What will it take to solve the planet’s plastic pollution crisis?

The world currently produces more than 50 million tons of “mismanaged” plastic waste each year, and some researchers expect this flood of plastic pollution to double by the middle of this century. If global plastics treaty negotiations get underway this week, that number could be reduced by 90%.

Plastic pollution clogs land and ocean ecosystems. “This affects all levels of the food chain, from phytoplankton cells to humans,” he says. Sarah Jeanne Royer at the University of California, San Diego. Plastics are also responsible for about 5% of greenhouse gas emissions.

That’s why most countries around the world are meeting in Busan, South Korea this week to discuss the final details of a global treaty aimed at ending plastic pollution. Already in 175 countries by 2022 agreed to adopt a legally binding treaty. And over the past two years, there has been debate over exactly what should be required, particularly disagreements over setting limits on the production of new plastics.

To increase clarity of argument, Douglas McCauley University of California, Santa Barbara, and his colleagues used an artificial intelligence model trained on economic data to test how policies under consideration would affect global plastic pollution. “I wasn’t so sure. [eliminating plastic pollution] It was actually possible,” says McCauley. “But it turns out you can get pretty close.”

According to their projections, under current conditions, plastic pollution is expected to roughly double to 100-139 million tons by 2050. However, combinations of all four policies are still being discussed. Current Treaty DraftThis was enough to reduce this by over 90%.

The most impactful of these is mandating that plastic products contain at least 40% recycled content. That rule alone cut plastic pollution in half by the mid-20th century. McCauley said the reason this effect is so important is because it reduces demand for newly made or “first-time” plastics while also driving demand for recycled materials. “Suddenly there was a huge global market for recycling.”

But recycling alone wasn’t enough. “If the goal is to end plastic pollution, we need to take action across its entire life cycle,” he says. Deeper cuts required net plastic production to be limited to 2020 levels. According to the model, this production limit would reduce plastic pollution by about 60 million tons per year by mid-century. These changes also had the greatest impact on greenhouse gas emissions from plastic production. That’s because extracting fossil fuels and converting them into new plastics involves an emissions-intensive process.

A third policy, spending $50 billion on waste management, reduced pollution by about the same amount as the production cap. This is especially true if these funds are spent in low-income countries with poor infrastructure that are most inundated with plastic pollution. “When you start talking about global finance, [the amount of money needed] It’s not that big,” McCauley says. “Building a sanitary landfill is different from building a port.”

Finally, a small tax on plastic packaging could reduce pollution by tens of millions of tons. The researchers based their estimates on case studies of how people reduced their plastic use in response to similar taxes: 5 cent fee Disposable plastic bags in Washington DC. The money raised from these taxes could also be used to pay for other changes, such as building waste management infrastructure or improving recycling systems.

Royer, who was not involved in the study, said he thinks both of these policies would be helpful. Reducing the use of single-use plastics, such as grocery bags and plastic forks, through taxes or bans could also make a difference, she says. “If you look at plastic pollution in general, 40% of the plastic produced is single-use.”

But she points out that local rules alone will never solve the problem. For example, California banned some single-use plastic bags a decade ago and banned all such bags this year. But most of the plastic pollution that washes up on beaches comes from outside the state. Plastic waste in California is typically flotsam that drifts across the Pacific from Asia or remains from fishing operations. “There are no borders,” says Royer.

This is where global treaties come into play. The researchers showed how implementing a variety of policies across the world could reduce three things: the amount of mismanaged plastic waste, the production of new plastics, and plastic-related greenhouse gas emissions. Combining the four key policies shown in the graph below, all three measures reduced mismanaged waste by 91%.

In Busan, the countries have now reached a deadline to decide on a final draft treaty, but remain deeply divided on key issues. The main sticking point is whether the treaty should include production limits on newly created plastics, which the researchers said would be the second most impactful policy. Plastic producing countries and the petrochemical industry oppose production limits and instead support recycling measures.

A ‘largely ambitious coalition’ of 68 countries, including the UK, is pushing for a treaty that would include both, with the goal of eliminating plastic pollution by 2040. etc Researchers also claimed Ending pollution requires limits on plastic production. But just last week, advocates of production limits were disappointed to learn that: report The United States will not support specific limits on plastic production. McCauley recently sent an open letter to the Biden administration signed by more than 100 researchers. Support a strong plastics treaty.

“We are at a critical moment,” he said. Erin Simon The World Wildlife Foundation, an environmental advocacy group, sends an email to the media. “Our last golden opportunity to reach an agreement that will stop plastic from entering nature is at hand. But this will only happen if countries come to the negotiating table with a clear vision and determination to get the job done.”