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State Responsibility for Transboundary Air Pollution in International Law$

Phoebe Okowa

Print publication date: 2000

Print ISBN-13: 9780198260974

Published to Oxford Scholarship Online: March 2012

DOI: 10.1093/acprof:oso/9780198260974.001.0001

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Determination of Responsibility

Determination of Responsibility

(p.171) 6 Determination of Responsibility
State Responsibility for Transboundary Air Pollution in International Law

Phoebe N. Okowa

Oxford University Press

Abstract and Keywords

This chapter examines the principles of state responsibility and their relevance to air pollution obligations. It also looks at the many problems involved in the application of causal principles, determination of what constitutes damage, and the apportionment of responsibility between contributing states. It argues that, since the regime of state responsibility evolved and developed in a discretely bilateral context, its application to problems of transboundary air pollution, which by their very nature are multilateral in character, remains fraught with difficulties. Given the paucity of international jurisprudence on these issues, a number of possible solutions will be suggested de lege ferenda.

Keywords:   transboundary air pollution, damage, air pollution obligations, state responsibility

6.1. Introduction

The treaty obligations and customary law duties considered in the previous chapters rest on the general assumption that non-compliance may call into question the responsibility of the state in breach on the international plane. This chapter examines the imposition of state responsibility as a technique for supervising compliance with those norms. The exact circumstances giving rise to responsibility in each case depends on the precise formulation of the duty breached, and in particular whether it requires the state to adopt a specified line of conduct or the achievement of a particular result.

It must nevertheless be stated at the outset that breach in and of itself is not a sufficient basis for the imposition of responsibility. The conditions of responsibility and the remedies available may differ with the circumstances of the breach and with the interests affected. Whether or not a state will be held responsible on the international plane will in addition to breach of a distinct obligation be determined by the normative principles of state responsibility; the secondary rules which determine the legal consequences of failure to fulfil the obligations established by the primary rules.1 This chapter considers their application to transboundary air pollution obligations.2

Two broad categories of obligations are considered. There are those which in the terminology of the ILC may be described as obligations of conduct, in so far as they merely prescribe a modus operandi without dictating that any result should be achieved. The procedural duties on exchange of information, notification, and consultation may be described as obligations of conduct in so far as they only require states to observe certain procedural prerequisites without dictating any particular outcome. They are examples of those instances where non-compliance with the requisite standard per se injures the (p.172) interests that the standards protect, and may consequently call into question the responsibility of states in default. The second category may be described as obligations of result. These, whilst leaving a wide margin of appreciation to states as to choice of means, nevertheless dictate that a particular result must be achieved.3

The standards to be attained under the Sulphur and Nitrogen Protocols may be described as obligations of result, in so far as they leave each state free to bring about a particular result by means of its own choice. In the case of the first Sulphur Protocol a reduction in sulphur emissions by at least 30 per cent is required, while in the case of the Nitrogen Protocol nitrogen emissions had to be stabilized by the stated date.4 Similarly, the second Sulphur Protocol5 has set a number of emission targets for the states parties, but in each case they are left free to devise their own methods of bringing the changes about. These distinctions are important because a finding of breach will depend on the nature and form of the obligation.6

In principle, the duty prohibiting significant transboundary harm recognized in the Trail Smelter Case,7 and in Principle 21 of the Stockholm Declaration, and other general instruments giving effect to it, only call into question the responsibility of a state if a significant level of harm results from the pollution.8 The requirement of a threshold level of harm means that not all forms of pollution give rise to responsibility. In the absence of precise standards to be observed, responsibility is dependent on the occurrence of physical harm. This obligation may therefore be categorized as one of result, since it leaves each state free to determine the means for ensuring that activities on its territory do not cause significant transboundary harm. In these instances, international law is not as such concerned with the modalities of complying with the obligation. In addition to the distinction between obligations of conduct and those of result, it is also necessary to discuss other factors that impinge on the nature and extent of a state's responsibility. Thus the duration of the breach, its seriousness, and the existence of material injury all have important bearings on the nature and extent of a state's responsibility.

(p.173) 6.2. The Nature and Forms of Breach

(i) Instantaneous and Continuing Breaches

In the literature, and in the jurisprudence of international tribunals, a distinction is sometimes made between instantaneous and continuing breaches of international obligations.9 The first type involves a breach which occurs at a precise point in time but terminates instantly, even though it may give rise to effects of a continuing character. A discrete accident whose effects are felt immediately exemplifies the first type. The accident at the Chernobyl nuclear plant may be characterized as an instantaneous breach, since the delictual conduct took place at a specific time and place even if the effects remain of a continuing character.

A continuing breach of an international duty, on the other hand, refers to successive acts or state of affairs at variance with that required by the obligation. Here, the responsibility of the state extends to the entire period that its act is not in conformity with that required by the obligation.10 Thus, failure to supply information, or enter into consultation, as well as the continuous emission of a significant level of pollution in principle are all instances where a state's breach of an obligation is of a continuing character, until such time that its conduct is in conformity with that required by law.

The literature and the jurisprudence of international tribunals maintain a distinction between the two modes of breach, and on occasion the consequences attaching to breach may depend on whether it is of an instantaneous or a continuing character. In this context it should be noted that Article 25 of the draft Articles on responsibility prepared by the ILC provide in part that

The breach of an international obligation by an act of the state having a continuing character occurs at the moment when the act begins. Nevertheless, the time of commission of the breach extends over the entire period during which the act continues and remains not in conformity with the international obligation.11

In the Iran Hostages Case,12 the International Court observed that the failure of Iran to release the hostages was a continuing breach of treaty and customary law obligations binding on it. That, as a result, the responsibility of Iran was engaged for the entire duration of the breach.13 The French-New Zealand arbitration tribunal in the Rainbow Warrior Case,14 has underscored the importance of this distinction, and stated that in the case of a continuing breach of an obligation, the state whose conduct is called into question is under a duty to stop the (p.174) breach immediately and resume performance as required by law.15 The category of continuing breach and its importance in the enforcement of obligations has been expressly recognized by both Riphagen and Arangio-Ruiz in their capacities as Rapporteurs of the Commission on the state responsibility topic.16

This category also has a distinct relevance in the context of transboundary air pollution from industrial and automobile sources. By their very nature such violations are of a continuing character. Where the procedural obligations are not complied with, the resulting breach is also continuous in form, until measures are taken to ensure compliance with the stipulated obligations. Failure to notify, supply information, or consult will in principle engage the responsibility of the state for the entire period that it fails to act in accordance with international legal norms.

Moreover, where a state emits pollutants beyond the permissible thresholds of tolerance, the continuous emission of pollutants amounts to successive breaches of the obligations, and the responsibility of the state will continue to run until the emissions are abated.17 A tribunal may also be inclined to view a continuous breach as a deliberate and flagrant violation of an international obligation. Thus, the classification is not purely theoretical but has a practical value, since the seriousness of the breach and its prolongation cannot fail to have considerable bearing on the form of reparation for a violation presenting these features.18 On a particular occasion the admissibility of a claim or the jurisdiction of a tribunal may turn on the continuing character of the violation. It follows that where a law that prohibits a certain level of pollution only comes into effect after the delictual act has commenced, it may still form the legitimate basis of a claim if the breach is of a continuing character.19

These acts must, however, be distinguished from those breaches which begin and cease to exist at the same moment. In relation to instantaneous breaches, the responsibility of the state is conterminous with the occurrence of the breach. The effects of the breach as in the case of Chernobyl nuclear accident may be of a continuing character, but the wrongful act giving rise to responsibility occurred at a definite point in time. Whether the responsibility of the state extends to all the losses incurred will depend on the application of other legal principles, in particular that of proximate causality.

(p.175) (ii) Damage to Persons or Property

It was noted in Chapter 2 that none of the treaties regulating transboundary air pollution contains specific provisions on consequences of breach. As a result what amounts to damage in this context must be determined by reference to general international law.

When the breach of a duty owed to a state results in material loss or damage, it is uncontested that under general international law such loss can form the subject-matter of redress, usually compensation in the form of a financial quantification of the injury. Even where it is accepted that damage is not a necessary condition for responsibility, its presence certainly strengthens the legal interest that a state has in insisting on the observance of the duties owed to it. What counts as material injury will depend on the nature of the duty and the interests it purports to protect. In the literature, and in the practice of states, there is support for the view that physical or direct injury to persons or property resulting in identifiable economic loss amounts to material injury.20

Damage to person or property is the least controversial, and this category of loss is to be found in a long line of state and treaty practice, as well as in the jurisprudence of international tribunals.21. For instance, Article 1 of the Convention on International Liability for Damage Caused by the Space Objects defines damage as any ‘loss of life, personal injury or other impairment of health, or loss or damage of property’.22 In Article 1 of the 1979 ECE Convention, air pollution is defined to include the introduction of substances endangering human life as well as material property.23 While it is arguable that the provision is not directly concerned with what amounts to damage for purposes of state responsibility, it nevertheless indicates the interests that may be affected by transboundary air pollution, and which may therefore form the subject-matter of a claim.

The Nuclear Civil Liability Conventions employ a similar terminology and restrict compensation to property losses or injury to persons.24 It is therefore arguable that in those instances where state victims of transboundary air (p.176) pollution suffer quantifiable damage to persons or property, there is little doubt that compensation can be obtained under treaty instruments as well as under general international law.

(iii) Detrimental Alteration of Environment Quality

Is a state responsible in those instances where the injury suffered although not quantifiable in monetary terms nevertheless amounts to detrimental alteration of the quality of its environment? The so-called harm to the environment has been defined as involving harm to things such as air, water, and space, which cannot be appropriated, which are shared and used by everyone, and do not belong to anyone in particular.25 It goes beyond interferences with human beings and their property and requires a preservation of the natural order, including non-use values. In the case of transboundary air pollution, this may extend to the physical features of the atmosphere. The rationale behind treating harm to the environment as a distinct object of concern proceeds from the premiss that the global environment is an indivisible whole, with the result that a breakdown in any one of the ecological subsystems necessarily destabilizes other parts of the environment, even where the impact may not be immediately visible.26

Although there is some support in the literature and in the practice of states27 for treating such alteration as an item of damage, it is suggested that some caution is called for in the absence of agreement as to what amounts to detrimental alteration, or mechanisms for evaluating it.28 There is general acceptance that states are expected to tolerate a certain measure of pollution, and, with the possible exception of radioactive contamination, it is generally agreed that such pollution only becomes actionable if it is significant or appreciable. On the other hand, it is increasingly realized that given the incremental nature of processes of degradation, any amount of pollution no matter how insignificant prejudicially alters the quality of a state's environment and is a proper subject-matter for regulation. It has therefore been argued that the interest of a state in the quality of its environment, balanced ecosysterns (p.177) wildlife, as well as aesthetic values deserves distinct protection under international law, irrespective of whether it can be objectively characterized as diminution in property value.29 The issue deserves extended consideration, in view of its importance to the topic under consideration.

In the practice of states there is some reliance on the alteration of environmental quality as a distinct item of damage. In Chapter 4 it was noted that the Australian pleadings in the Nuclear Tests Cases had in part invoked the independent right of Australia to determine whether its atmosphere or peoples should be exposed to radiation from artificial sources. There was no specific allegation of damage to persons or property, nor did the Australian Government claim compensation. A substantial part of Australia's argument was devoted to the allegation that radioactive contamination of the environment was inherently harmful, and that this fact was not necessarily dependent on the presence of tangible damage to persons or property.30

It was argued that this was in part due to the latency of radiation injuries and the cumulative character of the processes of degradation.31 In support of its claim, Australia relied on a considerable wealth of scientific opinion that any amount of exposure to radiation no matter how insignificant was harmful to Australia and its people.32

These claims of the Australian Government were contested by France, who in a communication to the Court maintained that there could be no responsibility in the absence of proven damage.33 It was implicit in the French communication that France was of the view that the mere detrimental alteration of environmental quality per se could not give rise to responsibility. Although the full Court did not address itself to these issues, a number of judges in their joint dissent were sympathetic to the Australian argument that the involuntary receipt of pollutants per se could in principle be a legitimate basis for an action in international law.34

In its claim against the Soviet Union for damage caused by the Soviet Cosmos 954, Canada maintained that the deposit of debris in the environment rendering part of Canada's territory unfit for use constituted ‘damage (p.178) to property’ within the meaning of the Convention on International Liability for Damage Caused by Space Objects and under customary law.35 On the face of it, it would appear that Canada was alleging that the mere alteration of the natural state of its environment amounted to damage. However, the actual claim for compensation related only to the restorative measures taken and no claim was advanced in respect of detrimental alteration of environmental quality per se.36

In the Gabčikovo-Nagymaros Case,37 the Hungarian claims for compensation for damage posed by the unilateral diversion of the waters of the Danube included the risks of damage to the aesthetic values and biological equilibrium of what it described as a unique ecosystem. It called upon the Court to take these non-use values into account in calculating the amount of reparation due to it.38 It invited the Court to consider relevant municipal law precedents and the practice of the United Nations Compensation Commission in its calculation of the amount of compensation. Slovakia, on the other hand, denied that international law provided any mechanism for compensating unproven and unsubstantiated damages which were based purely on hypothetical risks.39 The Court, having found both parties to be in breach of their respective obligations, did not award compensation to either, and the issue of compensation for pure environmental damage was thus left undecided. Instead the Court called upon the parties to settle any outstanding issues through bilateral negotiations.40

Despite considerable support for extending damage to include alteration of environmental quality in the literature,41 it is suggested that there is no evidence to support the existence of the right under general international law. The main treaties in the environmental field, with the exception of the Antarctic Mineral Resources Convention,42 limit compensation to identifiable loss to persons, property, or reasonable expenses incurred to clean up or restore the damaged environment.43

(p.179) The position in relation to radioactive contamination was considered in Chapter 4. There it was argued that, in principle, mere involuntary receipt of radioactive pollutants may be a proper object of claim. However, the rationale of this lies in the fact that significant damage can be presumed in cases of exposure to radioactive particles. It therefore does not necessarily contradict the position taken that the mere alteration of an environment's quality without more is not actionable in contemporary international law. There is, of course, undeniable merit in treating environmental quality as a good in itself, however its justiciability must await developments in international law, and in particular an appropriate formula for evaluating the detrimental factor. At the present time it is suggested that detrimental alteration of environmental quality as a distinct form of damage must be treated as an expression of concern rather than the basis of justiciable claims.

Three other items of damage that deserve further consideration include precautionary measures taken with a view to mitigating the harmful effects of transboundary pollution, clean-up costs, and prospective or future losses. It cannot be doubted that if the European states affected by the Chernobyl nuclear accident were to bring claims, a substantial part of this would relate to the ameliorative measures taken in the wake of the disaster, and prospective future losses since radiation injuries tend to be latent. These items of loss are considered in some detail later in this chapter. However, because of their close relationship to issues of causation, and in particular problems of remoteness of damage, they will be discussed after some analysis of the legal rules relating to proximate causality.

6.3. The Causal Element in Claims for Loss or Damage

(i) The Proximate Causality Test

It is necessary to consider in some detail the conditions for responsibility where a state has suffered material loss or damage as a result of transboundary air pollution and seeks redress for such injury. The evidence will be drawn from the decisions of international tribunals, but in so far as international and municipal tribunals employ similar principles in approaching issues of causation, reliance will also be placed on the approaches of municipal Courts.44 The decisions of municipal Courts in this context, it is suggested, may qualify (p.180) as general principles of law within the meaning of Article 38(1)C of the ICJ Statute.

International tribunals generally hold that the imposition of responsibility depends on a causal connection between the breach of an obligation by a state and the injury suffered.45 Primarily, this requires the existence of a cause and effect relationship in accordance with scientific or objective notions of physical sequence.46 The proposition nevertheless requires some qualification. In the literature and in the jurisprudence of international tribunals, it is frequently stated that only those losses that are proximately linked to the delictual conduct call into question the responsibility of the state.47

Two tests are usually employed in the determination of proximate causality. The first is objective, and depends on the existence of a proximate link between loss and the delictual conduct, as a normal and natural consequence of it.48 Referring to the practice of international tribunals, Brownlie concludes that governments can only be held responsible ‘for the proximate and natural consequences of their acts’, denying compensation for remote consequences ‘in the absence of deliberate intention to injure’.49 Graefrath also notes that ‘it is a principle of private law that is applied, the principle of “proxima causa”. A loss is regarded as a normal consequence of an act if it is attributable to the act as a proximate cause’.50

The normality test was applied by the Greco-German Mixed Arbitral Tribunal in the Antippa Case. The tribunal observed that

According to principles recognised both by municipal and by international law, the indemnity due from one who has caused injury to another comprises all loss which may be considered as the normal consequence of the act causing the damage.51

The test was also employed in the War Risk Insurance Premium Claim. The tribunal noted that

(p.181) It matters not how many links there may be in the chain of causation connecting Germany with the loss sustained, provided there is no break in the chain and the loss can be clearly, unmistakably and definitely traced link by link, to Germany's act.52

The second test is subjective, and involves a factual appreciation of the situation, as well as a policy choice as to which of the consequences of a defendant's act should attract responsibility. It proceeds on the premiss that injury is a logical consequence of an act, if in the opinion of the tribunal, the concatenation of events could have been foreseen by the defendant. This test finds support in the literature,53 the practice of states,54 as well as the jurisprudence of arbitral tribunals.

In the Portuguese Colonies Case, the arbitral tribunal employed the foreseeability test and held Germany liable for all the damage which it could have foreseen, even though the link between the unlawful act and the actual damage was not really a ‘direct’ one.55 The Samoan Claims Case, on the other hand, incorporated both a normality and foreseeability criterion in its formulation of the causality test. It held that a wrongdoer was liable for damages ‘which are both in fact, caused by his action, and could not be attributed to any other cause, and which a reasonable man in the position of the wrongdoer at the time would have foreseen as likely to ensue from this action’.56

Thus, proximate causality as a test would seem to exclude damages which, while linked to an unlawful act, are not close to it in time or in the causal chain. The subjective criterion would exclude those losses which could not have been foreseen as likely to ensue from the delictual conduct. In practice, the normality and foreseeability criteria operate alongside each other in determining losses that are deemed the proximate consequences of the delictual conduct. Damage may still be proximate even if in the chain of causation there are some intermediate links, if it was nevertheless a foreseeable consequence of the delictual act.57 This means that, normality while a relevant criteria is not necessarily conclusive and tribunals have not hesitated to exclude losses which although traceable directly to the delictual conduct were nevertheless too remote a consequence of the impugned act. Thus, the determination of proximate causality rests on objectively determinable facts, but this nevertheless is supplemented by a foreseeability criterion,58 the application of which rests on factual as well as considerations of legal policy.

(p.182) These principles of causality were applied by the arbitral tribunal in the Trail Smelter Case.59 They were also relied on by Canada in its claim against the Soviet Union for damage caused by the Soviet Cosmos 954.60 The application of these principles in the Trail Smelter Case is given some extended treatment below given its unique place in the law on transboundary harm. It also illustrates the application of causal principles to a concrete dispute on transboundary air pollution.

In relation to the Canadian Cosmos claim, Canada limited its claim to those consequences that could be regarded as reasonably proximate.61 The payment of compensation by the Soviet Union was made ex gratia, and did not as such involve a formal consideration of the operative legal principles. It is nevertheless significant that, in the opinion of Canada, the general principles of international law applied in the determination of causation. In Gabčikovo-Nagymaros, Hungary limited its claims for compensation to those forms of damage that it regarded as causally linked to Slovakia's breach of its treaty obligations.62

(ii) Proof of Causation in the Trail Smelter Case

The proof of causation in a bilateral dispute is relatively straightforward when compared to one involving multiple actors as is the case in long-range pollution. The limited number of parties, the clear identity of the source of harm, and the injured state usually mean that the normal causal principles can be applied without much distortion. This much is clear from the decision of the arbitral tribunal in the Trail Smelter Case.

As is well known, the dispute raised the question of the responsibility of Canada for the activities of a Canadian incorporated company, that had through the emission of sulphur fumes caused damage to property in the United States. Three questions were submitted to the tribunal, the first of which required it to determine: ‘Whether damage caused by the Trail Smelter in the state of Washington has occurred since the first day of January, 1932, and if so what indemnity should be paid therefore?’63 The case was nevertheless an easy one as far as the determination of a relationship of cause and effect is concerned. The pollution was notorious, and in a previous claim referred to it, the IJC established under the 1909 Boundary Waters Treaty had reached the conclusion that the pollution from the smelter was responsible for damage in the Washington area.64 There was also evidence before the tribunal that the damage caused by the emissions had been the subject-matter of previous litigation in the local County courts, forcing the smelter owners to purchase smoke easements from the local farmers.65

(p.183) Nevertheless, the tribunal set out to determine for itself the exact causal relationship between the emissions from the smelter and the damage caused. It relied on the automatic sulphur dioxide recorders installed by each of the governments, and evidence from United States and Canadian scientists. It reached the conclusion that certain damage had been done to the property as a result of the sulphur fumigations. It is important to note that the tribunal did not dismiss the case on the ground that the scientific evidence was inconclusive, instead it sought to determine for itself, on the evidence before it, the damage which could be causally attributed to the sulphur fumigations.66

The Tribunal accepted as proved the existence of a causal relationship between the sulphur emissions and the reduction in crop yield, as well as damage to forest trees. The claims of the United States that the sulphur emissions had resulted in the impairment of the soil contents through increased acidity, reduction of livestock, milk, and wool productivity were rejected as having an insufficient causal connection with the sulphur fumigations.67

The tribunal also rejected claims by the United States, which although causally linked to the sulphur fumigations were nevertheless too remote a consequence. The United States had claimed damages for ‘loss of business and impairment of the value of good will because of the reduced economic status of the residents of the damaged area’.68

It is also important to note that the tribunal did not insist on absolute certainty of proof, but was instead prepared to draw liberal inferences from the available facts.69 It quoted with approval the following passage from the decision of the United States Supreme Court in Story Parchment Company v. Paterson Parchment Paper Company 70 where that Court had observed that

Where the tort itself is of such a nature as to preclude the ascertainment of the amount of damages with certainty, … it will be enough if the evidence shows the extent of the damages as a matter of just and reasonable inference, although the result be only proximate.71

The case illustrates the relevance and the application of general principles of international law in the context of a localized or bilateral dispute. It also demonstrates the methods that can be employed to distinguish consequences that are remote from those that are proximate. The application of the same principles to long-range pollution on the other hand presents enormous (p.184) difficulties in view of the cumulative character of pollution and the multiplicity of parties involved.

(iii) Possible Difficulties in the Application of Traditional Concepts: Some General Observations

Most of the case law applying the proximate causality rule have been concerned with injury to the person or property of aliens, diplomats, or identifiable losses arising out of acts of war.72 In these instances the link between the delictual conduct and losses incurred is usually clear, and when multiple parties are involved the harm divisible. The application of causal principles to transboundary air pollution on the other hand raises serious difficulties in view of the ‘cumulative’ character of pollution injuries, the indivisibility of the resultant harm, and their link to a number of disparate activities usually in different source states.73

Two problems of a general kind arise in the determination of a cause/effect relationship. The first involves establishing a causal nexus between the loss or damage, and the delictual conduct attributable to a state. Scientific uncertainty and the cumulative nature of the processes of degradation make it difficult to determine the precise time or place of the damage attributable to a particular state or states. For instance, where a state has failed to observe a binding international standard (for example, the reduction of sulphur emissions by 30 per cent or ambient air quality standards under EEC Regulations), it may be presumed that the failure to comply with the standard has some causal relationship to the harm. But this presumption can only be made if it can be shown that the injury occurred after the adoption of the standards became legally mandatory. Yet, given the cumulative nature of the injuries, it may indeed be impossible to prove the precise time or period for which the state is to be held responsible. A state may have abandoned polluting activities for a considerable period, and pin-pointing its responsibility to a time previous to the abandonment of the activity is an arduous task that cannot be done without distorting the normality and foreseeability tests of causation. Moreover, given the complicated atmospheric processes which pollutants undergo before causing damage in the form of acid precipitation, proof of causation may require some modification of the traditional principles in this field.

In the case of nuclear pollution, causation issues are complicated by the latency of radiation injuries, making it difficult to establish a temporal or (p.185) spatial connection with the delictual conduct. Moreover, uncertainty surrounding radiation-induced injuries such as genetic and foetal damage and the many indirect ways in which exposure can occur, make it difficult to insist on a strict causal principle as the basis of responsibility.74

The second difficulty involves the apportionment of responsibility between the multiple contributing factors. This may include a number of states in the position of tortfeasors, the complainant state, and any other causal factors.75 Should states in the position of multiple tortfeasors be held responsible for their relative causal contribution,76 or should any of them be held jointly and severally responsible for the entire amount of loss forming the subject-matter of claim as is the case in most municipal legal systems?77 The next two sections will discuss the possible legal approaches to the issues raised. The exercise is essentially one of progressive development of the law in view of the paucity of legal writings on the issue or international claims based on joint or several responsibility of states.78

In establishing the causal relationship in a multiple cause/party situation, as in the case of losses attributable to air pollution, it is important to bear in mind that much will depend on the precise facts presented before a tribunal. The general principles suggested below are at best a guide, but their application in any concrete situation involves a large measure of appreciation of the facts and policy choices, best left to the tribunals or negotiators.79

(iv) Causation and Long-Range Transboundary Air Pollution

Professor Schachter has adverted to the problem under consideration. He notes that, ‘liability is only a feasible mechanism when damage is identifiable, traceable to a state of origin, and reasonably foreseeable by that state’.80 From this premiss he argues that injuries of the long-range pollution type are (p.186) best dealt with through extra-judicial means, since proof of causation and apportionment of responsibility between various polluting states is neither realistic nor possible. This view was no doubt influenced by the then prevailing scientific opinion that in so far as it was impossible to determine the contribution of a particular state to the harm resulting from long-range pollution, traditional principles of responsibility had no application. The more recent evidence emerging from the work of EMEP in fact suggests that it is possible to determine the approximate contribution of particular states to the total sulphur or nitrogen emissions.81 Thus, although it is not possible to link damage suffered to specific sources in a particular state, using emission data it is possible to determine the relative causal contribution of states to the damage caused.

Other writers have taken the position that although a finding of responsibility is legally feasible, no practical value can be served by such a process. They cite the complex nature of the causal issues involved and argue that developments in international law, as well as the practice of states, do not support the imposition of responsibility.82 These writers therefore emphasize the strengthening of co-operation and other non-judicial methods of monitoring compliance. Whilst not dismissing the concern of these writers, the position taken in this work is that there is still a proper place and role for state responsibility. The imposition of responsibility serves a crucial deterrent function and puts a hard edge on rights. As is argued in Chapters 7 and 8, it should be seen as complementary to the other non-judicial techniques of enforcing compliance.

In Chapter 1, it was noted that the multiplicity of sources of sulphur and nitrogen emissions, the capacity of pollutants to travel thousands of miles to different states, and their chemical transformation in the course of transport pose an enormous challenge to the rules of causation as generally understood. Moreover, the emissions not only emanate from identifiable or discrete activities (such as industrial sources) but also from routine activities such as the use of automobiles and domestic heating, the contribution of which is not easy to identify.

Furthermore, and assuming that a source state can be identified, it must be remembered that the losses or damage usually attributed to long-range pollution are the result of a process of high causal complexity involving many factors. Scientific reports in fact concede that the damage to European forests (p.187) is probably due to a number of factors of which air pollution is only one.83 A 1989 Forest Damage Survey was conducted in twenty-seven European states. The results indicate that in eight countries air pollution was the principal destabilizing factor, but in the other nineteen countries air pollution was only one of the many factors contributing to forest damage.84 This raises the very difficult task of apportioning causation between the different factors capable of giving rise to the loss.85

Several cases noted in Chapter 1 illustrate the complexity of the problem under discussion. In Switzerland and Austria less than 15 per cent of sulphur deposited in 1980 came from domestic sources. The records indicate that the rest is attributable to other European states.86 In case of proven damage to Swiss/Austrian lakes or forests, how is responsibility to be apportioned between these sources? Similarly, it has been estimated that 200,000 tonnes of sulphur have been deposited in Norway annually from 1980 to 1984; of this total only 10–20 per cent was reported to be related to sources in Norway.87 Apart from the determination of causation between the contributing factors, there is also the issue of apportioning the damage between the states involved. In other words, a relationship of multiple responsibility arises with respect to the damage.

How is causation to be determined in these instances? Proof on a balance of probabilities or on a sine qua non basis may not be possible. Yet to allow the evidentiary difficulties to preclude responsibility would greatly undermine the objectives of the primary rules. There is therefore a case for arguing that in these instances a tribunal should be allowed to act upon probable and inferential evidence as well as direct and positive proof.88 In relation to complex causation cases in other contexts, international tribunals have not been unduly concerned with the formal requirements of evidence, and are generally prepared to draw liberal inferences from the facts presented.89 It nevetheless remains an open question whether international tribunals would be prepared to rely on inferential evidence of this form as a basis for responsibility when faced with a clear case of damage attributable to long-range pollution.

(p.188) (v) Material Contribution to Risk

It is suggested de lege ferenda that the problems posed by long-range pollution require courts to take a broad view of causation, and in principle a state should be held responsible if on the facts it can be established that its conduct materially contributed to the damage suffered by the plaintiff, even if other factors and causal agents also enter into the equation. The apportionment of responsibility between the many contributing factors will depend on the facts presented before the tribunal. A similar approach to the one suggested has been adopted by most municipal systems.90 It is therefore instructive to look at their jurisprudence.

English Courts have generally taken the view that a defendant is liable where his breach of duty has caused, or materially contributed to, the injury suffered by the plaintiff.91 In the leading case of McGhee v. National Coal Board,92 the House of Lords held that, where a plaintiff contracted dermatitis which was work related, he could discharge the burden of proof incumbent on him by demonstrating that the work condition materially increased his risk of contracting the disease. In other words, where the harm is indivisible and attributable to a number of possible causes, positive proof of causation is dispensed with.93 Lord Wilberforce was of the view that as a matter of policy or justice, the inherent evidentiary difficulties should be born by the party who has created or materially increased the risk of harm to the plaintiff.94

In the United States, the evidential burden on the plaintiff in ‘multiple causation’ cases has been relaxed by the application of a similar doctrine.95 Under the ‘market share’ doctrine, a defendant's liability in product-related injuries may be established by proving that he held a substantial percentage of the market share of the product.96 The share of the market raises a presumption that the defendant's products contributed to the risk suffered by the plaintiff. The policy underlying this doctrine, as Dr Stapleton points out, is not dissimilar to material contribution to risk discussed above.

(p.189) The Restatement of the law of Torts also adopts a material contribution to risk test, where the defendant's conduct is one of a number of causes that contributed to the plaintiff's condition. According to the Restatement, the conduct or event in question is a cause in fact of the harm if it is a substantial factor in producing it, or makes ‘a material contribution to it.’97

Municipal Courts therefore do not hesitate to depart from strict causal rules, where the circumstances of the tort make it difficult to establish a cause/effect relationship.98 The proposition finds some support in the recent report of the ILA. The Committee on Legal Aspects of Transfrontier Air Pollution has stated that, in so far as every exposure contributes to the deterioration of the environment in the claimant state, states responsible for transboundary air pollution can either be held responsible on the basis of individual causal contribution to the risk or for the totality of loss in accordance with the principle of joint and several responsibility.99 In each case a but for test is not applied.

It has already been noted that the scientific opinion emerging from the work of the (‘Co-operative Programme for the Monitoring and evaluation of the Long-Range Transmission of Air Pollutants in Europe’ (EMEP)) indicates that the contribution of particular states to overall pollution as well as areas of deposition can be estimated using models.100 Such evidence should be treated as prima-facie proof that the activities of a particular state (A) contribute to forest damage in state (B). Ultimately, much will depend on the precise facts adduced before the international tribunal, as well as the incidence and burden of proof. The complexities in the identification of responsible states and proof of causation are inherent in the liability approach to environmental protection, but they should not be a basis for dismissing claims in their entirety.101

That responsibility should be based on material contribution to risk was effectively argued for by the Government of Australia in the Nuclear Tests Cases. The Australian case rested on the premiss that any additional exposure to radioactive contamination, no matter how small, substantially contributed to the risk of radiation-related injuries.102 Counsel for Australia argued that additional exposure to radiation was in fact proof that Australia had suffered or would suffer damage at some future point. Thus, in the opinion of Australia, material contribution to risk was an appropriate basis for the (p.190) imposition of responsibility. The Court did not decide on this point or any other issues pertaining to the merits of the Australian application, having found instead that the object of the application had disappeared as a result of the French undertaking to discontinue further atmospheric nuclear tests.

Nevertheless, it is suggested that in principle, a state that emits pollutants beyond that which is normally regarded as tolerable must be presumed to have materially contributed to the damage suffered by the victim of such pollution. Moreover, as between source and victim states, the ends of justice can only be met if the inherent evidentiary difficulties are borne by the source state.

6.4. Heads of Damage of Specific Relevance to Air Pollution

(i) Probable and Future Damage

This head of damage is bound to play a significant role in air pollution related claims. The Australian Memorial in the Nuclear Tests Cases raised the issue of the extent to which probable or future damage may be recovered in international law.103 The latency of most radiation injuries and the long-term somatic and genetic effects of low doses of radiation means that actual damage may not be identified until long after exposure.104 Moreover, as UNSCEAR has pointed out, although additional exposure to radiation increases the risk of contracting cancers, such future malignancies may in fact not be distinguished from those due to other factors.105 Should responsibility be based on the statistical probability that given a certain level of exposure to radiation a substantial degree of harm is inevitable? Should causation be presumed where future losses, although not quantifiable, can nevertheless be predicted with a reasonable degree of certainty?

In principle, there is no reason why prospective damage cannot be the basis of responsibility if it is reasonably anticipated. Although not making any claims for damages, the Australian argument in the Nuclear Tests Cases in fact proceeded on the premiss that prospective harm to the Australian population could be calculated with a reasonable degree of accuracy based on the degree of exposure to radiation.106 In the Gabčikovo-Nagymaros Case, Hungary maintained that future damage was an appropriate basis for reparation. Referring specifically to the alleged ecological risks posed by Slovakia's unilateral diversion of the waters of the Danube, Hungary noted that the

damming of a massive international river is precisely the type of hazardous situation that entails potential damage the full extent of which cannot be demonstrated at this (p.191) time … reliance on probabilities must therefore play a necessary part in the reparation process. The creation of potential risks by a state, which involve a threat to the future of entire populations across international borders constitutes international damage and is likely to generate material consequences. These material consequences deserve adequate reparation, to be determined either by the parties in conformity with the Court's decision.107

Hungary argued that compensation of future damages was a logical application of the precautionary principle.108

In municipal systems tribunals routinely proceed on the premiss that damages can be awarded to take into account prospective pain and suffering, prospective loss of amenities, and prospective loss of earnings.109 A case may therefore be made for the application of similar principles under the rubric of general principles of law recognized by civilized nations.110

Thus the states exposed to increased cases of cancer and other malignancies as a result of the Chernobyl nuclear accident could in principle have obtained compensation, even if the precise extent of damage could not immediately be determined.

(ii) Precautionary Measures and Clean-up Costs

The physical contamination of the environment may necessitate the evacuation of the population from the affected areas as a precautionary measure against further exposure. The affected state may also mount clean-up operations to mitigate against any further contamination. The issue is of immense practical importance since most of the losses likely to be incurred as a result of accidental air pollution relate to evacuation, restrictions on food consumption, as well as clean-up costs. A substantial amount of losses incurred in the wake of the accident at Chernobyl plant and the damage caused by the Soviet Cosmos 954 were the direct result of precautionary measures adopted by the affected states.

In principle, the question whether such losses should be recoverable or not simply depends on ascription in accordance with ordinary causal principles. Nevertheless, the issue requires further investigation in view of the special importance of these items of loss in the environmental context, and the limited nature of the case law having a direct bearing on the issue.111

(p.192) In the Soviet Cosmos Case, it was noted that Canada claimed from the Soviet Union the sum of US$6,041,174.70, being the total cost of precautionary and clean-up operations undertaken to mitigate the harmful consequences of the intrusion of the Soviet satellite into Canadian airspace.112 The statement noted in part that under general principles of international law Canada was under a duty to mitigate the harmful consequences of the scattered debris. It noted that the operations were undertaken to identify

the nature and extent of the damage caused by the debris, to limit the existing damage and to minimize the risk of further damage and to restore to the extent possible the affected areas to the condition that would have existed if the intrusion of the satellite and the deposit of debris had not occurred.113

Thus, it is implicit in the Canadian statement that Canada regarded precautionary and restorative measures as recoverable, being reasonable measures taken in mitigation of loss. Although the final payment by the Soviet Union was made ex gratia, it is nevertheless a persuasive precedent in support of the recoverability of precautionary measures, for Canada had in addition to treaty obligations expressly grounded its claim on existing principles of general international law.

In the case of the Chernobyl nuclear accident, it has already been noted that the bulk of the losses suffered by the European states were the direct consequence of precautionary measures adopted by the states individually, and also under the auspices of the European Communities. These measures included a ban on imports from certain European countries, and regulations as to the maximum permitted levels of radioactivity in foodstuffs and agricultural products.114 As a result, many farmers incurred substantial losses. A number of governments paid their farmers for the losses incurred following the ban on the sale of contaminated food.115 The question that merits further treatment is whether these payments to the farmers, as well as other precautionary measures taken, can be recovered as proximate losses flowing from the Chernobyl accident. In Chapter 4 it was noted that no formal claims for compensation have been put forward by the European governments, and the (p.193) Soviet Union has emphatically denied the existence of any causal connection between precautionary measures taken and the accident.116

In principle, and assuming causation has been proved, compensation should be paid for precautionary measures and clean-up costs.117 In the Trail Smelter Case the tribunal had no difficulty with above proposition as a matter of law. It observed that expenses incurred in mending the consequences of an injury were recoverable as an appropriate head of damage. It nevertheless rejected the United States claim for recovery of moneys spent on investigation, preparation, and proof of its case. The tribunal observed that these expenses were incidental to the normal conduct of litigation and could not therefore be treated as separate items of loss.118 In other words, the expense incurred must itself be related to the principal damage.

International arbitral tribunals in other contexts have been less reluctant to allow recovery for expenses which are incidentally and reasonably incurred on account of the principal damage or wrong. Medical and hospital expenses have been routinely allowed in claims arising from injuries to the person.119 Reimbursement has also been allowed for expenses incurred in repairing or replacing property damaged by a wrong.120 In the Alabama Claims the first Court of Commissioners allowed owners of vessels interfered with, damages for extraordinary expenses incurred because of wrongful interference.121

Similarly, in the William Lee Case the United States-Peruvian Commission awarded damages in the amount of $22,000 for the unlawful detention of the vessel, including $4,000 for repairs, and $1,500 for all expenses incurred during detention.122 Indeed, one can conclude from Whiteman's comprehensive survey that arbitral jurisprudence largely supports the reimbursement of expenses incurred as long as they are proximately connected to the principal damage.123 In principle, it is suggested that no meaningful distinction can be sustained between medical expenses or costs of repair on the one hand and precautionary or clean-up costs in a pollution context on the other.

A number of instances in the environmental context may also be cited in support of the general recoverability of clean-up costs and precautionary measures. The payments made to the governments of the United Kingdom and France by the shipowners and charterers following the Torrey Canyon disaster also included clean-up expenses.124 The evidence from Conventions (p.194) on civil liability for oil pollution damage is further support for the proposition that preventive costs and clean-up measures can legitimately be regarded as recoverable heads of loss under international law, being proximate consequences of pollution. Under the 1969 Convention on Civil Liability for Oil Pollution Damage,125 damage is defined to include ‘the cost of preventive measures and further loss or damage caused by preventive measures’. The definition of nuclear damage contained in the 1997 Protocol to the Vienna Convention on nuclear damage expressly refers to costs of preventive measures.126

Reference may also be made to the experience of municipal courts. In the legal systems of the common law family it is an accepted rule of law that the victim of a wrong is under a duty to mitigate his loss.127 As a corollary all expenses incurred by the plaintiff in mitigation are recoverable, as long as they are necessary and reasonable.128 The rule is so widely applied, that it may be regarded as a general principle of law recognized by civilized nations.129 Preventive and clean-up costs are essentially measures taken in mitigation, and in principle they should be recoverable as long as they were necessary and reasonable.

There is in any case considerable support in the literature for the view that expenses incurred in the prevention of damage or the restoration of damaged property ought to be recovered.130 Thus, Whiteman notes that expenses incidentally and reasonably incurred on account of the principal damage must be reimbursed as an item of loss.131 García Amador reaches a similar conclusion, noting that reparation must extend to the expenses incurred by reason of the injury sustained.132

Finally, a fundamental consideration of policy should prevail. It is worth remembering that the particular rules of substantive law applicable to air pollution are primarily directed at the prevention of harm. It would defeat the general purpose behind the rules if a tribunal were to hold that preventive or clean-up costs are too remote a consequence of delictual pollution. The (p.195) concept of loss must not be divorced from the broad policies underlying a rule.

If it is accepted that expenses incurred in mitigation of loss are recoverable only if they are ‘necessary and reasonable’, it may be asked whether the European states can recover for the losses incurred by their farmers as a result of governmental intervention following the Chernobyl nuclear accident? It is suggested that this turns on whether the measures can be deemed reasonable in the circumstances. Yet the determination of reasonableness is not without difficulty in the absence of internationally agreed standards on the maximum permitted levels of radiation in the environment or in agricultural products. The contamination levels justifying intervention varied considerably between European states.133 The most cautious states in fact exceeded the generally recommended limits for radionuclide contamination of foods.134 The progressive development of this area of the law thus requires some consensus on what constitutes ‘necessary’ or ‘reasonable’ measures of mitigation or prevention. However, in the absence of such agreement, it is suggested that de lege ferenda European states may still be able to recover for the losses incurred, if they can demonstrate that the actions taken were such as could be expected of a reasonable government faced with a real risk of irreversible damage.

6.5. Responsibility and Multiple State Actors

So far the discussion has been largely concerned with the rules and principles for determining causation, as well as the applicable heads of damage in the context of claims for loss caused by transboundary air pollution. It is now necessary to consider the principles which govern the apportionment of responsibility when the harm suffered by a state is traceable to a plurality of source states. It may be stated at the outset that international law has not developed sophisticated rules and procedures for adjudicating and apportioning responsibility between states in the position of multiple tortfeasors. Issues of responsibility in international jurisprudence have largely been concerned with bilateral disputes between no more than two parties. Moreover, the wording of the Statute of the International Court also envisages disputes between two states.135 Furthermore, in the literature, there is hardly any (p.196) discussion of the principles to be applied in those cases where impermissible harm is the result of delictual conduct on the part of a number of states.136

This immediately raises a problem for air pollution, which, it was noted, is a cumulative problem, usually the end result of delictual conduct on the part of several states. In many cases the victim of pollution is also invariably a contributor to the harm complained of. The situation is further complicated by the fact that although the states whose delictual conduct is in question may have acted independently, the harm suffered is unitary.

The problems that arise in this context are both procedural and substantive. The procedural problems primarily relate to the consensual nature of international adjudication, and as a corollary that no claim may be brought against a state without its having consented to the jurisdiction of the International Court or other arbitral tribunals. As the Court has pointed out in its recent jurisprudence, it lacks a procedure known to municipal systems whereby parties may be compulsorily joined to a dispute if they are implicated in delictual conduct.137 A state victim of pollution then has the unenviable task of finding a jurisdictional basis for bringing a claim against each one of the parties. Failing that it may only bring a claim against those states which have accepted the jurisdiction of the Court. Serial litigation in this form is not only cumbersome for the parties; it also occupies the Court unnecessarily and may lead to conflicting judgments on the same facts. The Court may in any case decline jurisdiction under the indispensable parties rule, if it concludes that the dispute involves a number of parties not before it, and cannot therefore be determined without adjudicating on the rights and obligations of third states.138

It is true that in some cases the indispensable parties rule has not been insisted upon, and the International Court has been prepared to settle disputes, even if theoretically the disputes also involve the rights and obligations of third states not before it. In the Nauru Case, Nauru was permitted to bring a claim against Australia for breach of a trusteeship agreement, even though Australia had acted as joint trustee with the United Kingdom and New Zealand, yet the other two states were not joined as parties to the dispute.139 (p.197) The Court has taken the position that although it is desirable that multiple party claims should be settled in the presence of all the parties involved, this is not always possible in the international context as there are no procedures for compulsory joinder of parties.140 In these circumstances a state victim of pollution is in principle free to proceed against some of the parties only, even if the harm suffered is attributable to others not party to the dispute.

It is suggested that given the limited number of cases in which the International Court has countenanced the possibility of dispensing with the indispensable parties rule in multiple disputes, it would be premature to conclude that the Court will in most cases be prepared to hear claims implicating states that are not directly parties before it. The logic of the indispensable parties rule must at the present stage be taken as an inescapable element of the bilateral character of international adjudication. The context in which the International Court will be prepared to hear claims involving multiple parties not before it must of the present moment be regarded as exceptional.

What is to be the position if a state victim of transboundary air pollution were to bring an action against only one of the parties, in a situation where it is undisputed that part of the damage was attributable to states not party to the dispute? In other words, may states be held jointly and severally responsible for indivisible harm?

In the Nauru Case, the Government of Australia denied that international law recognized a concept of joint and several liability as known to municipal systems. Australia had argued that, since it had acted jointly with the United Kingdom and New Zealand, the Court could only determine their potential liability jointly, with the result that action could not be brought against Australia alone.141 The Court ruled that in principle there was no reason why Nauru could not bring an action against Australia alone. It nevertheless left for consideration at the merits phase the form of Australian responsibility, in particular whether it would be joint and several or based only on its proportionate share of blame.142 However, since the case was discontinued and settled, it cannot be presumed that the Court would have upheld the existence of the principle of joint and several liability in international law.143 Furthermore, it is in any case unclear whether responsibility in these instances should instead be grounded on individual causal contribution. The issue deserves some extended consideration before a progressive regime in this area of the law is suggested.

(p.198) (i) Municipal Practice

Given the scarcity of direct judicial treatment of multiple defendant cases in international law, it is necessary to look at the approaches taken by municipal tribunals. The principles applied by municipal Courts may under certain conditions qualify as general principles of law within the meaning of Article 38 1(C) of the statute of the International Court. The practice may also be relevant in the formulation of a progressive regime of international law applicable to the same problems.

There is evidence to suggest that the majority of civil and common law systems favour liability in solidum, where the defendant's conduct along with that of others has contributed to damage in circumstances where the damage is indivisible. Both systems hold any of the tortfeasors liable for the entire loss as long as the harm is indivisible.144 The plaintiff may sue all or any of them for the full amount of his or her loss, and the liability is joint and several. The rule is prompted by a desire to afford the victim of the harm the maximum possible chance of having his loss properly and fully compensated.

The harshness that the rule may lead to has been mitigated by a statutory right of contribution as between tortfeasors in both Civil and Common law systems.145 The apportionment of responsibility in any subsequent action for contribution is determined either on the basis of relative causation or blameworthiness (or both).146

In principle, it would seem that cumulative pollution caused by independent actors does not as such present a unique problem to municipal systems. Once it is determined that a number of tortfeasors acting independently contributed to a single indivisible harm, any of them can be held liable for the entire amount in accordance with the principle of joint and several liability. The principle has been directly applied by the United States Courts in a case of transboundary air pollution. In Mitchie v. Great Lakes Steel, the US Sixth Circuit Court of Appeals held three United States defendants jointly and severally liable to Canadian plaintiffs for nuisance due to emissions from the defendants' plants. The defendants were left to apportion among themselves the contribution of each to the overall loss.147

(p.199) (ii) International Jurisprudence

The international legal system, on the other hand, lacks such clearly developed rules. Moreover, it is unclear whether the principle of joint and several responsibility as known to systems of municipal law can be transplanted on to the international plane as a ‘general principle of law’.148 It has been noted that one of the cardinal principles of international adjudication is that the Court should decline the settlement of a claim if the dispute presented to it also involves the determination of the responsibility of a third state not party to the dispute.149

It is difficult to see how the principle of joint and several responsibility can be applied on the international plane without offending this principle. To hold State A responsible for pollution damage in part attributable to States B, C, and D would in principle involve a determination of the responsibility of those states. Thus the solution, although attractive, raises some difficulties of practical application. In any case the principle of joint and several liability in the municipal sphere is supported by special mechanisms, usually statutory for obtaining contribution from the co-defendants. The international system on the other hand has not developed similar procedures.150

A limited number of international cases have adverted to the problem of apportionment of responsibility in multiple defendant situations. Reference is usually made to an obiter dictum of the United States Court of Claims in Anglo-Chinese Shipping Co. Ltd v. United States.151 The case involved an action brought by a British shipping company against the United States for the use of the company's vessel during the Allied occupation of Japan.

The United States resisted the action on the ground that the use of the plaintiffs vessel was a use by all the occupying governments, and that a suit could be maintained only against the group and not the individual governments. Although the Court of Claims decided that the actions of the Supreme Allied Commander were attributable to Japan, and not the United States or the Allied powers, in an obiter dictum of some interest the tribunal observed that the place of joint or several liability in the international system has never (p.200) been decided, and that since the issue did not arise on the facts of the case, it was not necessary for it to definitively offer an opinion on the matter.152

Brownlie has suggested that in the Corfu Channel Case, the Court was untroubled by the possibility that another state (possibly Yugoslavia) had laid the mines in Albania's territorial waters.153 Thus, to the extent that another state was also responsible, the liability of Albania for the entire amount may point to some recognition of joint and several liability as between independent wrongdoers.154 The proposition also finds some support in the individual opinion of Judge Azevedo in the same case.155 However, caution is required in evaluating the precedent value of the case in this context, as the issue of joint or several liability was never addressed in the judgment of the full Court.

Determination of responsibility in the context of multiple party disputes has been discussed by the International Court in no fewer than four recent cases. In the Nicaragua Case, the Court observed that it did not possess the power to direct that a third state be made a party to the proceedings.156 It did not, however, discuss the question whether a state party before it could be held jointly and severally responsible where its conduct was partly responsible for harm suffered, but under circumstances where part of that damage could also be attributed to third states. Similarly, in the Nauru Case it has been noted that the Court rejected the claims of Australia; that the Court could only proceed with the case if the other parties, in this case United Kingdom and New Zealand, were also joined as parties.157 It nevertheless left open for determination at the merits phase the substantive issue of whether the responsibility of a state which has acted jointly with others in the commission of harm is joint or several, or partial based on individual causal contribution.158 However, a number of judges on the Court expressed some doubt as to the existence of joint and several liability in international law.159

Thus, it is clear that no definitive principles can be delineated from this limited international practice. Indeed, there is little evidence to suggest that international law already recognizes that in appropriate circumstances (p.201) responsibility may be joint and several. Such evidence as exists is far from conclusive. It is therefore suggested that the principles which ought to determine the apportionment of responsibility can only be suggested as part of the progressive development of the law.

(iii) Relative Causal Contribution

The problems inherent in joint and several liability have led writers who have considered the issue to favour apportionment on the basis of individual causal contribution.160 Thus, in formulating the proxima causa rule Eagleton observes that: ‘if other elements enter into the production of the harm alleged, compensation should be made in proportion to the damage caused by the respondents act.’161 Gray also reaches a similar conclusion. She observes that ‘if a state is liable only for the direct consequence of its own act it should not have to pay full compensation for injuries partly caused by external factors’.162 Schachter has also advocated the apportionment of responsibility on the basis of relative causation.163 In the same vein the Restatement notes that, ‘where more than one state contributes to the pollution causing significant injury,’ the liability will be apportioned among the states, taking into account where appropriate the contribution to the injury of the injured state itself.164

It is also significant that the draft article in the Sixth Report of the ILC on ‘Liability for Injurious Consequences of Acts not Prohibited by International Law’, which had provided for joint and several liability did not attract much support in the ILC.165 The debates in the Commission indicate that many members favoured the imposition of responsibility on the basis of individual causal contribution. In their view, it was unlikely that states would accept full liability for harm which was also caused or aggravated as a result of activities of other states in the absence of mechanisms for obtaining contribution.166

Assuming that responsibility is to be based on individual causal contribution, on what basis then is the responsibility to be apportioned where, as in the case of air pollution (especially from industrial or automobile sources), the resultant harm is indivisible? Again, there is little guidance in international jurisprudence, and the discussion that follows is largely made de lege ferenda.

(p.202) It has already been noted that in municipal systems claims for contribution between independent tortfeasors is settled on the basis of relative causation or blameworthiness. In principle, the international system could adopt a similar approach. States contributing to long-range pollution could be held responsible on the basis of relative causation or blameworthiness, having regard to all the circumstances and the evidence available.

A caveat must nevertheless be entered, for such apportionment is only possible if all the parties are before the Court or Tribunal. Of course, the Court could always restrict itself to the determination of the liability of those before it but, as noted before, it is an interesting question whether it can do this without offending the Monetary Gold rule.167 For to hold state A responsible for a proportion of loss suffered leads to the conclusion that the remaining proportion is attributable to other states.168 The opportunity was missed in the Nauru Case, and the possible solutions to these seemingly intractable problems must await further developments in international law.

Perhaps the fairest and most rational solution in this context is an agreement on principles for the apportionment of responsibility by states contributing to transboundary air pollution.169 A relevant example in this context is in the 1972 Convention on International Liability for Damage Caused by Space Objects. After providing for a regime of joint or several liability, the Convention at Article IV (2) provides that

the burden of compensation for the damage shall be apportioned between the first two states in accordance with the extent to which they were at fault; if the extent of the fault of each of these states cannot be established, the burden of compensation shall be apportioned equally between them.170

It is unfortunate that despite the proliferation of environmental treaties, including those on transboundary air pollution, there is as yet no evidence that states are willing to address some of the more difficult problems inherent in the state responsibility regime.


(1) I. Brownlie, Principles of Public International Law; 5th edn. (Oxford, 1998) at 435.

(2) Although issues of state responsibility may be settled diplomatically through inter-partes negotiations, the approach envisaged in this chapter is essentially judicial. It is true that few environmental disputes have been brought before international courts or tribunals, nevertheless the relevance of the imposition of responsibility for breach of air pollution obligations retains undoubted practical significance, and cannot be ignored. On 19 July 1993 the International Court issued a Communique (No. 93/20) announcing the establishment of a Chamber of the Court for environmental matters. The initial seven-member Chamber was composed of Judges Schwebel, Bedjaoui, Evensen, Shahabudeen, Weermantry, Ranjeva, and Herczegh. Whilst it may be premature to anticipate what forms of disputes the Court may be called upon to decide, it is not unreasonable to suggest that these may turn on responsibility for environmental damage. The mandate of the Chamber was renewed for a third term with Judge Fleischhauer replacing Judge Evensen: see ICJ Communique No. 94/10, 14 March 1994.

(3) On the distinction between the two categories of obligations see draft Articles 20 and 21 of the Articles adopted by the ILC at its Twenty-Ninth session, YBILC (1977) Vol. II (Part II) at 11–30.

(4) Article 2 of the Sulphur Protocol, 27ILM (1988) at 707 (in force 2 September 1987); see also Nitrogen Protocol 27 ILM (1988) at 698 (in force 14 February 1991).

(5) Protocol on Further Reduction of Sulphur Emissions (1994) 33 ILM, 1540.

(6) See Articles 20 and 21 of the draft Articles adopted by the ILC, n. 3 above.

(7) III RIAA at 1907–65.

(8) The nature of this duty and its legal implications has been given extended treatment in Chapter 3, see in particular pp. 65–78.

(9) Ago, Fifth Report on State Responsibility, YBILC (1976) Vol. II (Part I) at 22–4; Brownlie, State Responsibility, Part I (Oxford, 1983) at 193.

(10) I. Brownlie, State Responsibility, n. 9 above.

(11) YBILC (1978) Vol. II (Part II) at 89.

(12) ICJ, Reports (1980) at 3.

(13) Ibid, at 41–2.

(14) 82 ILR at 499.

(15) 82 ILRat 573.

(16) See Riphagen, Second Report on State Responsibility, YBILC (1981), Vol. II (Part I) at 88 at paras 76 and 83; Report of the Commission to the General Assembly on the Work of its Fortieth Session, YBILC (1988), Vol. II, Part II at 105 paras 538–9; Brownlie, State Responsibility n. 9 above at 194–5; C. Dominice, Droit International 2, Institut des Hautes etudes Internationales (Paris, 1982) at 1–27.

(17) Article 25 of the draft Articles on State Responsibility adopted by the ILC, n. 11 above.

(18) Rainbow Warrior Case, n. 14 above at 565; see also Separate opinion of Judge Cheng Tien-Hsi in Phosphates in Morocco Case, PCIJ. Series A/B, No. 74, Judgment of 14 June (1938) at 36–7.

(19) On the temporal element, see Brownlie, State Responsibility, n. 9 above at 194–5.

(20) M. M. Whiteman, Damages in International Law (Washington, 1937), Vol. I at 80–1; García Amador, Sixth Report on State Responsibility, YBILC (1961), Vol. II at 8–13; see also, Report of the ILC on the Work of its Forty-Second Session (1990) YBILC Vol. II (Part I) at 274; C. Gray, Judicial Remedies in International Law (Oxford, 1987) at 33–9; Brownlie, State Responsibility, n. 9 above at 222–9; ALI, Third Restatement (St Paul, Minn., 1987) Vol. II, Section 601 at 103. Notable cases in arbitral jurisprudence include Janes Case (1925) IV RIAA at 82; Trail Smelter Case, n. 7 above at 1925–34.

(21) For a survey, see Whiteman, Damages, n. 20 above.

(22) Convention on International Liability for Damage Caused by Space Objects, 961 UNTS 187 (in force 1 September 1972).

(23) UNTS Vol 1302,217.

(24) See the 1963 Vienna Convention on Civil Liability for Nuclear Damage, 2 ILM (1963) at 727; 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy, 69 UKTS Cmnd. 3755.

(25) Barboza, Sixth Report on Liability for Injurious Consequences of Acts not Prohibited by International Law, Commentary to Article 24, YBILC (1990) Vol. II (Part I) at 96; Sands, Principles of International Environmental Law (Manchester, 1995).

(26) WCED, Our Common Future (Oxford, 1987) at 348–9; A. Kiss and D. Shelton, International Environmental Law (London, 1991) at 144–54; G. Handl, ‘Territorial Sovereignty and the problem of transnational pollution’, 69 AJIL (1976) at 50–3; B. Smith, State Responsibility and the Marine Environment (Oxford, 1988) at 103–5.

(27) Smith, n. 26 above at 103; Handl, n. 26 above at 53; Orrégo Vicuna, ‘State Responsibility, Liability and Remedial Measures under International Law: New Criteria for Environmental Purposes’; in E. Brown Weiss (ed.), Environmental Change and International Law (Tokyo, 1992) at 124–8; Gabčikovo-Nagymaros Case (Hungary/Slovakia), Memorial of the Republic of Hungary Vol. I at 255–6.

(28) O. Schachter, International Law in Theory and in Practice (Dordrecht, 1991) at 367.

(29) Memorial of the Republic of Hungary, n. 27 above at 250–1, paras 8.22–8.26.

(30) (1978) Vol. I, ICJ Pleadings at 15 and 45; New Zealand arguments which are broadly to the same effect are in (1978) Vol. II, ICJ Pleadings at 8 and paras 210 and 213.

(31) Ibid, at 180.

(32) For more recent reports on the effects of radiation, see generally Report of the UNSCEAR 43, UNGAOR Supp. (No. 45), UN. Doc.A/43/45 (1988).

(33) Comité Interministériel Pour Lʼinformation, Livre blanc sur les experiments nucléaires at 20–1; in the 1995 Nuclear Tests Cases, France again maintained that there could be no responsibility under contemporary international law in the absence of proven damage; that international law did not as such impose responsibility for mere alteration in the quality of the environment, see arguments of M. Perrin de Brichambaut Counsel for France in New Zealand Ministry of Foreign Affairs, French Nuclear Testing in the Pacific (Wellington, 1996) at 207–8.

(34) See the joint dissent of Judges Onyeama, Dillard, Jiménez de Aréchaga, and Sir Humphrey Waldock, Nuclear Tests Cases, ICJ Reports (1974) at 63–118; see also dissenting opinion of Judge Sir Garfield Barwick, Ibid, at 142–84.

(35) 1961 UNTS, 187.

(36) 18 ILM (1979) at 902–30.

(37) 1997 ICJ Reports at 7.

(38) Memorial of the Republic of Hungary, n. 27 above at 253 and 255–6 and Reply of the Republic of Hungary, 20 June 1995.

(39) Counter-Memorial of the Slovak Republic, Vol. I, 5 December 1994 at 364, para 12.26.

(40) n. 37, para. 153 above. Unfortunately the parties have failed to arrive at an amicable settlement and have asked the Court to indicate the modalities of complying with its judgment, see Press Communique 98/28 of 3 September 1998 and Press Communiqué 98/31 of 7 October 1998.

(41) Boyle, ‘Nuclear Energy and International Law: An Environmental Perspective’, 60 BYBIL (1989) at 257 and 276–7; Schachter, n. 28 above at 367; Caron, 14 Yale J. Int. L at 528–9; Barboza, Sixth Report, n. 25 above. Draft Article 24; Orrego Vicuna, n. 27 above at 141.

(42) Article 8 (2), 27 ILM (1988) at 868.

(43) See (1969) Convention on Civil Liability for Oil Pollution Damage 973 UNTS at 3; The Tankers Owner's Voluntary Agreement Concerning Liability for Oil Pollution, 8 ILM (1969) at 679 (in force 1980); Offshore Pollution Liability Agreement (OPOL) (1974) ILM at 1409; 1971 Convention on the Establishment of an International Fund for Oil Pollution Damage, 95 UKTS Cmnd 7383 (in force 16 October 1978); see also Vienna Convention on Civil Liability for Nuclear Damage, n. 24 above; (1963) 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy Paris, n. 24 above; (1961) Protocol to Amend the Vienna Convention on Civil Liability for Nuclear Damage and to Adopt a Convention on Supplementary Funding, Art 2(2), 36 ILM 1454(1997).

(44) B. Cheng, General Principles of International Law as Applied by International Tribunals (Cambridge, 1953) at 233–4.

(45) García Amador, Sixth Report on State Responsibility, n. 20 above at 6; C. Eagleton, The Responsibility of States in International Law (New York, 1928) at 202; Brownlie, State Responsibility, n. 9 above at 224; Gray, n. 20 above at 169, Arangio-Ruiz, Second Report on State Responsibility, ILC, Forty-First Session (1989) UN Doc. A/CN.4/425 at 33; Schachter, n. 28 above at 366.

(46) Cheng, n. 44 above at 236.

(47) For a comprehensive survey of the literature and jurisprudence of international courts, see Arangio-Ruiz, Second Report on State Responsibility, ILC, Forty-First Session (1989) UN Doc. A/CN.4/425 at 27–39; see also ILA, Third Report of the International Committee on Legal Aspects of Long-Distance Air Pollution, 61st Conference (Queensland, 1990) at 294; see also Memorial of the Republic of Hungary, n. 27 above at 251, paras 8.27–8.30; Counter-memorial of the Slovak Republic, n. 39 above at 364, para 12.25.

(48) Arangio-Ruiz, Second Report on State Responsibility, YBILC (1989) Vol. II, Part I at 13.

(49) Brownlie, State Responsibility, n. 9 above at 224, referring to the Dix Case, IX RIAA at 121.

(50) B. Graefrath, ‘Responsibility and Damages Caused: Relationship Between Responsibility and Damages’ (1984–11) 185 Recueil des Cours at 95.

(51) See 7 T.A.M at 23–8, in Cheng, n. 44 above at 248.

(52) VII RIAA at 29–30.

(53) F. V. García Amador, Second Report on State Responsibility, (1957) YBILC Vol II document A/CN 4/106 at 6; Arangio-Ruiz, Second Report on State Responsibility, n. 48 above at 13; Cheng, n. 44 above at 253.

(54) See Canadian Claim for Damage Caused by the Soviet Cosmos 954, n. 36 above at 907.

(55) II RIAA at 1032–3.

(56) Germany v. Great Britain and USA, IX RIAA at 15.

(57) War Risk Insurance Premium Claims Case VII RIAA at 29–30.

(58) See the Portuguese Colony (Angola Case), Award I (1928) II RIAA at 1011–31; Cheng, n. 44 above at 242; Gárcia Amador, Second Report on State Responsibility, n. 53 above at 6; Arangio-Ruiz, Second Report on State Responsibility, n. 48 above at 14.

(59) n. 7 above.

(60) n. 36 above.

(61) n. 36 at 907.

(62) Memorial of the Republic of Hungary, n. 44 above.

(63) n. 7 above at 1908.

(64) n. 7 above at 1918.

(65) n. 7 above at 1915.

(66) n. 7 above at 1922–3.

(67) n. 7 above at 1925.

(68) n. 7 above at 1931; see also ALI, Third Restatement, n. 20 above. Comment (d) at 105–6.

(69) It is generally accepted that international tribunals are less concerned with the strict application of the rules of evidence, Gray, n. 20 above at 19; ILA, Third Report on Legal Aspects of Long-Distance Air-Pollution, n. 47 above at 293.

(70) (1931), 282 U.S. 555.

(71) n. 7 above at 1920.

(72) For an extensive review of the cases and the literature, see Arangio-Ruiz, Second Report on State Responsibility, n. 47 above at 13–14.

(73) See generally the discussion in Chapter 1; Brownlie, ‘A Survey of Customary Law Rules for the Protection of the Environment’, in Teclaff and Utton (eds.), International Protection of the Environment (New York, 1974) at 1–4; ILA, Committee on Legal Aspects of Long-Distance Air Pollution, Third Report, n. 47 above at 283 and 296–7.

(74) See the Report of the UNSCEAR, UN GAOR, 37th Session, Supp. No. 45(A/37/45) (1982), and UNGAOR, 41st Session, Suppl. No. 16(A/41/16), (1986); see also UNSCEAR, 43 UNGAOR Supp. (No. 45) UN Doc. A/43/45, (1988); Pelzer 39 NLB (1987) at 66. See generally the discussion in Chapter 1 at 17–18.

(75) See ILA (1986), Interim Report of the Committee on Legal Problems of Continuous and Instantaneous Long-Distance Air Pollution at 207, 62nd Conference.

(76) Arangio-Ruiz, Second Report on State Responsibility (1989) ILC Forty-First Session, n. 47 above at 37.

(77) Fleming, The Law of Torts, 4th edn. (London, 1971) at 632; Winfield and Jolowicz on Tort (London, 1973, 11th edn., ed. W. V. H. Rogers) at 581; Lawson and Markesinis, Tortious Liability for Unintentional Harm in the Common Law and Civil Law (London, 1978), Vol. I at 126 and 129–30; Prosser, Fleming, The Law of Torts, 4th edn. (London, 1971) at 632The Law of Torts, 4th edn. (London, 1971).

(78) The scarcity is noted by Brownlie, Principles, n. 1 above at 456–7; see also State Responsibility, n. 9 above at 189–92; see also ILA, Third Report on Legal Aspects of Long-Distance Air Pollution, n. 47 above at 297; C. Chinkin, Third Parties in International Law (Oxford, 1993) at 208.

(79) Arangio-Ruiz, Second Report on Responsibility (1989), n. 48 above at 15.

(80) Schachter, n. 28 above at 380.

(81) EMEP/MSC-W Reportl/84; EMEP/MSC-W Report 1/88 estimates of Airborne Transboundary Transport of Sulphur and Nitrogen Over Europe, Oslo, August 1988; EMEP/MSC-W Report 1/89, Detection of Sulphur Emissions in Europe During the Period 1979–1986, Oslo, July 1989.

(82) Gray, n. 20 above at 210; K. B. Hoffman, in ‘State Responsibility in International Law and Transboundary Pollution Injuries’, 25 ICLQ (1976) at 509; R. Bilder, ‘The Settlement of International Environmental Disputes’ (University of Wisconsin Sea Grant College Program), Technical Report 231, 58–9.

(83) Wellburn, Air Pollution and Climate Change, 2nd edn. (London, 1994), chs. 2 and 10; see also UNECE, ‘The State of Transboundary Air Pollution’ (Air Pollution Studies) No. 6 (1989) at 23.

(84) UNECE, Assessment of Long-Range Transboundary Air-Pollution (Air Pollution Studies), No. 7 (New York, 1991) at 39–40.

(85) In the literature the problem is considered for the first time by the ILA, in its Third Report on the Legal Aspects of Long-Distance Air Pollution, n. 47 above at 293–7.

(86) ILA, Legal Aspects of Long-Distance Air Pollution (Seoul, 1986), Report at 207.

(87) n. 86 above.

(88) Trail Smelter Case, n. 7 above at 1920.

(89) But see Sandifer, Evidence Before International Tribunals (Charlottesville, 1975).

(90) See, Tunc (ed.), International Encyclopedia of Comparative Law, Vol. XI Torts (Amsterdam, 1986) at 68–70.

(91) McGhee v. National Coal Board (1972) 3 All ER at 1008; Bonnington Castings Ltd v. Wardlaw, [1965] AC, 613; Nicholson v. Atlas Foundry & Engineering Co. Ltd [1957] 1 ALL ER at 776.

(92) (1972) 3 ALL ER at 1010.

(93) Medical evidence was unable to estimate the relative probable contribution of the various sources of risk. For a comprehensive discussion, see J. Stapleton, Disease and the Compensation Debate (Oxford, 1986) at 46.

(94) Per Lord Wilberforce in McGhee v. National Coal Board (1972), 3 All ER at 1008.

(95) See A. T. Szasz, in D. Magraw (ed.), International Law and Pollution (Philadelphia, 1991) at 175 and 177–8; see also the US Radiation Exposed Veterans Act of 1988, 38 U.S.C. 312 (C).

(96) Stapleton, n. 93 above at 46.

(97) ALI, Restatement of Torts, n. 20 above at 431, 432, 465.

(98) See Tunc (ed.), International Encyclopedia of Comparative Law, Vol. XI (Torts) at 68–70; Johnson and Johnson v. Dundas (1945) Ont. Report 670, 4 DLR 624 (H.C.).

(99) ILA, Committee of Legal Aspects of Transfrontier Pollution, Third Report, n. 49 above at 297.

(100) n. 81 above.

(101) Brownlie, ‘A Survey of International Customary Rules of Environmental Protection’, n. 73 at 4–5.

(102) (1978) Vol. I, ICJ Pleadings, n. 30 above at 500.

(103) n. 30 above at 520.

(104) UKAEA, The Chernobyl Accident and its Consequences (London, 1987).

(105) n. 74 above.

(106) See Argument of Senator Murphy, n. 30 above at 177.

(107) Memorial of the Republic of Hungary, n. 27 above at 252.

(108) Counter-memorial of the Republic of Hungary, 5. 12. 1994, Vol. 1 at 266.

(109) H. McGregor, The Law of Damages (London, 1972) at 203.

(110) See Article 38(1)C of the ICJ Statute; international tribunals have invariably awarded damages on the basis of prospective loss, see Whiteman, Damages, Vol. Ill, n. 20 above at 1836; see also Eagleton, The Responsibility of States, n. 45 above at 192.

(111) For discussion in the literature, see Boyle, n. 41 above at 296; Gray, n. 20 above at 88; Handl, ‘Transboundary Nuclear Accidents: the Post-Chernobyl Multilateral Legislature’, 15 ELQ (1988) at 203 and 242–3.

(112) n. 36 above, para 8.

(113) n. 36 above at 906.

(114) See Regulation (EEC) No. 1388/86, OJ No. L 127, 13.5 (1986) at 1; Council Regulation (EEC) No. 1707/87, OJ No. L 146, 31.5 (1986) at 88; Council Regulation (EEC) No. 3020/86, OJ No. L 280, 1. 10 (1986) at 79; Council Regulation (EEC) No. 624/87, OJ No. L 58, 28.2 (1987) at 101.

(115) For payments by the German Government, see Bundesanzeiger of 12 June (1986), No. 105 at 7237 and Bundesanzeiger of 2 August (1986), No. 140 at 10388. The United Kingdom acting under the Food and Environmental Protection Act (1985) issued orders restricting the sale of lamb and vegetables in affected areas. See, for instance, the Food Protection (Emergency Prohibitions) England Order, 1986, SI 1986 No. 1411, cited in P. Sand, Chernobyl Law and Communication (Cambridge, 1998) at 17.

(116) Soviet Union, Proposed Programme for Establishing an International Regime for the Safe Development of Nuclear Energy, Sept. (1986), IAEA Doc. GC (SPL/8). For extended discussion, see Chapter 4 at 118–24.

(117) Scientific opinion supports intervention in the public interest, see ICRP, Protection of the Public in the Event of Major Radiation Accidents: Principles for Planning, 14 Annals of the ICRP No. 2 at 2 (1984) (ICRP Pub. 40).

(118) n. 7 above at 1959.

(119) Whiteman, Damages, Vol. Ill, n. 20 at 2006 9.

(121) Ibid, at 2011.

(122) whiteman, Damages, Vol. Ill, n. 20 above at 2006.

(123) Whiteman, Damages, Vol. Ill, n. 20 above at 2010; García Amador, n. 20 above at 42.

(124) Boyle, n. 41 above at 296; Gray, n. 20 above at 88; Gray, n. 20 above at 90.

(125) 973 UNTS at 3; see also the Tankers Owners' Voluntary Agreement on Liability for Oil Pollution, n. 43 above and the offshore Liability Agreement (OPOL) n. 43 above; Article 8 of the 1988 Convention for the Regulation of the Antarctic Mineral Resources, 27 ILM (1988) at 868.

(126) n. 43 above Article 2(IV) and 2(VI).

(127) See McGregor, n. 9 above; Fleming, n. 77 above at 214; Winfield and Jolowicz on Tort, n. 77 above at 599.

(128) McGregor, n. 9 above at 204–5; see also British Westinghouse Co. v. Underground Railway [1912] A.C. at 673 at 689.

(129) Article 38 (1) C of the Courts’ Statute.

(130) Brownlie, State Responsibility, n. 9 above at 225; Boyle, n. 41 above at 276–7; Boyle, n. 41 above at 296; Gray, n. 20 above at 88; Gray, n. 20 above at 90; Handl, n. 111 above at 202 and 2434; Graefrath, n. 50 above at 97–8.

(131) Whiteman, Damages, Vol. Ill, n. 123 above at 2006–9.

(132) García Amador, Sixth Report on State Responsibility, n. 20 above at 42; see also Orrego Vicuna, in Brown Weiss (ed.), n. 27 above; Barboza, Sixth Report on Liability for Injurious Consequences of Acts not Prohibited by International Law, draft Article 24, YBILC (1990) Vol. II (Part I) at 83.

(133) For instance, the maximum contamination values for the presence of iodine-131 milk were as follows: the United Kingdom and Sweden adopted a value of 2,000 becquerels, the limit adopted in Poland was 1,000, 500 in Hungary, 370 in Austria, and in the German state of Hesse the limit was set at 20. See record of the First Preliminary Meeting, IAEA Doc. GC (SPL.I/OR.l) at 23–56.

(134) FAO, Report of the Expert Committee on Recommended Limits for Radionuclide Contamination of Foods (Rome, 1987).

(135) Articles 43 and 44; Smith, n. 26 above at 46–7.

(136) Of the general texts only the following advert to the problem under discussion: Brownlie, Principles, n. 1 above at 457–9 and State Responsibility, n. 9 above at 189; C. Chinkin, n. 78 above at 15; Schachter, n. 28 above at 381. The problem has received some attention in the more recent literature on environmental damage, see J. G. Lammers, Pollution of International Watercourses (Dordrecht, 1984) at 603–61; Smith, n. 26 above at 44; Barboza, Sixth Report on International Liability for Injurious Consequences of Acts not Prohibited by International Law, YBILC (1990) Vol. II, draft Article 25; ALI, Third Restatement, n. 20 above, S601 Comment (d) at 105.

(137) Libya-Malta Case, ICJ Reports (1984) at 25 at para 40; see also, Nicaragua Case, ICJ Reports (1984) at 431, para 88; Land, Island, and Maritime Frontier Dispute, ICJ Reports (1990) at 135; Nauru Case (Preliminary Objections) ICJ Reports (1992) at 260.

(138) Chinkin, n. 78 above at 199; Monetary Gold Case, ICJ Reports (1954) at 19–32.

(139) Nauru Case, n. 137 above at 258–9; Text of the Trusteeship Agreement is to be found in 10 UNTS (1947) at 3.

(140) In the Nicaragua Case, the Court observed that it lacked the power to direct that a third party be made a party to proceedings, n. 137 above at 392–431.

(141) Nauru Case, n. 137 above at 225.

(142) n. 137 at 258–9.

(143) See 32 ILM (1993) at 1471.

(144) Tunc (ed.), n. 90 above Vol. XI at 73; Lawson and Markesinis, n. 77 above, Vol. 1,126 and 129–30; Fleming, n. 77 above at 632; Winfield and Jolowicz, above at 581.

(145) See, for example, the United Kingdom Civil Liability Contribution Act of 1978; Law Married Women Tortfeasors Act (1935), Art. 6(2); Switzerland, CC Art. 51 and 145; Italy CC Art. 2055 para 2; Poland CC Art. 441 para 2; for a similar right under French law, see the cases discussed by Lawson and Markesinis, n. 77 above at 131; Tunc (ed.), International Encyclopaedia, n. 90 above Vol. IX (ch. 12 Complex Liabilities) at 63–77.

(146) See Winfield and Jolowicz, n. 77 at 585; Lawson and Markesinis, n. 77 above at 132–3.

(147) 4 95 F.2D 213 (Sixth Circuit, 1974).

(148) See Brownlie, State Responsibility, n. 9 above at 189; Chinkin notes that it may be inappropriate to draw general principles from domestic law, n. 78 above at 209; in the International Tin Council Case, the House of Lords expressed doubt as to the existence of joint and several liability of states in international law (1989) 3 WLR at 969 (Lord Templeman); and in the Nauru Case, Judge Schwebel also observed that municipal law analogies were of little use, n. 137 above at 329–30.

(149) Monetary Gold Case, n. 138 above.

(150) In the International Tin Council Case, Lord Templeman observed that ‘an international or domestic law which imposed and enforced joint and several liability on states without imposing and enforcing contribution between those states would be devoid of logic and justice’, n. 145 above 969–84.

(151) 127 F Supp. 553, (1955); 22 ILR (1955) at 985.

(152) n. 151 above at 986.

(153) 1949 jcj Reports; Brownlie, State Responsibility, n. 9 above at 189; however, in the Nauru Case, Judge Schwebel distinguished the case on the ground that the third party in the case was unnamed and unidentified before the Court, and therefore presumably did not deserve any judicial protection, n. 137 above at 330.

(154) Smith, n. 26 above at 55.

(155) 1949 ICJ Reports, 78 at 92.

(156) n. 137 above; Libya-Malta Case, n. 13 above at 25; see also Land, Island and Maritime Frontier Dispute, n. 13 above at 134.

(157) n. 137 above at 258.

(158) n. 137 above at 262.

(159) See, for instance, Schwebel, n. 137 above at 329–30; and Judge Ago observed that to require Australia to shoulder in full responsibility for damage due to Nauru would be extremely questionable at 326–8; only Judge Shahabudeen was inclined to recognize the existence of joint and several liability on the international plane. He concluded that on the facts the responsibility of the three governments was joint and several with the result that Australia could be sued alone, above at 271–83.

(160) Eagleton, n. 45 above at 203; Gray, n. 20 above at 23; see also Arangio-Ruiz, Second Report on State Responsibility, ILC Report of the Forty-First Session, UN Doc. A/CN.4/425 at 34–9; ILA, Committee on Legal Aspects of Long-Distance Air Pollution, Third Report, n. 47 above at 299–300.

(161) Eagleton, n. 45 above at 203.

(162) Gray, n. 20 above at 23.

(163) Schachter, n. 28 above at 381.

(164) n. 20 above at Section 601 Comment (d) at 106.

(165) Barboza, Sixth Report, draft Article 25, YBILC (1990), Vol. II (Part II).

(166) See, for instance, the contributions by Bargesov and Mahiou, Summary Records of the Meetings of the 42nd Session, YBILC (1990), Vol. I at 275 and 276, respectively.

(167) n. 138 above.

(168) See dissenting opinion of Judge Jennings in the Nauru Case, n. 137 above 301–2; and Judge Schwebel, n. 137 above 229–342.

(169) Schachter, n. 28 above at 381.

(170) Convention on International Liability for Damage Caused by Space Objects, n. 22 above.