Ashish Singh*


Among the umpteen threats posed by climate change is the impact on the extent of the maritime claims of the states. This essay briefly discusses climate change before relating it with the rise in sea level. It examines the ways in which the maritime jurisdictional claims of coastal states may be impacted due to sea-level rise. In particular, the traditional way of dependence on the baseline as a starting point to measure maritime jurisdictional claims of the state is problematic given that there is a possibility of baseline retreating inland due to increase in the level of the sea. Further, it identifies and explores key threats to maritime zones and tries to investigate the options for coastal states to address such threats. Finally, it concludes that the physical measures to protect maritime claims are not only costly but unrealistic as well. Thus legal option should be explored and efforts to be made to fill up the lacuna in the existing laws relating to climate change and maritime claims.

Keywords: Climate Change, Sea-level rise, Coastal impacts, Green House Effect, Insular Status.


The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Hereinafter IPCC) shows high confidence that not only is the global climate changing but accelerating. There is mounting evidence of global warming, large scale melting of glaciers and ice caps that result in a rise in global average sea level.[1] While debates continue to know the causes, many analysts link it to the Greenhouse effect.Coastal states and small island countries remain most susceptible to the brunt of Climate Change as even a slight rise in sea level has the potential to submerge their land areas. This majorly applies to the states that are at low elevations, such as Republic of Marshall Island, Maldives, Tuvalu and Kiribati.

United Nation Convention on Law of Sea neither indicates the ambulatory nature of baseline nor the loss of states claims to Maritime Zones. But scholar such as Caron, Soon and Rayfuse have propounded that the baselines are ambulatory. Thus with the change in baseline maritime jurisdiction also changes. As per this theory, maritime zones measured from normal low-water baseline will retreat if such baseline recedes inland due to rise in sea level. This will lead to erosion in the scope of the state’s maritime claims. Further, there is a threat to the insular status of the features concerned as sea-level rise has the potential to reduce their maritime jurisdictional claims. Some island states are in danger of total inundation of their territory that may result in loss of their status as a state.

Coastal states can opt some measures to address and adapt to challenges that pose a threat to their maritime jurisdictional claims due to rise in sea level. With a view to protect  maritime claims construction of sea defences such as wave reduction structure, sea walls and rock offshore breakwaters can be done. But this physical protection of the coast from the sea level rise is largely unrealistic, save in exceptional situation. Moreover, the key drawbacks of such measures are the costs and threat of unanticipated ‘knock-on’ effects. Thus, Alternate legal option should be explored.

Though UNCLOS attempts to create norms for determining boundaries it did not anticipate that the rise in sea level would make radical shifts in coastline and changes in insular status. Consequently, it does not provide mechanisms to deal with the same. This UN Convention does, however, provides for permanent fixing of both baseline and maritime zones. Adaptive legal responses can be assessed to provide for the fixing of normal baseline and maritime zones. Different legal and policy options needed to be explored and assessed in order to protect the interest of Coastal states and small island countries.


In the twenty-first century, climate change and their effects are widely recognized, but the effects on the maritime zones have received surprisingly less attention. It may be because the impact is not readily visible. Certain global readjustment is already underway due to changing climatic conditions especially warming climate. This will not only continue but accelerate regardless of what steps are taken to mitigate emissions. These readjustments include rising sea level, global temperature and melting glaciers.

There are shreds of evidence to show that not only there is a change in global climate but also rise in the level of the sea. The UN Secretary-General issued a report which shows that there is an increase in the sea level faster than expected and warned that if the greenhouse gas emissions continue at the current level, the sea will rise by 0.5 m to 1.4 m by the end of this century.[2] The disintegration of ice sheets and thermal expansion of the ocean is the major sources to make the sea level rise. Increase in the atmospheric temperature creates ‘steric effect’ that gradually and incrementally makes ocean warm. As the warm water expand, sea level increases.[3] With regard to the disintegration of ice sheets, there is uncertainty in IPCC’s methodology as it does not take into account their potential loss. This has led to a consensus that IPCC is wildly optimistic in its estimates.[4] It should be noted that even a modest rise in sea level as estimated by IPCC itself can have significant consequences for the states. Even slight vertical change in the level of the sea can make changes in the location of baselines. This can be catastrophic as the majority of the world population is concentrated on coasts.

Aside from giving rise to sea level, climate change especially global warming causes various extreme weather events that damage the coastal areas. This makes coastal states and small island states which are at developing stage more vulnerable to the impact of extreme maritime weather and rising sea level.

  1. Shifting Maritime Claims Due To Ambulatory Baselines

In the context of maritime jurisdiction, the normal baseline of a state is the interface between the land and sea. Such baselines provide the beginning point to measure the zones where the coastal states have claimed their jurisdiction, so these are of fundamental importance to coastal states’ claims to maritime jurisdiction. These baselines are often termed “territorial sea baselines”, along with the claims not to the territorial sea, such baselines are also crucial to all other maritime zones the contiguous zone, exclusive economic zone (EEZ) and continental shelf as all of these zones of maritime jurisdiction are measured from relevant baselines.[5] Another important feature is that they represent the outer limit of a State’s land territory.[6] Apart from these issues, baselines are also crucial to the delimitation of maritime boundaries.

The rules of international law concerning the delimitation of maritime boundaries are largely codified under the United Nations Convention on the Law of the Sea (LOSC) of 1982,[7]  and its predecessors, notably the Conventions of 1958.[8]The provisions given in Convention deals with baselines and the delimitation of maritime boundaries are often reflective of customary international law. The ICJ in Romania/Ukraine case held that those base points on the coast should be chosen that “mark the significant change in the direction of the coast, in such a way that the geometrical figure formed by the line connecting all these points reflects the general direction of the coastline”.

A potentially problematic counter-point to this scenario, especially in an era of sea-level rise, is that the traditional and generally-accepted connection between the location of normal low-water baselines and the limits of maritime zones of jurisdiction dictates that the maritime jurisdictional zones measured from these baselines also changes with the change in normal baselines.[9]  Owing to their especially low lying nature, the low water normal baselines on which coastal States rely to measure their claims to maritime jurisdiction are often unstable and are prone to both changes over time and to inundation as sea-level rises. The rising sea levels will inevitably result in the normal, low-water line baseline receding inland. Under the present baselines regime, this is very likely to have significant ‘knock-on’ impacts on the limits of maritime claims. In such scenario, the maritime zones measured from the normal baselines will also recede with the receding normal baselines further causing the retreat of the maritime zones measured from them, leading to a potentially major diminution in the scope of the relevant coastal State’s maritime claims.

This phenomenon is not new. It has been known since a long time that coastlines are dynamic, so normal baselines can change significantly over time or “ambulate”. There is a longstanding tension to show the ‘true’ location of the normal baseline and the need for stability, clarity and certainty in maritime limits from the viewpoint of management and enforcement.

  • Implications

Building on the above we can derive that maritime limits constructed from normal baselines are vulnerable to shifting as the normal baseline keeps ambulating over time. If maritime jurisdictional limits are always changing in a similar way, it will raise several enforcement implications. From the viewpoint of enforcement agencies, clarity, stability and certainty are highly desirable qualities in the context of maritime jurisdictional limits and the ambulatory nature of such limits is very unwelcome, as it has the potential to undermine confidence in those limits and cause confusion. Overall, the fact that baselines and thus maritime limits are capable of shifting has the potential to result in jurisdictional uncertainty, disputes and conflict. Particularly, where enforcement activities are close to the limits of a particular zone of maritime jurisdiction, it may later emerge that the maritime limit was reliant on a base point that no longer existed.

It is important to note that the impact of the rise in sea level is not likely to be evenly distributed. The whole baseline of a coastal State is not created equal. Similarly, a coastal State’s entire baseline does not contribute towards the construction of the outer limits of its maritime claims.[10] Only certain base points along the normal baseline are material for the limits of the maritime zones, with the length of the arcs from the contributing base points fixed by the breadth of the maritime zone for which the outer limit is being constructed a maximum of 12 nautical miles (nm) for the territorial sea, 24nm for the contiguous zone and 200 nm for the EEZ. So, the whole of a normal baseline is not of equal ‘worth’ to generate zones of maritime jurisdiction. There will be some fixed critical base points that may be the focus of efforts to preserve maritime claims. This, in turn, may have an effect on the protection of those certain base points for the purpose of preserving maritime jurisdictional claims arising from them.


There are certain measures which need to be adopted in order to face the threats to critical base points. This is necessary for the preservation of the jurisdiction over the marine zones associated with them along with the marine resources which lie within them.

  1. Natural Equilibrium

Doing nothing is one policy choice. The coastlines would be allowed to discover their own “natural equilibrium” and the necessity to construct costly sea defences would be avoided.[11] It is evident that a passive response like this would lead to disadvantages. If coastlines are permitted to discover their natural equilibrium as sea-levels rise then there would be implications of the coastlines retreating landward which would result in low-lying coastal zones and potentially include populated areas along with essential coastal habitats such as the wetlands for inundation. Such an option is not as lucrative for the small island states as it is for the mainland continental States. A reason for this is the severe territorial restrictions on the extent of these states. So the scope for the retreat of the coastline before the islands constituting the State disappear entirely is very little. As per the apt comment by Freestone, the ‘do nothing’ approach “is not a politically passive option.”[12]

  •  Building Castles

An interventionist policy which was created in order to preserve the coastline from erosion lies as a substitute choice with a long pedigree in the context of volatile coasts. It has been termed as a “bulkhead policy.[13] The implementation of such a policy is followed by the vision of the creation of defences in the sea such as sea walls, barriers along with structures of wave reduction, revetments, breakwaters which are offshore, rock armours and gabions.  A classic example would be the Maldives which is reportedly seeking sand from regions with lagoons in order to construct more than one island with the reinforcement of concrete which can be utilised in the provision of safe shelters for the inhabitants of the country.[14] “Huge islands” like these would reportedly be subjected to an elevation of around three meters above sea level, as compared with the large majority of the land territory of the country, which is barely a meter above mean sea level.[15]

The major disadvantages of steps like these are the heavy costs and approaches like these are shrouded in unrealism and are deemed inappropriate to several contexts of islands. What is advocated in place of it is a sustainable management and ecosystem-based approach.

  • Legal Fixes

From what has summarized above, it has long been approved that coastlines are high powered. In the case of displacement or erosion, the normal baseline will be altered. This can result in “knock-on” effects on the external limits to maritime zones measured from them. The goal involving the retention of existing maritime claims could be fulfilled by fixing the normal baseline or the limits of the maritime jurisdictional claims of coastal States.

  1. Fixing Normal Baselines

Trying to safeguard normal baselines by interfering with it physically is something that may prove to be unrealistic in the context of significant sea-level rise a number of lawful measures and might end up providing for the retention of existing maritime jurisdictional claims. Such approaches might prove to be unsuccessful when it comes to resolving the issue of the influx of sensitive low-lying areas, but states which were affected would prove to be instrumental in getting a major asset to the table during negotiations to accommodate inhabitants who may ultimately be shifted.

The certain lawful policy response is derived from LOSC Article 5. According to the policy the low-water line, and eventually the normal baseline, is “marked on large-scale charts officially recognized by the coastal State.”[16] The choice of the chart, and thus low-water line/normal baseline, lies with the coastal State. This gives the state the authority to choose a chart which would prove to be more beneficial to it. From an international perspective, such an approach would come with its share of issues. However, it might prove to be effective domestically.

  1. Fixed  Outer Claims

The limits being dissevered from mobile normal baselines is the outcome of the choice of repairing the outer limits of coastal State maritime claims. As previously noted, international maritime boundaries, once agreed, will not be subjected to change except through agreement among the parties involved. The permanent fixing of outer continental shelf limits shall be allowed by the LOSC. In agreement with the Article 76 of the LOSC, it has been deemed that where the continental margin surpasses 200 nm from the coast, a State by the coast wishing to confirm its independent authority over regions of continental shelf seaward of the 200 nm limit is bound to make a submission to a particularized United Nations non theoretical body which is known as the United Nations Commission on the Limits of the Continental Shelf (CLCS). Afterwards, recommendations will be made by the CLCS to the coastal State on the basis of which the coastal State can initiate limits that are “final and binding”[17] It has been suggested that this could result in the retention of continental shelf rights, having already been fixed on an everlasting basis, even though the territory generating such continental shelf rights may have slipped underneath the waves.[18]

If State unilaterally declares the boundaries of its maritime claims, measured from normal baselines, either through issuing lists of geographic coordinates or publishing nautical charts with such boundaries clearly marked then it would be considered as an option.[19] Once again, however, while this approach would probably be efficacious as a topic of domestic law. Disputes may arise in the international context, as other States would not be obliged by unilateral claims like these.


Ultimately, there is a need for a new process in order to fix normal baseline and maritime claims of the coastal and island states. In this regard there are proposals but they are not of recent vintage, threats posed by global climate change especially sea-level rise and changing maritime zones provide added impetus to the hunt for a new law. This law may develop through state practice if they choose any specific charts for measuring their maritime claims or simply declaring their maritime jurisdiction. This chart could be deposited to the UN Secretary-General in the same way as it is lodged for the straight and archipelagic baselines. These actions could lead to the formation of new customary law that provides for fixing of ambulatory baselines and consequently fixing of maritime zones which may not ordinarily subject to change. However, States need to coordinate for such an approach which can be achieved by the help of the regional technical and political organisation.

It is to be noted that though UNCLOS is considered as ‘Constitution of the Oceans’ drafters did not anticipate the rise in sea level and they assumed that there would be stability in the normal baseline that is used to measure the maritime claims. And even case law on maritime delimitation provides little responses. This creates a lacuna in the existing law as this does not provide the ways to deal with changing normal baseline due to the effect of climate change. This puts the small island states whose very existence is threatened at a very vulnerable position. Moreover, these coastal and island states have contributed the least in the increase in global warming and it will be profoundly inequitable that these states suffer the most of the disastrous impact of the changing climate. Therefore, a case can be made on the grounds of equity that such states can fix their baseline and maritime zones in order to retain their rights over resources contained therein.

*Student, National Law University Odisha

This essay has been selected for publication through the 1st NLUO-Ganesh & Co. National Maritime Law Essay Writing Competition, 2019.

[1] John Church and Neil White, A 20th Century Acceleration in Global Sea-level Rise 33 Geophysical Research Letters (2006).

[2] G.A. Res.A/63/63, Oceans and the Law of the Sea (Mar.10, 2008).

[3] Climate Change 2007 Impacts, Adaptations and Vulnerability, https://www.ipcc.ch/site/assets/uploads/2018/03/ar4_wg2_full_report.pdf (last visited July 31, 2019).

[4] Anil Ananthaswamy, Going, Going…, 26 New Scientist (2009).

[5] Clive Schofield, Shifting Limits: Sea Level Rise and Options to Secure Maritime Jurisdictional Claims 3 CCLR (2009).

[6] Id.

[7] United Nations Convention on the Law of the Sea (adopted 10 December 1982, entered into force 1 November 1994) 1833 UNTS 3.

[8] Id.


[10] Carleton and Schofield, Developments in the Technical Determination of Maritime Space: Charts, Datums, Baselines, Maritime Zones and Limits 3 Durham University (2001).

[11] Vienna Convention on the Law of Treaties (adopted 23 May 1969, entered into force 27 January 1980) UNTS 1155. 331.

[12] Freestone, International Law and Sea Level Rise 32 BRP (2019).

[13] Id.

[14] Chris Morris, Maldives Rises To Climate Challenge, BBC News Online, (Mar.17, 2009),  http://news.bbc.co.uk/l/hi/world/ south asia17946072.stm (last accessed on 21 November 2009).

[15] Id.

[16] United Nations Convention on the Law of the Sea, (adopted 10 December 1982, entered into force 1 November 1994) 1833 UNTS 3 Art 5.

[17]  Id. Art. 76(8).

[18] AHA Soons, The Effects of Sea Level Rise on Maritime Limits and Boundaries 37 Cambridge Law Journal (1990).

[19] Hayashi, Sea Level Rise and the Law of the Sea: Legal and Policy Options Review of Island Studies (2013).


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