It’s woven into clothing, spilling out of recycling bins, and floating in massive patches across the ocean. Plastic is everywhere—and now a global analysis of mass-produced plastic reveals that of the 8.3 billion metric tons of plastic created by 2015, 6.3 billion are already out of use. What’s more, most of it is in landfills and nature.
Mass production of plastic began around 1950, and has since exceeded almost all other man-made materials. It hasn’t surpassed cement and steel, but the study’s authors point out that those materials are largely used in construction, providing decades of use. Plastics, on the other hand, mostly go toward short-term use.
“Half of all plastics become waste after four or fewer years of use,” said Roland Geyer, associate professor of industrial ecology at the University of California, Santa Barbara, and lead author of the paper. The study, which was published in the journal Science Advances, looked at production, use, and lifetime data of polymer resins, synthetic fibers, and additives across eight industrial sectors.
While plastics used in industrial machinery or construction regularly have lifespans exceeding 20 or 30 years, respectively, the largest market for plastic is packaging. And most plastic packaging is discarded in the same year it’s produced.
Of the total plastic discarded by 2015, the researchers determined that 79% went into landfills or the natural environment, 12% was incinerated, and 9% was recycled. Recycling, they point out, only delays final disposal, and it’s unclear whether recycling actually prevents new plastic from being produced.
“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.”
At the current rate, the researchers project that total plastic production will reach 34 billion metric tons by 2050, with total plastic waste reaching 12 billion metric tons. Mass-produced plastics do not biodegrade “in any meaningful way,” the authors note, pointing out that sunlight weakens plastic and causes it to break into tiny fragments known as microplastics. These fragments plague oceans and freshwater ecosystems alike—the same group of researchers estimated in a previous study that 8 million metric tons of plastic entered the ocean in 2010 alone.
Increased research and media attention has led to some efforts to address the issue of plastics in water, and this month marks the beginning of a U.S. ban on plastic microbeads commonly used in personal care products. But little is known about how plastics affect terrestrial ecosystems.