Global environmental regulation of offshore energy production: Searching for legal standards in ocean governance

synergies among envi‐ instruments and the interaction of non‐binding instruments with binding rules the legal gaps the interna‐ legal standards for the regulation of this sensitive sector.

The international environmental regulation of all types of energy generation activities at sea is first and foremost anchored to the United Nations Convention on the Law of the Sea (UNCLOS). However, both at the global and regional levels, UNCLOS is complemented by an array of evolving environmental agreements. These normative developments can put flesh on the bare bones of the general (due diligence) obligation of States to protect the marine environment with regard to offshore energy activities. Parallel to binding obligations under environmental agreements, there are a variety of non-binding instruments, which can also play a key role in enriching the content of prevention obligations. Depending on their source, their form and the procedure by which they are adopted, these non-binding pronouncements may become legally relevant as interpretative guidance or standard of proof that a State has exercised due diligence. In this context, the article posits that synergies among environmental instruments and the interaction of non-binding instruments with binding rules of international law can fill the current legal gaps and strengthen the international legal standards for the regulation of this environmentally sensitive sector. offshore energy installations, hydrocarbon extraction activities pose grave threats to the oceans. 4 By comparison, marine renewable energy generation had been regarded as benign to the marine environment. 5 Nonetheless, the projected expansion of the marine renewable industry has recently drawn the attention of scientists concerning their potential effects, including noise pollution, the alteration of electromagnetic fields, changes in water quality and disturbance of the habitat structure of fish, mammals and birds (the latter only when it comes to offshore wind farms) or even their direct mortality. 6 Unsurprisingly, there is no single international agreement regulating the environmental externalities of offshore energy activities. 7 The United Nations Convention on the Law of the Sea (UNCLOS), serving as the 'constitution of the oceans', 8 sets forth the jurisdictional framework and spells out the general environmental duties of States, among others, regarding offshore energy production.
UNCLOS provides the obligation to exercise due diligence in preventing, reducing or controlling marine environmental pollution from offshore energy activities within their jurisdiction. 9 However, UNCLOS is complemented by an array of global and regional environmental treaties. These agreements can put flesh on the bare bones of the seemingly evasive due diligence obligation to protect the marine environment from risks related to offshore energy production activities. 10 In other words, relevant environmental obligations can inform and shape the standard of due diligence. 11 Since failure to show due diligence in preventing significant marine environmental harm can give rise to State responsibility, it is indispensable for States to determine the normative content of that standard. Thus, defining the normative content of the international obligation to prevent marine environmental harm in the context of marine energy generation activities is essential for States to evaluate whether their conduct is adequate to meet their international duties.
Moreover, legal clarity regarding the environmental obligations of States and the standards applicable in offshore energy generation activities is equally important for industry. In particular, investors should be fully aware of the legal framework within which their offshore energy projects operate to estimate regulatory risks during the long life cycle of their capital-intensive investments. 12 In addition, when it comes to the international environmental regulation of offshore energy generation, one needs to acknowledge that, besides States, there are a multiplicity of non-State actors, who also contribute to shaping and implementing the relevant legal framework. 13  This article considers the production of offshore energy to cover the generation of all sources of energy in marine areas, including both the exploitation of fossil fuels (offshore oil and gas) and harnessing renewable ocean energy. 8 As suggested by Tommy Koh, president of the third UN Conference on the Law of the conventions of global remit interact and inform the prevention obligations under UNCLOS. Section 4 examines the relevance of non-binding instruments in defining the standard of due diligence. The section further explores the interactions between the international rules and non-binding instruments relevant to the offshore energy sector, as such instruments can offer guidance in the interpretation of the standard of due diligence. The article aims to assess their potential to complement and strengthen the treaty-based environmental regulation of offshore energy production. The hypothesis is that synergies among environmental instruments and the interaction of non-binding instruments with binding rules of international law can enhance the normatively modest legal framework.

| Prevention obligations under UNCLOS and the normative contours of due diligence
First and foremost, the international environmental regulation of all types of offshore energy generation activities is anchored to UNCLOS. 16 Coastal States are under an obligation to use all means at their disposal 'to prevent, reduce and control pollution of the marine environment arising from or in connection with seabed activities subject to their jurisdiction and from artificial islands, installations and structures under their jurisdiction'. 17 Their duty to prevent pollution does not only entail the adoption of the necessary laws and regulations but, at the same time, they must show a certain degree of vigilance in their implementation and ensure that the activities of private actors engaging in such activities within their jurisdiction will not cause significant harm to the marine environment. 18 States are expected to endeavour to prevent pollution, but it cannot be guaranteed that harm will not eventually take place. 19 In other words, this obligation does not require States to achieve a certain result;‧it is merely an obligation of conduct. Still, the obligation to take all appropriate measures to prevent environmental harm requires States to meet the standard of due diligence. 20 The standard of due diligence reflects the conduct to be expected by good government, as it requires the adoption of laws and measures at the domestic level applicable to public and private entities, which can prevent or limit transboundary environmental harm. 21 Within the normative contours of the obligation of prevention, the standard of due diligence is measured against both the substantive and the procedural extensions of this primary obligation. 22 The State is expected to adopt reasonable measures and safeguard their effective implementation and simultaneously to cooperate with the other potentially affected States. In this context, the procedural environmental obligations of the State to cooperate in good faith in mitigating transboundary environmental harm (by means of conducting an environmental impact assessment (EIA), notification, consultation and monitoring the effects of hazardous activities on the environment) 23 remain independent, but in parallel they are considered as the basic objective elements of the prevention obligation. 24 This connection between due diligence and primary environmental obligations seems to be confirmed in the circumstances of the specific case. The flexibility of the due diligence benchmark allows the content of the obligation to adjust in relation to the risks that are posed by an activity, as a higher standard of care is expected for riskier activities. 29 In the law of the sea, due diligence can have a strongly technical nature, 'capable of measurement in terms of technical and scientific standards of behaviour that are commonly accepted by States'. 30 It is necessary for States to consider contemporary technological advancements, 31 because developments in scientific awareness regarding the risks posed by specific activities may enhance the level of due diligence required. 32 In addition, it was noted that the environmental measures adopted by States may not remain perpetually the most appropriate, but States have to review them regularly to comply with their duty to exercise due diligence in the face of new developments. 33

| The global international legal framework beyond UNCLOS
Although UNCLOS mandates States to develop further international environmental instruments, 34 limited progress has been made to adopt elaborate international rules and standards for offshore en- offshore energy installations are required to formulate oil pollution emergency plans 45 and there is an obligation to immediately report any discharge of oil. 46 These more elaborate provisions, which require specific implementation measures, attach substantive content to the prevention obligation of States. By imposing more precise obligations, they restrict the wide discretion that States have in regulating the operation of offshore energy installations. 47

| The contextual implications of marine biodiversity-related instruments
Biodiversity-related conventions have further contextual implications for the regulation of offshore energy activities. While they do not contain explicit rules for offshore energy activities, they create obligations for States to adopt conservation management measures to protect marine areas or species. Such conservation measures can indirectly influence the regulation of offshore energy activities.
These instruments aim to restrict, limit or even prohibit hazardous activities to protect biodiversity, and thus become relevant to the planning, siting and operation of offshore energy generation projects. 48 For instance, the 1992 Convention on Biological Diversity (CBD) 49 requires its parties to take, as far as possible and appropriate, action to halt the destruction of species, habitats and ecosystems. 50 It provides that States shall 'identify processes and categories of activities which have or are likely to have significant adverse impacts on the conservation or sustainable use of biological diversity', and when these effects are determined, they shall 'regulate and manage' such activities. 51 Similarly, the Convention on the to these environmental agreements and reports by their Scientific Committees, have explicitly addressed environmental aspects of marine renewables. 56 Among others, these resolutions urge contracting States to conduct EIAs prior to authorizing offshore energy activities and recommend the use of best environmental practices (BEP) and best available techniques (BAT).

| The vague nature of the relevant environmental obligations
The global international legal framework regulating some aspects of In that sense, the vague wording of their texts reflects the compromises struck during the lawmaking process. For instance, even though the CBD enjoys almost universal acceptance, most of its obligations 45 OPRC (n 39) art 3(2). 46 ibid art 4(1)(b)(ii). 47 The OPRC also requires specific tools and equipment to be developed to coordinate the response to a pollution incident; OPRC (n 39) art 6(2).  are phrased in vague terms and are further watered down by qualifiers, such as 'as far as possible and as appropriate'. 57 Therefore, the global instruments themselves seem to fail to offer concrete environmental standards for offshore energy production activities.

| NORMATIVE INTER AC TI ON S B E T WEEN UN CLOS AND MULTIL ATER AL ENVIRONMENTAL AG REEMENTS: UPDATING THE PRE VENTI ON OB LI G ATI ON FOR OFFS HORE ENERGY PRODUC TION
Notwithstanding the weaknesses of the global legal framework, 58 the interplay between UNCLOS and other environmental agreements might lead the way forward. Importantly, the drafters of UNCLOS did not envisage its environmental obligations to operate in clinical isolation from normative developments in international environmental law. To the contrary, the Convention incorporates different mechanisms to adapt to legal, environmental and technological developments. In that respect, it could be claimed that UNCLOS is the 'mother' of all normative interactions with 'external' normative developments. This section examines legal mechanisms that enable the interaction of external environmental rules with the prevention obligations under UNCLOS, and that may result in better defining the normative contours of the due diligence standard. has been interpreted as requiring that those rules are generally accepted in State practice. 86 According to Oxman, in view of the strategic interest of States in offshore resources, the obligation of the coastal State to accept a restriction of its sovereign right over its marine natural resources in the form of environmental rules and standards, which it has not explicitly consented to, shall be only interpreted as covering only those 'truly international by virtue of their widespread (that is general) acceptance'. 87

| Normative interactions through interpretation
There seems to be some convergence among scholars that certain IMO conventions, such as MARPOL, the International Convention for the Safety of Life at Sea and the London Dumping Convention, contain international rules, which enjoy wide acceptance by States and thus qualify as international rules in the meaning of UNCLOS. 88 Arguably, at the time of adoption of UNCLOS, the drafters had these agreements in mind when they referred to generally accepted rules. 89 As was discussed, these agreements include some rules which are applicable to offshore energy production activities. Besides the IMO agreements, it seems that some biodiversity-related agreements have reached the same level of acceptance and can similarly be considered as rules in- ascertained. 104 In other words, the precautionary principle extends the rule of prevention to apply at a timescale where there is no certain scientific proof meeting the threshold of risk that triggers the rule of prevention. 105 In this regard, precaution and prevention cannot be easily separated. 106 The precautionary principle provides another example of how different environmental norms can enhance the standard of due diligence. Thus, as the obligation to prevent harm to the marine environment is further enhanced by developments in international environmental law, the discretion of States in determining their duty to regulate is commensurately restrained.

| NON -B INDING INS TRUMENTS AND THEIR RELE VAN CE IN S E T TING ENVIRONMENTAL S TANDARDS FOR OFFS HORE ENERGY AC TIVITIE S
The present inquiry into normative developments that affect the standard of prevention under UNCLOS cannot ignore the parallel existence of a variety of non-binding, but legally relevant instruments. Non-binding instruments can differ with respect to the norms contained, the actors that develop them and their addressees: 109 memoranda of understanding among different agreements, declarations of environmental principles and action plans adopted at international conferences, codes of conduct, technical standards and recommendations adopted by international organizations, and ocean corporate responsibility instruments are just a few examples.
Next to their precursory role in the creation of rules of international environmental law, 110 non-binding instruments can also impact on the standard of environmental protection by influencing UNCLOS through interpretation. As a detailed analysis of all the relevant nonbinding instruments goes beyond the scope of this article, this section focuses on developments by international organizations, treaty bodies to environmental agreements and self-regulatory initiatives by the offshore energy industry.

| Non-binding instruments by international organizations
When it comes to standards, one should first acknowledge the nonbinding instruments related to offshore energy production activities those international standards. It seems that UNCLOS attaches some importance to the forum in which those standards are promulgated.
Another implicit requirement is that their content should be able to inform the laws and regulations adopted by States. 116 Therefore, their normative nature and the language used should provide some guidance on whether these were drafted with the aspiration of becoming generally accepted international standards.
In that respect, it seems that the above-mentioned instruments are not aimed at providing standards that can clarify the content of the duty of States to regulate the environmental externalities of offshore energy production activities. For example, the 2009 MODU Code is only relevant to the construction and equipment of offshore installations, and its aim is to ensure safety for these de- With respect to environmental standards, it is perhaps worth mentioning the IMO guidelines clarifying the application of certain provisions of the MARPOL Annex I with regard to FPSOs and FSUs. 122 Similarly, in 2010 the MEPC issued an instrument to guide States on the development of regulations on safety, pollution prevention and security of FPSOs and FSUs. 123 Again, these instruments fall short of providing international standards for the purpose of the rule of reference, as they just reiterate the obligations under IMO agreements. It is however noticeable that those instruments make explicit references to industry-produced guidelines and recognize their contribution to pollution prevention from FPSOs and FSUs. 124

| Non-binding resolutions and reports by treaty bodies to environmental agreements
Most of the environmental obligations applicable to offshore energy generation activities are evolving over time through resolutions and decisions of treaty bodies. Under many environmental agreements, the COP is competent to decide upon binding understandings of the agreement's provisions. 125 However, many decisions and resolutions by treaty bodies, such as scientific committees, are not legally binding and their normative value as interpretative tools cannot be taken for granted. A typical example is the practice of the COP to the CBD, which has preferred in many instances to use non-binding decisions to provide recommendations to the parties on the measures they need to take to comply with their obligations. 126 Treaty bodies to the biodiversity-related agreements under consideration have produced guidance on the conduct of EIAs and SEAs, which are important for offshore energy projects. 127 These guidelines stress the importance of applying a precautionary approach in decision making when there is scientific uncertainty regarding the risk to marine biodiversity. 128 Furthermore, they recommend including noise emissions in the screening criteria for determining the need for EIA, 129 and they recall the importance of continuous monitoring of the impact of the planned activities. Similarly, the guidance related to activities in the energy sector, including tidal and wave energy projects, adopted by the COP to the Ramsar Convention 130 recommends the meticulous application of EIAs and SEAs to energy production activities that may significantly affect the ecological character of wetlands. It further urges the need for adoption of a precautionary approach. 131 Likewise, the CMS COP has adopted resolutions on the prevention and mitigation of impacts of marine renewable energy devices on migratory species. 132 116 Oxman (n 85) 148.

| Non-binding instruments as best available techniques and best environmental practices
Another legal mechanism which enables non-binding instruments to inform the due diligence standard are the concepts of BAT and BEP. In the words of the ICJ, the standard of due diligence in preventing environmental harm requires that these measures be 'in accordance with applicable international agreements and in keeping, where relevant, with the guidelines and recommendations of international technical bodies'. 155 In Pulp Mills, Uruguay, aiming to prove that it complied with its obligation of due diligence, argued that the technology involved was the most appropriate to prevent pollution, because it was state-of-the-art waste cleansing equipment, which had been perceived by both the United States and the European Union as the best available technology. 156 The Court ac- strategies'. 162 Even though these definitions are provided by a regional agreement, the fact that the obligation to follow BEP and BAT is found in the majority of regional instruments related to offshore energy activities could mean that the obligation has acquired the status of international rule for the purpose of Article 208(3) UNCLOS. 163 Despite the various critiques on the malleable character of non-binding environmental standards, 164 the obligation to apply BEP and BAT enables the standard of due diligence to evolve as technology develops over time. 165 It seems that it would be difficult for a State to claim compliance with the due diligence standard in case it has failed to apply BAT and BEP. Even if one denies their normative role in shaping the content of the due diligence standard, they remain important proof that States have taken all necessary and appropriate measures to prevent marine environmental harm.
In view of the different legal mechanisms which justify considering non-binding instruments by treaty bodies for the purpose of defining due diligence, the normative value attached to resolutions not supported by all States does not pose a threat to the sovereignty of those parties that did not acquiesce to their content, but allows for a more nuanced and sophisticated understanding of sovereignty. 166 Those States have consented to be bound by an environmental agreement, which is expected to evolve following scientific and technological developments. By becoming parties to such agreements, they have consented to self-restrain their sovereign regulatory discretion in the light of such future normative developments.
Particularly, they have undertaken to delegate certain decision-making power to specialized treaty bodies. Depending on their institutional source and the form and procedure by which they are adopted, these legally non-binding pronouncements may become relevant as interpretative guidance or standard of proof that a State has exercised due diligence. Therefore, even if those resolutions are not legally binding, they can be legally relevant, and States might have an obligation to take them into account in their decision-making process. This restriction does not necessarily impair sovereignty. It rather reinforces the concept of sovereignty, because it is a self-imposed restriction. The example of Odysseus in Homer's Odyssey illustrates how self-restriction is in fact an expression of sovereignty.
According to Homer, Odysseus decided to tie himself to the mast of his ship when it approached the legendary Sirens. His decision to restrain himself allowed him to listen to the song of the Sirens while at the same time safeguarding that he would not be hypnotized and jump into the sea to his death. Similarly, it is the consent of States, grounded in their sovereignty, that makes the obligations binding upon them and gives competence to the institutional machinery under treaties to adopt decisions to further elaborate the content of the obligations. If States do not wish to be in any way influenced by these subsequent developments, they maintain the sovereign right to opt out or withdraw from the treaty.

| The role of industry standards
From an international law perspective, perhaps the most problematic category of non-binding instruments for defining due diligence are those produced by the offshore energy industry. States have an obligation to exercise due diligence in adopting laws and regulations to prevent, control or minimize pollution from offshore energy activities. Nonetheless, the standard of due diligence allows States wide discretion in complying with their duty to regulate offshore energy production. In this context, many domestic regulatory regimes do not prescribe specific technical and technological requirements for the operation of offshore energy production activities, but instead they adopt a goal-based or performance-based approach. 167 Goal-or performance-based regulation sets the goals or performance objectives to be achieved and allows companies to identify the appropriate means to reach them. 168 The underlying idea is that States are unlikely to constantly keep up to date with the latest technology and cannot take advantage of the developments as effectively as the private sector. 169 This regulatory approach enables the offshore industry to have a strong say in developing its own operational standards. 170  Unsurprisingly, UNCLOS does not make any reference to standards which are produced by private actors. That could prima facie mean that standards produced by the offshore energy industry are not legally relevant in defining the standard of due diligence.
According to UNCLOS, international standards need to be generally accepted by States for them to influence the content of their duty to regulate. However, States that opt for the goal-based regulation seem to endorse the standards produced by the offshore energy industry, so long as they can reach the goals set by the domestic regulators. It is questionable whether that means that States delegate regulatory authority to those private actors.
Moreover, it is rather debatable that the generalized practice by the offshore energy industry reflects implicit State practice. 173 Therefore, the general acceptance of self-regulatory standards by the industry, even if private practice is found to be consistent around the world, would not necessarily alter the non-binding nature of private standards. Much less, these standards cannot be considered as informing the international obligations of States. It is also unlikely that private environmental standards can be considered as international standards for the rule of reference in Article 208(3) UNCLOS simply because they are referred to in guidelines produced by intergovernmental organizations. As was noted, IMO guidelines contain explicit references to standards for the prevention of pollution created by the offshore industry. 174 The endorsement of such standards in guidelines of the organization could possibly render them binding for parties to the IMO.
However, that does not necessarily mean that they also acquire the status of international standards to be incorporated in UNCLOS through its rules of reference. Even if one accepts that particular IMO guidelines have become binding on all parties to UNCLOS as international standards under Article 208(3), the mere reference therein to the standards of the offshore industry cannot grant the latter the same generally binding nature. That is primarily because these standards are developed by industry, which cannot be considered as 'competent international organization' within the meaning of Article 208. 175 Still, the input of the offshore energy industry in adopting international standards and best practices for the environmental regulation of offshore energy production seems indispensable. 176 Guidelines and technical standards can operate as models in adapting the existing legal framework to new circumstances. 177 Co-regulation as a means for interaction between international environmental law and private standards could perhaps generate solutions for the environmental problems related to offshore energy production. This is confirmed by international initiatives for cooperation between States, international organizations and representatives of the industry. For example, the Global Marine Environmental Protection Initiative launched by the Group of 20 is an important development for the promotion and sharing of best industry environmental practices. 178 It is an outstanding example of public-private cooperation that brings together the expertise of States, international organizations (the IMO, the IEA and the Organization of the Petroleum Exporting Countries), associations of domestic regulators (the European Union Offshore Oil and Gas Authorities Group, the International Regulators' Forum) and professional associations (OGP, IPIECA). The initiative aims to 'share best practices to protect the marine environment, to prevent accidents related to offshore exploration and development, as well as marine transportation, and to deal with their consequences'. 179 Nonetheless, despite the importance of such initiatives in sharing best practices, private environmental standards can only be incorporated by reference and become internationally binding if they are met with general acceptance by States. Such State practice, for instance, could be reflected in the consistent incorporation of private environmental standards in State contracts with operators of offshore energy activities. 180

| CON CLUS IONS
The concept of due diligence holds a special significance as a standard for the duty of States to regulate offshore energy production. The vagueness of the due diligence standard in the context of the obligation to prevent pollution from offshore energy production activities has been criticized for moderating the normative guidance regarding the required standard of care. Yet, it is that same feature which equips it with the required flexibility to adapt to new environmental circumstances and different levels of risk. 181 Due to its variable and evolutionary nature, due diligence can operate as an important integrative mechanism beyond the rules of treaty interpretation. The various environmental agreements that have implications for offshore energy production activities could provide the parameters for further elucidation of the standard of due diligence. 182 These obligations of States enhance the due diligence standard by attaching more precise normative substance to it.

Environmental agreements include a wealth of benchmarks for
States to determine what is the standard of care that needs to be exercised to prevent or minimize such marine environmental harm. Take for example the unqualified prohibition of 'taking' of certain protected species (migratory species under Annex I of the CMS Convention) or restriction of certain activities in protected areas (designated under the CBD, or wetlands listed under the Ramsar Convention). These more precise obligations call into question the breadth of discretion enjoyed by States in complying with their duty to regulate offshore energy activities. The normative layers accumulated in the obligations to protect and preserve the marine environment under UNCLOS illustrate how interactions through interpretation may have a normative standards found in relevant norms of international environmental law, the general obligations under UNCLOS get shaped. 183 Still, the importance of adopting more sophisticated rules on the environmental regulation of offshore energy production activities cannot be overstated, bearing in mind the technical expertise the regulation of such activities require. 184 In addition, non-binding instruments have the potential to strengthen the level of due diligence that is required by States in implementing their duty to protect and preserve the marine environment. Due diligence calls for States to keep abreast with 'current specifications and standards'. 185 Specifically, non-binding instruments have the advantage of being easily adaptable to the rapid scientific and technological developments in the offshore energy sector. Primarily as interpretative guidance, they can be influential in restraining the wide discretion that States enjoy in choosing measures to protect the marine environment. Of course, the normative impact of non-binding instruments largely depends on their institutional source and the form and procedure by which they are adopted. These standards can act as a benchmark against which to determine whether the relevant international obligations have been met, as they can provide normative guidance and substantiate existing binding obligations. Even when non-binding instruments cannot be considered as influencing environmental obligations through defining the due diligence standard, compliance with their content may be referred to as proof that States have been diligent. Therefore, the best outcome in identifying international standards for the environmental regulation of offshore energy production can be achieved through the interaction between binding and non-binding international instruments. 186  How to cite this article: Giannopoulos N. Global environmental regulation of offshore energy production:

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Searching for legal standards in ocean governance. RECIEL.