Question 1
Define sustainability.
[2]
Question 2
Figure 1 shows two models of sustainability.
Identify the strong sustainability model.
[1]
Distinguish between the assumptions represented by models A and B.
[2]
Question 3
A catchment authority used mean annual nitrate concentration as an indicator of river sustainability. Figure 2 shows results following the introduction of improved fertilizer management.
Calculate the percentage decrease in mean nitrate concentration between 2019 and 2024.
[2]
State one limitation of using nitrate concentration alone to assess sustainability in this catchment.
[1]
Question 4
Figure 3 compares the ecological footprint and biocapacity of a region in 2025.
Calculate the region's biocapacity deficit per person.
[1]
Explain why the data indicate that the region is environmentally unsustainable.
[2]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 5
Students in several communities use a shared mobile application to upload georeferenced observations of flowering dates for a native tree species.
Outline one way these citizen-science data could contribute to sustainability monitoring.
[1]
Outline two measures that could improve the reliability of the data.
[2]
Question 6
Figure 1 shows the ecological-footprint components and city biocapacity per person for four residents of Lydon City.
Calculate the total ecological footprint of resident R.
[1]
Identify the residents whose ecological footprints represent a biocapacity deficit, and state which resident has the greatest deficit.
[2]
Explain how two changes in resident P's consumption could reduce the biocapacity deficit shown.
[3]
Question 7
Most river water entering Lake Nareen has been diverted for irrigated agriculture. The lake has become smaller and more saline, and populations of native fish have declined rapidly.
Explain how continued water diversion could cause collapse of the lake's socio-ecological system.
[4]
Question 8
A country reports a 3% increase in GDP following extensive timber extraction. Expenditure on cleaning polluted rivers also contributed to GDP growth.
Explain why the increase in GDP does not demonstrate that development was sustainable.
[2]
Outline how green GDP would provide a different assessment.
[2]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 9
A city closes waste-transfer stations in high-income districts and builds a larger facility beside a low-income settlement. The city states that consolidating the facilities will reduce overall waste-system operating costs and the number of vehicle journeys. Residents of the settlement are not consulted and report increased noise, odour and heavy vehicle traffic.
Identify two features of environmental injustice in this example.
[2]
Explain how the decision may improve sustainability at one operating scale while reducing it at another.
[2]
Question 10
Figure 5 represents the doughnut economics model.
Distinguish between social shortfall and ecological overshoot in the model.
[2]
Explain why an economy must be both regenerative and distributive to move into the safe and just space.
[2]
Question 11
The figures show changes in ecological footprint and biocapacity in the island state of Navora. Footprint values include the productive land and water associated with imported goods.
Navora's ecological footprint by component, 2004–2024.
| Year | Food / | Housing / | Transport / | Goods / | Services / | Total / |
|---|---|---|---|---|---|---|
| 2004 | 0.60 | 0.40 | 0.40 | 0.40 | 0.30 | 2.10 |
| 2014 | 0.75 | 0.45 | 0.70 | 0.45 | 0.35 | 2.70 |
| 2024 | 0.90 | 0.50 | 1.00 | 0.50 | 0.40 | 3.30 |
Identify the largest component of Navora's ecological footprint in 2024.
[1]
Calculate Navora's biocapacity deficit in 2024 as a percentage of its biocapacity. Show your working.
[2]
Describe the changes in ecological footprint and biocapacity between 2004 and 2024.
[3]
Explain two ways in which Navora could be maintaining consumption despite its biocapacity deficit.
[3]
Evaluate the use of ecological footprint and biocapacity as indicators of Navora's sustainability.
[4]
Question 12
A citizen-science programme monitors nitrate concentration in the Rema River downstream of an agricultural area. Volunteers use test kits each month, while a professional laboratory analyses a sample from the same site every third month. A water-quality guideline of 10 mg per litre is shown.
Annual mean nitrate concentration, participation and sampling coverage in the Rema River citizen-science programme.
| Year | Annual mean nitrate / mg L | Active volunteers | Monthly observations |
|---|---|---|---|
| 2022 | 14.0 | 84 | 12 |
| 2023 | 12.5 | 71 | 11 |
| 2024 | 10.0 | 49 | 9 |
| 2025 | 8.4 | 31 | 7 |
Identify the first month in 2022 when the volunteer measurements exceeded the water-quality guideline.
[1]
Calculate the percentage decrease in annual mean nitrate concentration from 2022 to 2025. Show your working.
[2]
Describe the relationship between nitrate concentration and participation from 2022 to 2025.
[2]
Explain how nitrate concentration may be used as an indicator of environmental sustainability in the Rema River.
[3]
Evaluate the reliability and usefulness of the citizen-science programme for assessing long-term sustainability.
[5]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 13
Students used the same method to measure nitrate concentration at three sites along the River Dalen once each month. The guideline concentration is shown in Figure 2.
Describe the annual pattern in nitrate concentration at Site B.
[2]
State the number of months in which Site B exceeds the nitrate guideline.
[1]
Suggest three limitations of using these data alone to assess the environmental sustainability of the river system.
[3]
Question 14
Figure 3 shows access to piped water and the average share of household income spent on water in three districts of the city of Harana.
Figure 3. Reliable piped-water access and average household water expenditure by income group and district. Households without reliable piped water commonly purchase water from private vendors.
| District | Household income group | Reliable piped-water access / % | Water expenditure / % of income |
|---|---|---|---|
| Riverside | Lowest-income | 42 | 12 |
| Riverside | Highest-income | 94 | 2 |
| Central | Lowest-income | 68 | 8 |
| Central | Highest-income | 97 | 2 |
| Eastbank | Lowest-income | 31 | 16 |
| Eastbank | Highest-income | 89 | 3 |
Calculate the difference in reliable piped-water access between the lowest-income and highest-income households in Eastbank.
[1]
Describe two relationships between income and access to water shown in Figure 3.
[2]
Explain how the patterns shown represent an issue of environmental justice.
[3]
Question 15
Figure 4 compares GDP and estimated green GDP for three countries. Green GDP is calculated by subtracting estimated environmental costs from GDP.
Calculate the environmental cost as a percentage of GDP for Norvia.
[2]
Compare the ranking of the countries using GDP with their ranking using green GDP.
[2]
Explain why green GDP may provide a more useful indication of sustainable development than GDP for these countries.
[2]
Question 16
Figure 6 shows selected flows in a circular economy.
Explain why maintenance and reuse are generally preferred to recycling in the technical cycle.
[2]
Outline how the biological cycle can contribute to regeneration of natural systems.
[2]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 17
A city programme uses the UN Sustainable Development Goals to support affordable housing and solar-powered public transport. Construction of the housing would remove part of an urban wetland.
Explain one conflict between sustainability goals in this programme.
[2]
Outline one use and one limitation of the SDGs as a framework for this programme.
[2]
Question 18
The city of Luwala has expanded rapidly. District A is an affluent central district, whereas District B is a low-income peripheral district. Water is supplied through household connections in central districts and communal standpipes in outer districts. A privately operated landfill receives waste from the whole city.
Calculate the difference in household access to safely managed water between districts A and B.
[2]
Identify two pieces of evidence that district B experiences greater environmental inequality than district A.
[2]
Explain how unequal access to water could reinforce poverty in district B.
[3]
Explain why the location of the landfill is an issue of environmental justice.
[2]
Evaluate a proposal to increase the city-wide water tariff and use the revenue to extend piped water to district B.
[5]
Question 19
The government of the lower-income country of Belesia is selecting a transport-development plan for its capital. The plans are intended to contribute to the UN Sustainable Development Goals (SDGs).
Sustainability appraisal of three transport-development plans in Belesia.
| Measure | Plan X | Plan Y | Plan Z |
|---|---|---|---|
| Transport option | Urban expressway | Electric bus network | Diesel bus network |
| Construction cost / million units | 620 | 480 | 310 |
| Expected low-income users / day | 18 000 | 126 000 | 94 000 |
| Wetland loss / ha | 42 | 6 | 9 |
| Annual operational emissions / tonnes | 210 000 | 58 000 | 165 000 |
| Construction jobs | 2400 | 1900 | 1500 |
| Permanent jobs | — | 850 | 620 |
Identify the plan with the lowest annual operational emissions and the plan with the lowest construction cost.
[2]
Calculate how many times greater the expected number of low-income users is for Plan Y than for Plan X.
[2]
Explain how Plan Y could contribute to the environmental, social and economic pillars of sustainability.
[3]
Explain two possible conflicts between SDG-related objectives in Plan Y.
[3]
Evaluate whether Plan Y represents sustainable development.
[5]
Question 20
Figure 5 presents control-variable data for three planetary processes. Each value is expressed as a percentage of its proposed planetary boundary; represents the boundary. The proposed boundary has an uncertainty range from to .
Determine the first recorded year in which each process exceeded 100% of its proposed boundary.
[2]
Calculate the percentage increase in the climate-change control variable between 1980 and 2020.
[2]
Analyse what the data suggest about the usefulness and limitations of a planetary boundary as an indicator of sustainability.
[3]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 21
The city of Belora used a doughnut economics framework to assess social shortfalls and ecological overshoot. A value of 100 represents the minimum social foundation or the maximum ecological ceiling.
Belora doughnut-economics assessment (index threshold: 100) and policy proposals.
| Component | Indicator or proposal | Index | Details |
|---|---|---|---|
| Social foundation | Nutritious food | 82 | |
| Social foundation | Safe water | 96 | |
| Social foundation | Secondary education | 74 | |
| Social foundation | Adequate housing | 88 | |
| Social foundation | Political voice | 67 | |
| Social foundation | Health care | 103 | |
| Ecological ceiling | Carbon emissions | 146 | |
| Ecological ceiling | Freshwater use | 91 | |
| Ecological ceiling | Nitrogen release | 132 | |
| Ecological ceiling | Land conversion | 118 | |
| Ecological ceiling | Material consumption | 154 | |
| Ecological ceiling | Air pollution | 97 | |
| Policy proposal | Proposal X | Retrofit low-income housing; install community solar; fund training for local workers. | |
| Policy proposal | Proposal Y | Expand an automated recycling plant; reduce grants for affordable housing. |
Identify the greatest social shortfall and the greatest ecological overshoot.
[2]
State the number of social indicators below the foundation and the number of ecological indicators beyond the ceiling.
[2]
Analyse which proposal better supports a regenerative and distributive economy in Belora.
[3]
Question 22
Figure 7 shows annual material flows through a company that manufactures modular office furniture. All values are in tonnes per year.
Annual material flows for a modular office-furniture manufacturer.
| Stage | Material flow | Flow class | Mass / tonnes per year |
|---|---|---|---|
| Inputs | Virgin material production | Input | 600 |
| Inputs | Recovered material production | Input | 400 |
| Production | Production sold products | Product output | 850 |
| Production | Production offcuts | Production residue | 150 |
| Production offcuts | Offcuts recycled into company inputs | Recycling loop | 120 |
| Production offcuts | Offcuts landfill | Final leakage | 30 |
| End of use | Sold products maintenance for continued use | Tight technical loop | 200 |
| End of use | Sold products reuse or redistribution | Tight technical loop | 180 |
| End of use | Sold products refurbishment | Tight technical loop | 120 |
| End of use | Sold products remanufacture | Technical loop | 100 |
| End of use | Sold products recycled into company inputs | Recycling loop | 80 |
| End of use | Sold products recycled by other industries | Recycling loop | 90 |
| End of use | Sold products incineration | Final leakage | 50 |
| End of use | Sold products landfill | Final leakage | 30 |
Calculate the percentage of total production input supplied by recovered material.
[2]
Identify the largest end-of-use technical loop and the total mass of material lost through incineration and landfill.
[2]
Suggest two changes that would move the company further towards a circular economy.
[2]
Question 23
A regional council is comparing two development projects. Figure 8(a) shows their environmental, social and economic sustainability scores. Figure 8(b) shows two sustainability models used by council advisers.
Calculate the mean sustainability score for each project.
[2]
Identify which project would be selected if the council used the mean score alone, and which project meets the ecological minimum.
[2]
Explain why the weak and strong sustainability models could lead advisers to recommend different projects.
[3]
Question 24
Figure 4 shows a simplified control variable used to assess one planetary boundary. The proposed boundary for phosphorus flow to the oceans is 11 teragrams per year.
Determine the first year shown in which the proposed boundary had been crossed.
[1]
Calculate the percentage by which phosphorus flow exceeded the proposed boundary in 2020.
[2]
State one reason why crossing the boundary should not be interpreted as proof that immediate ecosystem collapse will occur.
[1]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 25
The economy of Terranova depends on timber, mineral extraction and tourism. The government publishes both GDP and estimated environmental costs. Green GDP is calculated by subtracting environmental costs from GDP.
Terranova environmental costs and selected development indicators, 2020–2025.
| Year | Forest depletion / billion currency units | Mineral depletion / billion currency units | Air and water pollution / billion currency units | Ecosystem restoration / billion currency units | Total environmental costs / billion currency units | Forest cover / % of national land area | Tourism employment / people |
|---|---|---|---|---|---|---|---|
| 2020 | 2 | 1 | 1 | 1 | 5 | 62 | 220 000 |
| 2025 | 7 | 4 | 5 | 2 | 18 | 51 | 250 000 |
Calculate Terranova's green GDP in 2025.
[2]
Calculate the percentage increase in GDP between 2020 and 2025.
[2]
Analyse what the differences between GDP and green GDP indicate about Terranova's development.
[3]
Explain how the data support a strong sustainability model rather than a weak sustainability model.
[3]
Evaluate the use of green GDP for guiding Terranova's development policy.
[5]
Question 26
Orbis Devices manufactures laptop computers. In 2024 it introduced product leasing, modular design, repair services and a supplier take-back scheme as part of a circular-economy strategy.
Orbis Devices indicators before and after its circular-economy strategy.
| Indicator | 2024 | 2027 |
|---|---|---|
| Virgin material input / tonnes | 10 000 | 5 800 |
| Waste leakage / tonnes | 5 200 | 2 500 |
| Life-cycle emissions / tonnes | 24 000 | 15 000 |
| Total employment / jobs | 120 | 190 |
| Annual operating cost / million currency units | 8.0 | 8.6 |
Calculate the percentage of end-of-use material directed to reuse or repair, refurbishment, or recycling in 2027.
[2]
Calculate the percentage decrease in virgin material input between 2024 and 2027.
[2]
Analyse the evidence that Orbis Devices has decoupled economic activity from environmental pressure.
[3]
Explain why reuse or repair and refurbishment are generally preferable to material recycling in a circular economy.
[3]
Evaluate the sustainability of Orbis Devices' circular-economy strategy.
[5]
Question 27
Outline the environmental, social and economic pillars of sustainability.
[4]
Explain why development that increases short-term economic production may not be sustainable.
[7]
Using named examples, to what extent are challenges of sustainable development also challenges of environmental justice?
[9]
Question 28
Distinguish between an ecological footprint, a carbon footprint and a water footprint.
[4]
Explain how a community could use citizen science and a range of sustainability indicators to assess the long-term viability of its socio-ecological system.
[7]
Evaluate the use of quantitative indicators for determining whether a named community, city or country is becoming more sustainable.
[9]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 29
Explain how unsustainable use of a natural resource can lead to ecosystem collapse.
[4]
Explain how actions at different operating scales could improve the sustainability of a fishery that is experiencing declining catches.
[7]
Using real-world examples, discuss the effectiveness of the UN Sustainable Development Goals as a framework for preventing resource overuse and supporting human well-being.
[9]
Question 30
Researchers have reconstructed global human fixation of reactive nitrogen. The central proposed planetary boundary is 60 teragrams of nitrogen per year, with an uncertainty range from 50 to 70 teragrams per year.
Determine the year in which human fixation of reactive nitrogen first reached the central proposed boundary and the year in which it reached the upper uncertainty limit.
[2]
Calculate the percentage by which the 2025 value exceeds the central proposed boundary.
[2]
Analyse the change in human fixation of reactive nitrogen between 1950 and 2025.
[3]
Explain how excessive reactive nitrogen may interact with two other planetary boundaries.
[3]
Evaluate the planetary boundaries model as a framework for sustainability decision-making.
[5]
Question 31
The city of Meridia has adapted the doughnut economics model to compare social conditions with ecological pressures. The inner social foundation represents minimum standards. The outer ecological ceiling represents maximum environmental pressures.
Figure 7(b): Social and ecological indicators for districts C and D in Meridia.
| Indicator | District C | District D | Unit |
|---|---|---|---|
| Households below affordable-housing standard | Percent of households | ||
| Households without reliable clean energy | Percent of households | ||
| Residents reporting meaningful influence over city decisions | Percent of residents | ||
| Consumption-based carbon footprint | 14.0 | 3.8 | |
| Material footprint | 26 | 9 | |
| Mean nitrogen pollution exposure | 18 | 46 |
Identify one city-wide social shortfall and one city-wide ecological overshoot.
[2]
Compare the sustainability conditions of districts C and D.
[3]
Explain how the data demonstrate environmental injustice.
[3]
Explain how two elements of the proposed policy package reflect regenerative or distributive design.
[3]
Evaluate the usefulness of the doughnut economics model for guiding Meridia's policy package.
[5]
Question 32
Outline the meaning of a planetary boundary and the significance of crossing one.
[3]
Explain how human activities can cause interactions among planetary boundaries.
[8]
Using real-world examples, evaluate the planetary boundaries model as a framework for sustainability decision-making at global and national scales.
[9]
Build a Practice Exam — ESS HL
Test your knowledge with a custom paper containing questions from selected topics.
Question 33
Explain the social foundation, ecological ceiling and safe and just space represented by the doughnut economics model.
[4]
Explain how regenerative and distributive design could move an urban economy towards the safe and just space.
[7]
Using named examples, to what extent is the doughnut economics model more useful than models based only on the three pillars of sustainability for guiding urban development?
[9]
Question 34
Distinguish between a linear economy and a circular economy.
[3]
Explain how biological and technical cycles can conserve resource value and support sustainability in a circular economy.
[8]
Using named examples, evaluate the claim that a circular economy can achieve economic development without increasing environmental pressure.
[9]
The Ultimate All-in-One
IB Platform
All content on this website has been developed independently from and is not endorsed by the International Baccalaureate Organization. International Baccalaureate and IB are registered trademarks owned by the International Baccalaureate Organization.