ENVMS 101 Module 4 Notes: Demography

Flashcards covering key vocabulary, concepts, models, and historical context of human demography from ENVMS 101 Module 4 notes.

Demography

The study of various aspects of human populations; the human equivalent of population ecology.

Immigration

Movement into a region.

Human Population Growth Milestones

Reached 1 billion in the early 1800s, 2 billion in 1930, 3 billion within the next 30 years. Expected to reach 8.5 billion by 2030 and 9.7 billion by 2050.

World's Most Populous Countries

China and India (over 1.4 billion each), with the United States a distant third (approx. 330 million).

Formula for Population Growth

(Births - Deaths) + (Immigration - Emigration)

Factors Supporting Larger Populations

Advanced agricultural techniques, improved shipping, advances in medicine, better nutrition, and prenatal care (lowering infant mortality rates).

Doubling Time

The estimated time it would take a population to double, calculated by dividing 70 by the annual growth rate.

Total Fertility Rate (TFR)

The average number of children to which a woman will give birth over her reproductive lifetime.

Replacement Fertility

The TFR that allows a population to remain stable over time; for humans, this rate is 2.1 children per couple.

Key to Slowing Population Growth

Empowering women and couples to engage in family planning and expanding educational opportunities for women.

Age Structure

The relative number of individuals in each age class within a population, important for predicting future population dynamics.

Increasing Population (Age Structure)

The number of children far exceeds that of adults, often found in developing countries, potentially leading to instability.

Stable Population (Age Structure)

The number of individuals is similar among age classes, except for the oldest age groups.

Declining Population (Age Structure)

The number of young people is lower than that of older individuals, raising concerns about workforce and retirement programs.

Sex Ratio

The ratio of males to females in a population, naturally skewed slightly towards males (approx. 106 male infants for every 100 female infants).

Demographic Transition Model

A concept proposed by Frank Notestein to explain the declining death rates and birth rates that occur as nations industrialize, consisting of pre-industrial, transitional, industrial, and post-industrial stages.

Pre-Industrial Stage

Characterized by high death and birth rates due to widespread disease, minimal medical care, and unreliable food supplies, resulting in very slow population growth.

Transitional Stage

Industrialization leads to declining death rates (better sanitation, medical care, food), while birth rates remain high, causing rapid population growth.

Industrial Stage

Increased employment opportunities (especially for women) and access to birth control lead to falling birth rates, closing the gap with death rates and reducing population growth.

Post-Industrial Stage

Both birth and death rates have fallen to low and stable levels, causing population sizes to stabilize or decline slightly.

IPAT Model

Developed by Paul Ehrlich and John Holdren (1974), representing environmental impact (I) as a product of population (P), affluence (A), and technology (T): I = P × A × T.

Sensitivity (S)

An additional factor to the IPAT model, denoting how sensitive a given environment is to human pressures (I = P × A × T × S).

Ecological Footprint

The amount of Earth’s productive surface area required to provide the resources a person or population consumes and to dispose of the waste produced.

Carrying Capacity

The maximum population size that the environment can sustain indefinitely, limited by factors such as disease, water, living space, and food.

Ecological Debt

The situation where humans are using resources and creating pollution faster than the Earth can accommodate.