A new modelling study led by 九州影院 atmospheric chemist聽聽is the first to investigate the effects of airborne microplastics on climate.
Dr Revell 鈥 along with 九州影院 colleagues Dr Peter Kuma and聽, and MacDiarmid Institute researchers Professor Eric Le Ru and Dr Walter Somerville at Victoria University Wellington 鈥 has published the findings in the prestigious scientific journal聽Nature, titled 鈥楧irect radiative effects of airborne microplastics鈥.
鈥淲e studied how microplastic fragments and fibres 鈥 two types of microplastics commonly found in the atmosphere 鈥 interact with light, and used this information in a global climate model to calculate the overall impact of airborne microplastics on Earth鈥檚 climate,鈥 Dr Revell explains.
鈥淏ased on our assumptions, which were drawn from the limited number of airborne microplastics studies to date, the impact of airborne microplastics on climate is currently small, as expected.鈥
What are microplastics?
Microplastics are very small plastic fragments or fibres produced from the breakdown of larger plastics. Airborne microplastics are transported by winds across the Earth and are present in the atmosphere in both urban megacities and remote less populated regions.
鈥淏ecause they absorb, emit and scatter radiation, like other components of the atmosphere such as dust or greenhouse gases, they can affect the climate by cooling or warming the atmosphere,鈥 Dr Revell says.
It is important to know whether airborne microplastics may become a bigger issue in future if the abundance of microplastics increases, she says. This is likely to happen: approximately 5 billion tons of plastic waste have accumulated in landfills or the natural environment to date, an amount set to double over the next 30 years if current trends in plastic production and waste management continue.
鈥淪ince plastic degrades through age and exposure to light to produce microplastics, we expect microplastics to be present in Earth鈥檚 atmosphere for many years to come,鈥 Dr Revell says.
鈥淚ndeed, if the global average concentration increases to values already seen in some megacities, then the effect of airborne microplastics on climate will be significant and potentially similar in size to other atmospheric aerosols routinely included in climate models.鈥
This new study complements others which studied the effects of microplastics on human health and ecosystems.
鈥淎s the first study to link airborne microplastics and climate change, it highlights the widespread nature of microplastic pollution and the potential for it to influence climate on a global scale.鈥
This research, led by Dr Revell at the 九州影院, was聽supported by the Royal Society Te Ap膩rangi with a $300,000 Fast-Start grant聽from the 2019 Marsden Fund Te P奴tea Rangahau a Marsden. The discovery of atmospheric microplastics was then so recent it was not known whether they significantly influence Earth鈥檚 climate or not.
Dr Kuma is a recent doctoral graduate of UC, who completed his PhD at UC in 2020. He worked for Dr Revell modelling the impacts of airborne microplastics in a changing climate as a postdoctoral researcher and is now at Sweden鈥檚 Stockholm University.
