Amongst the many legal issues arising from the ICJ advisory proceedings in Obligations of States in respect of Climate Change, the erga omnes nature of the obligations involved has a particular significance. This nature comprises not only strictly environmental obligations, but also human rights obligations related to climate change.
The issue presents a singular opportunity to clarify the erga omnes character of certain obligations that do not (necessarily) arise from peremptory norms. In its 2022 Draft Conclusions on Jus cogens, the ILC recalled that not all obligations erga omnes arise from peremptory norms: “For example, certain rules relating to common spaces, in particular common heritage regimes, may produce erga omnes obligations independent of whether they have peremptory status” (Draft Conclusion 17, commentary, para. 3).
The issue is less clear regarding human rights obligations. Are all human rights obligations erga omnes, even those that do not arise from jus cogens? In its seminal dictum in Barcelona Traction, the ICJ included among the sources of the obligations erga omnes, “the principles and rules concerning the basic rights of the human person, including protection from slavery and racial discrimination” (para. 34). The Court also considered that respect for the right to self-determination (characterized as a fundamental human right) is an obligation erga omnes (Chagos Advisory Opinion, para. 154 and 180). However, the right to self-determination, and the prohibitions of slavery and racial discrimination are peremptory norms. So, what happens with other rules of human rights? Regarding Article 2 ICCPR, the Human Rights Committee considered in its General Comment 31, that, “every State party has a legal interest in the performance by every other State party of its obligations. This follows from the fact that the ‘rules concerning the basic rights of the human person’ are erga omnes obligations and that, as indicated in the fourth preambular paragraph of the Covenant, there is a United Nations Charter obligation to promote universal respect for, and observance of, human rights and fundamental freedoms” (para. 2). Quoting Barcelona Traction without mentioning the source, the Committee seems to recognize the erga omnes –actually, erga omnes partes, since it refers only to State parties in the Covenant– character of the obligations under Article 2 ICCPR –and arguably, the obligation under Articles 55(c) and 56 of the UN Charter–. The Inter-American Court of Human Rights has adopted a similar view regarding the obligations under the Inter-American Convention (see, i.a. Advisory Opinion OC-26/20, para. 69 and 164). Have those obligations also an erga omnes nature under international law?
A number of participants in the advisory proceedings expressed their views on this topic– both in their written statements (WS) and comments (WC), and in their oral presentations – Therefore, the purpose of this contribution is to offer a preliminary survey of those positions, regarding the erga omnes nature of human rights obligations and the consequences of their breach in international law.
Erga omnes nature of human rights obligations
(1) Customary human rights obligations as erga omnes
Several participants quoted the dictum in Barcelona Traction. In doing so, the Melanesian Spearhead Group (MSG) submitted “that State customary human rights obligations are held erga omnes and apply extraterritorially. This interpretation is supported by the fact that the UDHR guarantees the fundamental human rights of “all human beings” and imposes no territorial restriction on State obligations to respect, protect, or fulfil them” (Melanesian Spearhead Group, WS, para. 257).
Those participants drew a link between the customary human rights obligations and their erga omnes nature, although they did not specify exactly which human rights obligations have this nature. They did stress, however, the customary character of the rights enshrined in the Universal Declaration (Melanesian Spearhead Group, WC, para. 88; Costa Rica, WS, para. 65 and 128; Vanuatu, WS, para. 250; Sierra Leone, WC, para. 3.26; Ghana, WC, para. 3.33). The European Union considered that the provisions of the UDHR, the ICCPR, and the ICESCR “are generally accepted as reflecting customary international law” (EU, WS, para. 223; see also para. 277). Vanuatu explained:
“This Court has itself recognized the “fundamental principles enunciated in the [UDHR]” as a source of legal obligations, consistent with the understanding that substantive obligations can be derived from general principles. Moreover, the Court has confirmed that the obligations arising from basic human rights have an erga omnes character” (Vanuatu, WS, para. 251).
Other participants emphasized the erga omnes character of the obligation to refrain from large-scale violations of human rights, prohibited by peremptory norms (Vanuatu, WS, para. 563; Cook Islands, WC, para. 85; Dominica, CR 2024/38, p. 56). In that vein, Cameroon held:
“Violations of obligations related to the environment often follow a series of actions and omissions that constitute a serious breach of obligations erga omnes, such as ecocide or human rights violations” (Cameroon, WC, para. 101).
More succinctly, Kiribati considered that the rights and duties of States with respect to climate change “are grounded in foundational, erga omnes principles of international law”, included the protection of basic human rights (Kiribati, WC, para. 52).
(2) Conventional human rights obligations as erga omnes partes
Antigua and Barbuda seems to follow a different approach. It discusses a series of states obligations in respect of climate change, including the obligations under international human rights law to respect, to protect and to fulfil human rights (Antigua and Barbuda, WS, para. 171-197), and considers that obligations under human rights treaties are of an erga omnes partes character (Ibid., para. 571). Although it considered other erga omnes obligations under customary international law (for example, the prevention of harm to the environment), it did not mention human rights obligations with that character, stressing only obligations under human rights treaties. It seems, therefore, that it recognizes only conventional human rights obligations –with an erga omnes partes nature–, but not customary obligations.
Also under conventional human rights law, Samoa quoted the Human Rights Committee GC 31 and concluded: “In respect of obligations erga omnes States Parties to the ICCPR have a legal interest in the protection and promotion of fundamental human rights” (Samoa, WC, para. 158). If its reasoning is limited to States Parties to the Covenant, the obligations have an erga omnes partes nature.
(3) Erga omnes character of specific human rights obligations
Regarding specific rights, a great number of participants stressed the erga omnes character of the right to self-determination and the duties to respect and ensure it (Melanesian Spearhead Group, WS, para. 234 and 245; Bahamas, WS, para. 154; Mauritius, WS, para. 167; Bangladesh, WS, para. 121; Vanuatu, WS, para. 289; Madagascar, WS, para. 59; Albania, WS, para. 96; Cameroon, WC, para. 66; Fiji, CR 2024/40, p. 74; Sierra Leone, WS, para. 3.99; Solomon Islands, WS, para. 171; Kiribati, WS, para. 151; Kenya, WS, para. 5.66; Liechtenstein, WS, para. 28; AU, WC, para. 119; Micronesia, CR 2024/45, p. 26; Namibia, CR 2024/45, p. 43; Dominican Republic, WS, para. 4.44; Saint Vincent and the Grenadines, WS, para. 109; The Gambia, WC, para. 4.11; Samoa, WC, para. 57; Timor-Leste, WS, para. 335; Tuvalu, WS, para. 148; Papua New Guinea, CR 2024/43, p. 27; EU, WS, para. 223; OACPS, WS, para. 66; COSIS, WS, para. 67 and 74).
Some of the participants considered that the right to life is protected under customary international law and creates obligations erga omnes (Vanuatu, WS, para. 343; Egypt, WS, para. 335; Samoa, WC, para. 73; COSIS, WS, para. 160). Some of them even affirmed that the duty to respect the right to life is a peremptory norm (Sierra Leone, WC, para. 3.26; The Gambia, WC, para. 5.14).
Other participants recalled that the prohibition of racial discrimination generates erga omnes obligations (Cook Islands, WC, para. 124.c; OACPS, WS, para. 82).
Invoking Barcelona Traction, Slovenia affirmed that “As a fundamental human right and as a necessary part of human rights legal framework, the obligations owed by States in order to implement the right to a clean, healthy and sustainable environment are obligations erga omnes, owed to the internationally community as a whole. This is further confirmed by their very nature, object and purpose: the protection of the environment and the climate system for all humankind” (Slovenia, WS, para. 36). Barbados, also quoting Barcelona Traction, stressed the link between a healthy environment and the enjoyment of human rights (Barbados, WS, para. 160-162). It considered that the obligation to protect the environment “is also erga omnes and erga omnes partes by virtue of its direct link with fundamental human rights obligations” (Ibid., para. 174).
(4) Dissenting viewpoints
Only the United States held an opposite view on this topic:
“Some States have asserted the erga omnes character of various international human rights law obligations. As the United States has observed, the question of which human rights give rise to erga omnes obligations is not settled under international law. […], there is no well-established method or set of criteria for ascertaining which rights might generate erga omnes obligations. While the United States remains in full agreement that States have a profound and shared interest in the protection and promotion of human rights worldwide, it does not follow that all international human rights law obligations have an erga omnes character” (US, WC, note 172).
Although it is not a clear rejection of the idea, the US did not suggest examples of human rights obligations with an erga omnes character, nor propose a method or criteria for ascertaining them (it only reaffirmed the same position expressed 20 years ago in its observations to GC 31). Regarding the right to self-determination –which in its view is not at issue in the proceedings–, it merely acknowledged that the ICJ recognized the obligation to respect the right to self-determination having an erga omnes character (US, WC, para. 4.64), but it questions whether the right constitutes a jus cogens norm (Ibid., note 196).
Consequences of breaches of obligations erga omnes
Several of the aforementioned participants also expressed their positions on the consequences of breaches of obligations erga omnes.
Amongst those consequences is, of course, that any State can invoke responsibility for violations of obligations erga omnes (Bahamas, WS, para. 249; COSIS, WS, para. 159; Kenya, WS, para. 6.117, quoting Barcelona Traction).
However, other participants, stressed that “a special régime of responsibility applies to breaches of the obligation not to cause significant harm to the climate system and the obligation to respect human rights, including the rights of peoples, which are peremptory rules of international law that give rise to erga omnes obligations” (Burkina Faso, WS, para. 338), and that:
“violations to human rights and the obligations arising from the right to self-determination have particular consequences when attached to serious breaches (e.g., largescale ecocide and human rights abuses) that are owed erga omnes or to the international community as a whole” (Kiribati, WC, para. 74).
For such serious breaches, the MSG emphasized, “the customary rules codified in ARSIWA provide for an aggravated regime of State responsibility entailing additional legal consequences” (Melanesian Spearhead Group, WS, para. 323; see also OACPS, WS, para. 190-191).
It seems that these participants assign to breaches of obligations erga omnes, the same consequences provided for serious breaches of peremptory norms in Article 41 ARSIWA. This is not new, since the ICJ itself has done the same in its case law, more recently, in the 2024 Advisory Opinion on the Occupied Palestinian Territory, where it directly mentioned “the serious breaches of obligations erga omnes” (para. 280).
Therefore, some of the participants considered that three obligations arise for other States from a breach of an obligation erga omnes:
“the obligation not to recognize the illegal situation resulting from the violative conduct, not to render aid or assistance to the breaching State or States in maintaining the illegal situation, and to cooperate to put an end to the breach” (Vanuatu, WS, para. 602; see Cook Islands, WC, para.125 and 136; see also OACPS, WS, para. 194).
Final remarks
Out of 107 participants in the proceedings, 36 –one third– explicitly affirmed the erga omnes nature of human rights obligations under international law. These participants form part of a great majority –from all regions of the world– that supports the application of human rights obligations in the context of climate change and their importance in the advisory proceedings. The General Assembly itself, in its request for an advisory opinion, asked the ICJ to have particular regard to the UN Charter, the ICCPR, the ICESCR and the rights recognized in the UDHR (A/RES/77/276). Just one state (the United States) criticized this approach, by considering that the framework of international human rights law is not well-suited to address climate change and questioning the erga omnes nature of human rights obligations.
Therefore, the weight a great number of participants gave to obligations erga omnes, especially in the field of human rights, gives the Court little room to evade a pronouncement on the issue, mainly when most of them invoked Barcelona Traction and other judgments of the Court.
The advisory opinion gives a great opportunity to the ICJ to clarify issues such as the identification of those human rights obligations that have an erga omnes character (particularly those arising from peremptory norms), their relationship with obligations erga omnes partes arising from human rights treaties, and the consequences of their violation (and their relationship with serious breaches of peremptory norms, as well).
The last word on these important issues, of course, belongs to the Court, but the participants have offered a significant amount of material for the task.
