CHAPTER 7: The Human Population
Human Population Numbers
Economic Development, Consumption, and Stability
Current population around 7.2 billion people
Thomas Malthus
Malthusian View: population grows exponentially, while good supply grows linearly
Scientists who disagree believe that growing population leads to growth in intellect, leading to innovation
Factors that drive population growth
Changes in population size
Fertility
Life expectancy
Infant and child mortality
Aging and disease
Migration
Total Fertility Rate
Avg. # of children that each woman in a population will bear
Crude Birth Rate
Crude Death Rate
Rule of 70
the doubling time of a population: 70/growth rate
Global Population Growth Rate
(CBR-CDR)/10
Replacement Level Fertility
good predictor for resource consumption rates and environmental impacts
By increasing available prenatal care, a country can lower its infant mortality rate.
A larger number of older individuals can affect the crude death rate.
If life expectancy is high and infant mortality rate low, the country likely has a high level of available healthcare, food supply, drinking water, sanitation, and little pollution
These values can vary within a population, most likely related to socioeconomic status and varying degrees of access to adequate nutrition and healthcare
Disease
important regulator of human populations. HIV and AIDS are the biggest illnesses now, and have a significant effect on infant mortality, child mortality, population growth, and life expectancy.
Net Migration Rate
difference between immigration and emigration in a given year per 1,000 people
The movement of people can cause humanitarian and environmental health issues. The movement of people from undeveloped–––developed can increase the ecological footprint of those people, because they adopt the lifestyle and consumption habits of their new country
Age Structure Diagrams
Population Pyramid
Population momentum: continued population growth after growth reduction measures have been implemented. Occurs with relatively large #s of individuals at reproductive maturity in the population.
Theory of Demographic Transition: as a population moves from a subsistence economy to industrialization and increased affluence, it will undergo a predictable shift in population growth.This allows us to understand how countries influence the environment as they undergo growth and development
Phase 1: Slow Population Growth
Phase 2: Rapid Population Growth
Phase 3: Stable Population Growth
Phase 4: Declining Population Growth
nearly steady population; high birth rates; high death rates; short life expectancy
death rates decline; birth rates remain high; rapidly growing population; beginnings of modernization
stable population growth; CBR falls
population declines; high level of affluence and economic development; CBR below CDR
Family Planning
increasing education levels for women = decreasing fertility rates
IPAT Equation: used to estimate the impact of human lifestyles on the planet.
population x affluence x technology; population has straightforward effect, affluence as well. technology can both degrade and help the environment