Symposium on the ICJ Climate Change Advisory Opinion: What it Means for Seabed Mining for the Green Energy Transition (Part II)

[Digvijay Rewatkar is an LLM candidate at Harvard Law School and an international lawyer with seven years of experience. The views expressed here are those of the author and do not reflect the views of his affiliations. This post was drafted before he commenced his course at Harvard Law School.]

Fortunately or unfortunately, depending on the readers’ vantage point, the seabed mining industry is trying to establish itself as a complementary and, perhaps, an alternative source of minerals required for the green energy transition. To postulate the scale of resources, according to the International Seabed Authority (ISA) mining across 4.5 million square kilometers of the Clarion-Clipperton Zone – an area encompassing 1.5 percent of the world’s abyssal plains – could yield approximately 34 billion wet metric tons of nodules containing 6 billion tons of manganese, 270 million tons of nickel, 234 million tons of copper, and 46 million tons of cobalt. The minerals outlined above are also serendipitously essential for the green energy transition. As the battery storage requirements grows by 11 times between 2020 and 2040, overall demand for minerals in the base case grows by 33 times. Further, the mineral demand will continue to outpace battery demand and renewable growth, as the market share of mineral-intensive batteries (NMC chemistries) increases. For instance, the International Energy Agency (IEA) projects that the demand for copper could increase by 28 times, cobalt by 70 percent, nickel by 140 percent, manganese by 92 times, and rare earth elements by 37 percent by 2040.

As Part I discussed, the steep rise in the demand for minerals as we transition away from fossil fuels is likely to be initially offset through the expansion in land-based mining. Land-based mining comes with its own set of risks of GHG emissions, particularly through widespread deforestation in tropical areas of Brazil, Indonesia, the Democratic Republic of Congo, and Myanmar. Further, with the growing demand for these critical minerals, the current land-based mining industry is likely to experience hurdles in meeting these demands in the future, as lower grades and more challenging environmental constraints make many operations unfeasible. With lower grade of the land-based ores, the carbon intensity of the processing increases, leading to increased GHG emissions. It is in this context that seabed resources might prove to be essential as they would offer a higher grade of polymetallic ores, leading to more metal per ton of ore processed with less GHG emissions.

The principles, obligations, and responsibilities enunciated in the Climate Change AO would in pari materia also apply to the seabed mining industry. However, almost all of these obligations are already subsumed through the draft exploitation regulations being negotiated at the ISA – the custodian of seabed resources in the Area (article 137, UNCLOS), and a previous advisory opinion of the Seabed Disputes Chamber (SDC) of the International Tribunal of the Law of the Sea (ITLOS).

Legal Obligations in the Context of Seabed Mining

Seabed mining is unusual in the history of extractive activities because, for the first time, scientific studies on its impacts have preceded the act of extraction. This has led to significant advancement in the understanding of deep-sea ecosystems and geology, albeit, like most things in life, our ignorance remains larger than our knowledge – thus, the oft-repeated phrase ‘we just don’t know enough about the deep sea’. Owing to this, SDC Advisory Opinion has already called for the exercise of stringent due diligence in conducting ‘activities in the Area’ in its advisory opinion on Responsibilities and obligations of States with respect to activities in the Area (SDC AO). 

“[…] “due diligence” is a variable concept. It may change over time as measures considered sufficiently diligent at a certain moment may become not diligent enough in light, for instance, of new scientific or technological knowledge. It may also change in relation to the risks involved in the activity. As regards activities in the Area, it seems reasonable to state that prospecting is, generally speaking, less risky than exploration activities which, in turn, entail less risk than exploitation. Moreover, activities in the Area concerning different kinds of minerals, for example, polymetallic nodules on the one hand and polymetallic sulphides or cobalt rich ferromanganese crusts on the other, may require different standards of diligence. The standard of due diligence has to be more severe for the riskier activities.” (para. 117)

In addition, UNCLOS as a directly applicable relevant law contains the general obligation for the protection of the marine environment set out in Art. 192 of the UNCLOS, specifically Art. 145, calls for necessary measures to be taken for the effective protection of the marine environment from seabed mining extractive activities. Additionally, Art. 209 calls on states to adopt international rules and regulations for the prevention, reduction, and control of pollution, and Annex III Art. 17(f) calls on the ISA to draw rules, regulations and procedures to secure effective protection of the marine environment from harmful effects directly resulting from activities in the Area. 

Further, the SDC AO set out clear due diligence (para. 117-120) and direct obligations (para. 121-140), including the obligation to implement the precautionary approach (para. 135), prevention of significant harm to the marine environment, performing environmental impact assessments (EIAs) (para.150), and clearly established the rules concerning responsibility (para. 170-174), causal link for damage (para. 184) and liability (para. 206-207). It could therefore be argued that there is now parity in terms of regulatory obligations between seabed mining and land-based mining, which had remained discrete and fragmented for the longest time in the case of the latter.

Implementing the Due Diligence Obligation vis-à-vis Seabed Mining

The critical issue within the seabed mining industry is that the contractors may, in some cases, be private actors sponsored by the states (Art. 153(2)(b), UNCLOS). The key issue in this regard, addressed by the ICJ AO on climate change, concerns the due diligence obligation of the state and the attribution of the conduct of private actors under the jurisdiction and control of the state. This is apparent when the International Court of Justice says, “a State may be responsible where, for example, it has failed to exercise due diligence by not taking the necessary regulatory and legislative measures to limit the quantity of emissions caused by private actors under its jurisdiction.” (para. 428). However, this remains a non-issue in the case of seabed mining owing to the particular structure of the contractual regime established under Part XI of the UNCLOS, and has already been clarified by the SDC when it says, that the responsibility of the sponsoring states arises not from a failure of a private actor but rather from its own failure to carry out its own responsibilities; in other words, implementing the international rules, regulations and procedures with the appropriate due diligence standard (para. 182, SDC AO).

As the SDC AO recognizes, the standard of due diligence can be achieved through not only the full spectrum implementation of rules, regulations, and procedures but, may also be achieved through the implementation of best available techniques (BAT) (also, the implementation of the precautionary approach/ principle and prevention of significant harm to the environment).  At the outset, it is essential to acknowledge that the concept of ‘Best Available’ is inherently relative and involves a comparative assessment. This was the question before the arbitral tribunal in the UK-Sandeel case, where the tribunal interpreted, “best” [to] be read in the context of “available [technology]” and not in the absolute sense of the best possible.’ (para. 489) Therefore, the technology used must be sensitive to the deep-sea benthic environment and adhere to the precautionary approach. According to the arbitral tribunal, it follows that, ‘[available technology] is not limited to [one] that exists at the time […], but extends to [technology] which could reasonably have been [used] at that point in time.’ (para. 491) Therefore, seabed mining contractors must make a reasonable degree of effort to obtain the BAT at the time the mining project is under consideration. 

From the vantage point of a project opponent, it may be argued that the technology proposed for seabed mining is not the best available, either because superior technology exists or the current technology is fundamentally flawed. To interpret the view of the arbitral tribunal in the UK-Sandeel case, it does not require the opponent to identify a better technology. Instead, the opponent must demonstrate that the significant flaws in the technology prevent it from meeting the standard of BAT (para. 494). Given this understanding of “best available,” it is crucial to evaluate how BAT has been considered in international law. 

The draft exploitation regulations (see Schedule, Use of terms and scope at p. 218) borrows the definition of BAT from the OSPAR Convention and defines BAT through key elements such as the “latest stage of development” and “state-of-the-art processes” of “facilities and methods of operation” which are “practically suitable for limiting” environmental harm or pollution. Further, factors such as recent successful trials, technological advances, economic feasibility, time limits for installation, and the impact of the technology on the environment are considered as constitutive elements of BAT [See Appendix I, OSPAR Convention]. Additionally, the scope of the term “techniques” includes technologies. Albeit with a qualification that they must be accessible to operators and industrially scalable under economically and technically viable conditions.

On an overall assessment of BAT in international law, while States have a due diligence obligation to enact appropriate rules, regulations, and procedures to mitigate the effects of seabed mining on the environment, in effect, BAT also delegates action to contractors to innovate and develop technology that integrates these mitigating factors. Therefore, while States have a procedural obligation, the substantive obligation to implement the appropriate technology is incumbent upon contractors.

Mitigating the Risks of Seabed Mining vis-à-vis GHG Emissions

Having said that, opponents highlight that there are significant risks from seabed mining as well, particularly concerning the ocean’s function as a carbon sink. Insofar as carbon storage is concerned, the ocean’s upper layers absorb about a quarter of global anthropogenic CO₂ emissions, with only a tiny fraction, i.e., less than 1 percent, reaching the deep sea floor. There, microbes and marine fauna process some of this carbon, while the rest is buried beneath sediments up to 300 meters thick. This deep-sea burial is a vital element of the Earth’s carbon cycle, enabling the long-term storage of carbon and helping regulate the planet’s climate over millennia. 

However, according to the ISA, seabed mining disturbs upper sediments, and the thickness of sediment disturbance may vary based on the technology used (using the best available technique would constitute fulfilling the due diligence obligation). For instance, a comparison (see p. 23) of the 1979 test by Ocean Metals Company (OMCO), and 2022 test by Nauru Ocean Resources Inc (NORI) showcases that the difference in sediment disturbance has been reduced from 80 cm to 3 cm. In a similar vein, Impossible Metals (see p. 22-23) has developed prototype technology which has minimal disturbance of sediments owing to their suspended nodule collector technology. Further, these contain very little organic carbon compared to coastal area sediments (where most of the bottom trawling takes place and which releases as much as 370 million tonnes of the GHGs into the atmosphere each year) since most carbon is locked in inaccessible forms in deep-sea sediments. Consequently, given that only a small area of the ocean will be mined (0.4% of the ‘Area’), significant disruption to the global carbon cycle is unlikely, as most carbon remains securely buried in deep-sea sediments. 

Having said that, there still remain knowledge gaps in understanding the effects of midwater discharges on the midwater ecosystem and their ability to sequester carbon. And, to counter such risks, the current scientific consensus suggests that the dewatering discharges (mid-water plumes) must be delivered below the depths of 1500 to 2000 m (aphotic or disphotic zones). Further, much information is not available on GHG emissions from seabed mining itself, given that it has not yet commenced on a commercial scale. However, it is envisaged that primary sources of GHG emissions would largely emerge from the processing of seabed minerals on land rather than the mining itself.

In this regard, the ISA should be the appropriate forum where the scope and limits of GHG emissions by sponsoring states emerging from the activities in the Area (includes recovery of minerals, lifting them to the surface, and its shipboard processing, see para. 94-96, SDC AO) must be established through the Environmental Impact Assessments (EIAs) and is already part of the Environmental Impact Statement (EIS) of the contractors (Annex IV of draft exploitation regulations, 4.11 and 7.10). The ambitions to reduce emissions and their reporting must also form part of the Nationally Determined Contributions (NDCs) of the sponsoring states, given the contractual relationship that exists with the contractors, in fulfilment of their obligations under the Paris Agreement. 

Finally, as explained above the available regulatory instruments such as BAT would be critical in minimizing GHG emissions on the seafloor, water column and the ocean surface. Overall, an integrated view would require a continuous improvement in technology with a view to reduce emissions from activities in the Area to articulate the highest possible ambition and to fulfil the precautionary approach/ principle.

Conclusion

However, the question emerges – given the urgency of addressing the ‘self-inflicted’ harm of climate change upon the humanity, are there lessons we can draw from past experiences and devise sophisticated regulatory means of developing a system of exploration and exploitation of mineral resources from the deep sea in fulfilment of the substantive obligation of protection and preservation of the marine environment (thereby the climate system), and the procedural obligations concerning applying the precautionary approach/ principle including obligations such as the best available techniques and science.

In the view of the author, a genuine effort by states to meet their obligations as set out in the directly relevant applicable laws, together with good faith adherence to due diligence and direct obligations as outlined by the SDC AO and ICJ AO under an international oversight mechanism, may establish a regulatory environment conducive to developing a more sophisticated and mature relationship of humanity with the planet.

An excerpt in this blog has been taken from the author’s chapter on ‘Seabed mining technology and the precautionary approach’ in the upcoming book by James Kraska and Khanssa Lagdami, Marine Technology, Ocean Governance and the Law of the Sea (Cambridge University Press: 2025).

Photo attribution: Photo by Kseniya Lapteva on Unsplash