Ocean Plastics: Whither a Treaty?

Tallash Kantai, Stephanie Switzer, Graham Hamley and Francesco Sindico

Ocean animal health and marine biodiversity are threatened by plastics. Photo by Naja Bertolt Jensen on Unsplash

In a recent report on human rights and biodiversity, the UN Special Rapporteur on Human Rights and the Environment Prof David Boyd suggested the need for a global treaty to deal with the problem of marine plastics. In this short post, the One Ocean Hub wishes to share some comments from different areas of work in order to contribute to this important policy debate. To that end, the post starts with a few words about marine plastics and the treaty approach.

Marine Plastics and the Treaty Approach

Plastics can be found everywhere in the world. Ocean currents take them with them and will deposit them even on the most remote beaches. In doing so, ocean animal health and marine biodiversity are threatened, and pristine environments ruined, both for the people who live there and for those who may want to visit them. Microplastics do not only pose a threat to ocean dwelling animals, but also to human health, with ingestion of such plastics possible via the food chain.

Over the past number of years, global awareness of the detrimental impacts of marine plastics has increased substantially, with the BBC’s the Blue Planet having a particular effect on public consciousness. Marine pollution was also given particular attention within the context of the UN Sustainable Development Goals (SDGs) with SDG 14.1 setting out the need, ‘by 2025, [to] prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution. With the promulgation of SDG 14.1, it is clear that tackling marine pollution, including marine plastics, is now a top global priority. Furthermore, SDG 12 addresses ‘responsible consumption and production’, and contains a number of specific targets on reducing waste generation through prevention, reduction, recycling, and reuse.

Within academia, some policy circles and indeed, the private sector, one of the options suggested to tackle marine plastics is through the negotiation and adoption of a global treaty. A number of countries, most notably Norway, have spearheaded these efforts and the possible negotiation of a global treaty on marine plastics is now a reality. Indeed, more than two-thirds of UN Member States have expressed an openness to a plastics treaty.

The main aspect that draws academics, policy makers, stakeholders and countries towards a treaty is its potentially encompassing nature. A global framework treaty would, in principle, be flexible enough to capture all stakeholders involved in the marine plastics problem to come together to find a solution. Furthermore, a treaty would provide, at least in theory, a legally binding framework together with a roadmap for stakeholders. While national, regional and international initiatives have attempted to deal with the issue of marine plastics, governance of the issue is at present fragmented, leading to gaps and incoherent and patchy responses. Viewed in these terms, a treaty could, ‘anchor, build upon, and complement existing regional and global voluntary and binding frameworks, allowing them to contribute within their core competencies.’

Public international law

Acknowledging the relevance and importance of treaties in dealing with global matters, it is important also to highlight some initial challenges to a treaty solution for marine plastics that stem from the very nature of public international law and of the marine plastics problem itself. Starting with the latter, plastics is a by-product of oil with a clear identifiable stakeholder on the production side: the petrochemical sector. From a consumption perspective, stakeholders vary in scale from big industrial sectors down to the individual consumers. Furthermore, plastic use in many cases is a fundamental necessity rather than a choice. One need only think of the use of plastics in vaccine delivery or in the PPE currently used to tackle the ongoing COVID-19 pandemic to emphasise this point. In other words, the production and consumption of plastic highlights a wide range of stakeholders. Treaties remain, even in modern international law, mainly an instrument made by States and binding upon States, although they could include obligations for States to regulate and monitor private companies in a more harmonized manner.

A further possible challenge present in the treaty approach is the statement that it will be legally binding and provide a clear normative roadmap for all stakeholders. This is not always the case. Opening an intergovernmental negotiation process will often lead to compromise and in some cases the adoption of vague and ambiguous provisions that can be interpreted in different ways by different treaty parties. This can lead to a lessening of ambition in any treaty text. Furthermore, not all provisions present in a treaty are legally binding, despite a treaty itself being formally legally binding. The legal strength of the Paris Agreement on climate change, to give an example, has been hotly debated among legal scholars, as many argue that many of its provisions are “soft” (non-binding) as opposed to “hard” (binding) law. Furthermore, as one of our authors has observed elsewhere, ‘treaty negotiations take time, and with plastic pollution increasing every day, time is a luxury the planet may not be able to afford.’

In making these general observations, we do not wish to undermine the value and interest of policy-driven channels moving towards a treaty. Instead, we wish to highlight the complexity and limits of international law when dealing with problems like ocean plastics. Before moving to some initial insights from the One Ocean Hub work and research, a further challenge to a treaty approach is possibly the most pressing to effectively deal with marine plastics: lack of information.

Science and public international law

An effective treaty can only be negotiated if the subject matter is broadly understood. As we know well from a domestic perspective, you can only regulate what you know. If such an approach is taken to an extreme, we may not be in a position to regulate, or consider a treaty, for most environmental challenges. When the United National Framework Convention on Climate Change (UNFCCC) or the Convention on Biological Diversity (CBD) were negotiated and adopted, not everything about climate change or biodiversity was known. However, a system was put in place to build scientific knowledge on the subject matter to support continued action at the international level, so as to underpin the development of the treaty regime. The creation of the Intergovernmental Panel on Climate Change to, ‘provide policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options’and later on, the formation of the  Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services as ‘the intergovernmental body which assesses the state of biodiversity and of the ecosystem services it provides to society’, follows such an approach.

In the case of ocean plastics, the following questions still need to be fully addressed and do not have clear-cut answers. How much plastic is being produced every year? How much of it ends up in our oceans? Where does it come from? What is the impact of specific sectors and industries to the problem of global plastics? How much plastic can be recycled before it reaches our oceans and moreover, once recovered, to what extent can marine plastics can be recycled?

The need for clear and reliable data on the scale of the plastics problem has never been more urgent. For example, a recent study by the UN Conference on Trade and Development (UNCTAD) with the Graduate Institute, Geneva, found that ‘exports of primary, intermediate and final forms of plastics’ amounted to more than US$1 trillion in 2018. While this figure is startling in itself, it is ‘almost double previous estimates that did not capture the entire plastic life-cycle nor the breadth of plastics products traded internationally.’ The point being made here is that in respect of numerous aspects of the plastics pollution problem, so-called data graveyards exist. As noted in a 2020 report by the Pew Trust,

‘Consistent definitions and conventions for plastic waste data and metrics are lacking, and there is insufficient transparency regarding the plastic being placed on the global market (type, chemical additives, etc.), trade flows, waste production, consumption, and post-use patterns… The result is a very data-poor debate, often led by opinions and preconceptions instead of facts.

While it may be too ambitious to have all the answers to the questions we posed above before laying out the foundations of a global treaty, what is, however, needed is to build on these foundations a system to increase marine plastics science to help build our collective understanding of the problem.

Marine Plastics and the One Ocean Hub

The One Ocean Hub researchers work on a number of areas that are directly or indirectly related to the marine plastics challenge, including international water law, international trade law and the relevance of human rights and environmental justice to the marine plastics debate. Below we set out the relevance of some of the Hub’s work to oceans plastics, exploring how these areas might provide additional legal avenues to the marine plastics problem.

International Water Law

According to some studies, 70-80% of the plastics found in our oceans come from rivers. It was first thought that just ten rivers were responsible for the vast majority of the plastics flowing into the oceans from rivers, but new data appears to show that the number is likely to be closer to 1000 rivers. Furthermore, many of these rivers are transboundary with plastics flowing downstream from one country to another before ending in the sea. Whether the figures above are correct or not, it is self-evident that part of the solution to the marine plastics problem needs to be explored not only at sea, but also within rivers and their basins. If that is the case, then the question becomes whether part of the solution can also be found in the law that applies to transboundary rivers. Such law can be found in the United Nations Watercourses Convention (UNWC) and in the regional United Nations Economic Commission for Europe (UNECE) Water Convention. Despite the few countries that have ratified the UNWC or the limited geographical coverage of the UNECE Water Convention, both arguably have provisions that reflect customary international law that are worthy of being considered in a more complex normative picture to the marine plastics problem.

In an ideal scenario, no or less plastics would enter the river. And if plastic does reach the river, again in an ideal scenario, countries would attempt to remove such plastics before it reaches the sea. The question hence becomes whether international water law puts obligations upon countries that prevent plastics from entering a river and obligations that mandate countries to remove plastics from the rivers. Clearly, that is not the case. International water law is not that specific and was developed at a time when marine plastics was not considered a problem. However, international water law does lay on countries one key obligation, the obligation not to cause significant harm, and gives states a key right, the right to use the waters in an equitable and reasonable manner. International water law, all international law, needs to be interpreted under a current contemporary lens, which leads to the following (research) questions:

  • Does the obligation not to cause significant harm in international water law prevent upstream States from “dumping” plastics in the river if it leads to negative effects on downstream States and to the sea?
  • Does the equitable and reasonable utilisation principle entitle riparian States to undertake certain socio-economic activities within the river basin that causes plastics to be “dumped” into the river?

Here, the analysis of the relationship between the no harm rule and the equitable and reasonable utilisation principle in international water law becomes of crucial relevance. The UNWC, the UNECE Water Convention and international customary law applicable to transboundary waters includes several procedural obligations (to notify, to exchange information, to undertake an environmental impact assessment) that may also have practical implications on plastics ending up in the river and flowing downstream. All these questions will be posed and discussed in future work of the One Ocean Hub.

A specific example can be seen when a country has adhered to both the UNWC and the UNECE Water Convention and how this may affect the issue of marine plastics in that country. Ghana, a One Ocean Hub country, falls into this category and the One Ocean Hub looks forward to working with local policy makers and stakeholders to explore the normative maze dealing with ocean plastics that will need to also consider international water law.

International Trade Law

Trade is implicated in the problem of marine plastic pollution in a myriad of ways. First, trade can facilitate the move towards a more resource-efficient economy, promoting the creation of value chains in respect of recycling and more generally, enabling the transition to a circular economy. In this sense, trade and policies aimed at promoting the circular economy can and should be mutually supportive. The key question therefore is how to ensure that trade law and policy plays an enabling role in encouraging the transition to a circular economy.

Plastics pollution and plastics trade are increasingly being discussed within the World Trade Organisation (WTO), which last year saw the launch an Informal Dialogue on Plastics Pollution and Environmentally Sustainable Plastics Trade. This initiative is seen as an important element to growing the ‘sustainability agenda and the “blue economy” agenda at the WTO’ and as a demonstration of attempts by the membership of the WTO to address 21st century trade concerns. This initiative is very much complemented by the launch this year within the WTO of, ‘structured discussions on trade and environmental sustainability.’ A number of Members have highlighted plastics pollution and the circular economy as priority items for discussion within this context, and plastics trade features within the context of the (permanent) WTO Committee on Trade and Environment.

By bolstering capacity-building work in the area of international trade law and marine plastic pollution, the One Ocean Hub aims to contribute to the policy debate on how best to utilise law and policy to ensure trade law is supportive of the blue economy in general, and marine plastics in particular. With certain WTO Members calling for a work programme on plastics pollution and environmental sustainability to be launched at the next Ministerial Conference in late 2021, there is a critical need for such capacity-building.

Human Rights and Environmental Justice

As discussed in a previous Hub blog post, marine plastics constrain the ability of individuals to enjoy the highest attainable standard of health. Direct impacts of marine plastics on human health include direct human exposure to toxins through skin contact, inhalation, and direct ingestion, which could occur at various stages of the plastics lifecycle. Indirect impacts capture a wider range of interactions whereby various stages of the plastics lifecycle induce a change in something else (e.g. the atmosphere, non-human species, etc.) that in turn yields knock-on implications for ecosystems and the services they provide, human health and food safety. Viewed through a human rights lens, the harm to marine biodiversity from plastic pollution threatens the enjoyment of both the right to health and the right to adequate food. Continued action by states to allow harmful practices around the production, use and disposal of plastics may constitute a breach of the obligation of non-retrogression. In addition, states have an obligation to ensure non-discrimination, which may be triggered by the uneven health and food impacts of plastic pollution and the subsequent impacts on marine biodiversity described above, which will likely perpetuate existing inequalities. Finally, states must use “maximum available resources,” (ICESCR, Article 2(1)) including not only financial resources, but also human, technological, organisational, natural and information resources, in taking steps to realise the rights to health and food. 

One Ocean Hub researchers recently contributed to the UN Environment Programme’s (UNEP) new study on Environmental Justice Impacts of Plastic Pollution (here), offering views on the relevance of international developments on business responsibility to respect human rights, and opportunities to expand UNEP’s engagement with environmental justice scholarship in tackling ocean plastics in the future, including considerations of the impacts of single-use plastic bans on persons with disabilities. In addition, the Hub is collaborating with the UN Environment Programme (UNEP) to do develop e-learning materials on the various areas of international law (law of the sea, multilateral environmental agreements, human rights) that are relevant to support the implementation of SDG 14, including on marine litter and ocean plastics.


Marine plastics is a challenging topic that needs to be addressed urgently. As much plastic as possible needs to be taken out of our ocean and from any waterways that bring plastics into the sea. At the same time, if the root causes of marine plastics are not dealt with properly, this will just be a patch that will not provide a long-term solution. The production and consumption of marine plastics needs a holistic approach that may require a global treaty. However, a treaty approach may be premature due to the lack of solid data and because of some inherent challenges in public international law. Without removing a treaty from the policy options going forward, the One Ocean Hub highlights a plethora of other existing areas of international environmental law and international human rights obligations that deserve to be carefully scrutinised to determine their normative potential to provide legal avenues to the marine plastics problem. Not one of them alone with solve the problem, but together they can provide a first step towards stopping the flow of plastics into our ocean.