Since 1950, plastics production and use has increased 230-fold. However, this trend comes with environmental and health risks, especially for plastics intended for short-lived applications. 31% of plastics produced are for packaging – often single-use and with an average six-month lifespan – which contributes significantly to waste generation and can easily end up in the environment. It may therefore not be a surprise that 83% of plastics produced in 2020 ended up as waste (360 million tonnes [Mt], relative to 435 Mt produced).
Curbing plastic production and better managing its waste are key to ocean health. What do the latest OECD Environment data on plastic pollution and the ocean tell us?
Over one million tonnes of plastic ends up in the ocean each year
Plastic waste that isn’t safely managed may up in land, air and aquatic ecosystems. Plastic pollution can be found in all facets of the ocean, from shallow coastal waters to the depths of the Mariana Trench. It can reach this system directly, as with lost or discarded fishing gear and extreme weather events, such as heavy rainfall, flooding and droughts. Plastic pollution can also enter the ocean from land-based sources, trickling in from beach litter or entering from rivers, the arteries of our planet. In 2020 alone, 1.4 Mt of plastics flowed from rivers into the ocean. Without additional policy interventions to mitigate plastic pollution, the flow of plastics from rivers to oceans is on track to more than double (to 3.6 Mt) by 2060.
Plastics can remain in the ocean for decades
Most plastics do not biodegrade and consequently may pollute natural habitats for centuries, during which time they may jeopardise animal welfare, human health and ecosystem integrity. Between 1950 and 2020, 32 Mt of plastics accumulated in the ocean – the weight of over 200 000 blue whales, the world’s largest animal. Plastics with a greater density than seawater sink, accumulating in deep-sea canyons and trenches. Meanwhile, floating plastics are transported by waves, wind and currents and may end up aggregating, as in the Great Pacific Garbage Patch. The greatest proportion ends up near shorelines.
Plastics can break into microplastics (< 5 mm in diameter), at least 15 trillion particles (93 000 tonnes) of which are present just on the ocean surface. Due to their small size, microplastics can be easily ingested or inhaled by organisms, increasing risks to marine ecosystems. Microplastics may also interfere with plankton’s ability to store carbon, undermining the role oceans play in storing carbon dioxide from the atmosphere and mitigating climate change.
Without additional policy action, the buildup of ocean plastics will quadruple
Under a business-as-usual scenario, the amount of plastics accumulating in the ocean is projected to reach 76 Mt by 2040 and 141 Mt by 2060. These data suggests that in the span of two decades, the quantity of plastics in the ocean will match all historically accumulated plastics in this realm. As the volume of plastics entering the ocean balloons, so too will risks to human health and the environment.
Recommendations for policymakers
Ramp up ambitious policies. Globally ambitious action across the plastics lifecycle can prevent up to 61 Mt of plastics from being added to existing stocks of ocean plastic pollution in 2060. This includes policies that curb plastics production and demand, promote eco-design, enhance recycling, and improve waste collection and treatment.
Improve waste and litter management. In countries where waste collection and sorting systems are more nascent, proper infrastructure can improve environmentally sound plastics management. An increase in street sweeping, waste collection, sorting and recycling can reduce the portion of plastics that is not properly managed and enters the ocean.
Consider remedial interventions. Even under an ambitious policy scenario, stocks of plastic waste in oceans could reach 79 Mt by 2060. Clean-up interventions are important to mitigate environmental risks, especially in pollution hotspots and in developing countries most affected by plastic pollution. These interventions can also help gather data and inform policy efforts. At the same time, attention should be paid to their potential environmental impacts and cost efficiency.
