What are the solutions for combatting ocean pollution?​​​​​​​

The decision by the United Nations to dedicate the decade 2021-2030 to protecting the oceans reflects an unavoidable reality: that ocean and maritime pollution is a top priority challenge from an environmental, social and economic point of view. After the One Ocean Summit in Brest last February and amid ongoing discussions about a binding international agreement on plastic pollution, the time for action is now. We look at the initiatives currently underway by governments, businesses and ordinary people.

Published on 28 October 2022

Tackling ocean pollution means dealing first of all with the world’s most visible and well-known pollutant: plastic. The third most manufactured material after cement and steel, its durability and low cost continue to ensure its commercial success. However, a year after entering circulation, more than 80% of plastics become waste, a significant proportion of which end up in the oceans¹.  Based on a summary of more than 2,000 scientific studies on the subject, the WWF has highlighted the omnipresence of plastic in the oceans “from the smallest plankton to the largest whale².” Plastic pollution is not just about pictures of turtles that choked to death after swallowing a plastic bag: the fragmentation of plastics due to UV rays and the impact of waves makes them all the more harmful. Some 24.4 trillion³ particles of less than 5mm in size are estimated to be floating in the world’s seas. Even in a very hypothetical case of suddenly preventing any new plastic from ending up in the ocean, the quantity of microplastics already there would still double by 2050⁴. At the current rate, according to the WWF, the amount of debris could even quadruple by 2050⁵ …

However, plastic is far from the only danger. Field runoff, rivers, rain and aerial spraying inevitably carry chemicals, fertilisers, pesticides, heavy metals, hydrocarbons and other medicinal residues into the world’s oceans. A 2021 report by the International Pollutants Elimination Network (IPEN) is particularly alarming, pointing to a series of consequences in different areas⁶, such as fertilisers creating over-fertilisation that leads to algae blooms and chemical residues that reduce the resistance of bears, sea lions and seals to infection.

The situation clearly demands a massive response and a framework for action by international authorities. Until the 1970s, it was believed that the sheer scale of the world’s oceans meant they could be used as dumping grounds for dangerous substances. In 1972, the signing of the London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter was a first step forward. In 1996, a new agreement banned the dumping of radioactive and industrial waste and the incineration of toxic waste at sea. Although the global community is gradually dealing with this issue through various international regimes and instruments, the task remains immense. As with the problem of overfishing, the challenge lies both in the signing of truly ambitious international agreements and then in their effective application, with the latter depending on the quality of the tracking tools and control measures being used.

That said, plastics remain the obvious priority. A key part of the solution will be to simply reduce production, starting with plastic packaging (40% of global production) and single-use products. The European Union’s adoption in 2019 of the SUP (Single-Use Plastics) Directive, one of the most ambitious pieces of legislation in the world on the subject, represents a remarkable step forward. In addition to bringing in measures to reduce the use of single-use plastic products across the EU (cutlery, plates, cotton buds, coffee stirrers, etc.), the directive also introduced a ban from July 2021 on single-use plastic products for which reusable alternatives already exist.

Another challenge is the reuse and recycling of collected plastics. This is a huge challenge: only 9% of the 353 million tonnes of plastic waste has been recycled⁷. However, the situation is not all doom and gloom: a 2020 study by the journal Science⁸ shows that a fully effective use of all the solutions for reducing plastic use, collection and recycling could lead to an 80% reduction in waste by 2040. One of the keys to achieving this will undoubtedly be the growth and consolidation of a global plastics recycling industry. Eco-design, waste collection and sorting, the inclusion of recycled plastic in new products, reuse, recycling, recovery… these activities all need to be embraced by the world’s leading companies, with the support of government authorities and ordinary citizens who are aware of the issue.

Another priority area is to tackle the main contributors to global GHG emissions: the transport and energy sectors. As the latest report from the Intergovernmental Panel on Climate Change has highlighted⁹, recent years have seen the development of innovative, low-carbon technologies that can make a significant contribution to reducing emissions. While the panel stresses the complexity of decarbonising transport, the rise of alternative fuels (such as hydrogen and low-emission biofuels) in shipping can make a real impact – especially if coupled with a significant reduction in demand¹⁰. At the same time, transport emissions can also be reduced by simply lowering speeds.

The IPCC also stresses the need for further research and the monitoring of any negative side effects. Artificial intelligence and robotics will certainly play important roles in this. A remote-controlled robot device that collects waste in lakes, canals and marinas (Ecocoas); a laboratory ship powered by converting plastic waste into fuel (Plastic Odyssey); a floating facility that collects, sorts and recycles plastic waste (8th continent); a ship and barrier system for collecting plastic that is later transformed into consumer products onshore (Ocean Cleanup)… these are the kinds of innovations being created by start-ups, associations and NGOs to tackle the daunting task of cleaning up the seas¹¹.

Finally, let’s not forget that although it represents a major challenge, the oceans are also part of the solution. As a major carbon sink and a source of energy, the world’s seas are a valuable asset. The potential of offshore wind energy can be summed up in one figure: the International Energy Agency (IEA) estimates the potential of offshore wind energy at 420,000 TWh of electricity a year¹² – that’s 11 times the expected global demand for electricity in 2040. Another avenue is to accelerate carbon absorption and storage by using infrastructure that harnesses energy from “tides, waves, ocean thermal energy conversion (OTEC), currents and salinity gradients.” Meanwhile, the restoration of coastal wetlands (notably through rewetting and revegetation) and better management of water-based carbon offer many benefits in terms of biodiversity. To main this momentum, the financial community is set to have a key role to play. For as the IPCC makes clear, ” the demand of establishing new finance and business models to attract both public and private finance to nature-based solutions is increasing in a wide range of topics¹³.”