Man's legacy on Earth may be the piles of plastics we've mass produced—roughly 8.3 billion metric tons so far, according to a new study published today in Science Advances.
In the first ever global analysis of plastic production, researchers from universities across the United States combined production data with product lifetime information from various industries—such as construction, packaging, and consumer goods—to find out how much plastic humans have made, and how much of it is still around.
"You can't manage what you don't measure," says Roland Geyer, an associate professor at the University of California–Santa Barbara and lead author on the new study. "I think in order to manage plastics sustainably hopefully and stem the tide of plastics we need to know how much we're making and where it goes."
About 30 percent of all plastics made since the middle of the 20th century are still in use, but the vast majority of plastic waste, it turns out, is still around as well. Just 12 percent has been incinerated—a process that presents its own environmental and public-health perils—and only 9 percent was recycled.
"Between 2002 and 2015 we made the exact same amount of plastic that we made between 1950 and 2002."
There were vast regional differences in recycling, however: The recycling rate in the U.S. was 9 percent, compared to 30 percent in Europe, and 25 percent in China. Since none of the most commonly used plastics are biodegradable, nearly 80 percent of the more than six billion metric tons of plastic waste generated between the 1950s (when the large-scale production of synthetic plastics really took off) and 2015 is accumulating in our landfills, ocean basins, far-flung islands, and other natural environments.
The fact that, over time, a plastic item will really only break down into smaller and smaller fragments is only part of the problem. The amount of plastics made every year continues to climb. "Between 2002 and 2015 we made the exact same amount of plastic that we made between 1950 and 2002," Geyer says. "That's rather stunning."
If the current trends in production, incineration, and recycling continue, there will be 12 billion metric tons of plastic waste littering the globe by 2050. It's clear we need a better management strategy. "We think that to successfully address the plastic waste challenge that we face, we need everything that we have in our tool box, from recycling to energy recovery to use reduction," Geyer says. "It shouldn't be left to the consumer alone."
But this work has forced Geyer to re-evaluate his own use of plastics and look for ways to consume less. "It made me terribly aware of how much plastics I use," he says. "It's humbling to see how difficult it is to walk the walk when it comes to using plastics."