This holiday season, the popularity of online shopping collides with upheaval in cardboard recycling. China’s 2017 decision to turn away America’s trash has left the recycling industry reeling as it figures out what to do with all the packaging online shoppers leave behind.

Some municipal recycling programs have closed. Even the ones that haven’t still have headaches: specifically, filthy recyclables. All of that leads to more cardboard in landfills.

“the Amazon effect”

The rise in curbside cardboard waste coming from packaging is “the Amazon effect,” says David Biderman, the executive director of the Solid Waste Association of North America, an industry group. It peaks around the holidays — particularly as online shopping has only gotten more popular. Last year, Cyber Monday was the biggest shopping day for Amazon in the history of the company. The trend extends beyond the holidays: US Postal Service deliveries have doubled to 6.2 billion in 2018, from 3.1 billion in 2009.

As Americans have gotten more enthusiastic about online shopping, China — which once welcomed almost half the world’s recyclables — has gotten more stringent about what it will accept. Starting in January 2018, China stopped accepting shipments of cardboard that are contaminated with more than 0.5 percent of other materials.

“It’s very difficult for American material recovery facilities to satisfy that standard because Americans put plastic bags and chewing gum and bowling balls and dirty diapers and everything else you can imagine into the recycling containers,” Biderman says. The strict rules also apply to plastic and other recyclables, but cardboard and mixed paper have seen the sharpest drops in prices.

All those packages, along with the stricter rules on recycling, mean more cardboard in the trash—especially during the holiday shopping season. Republic Services, a US waste hauler that operates in 42 states, expects each household to dispose of 25 percent more trash, or about 1,000 extra pounds, between Thanksgiving and New Year’s Day. But thanks to China’s new policies, there will be less money to be made recycling. “To use the word bluntly: that’s a crisis, an economic crisis in the viability of recycling in the US,” Richard Coupland, vice president of municipal sales at Republic Services, tells The Verge.

“To use the word bluntly: that’s a crisis”

Amazon says that it has eliminated more than 1.18 billion shipping boxes since 2008 through its sustainable packaging initiatives. It’s even threatened to fine third-party sellers for not reducing packaging waste. But Amazon’s strict standards have inadvertently led to a boom of repackaging centers that unbox and re-box goods to make them fit to ship — leaving behind even more garbage.

Republic Services has seen about a 5 percent increase in the overall volume of cardboard it has picked up and resold for recycling over roughly the past seven years. But some locations have seen more dramatic increases. Sims Municipal Recycling, which takes in much of New York City’s recovered cardboard at one of the largest recycling facilities in North America, tells The Verge that corrugated cardboard — the kind boxes are made of — is almost half of the curbside recycling stream today. It was just 15 percent of curbside recycling 15 years ago.

There has also been a noticeable shift in the source of the cardboard, says Coupland: it’s coming from peoples’ homes instead of brick-and-mortar businesses. That’s bad news, since retailers are less likely to generate cardboard that’s too filthy to be recycled. Consumers’ cardboard boxes are often mixed with other, dirty recyclables like ketchup bottles or soda cans that spill their contents over the cardboard. On average, about 25 to 30 percent of the materials picked up by a recycling truck are too contaminated to go anywhere but a landfill or incinerator, Coupland says.

Cities are scrambling

So the quality of cardboard being recycled today isn’t what it used to be, and it’s not nearly as valuable as it once was, thanks to China’s more stringent demands on cleanliness. Cities across the US are still scrambling to figure out where to send all their cardboard and plastics. There aren’t enough domestic paper mills yet to meet the demand, and the glut of recovered materials has led to a dramatic drop in the value of cardboard.

Biderman estimates that there’s been a more than 50 percent decline in the price of recovered cardboard in the US since China’s decision. Coupland believes there’s actually been as much as an 80 to 100 percent devaluation in some markets. That’s a big reason why cities across the country are scaling back or completely dumping their recycling programs.

Recycling cardboard helps cut greenhouse gas emissions, too. Corrugated cardboard can be recycled into more of the same material seven times. After that, it can be turned into paperboard used in things like cereal containers. Without recycled cardboard, more trees need to be cut down, hauled to lumber yards, and pulped, which also means more emissions. “I think we need to be looking at it through that lens,” Biderman says.