Photo: via Wikimedia Commons.
Bhutan, a small Himalayan kingdom of about 800,000 people, is the world's only verified carbon-negative country: it absorbs more carbon dioxide than its entire economy emits.
How does a country actually pull that off?
It built forest protection and a wellbeing measure into national policy. Bhutan's constitution requires at least 60% forest cover be maintained for future generations; actual coverage runs even higher, around 72%. Those forests sequester roughly nine million tonnes of carbon dioxide a year, against roughly two million tonnes the country's whole economy emits (2020 figures). Bhutan also exports hydroelectric power, offsetting emissions elsewhere.
Just as tellingly, Bhutan does not track success primarily through GDP. It uses a Gross National Happiness (GNH) index instead, an explicit alternative to the growth-only economic measures most countries default to. Both choices, protecting a storage (forest) and rejecting a narrow economic indicator, run through everything else in this tab.
- Constitutional minimum: at least 60% forest cover maintained permanently; actual coverage: around 72.3% of national land area.
- Forests sequester an estimated 9 million tonnes of CO2 per year, against roughly 2 million tonnes emitted by the whole economy (2020 figures): a carbon-negative balance.
- Hydroelectric power exports, mainly to India, offset additional emissions beyond the country's own borders.
- Gross National Happiness (GNH), not GDP, is the country's headline development measure, explicitly weighing wellbeing, culture and environmental conservation alongside economic activity.
Sources: World Bank Blogs, 2025; Climate Council; National Geographic; Harvard International Review, "Carbon Negativity in Bhutan."
Forest cover as a percentage of land area. The world average sits at 31%, against a global footprint that has exceeded biocapacity every year since the early 1970s. Bhutan's actual coverage clears its own constitutional floor by more than 12 percentage points; Suriname, one of only three carbon-negative countries alongside Bhutan and Panama, is more forest than anything else.
What sustainability measures
Sustainability is a measure of the extent to which practices allow for the long-term viability of a system. It generally refers to the responsible maintenance of socio-ecological systems, so that conditions are not diminished for future generations. Every human activity is embedded in some system, and in general, enhancing that system's resilience increases its sustainability.
This is not a coincidence: sustainability is essentially resilience applied over time. A system with strong resilience, the diverse, well-stocked systems described in 1.2, is a system that can keep functioning for future generations without diminishing what it provides. Reduce a system's resilience (smaller storages, less diversity) and you reduce its sustainability by the same logic.
Quick check. A fishing community starts harvesting shellfish and seaweed alongside its usual catch, instead of relying on one species, and builds up a larger communal savings fund for lean years. Has this most likely increased or decreased the community's long-term sustainability?
Three pillars, two different models
Sustainability is generally described as resting on three pillars: environmental, social and economic. How those three pillars relate to each other can be shown with diagrams, and different diagrams imply different things. Weak sustainability models show the three pillars as overlapping circles of roughly equal standing, with sustainability sitting in the overlap. Strong sustainability models instead show the economy nested inside society, and both nested inside the natural environment, implying that the economy and society can only ever be as viable as the environment that contains them.
Weak sustainability: three roughly equal, overlapping pillars. Sustainability exists only where all three overlap.
Environmental sustainability
Environmental sustainability is the use and management of natural resources in a way that allows their replacement, and allows the recovery and regeneration of ecosystems. It covers resource depletion, pollution, and conserving biodiversity. Different resources replace themselves on very different timescales, from a single growing season to millennia.
Social sustainability
Social sustainability focuses on the structures and systems, health, education, equity, community, that support human wellbeing over time. It includes the survival of societies and cultures: the continued use of a language, belief system or spiritual practice within a community.
Economic sustainability
Economic sustainability focuses on the economic structures and systems needed to support production and consumption that will keep meeting human needs into the future. There is a strict dependency here: in terms of the resource use required to meet human needs, there is no economic sustainability without environmental sustainability first.
Sort each real-world action into the pillar it most directly supports.
Bhutan's constitutional requirement to maintain at least 60% forest cover.
A national policy guaranteeing every child access to free public education and healthcare.
A fishery introducing a science-based annual catch quota designed to keep the industry viable for future decades.
Sustainable development
Sustainable development meets the needs of the present without compromising the ability of future generations to meet their own needs. It applies the concept of sustainability specifically to social and economic development: a framework for continuing to develop human civilization while maintaining economic stability, social equity and ecological integrity together. The 1987 Brundtland Report (formally, Our Common Future, from the UN World Commission on Environment and Development) is what introduced the social and economic dimensions of sustainability into this definition, rather than treating sustainability as a purely environmental idea.
Quick check. A country builds new hospitals, schools and reliable electricity access for an underserved region, funded partly by forestry managed so that overall forest cover stays stable rather than shrinking. Does this fit the Brundtland definition of sustainable development?
When unsustainable use collapses a system
Unsustainable use of natural resources can lead directly to ecosystem collapse. The Newfoundland northern cod fishery is the standard case: decades of harvesting beyond the stock's capacity to replace itself ended in one of the most abrupt fisheries collapses on record.
- Spawning biomass fell about 93% in three decades: from roughly 1.6 million tonnes in 1962 to just 72,000-110,000 tonnes by 1992.
- 2 July 1992: Canada declared a moratorium on the northern cod fishery, expected to last about two years.
- It lasted 32 years. Around 19,000 fishing and processing jobs were lost directly, plus roughly 20,000 more indirectly, about 30,000 people, 12% of Newfoundland and Labrador's entire labor force.
- The province's population fell about 10% over the following decade as people left for work elsewhere.
- June 2024: Canada reopened a commercial northern cod fishery with an 18,000-tonne quota, a controversial decision, since government scientists had recommended keeping the moratorium in place. The quota was more than doubled to 38,000 tonnes for 2025.
Sources: Britannica, "Cod fishery collapse of 1992"; Memorial University of Newfoundland Heritage site; CBC News, June 2024; SeafoodSource, 2025.
Chart: via Wikimedia Commons.
Quick check. Government scientists recommended keeping the cod moratorium in place in 2024, but it was reopened anyway. What does this suggest about the 2024 reopening decision?
It shows that reopening was a political and economic judgment made against the specific scientific recommendation, not a decision the science itself concluded was safe. This is a real, live sustainability trade-off, not a settled success story.
Why GDP is a poor sustainability measure
Gross domestic product (GDP), the monetary value of all final goods and services produced and sold in a country over a given period, is the most common indicator of economic development. But GDP neglects the value of natural systems entirely: clear-cutting a forest and selling the timber raises GDP; the forest's lost carbon storage, biodiversity and flood protection do not appear anywhere in the number. Focusing on GDP alone can therefore actively drive unsustainable development. Green GDP is an attempt to correct this: it measures the environmental costs of economic activity and subtracts them from standard GDP.
A rising GDP does not mean a country is becoming more sustainable, and a falling GDP does not mean it is becoming less sustainable. GDP measures the monetary value of economic activity, full stop; it cannot distinguish between activity that depletes natural capital (logging old-growth forest, overfishing a stock to its last viable year) and activity that does not. Bhutan's use of Gross National Happiness instead of GDP as its headline measure exists specifically because of this gap.
Quick check. Country A's GDP rises 4% this year, driven partly by a boom in old-growth logging exports. Country B's GDP falls 1% as it winds down a coal industry while restoring wetlands. Which country's GDP trend is the stronger evidence of increasing sustainability?
Environmental justice
Environmental justice is the right of all people to live in a pollution-free environment, and to have equitable access to natural resources, regardless of race, gender, socio-economic status or nationality. It is why the guiding question for this subtopic pairs sustainable development directly with justice: who bears the costs of environmental harm, and who is denied access to environmental benefits, are rarely distributed evenly.
Photo: U.S. Coast Guard, 2010, public domain, via Wikimedia Commons.
Photo: via Wikimedia Commons.
- 20 April 2010: an explosion on BP's Deepwater Horizon rig killed 11 workers and triggered the largest marine oil spill in US history, in the Gulf of Mexico.
- Gulf fisheries accounted for around 16% of all US domestic seafood landings at the time.
- Federal estimates: up to $952.9 million in lost sales and as many as 9,315 jobs lost across the fishing industry between May and December 2010 alone.
- Research found income loss had a greater long-term psychological health impact on Gulf Coast residents than direct oil exposure itself, effects that persisted for years.
Sources: US Bureau of Ocean Energy Management; NOAA Fisheries; Oceanography journal, Gulf of Mexico Oil Spill and Ecosystem Science special issue.
- June 2022: Tanzania moved to demarcate 1,500 km² of Maasai ancestral land in Loliondo division, Ngorongoro district, as a game reserve.
- The plan threatened the eviction of an estimated 70,000 Maasai people and over 200,000 livestock.
- Roughly 700 security personnel were deployed; forced evictions began 10 June 2022, with at least 30-40 people reported injured by security forces.
- Human rights organizations documented beatings, shootings and arbitrary arrests used against residents who resisted eviction.
Sources: Human Rights Watch, 2023; Amnesty International, 2023; International Work Group for Indigenous Affairs (IWGIA).
Quick check. A new hydroelectric dam displaces a low-income farming community that relied on the river for both water and fish, while the electricity it generates flows to a distant city that never experiences the disruption. Which response best demonstrates environmental justice reasoning about this scenario?
Inequality and access
Inequalities in income, race, gender and cultural identity, within a society and between different societies, produce real disparities in access to water, food and energy. The inability to afford an electricity connection, or the privatization of a community's water source, are both concrete examples: the resource may technically exist, but access to it is not equally distributed.
Quick check. A city has enough treated tap water for every resident, but a private company now runs the water utility and sets connection fees many low-income households cannot afford, so they rely on expensive bottled water instead. Is this primarily a resource scarcity problem or an access inequality problem?
Environmental justice questions expect you to name who specifically is affected and why the burden fell on them rather than someone else, not just describe the environmental harm itself. "Gulf Coast fishing communities lost income disproportionately because their livelihoods depended directly on the specific resource the spill damaged" is a justice-focused answer. "The oil spill damaged the ocean" is not, even though it is true.
Sustainability operates at every scale
Sustainability and environmental justice issues exist at a range of operating scales: individual (personal choices about how to live and work), business, community (religious, cultural, political or Indigenous), city, country (policy, law, socio-economic systems), and global (for example, the UN Sustainable Development Goals). The same underlying issue, unequal water access, an overexploited fishery, can be addressed, or ignored, at any of these scales.
Sustainability indicators
Sustainability indicators are quantitative measures used to track progress: biodiversity, pollution levels, human population, climate change metrics, material and carbon footprints, among others. These can be applied at any scale from local to global, and a single named indicator (a city's air quality index, a country's carbon footprint) is often used to stand in for a system's broader sustainability.
Quick check. A city's air quality index shows pollution levels dropping over five years. A resident cites this as proof that the whole country has become more sustainable. What is the strongest critique of that claim?
Ecological footprints
An ecological footprint is the area of land and water required to sustainably provide all the resources a population consumes, and to absorb all the waste it generates, at its current rate. If a population's footprint is greater than the area or resources actually available to it, that is a direct measure of unsustainability.
Carbon and water footprints
Two footprints are used constantly throughout this course. The carbon footprint measures the greenhouse gases produced by an activity, population or product, expressed in tonnes of carbon dioxide equivalent. The water footprint measures water use, in cubic meters per year. You do not need to know the calculation details behind either, just what each one measures and represents.
Biocapacity
Biocapacity is the capacity of a given biologically productive area to keep generating renewable resources and absorbing the resulting waste. Unsustainability occurs specifically when a population's ecological footprint exceeds the biocapacity available to it.
Bhutan, again. Because of its huge forest cover and small population, Bhutan is one of the few countries whose ecological footprint sits below its biocapacity, giving it an ecological reserve rather than an ecological deficit. Most countries, and the world as a whole, run the opposite way: global footprint has exceeded global biocapacity every year since the early 1970s.
Two real countries, read straight off Global Footprint Network's own accounts, show what reserve and deficit look like over time.
Data: Global Footprint Network, National Footprint and Biocapacity Accounts 2026 edition, CC BY-SA 4.0, via data.footprintnetwork.org.
Indonesia
Data: Global Footprint Network, National Footprint and Biocapacity Accounts 2026 edition, CC BY-SA 4.0, via data.footprintnetwork.org.
Reading a footprint-versus-biocapacity graph like these is common on paper 2, most often under describe or outline. A weak answer just restates what the graph shows in words ("the footprint went up"). A strong one names the overall trend, the direction of each line, and the specific point where the relationship changes, with a year attached. For Indonesia here: footprint stayed below biocapacity from 1961, the two fluctuated against each other through the mid-2000s, and the country entered a sustained ecological deficit in 2007, footprint remaining above biocapacity ever since.
Recent papers have also gotten more creative with this data type: rather than just describing the shape of the graph, a question might ask you to calculate the reserve or deficit at a specific year, reading footprint and biocapacity off the two lines at that point and subtracting one from the other.
This global gap between footprint and biocapacity is exactly what Earth Overshoot Day marks in Topic 8: the calendar date each year when humanity's demand on nature for that year has already exceeded what Earth's biocapacity can regenerate in that same year. Bhutan's ecological reserve is the rare exception to a pattern that, globally, runs the other way.
Quick check. Switzerland has a strong international reputation for environmental policy and clean cities. Its domestic biocapacity is only around 1 global hectare per person, while its ecological footprint runs around 4 global hectares per person. Is Switzerland running an ecological reserve or an ecological deficit?
Citizen science and monitoring
Citizen science plays a role in monitoring Earth's systems and whether resources are being used sustainably. Information gathered by trained volunteers is relevant to local problems and conditions, and can also feed into research on truly global issues, climate change among them.
Topic 3 covers this in more depth: citizen science, government-funded formal surveys, and trained local or Indigenous monitoring (the parabiologist model) each trade off coverage against consistency in different ways when gathering the biodiversity knowledge sustainability decisions depend on.
Quick check. A wildlife app lets thousands of untrained volunteers report animal sightings worldwide, producing far more data points than any government survey team could collect alone. What is the most defensible criticism of this data, compared to a smaller, formally trained monitoring program?
Every sustainability model has limits
There is a range of frameworks and models supporting our understanding of sustainability, and each has both uses and limitations. This should sound familiar: sustainability models are still models, in exactly the sense covered in 1.2, simplified representations of reality, useful precisely because they simplify, but never a complete picture.
Planetary boundaries
Diagram: Azote for Stockholm Resilience Centre, based on Richardson et al. and subsequent updates, via Wikimedia Commons.
Nine processes that have regulated Earth's stability through the Holocene; crossing their limits raises the risk of abrupt, irreversible change. As of the most recent 2025 assessment, 7 of 9 boundaries are judged transgressed.
Uses
- Science-based limits on human disturbance
- Broadens focus beyond climate change alone
- Alerts policymakers to urgent Earth-system risk
Limitations
- Focuses on ecology, not environmental justice
- A work in progress as data improves
- Global boundaries may not guide local action well
Doughnut economics
Diagram: Kate Raworth / Doughnut Economics Action Lab, CC BY-SA 4.0, via Wikimedia Commons.
Kate Raworth's model: a social foundation (based on the SDGs) as the inner ring, an ecological ceiling (based on planetary boundaries) as the outer ring. The "safe and just space for humanity" is the doughnut between them.
Uses
- Combines ecological and social elements together
- Reached popular and policy awareness
- Applied at scales from cities to whole countries
Limitations
- Still a work in progress in application
- States broad principles, not specific policies
UN Sustainable Development Goals
17 goals and targets guiding global action on sustainability and environmental justice, addressing poverty, inequality, climate, degradation, prosperity, and peace and justice.
Uses
- Sets common ground for policymaking
- Applies to developed and developing countries alike
- Galvanizes international action on inequality
Limitations
- Goals arguably do not go far enough
- Top-down and bureaucratic in practice
- Tends to ignore local context; data can be lacking
Circular economy
Three principles: eliminate waste and pollution, circulate products and materials, regenerate nature. Contrasts with the linear "take, make, waste" model. The Ellen MacArthur Foundation's butterfly diagram is its standard illustration.
Uses
- Regenerates natural systems, cuts emissions
- Strengthens local food networks and communities
- Extends product life, reduces waste
Limitations
- Low consumer and company awareness
- Weak recycling enforcement; some waste isn't recyclable
- Financing gaps for circular business models
When asked to evaluate a named sustainability framework, always give at least one use and one limitation, and be specific rather than generic. "It has limitations" earns nothing; "it is a work in progress, boundary assessments change as new data becomes available" does. Naming the framework correctly (SDGs, planetary boundaries, doughnut economics, circular economy) also matters: they are frequently confused with each other in exam answers because they address overlapping ground.
Each of these scenarios describes one framework in action. Identify which one before checking.
A research team reports that seven of the nine Earth-system processes they track have now moved past the safe limit that has held since before the industrial era.
A national economics ministry plots its development plan on a diagram with two rings: an inner ring it must stay above to meet people's basic needs, and an outer ring it must stay below to avoid ecological breakdown.
A furniture manufacturer redesigns its products so that at the end of a chair's life, every material in it can be recovered and fed back into making a new one, rather than sent to landfill.
A city compares its progress on poverty, clean water and climate action against 16 other goals, using a shared framework that lets it benchmark itself against cities in other countries.
Choosing a framework
A mid-sized coastal city wants to set a 10-year sustainability strategy. City planners are deciding whether to organize it around the UN SDGs, the doughnut economics model, or a circular economy plan for the city's waste and manufacturing sector.
Think it through, then check your reasoning against the model answer below. Recommend one framework as the primary organizing model for the city's strategy, and justify your choice by naming at least one real strength and one real limitation of the framework you picked.
- Any of the three frameworks can be justified; what matters is a specific, accurate strength and limitation, not the choice itself.
- Doughnut economics example: strength, it explicitly unites social floor and ecological ceiling in one visual model, useful for a city balancing resident wellbeing against environmental limits; limitation, it does not specify concrete city policies on its own, so the city would still need to translate it into action.
- Circular economy example: strength, directly actionable for a city's waste and manufacturing sector, with a clear "eliminate, circulate, regenerate" structure; limitation, depends on consumer and company buy-in and enforcement capacity the city may not have.
- SDG example: strength, gives the city a globally recognized, comparable framework it can report progress against; limitation, the SDGs are broad and global, and may not translate cleanly to city-specific priorities without significant adaptation.
- A strong answer explicitly weighs the trade-off rather than presenting the chosen framework as flawless.
- Bhutan forest cover, carbon balance and GNH: World Bank Blogs, 2025; Climate Council; National Geographic; Harvard International Review.
- Northern cod stock decline, moratorium and 2024-2025 reopening: Britannica; Memorial University of Newfoundland Heritage website; CBC News, June 2024; SeafoodSource, 2025.
- Deepwater Horizon socioeconomic impacts: US Bureau of Ocean Energy Management; NOAA Fisheries; Oceanography journal special issue on the Gulf oil spill.
- 2022 Loliondo, Tanzania Maasai evictions: Human Rights Watch, 2023; Amnesty International, 2023; International Work Group for Indigenous Affairs.
- Planetary boundaries status (7 of 9 transgressed): Stockholm Resilience Centre and Potsdam Institute, Planetary Health Check, September 2025.
- World forest cover (31% of land area): FAO, Global Forest Resources Assessment 2020. Suriname forest cover and carbon-negative status: World Bank; Rewild; the Carbon Negative Alliance (Bhutan, Suriname, Panama), formed 2021.
- Brazil and Indonesia biocapacity/footprint figures: Global Footprint Network, National Footprint and Biocapacity Accounts 2026 edition, CC BY-SA 4.0, via data.footprintnetwork.org.
- Switzerland biocapacity and ecological footprint figures: Global Footprint Network, Switzerland Fact Sheet, 2024 data.
- Photos and diagrams: via Wikimedia Commons, individually credited beneath each image.
- IB Environmental Systems and Societies Guide, first assessment 2026, Topic 1, Subtopic 1.3, statements 1.3.1-1.3.21.
Estimate your own ecological footprint
Application of skills, statement 1.3.13: use footprint calculators to establish your own ecological, carbon or water footprint, and present comparative data graphically. This simplified calculator illustrates the idea: adjust each slider to a rough estimate of your own habits, and see how your combined footprint compares to two real benchmarks.
Challenge: try to bring your combined footprint below the one-planet target line. Notice which single choice moves the bar the most.
Adjust the sliders to see your estimate.
For your actual 1.3.13 submission, use a real calculator. The slider above is a teaching illustration built for this page; footprintcalculator.org runs Global Footprint Network's own methodology and gives you a real gha-per-person result, the kind you can cite and graph properly.
A real footprint calculator would output a value in global hectares (gha) per person, comparable directly to biocapacity per person (about 1.5-1.6 gha available globally) and to a one-planet target (living within that share). Once you have your own number, or your class's spread of numbers, present it as a bar chart in spreadsheet software, one bar per person or per lifestyle factor, exactly as 1.3.13's application of skills requires.
- Global biocapacity and one-planet benchmark figures are illustrative, based on published Global Footprint Network estimates of global biocapacity per capita.
- Real calculator: footprintcalculator.org, Global Footprint Network.
- IB Environmental Systems and Societies Guide, first assessment 2026, Topic 1, Subtopic 1.3, statement 1.3.13.
Glossary
- Sustainability
- A measure of the extent to which practices allow for the long-term viability of a system, without diminishing conditions for future generations.
- Weak sustainability
- A model showing environmental, social and economic pillars as overlapping circles of roughly equal standing.
- Strong sustainability
- A model showing the economy nested inside society, and both nested inside the environment.
- Sustainable development
- Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
- Gross domestic product (GDP)
- The monetary value of final goods and services produced and sold by a country in a given period; does not account for the value of natural systems.
- Green GDP
- A modified GDP measure that subtracts the environmental costs of economic activity.
- Environmental justice
- The right of all people to a pollution-free environment and equitable access to natural resources, regardless of race, gender, socio-economic status or nationality.
- Sustainability indicator
- A quantitative measure, such as biodiversity, pollution or carbon footprint, used to track sustainability at any scale.
- Ecological footprint
- The area of land and water required to sustainably provide all resources a population consumes and absorb all its waste.
- Carbon footprint
- The greenhouse gases produced by an activity, population or product, measured in tonnes of CO2 equivalent.
- Water footprint
- A measure of water use, in cubic meters per year.
- Biocapacity
- The capacity of a biologically productive area to generate renewable resources and absorb waste on an ongoing basis.
- Ecological deficit / reserve
- The condition where a population's ecological footprint exceeds (deficit) or sits below (reserve) the biocapacity available to it.
- UN Sustainable Development Goals (SDGs)
- Seventeen social and environmental goals guiding global action on sustainability and environmental justice.
- Planetary boundaries
- A model of nine Earth-system processes whose limits, if crossed, raise the risk of abrupt, irreversible change.
- Doughnut economics
- Kate Raworth's model of a social foundation and an ecological ceiling defining a safe and just space for humanity between them.
- Circular economy
- An economic model built on eliminating waste, circulating products and materials, and regenerating nature, in contrast to a linear take-make-waste model.
The questions and markschemes below attempt to mimic IB wording, phrasing and expectations, but are not IB-written questions.
Quick quiz
Score: 0 / 5
1. A diagram showing the economy nested inside society, nested inside the environment, illustrates:
2. What does GDP fail to account for?
3. Unsustainability occurs specifically when:
4. The doughnut economics model's outer ring (ecological ceiling) is based on:
5. Which best describes environmental justice?
Written practice questions
Total score: 0 / 20
Calculate how many percentage points Bhutan’s actual forest cover is above its constitutional minimum.
Check each point your answer covers:
Accept 12.3 percentage points.
Do not accept only 12.3% increase, unless the student’s working clearly shows subtraction in percentage points.
Your score: 0 / 1
Calculate Bhutan’s net annual carbon dioxide balance using the figures for forest sequestration and national emissions.
Check each point your answer covers:
Accept −7 million tonnes CO2 per year / absorbs 7 million tonnes more CO2 than it emits.
Your score: 0 / 1
Outline two ways Bhutan may be considered environmentally sustainable.
Check each point your answer covers:
Do not accept only “Bhutan is sustainable” without a specific supporting reason.
Your score: 0 / 2
Explain why Gross National Happiness may be a more appropriate development measure than GDP for assessing sustainability.
Check each point your answer covers:
Do not accept only “GNH measures happiness” without linking to sustainability.
Your score: 0 / 3
Explain how unsustainable harvesting can lead to fishery collapse.
Check each point your answer covers:
Do not accept only “too many fish are caught” without linking to replacement/reproduction/collapse.
Your score: 0 / 3
Discuss whether reopening the northern cod fishery with a quota is likely to be sustainable.
Check each point your answer covers:
Arguments that it may be sustainable [3 max]
Arguments that it may not be sustainable [3 max]
Conclusion/judgment [1 max]
Award [3 max] for arguments. Reserve [1] for a supported judgment.
Do not credit a conclusion if only one side has been considered.
Your score: 0 / 4
Distinguish between GDP and Green GDP.
Check each point your answer covers:
Do not accept only “Green GDP is better” without explaining how.
Your score: 0 / 2
Explain why an ecological footprint greater than biocapacity indicates unsustainability.
Check each point your answer covers:
Do not accept only “the footprint is bigger” without explaining why this is unsustainable.
Your score: 0 / 2
Outline one advantage and one limitation of using citizen science to monitor sustainability.
Check each point your answer covers:
Advantage [1 max]
Limitation [1 max]
Award [1] for one valid advantage and [1] for one valid limitation.
Do not award both marks for two advantages or two limitations.
Your score: 0 / 2
To what extent is GDP a useful measure of sustainable development?
Essays like this are marked holistically against markbands, not ticked off point by point. Read the sections below, then rate your own answer against the bands.
Answers may demonstrate
- understanding of concepts and terminology such as GDP, Green GDP, sustainable development, sustainability, environmental sustainability, social sustainability, economic sustainability, natural capital, ecosystem services, ecological footprint, biocapacity, carbon footprint, resource depletion, pollution, wellbeing, equity and environmental justice;
- breadth in addressing and linking a range of factors that influence whether GDP is useful for measuring sustainable development, including economic output, jobs, income, production, consumption, natural resource use, pollution, biodiversity loss, ecosystem services, human wellbeing, inequality and future generations;
- examples of why GDP may be useful, such as indicating economic activity, employment opportunities, government revenue, infrastructure development or capacity to invest in health, education, conservation or clean technology;
- examples of why GDP may be misleading, such as clear-cutting forests increasing GDP while reducing carbon storage, biodiversity and flood protection; overfishing increasing short-term income while reducing fish stocks; or pollution clean-up increasing GDP after environmental damage;
- understanding that sustainable development includes environmental, social and economic dimensions, so GDP alone cannot fully measure sustainability;
- balanced analysis of GDP’s strengths as a simple, comparable economic indicator and its limitations as a sustainability indicator;
- evaluation of alternatives or complements such as Green GDP, Gross National Happiness, ecological footprint, biocapacity, carbon footprint, water footprint, sustainability indicators or environmental justice measures;
- a conclusion that is consistent with, and supported by, the analysis and examples given, for example: GDP is useful for measuring economic activity, which is one part of sustainable development, but it is not a sufficient measure of sustainability because it ignores environmental degradation, natural capital, wellbeing and equity; therefore GDP should be used only alongside environmental and social indicators.
Indicative content
- GDP is widely used and allows comparison of economic activity between countries or over time.
- Higher GDP may indicate greater capacity to fund infrastructure, education, healthcare or environmental management.
- Economic sustainability is one pillar of sustainable development.
- However, GDP does not measure whether natural resources are being depleted.
- GDP can rise when forests are logged, fish stocks are overharvested or pollution is cleaned up.
- GDP does not subtract lost ecosystem services such as carbon storage, biodiversity, soil protection, water purification or flood protection.
- GDP does not measure social wellbeing, culture, equity or environmental justice.
- GDP may encourage short-term economic growth at the expense of long-term sustainability.
- Green GDP tries to correct this by subtracting environmental costs.
- GNH may be broader because it includes wellbeing, culture and environmental conservation.
- Footprint/biocapacity data can show whether resource use exceeds regenerative capacity.
Markbands
The response shows limited understanding of GDP or sustainable development. The answer may describe GDP generally without linking it clearly to sustainability. Examples may be absent, vague or inaccurate. The response may be one-sided, with little or no consideration of both usefulness and limitations. There is little or no supported judgment on “to what extent.”
The response shows sound understanding of GDP and sustainable development. There is some explanation of why GDP may be useful as an economic indicator. There is some explanation of why GDP is limited as a sustainability indicator. At least one relevant example is used. There is some reference to environmental and/or social dimensions of sustainability. The response includes some judgment, although it may be uneven or only partly supported.
The response gives a balanced and well-developed evaluation of GDP as a measure of sustainable development. It clearly explains GDP’s usefulness for measuring economic activity and its limitations for measuring environmental and social sustainability. It uses relevant examples effectively. It evaluates alternatives or complementary indicators such as Green GDP, GNH, ecological footprint, biocapacity, carbon footprint or environmental justice indicators. It recognizes that sustainable development requires economic, social and environmental dimensions together. There is a clear and supported conclusion that directly answers “to what extent.”
Self-assessed band: not yet rated
- Written practice questions and markschemes reproduced from a set of selected IB ESS 1.3 Sustainability questions and markschemes: Bhutan and sustainability; the Newfoundland cod fishery; GDP, Green GDP and sustainability; ecological footprint and biocapacity; citizen science and sustainability monitoring; and a GDP essay.
- IB Environmental Systems and Societies Guide, first assessment 2026, Topic 1, Subtopic 1.3, statements 1.3.1-1.3.21.