Airborne microplastics could be making climate change worse

Microplastic particles flowing through Earth’s atmosphere may be quietly driving up global temperatures, a new study suggests.
Microplastics and nanoplastics—tiny bits of broken-down plastic pollution—litter the planet’s rivers, oceans, land and air. But until now, researchers weren’t sure what effect all those plastic particles were having on an already warming climate.
A new study led by researchers at Fudan University in China suggests that the particles may significantly affect warming—for comparison, microplastics’ warming effect equates to about 16 percent of that of black carbon, or soot.
“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, who was not involved with the study.
If you’ve ever walked barefoot on asphalt, you know black material absorbs heat. White paint on asphalt, however, reflects it. The same thing happens with airborne microplastics—darker colors warm the atmosphere, while lighter colors help cool it. By analyzing the optical properties of various microplastics in the lab and simulating their effect on a global scale, the new study’s authors estimated that microplastics’ warming abilities outweigh their potential cooling effects—something current climate models don’t account for. The results were published on Monday in Nature Climate Change.
The findings reveal “a long-overlooked link” between plastics and climate change, said study co-author Hongbo Fu, a researcher at Fudan University in China, at a press conference. Plastics are not just an environmental pollutant. “They can also act as a heating agent in the atmosphere,” he said.
“We still have a lot to learn about exactly how many of these [microplastics] are in the atmosphere and how they’re distributed, both horizontally and vertically,” said Drew Shindell, the study’s senior author and a professor of Earth science at Duke University, at the same press conference. “This is not the final word.”
More broadly, Allen says the results underscore the need to reduce our reliance on plastics—which are often made from the by-products of fossil fuel production.
(Scientific American)