Mismanaged waste, and in particular terrestrial and marine plastic pollution, represent some of the most pressing environmental issues. Yet, on a global scale waste generation has only been quantified for the year 2015. Estimates of macroplastic flow into environment and oceans therefore only exist for the year 2015 and into the future.  Additionally, estimates of riverine and terrestrial plastic emission into the ocean are highly uncertain and strongly surpass the observed amount of plastic in the ocean. Here we use machine learning to estimate country-specific waste collection from 1990-2019, showing an increase in globally collected waste from about 1.1 billion ton in 1990 to 1.9 billion tons in 2019. The amount of plastic in the waste stream has increased from about 100 mio tons in 1990 to 400 mio tons in 2019, albeit with substantial uncertainties. We then estimate that between 40 and 1300 mio tons of macroplastic have leaked into the environment cumulatively since 1990.  We next use observed macroplastic pollution in rivers to constrain the plastic flow into the ocean. Preliminary results suggest that between 0.1 and 16 mio tons of plastic have likely been transported to the ocean cumulatively, with mid-point estimates of 0.95-3.7 mio tons. Overall, our results indicate that due to a lack of observational constraints, previous parameterizations of plastic transport over land have resulted in significant overestimates.  

Primary Presenter: Charlotte Laufkotter, University of Bern (c.laufkoetter@gmail.com)

Authors:

Charlotte Laufkötter, University of Bern  (c.laufkoetter@gmail.com)

Fabio Benedetti, ETH Zürich  (fabio.benedetti@usys.ethz.ch)

Daniel Gonzalez, University of Cádiz and European University of the Seas  (daniel.gonzalez@uca.es)

Kevin Lang, ETH Zürich  (langk@mail.ch)

Victor Onink, University of Bern  (victor.onink@googlemail.com)

Caspar Roebroek, ETH Zürich, European Commission Joint Research Centre  (roebroek.jasper@gmail.com)

Tim van Emmerik, Hydrology and Quantitative Water Management Group, Wageningen University  (tim.vanemmerik@wur.nl)

Meike Vogt, ETH Zürich  (meike.vogt@env.ethz.ch)