A study published today in the journal Science Advances has revealed that the United States is the No. 1 generator of plastic pollution in the world and as high as the No. 3 generator of ocean plastic waste when taking into account its scrap plastic exports as well as the latest figures on illegal dumping and littering in the country. While previous studies had suggested that Asian countries were responsible for the bulk of ocean plastics, the new study upends this assumption by taking into account the plastic that the U.S. ships abroad.

China may be the world’s largest manufacturer of plastic, the report finds, but the United States is by far the world’s largest generator of plastic waste—it produced about 42 million metric tons of the stuff (46 million U.S. tons) in 2016. The U.S. also ranks as high as third among coastal nations for contributing litter, illegally dumped trash and other mismanaged waste to its shorelines. Using plastic waste generation data from 2016 – the latest available global numbers – scientists from Sea Education Association, DSM Environmental Services, University of Georgia, and Ocean Conservancy calculated that more than half of all plastics collected for recycling (1.99 million metric tons of 3.91 million metric tons collected) in the United States were shipped abroad. Of this, 88% of exports went to countries struggling to effectively manage, recycle, or dispose of plastics; and between 15-25% was low-value or contaminated, meaning it was effectively unrecyclable. Taking these factors into account, the researchers estimated that up to 1 million metric tons of U.S.-generated plastic waste ended up polluting the environment beyond its own borders.

“For years, so much of the plastic we have put into the blue bin has been exported for recycling to countries that struggle to manage their own waste, let alone the vast amounts delivered from the United States,” lead author and Sea Education Association professor of oceanography Dr Kara Lavender Law said in a press release. “And when you consider how much of our plastic waste isn’t actually recyclable because it is low-value, contaminated or difficult to process, it’s not surprising that a lot of it ends up polluting the environment.”

The landmark 2015 agreement was designed to limit the global warming causing the climate crisis to well below two degrees Celsius above pre-industrial levels, and ideally to limit it to 1.5 degrees Celsius. The U.S. is currently responsible for around 15 per cent of greenhouse gas emissions, but it is historically the country that has contributed the most emissions to the atmosphere, NPR pointed out. Under the Paris agreement, the U.S. had pledged to reduce emissions around 25 per cent by 2025 compared to 2005 levels, but it is now only on track to reduce them by 17 per cent.

The new analysis concluded that the U.S. generated around 42 million metric tons of plastic in 2016. Of the U.S. plastic collected for recycling, more than half of it was shipped abroad, and 88 per cent of that was to countries that struggle to adequately recycle. Further, 15 to 25 per cent of it was contaminated or poor quality plastic that would be extremely difficult to recycle anyway. These figures mean that the U.S. is polluting coasts in foreign countries with as much as one million tons of plastic.

“For some time, it has been cheaper for the United States to ship its recyclables abroad rather than handle them here at home, but that has come at great cost to our environment,” said Natalie Starr, principal at DSM Environmental Services and a co-author of the study. “We need to change the math by investing in recycling technologies and collection programs, as well as accelerating research and development to improve the performance and drive down the costs of more sustainable plastics and packaging alternatives to address the current challenge.”