IB ESS Topic 8: Human populations and urban systems
2 ready-made review sets for this topic, 24 questions in all, marked SL or HL, to play as a class game on the projector. Free to host, and students join with a code.
Topic 8 covers human populations (birth, death and fertility rates, doubling time, age-sex pyramids, the demographic transition model and population policies), urban systems, from urbanization and suburbanization to urban sprawl, and urban air pollution: primary pollutants, fine particulates such as PM2.5, and acid rain. At higher level it adds dependency ratios, population momentum and environmental migration, ecological urban planning and green architecture, and photochemical smog, tropospheric ozone and temperature inversions.
8.1 Human populations
8.2 Urban systems and urban planning
8.3 Urban air pollution
Where students slip
Crude birth and death rates are per 1,000 people a year, so the natural increase rate as a percentage is (CBR − CDR) ÷ 10.
Doubling time is about 70 divided by the growth rate in percent: a population growing at 2% a year doubles in about 35 years.
HL A population can keep growing for decades after fertility falls to replacement level, because so many people are still young. That is population momentum.
HL Primary pollutants come straight from a source; secondary pollutants, such as tropospheric ozone, form in the air from primary ones.
HL In a temperature inversion, warm air sits above cooler air near the ground and traps pollution at street level.
The sets
Play this set opens the set in splycr, where you can read every question and host it for your class straight away. Hosting needs no account, and students join with the code on the board. A free account lets you copy a set and edit it.
The questions come from the Biology by Bradford flashcard bank. Each one plays as multiple choice, and the wrong options are other answers from the same set.
ESS has had a higher level course since the guide first assessed in 2026. Sets marked SL suit every ESS student, because higher level students study the standard level content too. Sets marked HL cover the additional higher level material in topics 2 to 8; Topic 1 has none, so its sets are all SL. The three HL lenses (environmental law, economics and ethics) have no sets yet.
Topic 8: Human Populations
15 questionsSL
Number of years a population takes to grow to twice its size at its current growth rate, approximately 70 ÷ growth rate (%)?
Answer: Doubling time
Model of how a country's birth and death rates, and so its population growth, change through five stages over time as it develops?
Answer: Demographic transition model (DTM)
Pollutants emitted directly from a source (e.g. CO and NO from vehicle exhausts, SO₂ from burning coal)?
Topic 8 is often taught last. In Cryo the questions are how students reload in a frozen arena, so a review before the exam feels like a break while everyone keeps answering. Up to 20 players.
For a class with laptops: a 3D zombie arena where an infected student answers a question from the set correctly to get back in. Up to 40 players, with a keyboard and mouse.
