By Abbas Nazil
A new scientific study has warned that microplastics accumulating in the world’s oceans are weakening their ability to absorb carbon dioxide, one of Earth’s most-critical natural defenses against global warming.
Researchers indicate that tiny plastic particles are disrupting key marine biological processes, which allow oceans to store carbon and regulate the planet’s temperature.
Currently, oceans absorb roughly a quarter of human-caused carbon dioxide emissions annually, making them the planet’s largest natural carbon sink.
“Issues like microplastic pollution are undermining this natural shield against climate change,” said Ihsanullah Obaidullah of the University of Sharjah, one of the study’s authors.
The study, published in the Journal of Hazardous Materials, is based on a comprehensive review of existing research rather than new laboratory experiments.
The research finds that microplastics interfere with the biological carbon pump, a process driven by phytoplankton and zooplankton that transfers carbon from surface waters into the deep ocean.
Microplastics were found to reduce photosynthesis in phytoplankton, impair metabolism in zooplankton, and weaken the carbon sequestration mechanism overall, diminishing the ocean’s ability to store greenhouse gases.
The study also emphasizes the role of microbes that colonize plastic particles, known as the “plastisphere,” which can disrupt carbon and nitrogen cycles and even contribute to greenhouse gas emissions.
“Microplastics disturb marine ecosystems, weaken the biological carbon pump, and release greenhouse gases as they degrade,” Obaidullah said, highlighting potential long-term consequences including ocean warming, acidification, biodiversity loss, and threats to food security and coastal communities.
While evidence of ecological harm from microplastics is mounting, the full extent of their impact on global climate remains poorly understood.
Global plastic production currently stands at 400 to 430 million tons annually, with less than 10 percent recycled, and researchers warn that production could triple by 2060 without stronger controls.
The study calls on governments and international organizations to treat plastic pollution and climate change as interconnected challenges, advocating accelerated action to reduce plastic use, improve waste management, and expand research on microplastics’ climate effects.
“Our next step is to quantify the climate impact of microplastics and develop integrated solutions,” Obaidullah said, stressing that the issue represents a broader global sustainability challenge rather than an isolated environmental problem.
The research underscores the urgent need for a coordinated approach, linking pollution management with climate mitigation strategies to protect the oceans’ carbon-absorbing capacity.
Experts warn that without immediate and coordinated intervention, microplastic pollution could significantly compromise the oceans’ ability to act as a climate buffer, exacerbating global warming and its associated environmental and social impacts.
The study adds to growing evidence that human activities are increasingly threatening marine ecosystems, highlighting the importance of reducing plastic pollution to safeguard natural climate regulation processes.
Long-term solutions will require policy, research, and public engagement to address both the proliferation of plastics and their far-reaching consequences on the planet’s climate system.
