Plastic encompasses a diverse range of materials with different properties, from everyday items like bags and bottles to specialized products used in various industries. Plastic pollution is a widespread problem, with approximately 10 million tonnes of plastic leaking into the ocean annually, causing a severe environmental crisis. However, accurately measuring and forecasting this issue is complex due to technical limitations and fragmented assessment efforts. Addressing plastic pollution requires the use of appropriate metrics to guide and prioritize action at different levels, including product design, infrastructure, and policies.

This review provides an overview of the plastic pollution issue, emphasizing the quantities of plastic entering oceans, discussing knowledge gaps and challenges in assessing and forecasting plastic leakage, and emphasizing the urgent need for action.