IB DP Environmental Systems and Societies – Natural resources, energy and solid waste Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – the IB holds copyright in its own papers. Use these alongside the official past papers available through your school or the IB store.

This set covers Topic 7 of IB Diploma Programme Environmental Systems and Societies, aligned to the IB Environmental systems and societies subject brief, first assessment 2026: syllabus sections 7.1–7.3, SL and HL. Question 12 uses the HL-only economics lens. It follows the IB ESS subject brief for first assessment 2026 — the course examined in the May and November 2026, 2027 and 2028 sessions.

Links: study guide · revision notes · ESS exam preparation

All data is fictional.

Questions

1. Distinguish between renewable and non-renewable natural capital, giving one example of each. [3]

2. A mangrove forest grows along a tropical coast. Outline one provisioning service and one regulating service it provides to the local community. [2]

3. A community woodland held 5,600 t of wood biomass on 1 January 2024 and 5,880 t on 1 January 2025. No trees were felled during 2024.

(a) Calculate the sustainable yield of the woodland. [2] (b) Express the sustainable yield as a percentage of the 2024 stock. [1] (c) The council proposes to fell 350 t each year. Using a calculation, explain the effect on the woodland’s natural capital over five years. [2] (d) Suggest why the real change in stock could differ from your answer to (c). [1]

4. Electricity generated in a fictional country in 2025 (TWh): coal 48, natural gas 36, oil 6, hydro 54, wind 18, solar 12, geothermal 6.

(a) Calculate the percentage of electricity generated from renewable sources. [2] (b) All of the gas and oil and half of the coal are imported. Calculate the percentage of electricity generated from imported fuels. [2] (c) Explain two ways in which the country’s reliance on hydro could threaten its energy security. [2] (d) Suggest two strategies the country could use to improve its energy security. [2]

5. Explain two factors, other than cost, that influence a society’s choice of energy sources. [4]

6. Waste data for two fictional towns in one year:

	Town A	Town B
Population	50,000	120,000
Total SDW (t)	22,500	42,000
Recycled (t)	4,500	12,600
Composted (t)	2,250	6,300
Incinerated with energy recovery (t)	0	14,700
Landfilled (t)	15,750	8,400

(a) Calculate the SDW produced per person per year in each town. [2] (b) Calculate the percentage of SDW diverted from landfill in each town. [2] (c) Suggest two reasons why waste per person differs between the towns. [2] (d) Evaluate Town B’s use of incineration. [3]

7. Using the pollution management model, outline one strategy at each of its three levels for reducing the impact of single-use plastic packaging. [3]

8. Explain how the tragedy of the commons could lead to the depletion of an aquifer shared by many farmers, and outline one way to prevent it. [4]

9. Explain, with examples, why the value of a natural resource can change over time. [3]

10. To what extent could a country improve its energy security and cut its carbon emissions by replacing coal with a mix of nuclear and wind power? [9]

11. Discuss how a circular economy approach could reduce both the depletion of natural resources and the amount of solid domestic waste. [9]

12. (HL) With reference to environmental and ecological economics, evaluate a landfill tax as a strategy for managing solid domestic waste. [6]

Answers

For questions 10–12 the points are indicative. In the exam, extended answers are judged as a whole against the IB’s criteria, which your teacher will share.

1. Renewable natural capital regenerates within a human timescale if used at or below its rate of growth [1]; non-renewable natural capital forms far more slowly than it is used, so any extraction reduces the stock [1]; one correct example of each, e.g. a forest (renewable) and coal (non-renewable) [1]. Examiner insight: “Distinguish” needs the difference stated for both types; two correct examples with no definitions earn only the example mark.

2. Provisioning: e.g. fuelwood, timber or fish caught from its nursery waters [1]. Regulating: e.g. protecting the coast from storm surges and erosion, or storing carbon [1]. Examiner insight: Two examples of the same service type earn one mark only, so check each example’s category.

3. (a) SY = 5,880 − 5,600 [1] = 280 t per year [1]. (b) 280 ÷ 5,600 × 100 = 5.0% per year [1]. (c) Felling exceeds SY, so the stock falls by 350 − 280 = 70 t per year [1]; after five years it is about 5,600 − 5 × 70 = 5,250 t, so natural capital is being depleted and the plan is unsustainable [1]. (d) Growth would probably not stay at 280 t per year: a smaller stock usually grows more slowly, and weather, pests or fire change growth from year to year [1]. Examiner insight: The accuracy mark in (a) needs the unit and the time period; “280” alone shows the method but not a complete yield.

4. (a) Renewable = 54 + 18 + 12 + 6 = 90 TWh out of 180 TWh [1]; 90 ÷ 180 × 100 = 50.0% [1]. (b) Imported = 36 + 6 + 0.5 × 48 = 66 TWh [1]; 66 ÷ 180 × 100 = 36.7% [1]. (c) Hydro supplies 30% of generation, so drought or reduced river flow (e.g. from climate change) would cut a large share of supply [1]; if the river is shared with another country, upstream dams or disputes could reduce flow [1]. (d) Any two: diversify with more domestic renewables such as wind, solar or geothermal [1]; add storage or interconnectors with neighbours, or cut demand through energy efficiency [1]. Examiner insight: An error in (a) can still earn method marks later if your working is shown, so write each sum out.

5. Factor 1, e.g. availability of local resources [1]: a country with fast rivers and high relief can develop hydro; one without cannot [1]. Factor 2, e.g. political or cultural attitudes [1]: public opposition after a nuclear accident, or a pledge to cut emissions, can rule sources in or out regardless of cost [1]. Examiner insight: Naming a factor earns one mark; the second needs an explanation of how it changes the choice, ideally with an example.

6. (a) Town A: 22,500,000 kg ÷ 50,000 = 450 kg per person per year [1]; Town B: 42,000,000 kg ÷ 120,000 = 350 kg per person per year [1]. (b) Town A: (22,500 − 15,750) ÷ 22,500 × 100 = 30% [1]; Town B: (42,000 − 8,400) ÷ 42,000 × 100 = 80% [1]. (c) Any two: different income or consumption patterns [1]; different packaging rules, collection charges or awareness campaigns [1]. (d) Strength: it keeps 14,700 t out of landfill and recovers energy [1]. Limitation: it releases CO₂, air pollutants and toxic ash, and a plant needing steady waste supply can discourage recycling [1]. Judgement: better than landfill but below reduction, reuse and recycling on the waste hierarchy, so acceptable alongside strong recycling (Town B recycles or composts 45%) [1]. Examiner insight: “Evaluate” needs a strength, a limitation and a judgement; a list of advantages alone cannot earn the full three marks.

7. Altering human activity: e.g. refillable containers or a ban on some single-use items [1]. Controlling release: e.g. a deposit-return scheme or separate plastics collection for recycling [1]. Clean-up and restoration: e.g. beach and river litter clean-ups [1]. Examiner insight: Each strategy only scores if it sits at the correct level; recycling handles waste already made, so it fits controlling release.

8. The aquifer is a common-pool resource no single farmer owns [1]. Each farmer gains the full benefit of pumping more, while the cost of the falling water table is shared by all [1], so abstraction exceeds recharge and the aquifer is depleted [1]. Prevention: e.g. metered quotas keeping total abstraction below recharge, enforced by a farmers’ association or the state [1]. Examiner insight: The key mark needs individual gain contrasted with shared cost; “farmers use too much water” is the outcome, not the mechanism.

9. Technology: e.g. lithium became far more valuable with rechargeable batteries [1]. Culture: e.g. a forest once valued for timber may be protected for recreation or spiritual value [1]. Price or substitution: e.g. a higher price makes low-grade ore worth mining; kerosene cut the value of whale oil [1]. Examiner insight: Each mark needs a reason linked to an example; a list of resources whose value changed, with no reason, earns nothing.

10. Indicative points:

• Coal is high-carbon, so replacing it cuts CO₂ emissions per unit of electricity [1].
• Nuclear gives steady output and very low operational CO₂, which balances the variability of wind [1].
• Wind is domestic and needs no fuel, so imports and price shocks fall [1].
• Uranium may be imported, though it is compact and easy to stockpile [1].
• Wind is intermittent, so storage, a flexible grid or backup capacity is needed [1].
• Nuclear plants are costly and slow to build, so emissions continue meanwhile [1].
• Radioactive waste and accident risk reduce public acceptance [1].
• Efficiency and conservation reduce the capacity needed [1].
• Conclusion: the mix improves both goals to a large extent, but only if storage, fuel supply and build times are managed [1]. Examiner insight: “To what extent” needs a conclusion that weighs both goals; listing advantages only cannot earn the judgement point.

11. Indicative points:

• A circular economy keeps materials in use for as long as possible and designs out waste [1].
• Designing durable, repairable products reduces demand for new raw materials [1].
• Reuse and remanufacturing keep products in use with little extra energy [1].
• Recycling returns metals and plastics to production, reducing mining and extraction [1].
• Composting returns nutrients to soil, closing the loop for organic waste [1].
• Less material reaches landfill, cutting methane and leachate [1].
• Limitation: some materials degrade on recycling, and recycling itself uses energy [1].
• Limitation: it needs slow changes in business models, habits and policy [1].
• Conclusion: it reduces both depletion and waste, but works best with reduction at source [1]. Examiner insight: “Discuss” needs limitations as well as benefits, each linked to depletion or to waste.

12. (HL) Indicative points:

• Landfill has an external cost (methane, leachate, land use) not paid by the waste producer [1].
• A tax per tonne makes landfill dearer, so the price reflects more of its true cost [1].
• This gives councils and businesses a reason to reduce, recycle and compost [1].
• Revenue can fund recycling facilities or clean-up [1].
• Limitation: it may increase illegal dumping or shift waste to incineration or export [1].
• Judgement: effective if the rate is high enough and alternatives exist, so it works best alongside recycling investment and enforcement [1]. Examiner insight: Credit depends on economic reasoning — external costs and price signals — not just describing the tax.

Where marks are usually lost

• Giving sustainable yield without “per year”, or confusing it with the planned harvest.
• Placing nuclear power in the renewable total when calculating an energy-mix percentage.
• Naming a factor or strategy without explaining how it works, on a question that says “explain”.
• Putting a strategy at the wrong level of the pollution management model.
• One-sided answers to “evaluate”, “discuss” and “to what extent” questions, with no judgement.
• Dropping units (t, TWh, kg per person per year) from calculated answers.
• In HL lens questions, giving general environmental points without economic reasoning.

Next steps

• Recap the definitions with the revision notes.
• Re-learn anything you missed from the study guide.
• Browse the ESS course hub.
• Tick off topics on the printable ESS checklist.
• Try all free 10-minute diagnostics.
• Book a free trial class.

Official syllabus

International Baccalaureate Organization, Diploma Programme Subject Brief, Environmental systems The brief lists subtopics for Topic 1 only; the subtopic numbering on this page follows the printable ESS checklist. and societies, first assessment 2026.

The brief gives Topic 7 Natural resources 10 teaching hours at SL and 18 at HL. It does not list the subtopics or learning outcomes for this topic, so the numbered subtopics and outcomes on this page follow the syllabus numbering used in the printable ESS checklist, not the brief itself.