| # | Topic | Sub-topic / Concept |
M19 | M20 | M21 |
M22 | M23 | M24 |
Freq | HL Lens? | May 2026 |
| TOPIC 2: ECOLOGY (continued) |
| 2.3 | Ecology | Nutrient cycles β carbon cycle, nitrogen cycle β draw system diagram + human impact | β | β | β | β | β | β | 4 | SL&HL | βββββ |
| 2.4 | Ecology | Population ecology β S-curve, J-curve, carrying capacity, limiting factors | β | β | β | β | β | β | 5 | SL&HL | ββββ |
| 2.5 | Ecology | Succession β primary, secondary; climax community; deflected succession | β | β | β | β | β | β | 3 | SL&HL | βββ |
| 2.6 | Ecology | Biomes β distribution, climate, characteristics, NPP comparison | β | β | β | β | β | β | 4 | SL&HL | ββββ |
| 2.7 | Ecology | Biogeochemical cycles (detailed) β nitrogen cycle in full, phosphorus cycle HL only | β | β | β | β | β | β | 0 | HL only | NEW HL β CERTAIN |
| TOPIC 3: BIODIVERSITY & CONSERVATION |
| 3.1 | Biodiversity | Measuring biodiversity β species richness, Simpson’s diversity index β calculate | β | β | β | β | β | β | 3 | SL&HL | ββββ |
| 3.2 | Biodiversity | Threats to biodiversity β habitat loss, invasive species, climate change, overexploitation | β | β | β | β | β | β | 6 | SL&HL | βββββ CERTAIN |
| 3.3 | Biodiversity | Conservation strategies β in-situ vs ex-situ, protected areas, CITES, rewilding | β | β | β | β | β | β | 4 | HL Law+Ethics | ββββ |
| 3.4 | Biodiversity | Species extinction β causes, consequences, keystone species, IUCN Red List | β | β | β | β | β | β | 4 | SL&HL | ββββ |
| TOPIC 4: WATER SYSTEMS & AQUATIC FOOD PRODUCTION |
| 4.1 | Water | Hydrological cycle β stores, flows, human impacts β draw & explain | β | β | β | β | β | β | 4 | SL&HL | ββββ |
| 4.2 | Water | Water pollution β eutrophication, BOD, sewage, agricultural runoff | β | β | β | β | β | β | 4 | SL&HL | ββββ |
| 4.4 | Water | Aquatic food production β fishing methods, aquaculture, sustainable fisheries management | β | β | β | β | β | β | 4 | HL Law+Econ | ββββ |
| TOPIC 5: LAND SYSTEMS & TERRESTRIAL FOOD PRODUCTION |
| 5.2 | Food Production | Food production systems β compare intensive vs organic vs sustainable agriculture | β | β | β | β | β | β | 6 | HL Econ+Ethics | βββββ CERTAIN |
| 5.3 | Land / Soil | Land degradation β desertification, deforestation, salinisation, overgrazing | β | β | β | β | β | β | 4 | SL&HL | ββββ |
| 5.4 | Food Security | Food security β green revolution, GMOs, food miles, fair trade β evaluate | β | β | β | β | β | β | 3 | HL Econ+Ethics | ββββ |
| TOPIC 6: ATMOSPHERE & CLIMATE CHANGE |
| 6.1 | Atmosphere | Atmospheric systems β greenhouse effect, albedo, energy balance β draw & explain | β | β | β | β | β | β | 6 | SL&HL | βββββ CERTAIN |
| 6.2 | Climate Change | Climate change β causes, evidence, feedback loops, consequences β evaluate responses | β | β | β | β | β | β | 6 | HL Law+Econ | βββββ CERTAIN |
| 6.5 | Energy | Energy production β fossil fuels vs renewables vs nuclear β evaluate sustainability | β | β | β | β | β | β | 5 | HL Econ+Ethics | βββββ |
| 6.4 | Air Pollution (HL) | Photochemical smog, acid rain β formation, impacts, management HL only | β | β | β | β | β | β | 3 | HL only | ββββ HL |
| TOPIC 7: NATURAL RESOURCES, HUMAN POPULATIONS & URBAN SYSTEMS |
| 7.1 | Human Population | Human population β DTM, age-sex pyramids, ecological footprint, population policies | β | β | β | β | β | β | 5 | SL&HL | ββββ |
| 7.4 | Urban Systems | Urbanisation, urban heat island, green infrastructure, smart cities β NEW 2026 | β | β | β | β | β | β | 0 | SL&HL | βββ NEW β HIGH |
| 7.5 | Env. Policy | International agreements β SDGs, IPCC, Paris Agreement, MEAs β evaluate | β | β | β | β | β | β | 4 | HL Law+Econ | ββββ |
| HL ONLY β THREE LENSES (NEW 2026): Environmental Law Β· Environmental Economics Β· Environmental Ethics |
| HL.1 | Env. Law (HL) | International environmental law β apply Paris, CBD, CITES, Ramsar to evaluate governance HL only | β | β | β | β | β | β | 0 | HL only | NEW HL β CERTAIN |
| HL.2 | Env. Economics (HL) | Ecosystem service valuation, natural capital, carbon markets, Polluter Pays HL only | β | β | β | β | β | β | 0 | HL only | NEW HL β CERTAIN |
| HL.3 | Env. Ethics (HL) | Ecocentrism, deep ecology, rights of nature, intrinsic value, duties to future generations HL only | β | β | β | β | β | β | 0 | HL only | NEW HL β CERTAIN |