London Convention 1972 + London Protocol 1996: Marine Dumping

Background: 1972 Stockholm UN Conference + 1972 London signing

The London Convention 1972 emerged from a confluence of late-1960s and early-1970s public-policy alarm at the scale of ocean dumping. Three drivers converged. First, marine scientific evidence of widespread persistent organic pollutant accumulation in pelagic and benthic biota, including the high-profile DDT and PCB signatures detected in open-ocean fish, sea birds and marine mammals through the 1960s. Second, public revulsion at the deliberate disposal at sea of obsolete chemical-weapon stockpiles, illustrated by the United States Army Operation CHASE (Cut Holes And Sink ‘Em) programme of 1967 to 1970 in which surplus chemical and conventional munitions were loaded onto retired vessels and scuttled in deep water off the Atlantic seaboard, and by the Operation Hat nerve-agent dumping programme of the 1960s in the Pacific. Third, the United Nations Conference on the Human Environment, held in Stockholm from 5 to 16 June 1972, which adopted the Stockholm Declaration and the Action Plan for the Human Environment, with Recommendation 86 expressly calling on governments to take steps to bring under early international control the dumping of wastes at sea.

The Stockholm Conference catalysed two parallel diplomatic tracks. A regional track produced the Convention for the Prevention of Marine Pollution by Dumping from Ships and Aircraft signed in Oslo on 15 February 1972, the Oslo Convention, covering the North-East Atlantic between contracting states from Iceland to Portugal. A global track produced the inter-governmental conference convened in London from 30 October to 13 November 1972 under the auspices of IMCO, which negotiated and adopted the global Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter on 13 November 1972. The conference was attended by approximately eighty states and adopted the Convention text by consensus, with signature opened on 29 December 1972.

The 1972 negotiations adopted a blacklist regulatory architecture under which dumping is in principle permitted subject to permit, with the most hazardous categories of waste prohibited absolutely (Annex I) and a second tier requiring a special permit (Annex II), with general considerations for permit issuance set out in Annex III. The blacklist architecture reflected the prevailing 1960s and 1970s industrial-policy assumption that dumping was a legitimate waste-management option for materials that could not be readily incinerated or land-filled, subject to environmental controls keyed to the most acutely hazardous substances.

1975 entry into force + 88 contracting parties

The London Convention 1972 entered into force on 30 August 1975, thirty days after the deposit of the fifteenth instrument of ratification, acceptance, approval or accession with the IMCO secretariat in London under Article XIX of the Convention. The fifteenth deposit was completed in late July 1975 by the United Kingdom, joining earlier ratifications by the United States, Canada, the Soviet Union, France, Norway, Sweden, Denmark, the Federal Republic of Germany, Spain, the Netherlands, Iceland, Finland, Tonga and South Africa.

The Convention entered into force ahead of the MARPOL Convention (1973/1978, in force 1983) and the United Nations Convention on the Law of the Sea (UNCLOS) (1982, in force 1994), making the London Convention the first global treaty on marine pollution of any kind. Its first-mover status shaped the architecture of subsequent global marine-pollution instruments and the institutional architecture of the IMO Marine Environment Division.

The contracting-party number grew steadily through the 1970s, 1980s and 1990s. By 1985 the Convention had approximately fifty parties; by 1995 it had approximately seventy-five; and by 2010 it stabilised in the mid-eighties. As of 2026 the 88 contracting parties include almost all major flag states, all G7 economies, all BRICS economies, all major coastal-state regional powers, and a representative spread of small island developing states from the Caribbean, Pacific and Indian Ocean basins. Notable non-parties include several land-locked states for which the Convention has limited operational relevance, and a small number of coastal states for which accession is under domestic consideration.

The Convention is governed by an annual Consultative Meeting of Contracting Parties (LC) held at IMO headquarters in London, which adopts amendments to the Convention text and to the Annexes by qualified majority procedures and adopts non-binding resolutions on interpretation and implementation by consensus. Amendments to the Convention text require ratification by two-thirds of contracting parties to enter into force, while amendments to the Annexes enter into force for all parties one hundred days after adoption unless a party opts out within that window.

1996 Protocol adoption + 2006 entry into force + 53 parties

By the early 1990s the operational and conceptual limits of the 1972 blacklist architecture had become apparent. Three drivers motivated a thorough overhaul. First, the precautionary-approach paradigm, which had emerged through the 1980s North Sea Ministerial Conferences and entered the global lexicon through the 1992 Rio Declaration Principle 15, did not fit comfortably with the 1972 permissive-by-default architecture. Second, the 1972 Convention had been amended piecemeal through twenty-plus years of resolutions and annex amendments, producing an inconsistent and difficult-to-navigate operational text. Third, the 1996 OSPAR Convention had been signed in 1992 with a reverse-list architecture in its Annex II, and the 1992 Helsinki Convention Annex III had taken a similar approach for the Baltic; the global instrument was lagging the regional ones.

The 1996 Protocol was negotiated through 1995 and 1996 in a series of intersessional meetings under the LC framework and was adopted at a Conference of Contracting Parties on 7 November 1996. It is structured as a Protocol rather than as an amended Convention because the architectural overhaul was too radical to be compatible with the 1972 permissive-by-default text. Once in force between parties to both instruments, the Protocol effectively replaces the 1972 Convention; the 1972 Convention continues to apply only as between states that are party to it but not to the Protocol.

The Protocol entered into force on 24 March 2006, thirty days after the deposit of the twenty-sixth instrument of ratification under Protocol Article 25, with the threshold reached through ratifications including the United Kingdom, Australia, Canada, Germany, France, Spain, Norway, Denmark, Sweden, Iceland, the Republic of Korea, Egypt, Mexico, Saint Lucia, Trinidad and Tobago, Vanuatu, Sierra Leone, Saudi Arabia, the Philippines, Belgium, Switzerland, Slovenia, Ireland, the Netherlands, Bulgaria and Italy.

As of 2026 the 53 contracting parties to the 1996 Protocol include all major Western European maritime states, the United Kingdom, Norway, Australia, New Zealand, Canada, Japan, the Republic of Korea, the Philippines, South Africa, Egypt, Saudi Arabia, Iran, the United Arab Emirates and a representative subset of the Caribbean, Pacific and Indian Ocean small island states. Notable non-parties include the United States (signed 31 March 1998 but not yet ratified as of 2026 due to United States Senate consent requirements under domestic law), the Russian Federation, India, China, Brazil, Argentina, Indonesia, Malaysia, Thailand and Singapore. The non-ratification by these major maritime economies is the principal political and operational limit on the global reach of the Protocol regime, although several non-parties (notably the United States) implement Protocol-equivalent rules under domestic ocean-dumping legislation.

1972 vs 1996 architecture: blacklist vs reverse list

The two instruments use fundamentally different regulatory defaults. The table below summarises the key structural differences.

The blacklist default meant that any waste not on the Annex I prohibited list and not on the Annex II special-permit list could be dumped under a general permit keyed to Annex III environmental considerations. The reverse-list default eliminates that gap entirely: anything not on the Annex 1 list is prohibited, and the burden of justification falls on the proponent.

1972 Convention “blacklist” approach (Annex I/II/III)

The 1972 Convention adopts a three-tier blacklist architecture. Annex I sets out the absolutely prohibited categories of waste, dumping of which is forbidden under Article IV(1)(a). The 1972 Annex I list includes: organohalogen compounds, mercury and mercury compounds, cadmium and cadmium compounds, persistent plastics and other persistent synthetic materials capable of seriously interfering with fishing, navigation or other legitimate uses of the sea, crude oil and its wastes, refined petroleum products, petroleum distillate residues and any mixtures containing such substances, high-level radioactive wastes as defined by the International Atomic Energy Agency, and materials produced for biological and chemical warfare. Annex I is supplemented through resolutions including the 1993 LC.51(16) full radioactive ban discussed below and various incineration-related resolutions through the 1980s.

Annex II sets out wastes requiring a special permit before dumping under Article IV(1)(b). The Annex II list includes: wastes containing significant amounts of arsenic, lead, copper, zinc, organosilicon compounds, cyanides, fluorides, pesticides and their by-products not covered by Annex I, acids and alkalis of high toxicity, beryllium, chromium, nickel and vanadium and their compounds, containers, scrap metal and other bulky wastes liable to sink to the sea bottom and present a serious obstacle to fishing or navigation, and substances which, although non-toxic, may become harmful by reason of the quantities dumped or are liable to seriously reduce amenities.

Annex III sets out the general considerations for issuing dumping permits under Articles IV(2) and IV(3). Annex III addresses three groups of considerations: (a) characteristics and composition of the matter (total amount, average composition, persistence, accumulation in biota, susceptibility to physical, chemical and biochemical changes, probability of producing taints affecting marketability of fisheries resources); (b) characteristics of the dumping site and method of deposit (location, depth, distance from coast and amenities, dispersal characteristics, current characteristics, hydrographic, meteorological and biological conditions, existence and effects of other dumping); and (c) general considerations and conditions (effects on amenities, marine life, fisheries, other uses of the sea, alternatives to dumping at sea).

The 1972 architecture is permissive by default in the gap between the prohibited Annex I categories and the special-permit Annex II categories: a waste neither prohibited (Annex I) nor on the special-permit list (Annex II) can be dumped under a general permit issued by the competent national authority on the Annex III considerations. This permissive default became the principal operational and conceptual limit of the 1972 framework and was replaced by the 1996 Protocol reverse-list architecture.

1996 Protocol “reverse list” approach

The 1996 Protocol inverts the 1972 default. Protocol Article 4 establishes the general obligation: contracting parties shall prohibit the dumping of any wastes or other matter with the exception of those listed in Annex 1. The reverse-list architecture means that any waste or other matter not on the Annex 1 list is prohibited from dumping; only the seven listed categories may be considered for dumping subject to permit and only if the assessment in Annex 2 demonstrates that dumping is the most environmentally appropriate option.

The reverse-list paradigm aligns the global instrument with the precautionary approach codified in Protocol Article 3(1) and with the polluter-pays principle codified in Protocol Article 3(2). It eliminates the 1972 permissive-by-default gap, places the burden of justification on the proponent of any dumping operation, and integrates the sub-seabed CCS, marine geoengineering and ocean-CDR governance work that has dominated the LC/LP agenda since the mid-2000s. The Protocol Annex 2 sets out the assessment of wastes or other matter that may be considered for dumping in detail, including waste prevention audit, consideration of waste management options, chemical, physical and biological properties, action lists, dump-site selection, assessment of potential effects, monitoring and permit conditions.

The reverse-list approach also closes the 1972 framework’s incineration-at-sea loophole. Protocol Article 5 prohibits incineration at sea outright, with the exception only of incineration on board a vessel for the purpose of disposal of wastes generated during the normal operation of the vessel. The 1972 Convention had previously regulated incineration at sea under Annex I and various 1980s resolutions but had not banned it outright; the 1996 Protocol prohibition was a clean break.

Protocol Annex 1: 7 categories considered for dumping

The Protocol Annex 1 list of wastes that may be considered for dumping comprises seven categories:

(1) Dredged material, the largest single category by global volume (see below); (2) sewage sludge, with the European Union and several other regions effectively prohibiting sewage-sludge dumping under domestic and regional law since 1998; (3) fish waste, or material resulting from industrial fish processing operations, principally relevant to fish-processing industries in Iceland, Norway, the Faroes, Alaska, the Maritime Provinces of Canada and parts of Asia; (4) vessels and platforms or other man-made structures at sea, with the deep-water disposal of decommissioned offshore platforms governed by additional OSPAR Decision 98/3 in the North-East Atlantic and equivalent regional rules elsewhere; (5) inert, inorganic geological material, principally rock excavated from coastal and undersea engineering projects; (6) organic material of natural origin, principally agricultural and forestry residues with limited practical relevance; and (7) bulky items primarily comprising iron, steel, concrete and similarly unharmful materials for which the concern is physical impact, with disposal limited to circumstances where wastes are generated at locations such as small islands with isolated communities having no practicable access to disposal options other than dumping.

The 2007 amendment to Annex 1 added an eighth conceptual category for carbon dioxide streams from CO2 capture processes for sequestration under Resolution LP.1(1), discussed below.

Precautionary approach + polluter-pays codification

Protocol Article 3(1) codifies the precautionary approach: “in implementing this Protocol, Contracting Parties shall apply a precautionary approach to environmental protection from dumping of wastes or other matter whereby appropriate preventative measures are taken when there is reason to believe that wastes or other matter introduced into the marine environment are likely to cause harm even when there is no conclusive evidence to prove a causal relation between inputs and their effects.” This is one of the earliest treaty-text codifications of the precautionary approach in the global maritime regulatory architecture, predating equivalent codifications in many later instruments.

Protocol Article 3(2) codifies the polluter-pays principle: “taking into account the approach that the polluter should, in principle, bear the cost of pollution, each Contracting Party shall endeavour to promote practices whereby those it has authorized to engage in dumping or incineration at sea bear the cost of meeting the pollution prevention and control requirements for the authorized activities, having regard to the public interest.” The polluter-pays codification is more cautious than the precautionary-approach codification, reflecting the 1996 negotiating compromise on cost-allocation principles, but it nonetheless places the polluter-pays principle at the core of the modern London regime.

Protocol Article 3(3) and Article 3(4) add complementary commitments: parties shall act so as not to transfer damage or likelihood of damage from one part of the environment to another or transform one type of pollution into another (Article 3(3)), and no provision of the Protocol shall be interpreted as preventing parties from taking, individually or jointly, more stringent measures (Article 3(4)). These two articles complete the modern environmental-policy architecture of the Protocol and establish its compatibility with the more stringent regional regimes under OSPAR, Helsinki, Barcelona and others.

“No other practicable solution” rule

The Protocol Annex 2 assessment framework requires that dumping be permitted only after a waste-management options review demonstrates that there is no other practicable solution. The waste prevention audit requires the proponent to have considered, in sequence: (i) waste reduction at source; (ii) re-use; (iii) off-site recycling; (iv) destruction of hazardous constituents; (v) treatment to reduce or remove hazardous constituents; and (vi) disposal on land, into air, or in water. Disposal at sea is the option of last resort, and the permit may issue only when the alternatives have been demonstrated to be impracticable, more environmentally damaging or otherwise inappropriate.

The “no other practicable solution” rule is operationalised through the waste prevention audit required in Annex 2 paragraph 3, the action lists required in Annex 2 paragraph 9, and the comparative assessment required in Annex 2 paragraph 10. The action lists screen specific contaminants and contaminant levels against upper and lower thresholds: wastes above the upper level are categorically not eligible for dumping consideration; wastes below the lower level are eligible subject to assessment; wastes in the intermediate range require detailed comparative assessment. National competent authorities maintain action lists keyed to local environmental conditions and waste-stream characteristics.

Secretariat: IMO London + OLCP office

The London Convention and Protocol secretariat is hosted by the International Maritime Organization at IMO Headquarters, 4 Albert Embankment, London SE1 7SR, United Kingdom, and is staffed through the Office for the London Convention and Protocol (OLCP) within the IMO Marine Environment Division. OLCP is led by a Head of Office reporting to the Director of the Marine Environment Division and provides administrative, scientific and legal support to the Consultative Meeting of Contracting Parties to the 1972 Convention and the Meeting of Contracting Parties to the 1996 Protocol, which since the early 2000s have been held jointly each year, typically in the autumn at IMO Headquarters.

OLCP also services the Scientific Group under the 1972 Convention and the Scientific Group under the 1996 Protocol, which meet jointly each year in spring (the LC/LP Joint Scientific Group), typically hosted by a contracting party rather than at IMO. Recent host states include Norway, Australia, Canada, the Republic of Korea, the United Kingdom, the Netherlands, Italy and Mexico. The Joint Scientific Group reviews scientific aspects of waste assessment, dumping site selection, post-disposal monitoring, ocean-CDR proposals, marine-geoengineering proposals, sub-seabed CCS proposals and emerging technical issues, and reports to the Consultative Meeting and Meeting of Parties each autumn.

OLCP additionally services the Compliance Group under the 1996 Protocol, established under Protocol Article 11, which assesses compliance by parties with their reporting and substantive obligations under the Protocol. The Compliance Group meets annually in conjunction with the Consultative Meeting and Meeting of Parties and operates on a facilitative, non-adversarial basis.

Predecessor regional treaties: Oslo 1972, Helsinki 1974

Two regional dumping treaties predate or coincide with the 1972 London Convention and shaped its architecture. The Convention for the Prevention of Marine Pollution by Dumping from Ships and Aircraft, signed in Oslo on 15 February 1972, the Oslo Convention, covered the North-East Atlantic between contracting states from Iceland to Portugal. The Oslo Convention adopted a similar three-tier blacklist architecture and was the operational template for the November 1972 London negotiations. The Oslo Convention was subsequently absorbed into the 1992 OSPAR Convention Annex II (“Prevention and Elimination of Pollution by Dumping or Incineration”), which entered into force on 25 March 1998 and is documented in the OSPAR Convention 1992 article.

The Convention on the Protection of the Marine Environment of the Baltic Sea Area, signed in Helsinki on 22 March 1974 and entering into force on 3 May 1980, the Helsinki Convention 1974/1980, covered the Baltic Sea between the seven Baltic coastal states and the European Communities. The 1974 Helsinki Convention prohibited dumping outright in the Baltic with very narrow exceptions and was the most stringent regional dumping regime of the 1970s. It was superseded by the 1992 Helsinki Convention in force 17 January 2000, documented in the Helsinki Convention 1992 article, which retains the dumping prohibition in Annex III with limited exceptions for dredged material.

The London 1972 negotiators were familiar with both regional regimes and adopted the three-tier blacklist architecture of the Oslo Convention as the global template, while leaving regional regimes free to adopt more stringent rules under the Article VIII “more stringent measures” savings clause. This subsidiarity architecture has been maintained through the 1996 Protocol Article 3(4) “more stringent measures” clause.

Resolution LC.51(16) 1993 radioactive waste full ban

The 1972 Convention Annex I prohibition on dumping of high-level radioactive waste as defined by the IAEA left low-level and intermediate-level radioactive waste eligible for dumping under special permit subject to Annex II and Annex III. Through the 1970s and 1980s, several states (notably the United Kingdom, the United States, the Soviet Union, the Netherlands, Belgium, Switzerland, France and Japan) dumped low-level and intermediate-level radioactive waste in the deep North-East Atlantic, the Pacific and parts of the Arctic. The cumulative volume dumped through 1982 has been estimated at approximately 142,000 tonnes of waste with a total activity of approximately 1.14 PBq.

Following the 1985 voluntary moratorium on low-level radioactive waste dumping (adopted by Resolution LDC.21(9)) and through years of debate, the Sixteenth Consultative Meeting in November 1993 adopted Resolution LC.51(16), which converted the moratorium into a full ban on dumping of all radioactive wastes and other radioactive matter into the sea. The amendment to Annex I was adopted by the requisite majority and entered into force in 1994 for all parties that had not opted out within the standard one-hundred-day window. The Russian Federation initially opted out but subsequently accepted the amendment in 2005 following remediation of legacy Soviet-era Arctic disposal sites.

The 1993 full ban on radioactive waste sea disposal is one of the most consequential resolutions in the LC’s history and aligns the regime with the analogous prohibitions on nuclear weapons in space under Outer Space Treaty 1967 Article IV (see below). The full ban is incorporated into the 1996 Protocol Annex 1 by the absence of radioactive waste from the seven permitted categories.

Resolution LC-LP.1 2008 ocean fertilization ban

Through the early 2000s, several commercial proposals emerged for iron ocean fertilization programmes, principally on the basis that pulse iron addition to high-nutrient low-chlorophyll waters of the Southern Ocean and parts of the Pacific would stimulate phytoplankton blooms that would draw down atmospheric CO2 and sequester carbon to the deep sea on biological-pump time-scales. The proposals raised acute scientific concerns about ecological side-effects (harmful-algal-bloom risk, deep-water hypoxia, food-web disruption, methane and nitrous oxide release) and acute legal concerns about whether iron fertilization constituted “dumping” under the London Convention.

The Thirtieth Consultative Meeting and Third Meeting of Contracting Parties in October 2008 adopted Resolution LC-LP.1(2008) on the Regulation of Ocean Fertilization. The Resolution affirmed that the LC and LP scope includes ocean fertilization activities, that ocean fertilization activities other than legitimate scientific research should not be allowed, that to provide for legitimate scientific research such activities should be assessed under an assessment framework to be developed, and that scientific research proposals should be assessed on a case-by-case basis using the assessment framework. The Resolution effectively prohibited commercial ocean fertilization and constrained scientific ocean fertilization to a permit-based regime.

The 2010 Eighth Meeting of Parties subsequently adopted the Assessment Framework for Scientific Research Involving Ocean Fertilization through Resolution LC-LP.2(2010), and the 2013 Eighth Meeting of Parties adopted the Resolution LP.4(8) marine geoengineering amendment discussed below, which would extend the architecture to all marine geoengineering activities once in force.

Resolution LP.1(1) 2007: CO2 sub-seabed sequestration

The Protocol Annex 1 list as originally adopted in 1996 did not contemplate carbon dioxide capture and storage (CCS) in sub-seabed geological formations as a permitted dumping category. By the mid-2000s, scientific and policy interest in CCS as a climate-mitigation technology had grown rapidly, with the Sleipner project in the Norwegian sector of the North Sea injecting approximately 1 million tonnes of CO2 per year into the Utsira saline aquifer since 1996, the Snøhvit project entering operation in 2008, and a pipeline of additional North Sea, Mediterranean, Australian and East Asian projects in development.

The Twenty-Ninth Consultative Meeting and Second Meeting of Contracting Parties, held 30 October to 3 November 2006, adopted Resolution LP.1(1) amending Protocol Annex 1 to add an eighth category for carbon dioxide streams from CO2 capture processes for sequestration in sub-seabed geological formations. The amendment entered into force on 10 February 2007 under the Article 22 amendment-to-annexes procedure: one hundred days after adoption on 3 November 2006, with no contracting party opting out within the window.

The amendment authorised dumping of CO2 streams subject to three conditions: (i) disposal must be into a sub-seabed geological formation; (ii) the streams must consist overwhelmingly of CO2 (with incidental associated substances derived from the source material and the capture and sequestration processes); and (iii) no wastes or other matter may be added for the purpose of disposal. The accompanying 2007 Specific Guidelines for Assessment of CO2 Streams govern the permit assessment, including site characterisation, risk assessment, monitoring, mitigation and reporting.

The 2007 amendment was the first global treaty framework for sub-seabed CCS and remains the principal global instrument governing sub-seabed CO2 sequestration, with national CCS regulatory frameworks in the United Kingdom (Offshore Storage Regulations 2010), Norway (CO2 Storage Regulations 2014), Australia (OPGGSA 2006 amendments), Japan, the Republic of Korea, the European Union (CCS Directive 2009/31/EC) and others all keyed to the LP.1(1) framework.

Resolution LP.3(4) 2009: transboundary CO2 export (provisional 2019)

Protocol Article 6 as originally adopted in 1996 prohibited the export of wastes to other countries for dumping or incineration at sea. As North Sea and other regional CCS architectures matured, it became clear that cross-border movement of CO2 streams (e.g., from a continental European emitter to a Norwegian or United Kingdom sub-seabed reservoir) would be an important operational use case, but Protocol Article 6 as drafted prohibited the cross-border transfer.

The Fourth Meeting of Contracting Parties in October 2009 adopted Resolution LP.3(4) amending Protocol Article 6 to add a new paragraph 2 permitting export of CO2 streams for sub-seabed sequestration if (i) an agreement or arrangement has been entered into by the countries concerned including confirmation and allocation of permitting responsibilities; (ii) in the case of export to a non-Contracting Party, the agreement or arrangement provides for not less than the protection accorded by the Protocol; and (iii) the Contracting Parties to the Protocol provide notification of the agreement or arrangement to the IMO secretariat.

The 2009 amendment is to Article 6 of the Protocol, which is a substantive Protocol provision rather than an Annex, and accordingly required ratification by two-thirds of contracting parties to enter into force under Protocol Article 21. By 2019 the two-thirds threshold remained unmet (only approximately one-quarter of parties had ratified by that point), and the Fourteenth Meeting of Contracting Parties in October 2019 adopted Resolution LP.5(14) providing for provisional application of the Article 6 amendment by parties that have deposited a declaration of provisional application with the IMO secretariat. As of 2026 the provisional-application route is in operation between approximately fifteen parties including the United Kingdom, Norway, Denmark, the Netherlands, Belgium and Sweden, and is the legal predicate for the live North Sea cross-border CCS architecture.

Resolution LP.4(8) 2013 marine geoengineering: not yet in force

Building on the 2008 ocean-fertilization architecture, the Eighth Meeting of Contracting Parties in October 2013 adopted Resolution LP.4(8) amending the Protocol to add a new Article 6bis (“Marine Geoengineering”) and a new Annex 4 (“Marine Geoengineering Activities”) and Annex 5 (“Assessment Framework for Marine Geoengineering Activities”). The amendment would prohibit marine geoengineering activities listed in Annex 4 unless authorised under a permit issued in accordance with Annex 5. As initially adopted, Annex 4 lists only ocean fertilization, but the framework is structured to permit additional listings as the science and policy on marine geoengineering activities such as ocean alkalinity enhancement, ocean afforestation, deep-sea CCS and others mature.

As of 2026 the LP.4(8) 2013 amendment has not entered into force. The amendment is to substantive Protocol provisions and accordingly requires ratification by two-thirds of contracting parties under Protocol Article 21. Approximately twelve parties have ratified as of 2026, well below the thirty-six-party threshold. The slow ratification pace reflects the contested politics of marine geoengineering, the limited operational urgency in the absence of large-scale ocean-CDR commercial deployment, and the parallel availability of the 2008 ocean-fertilization architecture for the most acute case.

North Sea CCS architecture: LP.1(1) and LP.3(4) in operational practice

The North Sea is the world’s most operationally advanced sub-seabed CCS region and the primary test bed for both the LP.1(1) 2007 in-force framework and the LP.3(4) 2009 provisional-application regime. As of 2026, four projects illustrate how the London Protocol frameworks interact with national permit systems.

Sleipner (Norway, Equinor) has injected CO2 stripped from natural gas production into the Utsira Formation saline aquifer at approximately 800 metres depth in the Norwegian North Sea sector since 1 October 1996. The project pre-dates LP.1(1) by eleven years; the Norwegian permit regime under the Petroleum Act 1996 was adapted to comply retroactively with the LP.1(1) guidelines after the 2007 amendment. Annual injection volume is approximately 0.9 million tonnes. No significant leakage has been detected across three decades of seismic monitoring.

Snøhvit (Norway, Equinor) injects CO2 from the Hammerfest LNG terminal into the Tubåen Formation at 2,600 metres depth in the Barents Sea, with annual injection of approximately 0.7 million tonnes since 2008. The Snøhvit permit was structured under the Norwegian CO2 Storage Regulations 2014, which implement LP.1(1) alongside EU CCS Directive 2009/31/EC.

Northern Lights (Norway, Equinor/Shell/TotalEnergies) is the first project designed to receive CO2 from multiple international emitters via ship transport and inject it into the Johansen Formation at approximately 2,600 metres depth in the Norwegian North Sea. Phase 1, with a designed injection capacity of 1.5 million tonnes per year, accepted its first CO2 shipment from a Belgian industrial emitter in 2024. The project operates under the LP.3(4) provisional-application framework: the United Kingdom, Belgium, Denmark and the Netherlands have each filed declarations of provisional application under Resolution LP.5(14), and bilateral agreements between Norway and each exporting state satisfy the LP.3(4) Article 6(2) conditions.

Acorn (United Kingdom, Storegga) is developing CO2 injection into the Captain Sandstone aquifer in the UKCS from the St Fergus gas terminal in Aberdeenshire, with environmental permitting progressing under the UK Offshore Petroleum Regulator for Environment and Decommissioning (OPRED) and the Offshore Storage Regulations 2010. The Acorn project is structured to receive CO2 from continental European emitters under the LP.3(4) provisional regime once export pipeline infrastructure from continental Europe is commissioned.

These four projects share a common governance structure: national storage permit keyed to LP.1(1) site characterisation and monitoring requirements, bilateral government-to-government agreement for cross-border CO2 under LP.3(4), IMO notification of the agreement or arrangement under LP.3(4) paragraph 2(c), and annual monitoring and reporting to both the national competent authority and the LC/LP secretariat. The Northern Lights Phase 1 operational record through 2024 to 2026 is the first empirical test of the cross-border provisional regime at commercial scale.

2024 ocean-CDR submissions to IMO LC/LP

Through the early 2020s, scientific and commercial interest in ocean carbon dioxide removal (ocean-CDR) has grown rapidly under the pressure of net-zero policy commitments and the recognition that conventional emission reductions alone will not meet 1.5 to 2.0 degree Celsius temperature goals. Commercial proposals have emerged for ocean alkalinity enhancement (large-scale addition of alkaline minerals such as olivine or calcium carbonate to surface waters), ocean afforestation (deployment of macroalgae cultivation systems in open-ocean waters), deep-sea CCS (direct injection of CO2 into deep-water columns or sediments), iron-fertilization variants and others.

The IMO Sub-Committee on Pollution Prevention and Response (PPR) and the Marine Environment Protection Committee (MEPC) have received submissions from contracting parties and observers through 2024 reviewing emerging issues for marine geoengineering and ocean-CDR governance, with the principal substantive thread being the relationship between the 2013 LP.4(8) amendment, the 2008 LC-LP.1 ocean-fertilization architecture, the 2007 LP.1(1) sub-seabed CCS architecture and the 2009 LP.3(4) transboundary export architecture, on the one hand, and the operational need to assess and authorise (or prohibit) novel ocean-CDR activities, on the other. The 2024 LC/LP joint scientific advisory work has been the primary venue for this regulatory governance development.

Iron fertilization, alkalinity enhancement, ocean afforestation, deep-sea CCS

The four principal ocean-CDR pathways under London-regime scrutiny are: iron fertilization, addressed through the 2008 ocean-fertilization architecture and prohibited for commercial purposes; ocean alkalinity enhancement, addressed through the LP.4(8) 2013 marine-geoengineering framework once in force, and currently under PPR/MEPC review for case-by-case scientific-research permits; ocean afforestation including macroalgae cultivation and deployment, addressed similarly under LP.4(8) once in force; and deep-sea CCS (direct CO2 injection into deep water columns or sediments rather than sub-seabed geological formations), which falls outside the LP.1(1) sub-seabed framework and therefore remains prohibited under the Protocol Annex 1 reverse list as of 2026.

The scientific assessment of these pathways is the principal work programme of the LC/LP Joint Scientific Group through the mid-2020s, with annual reports reviewing efficacy, durability of carbon storage, scale-up potential, ecological side-effects, monitoring and verification protocols, and governance recommendations. The work integrates with the parallel scientific assessment by the Intergovernmental Panel on Climate Change Working Group III on ocean-CDR options, the Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) Working Group 41, and the United Nations Decade of Ocean Science for Sustainable Development programme.

UNCLOS Article 210 implementation linkage

UNCLOS Article 210 (“Pollution by dumping”) sets out the global-treaty obligation for states to adopt laws and regulations to prevent, reduce and control pollution of the marine environment by dumping, and provides that “national laws, regulations and measures shall be no less effective in preventing, reducing and controlling such pollution than the global rules and standards.” The “global rules and standards” referenced in Article 210 are universally understood to be the London Convention 1972 and the 1996 Protocol, making the London regime the primary global instrument implementing UNCLOS Article 210.

The UNCLOS Article 210 reference architecture has three operational consequences. First, it elevates LC/LP rules to the status of UNCLOS-incorporated minimum standards, applicable in principle even to states that are party to UNCLOS but not to LC/LP. Second, it creates a treaty-law obligation for LC/LP rules to be at least as stringent as the relevant UNCLOS framework provisions. Third, it interlocks LC/LP enforcement with the broader UNCLOS Part XII architecture on protection of the marine environment, including the Article 211 vessel-source pollution rules, the Article 212 atmospheric pollution rules and the Article 213 enforcement provisions.

The UNCLOS Article 210 reference is paralleled in equivalent provisions of regional treaties including the OSPAR Convention, the Helsinki Convention, the Barcelona Convention and the Bucharest Convention, all of which incorporate the LC/LP rules as the regional benchmark.

Relationship to MARPOL (dumping vs operational)

The London regime addresses deliberate disposal at sea of wastes and other matter; the MARPOL Convention addresses operational pollution from ships in the course of normal navigation, cargo operations and ship management. The two regimes are complementary and non-overlapping in principle, but the operational boundary requires careful attention in three edge cases.

Cargo residues. Under MARPOL Annex I and MARPOL Annex I Regulation 15 discharge control, oil and oily-water mixture discharge from ships is governed by MARPOL operational discharge criteria, not by London. Cargo wash water and cargo-tank cleaning residues are MARPOL operational discharges, not London dumping. The London regime captures only the deliberate disposal of wastes generated outside the normal operation of the ship.

Garbage and sewage. MARPOL Annex IV governs sewage discharge from ships in normal operation, and MARPOL Annex V governs garbage discharge from ships in normal operation. London Annex 1 category 2 (sewage sludge) addresses bulk shore-generated sewage sludge transported to sea for dumping, not operational ship-source sewage; London does not address operational ship-source garbage at all.

Sunken vessels. The deliberate disposal of vessels and platforms at sea is London Annex 1 category 4 (subject to permit) and is permitted only after pre-disposal characterisation, alternatives assessment, environmental impact assessment and post-disposal monitoring. Accidental sinking is not London “dumping” but is governed by the Hong Kong Convention on safe and environmentally sound ship recycling for the recycling pathway and by the salvage and wreck-removal regime (Nairobi Convention 2007) for the wreck-removal pathway.

The London/MARPOL boundary is also relevant for Ballast Water Management Convention compliance: ballast water is operational ship-source pollution under BWM, not London dumping. Similarly, Polar Code Part II discharge restrictions in Antarctic Special Areas are MARPOL Special Area rules, not London rules.

Relationship to OSPAR Annex II + Helsinki Annex III

The OSPAR Convention 1992 Annex II (“Prevention and Elimination of Pollution by Dumping or Incineration”) implements LC/LP for the North-East Atlantic and is more stringent than LC/LP in certain respects, notably the OSPAR Decision 98/3 prohibition on the deep-water disposal of decommissioned offshore platforms (subject to limited derogations), which goes beyond London Annex 1 category 4. OSPAR Annex II also incorporates the OSPAR Action Lists for dredged-material assessment, which are stricter than the LP Annex 2 minimum framework.

The Helsinki Convention 1992 Annex III (“Criteria and Measures Concerning the Prevention of Pollution from Land-Based Sources”) and Annex IV (“Prevention of Pollution from Ships”) together cover the Baltic Sea and impose a near-total dumping prohibition, with limited exceptions for dredged material. The Helsinki framework is the most stringent regional dumping regime globally.

The Barcelona Convention 1976/1995 Dumping Protocol of 1976 (in force 1978, replaced by the 1995 Protocol in force 2008) implements LC/LP for the Mediterranean and the Cartagena Convention 1983 LBS Protocol of 1999 (in force 2010) implements LC/LP for the Wider Caribbean Region alongside the SPAW Protocol 1990. Equivalent regional implementations exist under the Abidjan Convention 1981 for the West and Central African coast, the Nairobi Convention 1985 for the Western Indian Ocean, the Jeddah Convention 1982 for the Red Sea and Gulf of Aden, the Kuwait Convention 1978 for the ROPME sea area, the Lima Convention 1981 for the South-East Pacific, the Antigua Convention 2002 for the North-East Pacific, the Noumea Convention 1986 for the South Pacific, and the Tehran Convention 2003 for the Caspian Sea.

The regional architecture is formally subordinate to LC/LP under the Article 3(4) “more stringent measures” savings clause, and operationally interconnects with LC/LP through joint scientific work, joint capacity-building programmes and joint reporting.

Dredged material: ~80% of permitted dumping by volume

Dredged material is the largest single category of permitted dumping under LC/LP. It comprises the sediment removed from harbour basins, navigation channels, river mouths and coastal-engineering project sites by mechanical (clamshell, backhoe), hydraulic (cutter-suction, trailing-suction-hopper) or hybrid dredgers, and is subsequently transported to designated disposal sites for relocation.

The eighty-percent share by global volume is consistent across the LC/LP joint scientific reports through the 2010s and 2020s, with the share occasionally rising to ninety percent in particular years dominated by major dredging campaigns. The next-largest categories are inert geological material from coastal engineering and bulky-items disposal in island contexts; sewage sludge dumping has effectively ceased in most contracting parties since the 1998 EU prohibition.

The dredged-material category covers a wide spectrum of sediment types. Clean sediment from estuarine and coastal channel maintenance is typically returned to nearshore disposal sites or used for beneficial uses such as beach nourishment and habitat restoration. Contaminated sediment from harbour basins with industrial and urban catchments may carry significant burdens of metals (lead, zinc, copper, mercury, cadmium), tributyltin (TBT, a legacy antifouling biocide), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides and other persistent organic pollutants. The action-list assessment is keyed to these contaminants and disposal eligibility is contingent on the sediment falling below the upper action-level thresholds.

Major disposal sites: Bristol Channel, Tokyo Bay, SF Bay, Singapore

Operational dredged-material disposal sites are designated by national competent authorities under LC/LP-keyed permit frameworks. Notable long-running disposal sites include:

The Bristol Channel and Severn Estuary disposal sites in the United Kingdom, supporting maintenance dredging of the Bristol, Cardiff, Newport, Swansea and Avonmouth port basins, with site characterisation through the Cefas (Centre for Environment, Fisheries and Aquaculture Science) and permit issuance by the Marine Management Organisation (England) and Natural Resources Wales (Wales).

Tokyo Bay and Yokohama disposal sites in Japan, supporting maintenance dredging of the Tokyo, Yokohama, Kawasaki, Chiba and adjacent port basins, with permit issuance by the Japanese Ministry of Land, Infrastructure, Transport and Tourism and the Ministry of the Environment.

San Francisco Bay disposal sites in the United States, supporting maintenance dredging of the Port of Oakland, Port of San Francisco, Richmond, Stockton and Sacramento port basins, with permit issuance under the Marine Protection, Research, and Sanctuaries Act 1972 (MPRSA, Title I “Ocean Dumping Act”) by the United States Environmental Protection Agency with concurrence from the United States Army Corps of Engineers.

Singapore Strait disposal sites supporting maintenance dredging of the Port of Singapore, the largest container transhipment port globally, with permit issuance by the Maritime and Port Authority of Singapore (MPA) and the National Environment Agency (NEA).

Additional notable disposal sites include the Hamburg Outer Elbe disposal sites (Germany), the Rotterdam Maasvlakte disposal sites (Netherlands), the Antwerp Western Scheldt disposal sites (Belgium), the Marseille Fos disposal sites (France), the Shanghai Yangshan disposal sites (China), the Ningbo-Zhoushan disposal sites (China), the Pusan disposal sites (Republic of Korea), the Mumbai Outer Channel disposal sites (India) and the Houston Ship Channel disposal sites (United States).

National permit framework: characterisation + EIA + monitoring

The typical national permit framework under LC/LP follows a four-stage architecture aligned with the Protocol Annex 2 assessment requirements. Stage 1: pre-disposal characterisation of the dredged material, including bulk geotechnical properties (grain size, water content, plasticity), bulk geochemical properties (organic carbon, sulfide, redox potential), action-list contaminant suite (metals, organics, biocides, persistent organic pollutants), bulk biological properties (bioassay testing on amphipod, bivalve and fish endpoints) and operational parameters (estimated volume, dredging method, scheduling).

Stage 2: alternatives assessment, reviewing waste prevention at source (catchment-source-control measures), beneficial-use options (beach nourishment, habitat restoration, industrial use, capping for contaminated-site remediation), upland disposal options (confined disposal facilities, landfill) and alternative aquatic disposal options (alternative disposal sites with different characteristics). The “no other practicable solution” rule requires the proponent to demonstrate that the proposed disposal is the most environmentally appropriate option after the alternatives review.

Stage 3: environmental impact assessment for the proposed disposal, including a quantitative dispersal model (passive plume tracking, near-field dispersion modelling), a benthic impact assessment (community structure pre-disposal and projected post-disposal, recovery time estimates), a water-quality impact assessment (turbidity, dissolved oxygen, contaminant flux), a fisheries-impact assessment, a navigation and other-uses impact assessment and a cumulative-impacts assessment with adjacent disposal activity.

Stage 4: post-disposal monitoring, including periodic bathymetric survey of the disposal mound, periodic benthic community survey at the disposal site and reference sites, periodic sediment chemistry survey and periodic biological tissue contaminant survey. Monitoring data feed back into action-list refinement, site-management plans and future permit assessments.

IMO Specific Guidelines for Dredged Material (LC/SG)

The LC/LP joint scientific group has developed a full set of Specific Guidelines under the Protocol Annex 2 framework, including the Specific Guidelines for Assessment of Dredged Material. The dredged-material guidelines, developed iteratively through the 1990s, 2000s and 2010s under the work of the LC/LP Scientific Group through annual sessions, set out detailed technical and procedural rules for the four-stage permit framework summarised above and provide a reference benchmark for national permit frameworks.

The dredged-material guidelines integrate with the OSPAR Guidelines for the Management of Dredged Material at Sea (2014, with periodic updates), the Helsinki Commission HELCOM Guidelines for Dumping of Dredged Material (2007), and equivalent regional guidelines for the Mediterranean (Barcelona Dumping Protocol Guidelines), the Wider Caribbean Region (Cartagena LBS Protocol Guidelines), and the South-East Pacific (Lima Convention guidelines). The convergence between the LC/LP and regional guidelines is high but not complete, reflecting differences in regional contaminant priorities, sediment compositions and ecological sensitivities.

Additional Specific Guidelines under LC/LP cover assessment of vessels (Annex 1 category 4), assessment of inert inorganic geological material (category 5), assessment of organic material of natural origin (category 6), assessment of bulky items (category 7), assessment of CO2 streams for sub-seabed sequestration (the 2007 guidelines under LP.1(1)) and assessment under the marine-geoengineering framework (the 2010 framework for ocean-fertilization scientific research and the framework anticipated for LP.4(8) once in force).

“Operation Hat” 1960s historical nerve agent dumping context

The London Convention’s emergence in 1972 was driven in part by acute public concern at deliberate ocean disposal of chemical-weapon stockpiles. Operation Hat was a series of nerve-agent disposal operations conducted by the United States Army Chemical Corps in the central Pacific Ocean between 1964 and 1968, in which surplus VX, sarin (GB) and mustard agent munitions were loaded onto retired Liberty-ship hulks and scuttled in deep water. The parallel Operation CHASE (Cut Holes And Sink ‘Em) programme, conducted between 1967 and 1970, scuttled at least four hulks loaded with nerve and conventional munitions off the Atlantic seaboard of the United States.

The Operations were exposed in detail by United States congressional inquiries in 1969 and by international press coverage in 1969 and 1970, generating bipartisan public revulsion in the United States and analogous reactions in other nuclear-armed and chemical-weapon-stockpiled states (the Soviet Union, the United Kingdom and France had analogous historical disposal operations). The Stockholm Conference Recommendation 86 was an explicit response to the chemical-weapon dumping disclosures, and the 1972 London Convention Annex I prohibition on dumping of “materials produced for biological and chemical warfare” was the operational treaty-law response.

The Operation Hat and Operation CHASE disposal sites have been the subject of intermittent monitoring and recovery assessment through the 1980s, 1990s and 2000s. Most sites have not been remediated; the operational policy assumption has been that deep-water disposal in stable geological settings provides adequate long-term containment, with the principal monitoring concern being the structural integrity of the steel hulks over multi-decadal time scales.

Outer Space Treaty 1967 Article IV analogy

A doctrinal parallel exists between the London Convention prohibition on dumping of high-level radioactive waste at sea and the Outer Space Treaty 1967 Article IV prohibition on placing nuclear weapons or any other kinds of weapons of mass destruction in outer space. The Outer Space Treaty entered into force on 10 October 1967, five years before the London Convention, and was negotiated under the same UN-system multilateral diplomacy that produced the Stockholm Conference and the London regime.

Both prohibitions reflect the policy intuition that shared global commons (the high seas under London, outer space under the Outer Space Treaty) require categorical prohibitions on the most acutely hazardous categories of disposal or deployment, regardless of the technical feasibility of containment, because the global-commons character of the relevant environment makes case-by-case risk assessment unworkable. The intuition has been extended in subsequent decades to the Antarctic Treaty 1959 prohibition on military activities, the Moon Agreement 1979 prohibitions on weapons in lunar orbit, the Comprehensive Nuclear-Test-Ban Treaty 1996 and various regional nuclear-weapon-free-zone treaties.

The Outer Space Treaty/London Convention parallel is not legally binding cross-reference (the two regimes are formally distinct) but the doctrinal parallel has been recurrently invoked in academic and policy discussion of the global-commons protection architecture.

National implementation frameworks: US, UK, Australia, Canada, Japan

Five national permit frameworks illustrate the range of LC/LP implementation across contracting parties.

United States. The United States is party to the 1972 London Convention but has not ratified the 1996 Protocol. The domestic framework is the Marine Protection, Research, and Sanctuaries Act 1972 (MPRSA), Title I (Ocean Dumping Act), codified at 33 U.S.C. sections 1411-1421. EPA issues general permits for dredged material in coordination with the Army Corps of Engineers under Section 103 of MPRSA; the Corps of Engineers administers the permit programme. The MPRSA prohibition list (Section 102) maps broadly to the 1972 Annex I black list, and the EPA action levels for dredged material assessment are functionally equivalent to the LP Annex 2 action lists. The United States applies the “no other practicable option” test for dredged-material permits as a matter of administrative practice even without formal Protocol obligation. EPA and the Army Corps of Engineers publish joint technical guidance for ocean disposal of dredged material (the Green Book, 2004) updated periodically.

United Kingdom. The UK is party to both the 1972 Convention and the 1996 Protocol and has ratified both. The Marine and Coastal Access Act 2009 Part 4 (marine licensing) replaced the Food and Environment Protection Act 1985 Part II as the licensing statute. The Marine Management Organisation (MMO) in England, Marine Scotland, Natural Resources Wales and the Northern Ireland Environment Agency issue marine licences for disposal at sea. The MMO applies the LP Annex 2 framework directly through its internal guidance. For offshore platforms and structures, OSPAR Decision 98/3 applies via the OSPAR Act 1997 implementing legislation, overlaying the London Annex 1 category 4 analysis with the more restrictive OSPAR derogation test. For CO2 sequestration, the Offshore Petroleum Production and Pipelines (Assessment of Environmental Effects) Regulations 1999 and the Energy Act 2008 as amended by the Energy Act 2023 provide the storage licensing framework, cross-referenced to the LP.1(1) guidelines through the OPRED permit process.

Australia. Australia is party to the 1996 Protocol. The Environment Protection (Sea Dumping) Act 1981 (Commonwealth) governs ocean dumping, administered by the Department of Climate Change, Energy, the Environment and Water (DCCEEW). The Act was amended in 2010 to incorporate LP.1(1) and to explicitly permit CO2 sequestration permits. The DCCEEW has published LP Annex 2-aligned guidelines for dredged material assessment (2009, updated 2016). Australia’s domestic dredging industry includes major port maintenance programmes at Sydney, Melbourne, Brisbane, Fremantle and Darwin, all permitted under the Sea Dumping Act framework.

Canada. Canada is party to both instruments. The Canadian Environmental Protection Act 1999 (CEPA), Part 7, Division 3 governs ocean dumping, administered by Environment and Climate Change Canada (ECCC). ECCC publishes guidelines for ocean disposal of dredged material that align closely with the LP Annex 2 framework. Canadian permit volumes are dominated by dredged material from the ports of Vancouver, Prince Rupert, Montreal, Halifax, Saint John and the St Lawrence Seaway. The ECCC permit programme includes mandatory monitoring at disposal sites and a national disposal-at-sea database published annually.

Japan. Japan is party to the 1996 Protocol. The Law Relating to the Prevention of Marine Pollution and Maritime Disaster 1970 (Marine Pollution Prevention Act), administered by the Ministry of the Environment (MOE) and the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), governs ocean dumping. Japan’s dredged-material permit volumes are among the largest in Asia, reflecting intensive port maintenance at Tokyo Bay, Osaka Bay, Nagoya, Yokohama, Kobe and other major ports. MOE and MLIT apply action lists for contaminant screening in dredged material that are aligned with but not identical to the LP Annex 2 framework; Japan has periodically submitted national experience to the LC/LP Scientific Group to inform guideline revision.

Permit system: consultative meeting + scientific group + compliance group

The LC/LP institutional architecture comprises five principal organs. The Consultative Meeting of Contracting Parties (LC) under the 1972 Convention adopts amendments and resolutions for the 1972 instrument; the Meeting of Contracting Parties (LP) under the 1996 Protocol adopts amendments and resolutions for the Protocol; both bodies have met jointly each autumn at IMO Headquarters since the early 2000s, with consolidated agenda and consolidated reporting.

The Joint Scientific Group (SG) combines the 1972 Convention Scientific Group and the 1996 Protocol Scientific Group, meets annually each spring (typically hosted by a contracting party), and provides scientific advice to the autumn LC/LP meetings. The Scientific Group has approximately twenty active national delegations and a rolling intersessional working programme on dredged material, vessels and platforms, ocean-CDR, marine geoengineering, sub-seabed CCS, monitoring frameworks and emerging issues.

The Compliance Group under Protocol Article 11 assesses Protocol parties’ compliance with reporting and substantive obligations on a facilitative, non-adversarial basis. The Compliance Group has reviewed compliance issues across the 1996 Protocol parties through annual sessions since 2008 and has issued recommendations to individual parties and to the Meeting of Parties on systemic compliance challenges including reporting gaps, permit-issuance gaps and post-disposal monitoring gaps.

The Office for the London Convention and Protocol (OLCP) within the IMO Marine Environment Division provides administrative, scientific and legal support to all three bodies. National competent authorities in each contracting party administer the domestic permit system: the United States Environmental Protection Agency under the MPRSA, the United Kingdom Marine Management Organisation under the Marine and Coastal Access Act 2009, the Australian Department of Climate Change Energy the Environment and Water under the Environment Protection Sea Dumping Act 1981, the Canadian Environment and Climate Change Canada under the Canadian Environmental Protection Act 1999, the Japanese Ministry of the Environment under the Marine Pollution Prevention Act, and equivalent ministries elsewhere.

2024 ocean-CDR scientific advisory work

Through 2024 the LC/LP Joint Scientific Group has prioritised three substantive work streams. First, ocean alkalinity enhancement: detailed review of olivine, calcium carbonate and brucite mineral addition pathways, including efficacy assessment, durability of carbon storage, ecological side-effects (alkalinity-driven calcification effects on planktonic organisms, trace-metal release from olivine weathering, secondary nutrient effects), monitoring and verification requirements and governance recommendations.

Second, ocean afforestation and macroalgae cultivation: review of large-scale macroalgae cultivation proposals (notably the Sargassum and Macrocystis commercial proposals), including efficacy assessment, durability of carbon storage in deep-sea sinking pathways, ecological side-effects (impacts on pelagic food webs, deep-sea benthic communities, oxygen demand from sinking biomass) and governance recommendations.

Third, deep-sea CCS assessment: review of direct CO2 injection into deep-water columns and sediments, distinguishing this from the LP.1(1) sub-seabed geological-formation framework and considering whether deep-sea CCS could be brought within the Protocol Annex 1 list (currently excluded by the requirement for sub-seabed geological injection) or under the marine-geoengineering framework (LP.4(8) Annex 4 listing) once in force.

The 2024 SG report fed into the 2024 autumn LC/LP meetings and into the 2025 PPR/MEPC discussion on emerging issues for marine environmental governance. The 2026 SG agenda is expected to extend the assessment to additional ocean-CDR pathways including artificial upwelling, marine biomass sinking and ocean-based direct air capture.

Class society + flag-state PSC inspection of permits/manifests

Classification societies are not directly regulated under LC/LP, which addresses states’ obligations rather than vessel certification. However, the major class societies including DNV, Lloyd’s Register, ABS (American Bureau of Shipping), Bureau Veritas and ClassNK provide environmental impact assessment, marine sediment characterisation, dredged-material analysis and CCS site characterisation services to operators preparing LC/LP permit submissions. DNV in particular is a major provider of CCS site characterisation and monitoring services in the North Sea CCS architecture, including through its Energy Systems advisory practice and its Maritime and Oil and Gas Class divisions.

Port-state-control (PSC) and flag-state inspection under the Paris MoU, the Tokyo MoU, the Caribbean MoU, the Indian Ocean MoU, the Mediterranean MoU and the other regional PSC MoUs include verification of LC/LP-keyed permits and manifests when vessels call at ports for loading or discharge of materials destined for sea disposal. The PSC regime is operationally most relevant for dredged-material carriers (trailing-suction hopper dredgers and split-barge configurations) departing port for disposal at designated dumping sites, decommissioned offshore platforms under tow for sub-seabed disposal under London Annex 1 category 4, and CO2 carriers loaded for cross-border transport to sub-seabed sequestration reservoirs under the LP.3(4) provisional architecture.

PSC inspectors verify the operator’s possession of the relevant national permit, the permit’s currency and scope coverage, the consistency of the cargo manifest with the permit terms (volume, composition, destination), the operational condition of the vessel and its discharge or transfer equipment, and the master’s familiarity with the permit conditions and reporting obligations. Non-compliance findings can result in detention of the vessel under the PSC MoU procedures pending rectification, with reporting to the flag state and to the IMO PSC database.

2030 outlook: marine geoengineering framework + CCS expansion

The 2026 to 2030 outlook for the LC/LP regime is dominated by four interrelated developments. First, the entry into force of the LP.4(8) 2013 marine-geoengineering amendment, which requires ratification by two-thirds of contracting parties (approximately thirty-six of the current fifty-three Protocol parties) and is currently approximately one-third of the way to the threshold. The pace of ratification through the late 2020s will determine whether the framework enters into force before 2030 or slips into the 2030s.

Second, the continued expansion of the cross-border sub-seabed CCS architecture under the LP.3(4) 2009 provisional-application route, with several additional parties expected to join the provisional regime through 2027 to 2029 and the eventual entry into force of the formal LP.3(4) amendment as ratifications accumulate. The North Sea CCS architecture between the United Kingdom, Norway, Denmark, the Netherlands, Belgium and Sweden is the operational test case; equivalent architectures are in early planning in the Mediterranean (between France, Italy, Spain and Algeria), in Asia (between Japan, the Republic of Korea, Australia and Indonesia) and in the Gulf of Mexico (between the United States and Mexico).

Third, the operational test of the LP.4(8) marine-geoengineering framework against actual ocean-CDR deployment proposals through the late 2020s, with several commercial ocean alkalinity enhancement and ocean afforestation projects in early permitting in the Republic of Korea, Iceland, Australia and the United States. The LC/LP framework will be the principal global benchmark even for non-Protocol-party states, given the UNCLOS Article 210 incorporation.

Fourth, accession by major non-parties (the United States, the Russian Federation, China, India, Brazil, Indonesia and others), which is the principal political and operational limit on the global reach of the Protocol regime. United States Senate consent to the 1996 Protocol has been pending since the 1998 signature and remains uncertain through the 2026 to 2030 horizon, although United States domestic implementation under the MPRSA is broadly Protocol-equivalent in operational practice.

Limitations

The London Convention 1972 and the 1996 London Protocol operate within six documented limits that practitioners should account for.

Jurisdictional gaps from non-ratification. The 1996 Protocol’s fifty-three parties represent a minority of IMO member states. Major maritime economies including the United States, the Russian Federation, China, India, Brazil, Argentina, Indonesia, Malaysia, Thailand and Singapore are not Protocol parties. Enforcement of the Protocol’s stricter reverse-list rules against vessels or operators from non-party states depends on flag-state and port-state jurisdiction under the UNCLOS Article 210 residual framework, not direct Protocol application.

LP.4(8) not in force. The 2013 marine geoengineering amendment, which would govern ocean alkalinity enhancement, ocean afforestation, deep-sea CCS and similar emerging ocean-CDR activities under a binding permit framework, has not entered into force as of 2026. Commercial ocean-CDR proponents operate under the non-binding 2008 ocean-fertilization architecture and case-by-case scientific-research permit assessments. The absence of a binding framework creates regulatory uncertainty for commercial-scale ocean-CDR projects.

Sub-seabed only for CO2 sequestration. The LP.1(1) 2007 amendment permits CO2 streams for sub-seabed geological sequestration only. Direct CO2 injection into the deep-water column or into marine sediments (as distinct from geological formations below the seabed) remains prohibited. This restriction limits the LP.1(1) pathway to projects with access to suitable sub-seabed geological storage reservoirs, excluding deep-sea direct injection options.

Monitoring duration mismatches. Sub-seabed CCS storage operates on centuries-to-millennia time scales. Current LC/LP permit monitoring requirements use multi-year to multi-decade horizons. The mismatch between the time scale of storage integrity and the institutional time scale of permit monitoring is not addressed in the existing LP.1(1) guidelines.

Reporting and compliance gaps. The Protocol Compliance Group has documented systemic reporting gaps among several contracting parties, including incomplete returns of annual permit and dumping activity data under Article 9. The data gaps reduce the reliability of global dredged-material dumping volume estimates and limit the secretariat’s ability to assess cumulative impacts across disposal sites.

Definitional boundary with MARPOL. The London/MARPOL jurisdictional boundary (deliberate disposal vs operational discharge) is clear in principle but requires careful assessment in edge cases involving bulk cargo residues, fish-processing effluent from factory vessels, drill cuttings and produced water from offshore platforms, and desalination brine from newbuilding vessels. National competent authorities apply the boundary differently in some cases, creating inconsistent permit practice across contracting parties.

See also

• MARPOL Convention
• MARPOL Annex I
• MARPOL Annex I Regulation 15 discharge control
• OSPAR Convention 1992
• Helsinki Convention 1992
• Bucharest Convention 1992
• Barcelona Convention 1976/1995
• Cartagena Convention 1983
• Abidjan Convention 1981
• Nairobi Convention 1985
• Jeddah Convention 1982
• Kuwait Convention 1978
• Lima Convention 1981
• Antigua Convention 2002
• Noumea Convention 1986
• Tehran Convention 2003
• Ballast Water Management Convention
• Hong Kong Convention
• Polar Code
• Antarctic Special Area and Polar Code
• Calculator catalogue

References

References include the IMO Office for the London Convention and Protocol portal, the consolidated text of the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972 as amended through 2006, the consolidated text of the 1996 Protocol as amended through 2006, the IMO London Protocol CO2 sub-seabed sequestration framework documentation under Resolutions LP.1(1) (adopted 3 November 2006, in force 10 February 2007) and LP.3(4) of 2009 (provisional application from 2019 under Resolution LP.5(14)), the IMO London Protocol marine geoengineering and ocean fertilization documentation under Resolutions LC-LP.1(2008) and LP.4(8) of 2013 (not yet in force), Resolution LC.51(16) of 1993 phasing out radioactive waste sea disposal, the United Nations Convention on the Law of the Sea Article 210 dumping provisions, the OSPAR Convention 1992 and its Annex II, the Helsinki Convention 1992 and its Annex III, the IMO Marine Environment Division programme of work, the IMO Specific Guidelines for Assessment of Dredged Material, the LC/LP Joint Scientific Group annual reports through 2024, the LC/LP Compliance Group reports under Protocol Article 11, and the principal national permit frameworks (United States MPRSA Title I, United Kingdom Marine and Coastal Access Act 2009, Australian Sea Dumping Act 1981, Canadian CEPA 1999 Part 7 Division 3, Japanese Marine Pollution Prevention Act). Full citation links appear in the frontmatter.

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