Scientists warn that microplastics are hindering the ocean's ability to absorb greenhouse gases, thereby undermining the Earth's role in regulating the climate.
The ocean provides approximately 50% of the oxygen for humans, absorbs 30% of CO2 emissions, and retains up to 90% of excess heat from greenhouse gases. Therefore, the ocean is considered the planet's largest carbon sink, playing a crucial role in slowing down global warming.
However, a new study published in the Journal of Hazardous Materials has highlighted the worrying impacts of microplastics on the ocean's climate-regulating function. The research team from the University of Sharjah (UAE) analyzed 89 scientific papers to synthesize existing evidence relating to microplastics and ocean health.
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The results show that microplastics can disrupt marine life and also release greenhouse gases during their decomposition. Notably, microplastics weaken the "biological carbon pump," a natural mechanism that transports carbon from the atmosphere to deep water layers.
The reason is that microplastics reduce the photosynthetic capacity of phytoplankton, microscopic organisms that produce oxygen and absorb CO2. In addition, they affect the metabolism of zooplankton, a crucial link in the marine food chain.
According to Ihnsanullah Obaidullah, Associate Professor of Integrated Water Treatment Technology, these long-term impacts could lead to ocean warming, acidification, and biodiversity loss, thereby threatening food security and coastal communities worldwide.
If the ocean's ability to absorb excess CO2 and heat declines, it risks shifting from its role as a carbon sink to a source of greenhouse gas emissions. Similar phenomena have been observed in many large tropical rainforests around the world, including South America, Southeast Asia, and Africa.
The study was published amid predictions by scientists that 2026 could be the fourth consecutive year that global temperatures exceed a 1.4°C increase above pre-industrial levels, approaching the 1.5°C threshold set by the Paris Agreement.
A 2025 report by the United Nations indicates that global plastic production currently exceeds 400 million tons per year, with more than half being single-use products. Without control measures, this figure could triple by 2060.
Although plastics still play an essential role in many fields such as aviation, electronics, and consumer goods, scientists warn that overuse is creating serious risks to the environment and food security.
The study emphasizes the need for a holistic approach, as microplastic pollution and climate change are closely linked and cannot be addressed in isolation. According to the research team, controlling microplastic production could contribute to mitigating the impacts of climate change.
In the future, the research team will continue to quantify the impact of microplastics on the climate in more detail, while also developing integrated solutions to effectively address this issue.