Environmental Systems and Societies · Topic 8: Human populations and urban systems
ES8.1 — Human populations
Environmental Systems and Societies · SL / HL · syllabus-mapped notes
Inputs, outputs and population rates
Births and immigration as inputs, deaths and emigration as outputs, and the rates that quantify a population: crude rates, total fertility rate, life expectancy, doubling time and natural increase.
Predicting future global growth
The rapid growth curve of the human population and how UN models predict its future through three fertility-linked scenarios, with the uncertainty behind them.
Managing growth: direct and indirect policies
Direct anti-natalist, pro-natalist and migration policies, plus indirect economic, social, health and development policies, with named examples.
Population structure: age-sex pyramids and the DTM
Modelling population composition with age-sex pyramids and the five stages of the demographic transition model.
HL: Population pressure, dependency and momentum
How rapid growth stresses Earth's systems, and how pyramids reveal the dependency ratio and population momentum.
HL: Comparing countries and environmental migration
Explaining structure and growth using two countries at different DTM stages, and migration driven by climate change and land degradation.