) countries will have a fertility rate below the replacement level

The Demographic Transition Model

• a population perspective

• Population growth is the result of underdevelopment

• Suggests that “development” is the cause of declining population growth rates

• In other words, population growth is not the cause of underdevelopment, but the result

• Stages:

  • Stage 1: high death rate, high brith rate to compensate, stable population, “pre-industrial” stage; no countries are currently classified as stage 1

  • Stage 2: rapid decrease in death rate — due to improvements in overall health, pediatric care, lower infant mortality; birth rates remain stable, rapid population growth

  • Stage 3: rapid decrease in death rate; death rates continue falling; birth rates decrease, generally due to increase in women’s status & education, & access to contraception; Population growth continues but slows

  • Stage 4: both birth & death rates are low & stable; population remains stable, brighter increasing nor decreasing; USA is considered stage 4

  • Stage 5: birth rates continue to decline, death rates may begin to rise due to aging populations, population decline

Critiques:

• assumes a linear trajectory of development based on a particular context

• Does not account for non-economic factors that may affect population growth

What influences population change?

• population change = (births + immigration) — (deaths + emigration)

• Replacement-level fertility rate

• Total fertility rate

Replacement-level Fertility Rate

Average number of children a couple must bear to replace themselves

• about 2.1

• Higher than 2 because some children die before reaching reproductive years

Total Fertility Rate

The average number of children born to the women of childbearing age in a population.

Factors that affect fertility

1. Lack of importance of children as a part of the labor force

2. Cost of raising & education children

3. Availability of social support infrastructure (e.g., healthcare, pension systems)

4. Education + employment for women

5. Average age at marriage

6. Availability of birth control

7. Religious beliefs, traditions, & cultural norms

Women’s rights & fertility

• around the world, women’s rights, education, & literacy rates are linked to lower fertility rates

• Lower fertility rates are also associated with women’s access to reproductive health care & ability to make reproductive decisions

Should environmental concerns be addressed via population control?

• there is potential violence of population-centered thinking

• Targets the poor & women rather than systemic causes of degradation