These quick revision notes compress the Environmental Law principles, statutes, conventions and judgments CLAT PG has tested into one-line points. CLAT PG 2027 is on 6 December 2026, and the paper's Environmental Law questions sit under passages drawn from recent Supreme Court judgments. Start with the weightage table, then revise the principles, because every passage turns on one of them.
How much weightage does Environmental Law carry in CLAT PG?
It varies: Environmental Law has carried between 0 and 10 questions per paper, with 5 - 10 questions in each paper since 2024.
CLAT PG has 120 one-mark questions, and each wrong answer costs 0.25 marks. The table counts questions classified as Environmental Law; climate-treaty passages are sometimes counted under Public International Law instead.
| Paper | Environmental Law questions | Passage topic and source case |
| CLAT PG 2026 | 5 | Environmental impact assessment - Vanashakti v. Union of India (2025); 3 judgment-based, 2 concept-based |
| CLAT PG 2025 | 10 | Climate change - M.K. Ranjitsinh v. Union of India (2024); environmental rule of law - Pragnesh Shah v. Arun Kumar Sharma (2022) |
| CLAT PG 2024 | 5 | Topic not itemised in published analyses |
| CLAT PG 2023 | None reported | - |
| CLAT PG 2022 | 10 | - |
| CLAT PG 2021 | 6 | - |
| CLAT PG 2020 | None reported | - |
Environmental ideas reach other subjects too. The 2025 paper's strict liability passage on M.C. Mehta (1987) was counted under Torts, and the 2026 paper's UNFCCC passage under Public International Law. Counting those, environmental content has appeared in every paper since 2024. Each year's passages are listed in the
CLAT PG previous year papers analysis.
How does CLAT PG test Environmental Law?
CLAT PG tests Environmental Law through extracts from recent Supreme Court judgments, each followed by MCQs on the principle applied, the statute involved and the judgment's place in the case law.
- The 2026 Vanashakti passage had 3 judgment-based questions out of 5, so knowing what the judgment held, and what came after it, mattered.
- Both 2025 passages came from judgments delivered in 2022 and 2024, within 3 years of the exam.
- Every identified passage since 2025 turned on a principle covered below: precaution, sustainable development, climate rights or environmental rule of law.
Recent judgments matter more here than in most subjects, so this page ends with a table of 2025–26 rulings.
What are the high-yield Environmental Law topics for CLAT PG?
CLAT PG Environmental Law questions come from 9 areas:
- Constitutional framework (Articles 21, 48A, 51A(g), 253)
- Environmental principles (sustainable development, precaution, polluter pays, public trust)
- Environment (Protection) Act, 1986 and environmental impact assessment
- Water Act, 1974 and Air Act, 1981
- Forests and the Van (Sanrakshan Evam Samvardhan) Adhiniyam, 1980
- Wildlife, biodiversity and forest rights
- National Green Tribunal and hazardous substances
- Climate change in Indian law
- International environmental law (conventions and ICJ cases)
Constitutional Framework
Which constitutional provisions protect the environment?
Article 21 protects the right to a clean environment, Article 48A directs the State to protect it, Article 51A(g) makes it every citizen's duty, and Article 253 lets Parliament legislate to implement environmental treaties.
| Provision | What it does | Key case or origin |
| Article 21 | Right to life includes a pollution-free environment | Subhash Kumar v. State of Bihar (1991) |
| Article 21, read with 14 | Right against the adverse effects of climate change | M.K. Ranjitsinh v. Union of India (2024, 3 judges) |
| Article 48A | Directive Principle: State to protect and improve the environment, forests and wildlife | Added by the 42nd Amendment (1976) |
| Article 51A(g) | Fundamental Duty: protect the natural environment and have compassion for living creatures | Added by the 42nd Amendment (1976) |
| Articles 32 and 226 | Public interest litigation as the main route for environmental cases | Rural Litigation and Entitlement Kendra v. State of UP (1985, Dehradun quarrying) |
| Article 253 | Parliament can legislate on any subject to implement a treaty | Basis of the Air Act, 1981 and the Environment (Protection) Act, 1986 after the Stockholm Conference |
| Seventh Schedule | Forests and wildlife moved from the State List to the Concurrent List | 42nd Amendment (1976), Entries 17A and 17B |
Which M.C. Mehta cases should you know?
Advocate M.C. Mehta filed a series of public interest cases that built much of Indian environmental law:
| Case | Year | Holding |
| M.C. Mehta v. Union of India (oleum gas leak) | 1987 | Absolute liability for hazardous industries, with no exceptions |
| M.C. Mehta v. Union of India (Ganga tanneries) | 1988 | Tanneries polluting the Ganga ordered to install treatment plants or close |
| M.C. Mehta v. Kamal Nath | 1997 | Public trust doctrine adopted; the State holds natural resources in trust for the public |
| M.C. Mehta v. Union of India (Taj Trapezium) | 1997 | Polluting industries near the Taj Mahal ordered to shift to cleaner fuel or relocate |
| M.C. Mehta v. Union of India (vehicular pollution) | 1998 | Delhi's public transport ordered to switch to CNG |
Environmental Law Principles
What principles do Indian courts apply in environmental cases?
Indian courts apply 8 principles: sustainable development, precaution, polluter pays, public trust, intergenerational equity, absolute liability, environmental rule of law and ecocentrism.
| Principle | Meaning in one line | Leading Indian case |
| Sustainable development | Development that meets present needs without compromising future generations' needs | Vellore Citizens' Welfare Forum v. Union of India (1996, 3 judges) |
| Precautionary principle | Where serious harm is threatened, lack of scientific certainty is no reason to delay preventive action | Vellore Citizens' Welfare Forum (1996); A.P. Pollution Control Board v. M.V. Nayudu (1999) |
| Polluter pays | The polluter bears the cost of the damage and of restoring the environment | Indian Council for Enviro-Legal Action v. Union of India (1996, Bichhri) |
| Public trust doctrine | The State is a trustee of natural resources such as rivers, forests and seashores | M.C. Mehta v. Kamal Nath (1997) |
| Intergenerational equity | The present generation holds the environment in trust for future ones | State of Himachal Pradesh v. Ganesh Wood Products (1995) |
| Absolute liability | A hazardous enterprise is liable for harm with no exceptions | M.C. Mehta v. Union of India (1987, 5 judges) |
| Environmental rule of law | Environmental laws must be implemented through accountable institutions, not just enacted | Hanuman Laxman Aroskar v. Union of India (2019); Pragnesh Shah v. Arun Kumar Sharma (2022) |
| Ecocentrism | Nature and species have value of their own, not only for human use | Centre for Environmental Law, WWF-I v. Union of India (2013) |
[Image: environmental-principles-map.webp — alt: Eight environmental law principles applied by Indian courts with their leading cases]
Who bears the burden of proof under the precautionary principle?
The developer or industry must prove that its activity is environmentally benign; the burden does not lie on the person objecting. Vellore Citizens' Welfare Forum (1996) placed this onus on the actor, and A.P. Pollution Control Board v. M.V. Nayudu (1999) developed it, drawing on scientific uncertainty in environmental cases.
How does absolute liability differ from strict liability?
Absolute liability, laid down in M.C. Mehta v. Union of India (1987), allows none of the exceptions that limit strict liability under Rylands v. Fletcher, and compensation scales with the enterprise's size and capacity. The 2025 paper tested this in a passage counted under Torts; the full comparison table is in the
Law of Torts quick revision notes.
Environment (Protection) Act, 1986 and Environmental Impact Assessment
What does the Environment (Protection) Act, 1986 do?
The Environment (Protection) Act, 1986 is an umbrella law, passed after the Bhopal gas leak under Article 253, that gives the Central Government wide power to protect and improve the environment.
- Section 3: Central Government can take any measure to protect the environment, including setting standards and restricting industries by area. The EIA Notification, 2006 rests on this section.
- Section 5: power to issue directions, including closure of an industry or stopping its water or electricity supply.
- Section 6: power to make rules on pollutant standards and hazardous substances.
- Section 19: a court takes cognisance on a complaint by the Central Government, or by any person after giving 60 days' notice.
- Penalties: the Jan Vishwas (Amendment of Provisions) Act, 2023 replaced imprisonment for most contraventions with monetary penalties. Writer: confirm the current Section 15 amounts before publishing.
How does the EIA process work under the 2006 Notification?
Projects listed in the EIA Notification, 2006 need prior environmental clearance after 4 stages: screening, scoping, public consultation and appraisal.
- Screening: decides whether a Category B project needs a full EIA (B1) or not (B2).
- Scoping: the expert committee sets the terms of reference for the EIA report.
- Public consultation: a public hearing for local people plus written responses from others.
- Appraisal: the expert committee examines the final report and recommends grant or rejection.
Category A projects are appraised at the Centre (MoEFCC and its Expert Appraisal Committee); Category B projects by the State-level authority (SEIAA).
Can environmental clearance be granted after a project has started?
It depends: prior clearance is mandatory, but the Supreme Court has allowed a bounded, one-time regularisation window under Section 3 of the Environment (Protection) Act. The question has produced 6 rulings, and the 2026 paper tested the 2025 one.
| Case | Date | Bench | Holding |
| Common Cause v. Union of India | 2017 | 3 judges | Ex post facto clearance is alien to environmental jurisprudence (mining in Odisha) |
| Alembic Pharmaceuticals v. Rohit Prajapati | 2020 | 3 judges | Ex post facto clearance impermissible; industries already running penalised instead of closed |
| Pahwa Plastics v. Dastak NGO | 2022 | 2 judges | Clearance after operations began allowed in exceptional cases |
| Vanashakti v. Union of India | 16 May 2025 | 2 judges | 2017 notification and 2021 Office Memorandum permitting ex post facto clearance struck down (asked in 2026) |
| CREDAI v. Vanashakti | 18 November 2025 | 3 judges, 2:1 | May 2025 judgment recalled for ignoring earlier precedent; Justice Bhuyan dissented |
| Vanashakti v. Union of India | 29 July 2026 | 3 judges | Prior clearance mandatory; 2017 notification upheld as a bounded amnesty under Section 3; 2021 Office Memorandum quashed with prospective effect; clearances already granted left undisturbed |
[Image: vanashakti-case-timeline.webp — alt: Timeline of Supreme Court rulings on ex post facto environmental clearance from 2017 to 2026]
Water Act, 1974 and Air Act, 1981
How do the Water Act and the Air Act compare?
| Point | Water (Prevention and Control of Pollution) Act, 1974 | Air (Prevention and Control of Pollution) Act, 1981 |
| Enacted under | Article 252 (on State resolutions) | Article 253 (after the 1972 Stockholm Conference) |
| Regulators | Central and State Pollution Control Boards created | Same Boards act under this Act |
| Consent | Consent to establish and operate (Section 25) | Consent to operate in air pollution control areas (Section 21) |
| Special tool | — | Air pollution control areas declared by the State (Section 19) |
| Recent change | Water Amendment Act, 2024 replaced imprisonment for many offences with penalties | Jan Vishwas Act, 2023 decriminalised many offences |
Noise is regulated by the Noise Pollution (Regulation and Control) Rules, 2000 under the Environment (Protection) Act; In re: Noise Pollution (2005) linked freedom from noise to Article 21.
Forests, Wildlife, Biodiversity and Forest Rights
What counts as "forest" under Indian law?
Under T.N. Godavarman Thirumulpad v. Union of India (1996), "forest" carries its dictionary meaning and covers any forest, whatever its ownership or classification, so the forest conservation law applies to all of them.
- Forest (Conservation) Act, 1980, Section 2: prior Central approval is needed to dereserve a forest or use forest land for non-forest purposes.
- 2023 Amendment: renamed the law the Van (Sanrakshan Evam Samvardhan) Adhiniyam, 1980, limited it largely to land recorded as forest, and exempted some categories, such as strategic projects near borders.
- Ashok Kumar Sharma v. Union of India (2024, interim order): States must keep applying the Godavarman dictionary meaning while the challenge to the 2023 Amendment is pending.
- Naveen Solanki v. Rail Land Development Authority (2026): considered whether land for a railway project became "deemed forest" merely because trees grew on it.
- Samatha v. State of Andhra Pradesh (1997): mining leases to non-tribals in Fifth Schedule areas are void.
How does the Wild Life (Protection) Act, 1972 protect species?
The Wild Life (Protection) Act, 1972 bans hunting of listed species, regulates trade in them and creates protected areas.
- Schedules: the 2022 Amendment cut the schedules to 4: Schedules I and II for animals by level of protection, Schedule III for plants, Schedule IV for specimens listed under CITES.
- Protected areas: sanctuaries, national parks, conservation reserves, community reserves and tiger reserves (tiger reserves and the NTCA came through the 2006 Amendment).
- Centre for Environmental Law, WWF-I v. Union of India (2013): Asiatic lions to be relocated to Kuno; the Court adopted an ecocentric, species-best-interest approach.
- M.K. Ranjitsinh v. Union of India (2024): balanced protection of the Great Indian Bustard against solar power lines and recognised the right against climate change harms (asked in 2025).
What does the Biological Diversity Act, 2002 set up?
The Biological Diversity Act, 2002 implements the Convention on Biological Diversity through a 3-tier structure and access-and-benefit-sharing rules for biological resources.
| Tier | Body | Role |
| National | National Biodiversity Authority (Chennai) | Approves access by foreign entities and benefit sharing |
| State | State Biodiversity Boards | Regulate access by Indian entities |
| Local | Biodiversity Management Committees | Maintain People's Biodiversity Registers |
The Biological Diversity (Amendment) Act, 2023 decriminalised offences and eased rules for the AYUSH sector.
What rights does the Forest Rights Act, 2006 recognise?
The Forest Rights Act, 2006 recognises individual and community rights of Scheduled Tribes and other traditional forest dwellers over forest land and resources, with the gram sabha deciding claims. In Orissa Mining Corporation v. Ministry of Environment and Forests (2013, Niyamgiri), the Supreme Court left it to the gram sabhas to decide whether bauxite mining affected their religious and cultural rights.
National Green Tribunal and Hazardous Substances
What can the National Green Tribunal decide?
The National Green Tribunal decides civil cases raising a substantial question relating to the environment under the 7 laws in Schedule I of the National Green Tribunal Act, 2010.
- Schedule I laws: Water Act, Water Cess Act, Forest Conservation Act, Air Act, Environment (Protection) Act, Public Liability Insurance Act and Biological Diversity Act. The Wild Life (Protection) Act and the Forest Rights Act are outside it.
- Section 14: original jurisdiction; applications within 6 months of the cause of action.
- Section 15: relief, compensation and restitution of property and environment.
- Section 20: the Tribunal must apply sustainable development, the precautionary principle and polluter pays.
- Section 22: appeal to the Supreme Court within 90 days.
- Municipal Corporation of Greater Mumbai v. Ankita Sinha (2021, 3 judges): the Tribunal can take suo motu cognisance.
- Narender Bhardwaj v. 108 Super Complex RWA (2026): the Tribunal's jurisdiction is strictly limited to the Schedule I laws.
What came out of the Bhopal gas leak?
| Development | Year | Point |
| Bhopal Gas Leak Disaster (Processing of Claims) Act | 1985 | Union of India made the sole representative of victims |
| Union Carbide Corporation v. Union of India | 1989 | Settlement of USD 470 million approved |
| Charan Lal Sahu v. Union of India | 1990 | Claims Act upheld on the parens patriae principle |
| Public Liability Insurance Act | 1991 | Hazardous-substance handlers must insure and pay immediate no-fault relief |
| Union of India v. Union Carbide (curative petition) | 2023 | 5 judges refused to reopen the settlement for more compensation |
Climate Change in Indian Law
Is there a right against climate change in India?
Yes. In M.K. Ranjitsinh v. Union of India (21 March 2024), a 3-judge bench recognised a right against the adverse effects of climate change under Articles 14 and 21.
The case began as a challenge to overhead power lines that killed the Great Indian Bustard. The Court modified its earlier blanket order on undergrounding lines, holding that India's solar-energy commitments also protect the environment. CLAT PG 2025 set a passage on it.
What are India's climate commitments?
- Updated NDC (2022): cut the emissions intensity of GDP by 45% from 2005 levels by 2030, and reach about 50% of installed power capacity from non-fossil sources by 2030.
- Net zero: by 2070, announced at COP26 (Glasgow, 2021).
- Energy Conservation (Amendment) Act, 2022: empowers the Centre to set up a carbon credit trading scheme.
International Environmental Law
Which environmental conventions should you know?
| Year | Instrument | Key point |
| 1971 | Ramsar Convention | Conservation of wetlands of international importance |
| 1972 | Stockholm Declaration | First UN conference on the human environment; created UNEP |
| 1973 | CITES | Regulates international trade in endangered species |
| 1985, 1987 | Vienna Convention, Montreal Protocol | Ozone layer; the 2016 Kigali Amendment phases down HFCs |
| 1989 | Basel Convention | Transboundary movement of hazardous waste |
| 1992 | Rio Declaration, UNFCCC, CBD | Earth Summit; principles of precaution and polluter pays; climate and biodiversity treaties |
| 1997 | Kyoto Protocol | Binding emission targets for developed (Annex I) countries |
| 2000, 2010 | Cartagena Protocol, Nagoya Protocol | Biosafety of living modified organisms; access and benefit sharing under the CBD |
| 2001 | Stockholm Convention | Persistent organic pollutants |
| 2013 | Minamata Convention | Mercury |
| 2015 | Paris Agreement | Nationally Determined Contributions; hold warming well below 2°C, pursue 1.5°C |
| 2022 | Kunming-Montreal Global Biodiversity Framework | Protect 30% of land and sea by 2030 |
| 2023 | BBNJ Agreement | Marine biodiversity in areas beyond national jurisdiction (the High Seas Treaty) |
[Image: environmental-conventions-timeline.webp — alt: Timeline of international environmental conventions from Ramsar 1971 to the BBNJ Agreement 2023]
Which Rio principles are tested most?
The 1992 Rio Declaration has 27 principles; these 4 carry over directly into Indian case law:
- Principle 7: common but differentiated responsibilities.
- Principle 15: the precautionary approach.
- Principle 16: the polluter should bear the cost of pollution.
- Principle 17: environmental impact assessment for activities likely to cause significant harm.
Which international cases shaped environmental law?
| Case | Year | Holding |
| Trail Smelter (USA v. Canada) | 1938, 1941 | No State may use its territory to cause serious harm to another's |
| Gabčíkovo-Nagymaros (Hungary v. Slovakia) | 1997 | ICJ recognised sustainable development as a concept balancing growth and protection |
| Pulp Mills (Argentina v. Uruguay) | 2010 | ICJ held environmental impact assessment a requirement of general international law |
| ITLOS Advisory Opinion on climate change | May 2024 | Greenhouse gas emissions count as marine pollution under UNCLOS |
| ICJ Advisory Opinion, Obligations of States in respect of Climate Change | 23 July 2025 | Unanimous: States must prevent significant climate harm with due diligence and cooperate in good faith; a breach can be an internationally wrongful act |
How should you revise Environmental Law in the last 30 days before CLAT PG?
Revise Environmental Law in the final 30 days by fixing the 8 principles to their cases, following the latest judgments, and solving the 2024–2026 passages under timed conditions.
- Learn the principles table until you can name the leading case for each principle without looking.
- Read the Vanashakti sequence from 2017 to 2026 in order; the paper tests what changed and why.
- Read the 3 identified passage judgments in the original: Pragnesh Shah (2022), Ranjitsinh (2024) and Vanashakti (2025).
- Recall the convention table by year once a week, pairing each convention with one Indian law that implements it.
- Take full-length mocks in the final 2 weeks with the 0.25-mark penalty applied.
Which 2025–26 rulings belong in your Environmental Law notes?
| Ruling | Date | Point to note |
| Vanashakti v. Union of India | 16 May 2025 | Ex post facto clearance regime struck down (asked in 2026) |
| ICJ Advisory Opinion on climate change | 23 July 2025 | States owe due-diligence obligations to prevent significant climate harm |
| CREDAI v. Vanashakti | 18 November 2025 | May 2025 judgment recalled, 2:1 |
| Narender Bhardwaj v. 108 Super Complex RWA | 2026 | NGT jurisdiction limited to Schedule I laws |
| Naveen Solanki v. Rail Land Development Authority | 2026 | "Deemed forest" question for land with trees on a railway project |
| Vanashakti v. Union of India | 29 July 2026 | Prior clearance mandatory; bounded amnesty under Section 3 valid; 2021 Office Memorandum quashed prospectively |
Self-Test: 10 Environmental Law Questions
- Which case adopted the public trust doctrine in India? (a) Vellore Citizens' Welfare Forum (b) M.C. Mehta v. Kamal Nath (c) Ganesh Wood Products (d) Subhash Kumar
- Which Article was added by the 42nd Amendment to direct the State to protect the environment? (a) 47 (b) 48 (c) 48A (d) 51A(k)
- Under the precautionary principle as applied in India, the burden of proof lies on: (a) the objector (b) the State (c) the developer (d) the Pollution Control Board
- Which law is outside Schedule I of the NGT Act, 2010? (a) Air Act (b) Biological Diversity Act (c) Wild Life (Protection) Act (d) Public Liability Insurance Act
- Which case gave "forest" its dictionary meaning? (a) Samatha (b) T.N. Godavarman (c) Niyamgiri (d) Kamal Nath
- M.K. Ranjitsinh (2024) recognised a right against climate change harms under: (a) Article 21 only (b) Articles 14 and 21 (c) Article 48A (d) Article 51A(g)
- Which ICJ case held environmental impact assessment a requirement of general international law? (a) Trail Smelter (b) Corfu Channel (c) Pulp Mills (d) Gabčíkovo-Nagymaros
- On 29 July 2026, the Supreme Court held the 2021 Office Memorandum on ex post facto clearance: (a) valid (b) quashed prospectively (c) quashed retrospectively (d) referred to a larger bench
- Under the Paris Agreement, countries submit: (a) Annex I targets (b) Nationally Determined Contributions (c) Biodiversity Registers (d) Consent to operate
- Which Act set up a 3-tier structure of national, State and local bodies? (a) Environment (Protection) Act (b) Forest Rights Act (c) Biological Diversity Act (d) Air Act
Answers: 1 (b), 2 (c), 3 (c), 4 (c), 5 (b), 6 (b), 7 (c), 8 (b), 9 (b), 10 (c).
What mistakes cost marks in Environmental Law?
- Stopping at the May 2025 Vanashakti ruling: it was recalled in November 2025 and replaced by the July 2026 judgment.
- Mixing up principles: precaution prevents uncertain harm; polluter pays allocates cost after harm.
- Assuming the NGT hears every environmental law: wildlife and forest rights cases are outside its Schedule I.
- Ignoring international law: climate-treaty passages appear under Public International Law too.
FAQs
Is Environmental Law important for CLAT PG?
Yes. It has carried 5–10 questions in every paper since 2024, and environmental passages appear under Torts and International Law as well.
How many Environmental Law questions come in CLAT PG?
It varies. Recent papers had 5 (2024), 10 (2025) and 5 (2026) questions classified as Environmental Law.
Which Environmental Law topic is most important for CLAT PG?
Recent Supreme Court judgments applying environmental principles, especially on environmental clearance and climate change. Both topics appeared in the last two papers.
Are international conventions asked in CLAT PG?
Yes. The 2026 paper had a UNFCCC passage, counted under Public International Law. More strategy pieces sit under
CLAT PG preparation.
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