The Great Pacific Garbage Patch is a plastic trash nightmare. It could also be part of a much bigger, hidden problem

By Laura Paddison, CNN

(CNN) — Out in the Pacific Ocean, between Hawaii and California, is the Great Pacific Garbage Patch, a swirl of plastic trash more than twice the size of Texas. As pieces of plastic tumble against each other, they break down into particles tiny enough to be borne aloft on the wind. Once in the air, they have a climate impact that could affect us all, according to new research.

The Great Pacific Garbage Patch is a significant source of airborne microplastics and nanoplastics, but there are many other places where tiny plastic particles can be whipped up into the skies, including from landfills, roadside litter and car tires.

A team of scientists from China and the US have studied the makeup and behavior of these plastics, and found they are contributing to global heating, according to the study published Monday in the journal Nature.

Most microplastics research has focused on their health and environmental dangers, but this report “reveals a long overlooked link between plastic pollution and climate change,” said Hongbo Fu, a study author and an atmospheric scientist at Fudan University in Shanghai.

The scientists zoomed in on microplastics, usually the size of a pencil eraser or smaller, and nanoplastics, which are the tiniest particles, many times smaller than the width of a human hair. They analyzed color, size and chemistry to understand more about how they interact with sunlight.

They wanted to know whether particles scattered sunlight back into space — meaning they would have a cooling influence on the planet — or whether they absorbed sunlight, which would have a warming impact.

Previous research has suggested microplastics’ contribution to global warming was negligible, but analyses have often assumed particles were clear, the report scientists said. What they found was a rainbow of colors.

Colored plastics, especially red, yellow, blue and black, absorbed around 75 times more light than pristine, non-pigmented plastics, the study found. They “act like black T-shirt; they soak up heat,” Fu said.

Size is also a factor, although to a lesser extent. The smaller the particle, the more sunlight it was able to absorb, the report found. “Nanoplastics are tiny but powerful. They stay in the air longer and, for the same mass, they absorb much more sunlight than microplastics,” Fu said.

The scientists also found the plastics’ warming impact could change over time. They artificially aged them in the lab using ultraviolet lamps and found that white particles tended to yellow, meaning they absorbed more sunlight. Red particles, on the other hand, sometimes bleached, meaning they scattered more light.

Most particles are darker, either because they start that way or darken as they float around the atmosphere and age, said Drew Shindell, a study author and a professor of Earth science at Duke University. The big advance of the paper, is that “we can pin down that the net effect is that almost all of these particles are warming more than cooling,” he said.

The warming effect may be small at a global level but it’s not insignificant, the scientists said. Microplastics and nanoplastics produce roughly 16% the warming impact of black carbon, or soot, a powerful airborne pollutant.

In ocean areas where plastic gets caught in spinning currents, such as the Great Pacific Garbage Patch, the warming impact is particularly pronounced and may exceed black carbon, the study found. It’s “bits of plastic hitting other bits of plastic that causes the extra-large flux of material out into the atmosphere,” Shindell said.

Experts told CNN the study results are interesting and build on previous findings, but do have significant limitations.

“What’s new here is the numbers,” said Zamin Kanji, group leader of the Atmospheric Physics Lab at ETH Zürich in Switzerland, who was not involved in the research. The study systematically quantifies the size and pigment of various plastics and their impact on sunlight, he told CNN.

The finding that microplastics have a warming impact isn’t new however, he said, pointing to a 2021 study, which made the same finding. “The number in the latest study is higher,” Kanji said, but the previous paper projected the impact was likely to rise as more data became available, plastic production rose and plastic already in the environment broke down.

We won’t get a full picture of the climate impact until we have better data on how much plastic is in the atmosphere, Kanji said. “This will take a long time to robustly quantify,” he said.

Natalie Mahowald, chair of the Department of Earth and Atmospheric Sciences at Cornell University, who was also not involved in the research, said the study shows current levels of microplastics have a very small climate impact, although that could change if levels grow considerably.

“In my opinion, the most important impacts of microplastics are likely to be on health, but we still don’t know very much about them,” she told CNN.

The study authors acknowledged it’s exceptionally hard to measure exactly how many plastic particles are in the air, but said they say they are confident that even with these uncertainties, the net impact is warming. “Our work suggests that climate models need to be updated,” Fu said.

The-CNN-Wire
™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.