Microplastics are all around us—in our food, our water, and even our air. Now scientists have found that they have made it up into the clouds and could be affecting cloud formation and climates around the world.
Microplastics refer to any plastics that are smaller than 5 millimeters long. They can be found in industrial waste and beauty products or may form during the degradation of larger pieces of plastic waste. The ocean contains somewhere between 50 and 75 trillion pieces of these micro- and larger plastics, according to estimates by UNESCO's Ocean Literacy Portal, which end up in our food and waterways.
These plastic particles contain chemicals that can interrupt our body's natural release of hormones, potentially increasing our risk of reproductive disorders and certain cancers. They can also carry toxins on their surface like heavy metals.
With so many of these tiny particles in the ocean, it is perhaps unsurprising that some have been drawn up into the atmosphere. However, their presence in high altitude environments has been largely unstudied—until now.
In a recent study, published in the journal Environmental Chemistry Letters, researchers from Waseda University in Japan analyzed cloud water from the summits of Mount Fuji and Mount Oyama—between 4,200 and 12,400 feet in the air—to investigate whether these tiny plastic particles were present at such high altitudes. And they were.
The microplastics were highly fragmented, at a concentration of around 6.7 to 13.9 pieces per liter of cloud water. In total, nine different types of plastic polymer and one type of rubber were identified. Most of these microplastics contain molecules that are able to bond with water, suggesting that they may play a role in cloud formation, acting as the seed at the center of the cloud around which water vapor can condense.
Scientifically, this is called a cloud condensation nucleus, and its presence has the potential to influence weather patterns around the world.
"Microplastics in the free troposphere are transported and contribute to global pollution," Hiroshi Okochi, who led the study, said in a statement. "If the issue of 'plastic air pollution' is not addressed proactively, climate change and ecological risks may become a reality, causing irreversible and serious environmental damage in the future."
This discovery adds to previous studies, demonstrating the presence of microplastics in rainwater. For example, a study by Utah State University in 2020 found that more than 1,000 metric tons of plastic particles fall every year within protected areas in the south and central western U.S.
These airborne plastics not only contribute to cloud formation but may also play a role in exacerbating global warming by absorbing, emitting or scattering incoming sunlight. This radiation can also accelerate the breakdown of these particles, releasing additional greenhouse gasses in the process.
"Airborne microplastics are degraded much faster in the upper atmosphere than on the ground due to strong ultraviolet radiation, and this degradation releases greenhouse gases and contributes to global warming," Okochi said. "As a result, the findings of this study can be used to account for the effects of airborne microplastics in future global warming projections."
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Pandora Dewan is a Senior Science Reporter at Newsweek based in London, UK. Her focus is reporting on science, health ... Read more
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