This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Halting new marine plastic inputs by 2050 is the core objective of the Osaka Blue Ocean Vision, which was shared and endorsed alongside the G20 Implementation Framework for Actions on Marine Plastic Litter. However, stopping new plastic inputs will not remove existing marine debris, which can gradually fragment into microplastics that are difficult and costly to remove.
Source reduction must therefore be accompanied by cleanup of legacy plastic debris. To investigate this, professor Takuro Uehara of the College of Policy Science at Ritsumeikan University in Japan collaborated with Dr. Mateo Cordier of Université de Versailles-Saint-Quentin-en-Yvelines—Université Paris-Saclay in France and Laurent Lebreton of The Ocean Cleanup in the Netherlands.
They developed a system dynamics model examining the physical and economic effort required to address initially buoyant marine plastic debris by 2050. Their findings were published in the journal Communications Earth & Environment. The model simulates the transport, degradation and cleanup of macroplastics and their breakdown into microplastics across shoreline, coastal and offshore zones.
"The framework is designed to look at marine plastic pollution as a dynamic problem rather than a one-time cleanup challenge," Uehara said. "By linking plastic inputs, the movement and breakdown of debris, cleanup timing and location, and the associated costs, it allows us to explore which combinations of prevention and cleanup could be both environmentally effective and economically realistic. This provides a basis for more informed decisions about where and when cleanup efforts should be prioritized." The model followed the transport and degradation of macroplastics and their breakdown into microplastics across shorelines, coastal waters and offshore areas.
The researchers tested seven scenarios combining different pathways for reducing plastic inputs with different approaches to cleanup. In scenarios aimed at stopping plastic at its source, inputs were progressively reduced from 2026 until reaching zero by 2050. The model then compared cleanup strategies to assess how the timing and intensity of these measures could influence the amount of plastic remaining in the ocean.
The modeling showed that halting plastic inputs by 2050 could reduce the cumulative amount of plastic entering the ocean between 1950 and 2050 by 51.4% compared with the business-as-usual (BAU) scenario. However, stopping new inputs alone did not resolve the legacy of plastic already in the ocean. Without cleanup, microplastics were projected to make up 58.4% of accumulated plastic by 2050.
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