It’s not an exaggeration to say that microplastics are everywhere. The micrometer-size plastic particles slough off of bottles, clothes, paint, and every other plastic material in the world, polluting the planet from mountaintops to ocean depths. Recently, researchers have shown that microplastics, and even smaller nanoplastics, are also lofted into the atmosphere.
Now an international team of researchers has quantified the potential climate impact of atmospheric micro- and nanoplastics (Nat. Clim. Change 2026, DOI: 10.1038/s41558-026-02620-1).
Scientists haven’t known if microplastics act as warming or cooling agents in the atmosphere, says Drew Shindell, a professor of earth science at Duke University, during a press briefing about the new research. The amount of radiative forcing coming from airborne plastic particles—basically, their ability to affect climate—was a mystery. Researchers knew the answer would be found in the particles’ optical properties: If they scatter sunlight back into space, they may be cooling the atmosphere. But if they absorb radiation, they could be warming it.
“Our lab is uniquely equipped to perform such detailed optical measurements,” Hongbo Fu, an aerosol researcher at Fudan University, writes in an email to C&EN.
Fu’s team used electron energy-loss spectroscopy (EELS) to precisely measure the optical properties of individual micro- and nanoplastics. The analytical technique can provide structural and chemical information for a sample, down to the atomic level, when it’s performed with a transmission electron microscope.
“The process of calculating optical properties from EELS spectra is a complex challenge, but fortunately, we have successfully solved this problem,” Fu writes.
The scientists found that polymer type and particle size both affect a microplastic’s optical properties. But color plays the largest role in radiative forcing. “Black, yellow, blue, and red microplastic particles absorbed light much more strongly than white particles,” Fu writes.
Armed with this new information, the researchers used global climate models to calculate the effects of microplastics. “We can pin down that the net effect is that almost all of these particles are warming more than cooling,” says Shindell.
In fact, the researchers’ climate simulations showed that, on average, the warming caused by microplastics was about 16% of that from atmospheric black carbon—essentially, soot. Black carbon is one of the most significant contributors to global warming, so it appears that the climate impact of microplastics is “not an enormously large one but not a trivial one either,” Shindell says.
“As plastic production continues to rise worldwide, understanding [microplastics’] role in the atmosphere is becoming increasingly urgent,” writes University of Insubria researcher Gilberto Binda, in the accompanying News and Views article. Unfortunately, scientists are still trying to understand exactly how much plastic is floating around the atmosphere at any given time. Still, “these findings suggest that airborne microplastics and nanoplastics are not just an environmental contamination issue, but potentially an emerging climate factor,” Binda writes.
2026 American Chemical Society
