We’ve all heard about the great Pacific garbage patch and other huge swirls of plastic trash floating around in our world’s oceans damaging marine ecosystems and sea creatures. But what’s not been clear is just how much more plastic is making its way from land to sea every year. Now we have an estimate.
A new study in the February 13 issue of the journal Science calculates that about 8 million tons of plastic waste wound up in the world’s oceans in 2010 — equal to five grocery bags filled with plastic for every foot of coastline in the world.
Photo by Cesar Harada
The study, by researchers at the University of Georgia in Athens, GA, and their colleagues from other schools in the US and Australia, also identifies the major sources of this plastic debris and lists the 20 countries — including China, India, Brazil and the United States — that are the biggest polluters.
It warns that the trash could increase more than tenfold in the next decade unless the international community improves its waste management practices.
The researchers combined data on solid waste from 192 different coastal countries with factors such as population density and economic status. They found that “uncaptured waste” — trash that is littered or lost from waste management systems — was the biggest source of ocean-bound plastic debris in the world.
They estimate that coastal countries generated nearly 275 million tons of plastic waste in 2010 — and that 4.8 to 12.7 million tons of that plastic made its way to the oceans. “Our estimate of plastic waste entering the ocean is one to three orders of magnitude greater than the reported mass of floating plastic debris in high-concentration ocean gyres and also globally,” they write in their report. And the trash pile is only going to get bigger: The estimate for 2015 is 9.1 million metric tons.
Using population growth data to project the increase in mass to 2025, the researchers estimate that by 2025, the volume of ocean trash would expand to 155 million metric tons. “In 2025, the annual input would be about twice the 2010 input, or 10 bags full of plastic per foot of coastline,” Jenna Jambeck, one of the lead researchers said in a statement.
“Our mismanaged waste is a function of both inadequate management — open dumping, for example — and litter,” Jambeck said. “This mismanaged waste goes uncaptured, meaning that it then becomes available to enter marine environments.”
China tops the list, having sent an estimated 1.32 to 3.53 MMT of plastic trash into the sea, Indonesia comes a distant second at 0.48 to 1.29 MMT, followed by The Philippines, Vietnam, and Sri Lanka. India is twelfth on the list, Brazil is at 16, and for a change, the US is at 20.
Infographic courtsey of Science
The researchers explain why so many Asian countries are on the list: The total annual waste generated by each country is mostly a function of its population size, with the top waste-producing countries having some of the largest coastal populations. Also, the largest contributors of plastic waste had the highest percentage of mismanaged waste.
“Sixteen of the top 20 producers are middle-income countries, where fast economic growth is probably occurring but waste management infrastructure is lacking,” the study notes. “Only two of the top 20 countries have mismanaged fractions <15%; here, even a relatively low mismanaged rate results in a large mass of mismanaged plastic waste because of large coastal populations and, especially in the United States, high per capita waste generation.”
In other words, US citizens actually create more plastic trash than their counterparts in middle-income countries, it’s just that the trash is managed a little better.
To stem the rising flow of plastic trash entering our ocean over the next decade, Jambeck and her colleagues suggest that nations around the world need to reduce their overall waste and adopt better management strategies. “We need to make sure that we are collecting and capturing solid waste and plastic around the world,” she said. “Solutions will require a combination of local and global efforts. They need to be culturally appropriate and sensitive to social and economic concerns. But a shift in how we manage waste could provide jobs and opportunities for economic innovation — and it could improve the living conditions and health of millions of people.