A Billion More Tons of Plastic Could Blanket Earth by 2040

Imagine your favorite stretch of coastline—white-sand beaches, rocky tide pools, the White Cliffs of Dover, what have you. Now transport yourself ahead two decades, after plastic production and waste have continued to skyrocket. Humanity is now unloading 29 million metric tons of bottles, bags, and microplastics (little bits smaller than 5 millimeters) into the oceans annually. That means for every meter of your favorite coastline, 50 kilograms—that’s 110 pounds—of plastic is entering the sea every year.
“Now imagine that's happening for every meter of coastline around the world,” says Richard Bailey, who studies environmental systems at Oxford University. “That's the amount that we're looking at—it's a colossal amount.”Over the last few years, scientists have been exposing the hazards of microplastics , or ground-up particles that easily blow around the world and work their way into plants and animals . But all the while, macroplastics like bottles have been accumulating in the environment, shedding microplastics as they degrade. Writing today in the journal Science, Bailey and his colleagues are publishing the alarming findings of their comprehensive review of the cycle of all this plastic. If we as a species don’t collectively take action, they warn, 1.3 billion metric tons of plastic will flow into the sea and tumble across the land between the years 2016 and 2040. Even with immediate and drastic action, that figure could be 710 million metric tons: 460 million of them on land and 250 million in the water. Making matters worse, throughout much of the world people burn the plastic they can’t easily recycle, to the tune of perhaps 133 million metric tons of waste by 2040. That spews dangerous toxins and CO2 (plastic is made of oil, after all), further warming the planet.
To model the plastic waste ecosystem, the researchers created eight “geographic archetypes,” instead of picking apart the dynamics of how individual countries handle trash. “We didn't want it to become a blame game,” says the study’s co-lead author, Winnie Lau, senior manager of the Pew Charitable Trusts’ project on ocean plastic pollution. “What we wanted to do was to understand the problem and how it came about, rather than pointing out specific countries.”

Lau and her colleagues named these eight archetypes after national income levels and geographical designations, so high-income urban and low-income urban, or high-income rural and low-income rural. Each is expected to have a different level of waste management services. “The higher the density, the easier it is for core services to be provided,” says Lau. “Obviously, high-income places have more services they can provide, and low-income places don't have as much resources to pay for services like waste management.”

So a low-income rural area is more likely to struggle with proper disposal of plastic waste than a high-income area. That’s especially true for an island nation without the room to bury what residents don’t recycle. The temptation, then, is to burn the stuff that’s not recyclable. For the plastic that is reusable, informal waste pickers might go door to door collecting in the absence of an official waste management program. By contrast, a high-income urban geographic archetype might have a robust waste management infrastructure.

The team then created a mathematical model that could predict how much plastic waste these archetypes would produce by 2040. “The job of the model was to integrate the data that we could collect for all of the different geographical archetypes around the world,” says Bailey. “We tried to work out how the plastic flowed around the system in each of those types. And then we just basically crank the handle and we push the plastic through the system and see where it ends up.”