Provisions of Part xII of UNCLOS on enforcement of IMO GHG rules (MARPOL Annex VI)
This page lays out how the provisions found in Part XII of UNCLOS for protection of the environment, focusing on articles 217, 218, 220 and 228, can form the basis for effective enforcement of IMO rules on GHG found in MARPOL Annex VI (EEXI, EEDI, CII)) and in a fuel standard as set out in the IMO’s GHG Strategy)
Art. 92 of UNCLOS reiterates a basic principle of the law of the sea, often referred to as the flag state principle. This principle stipulates that flag States have an unimpeached jurisdiction on the high seas over vessels flying their flag. This can, nonetheless, present a problem if the flag State is reluctant to probably enforce violations of international (IMO) regulations.
The undisputed nature of the flag State’s jurisdiction might have certain merits when dealing with high seas enforcement of different international regulations on safety, navigation, manning or labor conditions. However, UNCLOS provides in its twelfth chapter (Part XII) some exceptional possibilities for non-flag States to enforce international environmental legislation on the high seas if a flag State fails do so.
The book (“Enforcing International Maritime Legislation on Air Pollution through UNCLOS”) lays out that some of these exceptions to the flag State principle, found in Part XII of UNCLOS, provide the necessary jurisdiction to enable port States to impose fines that adequately sanction violations of international (IMO) emission regulations on GHG and sulphur, also for violations that occur on the high seas.
Initially, it should be stated that the term pollution of the marine environment under UNCLOS covers pollution which inter alia can present “…hazards to human health…” according to the definition in article 1 (1) (4) of UNCLOS.
This means that the enforcement of GHG (and SOx, NOx, ODS’ and VOCs) in MARPOL Annex VI, which main objective is to improve the conditions for human health by reducing air pollution, is covered by the Part XII regulations. This assumption also been confirmed by IMO’s Legal Committee and ITLOS in Advisory opinion 31 of 24 May 2024 regarding impact of Climate Change on Small Island States which clearly establishes that the term “Pollution of the marine environment” in art. 1 (1) (4) of UNCLOS – and thus covering the scope of Part XII – includes pollution by GHG emissions.
It should be noted that the relevant special provisions of Part XII of UNCLOS confer special obligations and rights for enforcing environmental regulations. The special enforcement and notification obligations for flag States stipulated in article 217 of UNCLOS is examined, followed by the extraterritorial right for port States to enforce on the high seas pursuant to article 218
This is primarily based on an interpretation of the discharge-term used in article 218 of UNCLOS to encompass emissions. An interpretation which applies the general recognized principles of international law codified in article 31-32 in the Vienna Convention on the Law of Treaties (VCLT) supported by references to how the term is defined and used in other international maritime regulations, for example in the MARPOL Convention itself and in Annex VI of this convention (MARPOL).
Other conditions must be met to have art. 218 apply, which the book describes in full.
Finally, article 228 (1) of UNCLOS clarifies how the overlapping high-seas jurisdiction between flag and port States in article 217 vs. 218 is resolved.
In short, article 228 (1) has a main rule which allows the flag State to, within six months, request suspension of a port State’s initiated proceedings. The flag State must subsequently prove the instigation of corresponding charges and effective enforcement to the port State by sending a full dossier of the case and records of the proceedings. Otherwise, the port State can resume the suspended proceedings.
Further, a port State can deny a request for suspension in accordance with the second exception of article 228.1 if a flag State repeatedly has disregarded its article 217-obligations to effectively enforce violations of an international regulation, for example MARPOL Annex VI and/or to inform hereof.
For more information on how the above is laid out in the the different chapters in the book “Enforcing International Maritime Legislation through UNCLOS” see here: Book About UNCLOS