The international climate change regime and general principles of law

The relationship between general principles of international law and Article 38(1) of the ICJ statute: A law of the sea perspective

Introduction. Taking into account the fact that neither the normative nor the doctrinal form contains an exhaustive list of principles of international law, clarification of the issues of their concept and content problems is important not only for international law itself and its adequate understanding, but also for application of law at the national level, because the national legal systems of states, including the Russian Federation, are widely based on the principles of international law. This article deals with theoretical and practical issues related to the principles of international law, and the study is not limited to the framework of international law, but also covers other general theoretical aspects of law, as well as non-normative aspects. The article contains the main thesis of the speech of prof. Aslan Abashidze addressed the judges of the Supreme Court of the Russian Federation, held at the invitation of the guidance of the Supreme Court of the Russian Federation on November 23, 2017. Materials and methods. The study is based on a considerable amount of materials, including international legal acts, decisions of international judicial institutions, national legislation of the Russian Federation and decisions of the highest judicial bodies of the Russian Federation, as well as classical and contemporary doctrinal studies of Russian and foreign authors. The methodological basis of the research was the general scientific methods (logical and system analysis, the dialectical method, methods of deduction and induction) and special methods of cognition (historical and legal, comparative legal and formal legal methods, method of legal modeling and forecasting). Research results. On the basis of the study of the doctrinal positions of Russian and foreign authors, international legal acts and practice of international judicial institutions, as well as national legislation of the Russian Federation and the national court practice of the Russian Federation concerning the principles of international law, the author makes conclusions on the conceptual and substantive problems concerning the principles of international law. Discussion and conclusions. In the article the author analyzes various approaches to the content of such notions as “general principles of international law”, “generally recognized principles of international law”, “basic principles of international law”, “fundamental principles of international law”, “imperative norms of international law”. The author comes to the conclusion that “generally recognized principles of international law” both in the western and in the Russian doctrine of international law presuppose “general principles of international law” or “general principles of law” as a whole with the addition of “civilized nations”, which are often referred to as “fundamental”; these principles include, first of all, the principles enshrined in the UN Charter, the 1970 Declaration on the Principles of International Law and the 1975 Helsinki Final Act of the CSCE. The analysis of practice of international judicial institutions, mainly the International Court of Justice, allows to conclude that the Court does not differentiate the principles which it applies; all of them, as enshrined in the UN Charter, i.e. “generally recognized”, and others (in particular, principles of branches of international law, for example, the principle of humanism) are referred to as “general” principles of law. Moreover, the general principles of law, according to legal doctrine, may cover moral norms, which have been fragmentarily and declaratively already found fixation in international documents, and which in the long term may strengthen their international legal status up to an imperative norm.

In this paper, the author advocates for the recognition of the principle of ‘non-cruelty to animals’ as a General Principle of Law under Article 38(1)(c) of the Statute of the International Court of Justice (ICJ). This principle of ‘non-cruelty to animals’, commonly understood as condemning the unnecessary infliction of suffering on animals, is widely reflected in national legal frameworks, indicating a broad global consensus against cruelty. However, the term ‘unnecessary’ is often applied inconsistently and is open to variable interpretation across jurisdictions. The author therefore proposes interpreting the principle through the lens of avoidability, suggesting a clearer, and in our view more objective standard that suffering should be avoided wherever possible. This reframing would promote a more objective and actionable standard, address subjective exemptions and eliminate activities that cause avoidable suffering to animals, while promoting viable alternatives to animal products and animal-based methods. The author also examines how current anti-cruelty laws are limited, often excluding certain animal groups or exempting practices for traditional, scientific, or economic purposes. By recognizing non-cruelty as a General Principle of Law, the ICJ could officially establish the international value of this principle, ensuring that animal laws consistently reflect a consensual baseline for ethically treating sentient beings. Such recognition would establish non-cruelty as a foundation for new international frameworks, specifically avoiding animal crimes, and would encourage the development of global instruments that universally condemn and prevent animal cruelty. This proposed legal framework would represent a significant advancement in both ethical and legal treatment of animals, affirming a new international commitment to the legal protection of animals as sentient beings.

Since the term “general principles of law recognized by civilized nations” appeared in the Statute of the Permanent Court of International Justice in 1920, there has been ongoing debate in legal doctrine regarding its meaning, how it is formed, identified, and its scope of application. The abundance of literature devoted to general principles of law speaks more to the diversity of existing opinions than to the existence of an established consensus on these issues, including the question of the existence of general principles of law with a limited territorial scope of application (“regional general principles of law”) and their role in contemporary international law. Unfortunately, the approach of the UN International Law Commission, reflected in the Draft Conclusions on General Principles of Law 2025, does not provide a clear answer to the question of the existence of regional general principles of law, although it does not exclude the possibility of their emergence. At the same time, recognition at the universal level of the existence of regional general principles of law (the most striking examples of which are the general principles of European Union law and the formation by the EAEU Court of the principles of EAEU law) may have a direct practical and, moreover, positive effect for the Commission itself, comparable to the recognition by the Commission several years ago of local international customs. Regional general principles of law may be applicable to disputes having regional significance in jurisdictions with both universal and regional coverage. Furthermore, they can be used to fill gaps in regional international treaties, as well as for the purposes of their interpretation. The process of establishing the regional general principles may differ from the order applicable to universal general principles of law, since courts or states insisting on their existence and application must first prove their local specific character. All this shows that despite the Commission’s obvious intention to fully support a universal approach in international law, it would be counterproductive for the Commission’s authority not to notice the reality emerging at the regional level in terms of regional principles, particularly in terms of recognition by states, as well as national and international courts, of the results of the Commission’s work on general principles of law.

This Preface to the EPL Special Issue 55 (6) 2025 on the Advisory Opinions (2024-2025) of the International Courts and Tribunals (ICTs) onClimate Change seeks to provide an overview and serves as a lead research article to introduce the legal trajectory adopted for seeking an authoritative view on the “obligations of the States” under international law and “legal consequences under these obligations for States” (worded differently before each ICT) in relation to climate change from the three ICTs. The three marathon processes for seeking Advisory Opinions (AOs) took place before the International Court of Justice (ICJ), Inter-American Court of Human Rights (IACtHR) and International Tribunal on the Law of the Sea (ITLOS). The fourth one is pending (since May 02, 2025) before the African Court of Human & Peoples’ Rights. The respective ‘requests’ were presented to these ICTs on May 29, 2023 (ICJ), January 9, 2023 (IACtHR) and December 12, 2022 (ITLOS). After going through their procedural craft of formal requests, written statements, oral presentations and specially arranged meetings (by the ICJ) with some stakeholders such as Intergovernmental Panel on Climate Change (IPCC), the three ICTs delivered their respective AOs on July 23, 2025 (ICJ, The Hague), July 03, 2025 (IACtHR, San Jose) and May 21, 2024 (ITLOS, Hamburg). Thus, the AOs of these three ICTs provide a unique legal corpus ostensibly for strengthening legal basis of the State-centric consensual regime (1992 UNFCCC, 1997 Kyoto Protocol and 2015 Paris Agreement) on climate change. These AOs have brought to the fore role of the ICTs as ‘sentinels’ even as entire climate change global regulatory process (1992-2025) seem to be floundering after 33 years in spite of grim scientific projections about the “climate emergency”. It is in this backdrop that this preface-cum-research article provides the context, a preliminary overview of the outcomes of the three ICT AOs and possible future trajectory to resolve the “climate conundrum”, beyond the three AOs.

Principles in Modern International Law (Certain Issues of Concept, Nature, Genesis, Substance and Scope)

A PROPOSED DEFINITION OF JUS COGENS CUSTOMARY NORMS The definition of customary international law expounded here, combined with the theory of authoritative norms sketched in Chapter 4, help to illuminate the concept of jus cogens customary norms and their particular content. Here I focus on jus cogens norms that are customary norms. Some commentators have persuasively argued that jus cogens norms can also arise from general principles of law. This is supported by the language of Article 53 of the Vienna Convention on the Law of Treaties, which refers to peremptory norms of “general international law,” a term which, we have seen, in turn includes general principles of law. Moreover, I have elsewhere suggested that general principles of moral law that reflect essential ethical principles should be classified as jus cogens norms. The criteria used to identify jus cogens general principles of law should be similar, but not identical, to those for customary norms, which are explicated in the following pages. I propose that customary norms of jus cogens should be defined as those norms otherwise satisfying the requirements for customary international law suggested in this and earlier chapters that: 1) states generally believe should be strongly peremptory in character because of the importance of the values they promote; 2) states generally believe further such important values that they should bind all states, even states that have persistently objected to them; 3) states generally believe in particular further such important values that they should preempt any contrary provision of an agreement between states and indeed should render such an agreement entirely void, including rendering void provisions in the agreement that do not contravene them; and […]

Climate Change and the International Court of Justice

Permanent Court of International Justice — Statute of — Article 38 — General Principles of Law — “Enrichissement sans cause”.3International Law — Sources of — General Principles of Law — Enrichissement sans cause — Article 38 of the Statute of the Permanent Court of International Justice.

Climate change is a security problem in as much as the kinds of environmental changes that may result pose risks to peace and development. However, responsibilities for the causes of climate change, vulnerability to its effects, and capacity to solve the problem, are not equally distributed between countries, classes and cultures. There is no uniformity in the geopolitics of climate change, and this impedes solutions.

Public international law and comparative law have so far been regarded as largely distinct fields, with little to no overlap between them. The degree of separation between the two disciplines is rendered in particularly stark relief by the absence in practice or scholarship of any real inquiry into the relationship between comparative law on the one hand and customary international law and general principles of international law on the other. Some eminent international lawyers go so far as to claim that it would be both unnecessary and unrealistic to have recourse to comparative law in the context of the identification of customary international law and general principles of law, pointing to the case law of the Permanent Court of International Justice and the International Court of Justice, which, according to them, “show[s] a clear disinclination towards the use of the comparative method.”

One can find in European and international legal literature many inventories or accounts of general principles of law. This is because the phrase ‘general principles of law’ has polysemous meanings and is credited with multiple roles. In this chapter, I do not offer another inventory of general principles of law or discuss the content of particular principles, but examine their role in the constitutional reading of the international and European Union political order. In other words, this chapter is a study of constitutional patterns prescribed by general principles of law. For this reason, I shall first explore typologies of such principles, and then look at how the European and international constitutional culture is defined by them. My attention will then be turned to the forces that vie to organise the international and the EU political space by focusing on the role of the International Court of Justice (ICJ) and the Court of Justice of the European Communities (European Court of Justice; ECJ) in applying or interpreting general principles of law.

This opinion critically analyses the ‘advisory opinion’ of the International Court of Justice (ICJ) which concerns the obligations of States in respect of climate change (2025), and in doing so, identifies issues that remain unresolved with the advisory opinion. This opinion also considers the principle of erga omnes, which is briefly mentioned in the ‘advisory opinion’ and also discusses climate change obligations that have the character of erga omnes , that is, obligations that are owed by a State to members of the international community as a whole. It is suggested that the ICJ has missed opportunities to clarify the relationship between the obligation(s) concerning climate change, the principle of erga omnes , consent and customary international law. It is also argued that the list of obligations that were considered jus cogens by the International Law Commission could be expanded, in the context of climate change, and notes that these types of obligations are also owed to members of the international community as a whole ( erga omnes ).

This chapter presents sources and rules of international law: custom and customary law, general principles of law, and treaties relevant to the study of each of the case and advisory opinions that has been dealt by the International Court of Justice (ICJ). The analysis section covers four patterns of analysis: duration of cases and advisory opinions of the Permanent Court of International Justice (PCIJ) and the ICJ; records of states as applicant(s) and/ or respondent(s); records of states and authorised organisations on written and oral statements; and records of declarations and opinions of judges and judge ad hoc . Keywords: International Court of Justice (ICJ); International Law; Permanent Court of International Justice (PCIJ)

General Principles and the Coherence of International Law provides a collection of intellectually stimulating contributions from leading international lawyers to the discourse on the role of general principles in international law. Offering a comprehensive analysis of the doctrines, practices, and debates on general principles of law, the volume assesses their role in safeguarding the coherence of the international legal system. This important book addresses the relationship between principles of law and the other sources of international law, explores the interplay between principles of law and domestic and regional legal systems and the role of principles of law with regard to three specific regimes of international law: investment law, human rights law and environmental law.