A study has found that airborne microplastics may affect global warming. Until now, plastic pollution has mainly been treated as an issue for oceans, soil, and ecosystems, but plastic particles in the atmosphere can absorb sunlight and warm the air.
An international research team including Fudan University in Shanghai, China, and Duke University in the United States published on the 5th in the journal Nature Climate Change the results of an analysis of the light-absorption properties of colored microplastics and nanoplastics.
Microplastics and nanoplastics are particles formed when large plastic waste breaks down into small pieces due to sunlight, waves, and friction. Microplastics are very small plastic fragments with diameters up to 500 μm (micrometers, one-millionth of a meter), and nanoplastics include particles much smaller, down to around 1 nm (nanometers, one-billionth of a meter). They are so small that they are hard to see, but they can ride air currents and travel not only across cities but also to remote areas.
The researchers used high-resolution electron spectroscopy to analyze how plastic particles absorb light and combined the results with atmospheric transport simulations. They found that black or multicolored plastic particles absorb sunlight much more strongly than white particles.
Assuming realistic concentrations of plastic particles in the global atmosphere, the radiative forcing of nanoplastics was estimated at 0.033 W per square meter, and microplastics at 0.006 W per square meter. Radiative forcing indicates how much the balance is disturbed between the energy Earth receives from the sun and the energy it sends back into space. The larger the value, the greater the effect of warming the atmosphere.
In this study, the warming effect of plastic particles corresponded to about 16.2% of that of black carbon (soot), a representative warming substance. In particular, over seas with high plastic concentrations, such as the North Pacific garbage patch, the warming effect of plastics could be up to 4.7 times higher than that of black carbon.
However, the researchers said, "The actual atmospheric environment is far more complex than the laboratory, and observations of where and how much micro- and nanoplastics exist in the global atmosphere are still lacking," and added, "Further research is needed to fully identify how micro- and nanoplastics contribute to global warming and to represent them more accurately in climate models."
Meanwhile, Koo Jae-ho, a professor in the Department of Atmospheric Sciences at Yonsei University who did not participate in this study, said, "In recent years in East Asia, fine dust has been decreasing as air quality improves. This is environmentally positive, but climatically it can weaken the effect of scattering sunlight and thereby amplify regional temperature increases," and added, "If, in such a situation, microplastics also act as a factor that warms the atmosphere, the warming burden could grow."
References
Nature Climate Change (2026), DOI: https://doi.org/10.1038/s41558-026-02620-1