Climate change and microplastics: a two-way interaction

Microplastics (MPs) maintain a bidirectional relationship with climate change, simultaneously contributing to global warming and being influenced by it. The production, use, and disposal of plastics generate substantial greenhouse gas (GHG) emissions, from the high energy demands of manufacturing to their degradation in the environment. In aquatic ecosystems, MPs reduce phytoplankton activity, compromising primary productivity and decreasing CO2 uptake. In both terrestrial and aquatic systems, MPs disrupt biogeochemical cycles, influencing GHG emissions and exacerbating global warming. Atmospheric MPs affect regional and global radiative balances by altering Earth’s cooling processes and contributing to cloud formation and dust transport. In polar environments, the deposition and subsequent release of MPs from melting ice accelerates climate feedback, exposing new areas to further warming. MPs also alter microbial communities, affecting oxygen consumption and GHG release during soil organic matter decomposition. As global temperatures rise, plastic fragmentation intensifies, and extreme weather events increase MP dispersion. Thus, a vicious cycle emerges between global warming and pollution, wherein both factors mutually reinforce each other, undermining natural systems and the planet’s climate stability. This article aims to compile and synthesize current scientific knowledge to provide an overview that supports the development of mitigation measures addressing the challenges posed by MPs in the context of global warming, through a discussion of the characteristics of various Earth compartments, including the atmospheric, sedimentary, aquatic, and biological ones.