Airborne Microplastics Fuel Global Warming
A new study reveals airborne microplastics contribute to global warming, exerting significant radiative forcing, particularly in the North Pacific.
Lauren Collins ·
Airborne Microplastics Contribute to Warming Atmospheric microplastic and nanoplastic particles (MNPs) contribute to global warming, according to a study published in Nature Climate Change. Researchers utilized a radiative transfer model, experimental optical properties, and simulated atmospheric distributions to quantify the direct radiative forcing (DRF) of these airborne particles. The study found that MNPs exert a mean DRF of 0.039 ± 0.019 W m−2 globally, equivalent to 16.2% of the forcing attributed to black carbon.
The analysis revealed that colored MNPs exhibit strong light absorption, with absorption coefficients 74.8 times higher than pristine particles. Despite atmospheric aging causing minimal net optical change due to offsetting effects of yellowing and bleaching, global surface concentrations reached 4.18 MP m−3 for microplastics and 3.67 ng m−3 for nanoplastics. These concentrations drive significant regional warming effects.
Regionally, the DRF from MNPs peaks over the North Pacific Subtropical Gyre, reaching approximately 1.34 W m−2. This regional forcing is 4.7 times greater than that of black carbon in the same area, identifying MNPs as a previously unrecognized climate forcing agent. The findings indicate a new dimension to understanding anthropogenic impacts on atmospheric radiative balance.