| IB ESS — PAPER 2 TOPIC FREQUENCY MATRIX (Old SL May 2019–2024 → Mapped to New 2026 Syllabus) |
| Based on old IB ESS SL Paper 2 topic patterns — mapped to new 2026 topic structure | ESS has no TZ split — one global exam | SL: HL-only rows greyed |
| ⚠ May 2026 = FIRST sitting of new syllabus. All NEW topics (flagged below) are predicted HIGH for first sitting. HL Lenses are CERTAIN for HL students. |
| # | Topic | Sub-topic / Concept | M19 | M20 | M21 | M22 | M23 | M24 | Freq | HL Lens? | May 2026 |
|---|
| TOPIC 1: FOUNDATIONS — Perspectives, Systems & Sustainability |
| 1.1 | Foundations | Systems thinking — transfers, transformations, feedback loops, system diagrams | ✔ | ✔ | ✔ | — | ✔ | ✔ | 5 | SL&HL | ⭐⭐⭐⭐⭐ |
| 1.2 | Foundations | Environmental value systems (EVS) — ecocentric, anthropocentric, technocentric | ✔ | — | ✔ | ✔ | — | ✔ | 4 | HL Ethics | ⭐⭐⭐⭐ |
| 1.3 | Foundations | Sustainability — natural capital, ecological footprint, carrying capacity | ✔ | ✔ | — | ✔ | ✔ | — | 4 | SL&HL | ⭐⭐⭐⭐ |
| 🔒 Topics 2–8 + May 2026 Predictions locked Ecosystems · Biodiversity · Climate Change · Human Systems · Resource Management · New HL Topics · Full prediction ratings Unlock Free → >TOPIC 2: ECOLOGY — Ecosystems & Ecological Processes |
| 2.1 | Ecology | Ecosystems — food chains/webs, trophic levels, energy flow, biomass pyramids | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | 6 | SL&HL | ⭐⭐⭐⭐⭐ CERTAIN |
| 2.2 | Ecology | Energy flow — NPP, GPP, trophic efficiency — calculate & explain | ✔ | ✔ | — | ✔ | ✔ | — | 4 | SL&HL | ⭐⭐⭐⭐ |
| 2.3 | Ecology | Nutrient cycles — carbon cycle, nitrogen cycle — draw system diagram + human impact | ✔ | — | ✔ | ✔ | — | ✔ | 4 | SL&HL | ⭐⭐⭐⭐⭐ |
| 2.4 | Ecology | Population ecology — S-curve, J-curve, carrying capacity, limiting factors | ✔ | ✔ | ✔ | — | ✔ | ✔ | 5 | SL&HL | ⭐⭐⭐⭐ |
| 2.5 | Ecology | Succession — primary, secondary; climax community; deflected succession | — | ✔ | ✔ | — | ✔ | — | 3 | SL&HL | ⭐⭐⭐ |
| 2.6 | Ecology | Biomes — distribution, climate, characteristics, NPP comparison | ✔ | — | ✔ | ✔ | — | ✔ | 4 | SL&HL | ⭐⭐⭐⭐ |
| 2.7 | Ecology | Biogeochemical cycles (detailed) — nitrogen cycle in full, phosphorus cycle HL only | — | — | — | — | — | — | 0 | HL only | NEW HL — CERTAIN |
| TOPIC 3: BIODIVERSITY & CONSERVATION |
| 3.1 | Biodiversity | Measuring biodiversity — species richness, Simpson's diversity index — calculate | ✔ | — | ✔ | — | ✔ | — | 3 | SL&HL | ⭐⭐⭐⭐ |
| 3.2 | Biodiversity | Threats to biodiversity — habitat loss, invasive species, climate change, overexploitation | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | 6 | SL&HL | ⭐⭐⭐⭐⭐ CERTAIN |
| 3.3 | Biodiversity | Conservation strategies — in-situ vs ex-situ, protected areas, CITES, rewilding | ✔ | — | ✔ | ✔ | — | ✔ | 4 | HL Law+Ethics | ⭐⭐⭐⭐ |
| 3.4 | Biodiversity | Species extinction — causes, consequences, keystone species, IUCN Red List | ✔ | ✔ | — | ✔ | ✔ | — | 4 | SL&HL | ⭐⭐⭐⭐ |
| TOPIC 4: WATER SYSTEMS & AQUATIC FOOD PRODUCTION |
| 4.1 | Water | Hydrological cycle — stores, flows, human impacts — draw & explain | ✔ | ✔ | — | ✔ | — | ✔ | 4 | SL&HL | ⭐⭐⭐⭐ |
| 4.2 | Water | Water pollution — eutrophication, BOD, sewage, agricultural runoff | ✔ | — | ✔ | ✔ | ✔ | — | 4 | SL&HL | ⭐⭐⭐⭐ |
| 4.4 | Water | Aquatic food production — fishing methods, aquaculture, sustainable fisheries management | ✔ | ✔ | — | — | ✔ | ✔ | 4 | HL Law+Econ | ⭐⭐⭐⭐ |
| TOPIC 5: LAND SYSTEMS & TERRESTRIAL FOOD PRODUCTION |
| 5.2 | Food Production | Food production systems — compare intensive vs organic vs sustainable agriculture | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | 6 | HL Econ+Ethics | ⭐⭐⭐⭐⭐ CERTAIN |
| 5.3 | Land / Soil | Land degradation — desertification, deforestation, salinisation, overgrazing | ✔ | — | ✔ | — | ✔ | ✔ | 4 | SL&HL | ⭐⭐⭐⭐ |
| 5.4 | Food Security | Food security — green revolution, GMOs, food miles, fair trade — evaluate | — | ✔ | ✔ | — | ✔ | — | 3 | HL Econ+Ethics | ⭐⭐⭐⭐ |
| TOPIC 6: ATMOSPHERE & CLIMATE CHANGE |
| 6.1 | Atmosphere | Atmospheric systems — greenhouse effect, albedo, energy balance — draw & explain | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | 6 | SL&HL | ⭐⭐⭐⭐⭐ CERTAIN |
| 6.2 | Climate Change | Climate change — causes, evidence, feedback loops, consequences — evaluate responses | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | 6 | HL Law+Econ | ⭐⭐⭐⭐⭐ CERTAIN |
| 6.5 | Energy | Energy production — fossil fuels vs renewables vs nuclear — evaluate sustainability | ✔ | ✔ | ✔ | ✔ | — | ✔ | 5 | HL Econ+Ethics | ⭐⭐⭐⭐⭐ |
| 6.4 | Air Pollution (HL) | Photochemical smog, acid rain — formation, impacts, management HL only | ✔ | — | ✔ | — | ✔ | — | 3 | HL only | ⭐⭐⭐⭐ HL |
| TOPIC 7: NATURAL RESOURCES, HUMAN POPULATIONS & URBAN SYSTEMS |
| 7.1 | Human Population | Human population — DTM, age-sex pyramids, ecological footprint, population policies | ✔ | ✔ | ✔ | — | ✔ | ✔ | 5 | SL&HL | ⭐⭐⭐⭐ |
| 7.4 | Urban Systems | Urbanisation, urban heat island, green infrastructure, smart cities — NEW 2026 | — | — | — | — | — | — | 0 | SL&HL | ⭐⭐⭐ NEW — HIGH |
| 7.5 | Env. Policy | International agreements — SDGs, IPCC, Paris Agreement, MEAs — evaluate | ✔ | ✔ | — | ✔ | ✔ | — | 4 | HL Law+Econ | ⭐⭐⭐⭐ |
| HL ONLY — THREE LENSES (NEW 2026): Environmental Law · Environmental Economics · Environmental Ethics |
| HL.1 | Env. Law (HL) | International environmental law — apply Paris, CBD, CITES, Ramsar to evaluate governance HL only | — | — | — | — | — | — | 0 | HL only | NEW HL — CERTAIN |
| HL.2 | Env. Economics (HL) | Ecosystem service valuation, natural capital, carbon markets, Polluter Pays HL only | — | — | — | — | — | — | 0 | HL only | NEW HL — CERTAIN |
| HL.3 | Env. Ethics (HL) | Ecocentrism, deep ecology, rights of nature, intrinsic value, duties to future generations HL only | — | — | — | — | — | — | 0 | HL only | NEW HL — CERTAIN |