The London Protocol was introduced in 1996 to modernise and eventually replace the “Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, 1972″, also known as the London Convention. The Protocol was developed and agreed to by the International Maritime Organisation (IMO) and entered into force in 2006. It introduced a ‘reverse list’ approach, which outlines wastes and other matters that can be considered for dumping. Carbon dioxide used to be excluded from this list.

The London Protocol is of high significance for carbon dioxide removal, as it provides the international legal basis for sub-seabed geological storage of CO₂ and for transboundary CO₂ transport in international marine environments. The London Protocol also regulates marine geoengineering, which includes ocean fertilisation.

As the result of an amendment to the Protocol adopted in 2006, carbon dioxide is one of the wastes that can be considered for dumping in marine environments under specific conditions. This amendment provided the legal basis in international law for CO₂ sequestration in sub-seabed geological formations and entered into force in 2007.

Until recently, the transboundary transport of CO₂ for the purposes of sub-seabed geological storage was prohibited by the Protocol. A legal solution was found in 2019, allowing individual parties to the Protocol to opt in and get permission to conduct such activities, following an amendment adopted in 2009 still pending entry into force.

Adopted in 1996, the London Protocol replaces the Convention and is built around the precautionary principle. Except for the substances listed in its reverse list in Annex 1, the dumping of any substance is strictly prohibited. When it entered into force in March 2006, the list comprised seven substances, including sewage sludge and dredged material.

Inclusion of CO₂ in the reverse list

A 2006 amendment included CO₂ streams from carbon dioxide capture and sequestration in waste and other forms of dumping materials.  It stipulates that levels of radioactivity shall not be greater than those specified in the Protocol, the CO₂ captured must be disposed of in sub-seabed geological formations, the stream must consist overwhelmingly of CO_2, and no wastes or other matters can be added for the purpose of disposing.

Transborder transport of CO₂

In the initial text of the Protocol, Article 6 prohibited the export to other countries of all substances for dumping or incineration at sea. In 2009, Norway submitted an amendment proposal to allow the export of CO₂ streams for disposal in sub-seabed geological formations, provided that an agreement or arrangement is made between the countries concerned. This amendment was adopted in late 2009. However, it has yet to enter into force as of August 2023, as fewer than two-thirds of the parties to the Protocol have ratified it so far. The countries that have ratified it are Norway, the UK, the Netherlands, Iran, Finland, Estonia, Sweden, Belgium, Denmark and the Republic of Korea. Germany and France are in the process of ratifying the amendment.

To avoid this legislative roadblock, Norway and the Netherlands co-filed a resolution to allow the provisional application of the 2009 amendment. They claimed that the EU CCS Directive provided sufficiently strong protection for human health and environmental safety. This resolution was adopted in 2019, meaning that two countries or more can now export CO₂ for sub-seabed geological storage, provided that they have ratified the Article 6 amendment and submitted a formal declaration of provisional application to the IMO. The first bilateral arrangement was signed between Belgium and Denmark on 26 September, 2022. Several other European countries have signalled their willingness to adopt such arrangements, such as Norway, the Netherlands, Finland and Switzerland.

Marine geoengineering within the London Protocol

The London Protocol provides one of the few international legal frameworks around marine geoengineering, defined as “a deliberate intervention in the marine environment to manipulate natural processes, including to counteract anthropogenic climate change and/or its impacts, and that has the potential to result in deleterious effects, especially where those effects may be widespread, long-lasting or severe”.

In 2008, parties to the Protocol adopted a resolution to regulate ocean fertilisation, deciding that such activities are against the aims of the Convention and the Protocol unless conducted for legitimate scientific purposes. It also called for the creation of a framework to assess scientific research proposals. In 2013, parties to the Protocol adopted another resolution to provide a regulatory framework not only for ocean fertilisation but for other marine geoengineering activities, such as alkalinity enhancement, seabed rocks mineralisation or deposition of crop wastes on the seabed. Eligible activities are listed in Annex 4 of the resolution, and it currently only consists of ocean mineralisation. Therefore, other types of marine geoengineering are currently prohibited under the London Protocol. It is to be noted that this resolution is non-binding, meaning that parties could choose not to respect it without clear consequences.