The world’s oceans are facing a vast wave of plastic waste over the next 20 years, as growing populations and billions of dollars of investment in petrochemicals outstrip efforts to ban and reduce everything from plastic bags to disposable cups, according to a study by a team of U.K.-based researchers.

The researchers found that at current “business as usual” rates, the scale of plastic entering the world’s oceans will triple by 2040, to an average of 29 million metric tons of waste, per year—equivalent to 50 kilograms, or 110 pounds, of waste per meter of coastline, globally. If all measures promised by governments are implemented, plastic waste will be reduced by only 7% compared with levels of waste if no efforts had been taken at all, the report said.

As a result, current efforts to reduce plastic waste are wildly insufficient, the researchers concluded. Truly reducing waste will require using every available solution, from recycling to designing replacement products, including—perhaps most important—a focus on new plastic not being produced at all.

The paper, Evaluating Scenarios Toward Zero Plastic Pollution, was published in the journal Science on July 23 with an accompanying report, as a collaboration from the University of Oxford, the University of Leeds, the Ellen MacArthur Foundation, and Common Seas.

“The collective impact of all current national and municipal legislation regarding items such as straws, bags, stirrers, cups, cotton swabs, and bottles simply does not add up to a significant reduction in the overall quantity of plastic waste generated and leaked globally,” the accompanying report said.

It continued: “To compound this shortfall, there has been insufficient growth in waste collection infrastructure over the past two decades relative to plastic waste generation, which we estimate has been growing at a 4% to 7% compound annual growth rate.”

Meanwhile, corporate commitments to reduce plastic waste are in fact still relatively niche and small scale, the report adds.

The researchers estimated that plastic waste can be reduced by 80% with existing technology—but to be successful, such an effort cannot stop at simply improving recycling or reducing plastic use, but must include how a product is designed, and how it is replaced and reused, using all potential methods together.

That includes focusing on mechanical recycling—rather than chemical recycling, which can be emissions heavy—and making items reusable, rather than simply replacing plastic with other materials, which can have knock-on environmental and social impacts.

But focusing on reducing the creation of plastic in the first place is the most attractive solution from an environmental, economic, and social perspective, the researchers said: “It offers the biggest reduction in plastic pollution, often represents a net savings, and provides the highest mitigation opportunity in GHG [greenhouse gas] emissions.”

A widespread approach to reducing plastic waste would ultimately cost governments roughly $600 billion by 2040—$7 billion less than it would cost governments to continue to manage the knock-on impacts of plastic waste under the current system, the researchers argued.

The technical and logistical difficulties of recycling—just one element of the waste cycle of plastic—are already challenging.

Even in the world’s most diligent recycling nations, like Germany, single-use plastics—though collected by local authorities—usually end up in landfills, because they are too difficult or uneconomical to process. Meanwhile, local collection in municipalities in the U.S., if recycling is collected at all, long relied on sending that plastic to be processed in China—a system one local authority equated to “recycling on life support.” Since China stopped accepting waste, an even larger logistical challenge has been created.

But report which published on July 23 also refers to an awkward contradiction in the global economy: Even as governments and companies pledge to reduce their use of straws or plastic bags, cheap oil and gas prices have made “virgin,” or newly created, plastic far more economical than recycling, which is frequently expensive and labor intense, as Vivienne Walt noted in Fortune’s business and climate change issue earlier this year. Meanwhile, growing populations have made petrochemicals a growth area for many of the world’s largest oil and gas companies, resulting in billions of dollars of investment in expanding capacity.

That conundrum has arguably only been highlighted by the pandemic, as delivery food orders and disposable hygiene products, from masks to gloves to wipes, have made a comeback—and oil prices have sunk further.

The ecological consequences of not addressing plastic waste are already being felt. In only the latest example, a study published on July 22 from researchers at the University of Exeter in the journal Scientific Reports examined the stomachs and guts of a group of sharks caught as bycatch in the waters off the coast of Cornwall, in southeast England. Researchers found that nearly 70% had ingested not only microplastics, but materials from disposable hygiene items—like face masks.