IB Environmental Systems and Societies

Topic 1: Foundation

Topic 2: Ecology

2.1 Individuals, populations, communities, and ecosystems

2.2 Energy and biomass in ecosystems

2.3 Biogeochemical cycles

2.4 Climate and biomes

2.5 Zonation, succession and change

Topic 3: Biodiversity and conservation

Topic 6: Atmosphere and climate change

Topic 7: Natural resources

Topic 8: Human populations and urban systems

Concept/IB ESS/SL/Topic 2: Ecology/2.3 Biogeochemical cycles

2.3 Biogeochemical cycles

Syllabus: First assessment 2026
Topic: 2.3
Level: SL

What you’ll learn

11 learning objectives

Choose one objective for a focused lesson, or study the complete topic.

2.3 Biogeochemical cycles