Findings, published in the journal Communications Earth & Environment, come as nations prepare to battle again over a treaty to address plastic pollution after the last round of negotiations failed to broker an agreement.
Plastic has been found in the depths of the remotest oceans and in snow atop the highest mountains, and tiny particles have been detected in blood and breast milk.
Yet despite growing international concern, there has been “a notable lack of comprehensive analysis of plastics along their supply chain,” wrote Quanyin Tan and colleagues.
They found that just 9.5% of the 400 million tonnes of new plastic in 2022 was produced from recycled materials.
“The global recycling rate remained stagnant… reflecting little improvement from previous years,” wrote the authors.
The rest was produced from fossil fuels, predominantly oil and gas, demonstrating “little progress” in addressing environmental concerns related to plastics production.
Contamination with food and labels made some plastics more difficult to recycle, while the diversity and complexity of additives in materials posed another obstacle.
But another hindrance is purely economic: it is often cheaper to make new or “virgin” plastic than it is to recycle it.
They identified the United States, the largest consumer of plastic per capita, as having one of the lowest recycling rates with just 5% reused.
They also noted a “significant shift” in global waste disposal, with landfill in decline and around one-third of plastic waste being incinerated.
But burning was “emerging as the most practiced method for managing plastic waste” with the European Union, China and Japan having among the highest incineration rates.