Microplastics hamper oceans’ ability to absorb CO2, study says

New Delhi: Microplastics could be impacting the oceans' ability to absorb carbon dioxide (CO2) which is critical for regulating Earth's temperature, according to a research.

'Biological carbon pumping' is a natural process by which an ocean transfers carbon from the atmosphere into the deep sea layers.

"Microplastics (MPs) interfere with this process by reducing phytoplankton photosynthesis and impairing zooplankton metabolism," authors including those from the University of Sharjah in the United Arab Emirates said.

Author Ihsanullah Obaidullah, associate professor of integrated water processing technologies, said, "Oceans are Earth's largest carbon sink. Microplastics are undermining this natural shield against climate change. Tackling plastic pollution is now part of the fight against global warming."

The research, published in the Journal of Hazardous Materials: Plastics, reviewed 89 studies published from 2010 to 2025. Peer-reviewed articles and reports from international organisations were among the content analysed to understand effects of microplastics on ocean health and climate change.

"(The) review highlights the close relationship between MP (microplastic) pollution and climate change, suggesting that MPs may significantly contribute to climate change and potentially further affect ocean health in the form of ocean warming and ocean acidification," the authors wrote.

Microplastics are fragments of plastics sized under five millimetres. Studies have provided evidence of presence of microplastics across varied environments from deep ocean waters to human bodies.

Over 8.3 billion tonnes of plastic have been produced globally to date, with 80 per cent ending up in landfills or the environment -- only nine per cent of the massive volume is recycled, the researchers said.

Toxins in microplastics are ingested by living creatures, including humans, triggering a range of diseases, disrupting ecosystems, harming aquatic life, and reducing soil fertility, the researchers said.

The team called for an integrated approach as microplastic pollution and climate change cannot be addressed in isolation, they said.

Coordinated efforts are needed to develop governance frameworks that tackle both microplastic pollution and climate change, particularly their links to ocean acidification and warming, they added.

Reducing single-use plastics and improving waste management are among the recommendations the researchers suggested to preserve oceans and their ability to absorb carbon dioxide.