Microplastics Are Swirling Around in the Atmosphere, Where They Might Be Contributing to Climate Change

Airborne plastic particles, particularly colorful ones, absorb more sunlight than they reflect, which can heat the surrounding air, according to a new study

Sara Hashemi | Daily Correspondent

May 12, 2026 12:49 p.m.

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No corner of the Earth seems to be safe from tiny particles of plastic. They’ve been found in our lakes, soil and food, and they even float in the air, traveling across the globe. Now, new research suggests that microplastics swirling in the atmosphere are contributing to the warming of our world.

Colorful bits absorb more sunlight than they reflect, which can heat the surrounding air, researchers report May 4 in the journal Nature Climate Change. The findings suggest that airborne plastic particles might play a larger role in climate change than previously thought, and that they should be more widely included in climate assessments.

“This article shows a very worrying truth about the dangers of micro- and nanoplastics,” says Steve Allen, a microplastics researcher at the environmental advocacy organization Healthy Earth, to Scientific American’s Jackie Flynn Mogensen. Allen was not involved in the study.

Plastic particles less than five millimeters long, or smaller than a pencil-top eraser, are considered microplastics. Even tinier pieces, less than one millimeter long, or narrower than a pencil tip’s width, are called nanoplastics. They mostly come from the breakdown of plastics in textiles, tires and other consumer products.

Although researchers have been looking into their effects on human health and the environment, they weren’t sure whether atmospheric plastics could influence climate change.

So the researchers behind the new work examined how various particle characteristics—including size, color, chemical composition and aging—might influence the plastic bits’ interactions with sunlight. In a lab, they measured what happened when micro- and nanoplastics were exposed to different wavelengths of light, revealing that color plays a major role.

“Black, yellow, blue and red [particles] absorb sunlight much more strongly than the white particles,” said study co-author Yu Liu, an environmental scientist at Fudan University in China, during a press conference, as reported by the Washington Post’s Brady Dennis.

In fact, at a wavelength of light that looks green to humans, colorful particles absorbed light at levels almost 75 times higher than nonpigmented pieces, the team found. After color, size also seemed to be important. Analyses revealed that tinier plastic bits absorbed and scattered light more strongly at shorter wavelengths, then dropped off at longer wavelengths, while bigger particles showed a broader, more gradual pattern of interaction across wavelengths.

Combining this information with computer simulations of worldwide airborne microplastics revealed how big a role the particles might play in climate change. Their impact on global warming may amount to roughly one-sixth that of black carbon, or soot, a major component of air pollution, primarily produced by burning fossil fuels, the team found. That’s a “substantial fraction,” the study authors write, given that plastic particles are a pollutant class that hasn’t been widely included in climate assessments.

“These findings suggest that airborne microplastics and nanoplastics are not just an environmental contamination issue, but potentially an emerging climate factor,” writes Gilberto Binda, a microplastics researcher at the University of Insubria in Italy who was not involved in the study, in an accompanying article in Nature Climate Change. However, researchers lack comprehensive data on plastic concentrations in the atmosphere, particle sizes, chemical makeup and other factors that might contribute to sunlight interactions, he notes, so “major uncertainties remain.”

Additionally, while the work was interesting, it wasn’t conducted in a real-world setting, says Ria Devereux, a microplastics researcher at the University of East London, who also wasn’t involved in the study. “The laboratory conditions used were simpler than in the real world as plastics break down in more complex interconnected ways not just from [ultraviolet light], but from humidity, chemicals, wave action to name a few,” she says in a commentary compiled by the Science Media Centre.

Even though microplastics’ effects on the climate aren’t fully understood, experts say that the pollutant’s threats to human health and impact on the environment already show we need to curb it.

“Eventually, climate effects may be another reason for this,” Andreas Stohl, a climate scientist at the University of Vienna who did not participate in the research, tells the Washington Post. “But I think we need another ten years of studies before we can draw firm enough conclusions.”

Sara Hashemi | Read More

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.