How Microplastics in the Air Contribute to Climate Change

Microplastic and nanoplastic particles (MNPs) have become prevalent in natural and built environments. EPA researchers define microplastics, or MPs, as plastic particles ranging in size from 5 millimetres (mm), about the size of a pencil eraser, to 1 nanometre (nm).

Through plastic pollution, these microplastic and nanoplastic particles spread across our planet from the Antarctic tundra to tropical coral reefs and have been found in food, beverages, and human and animal tissues.

They are also found in our oceans, rivers, land, and the atmosphere, raising concerns about how they may harm humans and the environment. However, their presence in the atmosphere and their effect on the planet’s warming remain uncertain.

A new study, “Atmospheric warming contributions from airborne microplastics and nanoplastics”, published in Nature Climate Change in May 2026, reveals that Microplastic and nanoplastic particles (MNPs) floating in the atmosphere contribute to global warming, particularly those that are colourful.

The study, led by researchers at Fudan University in China, notes that since 2015, when scientists first found that MNPs can combine with rain and dust, they have also been detected in the atmosphere worldwide, and their presence can alter how sunlight reaches Earth. This effect is expected to increase as plastic pollution worldwide worsens.

By combining a radiative transfer model with lab measurements of how these particles interact with light and simulated global distributions, researchers found that darker-coloured microplastics absorb light about 75 times more strongly than clean, unaltered particles.

As these MNPs age in the atmosphere, their optical properties stay mostly unchanged. White MNPs turn yellow over time due to UV exposure and oxidants, darkening them and hence increasing their light absorption.

Meanwhile, as red or coloured MNPs age, they fade or undergo bleaching, reducing their absorption. Hence, the effects of white and coloured MNPs as they age cancel each other out, leading to minimal net change in their total radiative forcings.

The study’s model estimates that global surface concentrations reach 4.18 microplastic particles per cubic metre and 3.67 nanograms per cubic metre for nanoplastics. Based on these levels, MNPs contribute an average direct radiative forcing of 0.039 ± 0.019 watts per square metre. To put this warming into perspective, it is equivalent to 16% of that from black carbon (soot).

This warming effect is even greater in some regions, such as the North Pacific Subtropical Gyre, reaching around 1.34 watts per square metre, or 4.7 times the warming of black carbon.  

The findings reveal “a long-overlooked link” between plastics and climate change, said study co-author Hongbo Fu, a researcher at Fudan University in China, at a press conference. Plastics are not just an environmental pollutant. “They can also act as a heating agent in the atmosphere,” he said (Morgensen, 2026).

In addition to the study’s findings that microplastic and nanoplastic particles (MNPs) contribute to global warming, plastic production also releases greenhouse gases, highlighting plastic pollution’s role as a double climate threat.

This underscores the need to reduce our dependence on and production of plastic, which is usually made from chemicals sourced from fossil fuels. This makes both industries – plastic and fossil fuels – deeply connected.

To learn more about the study, please explore the links provided below.