Proposed definition in UNEP/PP/INC.3/INF/1: Biological process influenced by the physicochemical (temperature, humidity, pH) and microbiological variables (quantity and nature of microorganisms) of the environment that results in the formation of water, carbon dioxide (CO2) and/or methane (CH4), energy and by-products—including residues, new biomass. Developed and modified from a meaning of ‘degradation’ contained in From Pollution to Solution: A global assessment of marine litter and plastic pollution (UNEP 2021).