Plastic in the oceans: why is a solution still far away?

According to scientific estimates, millions of tonnes of plastic end up in the world's seas every year, although the exact figures differ considerably depending on the methodology. Most of the waste does not end up directly in the sea, but gets there via rivers, especially in parts of Asia, where the infrastructure for collection and processing cannot keep pace with the growth in consumption. The role of fishing must not be overlooked either, as lost or discarded nets continue to catch fish, turtles and dolphins for years.

Ocean currents, which form huge circular systems in the northern Pacific, have for decades been concentrating floating waste in a few areas. The best known of them, the so-called Great Pacific Garbage Patch between California and Hawaii, according to estimates is about three times larger than France. However, the image of a floating island of rubbish on which one could walk is misleading: the waste has mostly broken down into countless tiny fragments that drift below the surface and can hardly be seen from the deck of a ship. For marine animals the consequences are often fatal: turtles mistake plastic bags for jellyfish, and seabirds feed their young with pieces of plastic, which can lead to death by starvation on a full stomach.

Under the influence of ultraviolet radiation and the mechanical action of the waves, plastic does not decompose, but merely breaks down into ever smaller particles. Fragments smaller than five millimetres are referred to in the specialist literature as microplastics. They have now been detected almost everywhere, from the summit of Mount Everest to the Mariana Trench, which shows how deeply plastic has penetrated global ecosystems. Microscopic particles have also been found in table salt, in drinking water and even in human blood and in the placenta, although the measurement methods are still the subject of scientific debate. Whether and to what extent microplastics harm human health, for now it is not possible to say with certainty; however, many researchers believe that it would be reckless to wait for conclusive evidence before taking action.

In 2019 the European Union responded with a directive on single-use plastics, which is aimed at the products that are most frequently found on European beaches. Since 2021 straws, plastic cutlery and cotton buds have been banned in the member states, provided that easily available alternatives exist. Critics nevertheless point out that such bans are symbolically important, but cover only a small part of total plastic waste, and that without reducing production the problem will not be solved.

Precisely for this reason, in 2022 the member states of the United Nations agreed to draw up a legally binding global treaty that would cover the entire life cycle of plastics, from production to disposal. The negotiations, which were supposed to be concluded by the end of 2024, have so far remained without result, because the interests of the participants can hardly be reconciled. Numerous states, including the members of the European Union, are calling for binding limits on the production of primary plastic, because they believe that recycling alone would not be enough. On the other hand, oil-producing countries such as Saudi Arabia and Russia reject any restrictions on production and want the treaty to be limited above all to better waste management. If no compromise is found, there is a danger that in the end a treaty without real force will be adopted, which would serve more as a symbol than as an effective instrument.

Only one thing seems certain: as long as global plastic production continues to grow, not even the best recycling systems will be able to stop the flow of waste into the oceans. Therefore the solution probably won't come from technology alone, but will require profound changes in the way in which we produce, package and consume.