Global environmental plastic dispersal under OECD policy scenarios toward 2060.

Recent studies and OECD (Organization for Economic Cooperation and Development) reports provide roadmaps to reduce dispersal of mismanaged plastic waste to aquatic environments. Here, we use a coupled land-ocean-atmosphere model to simulate global plastic and microplastic dispersal for different OECD policy scenarios toward 2060. We establish a global plastic budget for the year 2015, with revised estimates of the total marine plastic pool of 263 teragrams (Tg, million tons), and land to sea plastic transport of 14 Tg per year, implying four to nine times larger leakage than OECD estimates. Model simulation of two ambitious policy scenarios show a peak in land to sea transport of total plastics of 23 Tg per year around 2045 and a decrease thereafter. Environmental concentrations of small microplastics remain high after 2060 due to continuous fragmentation of legacy mismanaged waste on land and indicate the need for remediation of legacy terrestrial plastic waste in policy instruments.