A growing body of research suggests that the environmental impact of plastic pollution may go far beyond marine litter and wildlife harm. A new report by the Plastics & Climate Project warns that microplastics—tiny plastic fragments now found across the planet—may be undermining Earth’s natural ability to absorb and store carbon, potentially accelerating global warming in ways not yet fully accounted for in climate models.

Currently, plastic production is responsible for about 5% of global greenhouse gas emissions. That figure alone makes plastics a notable contributor to climate change. However, the report highlights that microplastics may pose an even broader threat by disrupting key biological and chemical processes in the oceans and soils—processes that are essential for the long-term storage of carbon.

“Our understanding of plastic’s role in the climate crisis has been too narrow,” the report states. “We must consider not just emissions from production and disposal, but also the broader ecological consequences that affect carbon cycling and storage.”

One major concern outlined in the report is the disruption of oceanic carbon sequestration. In marine ecosystems, a significant portion of atmospheric carbon is captured by phytoplankton and transported to the deep ocean via a process known as “marine snow”—organic material that sinks to the ocean floor. Microplastics can interfere with this process by binding to marine particles, making them more buoyant and less likely to sink. Additionally, microplastics have been shown to inhibit plankton growth and alter their feeding behavior, reducing the efficiency of carbon capture in the upper ocean.

The impact on terrestrial carbon storage may be equally significant. Microplastics in soil can interfere with microbial communities that help regulate carbon cycling. The report cites studies showing that plastic particles can reduce microbial diversity and activity, limiting the ability of soil to store organic carbon. This disruption could weaken one of the planet’s most important carbon sinks.

Moreover, emerging evidence suggests that plastic pollution may also affect the Earth’s radiative balance. As microplastics accumulate on snow and ice surfaces, they may alter reflectivity—or albedo—causing more solar radiation to be absorbed rather than reflected. This can accelerate melting in polar and alpine regions, further contributing to global warming. In addition, as plastics degrade in sunlight, they may release methane and other potent greenhouse gases, compounding their climate impact.

“These indirect effects are not just speculative,” said Dr. Elena Martínez, a climate scientist unaffiliated with the report. “We’re beginning to see how plastic pollution might influence everything from microbial soil health to ocean carbon drawdown. The climate system is interconnected, and small disruptions can have cascading effects.”

Despite the growing evidence, most global climate models and carbon accounting frameworks do not currently factor in the role of microplastics in altering carbon cycles. The Plastics & Climate Project is calling for urgent research into these emerging pathways to better understand plastic’s full climate footprint.

The report’s authors also warn that the continued growth in global plastic production—expected to double by 2050—could exacerbate these issues unless significant changes are made. They advocate for stronger regulations on plastic use, improved waste management systems, and investment in biodegradable alternatives.

“As we uncover more about how plastics interact with natural systems, it becomes clear that their environmental cost is much higher than we previously thought,” the report concludes. “To effectively address climate change, we must also address the hidden climate impacts of plastic pollution.”

The findings underscore the urgent need for interdisciplinary research and integrated environmental policy. With microplastics now detected in remote locations from Arctic ice to mountain peaks, understanding their impact on planetary systems is becoming an increasingly critical piece of the climate puzzle.