The sky is no limit - 29th January 2024

Microplastics in clouds may be altering Earth's climate, according to a study by a team of Japanese scientists.

It seems that the sky is no limit for these tiny polymers. Despite being previously detected in the depths of the oceans, volcanic rock, and even human bodies, they had never been observed in clouds before being identified in a study led by a team from Waseda University.

The sample, gathered using a string type passive cloud collector above Mount Fuji, was found to contain 6.7 to 13.9 pieces of 9 types of polymers, including polyethylene, polycarbonate and black rubber, all measuring less than 5 millimetres.

Alarmingly, the research, led by Hiroshi Okochi, indicates that the degradation of airborne microplastics in clouds releases harmful greenhouse gases into the atmosphere exacerbating the effects of climate change.

It seems that these microplastics may even influence cloud formation as their normally hydrophobic properties become hydrophilic when exposed to the excess UV rays in sunlight, potentially leading to the creation of condensation nuclei for ice and water droplets.

Through precipitation, microplastics pervade the land, watercourses and agricultural soil and ultimately our food chain. Humans and animals alike consume these microscopic elements which then infiltrate hearts, brains and lungs and have recently been detected in the bloodstream.

Whilst the effects of microplastics are not fully known, previous studies have shown links to cancer and irritable bowel syndrome in humans, whilst stress, inflammation and reproductive disorders were observed in mice fed the tiny polymers.

What remains uncertain is how these microscopic elements make their way into clouds, but the finger has been pointed at aerosols, waves churning up ocean spray, and dust kicked up by cars, as likely culprits.

Despite the numerous positives that the use of plastics have afforded us, it is clear that we are still in the dark about their pervasive nature and nature on Earth can wait no longer. "If the issue of plastic air pollution is not addressed proactively," warns Okochi, "climate change and ecological risks may become a reality, causing irreversible and serious environmental damage in the future."