Microplastics could change Earth’s climate, new study reveals

Scientists at Penn State University have identified that microplastics in the atmosphere could influence Earth’s climate. A study published in Environmental Science and Technology: Air reveals that these tiny plastic particles can act as ice nucleators in clouds, impacting precipitation, weather and perhaps even aviation. Although the precise effects remain unclear, the results highlight the possibility that microplastics play an underappreciated role in climate dynamics.

Microplastics detected in remote and extreme locations

According to the studyMicroplastics (particles measuring less than five millimeters) have been discovered around the world, from deep ocean trenches to high-altitude clouds. Penn State research now adds that airborne microplastics, found even in remote mountainous regions, may contribute to climate change by altering cloud structures. Professor Miriam Freedman, lead author and professor of chemistry at Penn State, said the study highlights the need to understand the interactions of microplastics with the atmospheric system, particularly in cloud formation processes.

Laboratory analysis reveals how microplastics behave in ice formation

The study further mentions that in the experiments, the research team examined how four types of microplastics – low density polyethylene (LDPE), polypropylene (PP), polyvinyl chloride (PVC) and polyethylene terephthalate ( PET) – affect ice formation. The particles would be suspended in water droplets and cooled, revealing that droplets laden with microplastics froze at higher temperatures than those without them. Lead author Heidi Busse, a Penn State graduate researcher, reported that the presence of microplastics made it possible to freeze up to 10 degrees warmer, meaning such particles could promote the nucleation of cloud ice at milder temperatures.

Implications for climate models and precipitation

Although the full impact of microplastics on climate remains unclear, Dr Freedman suggests they could change precipitation patterns by influencing the properties of clouds. In areas with high levels of microplastics, the dispersion of water among many particles could cause smaller droplets to form, thereby delaying precipitation, but potentially leading to heavier precipitation once the droplets coalesce.

Environmental aging and future research directions

Environmental factors, such as exposure to sunlight and atmospheric chemicals, also appear to affect the ice-forming potential of microplastics, with aged PVC exhibiting increased nucleation capacity. Future research will focus on additives in plastics, which could reveal other effects on Earth’s climate.