Module 7: Human Population
Week of Tue, Oct 13 · module closes Mon, Oct 19 · 130 points
Take Meerk's quiz for Module 7
This module's items
- Case Study #530 pts
- Unit 2 Exam100 pts
Exact due times are in Canvas. Late assignments are not accepted without a valid, documented reason. Make-up exams are not given.
Know these cold
- Global human population reached 8 billion in 2022. Growth was slow for most of history, then accelerated sharply after the Industrial Revolution due to improved food, medicine, and sanitation.
- The demographic transition model (DTM) describes four stages of population change as countries industrialize: Stage 1 (high birth + high death), Stage 2 (high birth + falling death → population boom), Stage 3 (falling birth + low death), Stage 4 (low birth + low death → stability).
- Total fertility rate (TFR): average number of children per woman over her lifetime. Replacement-level TFR is 2.1 in developed nations (slightly higher in nations with higher child mortality).
- An age structure diagram shows the proportion of a population in each age group. A wide base = young, growing population. A narrow base = aging, potentially shrinking population.
- Rule of 70: divide 70 by the annual growth rate (%) to estimate the doubling time in years. A 1% growth rate means a population doubles in ~70 years.
- The IPAT equation: I = P × A × T. Environmental Impact = Population × Affluence (per-capita consumption) × Technology (environmental impact per unit of consumption).
- Urbanization: more than half of the world's population now lives in cities. Cities concentrate resource consumption but can also reduce per-capita impact through density and shared infrastructure.
- Population growth is not uniform — high-income countries near Stage 4, low-income countries in Stage 2–3. Most future growth is projected in sub-Saharan Africa and South Asia.
Discussion and forum — how to show up
Netiquette from the syllabus: address ideas, not people. Complete sentences, correct spelling. Personal matters go to email, never the board.
Meerk's quiz — open the Module 7 gate
10 questions, no time limit. 85% on your first attempt in a 24-hour window opens the gate. Retakes inside the window are practice — they help you learn, they don't count. Work alone; the point is to know it, not to have seen it.
Dinner Table Question
Ask at home: The US has a TFR below replacement (about 1.6), yet our population keeps growing. What explains that — and what are the environmental consequences?
En español: La TFR de EE. UU. está por debajo del nivel de reemplazo (alrededor de 1.6), pero nuestra población sigue creciendo. ¿Qué lo explica — y cuáles son las consecuencias ambientales?