Microplastics in Clouds Could ‘Modify the Climate,’ Study Finds

Microplastics are everywhere. They have been found inside fish at the bottom of the ocean, in the Pyrenees mountains and on Arctic sea ice, but how they are transported remains largely a mystery.

A new study by Japanese researchers has confirmed the presence of microplastics in clouds, where they are likely to be having effects on the climate that have yet to be fully realized.

In the study, the researchers climbed Mount Oyama and Mount Fuji to collect water from mist-enveloped peaks. They then used advanced imaging to determine the chemical and physical properties of the samples, reported AFP.

“Overall, our findings suggest that high-altitude microplastics could influence cloud formation and, in turn, might modify the climate,” the scientists wrote in the study.

The study, “Airborne hydrophilic microplastics in cloud water at high altitudes and their role in cloud formation,” was published in the journal Environmental Chemistry Letters.

Through their analysis, the research team identified nine unique polymer types, as well as one type of rubber, in the samples of airborne microplastics. The microplastics ranged from 7.1 to 94.6 micrometers. An average human hair has a width of 80 micrometers.

Each liter of the liquid cloud vapor was found to contain from 6.7 to 13.9 microplastic pieces.

An abundance of “hydrophilic” polymers — those that are drawn to water — were found, which suggests that they play a major part in climate systems through rapid cloud formation.

The authors of the study explain that plastics start out being hydrophobic, but become hydrophilic following prolonged ultraviolet light exposure, Euronews Green reported.

Some of the samples collected had an abundance of polymers, suggesting the polymers may have served as “condensation nuclei” — tiny particles that water vapor condenses on in the atmosphere — for cloud water and ice.

“Microplastics in the free troposphere are transported and contribute to global pollution,” said Hiroshi Okochi of Waseda University, who was lead author of the study, as reported by Euronews Green. “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.”

When microplastics — defined as plastic particles that are less than five millimeters in size and originate from things like synthetic car tires, textiles, industrial effluent and personal care products — reach the upper atmosphere and are exposed to the ultraviolet radiation of the sun’s rays, it degrades them, contributing to greenhouse gases, Okochi said, according to AFP.

The tiny particles have been linked with widespread environmental damage, as well as cancers and a range of adverse health impacts related to the lungs and heart.