The Impact of Plastic Pollution on the World’s Oceans: Trends and Conclusions
Today’s global abundance of floating ocean plastics is estimated at approximately 82–358 trillion particles weighing 1.1–4.9 million tonnes.
Plastic pollution has become one of the most pressing environmental issues of our time, and there is a growing concern about its impact on marine ecosystems. A recent study has shed light on the global distribution and abundance of plastics in the open sea, and the trends that have emerged over the past few decades. The study shows that there has been a significant increase in the concentration of plastics in the oceans since the turn of the century, with a dramatic increase from 2005 onwards.
The study also identifies a number of factors that may have contributed to these trends, including policy interventions, plastic production, fragmentation of existing floating plastic, and waste management and trade. There is evidence to suggest that policy measures implemented during and before 2006 may have contributed to the stagnation of plastic pollution levels during this period. For example, the MARPOL agreement, which was signed by 154 countries in 1988, established legally-binding agreements to end the discharge of plastics from naval, fishing, and shipping fleets. Similarly, the Plastic Industry Trade Association launched “Operation Clean Sweep” in 1991 with a goal of zero loss of plastic pellets, powders, and flakes from factories.
However, the rapid increase in plastic pollution levels from 2005 onwards may reflect the exponential growth of plastic production, as well as changes in terrestrial waste generation and management. Older macroplastics that are adrift or stranded on shorelines or in rivers continue to degrade and fragment, contributing to the increase in the abundance of microplastics.
The authors in the study also highlight the need for more data from the South Atlantic, South Pacific, and Indian oceans, which remain data-poor regions. They suggest that greater attention needs to be given to the southern hemisphere, and that sampling needs to occur at more even intervals so that models can provide outputs with higher resolution that can better identify spatial and temporal trends.
The study underscores the urgent need for effective global governance to address the plastic pollution crisis. In early 2022, all Member States adopted a resolution to end plastic pollution at the United Nations Environmental Assembly 5.2. in Nairobi, committing to establish a legally binding global agreement that addresses the full life-cycle of plastic, including its production, design, and disposal, by 2024. The final outcome of this agreement will be a treaty, but its strength will depend on commitments by the member states and on whether measures are focused on the full life cycle of plastics, from extraction and manufacturing to its end of life.
The study concludes that establishing standardized monitoring frameworks to track global trends and creating binding and enforceable international agreements to prevent the emissions of plastic pollution are the best long-term global solutions. Environmental recovery of plastic has limited merit, so solution strategies must address those systems that restrict emissions of plastic pollution in the first place.
Overall, the study provides valuable insights into the trends and factors that have contributed to the global distribution and abundance of plastics in the open sea. It highlights the urgent need for effective global governance to address the plastic pollution crisis, and emphasizes the importance of establishing standardized monitoring frameworks and creating binding and enforceable international agreements to prevent the emissions of plastic pollution.