Some 60 percent of all the plastics that have ever been manufactured have been landfilled or remain as litter in the environment, according to a new study. Less than 10 percent have been recycled.
The study claims to be the first-ever global attempt to track the fate of all plastics ever manufactured.
The authors, who are all active in research on plastics pollution in the ocean, analyzed other research and literature to attempt to put some baseline data to questions about the environmental impact of rapidly rising use of plastics.
The study estimates, for example, that about 30 percent of the 8.3 billion metric tons of plastics ever made are still in use.
Of the remaining 6.3 billion metric tons of plastics that have ended their useful lives, the study estimated that about 12 percent has been incinerated but nearly 80 percent has gone into garbage dumps or remains in the environment.
While the study is mostly an analysis of production data and disposal trends, it cautioned that little is known about the long-term impacts of plastics production growth, which it said has “substantially outpaced any other manufactured material.”
“Without a well-designed and tailor-made management strategy for end-of-life plastics, humans are conducting a singular uncontrolled experiment on a global scale, in which billions of metric tons of material will accumulate across all major terrestrial and aquatic ecosystems on the planet,” it said.
“The same properties that make plastics so versatile in innumerable applications — durability and resistance to degradation — make these materials difficult or impossible for nature to assimilate,” the study said.
The study was published July 19 in the journal Science Advances, and was written by Roland Geyer of the University of California at Santa Barbara, Jenna Jambeck of the University of Georgia and Kara Lavender Law of the Sea Education Association in Woods Hole, Mass.
The Washington-based American Chemistry Council said it welcomed the study and discussions about environmental benefits behind rising plastics use. It pointed to other research that showed that plastics reduce environmental costs by four times compared to other materials.
“Demand for plastics has grown in parallel with population growth, particularly in parts of the world where large numbers of people are rapidly moving out of poverty,” ACC said. “Many experts agree that expanded waste management infrastructure is the key to addressing sustainable use of these resources.”
ACC said plastics makers are working closely with governments and other partners to improve waste management and increase recycling and energy conversion of plastics when recycling is not feasible.
“Lightweight plastics offer significant environmental benefits throughout the life cycle of many products and packages, but we fail to maximize those benefits if we don't manage these resources after we use them,” ACC said.
The study noted wide variations in plastic recycling rates around the world: “On the basis of limited available data, the highest recycling rates in 2014 were in Europe (30 percent) and China (25 percent), whereas in the United States, plastics recycling has remained steady at 9 percent since 2012.”
It noted that rapid increases in the pace of plastic production — half of the plastic made since 1950 was actually made in the last 13 years — will mean the potential for much more waste as global use increases.
But the study also said that recycling and incineration are on the rise globally. At current trends, it said the “global discard rate” of plastics would drop from 58 percent in 2014 to 6 percent in 2050.
It said about 18 percent of plastics were recycled in 2014, and 24 percent incinerated. That will rise to 44 percent recycling and 50 percent incineration by 2050, if current trends hold, the study said, although it noted it's very hard to predict that.
Even with those big improvements in waste management, it still said the amount of plastics landfilled or littered would double by 2050 because of large increases in the amount of plastic used.
The research said the widespread disposable use of plastic poses challenges compared to other materials.
It said that about half of plastics are used in packaging, so they enter the waste stream quickly, while most steel and concrete, the other large-scale manmade materials, are mostly used in construction and can take decades become waste.
A news release from UCSB announcing the study said the authors were “quick to caution” they aren not advocating getting ride of plastics but instead “advocate a more critical examination of plastic use.”
“What we are trying to do is to create the foundation for sustainable materials management,” Geyer said. “Put simply, you can't manage what you don't measure, and so we think policy discussions will be more informed and fact-based now that we have these numbers.”