The climate impact of plastic pollution is negligible – production of new plastics is the larger problem
Plastics release CO2 throughout their lifecycle; during the extraction of materials used in their production, through plastic-carbon leaching in the marine and terrestrial environment, and during their different end-of-life scenarios, which include recycling, landfill, and incineration. We used the University of Victoria Earth System Climate Model to quantity the effects on atmospheric CO2 and the ocean carbon cycle by using upper-bound estimates of carbon emissions from marine plastic–carbon leaching or land-based incineration. We find that CO2 emitted from plastic waste has an insignificant effect on the Earth's global climate system. CO2 emissions associated with plastic production and incineration have a greater impact on climate but are still dwarfed by emissions associated with the combustion of fossil fuels and other anthropogenic sources.
Reference: Gurgacz, N.S., Kvale, K., Eby, M. & Weaver, A.J. (2023). Impact of plastic pollution on atmospheric carbon dioxide. FACETS, 8, 1-7. https://doi.org/10.1139/facets-2023-0061