Core Geographic Themes: Population, Climate and Resources
How the core is examined
The core is compulsory content: population distribution and change, global climate vulnerability and resilience, and global resource consumption and security. Questions typically ask you to describe a pattern from data, explain the process behind it, then evaluate a response - so every theme needs mechanism plus a located example.
Core rules
- Population: rate of natural increase = CBR − CDR (per 1,000). Overall growth adds net migration. Total fertility rate is per woman, not per 1,000 people - never substitute it for the crude birth rate.
- Dependency ratio = (0–14 + 65+) ÷ (15–64) × 100. A wide-based pyramid signals high youth dependency, momentum for future growth and pressure on schools and jobs.
- Climate: vulnerability = exposure + sensitivity − adaptive capacity. Mitigation attacks the cause (emissions); adaptation manages the impact (sea walls, drought-resistant seed, early warning systems).
- Resources: security has four tests - availability, accessibility, affordability, acceptability. The water–food–energy nexus means a fix in one raises demand in another.
Worked example
Country X: CBR 34, CDR 9, net migration −4 per 1,000. RNI = 25 per 1,000 = 2.5%. Demographic growth = 21 per 1,000 = 2.1%. Doubling time ≈ 70 ÷ 2.1 ≈ 33 years. Reasoning: keep rates per 1,000, convert to a percentage before using the rule of 70, and include migration only in the growth rate, never in RNI. Interpretation: stage 2–3 of the transition, youthful pyramid, high child dependency, emigration slightly easing pressure.
Traps that cost marks
Describing the DTM as a law rather than a descriptive, originally European model. Swapping mitigation and adaptation. Quoting an ecological footprint in tonnes of CO2. Explaining a pyramid shape without naming the event behind a notch.