Landmark ITLOS legal opinion – States must protect oceans and marine biodiversity from GHG emissions

Executive Summary

• On 21 May 2024, the International Tribunal for the Law of the Sea (ITLOS or the Tribunal) delivered an advisory opinion (the Opinion), finding that states have a legal obligation to protect the world’s oceans and marine biodiversity from climate change in accordance with the United Nations Convention on the Law of the Sea (UNCLOS).
• The Opinion clarifies states’ specific obligations under (but not limited to) Part XII of UNCLOS to (a) prevent, reduce, and control pollution of the marine environment caused by the effects of climate change, particularly ocean warming, sea level rise and ocean acidification, caused by human induced GHG emissions; and (b) protect and preserve the marine environment from these impacts.
• One of the most significant written submissions came from the International Maritime Organization (IMO), which set out that the specific obligations developed by the IMO itself are consistent with the UNCLOS framework on setting international rules and standards in the shipping sector, given the wide membership of the IMO and the uptake of existing instruments, such as MARPOL.
• Although the Opinion is not legally binding, the 169 signatory states of UNCLOS will be expected to implement legislation and effective enforcement measures to ensure compliance with their obligations to prevent marine pollution caused by GHG emissions and protect and preserve marine ecosystems. Commercial shipping may lead the way in testing decarbonisation solutions, as is already the case with green shipping corridor initiatives.
• Key findings of the Opinion include the following:
  • Greenhouse gas (GHG) emissions are marine pollution under UNCLOS, as GHGs (a) are  considered to be a substance or energy; (b) are being introduced by humans, directly or indirectly into the marine environment; and (c) have caused or are likely to result in deleterious effects to the marine environment.
  • States must take all necessary steps to prevent, control and reduce, anthropogenic GHG emissions, including not only ocean-based emissions from vessels, but also land- and air-based emissions. States are required to act with strict “due diligence”.
  • States’ obligations go beyond existing climate change commitments: compliance with the Paris Agreement alone may not be sufficient to discharge states’ obligations.
  • Developed countries must take the lead in emissions reduction measures and must provide assistance to developing nations.
  • States have a duty to prevent “transboundary harm”. The Tribunal clarified that UNCLOS imposes strict and specific obligations on states to adopt all measures to ensure that anthropogenic GHG emissions within their jurisdiction or control do not cause damage to other states and their environment, and that any marine pollution from such emissions does not spread beyond their national jurisdiction.
  • States are required to monitor the risks and effects of marine pollution, conduct environmental impact assessments for any activity which “may cause substantial pollution to the environment or significant and harmful changes thereto through anthropogenic GHG emissions”, and publish reports on the findings.
  • States are legally obliged to protect and preserve the marine environment, which includes restoring degraded habitats and ecosystems.
  • Finally, the Tribunal found that States are required to cooperate directly, continuously, meaningfully, and in good faith to meet these obligations.

Introduction

On 21 May 2024, the International Tribunal for the Law of the Sea (ITLOS or the Tribunal) delivered a highly anticipated advisory opinion finding that states have a legal obligation to protect the world’s oceans and marine biodiversity from climate change (the Opinion). This is the first of three advisory opinions clarifying states’ obligations to address climate change under international law to be issued from international courts, with opinions from the Inter American Court of Human Rights (IACHR) and the International Court of Justice (ICJ) expected later in 2024 and 2025, respectively.

Where the ICJ and IACHR legal opinions are broad in scope, the ITLOS Opinion focuses purely on states’ obligations to mitigate climate change impacts on the ocean and marine ecosystems, as governed by the 1982 United Nations Convention on the Law of the Sea (UNCLOS). The Opinion builds on existing efforts to decarbonise the maritime industry, but its precise impact on commercial shipping and other marine activities is yet to be seen.

In this article, we give a comprehensive overview of the Opinion, including a detailed analysis of its main findings, and offer insights on the potential implications for the marine industry. 

UNCLOS and ITLOS: the Constitution and Guardian of the Ocean

UNCLOS is an international treaty agreed in 1982 (entered into force in 1996) that establishes a comprehensive legal framework regulating the ocean, its use, and all marine resources (including natural and cultural resources). In this sense, UNCLOS is known as the Constitution of the Ocean. UNCLOS sets out clear rules regarding states’ navigational rights, maritime zones and boundaries, and economic jurisdiction.

Part XII of UNCLOS, titled ”Protection and Preservation of the Marine Environment” contains comprehensive provisions relating to marine environmental protection and preservation (See Articles 192, 194), including obligations on signatory states to prevent marine pollution “from any source”, meaning ocean-, land- and air-based sources (see Articles 194, 207, 212, 213).  

ITLOS is a specialist, independent judicial body established under UNCLOS to adjudicate all disputes and matters arising out of the interpretation and application of UNCLOS. Where UNCLOS is the ocean’s Constitution, ITLOS is its Guardian. The Tribunal comprises 21 independent experts in the law of the sea, each elected by signatory state parties, and is regarded as the highest judicial authority on the oceans.

Background to the Opinion

The Opinion was requested in December 2022 by a Coalition of Small Island States on Climate Change and International Law (COSIS), which was established during COP26 in 2021 by island states that are heavily dependent on the marine environment and highly vulnerable to climate change (the Request).

At the time of submitting the Request, COSIS included Antigua and Barbuda, Tuvalu, The Republic of Pilau, Nieu, The Republic of Vanuatu and Saint Lucia, but, subsequently, was acceded to by Saint Vincent and the Grenadines, Saint Christopher (Saint Kitts) and Nevis, and the Commonwealth of the Bahamas. All COSIS members are UNCLOS signatories.

The Request sought clarity on states’ specific obligations under (but not limited to) Part XII of UNCLOS to (a) prevent, reduce, and control pollution of the marine environment caused by the effects of climate change, particularly ocean warming, sea level rise and ocean acidification, caused by human induced GHG emissions; and (b) protect and preserve the marine environment from these impacts.

Importance of oceans and marine ecosystems

Oceans have an important regulating role in the global climate system. The ocean is the world’s largest natural carbon sink, sequestering nearly a quarter of the carbon dioxide emitted by humans, while also storing heat trapped in the atmosphere and slowing global temperature rise. The Intergovernmental Panel on Climate Change (IPCC) 2019 Report found that it is “virtually certain that the global ocean has warmed unabated since 1970 and has taken up more than 90% of the excess heat in the climate system”.

Marine and coastal ecosystems (including mangroves, salt marshes, seagrasses, and seaweed forests) play a similar vital role in sequestering carbon dioxide from the atmosphere, while also offering protection from and minimizing the impacts of extreme weather events, thus contributing to nations’ mitigation and adaptation strategies. For example, coastal mangroves act as wave and wind breakers, providing natural protection against tropical storms.

However, the IPCC found with high confidence that human-driven climate change has caused “substantial damages and increasingly irreversible losses” in the ocean and marine ecosystems, and directly linked climate change with sea level rise, rising sea temperatures, marine heatwaves, ocean deoxygenation, and ocean acidification – each of which has disastrous effects on marine ecosystems, marine life, and the lives and livelihoods of communities dependent on them, particularly vulnerable island states. For example, the IPCC found that ocean warming has more than doubled since 1993  with the frequency of marine heatwaves doubling since 1982, negatively impacting both the nutrient levels in the ocean and the ocean conditions required to sustain ocean life.

Furthermore, due to the melting of ice caps (caused by rising global air temperatures) and the thermal expansion of water (caused by rising global ocean temperatures) driven by human influence, sea levels have risen by 0.2 metres between 1901 and 2018. As well as increasing the likelihood of tropical cyclones and storm surges, rising sea levels pose an “existential threat” to small island states (many of which form part of COSIS) and to some low-lying coastal communities.

Human life depends on the ocean, which provides us with food, livelihoods, culture, and half of the oxygen in the atmosphere. The islands and low-lying states which have contributed the least to the climate crisis are facing its worse effects.

Global significance of the Opinion  

Given the global importance of the questions before the Tribunal, it invited written submissions from numerous amici curiae or ”friends of the court” (meaning parties with no direct legal interest in the proceedings). Written statements were submitted by 34 states party to UNCLOS (including the UK, the EU and China); 9 intergovernmental organisations (including COSIS, the UN, the International Maritime Organisation (IMO), the International Union for the Conservation of Nature, the Pacific Community, the United Nations Environment Programme, the African Union, the International Seabed Authority and the Food and Agricultural Organisation of the United Nations (FAO); and 10 non-governmental groups (including the UN Special Rapporteur on Human Rights & Climate Change, ClientEarth, the High Seas Alliance, the WWF), although these did not form part of the formal case file. A summary of these written submissions can be found here.

Under ITLOS proceedings, amici curiae briefs are often used to provide the Tribunal with accurate and reliable scientific data, relevant to the matter under consideration, thereby enhancing the quality of its findings. Amici curiae briefs are different from ”third party interventions” permitted under Article 31(1) of the ITLOS Statute, in that amici curiae submissions cannot assert claims, influence the course of proceedings, present witnesses for examination, or offer general advice; amici curiae (for example, the NGOs identified above) participate to assist the Tribunal in the proper administration of justice.

Similarly, many party states and intergovernmental organisations made oral statements during the hearing, which consisted of 18 public sittings in Hamburg, where ITLOS is headquartered, during September 2023.

One of the most significant written submissions came from the IMO, given that the organisation has 175 Member States. As a specialised agency of the United Nations, IMO is the global standard-setting authority for the safety, security, and environmental performance of international shipping[1].

The significance of IMO’s submissions is highlighted by the reference in UNCLOS to “competent international organisations” in relation to specific subject matters covered by the Convention[2]. IMO is one such organisation and, therefore, the specific obligations developed by the IMO are consistent with the UNCLOS framework on setting international rules and standards in the shipping sector. In particular, the International Convention for the Prevention of Pollution from Ships, 1973, and its Protocol of 1978 (MARPOL) sets out the legal regime to address air pollution from ships[3].

Given that MARPOL’s Annexes cover between 96-98% of world tonnage, and are mandatory, IMO’s submission that these are “generally accepted rules and standards” for the purposes of UNCLOS[4] is significant and establishes a firm link between the Opinion, itself non-binding (see section on this below), and the IMO Conventions, which are mandatory and enforceable under the IMO Member State Audit Scheme, setting this out as a potential mechanism to ensure the Opinion is given its proper weight.

Legal status of the advisory opinion

Advisory opinions are legal clarifications of existing obligations, rather than decisions in contentious proceedings, and as such are not directly legally binding on any state. However, the 169 signatory states are obliged by UNCLOS to adopt national laws, regulations, and other necessary legal instruments, to comply with their obligations under UNCLOS (see, for example, Articles 207, 211 and 212) and to cooperate with other states in establishing international rules, standards, practices, and procedures[5]. This means states will need to enact or update existing domestic legislation targeting GHG emissions from all sources.

However, enacting legislation to comply with UNCLOS alone is insufficient. States are required by UNCLOS to enforce them, as well as any laws and regulations that have been implemented to comply with applicable international rules and standards addressing marine pollution, which includes binding obligations under other treaties (see UNCLOS Articles 213, 217 and 222)[6].

As such, states will be expected to implement legislation and effective enforcement measures, to ensure compliance with their obligations to prevent marine pollution caused by GHG emissions and protect and preserve marine ecosystems. Such legislation will undoubtedly impact industry and businesses (particularly those that are high-emitters).

Furthermore, advisory opinions are considered highly influential tools that provide policy signals and guidance to governments, and – importantly – to national courts on the evolution of international law. While ITLOS expressly fails to address the question of responsibility and liability for climate change (the Request merely sought clarification of states’ primary obligations under UNCLOS – see paragraphs 145-148 of the Opinion) and does not mention the legal consequences for states that breach the newly-clarified obligations, it sets a clear legal precedent that reinforces states’ existing obligations to act on climate change and will likely lay the foundations for liability in other fora. For example, it is likely that the Opinion will be used as credible and authoritative evidence in lawsuits seeking state or corporate accountability for harms to the ocean and marine ecosystems caused by anthropogenic climate change.

Findings and implications for the marine industry

In relation to the first question set out in the Request, regarding states’ obligations to prevent, reduce and control marine pollution caused by anthropogenic GHG emissions, the Tribunal made the following landmark findings:

1. Greenhouse gas emissions are marine pollution under UNCLOS[7]

Article 194 of UNCLOS requires states to take “all measures […] necessary to prevent, reduce and control pollution of the marine environment from any source”.

“Pollution of the marine environment” is defined in Article 1(1)(4) of UNCLOS as  “the introduction by man, directly or indirectly, of substances or energy into the marine environment, including estuaries, which results or is likely to result in such deleterious effects as harm to living resources and marine life, hazards to human health, hindrance to marine activities, including fishing and other legitimate uses of the sea, impairment of quality for use of sea water and reduction of amenities”.   

Although this definition does not provide examples of pollutants that classify as marine pollution, Section 5 of Part XII of UNCLOS provides a detailed framework for the different sources of pollution of the marine environment, including pollution by dumping (Art 210), pollution from vessels, such as that caused by accidents (Art 211), and pollution from or through the atmosphere (Art 212)[8]. Practical examples may include contaminated cargo following a fire (see “MSC FLAMINIA” – Court of Appeal affirms High Court’s position on who can limit liability (and who cannot)) and oil spills affecting the coastline (see Continuing nuisance, forum shopping and an oil spill).

For a substance to be considered marine pollution, it must (a) be a substance or energy; (b) be introduced by humans, directly or indirectly into the marine environment; and (c) have caused or be likely to result in deleterious effects to the marine environment[9].

After detailed analysis, the Tribunal concluded that GHGs (“[g]aseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation”, the most common of which are carbon dioxide, methane, and nitrous oxide[10] [54],) satisfy these criteria and are a form of marine pollution. In particular, the Tribunal confirmed that, “through the introduction of carbon dioxide and heat (energy) into the marine environment, anthropogenic GHG emissions cause climate change and ocean acidification”, which result in deleterious effects, including sea level rise, harm to living resources and marine life, hazards to human health, hindrance to marine activities, including fishing and other legitimate uses of the sea, impairment of quality for use of sea water and reduction of amenities[11]. The significance of this finding should not be understated.

2. States must take all necessary steps to prevent, control and reduce, anthropogenic GHG emissions

Since GHG emissions are a form of marine pollution, the Opinion found that states, therefore, have an obligation under Article 194(1) of UNCLOS to take all “necessary measures” to prevent, control, and reduce them. This applies to all GHG emissions, not just ocean-based emissions from vessels at sea, but also land- and air-based emissions (for example from cars and aircraft), which states are required to reduce in accordance with other international standards and rules[12].

The Tribunal clarified that the term “necessary measures” should be understood broadly, and should include measures “designed to minimize, to the fullest extent possible, the release of toxic, harmful or noxious substances, especially those which are persistent”. In the context of climate change, such measures are generally known as mitigation measures[13], which usually comprise emissions reductions measures.

However, noting that even if anthropogenic GHG emissions were to cease entirely, their deleterious effects on the marine environment (rising temperatures, ocean acidification, etc.) would continue due to the GHGs already accumulated in the atmosphere, the Tribunal found that this obligation does not strictly call for an immediate cessation of GHG emissions[14]. Instead, states are required to prevent future or potential pollution and reduce and control existing pollution[15].

When setting domestic measures to mitigate GHG emissions, the Tribunal emphasized that these should be informed by best available science (which is key to understanding the causes, effects, and dynamics of marine pollution), but that “scientific certainty is not required”[16]. In the absence of scientific certainty, the Tribunal called on states to apply the precautionary principle in regulating marine pollution from anthropogenic GHG emissions, particularly given the serious and irreversible damage that may be caused by such pollution.

The Tribunal further clarified that states’ obligation to mitigate marine pollution from GHGs is an obligation of conduct rather than result, meaning states are required to make their “best efforts” to prevent, reduce, and control marine pollution at all times, but are not required to guarantee such result if this is not possible[17]. Instead, states are required to act with strict “due diligence”, meaning they must put in place an effective national system of legislation, administrative processes, and an effective enforcement mechanism to regulate the activities in question[18].

The Tribunal stated that the standard of due diligence must be stringent and high (meaning that the standard of due diligence, including enforcement mechanisms, must be more severe for activities more likely to cause harm[19]. Such a system, with robust control over the actions of public and private entities, is particularly necessary considering most activities that emit GHGs are carried out by private persons or companies outside of direct state control[20].  

In this respect, the Opinion builds on the existing efforts of the IMO, which has been steering its efforts towards mitigating climate change and decarbonizing the marine transport industry in recent years (Infographic - Decarbonisation in Shipping Timelines for IMO and EU measures: Clyde & Co (clydeco.com)).

However, the Opinion is in many ways broader and more immediate. Where the Opinion clarifies that states have an existing legal obligation to mitigate harm caused by all anthropogenic GHGs (noting that carbon dioxide, nitrous oxide, and methane are the most populous in the atmosphere), the IMO’s efforts to date have focused primarily on carbon dioxide emissions.

Similarly, the EU Emissions Trading System (EU ETS), the EU’s parallel efforts to decarbonize the environment and promote sustainability in the maritime sector, has also focused on carbon dioxide, with plans to extend its application to include methane and nitrous oxide from 2026. For more detail on EU ETS please refer to Clyde & Co’s series of six articles, of which the first is: EU Emissions Trading System for Maritime Transport Explained – Part 1 of 6 : Clyde & Co (clydeco.com).

3. States’ obligations go beyond existing climate change commitments: compliance with the Paris Agreement alone may not be sufficient to discharge states’ obligations

The newly clarified obligation to mitigate GHG emissions under Article 194 of UNCLOS complements (and overlaps) with states’ existing obligations to set and adopt measures to implement nationally determined emissions reduction targets (known as Nationally Determined Contributions, or NDCs) under Article 4(2) of the Paris Agreement.

Interestingly, when assessing the relationship between these legal obligations, the Tribunal found that, although the UNFCCC and the Paris Agreement (and in particular the global temperature goal and timeline for emissions reduction pathways) are useful in interpreting and applying states’ obligations to mitigate marine pollution from GHG emissions under UNCLOS, states do not necessarily discharge their obligations under UNCLOS merely by fulfilling those in the Paris Agreement[21]. In other words, states’ obligations to reduce GHG emissions under UNCLOS go further than what is required by the Paris Agreement and the UNFCCC.

The Tribunal reasoned that UNCLOS, and the Paris Agreement are separate agreements with separate sets of obligations. Although they are complementary and do not modify or limit one another[22], the Paris Agreement is not lex specialis to UNCLOS. The lex specialis doctrine, also known as generali specialibus non derogant (“the general does not derogate from the specific”), specifies that if two laws govern the same factual subject matter, the more specific law (lex specialis) overrides a law governing only general matters (lex generalis). This argument is one of the main defensive positions used by high-emitting states in the ITLOS (and ICJ) proceedings. However, the Tribunal decisively held that the doctrine “has no place in the interpretation of the [UNCLOS]”. As such, states may be required by the UNCLOS to go above and beyond their current emissions reduction plans under the Paris Agreement.

4. Developed countries must take the lead in emissions reduction measures, and must provide assistance to developing nations[23]

While noting that “all states must make mitigation efforts” to reduce marine pollution caused by GHG emissions, the Tribunal recognised that the scope and content of these measures will differ depending on states’ scientific, technical, economic, and financial capabilities[24]. In other words, countries with greater means and capabilities (typically industrialized and wealthy economies) must do more to reduce GHG emissions than those without (typically emerging and lesser-developed economies).

In this respect, the Tribunal drew inspiration from (but did not apply) the principle of common but differentiated responsibilities and respective capabilities (CBDR-RC) from Article 3 of the UNFCCC and Article 2(2) of the Paris Agreement, which, reflecting the principle of equity and differing national circumstances, calls on developed countries to take the lead by undertaking economy-wide absolute emission reduction targets.

Furthermore, states are required to make “every effort” to harmonize their policies enacted to prevent, reduce, and control marine pollution[25], and are called on to provide assistance to developing nations to help them address marine pollution from GHG emissions. This is consistent with Article 202 of UNCLOS.

Such assistance should include scientific, technical, educational, and other assistance in the form of capacity building for developing states that are particularly vulnerable to climate change[26], as well as funding[27]. Such measures must co-exist with the provisions in Articles 6, 9, 10 and 11 of the Paris Agreement addressing capacity building, technical development and transfer, and the financial capabilities of developing States[28].

5. States must make specific efforts to avoid transboundary harm[29]

The Tribunal clarified that, just because it is difficult to establish factual and legal causation between GHGs emitted in one state’s jurisdiction and marine pollution experienced in another, due to the cumulative nature of GHG emissions in the atmosphere[30], this does not mean states have no obligation to prevent transboundary pollution[31].

In fact, the Tribunal clarified that Article 194(2) of UNCLOS imposes strict and specific obligations on states to take all measures to ensure that anthropogenic GHG emissions in their jurisdiction or control do not cause damage to other states and their environment, and that any marine pollution from such emissions does not spread beyond national jurisdiction[32].

This obligation, known as a duty to prevent ”transboundary harm” is an obligation of strict due diligence. The Tribunal clarified that fulfilling this obligation could involve states being “at least as diligent as necessary to limit average global temperature rise to no more than 1.5^oC”, but that this is not the only way[33] and measures taken will vary between states[34].  

It is important to highlight here the Tribunal’s clarificatory comments on the prevention of transboundary pollution between States. This concept is already prevalent in the shipping industry through the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal and the Hong Kong International Convention for the Safe and Environmentally Sound Recycling of Ships. The Opinion emphasised that from an emissions perspective, transboundary harm is being tackled through regulations aiming to gradually reduce the annual average GHG intensity of energy used by ships trading in the EU and increase the demand for and consistent use of renewable and low-carbon fuels.

The Tribunal’s comments on transboundary harm are particularly important findings for the maritime transport industry, as they clarify that states’ ”new” obligations will not infringe any of the existing rights and obligations under UNCLOS. This should provide a layer of comfort to states regarding their current status under UNCLOS, and should prevent occasions of unjustifiable interference between states when taking measures to mitigate marine pollution.

6. States are obliged to monitor and publicize the environmental risks of pollution

The Tribunal further found that states are required by Articles 204-206 UNCLOS to monitor the risks and effects of marine pollution, conduct environmental impact assessments for any activity which “may cause substantial pollution to the environment or significant and harmful changes thereto through anthropogenic GHG emissions”, and publish reports on the findings[35].

The consequences of states monitoring vessels’ pollution were already being felt before the Opinion was published, for example, cruise ships were being refused port calls in New Zealand and Australia over biofouling (i.e., carrying harmful marine organisms into local ecosystems on the hull of the ship)[36]. The Opinion may spur more states into action, consequently requiring shipowners and managers to consider the impact their polluting activities may have not only on the environment, but also on their commercial operations.

Turning to the second, broader question posed in the Request, regarding states’ obligations to protect and preserve the marine environment from the effects of marine pollution caused by anthropogenic GHG emissions, including ocean warming, sea level rise, and ocean acidification, the Tribunal found that states are legally obliged to protect and preserve the marine environment.

7. States are legally obliged to protect and preserve the marine environment

The Opinion states that states’ obligation under Article 192 UNCLOS to protect and preserve the marine environment extends to “any form of degradation of the marine environment, including climate change impacts, such as ocean warming and sea level rise”[37]. This obligation entails maintaining a healthy and balanced marine ecosystem and is an obligation of “dual significance” in that it promotes the conservation and resilience of marine ecosystems while also mitigating climate change[38].

Further, the Tribunal found that where a marine environment has already been degraded, states’ obligation under Article 192 may require restoring those habitats and ecosystem[39]. This, too, is a stringent obligation of due diligence, given the high risks of serious and irreversible harm to the marine environment from climate change impacts and ocean acidification.

The Tribunal clarified that this obligation necessarily involves states implementing measures to mitigate climate change (i.e. reducing or sequestering GHG emissions); to implement climate adaptation and resilience measures (e.g. restoring mangrove forests); and to protect and prevent further harm to marine ecosystems that sequester carbon dioxide[40].

Further, the Tribunal found that states have an obligation under Article 194(5) of UNCLOS to protect and preserve “rare or fragile ecosystems as well as the habitat of depleted, threatened or endangered species and other forms of marine life”[41]. An example of a fragile ecosystem are ice-covered areas governed by Article 234 UNCLOS.

In fact, this obligation is not too dissimilar to the Convention for the Protection of the Mediterranean Sea Against Pollution (Barcelona Convention), which requires that signatories take all appropriate measures “to protect and preserve biological diversity, rare or fragile ecosystems, as well as species of wild fauna and flora which are rare, depleted, threatened or endangered and their habitats, in the area to which this Convention applies.”[42]. Therefore, when it comes to operators in the Mediterranean, the Opinion does not lay down new rules in this respect, but rather re-emphasises existing ones.

8. Global and regional cooperation

Finally, the Tribunal found that States are required to cooperate directly, continuously, meaningfully, and in good faith to meet these obligations[43]. States must cooperate to formulate rules, standards and recommended practices and procedures, based on the best available science, to mitigate marine pollution from GHG emissions, and establish scientific criteria, promote studies, undertake research, and exchange information including data on marine pollution[44].

Parallel efforts to clarify states’ obligations regarding climate change

The Opinion is one of several ongoing efforts to clarify states’ obligations regarding climate change in courts and tribunals around the world. As discussed above, advisory opinions are expected from the Inter-American Court of Human Rights (which had its oral hearings between 23 and 25 April 2024) later this year, with an opinion of the International Court of Justice, the highest court of the United Nations, to follow in 2025.

In April 2024, the European Court of Human Rights found that states have a legal obligation to protect their citizens from the extreme adverse impacts of climate change, and that Switzerland had violated the human rights (specifically, the right to respect for private and family life) of its citizens by failing to do so. Shortly afterwards, the Indian Supreme Court declared that citizens have a constitutional right to “protection against the adverse impacts of climate change”. On 21 May 2024, the South Korean Supreme Court heard a combined claim asserting that South Korea’s national emissions reductions plans are insufficient and violate the plaintiffs’ constitutional rights, including the right to a healthy environment.

Although these efforts target governments’ obligations regarding climate change, they will likely impact national legislation and policy, and, therefore, have a knock-on effect on companies and financial institutions that materially depend on or impact oceans and marine systems.

Closing commentary on the marine sector

The Tribunal’s Opinion is expected to have an impact on commercial shipping, albeit not a direct one, given the nature of ITLOS and its lack of direct enforcement. Already, maritime industry stakeholders are investing in various initiatives such as the green shipping corridors, setting up routes where carbon-neutral ships start using carbon neutral fuels earlier than required under existing rules and initiatives, thereby minimising the harmful effects of marine pollution. It should be noted that green shipping corridors form an important playground for testing and scaling new fuel solutions and technologies targeting decarbonisation and also digitalisation. For this and other initiatives to bear fruit, a combined effort of private operators and public authorities will be required.