A growing plastic smog, now estimated to be over 170 trillion plastic particles afloat in the world's oceans-Urgent solutions required

Abstract

As global awareness, science, and policy interventions for plastic escalate, institutions around the world are seeking preventative strategies. Central to this is the need for precise global time series of plastic pollution with which we can assess whether implemented policies are effective, but at present we lack these data. To address this need, we used previously published and new data on floating ocean plastics (n = 11,777 stations) to create a global time-series that estimates the average counts and mass of small plastics in the ocean surface layer from 1979 to 2019. Today's global abundance is estimated at approximately 82-358 trillion plastic particles weighing 1.1-4.9 million tonnes. We observed no clear detectable trend until 1990, a fluctuating but stagnant trend from then until 2005, and a rapid increase until the present. This observed acceleration of plastic densities in the world's oceans, also reported for beaches around the globe, demands urgent international policy interventions.

Fig 1. Map of sample station distribution.

A total of 11,777 stations were used to model a global time trend.

Fig 2. Count for each year for each basin.

Some ocean basins are overrepresented (e.g., North Atlantic and North Pacific), whereas others have very few observations at a minority of time points (e.g., Indian, South Atlantic, South Pacific, and Mediterranean).

Fig 3. Global trend from 1979 to 2019 with confidence intervals.

Change in the abundance of ocean plastic through time in trillions of particles or tens of thousands of metric tonnes using a smoothing spline and a generalized additive model. Central line is the model fit; confidence intervals are 2 times the standard error of the model.

Fig 4. International policy interventions and maritime law.

A cluster of binding international policy and maritime-law interventions preceding the millennium may have played a role in slowing the increasing trend of plastic waste in the OSL.