Most
has now been discarded
University of Georgia
Humans have created 8.3 billion metric tons of plastics since
large-scale production of the synthetic materials began in the early 1950s, and
most of it now resides in landfills or the natural environment, according to a
study published in the journal Science Advances.
Led by a team of scientists from the University of Georgia, the
University of California, Santa Barbara and Sea Education Association, the
study is the first global analysis of the production, use and fate of all
plastics ever made.
The researchers found that by 2015, humans had generated 8.3
billion metric tons of plastics, 6.3 billion tons of which had already become
waste. Of that waste total, only 9 percent was recycled, 12 percent was
incinerated and 79 percent accumulated in landfills or the natural environment.
If current trends continue, roughly 12 billion metric tons of
plastic waste will be in landfills or the natural environment by 2050. Twelve
billion metric tons is about 35,000 times as heavy as the Empire State
Building.
"Most plastics don't biodegrade in any meaningful sense, so
the plastic waste humans have generated could be with us for hundreds or even
thousands of years," said Jenna Jambeck, study co-author and associate
professor of engineering at UGA. "Our estimates underscore the need to
think critically about the materials we use and our waste management
practices."
The scientists compiled production statistics for resins, fibers
and additives from a variety of industry sources and synthesized them according
to type and consuming sector.
Global production of plastics increased from 2 million metric
tons in 1950 to over 400 million metric tons in 2015, according to the study,
outgrowing most other human-made materials. Notable exceptions are materials
that are used extensively in the construction sector, such as steel and cement.
But while steel and cement are used primarily for construction,
plastics' largest market is packaging, and most of those products are used once
and discarded.
"Roughly half of all the steel we make goes into
construction, so it will have decades of use -- plastic is the opposite,"
said Roland Geyer, lead author of the paper and associate professor in UCSB's
Bren School of Environmental Science and Management. "Half of all plastics
become waste after four or fewer years of use."
And the pace of plastic production shows no signs of slowing. Of
the total amount of plastics produced from 1950 to 2015, roughly half was
produced in just the last 13 years.
"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."
The same team of researchers led a 2015 study published in the
journal Science that calculated the magnitude of plastic waste
going into the ocean. They estimated that 8 million metric tons of plastic
entered the oceans in 2010.
"There are people alive today who remember a world without
plastics," Jambeck said. "But they have become so ubiquitous that you
can't go anywhere without finding plastic waste in our environment, including
our oceans."
The researchers are quick to caution that they do not seek the
total removal of plastic from the marketplace, but rather a more critical
examination of plastic use and its end-of-life value.
"There are areas where plastics are indispensable,
especially in products designed for durability," said paper co-author Kara
Lavender Law, a research professor at SEA. "But I think we need to take a
careful look at our expansive use of plastics and ask when the use of these
materials does or does not make sense."
