Sea Level Rise & its Implication in International Law


Various reports suggest that the rise in mean sea-level (“RSL”) is a cause of great concern for the world. Primarily caused by global warming, it has far-reaching effects, especially on island States such as Maldives, Micronesia, Hawaii, Republic of Kiribati, and even the low-lying areas of Bangladesh and India. The potential hazards of RSL were noted by the International Law Commission (“ILC”) in 2019. This article explores four different dimensions of the possible legal implications of RSL, resulting in partial as well as total submersion of land and relocation of its people.

Maritime Law and Jurisdictional Issues

Articles 1 and 2 of the Convention on the Territorial Sea and the Contagious Zone, provide that the coastal State’s sovereignty extends over its territorial sea and to the airspace and seabed and subsoil thereof, subject to the provisions of the United Nations Convention on the Law of the Sea (“UNCLOS”) and of international law. The UNCLOS distinguishes between four types of baselines in order to measure its maritime jurisdictional zone, namely, “normal baseline”, “straight line”, “straight baselines” and “straight archipelagic baselines”. A State’s maritime zones are usually measured from the “normal baseline” recognized by the coastal State on its official charts, as per Article 5 of UNCLOS. From this baseline, States may measure their territorial sea, contiguous zone, exclusive economic zone, and continental shelf.

The primary question is whether, with the RSL, the baselines are ambulatory, i.e. whether they move along with physical changes in the coastlines. While in international law further expansion of baselines is credited to the State, a similar analogy to the reduction in coastlines should imply it being ambulatory. While this issue was brought up before the Permanent Court of Arbitration, the question was unanswered as the Tribunal held that it wasn’t relevant for the arbitration. But the report by the Baselines Committee of the International Law Association (“ILA”) states that baselines are ambulatory, irrespective of it being updated on the charts. On the one hand, if coastlines are held to be ambulatory, certain low-lying States might completely cease to exist in the absence of special provisions. On the other, fixing the baselines would create inequalities in the States’ relationships with the maritime areas, and the extent of submerged land would vary. Thus, there exists a dilemma on the ambulatory nature of coastlines.

The UNCLOS did not envisage the consequences of RSL as it was tailored to the geographical circumstances prevalent at that time, not the ones occurring in the future. Therefore, these concerns have led to the formation of bodies such as the Alliance of Small Islands States (“AoSIS”) which address the vulnerability of small islands to climate change. While artificial conservation of coastlines is permitted under international law, new artificial islands created for preventing a State’s coastline from diminishing is not recognized, and they do not possess the status of islands. Other remedies for States to protect their territories are either establishing boundaries via delimitation agreements, “freezing” titles, causing the baselines to be fixed as a part of customary international law by consistent practice and opinio juris.

Protection under Human Rights-based laws: Need of the Hour

While the UN Human Rights Council (“UNHRC”) has acknowledged the adverse effects of climate change on the effective enjoyment of human rights, it simultaneously observes that International Refugee Law and migration law are unlikely to offer protection to “climate change refugees”. The Refugee Convention, 1951 defines a refugee as any person who “owing to a well-founded fear of being persecuted … is outside the country of his nationality, and is unable to avail himself of the protection of that country”. This definition does not envisage victims of climate change. An argument can be made that climate change falls under the larger ambit of “disaster”. The Committee on Economic, Social and Cultural Rights (“CESCR”) repeatedly addressed that "whenever an individual or group is unable, for reasons beyond their control, to enjoy the right to adequate food by the means at their disposal, States have the obligation to fulfil (provide) that right directly" and underlined that "this obligation also applies for persons who are victims of natural or other disasters. More generally, it held that "States parties have a joint and individual responsibility ... to cooperate in providing disaster relief and humanitarian assistance in times of emergency". Hence, there is no surety as to whether these “climate refugees” are entitled to protection. A lot has to do with the hazardous implications of RSL not being in the spotlight, which is also quite often neglected by various governments.

A step in the right direction was taken via the 2018 Sydney Declaration” Report by the Sea Level Rise Committee which purported to codify and create the relevant norms of international law for assisting the affected persons. Considering that refugee protection laws are “reactive”, there is an urgent need to include “climate change refugees” in the definition or a new law. Since it is a foreseeable act, an orderly and structured evacuation plan is the need of the hour, which can ensure the reduced likelihood of humanitarian emergencies and displacement.

Contractual Law Disputes: Analyzing the State obligation in the light of treaties and conventions

As was discussed in (I), the boundaries between States could be formed through an agreement. Generally, two neighboring states negotiate a maritime boundary delimitation agreement on an equidistant line between their coastal guidelines. Now, the RSL can cause a landward shift in one of those baselines. Therefore, the question arises as to the validity of the existing agreement, dealt in Article 62 of the 1969 Vienna Convention on the Law of Treaties (“VCLT”). It allows for “terminating a contract on a fundamental change in circumstances”. But the application of this doctrine is clearly excluded to a treaty establishing a boundary. The stability of maritime boundaries is also reflected in customary international law and judgements of the International Court of Justice (“ICJ”). This position is strengthened by the Sea Level Rise Committee which prohibits the interpretation that the RSL implies a “fundamental change in circumstances”. But some scholars argue that the contract could be terminated as there is a “fundamental change of circumstances”, especially when the parties had foreseen changes in the treaty. Parties may also withdraw from or even suspend the treaty. Probably a more fundamental contractual issue could be the legality of a contract if one of the parties’ territory ends up being submerged or uninhabitable. The question that would necessarily arise is if that party is a “State” in the first place, more on which is discussed elaborately in the next section.

Statehood and State Identity

The RSL poses the predicament as to what happens if the territory of a State disappears or becomes uninhabitable due to salinization. Various scholars and contemporary legal instruments such as UNCLOS inculcate the position that “all maritime establishments derive from the land”. Even the ICJ affirmed that “land is the legal source of the power which a State may exercise over territorial extensions to seaward”. It is in this context one must analyze the importance of territory for a State to claim its Statehood.

Article 1 of the Montevideo Convention provides the criteria for Statehood, which include a) A permanent population, b) A defined territory, c) Government, and d) Capacity to enter into relations. Out of the four, the territory is the most fundamental one. The creation of States is heavily dependent on these factors, and it has been followed in practice. Though the extinction of entire territory doesn’t seem likely in the near future, the question is, should the “extinction” of a State be determined by the same factors stipulated in the Montevideo Convention? Some authors argue that Statehood will cease long before the loss of territory, as at a particular point in time, the territory will become uninhabitable, and therefore many countries may lose their independent status. In contrast, some argue that the creation and extinction of States cannot be based on the same factors, and in fact, there is a strong presumption in favour of the continued existence of a State.

An interesting angle of maintaining sovereignty is by using jus cogens norms read with Article 2 of Draft Articles on Responsibility of States for Internationally Wrongful Acts. The loss of territory is equated to other States’ “violation of a fundamental norm of the international legal order”. This implies that threatened States could argue that their loss of territory is the result of unlawful emissions that worsen climate change and cause quicker acceleration of RSL. The lawfulness of emissions could be related to obligations mandated by the UNFCC and the Kyoto Protocol.

Thus, a strict interpretation of the Montevideo Convention may spell trouble for States, but there are defenses that can be taken to retain their sovereign status.


Through this article, the negative impacts of RSL are vehemently visible and thus, should warrant a careful and well-researched plan of actions by States in an international arena. There are various methods via which the inevitability of RSL can be slowed down. While some of them might be practical, it may require international cooperation on a large-scale, while others may be useful, but not without drawbacks. States in danger can use methods such as the construction of sea defences, such as sea walls, groynes and wave reduction structures, or acquire new land, etc. On a global level, States should strictly abide by the Paris Climate Change Agreement and the Kyoto Protocol. While the RSL is not a novel issue, it certainly merits a deeper understanding from a legal perspective.

Title image source: American Society for Mechanical Engineers

This article has been written by Anshul Ramesh who is a fourth year law student pursuing BA.,LL.B. (Hons.) from O.P. Jindal Global University, Sonipat, India.