Introduction

Climate change constitutes the greatest global long-term threat to the health of the planet. States have however, been slow to recognize the implications of climate change for the oceans—in contrast to the atmosphere and biosphere. The subordinate status of the oceans in the climate regime complex is perpetuated by the 1992 United Nations Framework Convention on Climate Change (UNFCCC)¹ itself, which pays scant attention to both the impacts of climate change on the oceans and the capacity of the ocean to mitigate climate change through its function as a sink for carbon dioxide (CO₂). Scientific research now underpins an improved public and indeed policy understanding of the impacts climate change on the oceans: increased water temperature and its impact on ecosystems and species including coral reefs; sea level rise; and, ironically, a reduction in the capacity of the oceans to absorb CO₂.² An excess of CO₂ in the oceans also leads to a distinct but connected challenge: ocean acidification, the lowering of ocean pH,³ which poses a particular risk to calcifying organisms and reef ecosystems.⁴ However, the development of regulatory responses has thus far been fragmented, with a strong emphasis on soft targets and obligations designed to fill and bridge the gaps between instruments with a mandate to address climate change and ocean acidification. Moreover, as the largest natural sink for CO₂ the oceans also represent a potential or at least a partial solution for climate change. Mediating this tension between protection and exploitation, and the moral complexity underpinning actions designed to mitigate and adapt to climate change, will be one of the greatest challenges for the law of the sea in the twenty-first century. This essay will briefly explore the regime complex⁵ that applies to climate change and the oceans, and focuses on issues relating to mitigation, adaptation, and exploitation. It will highlight the disconnect between these regimes and the lack of a co-ordinated and integrated approach to oceans climate policy and conclude with selected recommendations to support the development of an overall legal and policy framework.

Mitigation

Although the 1982 United Nations Convention on the Law of the Sea (UNCLOS)⁶ purports to provide a constitution for the oceans, comprehensive in regulatory scope, it is not the primary regime for climate change mitigation. Its obligations on states to protect and preserve the marine environment⁷ and to prevent and mitigate all sources of marine pollution,⁸ whilst undoubtedly broad enough to encompass anthropogenic climate change and ocean acidification, are very general and arguably add little to existing external obligations relating to climate change. Articles 207 and 212 of UNCLOS, which set out obligations relating to land-based and atmospheric pollution respectively, neither establish global standards nor require states to comply with any such standards adopted. The one source of greenhouse gas emissions that is subject to specific regulation is ship-based greenhouse gas emissions, which since 1997, has been subject to regulation under Annex VI of the 1973/78 International Convention for the Prevention of Pollution from Ships.⁹ Under Article 211, paragraph 2, of UNCLOS these standards are applicable to all UNCLOS parties.

The overarching obligation underpinning the climate change regime is the stabilization of greenhouse gas concentrations in the atmosphere at a level that prevents dangerous interference with the climate system.¹⁰ The ‘climate system’ includes the oceans, but the focus of the UNFCCC is on the atmosphere, and this is demonstrated by the definition of climate change in the Convention itself as “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere…”¹¹ Targets to mitigate climate change are established under the 1997 Kyoto Protocol¹² (and 2012 Doha Amendment¹³) and, most recently, by the 2015 Paris Agreement,¹⁴ which establishes a global average temperature increase target of “well below 2°C above pre-industrial levels” with the aim of limiting the increase to 1.5°C.¹⁵ Notably, however, there has been minimal discussion as to the implications of a 2^oC rise for the oceans, and there is no comparable target relating to ocean pH change and there are no specific commitments in relation to the rise in the production of CO₂, which is the primary cause of ocean acidification.¹⁶

In an effort to bridge and indeed fill the gaps between the oceans and climate regimes a number of soft goals have been developed, particularly in relation to ocean acidification and the related problem of climate change. For example, Aichi Biodiversity Target 10 adopted under the auspices of the 1992 Convention on Biological Diversity calls upon parties to minimize the impacts of climate change or ocean acidification on coral reefs and other vulnerable ecosystems so as to maintain their integrity and ecosystem function by 2015.¹⁷ The UN General Assembly (UNGA) 2012 resolution adopting ‘The future we want’ called for collective action to prevent further ocean acidification and to take steps to promote ecosystem resilience.¹⁸ Most recently, Sustainable Development Goal 14.3, adopted by the UNga in 2015, urges states to “minimize and address the impacts of ocean acidification, including through enhanced scientific co-operation at all levels.”¹⁹ Soft targets and calls for action have been made by regional organizations such as the Arctic Council,²⁰ as well as by non-governmental and scientific organizations. Nevertheless, these initiatives fall short of binding and meaningful commitments relating to the mitigation of climate change and acidification as they relate to the oceans.

Adaptation

The second regulatory and policy intersection between climate change and the law of the sea lies in the area of adaptation. In contrast to mitigation, adaptation to climate change is an important theme within national, regional, and global instruments with oceans governance mandates. Adaptation, for example, is strongly endorsed within integrated approaches to oceans management, particularly in the context of integrated coastal zone management in regions such as the Mediterranean.²¹ The need to promote ecosystem resilience designed to withstand multiple pressures, including climate change, underpins the designation of modern marine protected areas (MPAs). For example, the Ross Sea MPA, established in 2016 by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR)²² in the Southern Ocean—and the largest MPA in international waters to date—is designed to conserve ecosystem function and establish reference areas for monitoring natural variability and long-term change “to better gauge the ecosystem effects of climate change and fishing.”²³ More generally, the impacts of climate change and ocean acidification on fish stocks is beginning to be considered as part of fisheries management by regional fisheries management organizations and states. CCAMLR, a leader in this area, is now required to consider climate change and ocean acidification when adopting conservation measures (including catch limits)²⁴ and, in 2016 anticipating the need to take precautionary action to protect areas newly exposed by ice retreat, the Commission adopted a measure permitting those areas to be designated scientific special areas.²⁵ Perhaps the most fundamental area of adaptation arises in the context of determining baselines and maritime boundaries which change or disappear altogether with sea level rise. The question of whether the traditional rules of maritime delimitation continue to apply, or whether new solutions such as fixed baselines and outer limits by global agreement or otherwise will be developed, has yet to be determined.²⁶

Exploitation

As the largest natural sink for CO₂ and as a source of renewable energy, the ocean provides clear potential for exploitation in order to mitigate or otherwise address the impacts of climate change. At the forefront of regulating such exploitation is the dumping regime, in particular, the 1996 Protocol to the 1972 London Convention.²⁷ In particular, in 2006, the Protocol was amended in order to expressly permit and create a legal basis for the disposal of CO₂ into sub-seabed geological formations.²⁸ More controversially, in 2013, the Protocol was amended to create an explicit mandate for the regulation of ocean fertilization, a technique designed to draw down CO₂ from the atmosphere into the oceans, and, in the future, potentially other forms of marine geoengineering.²⁹

Currently only ocean fertilization for scientific purposes is permitted under the Protocol provided that it is carried out consistently with the conditions of the Protocol, including the risk assessment framework.³⁰ The relationship between the Protocol and UNCLOS with respect to ocean fertilization is complex and, furthermore, whether the Protocol has a mandate to address marine geoengineering more generally is debatable.³¹ Currently, the emerging regime for ocean fertilization—and possibly marine geoengineering more generally—is disconnected from the climate change regime. Linking the regimes in order to develop a consistent and coherent approach to ocean climate governance constitutes a significant challenge to twenty-first century law of the sea.

Concluding Remarks

Currently the law of the sea lacks an overall framework to manage the oceans–climate regime complex. The absence of binding targets relating to ocean pH and CO₂ emissions and the development of rules relating to marine geoengineering outside of broader climate policy considerations demonstrates the limits of the law of the sea to address this important issue. The development of a coherent and integrated policy framework is essential going forward and could be adopted as an accord under the 1992 UNFCCC or as a UNGA resolution. Such a framework could provide the basis for ocean-climate related targets, including the development of nationally determined contributions³² of specific application to the oceans. The framework could also establish principles relating to the development of policy and rules around exploiting the oceans for climate change mitigation, including geoengineering. And finally, such a framework could provide a basis for linking regimes and institutions, navigating the regime complex governing the oceans–climate nexus.