On 29 March 2023, the United Nations General Assembly adopted by consensus a resolution which requested the International Court of Justice to give an Advisory Opinion on the obligation owed by States concerning climate change. This resolution came at the request of Vanuatu, and was first the initiative of law students at the University of the South Pacific who formed the Pacific Islands Students Fighting Climate Change.
As well as requesting the ICJ to consider the obligations of States to ensure the protection of the climate system and the environment, the UNGA Resolution also asks the ICJ to consider the legal consequences for States who have caused climate harm not just to existing States but also to ‘past and future generations’ of people affected by climate change.
This consideration of liability to future generations presents an opportunity for the ICJ, and for States making written statements to the Court, to make use of Article 38(1)(c) of the Court’s Statute and embrace legal pluralism in a deeply meaningful fashion to consider custom and traditional laws and practices of peoples - many of which will be the most impacted by the effects of climate change and rising sea levels.
This concept of owing duties to future generations is not new. Often referred to as inter-generational equity, it is the idea that humans must use resources in a way not only that is fair to those living and relying on them now, but also in a way that is fair to those who will need those resources in the future. It is enshrined in soft law environmental law instruments, such as the Rio Declaration Principle 3. However it has not yet been found to be a general and binding rule of international law. This upcoming Advisory Opinion could change this, and the under-utilised third source of international law might be the best way to achieve this.
Article 38(1)(c) sets out the third source of international law that the ICJ can consider: the ‘general principles of law recognised by civilised nations’. To use this source, one must assess both horizontal and vertical generality of any given legal rule or principle. Horizontal generality requires a rule be found across a wide number of domestic legal systems; vertical generality requires the rule be suitable for abstraction from the domestic to the international legal plane. This horizontal assessment of domestic legal systems has historically been mostly limited to traditional state based systems - and within this, most often to a small cluster of European nations. This led Judge Ammoun to famously lament in 1969 the North Sea Continental Shelfcase that the use of the source was a ‘Concert of Europe’: something that in truth has not changed that much in the subsequent 50 plus years.
However, the source shows potential far greater than its use so far, potential that was harnessed both by Judge Ammoun and later by Vice-President Weeramantry in the Gabcikovo-Nagymaros Project case. It is important to note that the lack of recognition of diverse legal systems and diverse voices in international law is well known and well established. International law can be notoriously bad at giving voice to the marginalised: from the failure of the League of Nations to hear indigenous petitions to it to the failure of Australia, the US, New Zealand and Canada (each with substantive disparity between their own indigenous and non-indigenous populations) to vote in support of the United Nations Declaration on the Rights of Indigenous People in 2007.
This has led to international law being referred to as ‘European’ international law: and although movements including the Third World Approaches to International Law (TWAIL) have challenged this, the Western domination of international law and its structures continues.
How then can General Principles change this? Nowhere in the text of Article 38(1)(c) is the scope of the principle limited to the (traditional) domestic legal systems of States: rather all that is required is that the relevant principles are recognised by ‘civilized’ nations. While many argue that the ‘civilized’ is anachronistic, having no modern meaning, the history of the use of the source suggests this modifier may have actually influenced the restriction of legal systems examined to mostly (white) European ones. To countermand such an approach, a broad reading of Article 38(1)(c) could take it encompass all domestic legal systems in a plural sense, recognising that beyond and beneath State law lies well established indigenous, traditional and/or customary legal systems. To examine these legal systems for horizontal generality would allow us to truly say we are no longer restrained by exclusionary and weaponised concepts of ‘civilization’.
Indeed, this is precisely what Vice-President Weeramantry did in his Separate Opinion in the Gabcikovo-Nagymaros Project when he argued that the source ‘expressly opened a door’ for the import of principles from ‘living law’ into international law. In that case, Weeramantry looked to indigenous legal systems for support of a principle of sustainable development. Non-state legal systems as a basis for a General Principle were also considered by Judge Ammoun in North Sea Continental Shelf, Judge Weeramantry in Greenland and Jan Mayen, Judge Tarazi in the Tehran Hostages case, Judge El-Kosheri in the Aerial Incident at Lockerbie and Judge Al-Khasawneh in the Aerial Incident of 10 August 1999.
On these lines, when considering an argument to found the principle of inter-generational equity as a binding norm of international law, Article 38(1)(c) could be used to look not just at States who have this principle enshrined in their written domestic laws, but also at legal cultures, including indigenous, religious and customary, who have the principle enshrined in their laws. As Edith Weiss writes, ‘the concept of intergenerational fairness in using and conserving the planet strikes deep chords in the major cultural and legal traditions of the world, including the Judeo-Christian, Islamic, African customary law, and Asian nontheistic traditions’. Using Article 38(1)(c) in an expansive and truly global fashion would allow the ICJ and those making statements to it to draw on these traditions to help found a General Principle of inter-generational equity.
To do so could be of particular significance in this Advisory Opinion, spearheaded and led as it has been by Pacific Islands students, communities and States. By examining Pacific customary law (as well as other indigenous and customary legal systems) as a basis for a General Principle on intergenerational equity, Pacific voices and Pacific law could be truly heard well by international law.
Imogen Saunders is Associate Professor at the ANU College of Law and Director of the Centre for International and Public Law. Her book on Article 38(1)(c) of the Statute of the International Court of Justice, in which she argues for a global approach to General Principles, is published with Hart: https://www.bloomsbury.com/au/general-principles-as-a-source-of-international-law-9781509936083/
*The phrase ‘hearing well’ is taken from Sophie Rigney, ‘On Hearing Well and being Well Heard: Indigenous International Law at the League of Nations’ (2021) 2 TWAIL Review 122.
