The ICJ and the Environment: Key Cases
No environmental treaty confers general jurisdiction on the International Court of Justice, yet judgments and opinions delivered between 1949 and 2018 have made it the principal judicial architect of general international environmental law.
This article follows that authority: Corfu Channel and Nuclear Weapons, Gabčíkovo-Nagymaros (1997), Pulp Mills (2010) and environmental compensation (2018).
Corfu Foundations
Territorial Duty
The duty not to permit territory to be used to the detriment of other States originates in Corfu Channel (1949), a case on mines in Albanian waters.
"… every State's obligation not to allow knowingly its territory to be used for acts contrary to the rights of other States."
Stockholm Principle 21
Stockholm Principle 21 (1972) restated it for the environment. Rio Principle 2 (1992) adds developmental policies: States have the sovereign right to exploit their own resources under their own environmental and developmental policies, together with the responsibility to ensure that activities within their jurisdiction or control do not damage the environment of other States or of areas beyond national jurisdiction.
Nuclear Weapons Opinion
Living Space
In paragraph 29 of the Nuclear Weapons advisory opinion (1996), the Court stated the general environmental obligation as customary law.
"The existence of the general obligation of States to ensure that activities within their jurisdiction and control respect the environment of other States or of areas beyond national control is now part of the corpus of international law …"
Armed Conflict
The Court added, in paragraph 30, that environmental treaties are not wholly displaced by armed conflict. States must take environmental considerations into account when assessing what is necessary and proportionate in pursuing legitimate military objectives, and respect for the environment is one of the elements for judging whether an action conforms to the principles of necessity and proportionality.
Gabčíkovo Facts
The 1977 Treaty
In 1977 Hungary and Czechoslovakia concluded a treaty for a system of dams and locks on the Danube at Gabčíkovo and Nagymaros, for hydroelectric power, flood control and navigation.
Hungary's Suspension
In 1989 Hungary suspended and then abandoned its part of the works, citing ecological concerns, and in May 1992 purported to terminate the treaty. Czechoslovakia (and later Slovakia) proceeded with a unilateral "Variant C", diverting the Danube into a bypass canal on its own territory.
The Compromis
Submitted by special agreement in 1993, the dispute was decided on 25 September 1997. The questions were necessity, termination, the lawfulness of Variant C, and the future conduct of the parties.
Necessity Plea
Article 25
Hungary's principal defence was ecological necessity, examined against the rule now codified in Article 25 of the ILC Articles on State Responsibility (2001). Article 25(1) allows necessity to preclude wrongfulness only if the act is the only way for the State to safeguard an essential interest against a grave and imminent peril, and does not seriously impair an essential interest of the State or States towards which the obligation exists, or of the international community as a whole.
Essential Interest
The Court accepted that an environmental concern may be an essential interest of a State. In paragraph 53 of the judgment it acknowledged without difficulty that Hungary's concerns for its natural environment in the region affected by the Project related to an "essential interest" of that State, within the meaning of Article 33 of the ILC's draft.
Imminent Peril
It also read imminence purposively, so that a long-term ecological peril may qualify. In paragraph 54 the Court held that a peril appearing in the long term may be "imminent" as soon as it is established that its realization, however far off, is no less certain and inevitable.
Peril Not Proven
The plea nonetheless failed on the facts: scientific uncertainty alone could not establish an objectively existing, grave and imminent peril, and Hungary had other means of response. Necessity excuses non-performance; it does not terminate a treaty.
Treaty Law
Pacta Sunt Servanda
The case is a leading authority on the law of treaties. The notes of De Facto IAS record it as an application of the rule of treaty observance.
This was epitomized by the ICJ's advisory opinion on the Genocide Convention (1951), stressing that states cannot unilaterally impair the treaty's core objectives. The principle was vividly seen in action in the Case Concerning the Gabčíkovo-Nagymaros Project (Hungary v. Slovakia) where the ICJ held that both nations failed to uphold the pacta sunt servanda principle.
Article 26 of the Vienna Convention on the Law of Treaties (1969) provides that every treaty in force binds its parties and must be performed by them in good faith.
Material Breach
The Court confirmed that Article 60 of the Vienna Convention on material breach reflects customary law, but held that Hungary's termination of May 1992 was premature, and that Hungary's own prior breach disentitled it from invoking the other party's breach.
Changed Circumstances
Hungary also invoked fundamental change of circumstances, summarised in the De Facto IAS notes as follows.
Art. 62(1): A party can invoke the doctrine if: (i) The change pertains to circumstances present at the treaty's signing. (ii) The alteration is fundamental. (iii) The parties hadn't anticipated the change during the treaty's conclusion. (iv) Those circumstances were crucial for the parties' consent.
Article 62(1) of the Vienna Convention bars a party from invoking an unforeseen fundamental change of circumstances as a ground for terminating or withdrawing from a treaty unless those circumstances formed an essential basis of consent and the change radically transforms the extent of obligations still to be performed. In paragraph 104 the Court stressed that stability of treaty relations requires that the plea be applied only in exceptional cases.
Treaty Survives
The Court concluded that the 1977 Treaty remained in force, since its own provisions (Articles 15, 19 and 20) could accommodate new environmental norms.
Countermeasures
Variant C
Slovakia justified Variant C as a countermeasure against Hungary's wrongful suspension. In paragraph 83 the Court stated the conditions of lawful countermeasures: among them, that a countermeasure must be taken in response to a previous international wrongful act of another State and be directed against that State.
Proportionality Fails
Variant C failed the test of proportionality, since Czechoslovakia had assumed unilateral control of a shared resource and deprived Hungary of its equitable share of the Danube's waters. Article 51 of the ILC Articles requires countermeasures to be commensurate with the injury suffered, taking into account the gravity of the wrongful act and the rights in question.
New Norms
Continuing Activities
The most cited passage of the judgment, paragraph 140, recognises that environmental norms developed after 1977 apply to a treaty in force. The Court observed that mankind has long interfered with nature for economic and other reasons, often without regard to the environment, but that new scientific insights and a growing awareness of risks to present and future generations have produced new norms and standards in a great number of instruments over the last two decades. It then drew the consequence for existing activities.
"Such new norms have to be taken into consideration, and such new standards given proper weight, not only when States contemplate new activities but also when continuing with activities begun in the past."
Sustainable Development
In the same paragraph 140 the Court adopted sustainable development as the reconciling concept, without describing it as a rule of custom.
"This need to reconcile economic development with protection of the environment is aptly expressed in the concept of sustainable development."
Duty to Negotiate
The Court directed the parties to negotiate in good faith to give effect to the Treaty's objectives, favouring a continuing cooperative regime over a decisive allocation of rights.
Pulp Mills Facts
The 1975 Statute
The Statute of the River Uruguay (1975) created the River Uruguay Commission (CARU) and prescribed, in Articles 7 to 12, procedures for notifying works liable to affect the river.
Orion Mill
Uruguay authorised pulp mills at Fray Bentos, including the Orion (Botnia) mill. Argentina alleged breach of the procedural duties and risk of pollution, and the Court delivered judgment on 20 April 2010.
Issues
Prevention Duty
Customary Rule
The Court's statement of prevention is the leading modern formulation of the Corfu duty. In paragraph 101 it held that the principle of prevention, as a customary rule, has its origins in the due diligence required of a State in its territory, and it traced the principle to the Corfu Channel obligation not to allow knowingly its territory to be used for acts contrary to the rights of other States. It then stated the content of the duty.
"A State is thus obliged to use all the means at its disposal in order to avoid activities which take place in its territory, or in any area under its jurisdiction, causing significant damage to the environment of another State."
Draft Articles
The ILC's Articles on Prevention of Transboundary Harm (2001) express the same standard. Article 3 requires the State of origin to take all appropriate measures to prevent significant transboundary harm or at any event to minimize the risk thereof.
Procedural Link
The Court treated the procedural duties as the means of discharging prevention. In paragraph 102 it said that the obligation to inform CARU allows the initiation of the co-operation between the Parties which is necessary to fulfil the obligation of prevention.
Due Diligence
The obligation is one of conduct, not result: liability follows from want of vigilance, not from harm as such. In paragraph 197 the Court described it as an obligation to act with due diligence in respect of all activities under the jurisdiction and control of each party. This entails not only the adoption of appropriate rules and measures but also a certain level of vigilance in enforcing them and exercising administrative control over public and private operators, including monitoring of their activities. Article 7 of the ILC Articles on Prevention (2001) similarly requires any decision authorising an activity within their scope to rest on an assessment of the possible transboundary harm, including any environmental impact assessment.
Impact Assessment
General Requirement
Pulp Mills is the leading authority that an environmental impact assessment is required by general international law. Paragraph 204 refers to a practice that has gained so much acceptance among States that it may now be considered:
"… a requirement under general international law to undertake an environmental impact assessment where there is a risk that the proposed industrial activity may have a significant adverse impact in a transboundary context, in particular, on a shared resource."
The Court added that due diligence, and the duty of vigilance and prevention it implies, would not be considered exercised if a party planning works liable to affect the régime of the river or the quality of its waters did not undertake an environmental impact assessment of their potential effects.
Content Left Open
The Court left the content of an assessment to domestic law and treated the UNEP Goals and Principles as guidelines. In paragraph 205 it observed that neither the 1975 Statute nor general international law specifies the scope and content of an assessment, and that Argentina and Uruguay are not parties to the Espoo Convention. The UNEP Goals and Principles, it noted, are not binding on the Parties but, as guidelines issued by an international technical body, must be taken into account by each Party under Article 41(a) in adopting measures within its domestic regulatory framework.
Treaty Parallels
Comparable duties appear in the law of the sea. Under UNCLOS (1982), Article 192 obliges States to protect and preserve the marine environment, and Article 194(2) requires them to ensure that activities under their jurisdiction or control do not cause pollution damage to other States and their environment. Article 206 requires States with reasonable grounds to believe that planned activities may cause substantial pollution or significant and harmful changes to the marine environment to assess the potential effects, as far as practicable, and to communicate the results.
Rio Principle 17
Principle 17 of the Rio Declaration (1992) provides that environmental impact assessment, as a national instrument, shall be undertaken for proposed activities likely to have a significant adverse impact on the environment and subject to a decision of a competent national authority.
Precaution
Burden of Proof
Argentina contended that precaution reverses the burden of proof. The Court rejected the contention in paragraph 164.
"… while a precautionary approach may be relevant in the interpretation and application of the provisions of the Statute, it does not follow that it operates as a reversal of the burden of proof."
The Court added that nothing in the 1975 Statute itself indicates that it places the burden of proof equally on both Parties.
Rio Principle 15
This accords with Rio Principle 15, a standard of caution in choosing measures rather than a rule of evidence. It calls for wide application of the precautionary approach according to States' capabilities, and says that where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.
Sustainable Development
Balancing Principle
In Pulp Mills the Court returned to Gabčíkovo, reading Article 27 of the Statute in the light of sustainable development. In paragraph 177 it held that Article 27 embodies the interconnectedness between equitable and reasonable utilization of a shared resource and the balance between economic development and environmental protection that is the essence of sustainable development.
Shared Resources
The same balance appears in the 1997 UN Watercourses Convention. Article 7(1) requires watercourse States, in utilizing an international watercourse in their territories, to take all appropriate measures to prevent the causing of significant harm to other watercourse States.
Procedure and Remedy
Procedural Breach
The Court held the procedural duties to be autonomous, and found that Uruguay breached them by authorising the mills before the Statute's process was complete. In paragraph 282(1) it found that Uruguay had breached its procedural obligations under Articles 7 to 12 of the 1975 Statute and that the declaration of this breach constitutes appropriate satisfaction.
Notification Principle
The procedural duties of the Statute accord with the general duty of prior notification stated in Principle 19 of the Rio Declaration. It requires States to give prior and timely notification and relevant information to potentially affected States on activities that may have a significant adverse transboundary environmental effect, and to consult with them at an early stage and in good faith.
Substantive Compliance
In paragraph 282(2) the Court found that Uruguay had not breached its substantive obligations under Articles 35, 36 and 41 of the 1975 Statute.
Criticism
The judgment is criticised because a procedural breach produced only a declaration, no dismantling of the mill was ordered, and the Court's handling of scientific evidence was thought insufficiently rigorous.
Compensation
Certain Activities
Certain Activities Carried Out by Nicaragua in the Border Area arose from dredging of the San Juan River and a canal across Costa Rican territory. The merits judgment (2015) applied the Pulp Mills approach to impact assessment, and compensation was fixed in 2018.
Environmental Damage
The 2018 judgment is the first award of compensation for environmental damage as such. In paragraph 42 the Court held:
"… damage to the environment, and the consequent impairment or loss of the ability of the environment to provide goods and services, is compensable under international law."
Such compensation may include indemnification for the impairment or loss of environmental goods and services in the period prior to recovery, and payment for the restoration of the damaged environment.
India's Practice
Customary Incorporation
Indian courts have drawn extensively on these principles. In Vellore Citizens' Welfare Forum v. Union of India (1996) the Supreme Court held that the precautionary principle and the polluter-pays principle are part of the environmental law of the country, reasoning that they form part of customary international law and are therefore enforceable in the absence of contrary legislation.
Statutory Mandate
The National Green Tribunal Act 2010 directs the Tribunal, in section 20, to apply the principles of sustainable development, the precautionary principle and the polluter-pays principle in its decisions. Article 51(c) of the Constitution directs the State to foster respect for international law, and Articles 21 and 48A supply the municipal basis of environmental protection.
Assessment
Strengths
The Court has established, incrementally, the duty of prevention, the duty to assess, the relevance of sustainable development and the compensability of environmental damage. Its limits are equally apparent: it prefers procedural to substantive standards, defers on scientific evidence, and has not treated precaution as custom.
Answer Map
In an answer, link each doctrine to its case: Corfu Channel (territorial duty), Nuclear Weapons (general obligation), Gabčíkovo (necessity, new norms, sustainable development), Pulp Mills (prevention, EIA, precaution) and Certain Activities (compensation).
FAQs
What is the main contribution of Gabčíkovo-Nagymaros to environmental law? The ICJ recognised the environment as a matter of essential State interest, endorsed the concept of sustainable development, and held that new environmental norms must be taken into consideration even when continuing activities begun in the past. It nevertheless rejected Hungary's plea of ecological necessity.
What did the ICJ decide in the Pulp Mills case? In its judgment of 20 April 2010 the Court held that Uruguay had breached its procedural obligations to inform and notify the River Uruguay Commission and Argentina, but had not breached its substantive obligations to prevent pollution. The declaration of breach was held to be appropriate satisfaction.
Is an environmental impact assessment required by general international law? Yes. In Pulp Mills the Court held that it may now be considered a requirement under general international law to undertake an environmental impact assessment where a proposed industrial activity risks significant adverse transboundary impact, particularly on a shared resource.
Does the precautionary principle reverse the burden of proof? No. The Court held in Pulp Mills that a precautionary approach may be relevant to the interpretation of a treaty, but it does not operate as a reversal of the burden of proof.
Is environmental damage compensable under international law? Yes. In Certain Activities Carried Out by Nicaragua (Compensation, 2018) the Court held for the first time that damage to the environment, and the consequent impairment or loss of the ability of the environment to provide goods and services, is compensable under international law.
