Study: Airborne Microplastics Warm Atmosphere

A new study published in the journal Nature Climate Change reveals that microplastics and nanoplastics suspended in the atmosphere act as warming agents by absorbing more sunlight than they reflect, contributing to global temperatures at about one-sixth the level of black carbon, a pollutant known as soot.

Researchers led by a team at Fudan University in China, with coauthor Drew Shindell, a professor of earth science at Duke University, analyzed the optical properties of these particles in laboratory tests. They examined microplastics and nanoplastics of various colors and sizes, finding that black, yellow, blue and red particles absorb sunlight far more strongly than white or uncolored ones, with absorption coefficients nearly 75 times higher for colored particles. Combining these measurements with global atmospheric simulations, the scientists calculated a direct radiative forcing of 0.039 plus or minus 0.019 watts per square meter from the particles, equivalent to 16 percent of black carbon's effect.

The warming influence varies by region. In the North Pacific Subtropical Gyre, an area with high plastic concentrations, the particles' forcing reaches up to 1.34 watts per...