Baccalauréat international · IB Diploma
Environmental Systems and Societies · SL
Papers, samples and curriculum documents for this course. · Dossiers, échantillons et documents de programme pour ce cours.
Course units and learning goals · Unités de cours et objectifs d'apprentissage
These lessons teach selected course objectives. Check the remaining coverage gaps; the material is not a complete preparation programme. · Ces leçons abordent des objectifs de cours sélectionnés. Vérifiez les lacunes restantes en couverture ; ce matériel ne constitue pas un programme d'entraînement complet.
1 · Foundation
- An amount held within a system.
- Separate physical evidence from value judgements. A stock is an amount at a time; a flow is an amount per time. Sustainability decisions require ecological, social and economic evidence and a stated scale.
- Draw the system boundary before calculating a budget. Identify inflows, outflows and possible unmeasured terms. Compare stakeholder claims using the same evidence, then explain where values lead to different choices.
- stock
- An amount held within a system
- flow · flux
- Transfer of an amount per unit time
2 · Ecology
- A defined area used for sampling.
- Estimate total abundance by multiplying mean density by area, with consistent units. This assumes sampled areas represent the habitat. Patchiness and too few samples widen uncertainty.
- Choose coordinates with random numbers before visiting the patches. Record quadrat area and counting rules. For a transect, use fixed distances and measure a relevant abiotic variable. Do not damage habitats or sample unsafe locations.
- An amount held within a system.
- Separate physical evidence from value judgements. A stock is an amount at a time; a flow is an amount per time. Sustainability decisions require ecological, social and economic evidence and a stated scale.
- Draw the system boundary before calculating a budget. Identify inflows, outflows and possible unmeasured terms. Compare stakeholder claims using the same evidence, then explain where values lead to different choices.
- quadrat
- A defined area used for sampling
- population
- Organisms of one species in a defined area
- stock
- An amount held within a system
- flow · flux
- Transfer of an amount per unit time
3 · Biodiversity and conservation
- The number of species recorded.
- Compare surveys with similar area, effort, season and identification rules. A diversity index is meaningful only with its formula and conventions specified. Habitat fragmentation can affect movement and gene flow even when total area changes little.
- Use non-destructive field sampling approved by the school. Identify organisms with a suitable key and record uncertain identifications rather than inventing species. Combine ecological evidence with stakeholder perspectives on land use.
- species richness
- The number of species recorded
- evenness
- How evenly individuals are distributed among species
4 · Water
- Nutrient enrichment with ecological consequences.
- Distinguish concentration from total pollutant load. Dilution can reduce concentration without removing the pollutant mass. A management plan should consider upstream causes, users and effects on other parts of the catchment.
- Collect approved water-quality observations at matched sites and times. Use calibrated instruments and consistent sampling depth. Avoid contact with contaminated water and do not infer potability from clarity.
- eutrophication
- Nutrient enrichment with ecological consequences
- pollutant load
- Mass of pollutant transferred per time
5 · Land
- Removal and transport of soil or rock.
- Distinguish total yield from yield per area and energy input. Sustainable management must consider regeneration rates and impacts beyond the farm boundary. Different stakeholders may rank food security, biodiversity and income differently.
- Compare management options using a stated functional unit and the same timescale. Use approved secondary datasets or non-destructive soil observations. Explain trade-offs instead of claiming a method has no disadvantages.
- erosion
- Removal and transport of soil or rock
- resource
- A material or service used to meet needs
6 · Atmosphere and climate change
- Actions addressing causes of environmental change.
- Distinguish mitigation, which addresses drivers, from adaptation, which reduces harm from impacts. A policy assessment needs evidence about effectiveness, cost, equity and uncertainty; one criterion is not the entire decision.
- Compare multi-year data using consistent baselines. State the region, timescale and uncertainty. At HL, connect a management decision to law, economics and ethics rather than treating these lenses as extra definitions only.
- mitigation
- Actions addressing causes of environmental change
- adaptation
- Actions reducing harm from environmental impacts
7 · Natural resources
- Removal and transport of soil or rock.
- Distinguish total yield from yield per area and energy input. Sustainable management must consider regeneration rates and impacts beyond the farm boundary. Different stakeholders may rank food security, biodiversity and income differently.
- Compare management options using a stated functional unit and the same timescale. Use approved secondary datasets or non-destructive soil observations. Explain trade-offs instead of claiming a method has no disadvantages.
- erosion
- Removal and transport of soil or rock
- resource
- A material or service used to meet needs
8 · Human populations and urban systems
- Movement into a population.
- Compare rates with a common denominator and interval. An average can hide unequal access to services. At HL, evaluate how economic incentives, legal responsibilities and ethical priorities change an urban management proposal.
- Use published demographic and city-service data with dates and definitions. Protect privacy when collecting local opinions. Compare the same geographical boundary rather than mixing an urban core with a whole metropolitan region.
- immigration
- Movement into a population
- indicator
- A measure of a specified condition
Practical · Experimental programme
- A quantified limitation on a measured result.
- For a product or quotient, adding fractional uncertainties is a common maximum-uncertainty approximation. For a difference, add absolute uncertainties. A nonzero intercept can reveal an offset or an incomplete model.
- Show units on axes and choose a sensible scale. Plot uncertainty bars where justified, draw a best-fit line rather than joining every point, and estimate steepest and shallowest plausible gradients when the course method calls for them.
- uncertainty
- A quantified limitation on a measured result
- systematic error
- A consistent measurement bias
Preparing for this qualification · Préparation à cette qualification
- ESS integrates ecological evidence with human values, systems and sustainability; it is not a generic Biology course.
- HL adds environmental law, environmental/ecological economics and ethics as lenses integrated with topic evidence, alongside deeper topic coverage.
- Both levels have practical work 30 h, collaborative sciences project 10 h and individual investigation 10 h. Use school-approved fieldwork and ethical social-data collection.
- Written assessment and investigation details are recorded from the 2026 brief; the old SL-only 2017 brief is not the current course.
- 2026 assessment: SL Paper 1 is 1 h/25%, Paper 2 is 2 h/50%, investigation 25%; HL Paper 1 is 2 h/30%, Paper 2 is 2.5 h/50%, investigation 20%. Paper 1 uses an unseen case study; Paper 2 has short/data questions and structured essays. The individual investigation is a real student-formulated inquiry, 10 h and a maximum 3,000-word report.
Teaching coverage still needed · Couverture pédagogique encore nécessaire
- Exact topic statements require the current full ESS guide; focus cases are partial.
Specifications and sample documents · Spécifications et documents d'échantillon
- Environmental Systems and Societies — Subject brief · 2026 ↗
First assessment: 2026
- Environmental Systems and Societies — Subject brief · 2017 ↗
First assessment: 2017
Course materials · Matériel pédagogique
- Study notes · Notes de cours →
- Revision questions · Questions de révision →
- Teaching guidance · Guide pédagogique · Teacher access · Accès enseignant →
- Teacher diagnostics · Diagnostique enseignant · Teacher access · Accès enseignant →
- Supervised task guidance · Guide pour la tâche supervisée · Teacher access · Accès enseignant →
Course preparation · Préparation du cours
Documents are available. Board-specific notes, assessments and interactive past-paper practice are not yet available for every course. · Les documents sont disponibles. Les notes spécifiques au conseil, les évaluations et la pratique interactive des anciens sujets ne sont pas encore disponibles pour tous les cours.
Lessons · Leçons →