Plastic waste discharge to the global ocean constrained by seawater observations

Yanxu Zhang; Peipei Wu; Ruochong Xu; Xuantong Wang; Lili Lei; Amina T Schartup; Yiming Peng; Qiaotong Pang; Xinle Wang; Lei Mai; Ruwei Wang; Huan Liu; Xiaotong Wang; Arjen Luijendijk; Eric Chassignet; Xiaobiao Xu; Huizhong Shen; Shuxiu Zheng; Eddy Y Zeng

doi:10.1038/s41467-023-37108-5

Plastic waste discharge to the global ocean constrained by seawater observations

Nat Commun. 2023 Mar 13;14(1):1372. doi: 10.1038/s41467-023-37108-5.

Authors

Yanxu Zhang^#^{1

2}, Peipei Wu^#³, Ruochong Xu³, Xuantong Wang³, Lili Lei⁴, Amina T Schartup⁵, Yiming Peng³, Qiaotong Pang³, Xinle Wang³, Lei Mai⁶, Ruwei Wang⁶, Huan Liu⁷, Xiaotong Wang⁷, Arjen Luijendijk^{8

9}, Eric Chassignet¹⁰, Xiaobiao Xu¹⁰, Huizhong Shen¹¹, Shuxiu Zheng¹², Eddy Y Zeng¹³

Affiliations

¹ School of Atmospheric Sciences, Nanjing University, 210023, Nanjing, China. zhangyx@nju.edu.cn.
² Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, 210023, Nanjing, China. zhangyx@nju.edu.cn.
³ School of Atmospheric Sciences, Nanjing University, 210023, Nanjing, China.
⁴ School of Atmospheric Sciences, Nanjing University, 210023, Nanjing, China. lililei@nju.edu.cn.
⁵ Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA.
⁶ Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, 511443, Guangzhou, China.
⁷ State Key Joint Laboratory of ESPC, State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, School of Environment, Tsinghua University, Beijing, China.
⁸ Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands.
⁹ Hydraulic Engineering, Deltares, Delft, Netherlands.
¹⁰ Center for Ocean-Atmospheric Prediction Studies (COAPS), Florida State University, Tallahassee, FL, USA.
¹¹ School of Environmental Science and Technology, Southern University of Science and Technology, Shenzhen, Guangdong, China.
¹² College of Urban and Environmental Sciences, Peking University, Beijing, China.
¹³ Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, 511443, Guangzhou, China. eddyzeng@jnu.edu.cn.

^# Contributed equally.

Abstract

Marine plastic pollution poses a potential threat to the ecosystem, but the sources and their magnitudes remain largely unclear. Existing bottom-up emission inventories vary among studies for two to three orders of magnitudes (OMs). Here, we adopt a top-down approach that uses observed dataset of sea surface plastic concentrations and an ensemble of ocean transport models to reduce the uncertainty of global plastic discharge. The optimal estimation of plastic emissions in this study varies about 1.5 OMs: 0.70 (0.13-3.8 as a 95% confidence interval) million metric tons yr^-1 at the present day. We find that the variability of surface plastic abundance caused by different emission inventories is higher than that caused by model parameters. We suggest that more accurate emission inventories, more data for the abundance in the seawater and other compartments, and more accurate model parameters are required to further reduce the uncertainty of our estimate.

Grants and funding

42177349/National Natural Science Foundation of China (National Science Foundation of China)