More than 9.1 billion tons of plastic have been manufactured since the material was initially mass-produced in the 1950s, according to "the first global analysis of all mass-produced plastics," which reports the majority has ended up in landfills or natural settings.
Global production of plastic has grown rapidly in recent decades, surpassing many other man-made materials, yet there has been a lack of information about its fate - what proportion is recycled, incinerated or discarded. Such knowledge could help offer better solutions to the challenges posed by the global increase in plastics production and use.
Plastic's largest market is packaging, an application whose growth was accelerated by a worldwide shift from reusable to single-use containers. As a result, the share of plastics in municipal solid waste increased from less than 1% in 1960 to more than 10% by 2005 in middle- and high-income countries, and plastic debris has been found in all major ocean basins in the world. The same properties that make plastics so useful in everyday life (such as durability) also make them difficult to break down.
Here, Roland Geyer and colleagues report that, as of 2015, of the nearly 7 billion tons of plastic waste generated, only 9% was recycled, 12% incinerated (using thermal treatments such as combustion or pyrolysis, decomposition under high temperatures), and 79% accumulated in landfills or the environment.
The authors note that recycling merely delays, rather than avoids, plastic disposal, unless it reduces new plastic production. Incinerating plastic can have negative environmental and health effects. What's more, none of the commonly used plastics are biodegradable; in other words, tossed plastics accumulate, rather than decompose.
If current trends continue, the researchers predict over 13 billion tons of plastic waste will be discarded in landfills or in the environment by 2050.
Video courtesy Carla Schaffer / AAAS
Featured image credit: Paolo Margari (Flickr)