The Legal Framework for Carbon Capture and Storage (CCS) in Shipping

Maritime transport remains a primary facilitator of global trade and economic continuity. The industry emits about 3% of global greenhouse gases, a figure that is projected to increase if left unregulated. Carbon Capture and Storage (CCS) has been identified as a technological intervention capable of reducing emissions in hard-to-abate sectors such as shipping. The legal and regulatory dimensions governing the integration of CCS into maritime operations determine both the feasibility and legitimacy of its application. International, regional, and national frameworks must align to prevent jurisdictional gaps and regulatory fragmentation. The analysis that follows evaluates how legal instruments interact with technological capabilities, focusing on the International Maritime Organization (IMO), United Nations Convention on the Law of the Sea (UNCLOS), and domestic legal structures.

International Legal Context

IMO’s Regulatory Mandate

The International Maritime Organization has established foundational principles for maritime emissions reduction under MARPOL Annex VI. CCS deployment intersects with these principles through regulation of onboard storage, transport of captured carbon dioxide, and transboundary disposal. The IMO’s Marine Environment Protection Committee (MEPC) has addressed carbon management through the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII). However, current instruments lack explicit provisions for CCS integration, creating interpretive ambiguity. Consequently, ship operators must navigate overlapping obligations without unified compliance criteria.

UNCLOS and the Rights of Coastal and Flag States

The United Nations Convention on the Law of the Sea defines jurisdictional boundaries over the continental shelf, exclusive economic zone, and territorial sea. These boundaries determine which state holds responsibility for storage sites and carbon transport infrastructure. Coastal states have sovereign rights to explore and exploit natural resources, which extend to sub-seabed geological formations suitable for carbon storage. Article 194(2) of UNCLOS obliges states to ensure that activities under their jurisdiction do not cause transboundary harm. Therefore, CCS activities conducted by ships or offshore installations require coordination between flag states and coastal states to ensure compliance with environmental standards.

The London Protocol and Cross-Border Storage

The 1996 Protocol to the London Convention regulates marine pollution through waste dumping. In 2006, amendments allowed carbon dioxide streams from CCS projects to be considered for sub-seabed geological storage. However, the 2009 amendment enabling transboundary movement of CO₂ streams for storage has not been widely ratified, creating legal uncertainty for shipping operators engaged in cross-jurisdictional carbon transport. Without full ratification, legal authority for transboundary injection remains fragmented, discouraging commercial investment in maritime CCS infrastructure.

Regional Frameworks and Emerging Jurisdictional Overlaps

European Union Regulation

The European Union’s CCS Directive (2009/31/EC) sets standards for geological storage of carbon dioxide within EU territory. The directive mandates monitoring, liability allocation, and closure procedures for storage sites. Although designed primarily for stationary facilities, the directive’s scope may extend to maritime storage if vessels are used as temporary transporters of captured CO₂. Furthermore, the EU Emissions Trading System (EU ETS) places shipping under its scope from 2024, incentivizing decarbonization technologies. The legal recognition of CCS within the ETS framework ensures that captured and permanently stored CO₂ is exempt from emission allowances, thereby aligning financial incentives with regulatory compliance.

United States Legal Position

The United States regulates carbon storage through the Safe Drinking Water Act and the Class VI well program administered by the Environmental Protection Agency (EPA). While these rules cover land-based storage, maritime applications remain governed by the Clean Water Act and the Outer Continental Shelf Lands Act. CCS operations conducted from U.S.-flagged vessels or on the U.S. continental shelf would require federal permits addressing injection safety and environmental protection. Legal clarity remains limited on whether captured CO₂ transported via ships to foreign storage sites constitutes “export” under environmental statutes, raising compliance challenges under both domestic and international trade law.

Asian Legal Developments

Japan, South Korea, and Singapore are advancing regional CCS governance models emphasizing technological standardization and cross-border cooperation. Japan’s CCS Act of 2022 provides legal definitions for storage rights and liability allocation. Singapore’s Maritime and Port Authority has initiated regulatory frameworks for onboard capture pilot programs under existing port regulations. These developments illustrate regional differentiation, where legal systems adapt to maritime emission control through both environmental and energy laws.

Legal Challenges in Implementation

Ownership and Liability of Captured Carbon

Legal uncertainty persists over ownership of carbon once captured onboard a vessel. Determining the entity responsible for permanent storage, leakage risk, and long-term monitoring remains unresolved. The concept of “carbon custody” must evolve to delineate liability boundaries between the shipowner, the charterer, and the storage operator. Existing maritime law, primarily structured around cargo ownership and carriage of goods, lacks provisions for intangible environmental commodities like captured carbon dioxide. Without explicit contractual frameworks, potential leakage or unauthorized release may trigger complex litigation under both environmental and maritime liability conventions.

Regulatory Fragmentation

The absence of unified standards across jurisdictions increases compliance costs and operational risk. Maritime CCS activities intersect multiple regimes: environmental protection, energy regulation, marine safety, and trade law. Each regime imposes distinct permitting and reporting obligations. Consequently, operators face overlapping jurisdictional mandates that inhibit rapid deployment. A harmonized international framework could streamline authorization procedures, but consensus remains politically constrained.

Monitoring, Verification, and Reporting

CCS projects require stringent monitoring to confirm permanent sequestration. Verification processes under international maritime law remain underdeveloped. Existing mechanisms, such as the Ship Energy Efficiency Management Plan (SEEMP), track energy use but not carbon storage integrity. Integration of digital reporting systems linked to port state control could strengthen transparency. However, absent shared technical protocols, verification data lacks comparability across fleets.

Interaction between CCS and Maritime Liability Regimes

Civil Liability and Environmental Damage

The International Convention on Civil Liability for Oil Pollution Damage (CLC) provides a precedent for strict liability and mandatory insurance. A similar model could regulate carbon storage-related damage. Operators could be held strictly liable for environmental harm resulting from CO₂ leakage, with mandatory insurance or compensation funds established under IMO oversight. The principle of “polluter pays” applies, but determining the polluter’s identity within the CCS chain complicates enforcement.

Salvage and Hazardous Material Regulations

Captured CO₂ is a compressed gas classified as a hazardous substance under the International Maritime Dangerous Goods (IMDG) Code. If a ship carrying stored carbon encounters distress, salvage operations fall under the 1989 Salvage Convention. The presence of hazardous carbon cargo imposes additional obligations for safety and containment. Legal clarity on whether venting during emergencies constitutes pollution under MARPOL remains limited, exposing operators to potential liability under multiple regimes.

Integration with Climate Policy Instruments

Linking CCS to Carbon Pricing

Legal frameworks must align CCS implementation with carbon pricing instruments. Under cap-and-trade systems, credits should be issued only when storage is verified as permanent. The legal definition of “permanence” must encompass not only geological stability but also compliance with monitoring obligations. Carbon markets depend on credible verification systems; thus, harmonization between environmental law and financial regulation becomes essential. The European Union’s recognition of CCS within the ETS provides a replicable model.

Compatibility with IMO Greenhouse Gas Strategy

The IMO’s revised greenhouse gas strategy targets net-zero emissions by 2050. CCS aligns with this objective but requires legal integration through amendments to MARPOL or new conventions. A formal annex dedicated to carbon storage could codify standards for capture equipment, transport safety, and verification procedures. Absent such codification, CCS will remain a supplementary measure with uncertain compliance implications.

Ethical and Governance Dimensions

Environmental Justice and Equity

Legal regimes governing CCS in shipping must consider the distributional consequences of technological deployment. Developing states reliant on maritime transport could face disproportionate compliance burdens without corresponding financial support. International law mandates capacity-building assistance under Principle 7 of the Rio Declaration. Therefore, equitable access to CCS technology and finance forms an essential legal requirement. Failure to incorporate distributive fairness could undermine global participation in maritime decarbonization.

Transparency and Accountability

Governance legitimacy depends on transparency. Legal instruments should require public disclosure of storage site data, risk assessments, and monitoring results. Freedom of information provisions can reduce mistrust among stakeholders. Accountability mechanisms, including independent audits and state reporting under international environmental agreements, would strengthen regulatory credibility.

Pathways for Legal Harmonization

Developing a Global Maritime CCS Convention

Creating a specialized convention under IMO auspices could consolidate fragmented legal obligations. Such an instrument would define legal responsibilities for capture, transport, and storage within maritime contexts. It would also establish uniform standards for liability, verification, and dispute resolution. The success of similar frameworks, such as the Ballast Water Management Convention, demonstrates that sector-specific treaties can achieve technical harmonization without duplicating broader environmental law.

Amending Existing Instruments

Alternatively, existing conventions could be amended to include CCS-specific provisions. MARPOL Annex VI could introduce new chapters defining operational criteria for onboard capture systems. The London Protocol could expedite ratification of transboundary CO₂ storage amendments. UNCLOS could incorporate interpretative guidelines clarifying jurisdictional authority over sub-seabed storage. These incremental legal adjustments may provide faster implementation than drafting new instruments.

National Legal Reforms

States must adapt domestic laws to facilitate CCS deployment. Legislation should define storage rights, monitoring duties, and liability allocation. Regulatory authorities must issue clear permits for carbon transport and storage operations conducted from national ports or continental shelves. Coordination among ministries responsible for energy, environment, and maritime affairs is necessary to prevent bureaucratic conflict.

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Economic and Institutional Considerations

Financial Instruments Supporting Compliance

The legal framework must integrate economic incentives for compliance. Carbon credit schemes, green bonds, and public–private partnerships can finance CCS infrastructure. Legal instruments should specify eligibility conditions for financial incentives based on verified emission reductions. Regulatory agencies must establish transparent accounting methods to prevent double counting of stored carbon.

Institutional Coordination

Institutional fragmentation weakens enforcement. Effective governance requires coordination between international maritime authorities, environmental agencies, and trade regulators. Institutional linkages can ensure consistent interpretation of legal norms across regimes. Standard-setting bodies such as the International Organization for Standardization (ISO) can complement regulatory efforts through technical guidelines aligned with legal obligations.

Future Directions

Technological Standardization and Legal Predictability

Legal certainty encourages investment. Standardizing CCS technology through binding specifications reduces risk. Legal predictability regarding data ownership, monitoring obligations, and liability allocation will determine investor confidence. Technology-neutral legislation can accommodate evolving capture methods without requiring frequent amendment.

Global Enforcement Mechanisms

Compliance enforcement must evolve beyond national borders. The IMO could establish a global compliance committee similar to the one under the Kyoto Protocol. Such a body could review national reports, assess compliance, and impose corrective actions. Enforcement mechanisms relying solely on flag-state control are insufficient, given the transboundary nature of maritime emissions.

Conclusion

Legal regulation of Carbon Capture and Storage in shipping remains in its formative stage. International law provides partial coverage through instruments like MARPOL, UNCLOS, and the London Protocol, but gaps persist in liability, monitoring, and cross-border coordination. Regional frameworks such as the EU Directive and national statutes in Japan and the United States illustrate progressive adaptation but remain fragmented. Achieving effective governance requires harmonized legal instruments, transparent verification systems, and equitable access mechanisms. The integration of CCS into the maritime legal order will depend on institutional coordination, financial alignment, and enforceable standards capable of reconciling environmental protection with economic continuity. The legal trajectory of CCS in shipping will shape not only industry compliance but also the broader architecture of international environmental law.

References

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• Houghton, D. & Ryding, S. (2023). Maritime Carbon Capture Regulation: Challenges and Legal Gaps. Marine Policy, 150, 105672. [https://doi.org/10.1016/j.marpol.2023.105672]

• Johansson, L. (2020). UNCLOS and Carbon Sequestration: Legal Dimensions of Sub-Seabed Storage. International Environmental Agreements, 20(3), 421–438. [https://doi.org/10.1007/s10784-020-09492-9]

• Tanaka, Y. (2024). The Legal Interface between IMO Regulations and Carbon Capture Technologies. Journal of Maritime Law and Commerce, 55(2), 187–214. [https://doi.org/10.54648/marc.2024.0187]

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