The Earth Summit, Sustainable Development and the Global Commons (Class 12 Political Science)
Updated 16 October 2026 · Fact-checked
The United Nations Conference on Environment and Development at Rio de Janeiro in June 1992, the Earth Summit, put environmental issues at the centre of world politics. Attended by 170 states, it produced conventions on climate change, biodiversity and forestry, recommended Agenda 21, and agreed on sustainable development: combining economic growth with ecological responsibility.
Notice that sustainable development joins economic growth with ecological care, and Rio 1992 produced four outcomes: two conventions, forest principles and Agen
Illustration drawn for QuestionBuddy.
Understand The Earth Summit and Sustainable Development
Why this topic matters. The opening sections of Chapter 6 explain why the environment is a political issue, what the 1992 Earth Summit achieved, and what the global commons are. Board papers test these through 1-mark statement items, 2-mark 'name four global commons' questions and 4-mark evaluations of global efforts. NCERT sections: 'Environmental concerns in global politics' and 'The protection of global commons', with the Antarctica box.
1. The problems on the table.
- Cultivable land is barely expanding, and much existing farmland is losing fertility; grasslands are overgrazed and fisheries over-harvested.
- Water bodies are depleted and polluted. The UNDP Human Development Report 2016 says 663 million people in developing countries lack safe water and 2.4 billion lack sanitation, causing the death of more than three million children a year.
- Natural forests are being cut, biodiversity is being lost, the ozone layer is thinning (the 'ozone hole'), and coastal waters are being polluted mainly by land-based activity.
- NCERT's margin example: around the Aral Sea, toxic water destroyed fishing, shipping collapsed and salty soil cut crop yields, forcing thousands to leave.
2. Why these are political, not just geography.
| Reason | Explanation |
|---|---|
| Government action has political consequences | Steps to check degradation affect people and interests |
| No single government can solve them | So they become part of world politics |
| Questions of power | Who causes degradation, who pays, who must repair it, who uses how much of the Earth's resources |
3. How the issue rose: a timeline.
| Year | Event |
|---|---|
| 1960s onwards | Environmental consequences of growth acquire a political character |
| 1972 | The Club of Rome, a global think tank, publishes *Limits to Growth*, warning of resource depletion as population rises |
| From then | UNEP and other agencies hold conferences and promote studies for a coordinated response |
| 1987 | Brundtland Report, *Our Common Future*: traditional growth patterns are not sustainable in the long run, especially as the South demands more industrial development |
| June 1992 | UN Conference on Environment and Development, Rio de Janeiro (Earth Summit): 170 states, thousands of NGOs, many MNCs |
4. The Earth Summit: two agendas.
| Global North (rich, developed) | Global South (poor, developing) |
|---|---|
| Concerned with ozone depletion and global warming | Concerned with the link between economic development and environmental management |
Outcomes: conventions on climate change, biodiversity and forestry; a recommended list of development practices called Agenda 21; and a consensus on sustainable development, combining economic growth with ecological responsibility.
Limits: differences were left unresolved; the question was how to achieve sustainability; some critics said Agenda 21 leaned towards economic growth rather than ecological conservation.
5. The global commons.
- 'Commons' are resources owned by no one but shared by a community: a common room, a park, a river.
- Areas outside the sovereign jurisdiction of any one state need common governance by the international community. They are called *res communis humanitatis* or global commons: the earth's atmosphere, Antarctica, the ocean floor and outer space.
- Landmark agreements: 1959 Antarctic Treaty, 1987 Montreal Protocol, 1991 Antarctic Environmental Protocol.
- Why cooperation is hard: consensus is difficult when scientific evidence and time frames are vague; the discovery of the ozone hole over the Antarctic in the mid-1980s showed both the opportunity and the dangers.
- North-South inequality: in outer space, as with the atmosphere and the ocean floor, the key issue is technology and industrial development, so the benefits of exploiting it are far from equal.
6. Antarctica box.
| Fact | Figure |
|---|---|
| Continental area | Over 14 million sq km, plus 36 million sq km of ocean |
| Share of world's wilderness | 26 per cent |
| Terrestrial ice / planetary fresh water | 90 per cent / 70 per cent |
| Rival views | UK, Argentina, Chile, Norway, France, Australia, New Zealand claim sovereignty; most states treat it as a global commons |
| Since 1959 | Activities limited to scientific research, fishing and tourism; even so, parts are degraded by waste from oil spills |
Deep ice cores record greenhouse gas levels and temperatures from long ago, and krill sits at the centre of its marine food chain.
Key quotations
Short lines worth knowing by heart: who says them, when, and why they matter.
Most of them are such that no single government can address them fully
NCERT, Contemporary World Politics, Chapter 6: Explaining why environmental problems belong to world politics.
The core argument for treating the environment as a global political issue.
combining economic growth with ecological responsibility
NCERT, Chapter 6: The consensus reached at the Rio Summit.
NCERT's working definition of sustainable development.
Agenda 21 was biased in favour of economic growth
NCERT, Chapter 6, reporting critics: Assessment of the Rio outcomes.
Use it for the 'limits of Rio' part of an evaluation.
The Earth Summit and Sustainable Development: key facts
- Timeline
1960s environment politicised 1972 Club of Rome, Limits to Growth 1987 Brundtland Report, Our Common Future June 1992 Earth Summit, Rio de Janeiro - UNEP organised conferences and studies in between.
- Rio outcomes
- 170 states, thousands of NGOs, many MNCs
- Conventions: climate change, biodiversity, forestry
- Agenda 21
- Consensus on sustainable development
- Critics: Agenda 21 favoured growth over conservation.
- North vs South at Rio
- North: ozone depletion, global warming | South: economic development and environmental management
- The root of later disputes on responsibility.
- Global commons
- Earth's atmosphere
- Antarctica
- Ocean floor
- Outer space
- Treaties: Antarctic Treaty 1959, Montreal Protocol 1987, Antarctic Environmental Protocol 1991
- Outside the sovereign jurisdiction of any one state.
How to answer The Earth Summit and Sustainable Development questions
Questions ask why the environment is political, what Rio produced, what sustainable development means, what the global commons are and why protecting them is hard. Precision on years and lists earns the marks; evaluation needs the North-South angle.
- 1Define the term first: Earth Summit, sustainable development or global commons.
- 2Give the date, place and attendance for Rio (June 1992, Rio de Janeiro, 170 states).
- 3List outcomes as separate points: three conventions, Agenda 21, sustainable development.
- 4For 'why political', use NCERT's power questions: who causes, who pays, who repairs, who uses.
- 5For global commons, name all four and one treaty, then explain the consensus and North-South problems.
- 6In 4- and 6-mark evaluations, end with the limits: unresolved differences and the critique of Agenda 21.
The Earth Summit and Sustainable Development in real life
The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.
Environment as a question of power
Suppose smoke from brick kilns in one district blows into a neighbouring district, where children fall ill and crops wither. The kiln owners say they provide jobs; the neighbouring district wants compensation and a ban.
Which questions does this raise that make environmental issues political?
Try it first, then show the solutionSolution
- Who caused the damage? The kiln district.
- Who pays the price? The neighbouring district's families and farmers.
- Who must act, and who gets to use the shared air? These must be settled by negotiation and rules, not by one side alone.
Answer: It raises NCERT's questions of who causes degradation, who pays for it, who is responsible for taking corrective action and who gets to use how much of a shared resource; that is why the environment belongs to politics.
Memory hook: Who pollutes, who pays, who repairs?
Sustainable development
Imagine a village panchayat that wants a new factory for jobs but depends on a lake that the factory's waste could poison. Elders want the lake protected; young people want work.
What would the Rio idea of sustainable development advise?
Try it first, then show the solutionSolution
- Accept that growth (jobs) is needed.
- Accept that the lake is a resource future generations need.
- Combine both: allow the factory only with waste treatment and limits.
Answer: Combine economic growth with ecological responsibility instead of choosing one over the other.
Memory hook: Grow, but don't poison the well.
Tricks to remember The Earth Summit and Sustainable Development
Short memory aids. Say each one aloud once, then use it on a question the same day.
72-87-92
Club of Rome 1972, Brundtland 1987, Rio 1992: the environment's road to the summit, five years before Rio came Brundtland.
Use it when: Chronology questions.
A-A-O-O
Atmosphere, Antarctica, Ocean floor, Outer space: the four global commons.
Use it when: Name-four questions.
C-B-F + 21
Rio gave Climate, Biodiversity and Forestry conventions plus Agenda 21.
Use it when: Outcomes of the Earth Summit.
The Earth Summit and Sustainable Development: solved examples
Ordered from board level to HOTS. Try each one before you open the solution.
Example 1: Brundtland's warning · 1 mark · MCQBoard level
The 1987 Brundtland Report warned that:
(a) the ozone layer had fully recovered
(b) traditional patterns of economic growth were not sustainable in the long term
(c) developing countries should stop industrialising
(d) Antarctica should be divided among seven states
Try it first, then show the solutionSolution
- NCERT: the report warned that traditional patterns of economic growth were not sustainable in the long term, especially given the South's demand for more industrial development (1 mark).
Answer: (b) traditional patterns of economic growth were not sustainable in the long term
Example 2: Two outcomes of Rio · 2 marks · Very short answerBoard level
State any two outcomes of the 1992 Earth Summit. (2 marks)
Try it first, then show the solutionSolution
- Any two: conventions on climate change, biodiversity, forestry; Agenda 21; consensus on sustainable development (1 + 1 marks).
Answer: (i) It produced conventions dealing with climate change, biodiversity and forestry. (ii) It recommended a list of development practices called Agenda 21 and reached a consensus on sustainable development, that is, combining economic growth with ecological responsibility.
Example 3: Assertion and reason: global commons · 1 mark · Assertion-reasonHarder board level
Assertion (A): Protecting the global commons requires governance by the international community.
Reason (R): No single state has sovereign control over areas such as Antarctica or outer space.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Try it first, then show the solutionSolution
- No single state owns them, so no single state can govern them (1 mark).
Answer: (a) Both A and R are true and R is the correct explanation of A.
Example 4: Why environment is political · 4 marks · Short answerHarder board level
Explain why environmental issues are treated as part of world politics. (4 marks)
Try it first, then show the solutionSolution
- Government action has political consequences (1 mark).
- No single government can solve them; cross-border nature (1 mark).
- Questions of power: who causes, pays, repairs, uses (1 mark).
- Rise since 1960s; Rio 1992 consolidated it (1 mark).
Answer: First, when governments act to check degradation such as soil loss, water pollution or deforestation, their decisions affect interests and people, so the issues have political consequences. Second, most of these problems, such as ozone depletion or coastal pollution, cannot be solved fully by any single government, so they must be handled through international cooperation. Third, they raise questions of power: who causes degradation, who pays the price, who must take corrective action and who gets to use how much of the Earth's resources. Finally, from the 1960s the environmental cost of growth became a political concern, highlighted by the Club of Rome's Limits to Growth (1972) and UNEP conferences, and the 1992 Earth Summit at Rio firmly placed the environment in global politics.
Example 5: Source-based: the Antarctic · 4 marks · Source-basedHarder board level
Read the passage (written for this page) and choose the most appropriate answer for each question.
A frozen continent holds most of the world's land ice and a large share of its fresh water. Several countries claim parts of it, while most other states say it belongs to no one. For decades only limited activities have been allowed there, yet oil spills have still left waste in some places. Scientists drill deep into its ice to study the distant past.
(i) The Antarctic continental region extends over about:
(A) 1.4 million sq km (B) 14 million sq km (C) 36 million sq km (D) 140 million sq km
(ii) Which of the following countries does NOT claim sovereign rights over Antarctic territory?
(A) Argentina (B) Norway (C) India (D) Chile
(iii) Deep ice cores from Antarctica are valuable because they:
(A) contain oil reserves (B) provide information about greenhouse gas concentrations and atmospheric temperatures of long ago (C) are used for drinking water in the South (D) show the borders of the claimant states
(iv) The damage from oil spills despite limited activity shows that the global commons:
(A) need no rules (B) need continuing common governance and monitoring (C) should be divided among claimant states (D) are not affected by human activity
Try it first, then show the solutionSolution
- (i) (B): over 14 million sq km, plus 36 million sq km of ocean (1 mark).
- (ii) (C): the claimants are the UK, Argentina, Chile, Norway, France, Australia and New Zealand (1 mark).
- (iii) (B): ice cores record past greenhouse gases and temperatures (1 mark).
- (iv) (B): even limited activity causes harm, so common governance is needed (1 mark).
Answer: (i) (B) 14 million sq km; (ii) (C) India; (iii) (B) provide information about greenhouse gas concentrations and atmospheric temperatures of long ago; (iv) (B) need continuing common governance and monitoring.
Example 6: Long answer: evaluate the Earth Summit · 6 marks · Long answerHOTS / competency
"The Earth Summit of 1992 was a landmark, but it left the hardest questions unanswered." Evaluate. (6 marks)
Try it first, then show the solutionSolution
- Background and scale: Rio, June 1992, 170 states (1 mark).
- Achievements: conventions, Agenda 21, sustainable development (2 marks).
- Unanswered questions: North-South agendas, how to achieve sustainability, Agenda 21 critique (2 marks).
- Judgement (1 mark).
Answer: The UN Conference on Environment and Development at Rio de Janeiro in June 1992 was attended by 170 states, thousands of NGOs and many multinational corporations. Coming five years after the Brundtland Report warned that traditional growth was unsustainable, it firmly consolidated the environment as an issue of global politics.
Its achievements were real. It produced conventions dealing with climate change, biodiversity and forestry; it recommended Agenda 21, a list of development practices; and it reached a consensus on sustainable development, combining economic growth with ecological responsibility. The Rio Declaration also accepted that states have common but differentiated responsibilities.
But the hardest questions remained open. The North was mainly concerned with ozone depletion and global warming, while the South wanted to address the link between development and environmental management. Everyone agreed on sustainable development, yet there was no agreement on how exactly it was to be achieved, and some critics argued that Agenda 21 favoured economic growth over ecological conservation.
So the statement is fair. Rio set the agenda and the vocabulary of global environmental politics, but because it could not settle who should do how much, later negotiations, such as those on emission cuts, kept returning to the North-South divide.
Where students lose marks in The Earth Summit and Sustainable Development
The slips examiners see most often, and what to write instead.
Mistake: Wrong venue or year
Confusing Rio with Kyoto or Montreal.
Wrong working
The Earth Summit was held at Kyoto in 1997.
Right working
Rio de Janeiro, Brazil, June 1992; Kyoto (1997) is the protocol.
Do this: Rio = Summit; Kyoto = Protocol; Montreal = ozone.
Usually costs: 1 mark.
Mistake: Listing a national resource as a global commons
Mixing local commons with global commons.
Wrong working
The Himalayas and the Ganga are global commons.
Right working
Atmosphere, Antarctica, ocean floor, outer space: outside any state's jurisdiction.
Do this: Test: does any one country have sovereignty over it?
Usually costs: 1-2 marks.
Mistake: Defining sustainable development vaguely
Writing 'saving nature' only.
Wrong working
Sustainable development means stopping development to protect nature.
Right working
Combining economic growth with ecological responsibility.
Do this: Always mention both growth and ecology.
Usually costs: 1 mark.
Mistake: Only praising Rio
Ignoring its limits in evaluation questions.
Wrong working
The Earth Summit solved global environmental problems.
Right working
Landmark outcomes, but unresolved North-South differences and Agenda 21 critique.
Do this: Balance achievements with limits.
Usually costs: Quality marks.
Exam tips
- Asked in: 2023 board paper 59/1/1 Q5 (1 mark, correct statements about the environment and the Rio conference); 2026 board paper 59/3/1 Q3 (1 mark, what sustainable development emphasises); 2026 board paper 59/4/1 Q6 (1 mark, true statement about the global commons) and Q14 (2 marks, name four global commons); 2025 board paper 59/5/1 Q14 (2 marks, four elements of the global commons); 2026 board paper 59/3/1 Q23 (4 marks, why global efforts have fallen short, or efforts towards the Rio Declaration). Answers here are our own.
- Learn the four global commons as a fixed set.
- Pair every Rio answer with the North-South contrast.
- Quote NCERT's definition of sustainable development word for word.
- Keep Kyoto, CBDR and India's stand for the next topic unless the question asks for them.
Practice questions on The Earth Summit and Sustainable Development
Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.
Q1 · 1 mark · MCQBoard level
Which of the following was NOT an outcome of the 1992 Earth Summit?
(a) A convention on biodiversity
(b) Agenda 21
(c) Binding emission targets for industrialised countries
(d) A convention on climate changeHint
Emission targets came with a later protocol.
Answer
(c) Binding emission targets for industrialised countries came later, with the 1997 Kyoto Protocol.
Q2 · 2 marks · Very short answerBoard level
Why is the status of Antarctica disputed? (2 marks)
Hint
Two claims.
Answer
Some countries, namely the UK, Argentina, Chile, Norway, France, Australia and New Zealand, have made legal claims to sovereign rights over Antarctic territory. Most other states hold that it is part of the global commons and not subject to the exclusive jurisdiction of any state.
Q3 · 2 marks · Very short answerHarder board level
How did the agendas of the global North and the global South differ at the Rio Summit? (2 marks)
Hint
Ozone and warming vs development.
Answer
The rich countries of the North were mainly concerned with ozone depletion and global warming, while the developing countries of the South wanted to address the relationship between economic development and environmental management.
Q4 · 1 mark · Assertion-reasonHarder board level
Assertion (A): Cooperation over the global commons has been easy because all states share the same interests.
Reason (R): Agreements such as the 1959 Antarctic Treaty and the 1987 Montreal Protocol have been signed.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.Hint
NCERT calls cooperation 'not easy'.
Answer
(d) A is false but R is true: the agreements exist, but consensus is hard because of vague evidence and North-South inequality.
Q5 · 4 marks · Short answerHarder board level
Why is it difficult to manage the global commons? Explain with two reasons. (4 marks)
Hint
Consensus; North-South; technology.
Answer
First, it is hard to reach consensus on common environmental agendas when the scientific evidence and time frames are vague; the discovery of the ozone hole over the Antarctic in the mid-1980s showed both the opportunity and the danger in acting on global problems. Second, management is shaped by North-South inequality: in outer space, as with the atmosphere and the ocean floor, the crucial factor is technology and industrial development, so the benefits of exploiting these areas go mainly to technologically advanced countries and are far from equal for present and future generations. Rival claims, as over Antarctica, add a third difficulty.
Q6 · 4 marks · Short answerHOTS / competency
Suppose a powerful industrial country proposes to mine the ocean floor near Antarctica, arguing that since no state owns it, anyone with the technology may use it. Using NCERT, argue against this proposal. (4 marks)
Hint
Global commons; North-South inequality; Antarctic fragility.
Answer
First, the ocean floor and Antarctica are global commons, res communis humanitatis: precisely because no state has sovereign jurisdiction, they require common governance by the international community, not use by whoever arrives first. Second, NCERT notes that in such areas the crucial factor is technology and industrial development, so 'first come, first served' would send the benefits to technologically advanced countries and leave present and future generations elsewhere with little; the proposal deepens North-South inequality. Third, the Antarctic is ecologically fragile: since 1959 activity there has been limited to research, fishing and tourism, yet even these have caused degradation through oil spills. Agreements such as the 1959 Antarctic Treaty and the 1991 Antarctic Environmental Protocol show that the international community has chosen shared rules over unilateral use.
Q7 · 6 marks · Long answerHOTS / competency
Examine the rise of environmental concerns in global politics from the 1960s to the Earth Summit of 1992. (6 marks)
Hint
Club of Rome, UNEP, Brundtland, Rio.
Answer
Environmental concerns are old, but from the 1960s the environmental consequences of economic growth took on a political character. In 1972 the Club of Rome, a global think tank, published Limits to Growth, which dramatised the possible depletion of the Earth's resources as population grew rapidly. International agencies, including the UN Environment Programme, then began organising conferences and detailed studies to coordinate responses, and the environment emerged as a significant issue of global politics.
In 1987 the Brundtland Report, Our Common Future, warned that traditional patterns of growth could not be sustained in the long term, especially as the South demanded further industrial development. This set the stage for the UN Conference on Environment and Development at Rio de Janeiro in June 1992, the Earth Summit, attended by 170 states, thousands of NGOs and many MNCs.
Rio produced conventions on climate change, biodiversity and forestry, recommended Agenda 21 and accepted sustainable development as the goal. Yet it also exposed the divide: the North stressed ozone depletion and global warming, the South the link between development and environment, and critics felt Agenda 21 favoured growth. By 1992, therefore, the environment was firmly part of world politics, but as a contested rather than settled issue.
Test your recall
Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.
1.According to the UNDP Human Development Report 2016 cited by NCERT, how many people in developing countries have no access to safe water?Show answer
663 million (and 2.4 billion have no access to sanitation).
2.What happened around the Aral Sea, in NCERT's example?Show answer
Toxic waters destroyed the fishing industry, shipping and all related activities collapsed, and thousands of people had to leave their homes.
3.Which 1991 agreement concerns the protection of the Antarctic environment?Show answer
The Antarctic Environmental Protocol.
4.Which tiny marine creature is central to the Antarctic food chain?Show answer
Krill.
5.What share of planetary fresh water does the Antarctic represent?Show answer
70 per cent (and 90 per cent of all terrestrial ice).
6.When was the ozone hole over the Antarctic discovered?Show answer
In the mid-1980s.
The Earth Summit and Sustainable Development: frequently asked questions
Who attended the Earth Summit besides states?
Thousands of NGOs and many multinational corporations, alongside 170 states.
What is Agenda 21?
A list of development practices recommended by the Rio Summit; critics said it favoured economic growth over ecological conservation.
Did everyone at Rio agree on how to achieve sustainable development?
No. There was consensus on combining economic growth with ecological responsibility, but not on how exactly to achieve it, and some critics said Agenda 21 favoured growth over conservation.
Why do the benefits of outer space not reach all countries equally?
Because, as with the atmosphere and the ocean floor, the crucial factor is technology and industrial development, so technologically advanced countries gain far more.