More than 1000 rivers account for 80% of global riverine plastic emissions into the ocean

Plastic waste increasingly accumulates in the marine environment, but data on the distribution and quantification of riverine sources required for development of effective mitigation are limited. Our model approach includes geographically distributed data on plastic waste, land use, wind, precipitation, and rivers and calculates the probability for plastic waste to reach a river and subsequently the ocean. This probabilistic approach highlights regions that are likely to emit plastic into the ocean. We calibrated our model using recent field observations and show that emissions are distributed over more rivers than previously thought by up to two orders of magnitude. We estimate that more than 1000 rivers account for 80% of global annual emissions, which range between 0.8 million and 2.7 million metric tons per year, with small urban rivers among the most polluting. These high-resolution data allow for the focused development of mitigation strategies and technologies to reduce riverine plastic emissions.

Automated summary

Research shows that plastic waste in the marine environment mainly comes from rivers, with a model approach predicting the probability of plastic waste entering the ocean and identifying regions likely to emit plastic into the ocean. It is estimated that over 1000 rivers globally contribute to 80% of plastic waste emissions, with small urban rivers being the most polluting.