Plastic waste discharge to the global ocean constrained by seawater observations

The article discusses how marine plastic pollution poses a potential threat to the ecosystem and how the sources and their magnitudes remain largely unclear. The authors 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 orders of magnitudes: 0.70 (0.13-3.8 as a 95% confidence interval) million metric tons yr-1 at the present day. They 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.

Review questions: – What are the sources of ocean plastic waste? – What is the global flux of plastic waste emitted to the ocean? – What are some limitations in estimating the emissions of plastic debris to the global ocean? – How does this study estimate plastic emissions in the ocean? – What is the optimal estimation of plastic emissions in this study? – How does this study suggest reducing uncertainty in estimating plastic emissions? – What is an ensemble of ocean transport models? – What are some potential threats posed by marine plastic pollution? – How does this study suggest reducing uncertainty in estimating plastic emissions? – How can we encourage companies to reduce their use of plastics? – What are some ways that we can encourage governments to take action on marine plastic pollution?