ICJ Advisory Opinion on Climate Change - AOSIS Oral Submission - Part 2 - Cooperation, Maritime Zones & Statehood

1. Mr. President, Madam Vice President and distinguished members of the Court, it is my profound honour to deliver this submission on behalf of the 39 member states of AOSIS.
2. The remainder of our submission will discuss three key points that are of particular importance to SIDS. Specifically, we respectfully ask this court to: first, affirm that the duty of cooperation is a general principle of international environmental law, including the provision of financial and technological assistance; second, recognize the stability of maritime zones ; and third, affirm that there is a principle of the continuity of statehood in international law.

III. Duty of Cooperation in International Environmental Law

1. The duty of international cooperation is a foundational principle in international law, essential for addressing global challenges. This duty is particularly crucial in the context of climate change, where the effects are global, transboundary and disproportionately and inequitably impact vulnerable States, especially SIDS.
2. The duty of cooperation is enshrined in the United Nations Charter, committing all Member States to "take joint and separate action in cooperation with the Organization for the achievement"[1] of social and economic development. It is also contained in the Universal Declaration of Human Rights and the Declaration on the Principles of International Law Concerning Friendly Relations and Cooperation Among States, as well as being a foundational principle in international human rights and disaster law.
3. This duty is found in multiple international and regional agreements, including human rights instruments, and is supported by significant state practice, including multiple resolutions in the Human Rights Council and General Assembly.
4. We submit that there is a duty to cooperate in international environmental law that is a general principle of international law. The Rio Declaration on Environment and Development (1992) elaborates on this duty in Principle 7, stating: "States shall cooperate in a spirit of global partnership to conserve, protect and restore the health and integrity of the Earth's ecosystem.”[2]
5. This Court has considered this duty extensively, albeit usually in the context of pre-existing bilateral or multilateral agreements and has noted that States must approach international environmental issues in a cooperative manner. As this Court said in the Gabcikovo-Nagymaros judgement: “..in the field of environmental protection, vigilance and prevention are required on account of the often irreversible character of damage to the environment and of the limitations inherent in the very mechanism of reparation of this type of damage”.[3]
6. We also submit that the duty of cooperation is found in relevant treaties. Paris Agreement Article 9, para 1 mandates that "developed country Parties shall provide financial resources to assist developing country Parties with respect to both mitigation and adaptation in continuation of their existing obligations under the Convention."[4]Article 10 establishes a technology framework to promote and facilitate enhanced action on the development and transfer of environmentally sound technologies to developing countries. These provisions reflect the legally binding nature of the duty of cooperation, highlighting the critical role of the provision of means of implementation as a form of cooperation.
7. Recognizing that cooperation is absolutely necessary to solve global environmental problems, we respectfully urge the Court to affirm that the duty of cooperation is a general principle of international environmental law. This will help to ensure that the most vulnerable States, in particular small island developing states, have the resources and support needed to adapt to and mitigate the impacts of climate change.

IV. Stability of Maritime Zones in the Face of Climate Change

1. I will now speak on our second issue, the stability of maritime zones.
2. The need to ensure legal stability, security, certainty and predictability underpin the United Nations Convention on the Law of the Sea (UNCLOS) and customary international law. We submit that once a state has deposited charts or coordinates of maritime zones in accordance with UNCLOS, it is not required to update them. These maritime zones and their associated rights and entitlements shall not be reduced, no matter the physical effects of climate change-related sea level rise.

Legal Framework and Principles

1. UNCLOS provides the legal framework for the establishment of baselines and maritime zones, including territorial seas, Exclusive Economic Zones (EEZs), and continental shelves. It does not require States to revise their maritime baselines due to natural changes, such as erosion or sea-level rise. This silence is significant and reflects the broader principle of stability and predictability in international law. As highlighted by the Pacific Islands Forum (PIF) in its 2019 submission to the ILC, "the absence of an explicit requirement for updating baselines demonstrates an implicit intent to ensure stability and legal certainty…”.[5]

State Practice and Legal Commitments

1. In 2021, the Leaders of the PIF adopted a Declaration on Preserving Maritime Zones in the Face of Climate Change-Related Sea-Level rise, in which they proclaimed that “maritime zones, as established and notified to the Secretary-General of the United Nations in accordance with the Convention, and the rights and entitlements that flow from them, shall continue to apply, without reduction, notwithstanding any physical changes connected to climate change-related sea-level rise.”[6] Later that year, the 39 heads of state and government of AOSIS made a similar Declaration.
2. In addition, there have been numerous similar statements made at the General Assembly, in submissions to the ILC, and in declarations by states upon deposit of geographical coordinates to the Secretary General which have consistently reiterated this interpretation. This includes statement by major coastal states, including the United States and most recently, the United Kingdom. In November, the UK Minister of State for Development delivered a statement in the House of Commons on preserving maritime zones in line with the PIF and AOSIS Declarations. Collectively, this is evidence of broad state practice concerning the stability of maritime zones.
3. In addition to these statements, the overwhelming practice of states in Maritime Zone Notifications since the entry into force of UNCLOS is further evidence of the stability of maritime zones. In the 164 Maritime Zone Notifications filed since 1995, only a single state has revised their baselines because of a change in the baselines. The Other states have provided additional detail or additional basepoints, but none other have been revised.

Consistent with Legal Principles

1. Maintaining the stability of maritime zones is consistent with a number of principles of international law including uti possidetis juris. This principle served during the wave of decolonization in the 20th century to preserve existing boundaries under international law to maintain legal stability and prevent the eruption of conflict. Applying this principle to maritime zones in the context of climate change-related sea-level rise is in the interest of the international community, to ensure legal stability, security, certainty and predictability and reduce the risk of potential conflict.
2. Second, the principle of permanent sovereignty over natural resources also continues to be integral to the economic development of the developing states. This widely recognized principle, affirmed by this Court, reinforces the need to preserve the maritime rights and entitlements of AOSIS members, particularly with respect to their natural resources.
3. Finally, the principle of equity demands the stability of maritime zones. SIDS have contributed negligibly to the causes of climate change, yet they face some of the most severe impacts, including the potential loss of land territory and marine resources. Requiring SIDS to adjust their maritime zones due to sea-level rise would impose an unjust burden, exacerbating existing vulnerabilities and undermining the principles of equity and fairness in international law.

Conclusion

1. We urge the Court to affirm that maritime zones, once established and notified in accordance with UNCLOS, shall remain unchanged, notwithstanding the physical changes connected to climate change-related sea-level rise. Such an affirmation is vital to safeguard the legal entitlements and sovereign rights of SIDS and to uphold the principles of justice and equity that are fundamental to the international legal order.The Court could make this affirmation in its response to paragraph (b) of the question.

V. Continuity of Statehood and Sovereignty Despite Sea-Level Rise

1. Mr. President, distinguished members of the Court, turning to our final issue. The principle of continuity of statehood, as well as sovereignty and United Nations membership, is fundamental to the international legal order. In the context of climate change, this principle holds that statehood once established, endures despite physical changes to or complete inundation of a State’s land territory due to climate change related sea-level rise.
2. SIDS have been clear that there is no existential threat to our statehood from sea-level rise. We must not conflate the physical reality of land territory becoming submerged, with the legal rules concerning statehood and sovereignty, including permanent sovereignty over natural resources.

Historical Precedent

1. The principle of continuity of statehood is well-established in international law. Historical precedents over the past century have illustrated that the continuity of statehood and sovereignty is central to maintaining international stability and upholding the rights of peoples.
2. The Montevideo Convention on the Rights and Duties of States (1933), particularly the four criteria, is sometimes cited in these discussions. However, these criteria were drafted by a limited number of states at a time when the unique challenges posed by anthropogenic climate change were unknown. Most critically though, this historical context taken together with state practice strongly suggests that these criteria are for the establishment of states, not their continuation and certainly not to justify their termination.
3. Continuity of statehood has been the default and upheld in various historial contexts. First, international law has long recognized the legitimacy of governments in exile. During World War II, governments in exile retained their sovereignty and legal status despite the occupation of their territories, maintaining their representation in international organizations.
4. Second, the dissolution and reconstitution of states, such as in the case of federations or unions, further highlight the enduring nature of statehood and sovereignty. States have reasserted their independence after periods of union or merger, and resumed participation in international organizations without delay.
5. In retrospect, it might be argued that each of these situations were temporary, but at the time, that was unclear. The international community continued to respect their statehood, sovereignty and participation in international organizations, despite profound political transformation. Similar considerations must now be applied in the present circumstances.

State Practice and Declarations

1. In addition to earlier state practice and that surveyed by the ILC and ILA, there is an increasing body of practice that reflects a clear commitment of States to preserving statehood and sovereignty despite the physical threats posed by climate change.
2. First, at the national level, multiple SIDS have adopted legal measures to reinforce the continuity of their statehood. For example, a number of Pacific SIDS has enacted legislation recognizing their maritime boundaries and zones, and sovereignty as fixed, irrespective of changes to its physical coastline.
3. Second, there are now more examples of cross-regional practice and opinio juris. The 2023 Declaration by the Leaders of the PIF on the Continuity of Statehood“affirms that international law supports a presumption of continuity of statehood and does not contemplate its demise in the context of climate change-related sea-level rise”, and goes on to “declare that the statehood and sovereignty of [PIF Members] will continue.”[7]
4. This past September, the 39 heads of state and government of AOSIS made a similar declaration, declaring that “international law is premised on a principle of continuity of statehood, consistent with broad state practice over the past century.”[8] Recognizing the practice and opinio juris of states, this use of principle, rather than presumption, was deliberate.
5. The AOSIS Declaration affirmed that “consistent with the principles of equity, fairness and sovereign equality of states, statehood cannot be challenged under any circumstances of climate change-related sea-level rise”[9]
6. It further proclaimed that “consistent with the right to self-determination, the statehood and sovereignty of SIDS and our membership in the United Nations, its specialized agencies and other intergovernmental organizations will cease only if another form of expression of the right to self-determination of a SIDS population is explicitly sought and freely exercised by that population.”[10]
7. The Declaration makes clear that the only way to terminate established statehood is through the exercise of the right of self-determination, as enshrined in international law. While SIDS have recognized that climate change is causing and will cause serious and irreversible impacts on land territory, the right of a population to “freely determine their political status” should not be negated by these physical changes of sea-level rise.
8. To suggest that SIDS may lose their statehood, sovereignty or membership in international organizations because of the actions of other states, is the pinnacle of inequity. It would be contrary to the principles of justice that underpin all international law.

IV. Conclusion

1. In conclusion, distinguished members of the Court, SIDS have come to you to seek clarity on international law and to reaffirm our rights as sovereign and equal states. We come as our physical world is fundamentally changing from no action or inaction on our part. Recognizing the principles of equity and self-determination, and the necessity of ensuring legal stability, security, certainty and predictability, we ask you to affirm the following:
2. First, that small island developing states are specially affected by climate change and sea-level rise and recognize the critical importance of their state practice to the clarification and development of international law;
3. Second, that the duty of cooperation in international environmental law is a general principle of international law, and the provision of financial and technical assistance is a component of cooperation;
4. Third, that maritime zones, once established and deposited in accordance with UNCLOS, and the rights and entitlements that flow from them, shall continue to apply without reduction, notwithstanding any physical changes connected to climate change-related sea-level rise; and
5. Fourth, that there is a principle of continuity of statehood in international law, and that no matter the physical changes that result from climate change, states will retain their statehood, sovereignty and memberships in international organizations.
6. Distinguished members of the Court, we thank you for your consideration.

[1]Art 56, Charter of the United Nations (adopted 26 June 1945, entered into force 24 October 1945) 1 UNTS XVI.

[2] Principle 7, Rio Declaration on Environment and Development (adopted 14 June 1992) UNGA Res 1/CONF.151/26 (Vol I) (12 August 1992)

[3]Gabčikovo-Nagymaros Project (Hungary/Slovakia), Judgment, I. C. J. Reports 1997, p. 78, para. 140

[4] Paris Agreement (adopted 12 December 2015, entered into force 4 November 2016) UNTS 54113, art 9(1).

[5] Pacific Islands Forum (PIF) submission to the International Law Commission, 2019, available at: https://legal.un.org/ilc/sessions/72/pdfs/english/slr_pif.pdf

[6] 'Declaration on Preserving Maritime Zones in the Face of Climate Change-related Sea-Level Rise' (Pacific Islands Forum, 2021)

[7] 2023 Declaration on the Continuity of Statehood and the Protection of Persons in the Face of Climate Change-Related Sea-Level Rise, preamble para 12.

[8] AOSIS Declaration on Sea-Level Rise and Statehood (adopted 23 September 2024, New York)

[9] Ibid

[10] Ibid