Airborne microplastics could directly affect climate change, scientists find
Tiny fragments of plastic floating in the air could have a direct impact on climate change, a new study had found although just what damage they could do remains to be seen. The New Zealand research, the first of its kind, and published in international science journal Nature on Thursday, has modelled what kind of impact airborne microplastics any pieces of plastic less than five millimetres long could have on the climate. The study was lead by University of Canterbury atmospheric chemist Dr Laura Revell, who earlier this year found microplastic particles in New Zealand air for the first time. Her findings caused at least one regional council to press the Government on whether it needed to take action. READ MORE: * Quarter of fish in Hauraki Gulf have microplastics in their guts, study finds * Bottle-fed babies may consume millions of microplastic particles, research suggests * Blown by the wind, microplastic pollution discovered in pristine mountain peaks Revell said the new study was about understanding how those airborne particles interact with the atmosphere. We studied how microplastic fragments and fibres two types of microplastics commonly found in the atmosphere interact with light, and used this information in a global climate model to calculate the overall impact of airborne microplastics on Earths climate. Other types of aerosol have been shown to either scatter or absorb sunlight, she said. Some, like dust or sea spray, act like tiny disco balls and reflect sunlight back to space, which has a cooling effect. Others, like soot, are good at absorbing sunlight and have a warming effect. But when it comes to microplastics, it turns out that they do both. Overall, airborne microplastics are efficient at scattering sunlight, which implies a cooling effect on climate. However, they can also absorb radiation emitted by the Earth, meaning that they contribute, in a very small way, to the greenhouse effect. With airborne microplastics only discovered a few years ago, Revell said their data pool was limited but they calculated the tiny particles were already starting to have an impact. Given the amount in the atmosphere is very small, currently the impact is very small. [But] as they accumulate over time, they will become more significant. Five billion tonnes of plastic waste have built up in landfills and the environment to date, she said, and a figure that is projected to double over the next three decades if current trends continue. As they break down over time, microplastics will become a bigger issue. Microplastics are damaging to human health ... and theyre harmful for our ecosystems and our oceans. Plastic was a great success when it was invented ... but Im sure the original inventors wouldve been shocked if they knew what it could do down the line. Revell said the world needed to take serious action to address microplastics pollution, including rethinking how much plastic is produced, and how we manage our waste. [Or] the abundance of microplastics will continue to increase, and airborne microplastics could contribute to future changes in climate. Another Canterbury-based study, published in the NZ Journal of Marine and Freshwater Research on Thursday, reveals for the first time not only that microplastics are in New Zealands wastewater, but that they make their way into the environment through treatment plants. Researchers regularly sampled effluent from three wastewater treatment plants in Christchurch, Lyttelton, and Kaiapoi, and found between them around 240,000 tiny pieces of plastic wash out to sea each day. One of the most common types detected was polyester, a common material in synthetic clothing. Treatment plants like those in the study are not currently designed to remove microplastics from sewage, and plastic pollution could be a big issue for marine and coastal environments. One study earlier this year found a quarter of fish in the Hauraki Gulf had microplastics in their guts , while another found them in every single sediment sample taken across the Bay of Plenty with particularly high concentrations in shellfish.