IB DP Environmental Systems and Societies – Perspectives, systems and sustainability 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 practice set covers the foundation unit of IB Diploma Programme Environmental Systems and Societies, aligned to the International Baccalaureate Organization Diploma Programme Subject Brief, Environmental systems and societies, first assessment 2026. It tests syllabus sections 1.1 Perspectives, 1.2 Systems and 1.3 Sustainability, which are common to SL and HL. It follows the IB ESS subject brief for first assessment 2026 — the course examined in the May and November 2026, 2027 and 2028 sessions.

The brief names Topic 1’s three subtopics (1.1 Perspectives, 1.2 Systems, 1.3 Sustainability) and gives Topic 1 16 teaching hours at SL and HL, but it sets out no learning outcomes, so the outcomes on this page, and any numbering below Topic 1’s three subtopics, follow the printable ESS checklist, not the brief itself.

Learn the content first in the study guide and the revision notes. The questions here use different scenarios from the Topic 1 Foundations practice set, so you can do both. All data are fictional. Mark allocations are for practice only; the real exam is marked by trained examiners using the IB’s own markschemes.

Questions

1. Outline two inputs to a person’s environmental value system (EVS) and one output from it. [3]

2. Distinguish between a transfer and a transformation, giving one example of each from a water system. [4]

3. Classify each of the following as a provisioning, regulating, cultural or supporting ecosystem service: (i) timber from a forest; (ii) a mangrove reducing storm-surge damage; (iii) soil formation; (iv) a mountain used for hiking. [4]

4. A shallow lake receives phosphorus from farmland. The table shows monitoring data.

Year	Phosphorus (µg/L)	Submerged plant cover (%)
2010	18	62
2011	20	61
2012	22	59
2013	24	58
2014	26	56
2015	28	55
2016	30	20
2017	32	9
2018	34	6
2019	36	5
2020	38	5

(a) Calculate the percentage decrease in plant cover from 2010 to 2015 and from 2015 to 2017. [2] (b) Identify when the lake crossed a tipping point, using evidence from the table. [2] (c) Explain how positive feedback could have driven the change after the tipping point. [3] (d) Suggest why cutting phosphorus back to 26 µg/L may not restore plant cover. [2]

5. A forest plot stores 240 t of carbon. Each year it takes in 18 t C by photosynthesis and loses 8 t C by plant respiration, 7 t C by soil respiration and 1 t C in harvested wood.

(a) Calculate the net annual change in the carbon storage. [2] (b) State whether the plot is acting as a carbon sink or a carbon source. [1] (c) Identify one transfer and one transformation in this system. [2]

6. A savanna grazing area holds 900 t of grass. Grass regrows by 360 t a year. A herd of 300 animals grazes there; each animal eats 1.5 t a year.

(a) Calculate the herd’s annual grass consumption. [1] (b) Calculate the grass stock after one year. [2] (c) Calculate the largest herd the area can support sustainably. [2] (d) Explain how continued overgrazing could create a positive feedback loop. [2]

7. The table shows fictional data for three countries.

Country	EF (gha per person)	Biocapacity (gha per person)	Population (millions)
A	6.2	3.1	30
B	1.4	0.9	80
C	3.3	9.0	5

(a) Calculate the total ecological deficit of Country A. [2] (b) Calculate the ratio of EF to biocapacity for Country B, to 3 significant figures. [1] (c) Identify which country has an ecological reserve and calculate its size per person. [2] (d) Explain one limitation of using ecological footprint alone to compare these countries. [2]

8. A company proposes a tidal barrage across an estuary. Three stakeholders comment.

• Fishers’ co-operative: “We will support it if the company pays for the catch we lose.”
• Company engineer: “Fish-friendly turbines and lock gates will solve any ecological problem.”
• Birdwatching trust: “The mudflats feed thousands of wading birds. They must not be flooded, whatever the power output.”

Identify the EVS of each stakeholder and justify each with evidence from their words. [6]

9. Evaluate the planetary boundaries model as a tool for managing global sustainability. [6]

10. Outline three stages of an environmental impact assessment (EIA) and state one limitation of EIAs. [4]

11. To what extent can the doughnut economics model and the circular economy help a city move towards sustainability? [9]

Answers

1. Input: education or schooling shapes what the person knows about the environment. [1] Input: culture, religion or media sets which values seem normal. [1] Output: a decision or action, such as how they vote or what they buy. [1] [3] Examiner insight: “Outline” needs a brief account of each point, so a bare list of three words may not earn full credit.

2. A transfer moves matter or energy without changing its form or state. [1] Example: river water flowing downstream into a lake. [1] A transformation changes the form or state. [1] Example: evaporation of lake water to water vapour. [1] [4] Examiner insight: An example only scores if it matches the definition — infiltration is a transfer, not a transformation.

3. (i) provisioning [1] (ii) regulating [1] (iii) supporting [1] (iv) cultural [1] [4] Examiner insight: Each classification is marked on its own, so answer every item even if you are unsure of one.

4. (a) 2010–2015: (62 − 55) ÷ 62 × 100 = 11.3% [1]; 2015–2017: (55 − 9) ÷ 55 × 100 = 83.6% [1] (b) Between 2015 and 2016. [1] Cover fell by 35 percentage points in one year (55% to 20%), while phosphorus rose by the same 2 µg/L as every other year. [1] (c) Fewer plants means less rooting to hold sediment, so the water becomes cloudier. [1] Cloudy water lets less light reach the bottom. [1] So more plants die, and the loop continues, amplifying the decline. [1] (d) The lake is now in a new, stable turbid state held in place by its own feedback. [1] Phosphorus stored in sediments can keep being released, so conditions do not return to those of 2014. [1] Examiner insight: Percentages need the correct base (the earlier value); dividing by the later value is a method error and loses the mark.

5. (a) Outputs = 8 + 7 + 1 = 16 t C [1]; net change = 18 − 16 = +2 t C per year [1] (b) Carbon sink — the storage is increasing. [1] (c) Transfer: carbon removed in harvested wood (no change of form). [1] Transformation: photosynthesis, CO₂ turned into organic carbon (or respiration). [1] Examiner insight: Give the sign and the unit (t C per year); “2” alone is incomplete.

6. (a) 300 × 1.5 = 450 t per year [1] (b) 900 + 360 − 450 [1] = 810 t [1] (c) 360 ÷ 1.5 [1] = 240 animals (the herd must fall by 60) [1] (d) Less grass cover exposes soil, which erodes and loses nutrients. [1] Less grass then regrows, so natural income falls further and the same herd overgrazes even more. [1] Examiner insight: In (c), the sustainable herd is based on natural income (360 t), not on the whole stock (900 t) — using the stock is a common method error.

7. (a) Deficit per person = 6.2 − 3.1 = 3.1 gha [1]; total = 3.1 × 30 million = 93 million gha [1] (b) 1.4 ÷ 0.9 = 1.56 [1] (c) Country C [1]; reserve = 9.0 − 3.3 = 5.7 gha per person [1] (d) EF combines all resource use into one area figure [1], so it does not show which resource is under most pressure (water, fish, soil) or where a limit will be reached first. [1] Accept other limitations explained in the same way, such as a per-person average hiding unequal consumption. Examiner insight: Keep “per person” and “total” apart — 3.1 gha is not the answer to (a).

8. Fishers: anthropocentric [1] — they value the estuary for the income it gives people, and accept the project if the loss is paid for. [1] Engineer: technocentric [1] — trusts “fish-friendly turbines” to “solve any ecological problem”. [1] Birdwatching trust: ecocentric [1] — puts the birds’ habitat first “whatever the power output”. [1] [6] Examiner insight: Each label and each justification are credited separately; a justification that does not use the stakeholder’s own words earns less.

9. Indicative points, one mark each (in the real exam, extended answers are judged as a whole against the IB’s own markscheme, not by counting points):

• Strength: it sets out nine global limits, so it gives a clear picture of the overall pressure on the Earth system. [1]
• Strength: it links crossing a boundary with the risk of tipping points, which supports precaution. [1]
• Strength: it lets progress be tracked and compared over time. [1]
• Limitation: it is global, so it does not show local problems or which countries cause the pressure. [1]
• Limitation: some boundaries are hard to measure and their positions are uncertain. [1]
• Conclusion: useful for setting global targets, but it must be combined with local data and social measures, such as those in the doughnut model. [1] [6] Examiner insight: “Evaluate” needs strengths and limitations and a judgement; a one-sided answer cannot reach the top of the range.

10. Baseline study of the site before development. [1] Prediction of likely impacts on the environment and people. [1] Mitigation measures to reduce the impacts, followed by monitoring. [1] Limitation: predictions are uncertain, or baseline data may cover too short a period. [1] [4] Examiner insight: Stages should be given in a logical order; a limitation must be about the EIA process, not about the development.

11. Indicative points, one mark each (an indicative list; other valid, well-supported points can also earn credit, and the real exam judges the answer as a whole, not point by point):

• The doughnut sets a social foundation (housing, water, health) and an ecological ceiling, so a city can check both people’s needs and environmental limits. [1]
• This matches the three pillars of sustainability better than an economic target alone. [1]
• Example: a city could measure how many residents lack clean water alongside its carbon footprint. [1]
• The circular economy keeps materials in use through repair, reuse and recycling, cutting waste and raw-material demand. [1]
• This reduces the city’s ecological footprint by lowering the land needed to absorb waste. [1]
• Limitation: a city imports most of its food and goods, so much of its footprint lies outside its control. [1]
• Limitation: both need data, money and political support; residents with different EVSs may resist changes. [1]
• Limitation: recycling still uses energy, and not all materials can be kept in use. [1]
• Judgement: together they help to a large extent in setting direction, but only with national policy and changes in consumption. [1] [9] Examiner insight: “To what extent” needs a clear judgement supported by the arguments above; balanced points with no conclusion lose the evaluation credit.

Where marks are usually lost

• Dividing by the new value instead of the original when calculating a percentage change.
• Using the whole stock instead of natural income to judge a sustainable harvest.
• Mixing “per person” and “total” footprint values, or dropping gha.
• Calling a change “positive feedback” just because the outcome is bad.
• Naming a tipping point without quoting data that shows the sudden shift.
• Labelling an EVS without quoting the stakeholder.
• Giving only strengths when the command term is “evaluate” or “to what extent”.
• Classifying a process as a transfer when it involves a change of state.

Next steps

• Revise with the revision notes.
• Re-read the study guide.
• Visit the ESS course hub.
• Tick off topics on the printable checklist.
• Try all free 10-minute diagnostics.
• Book a free trial class.

Official syllabus

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