Alternatives to traditional PET bottles are slowly being developed, though on a small scale. Carlsberg, the Danish beer brewer, says it has spent five years developing a paper bottle lined with bioplastic. The spirit maker Johnnie Walker says that next year it will release a plastic-free paper bottle for a limited-edition run of its whiskey.

And a leading Dutch sustainable chemistry company, Avantium, working with Coca-Cola, just announced the development of a 100-percent plant-based bottle made of PEF — polyethylene furanoate, which is produced from sugars. Avantium says its bottle is better than PET as a container for soda and other products and breaks down completely in a year in a composting facility, and in a few years in the natural environment. “It really is the next-generation material that people have been looking for,” Tom van Aken, CEO of Avantium told an industry magazine.

But some skeptics say Avantium needs to publish the specifics of its claim before its technology can be considered a viable solution. And even if this plastic technology proves to be as beneficial as the company claims, the company would need to scale up production to replace PET, which would take years.

Such developments so far represent small steps compared to the growth in demand for plastic containers, especially in the developing world, which uses billions of bottles every year. Recycling traditional plastic bottles is a huge challenge for low- and moderate-income countries, many of which have virtually no recycling systems in place. As much as 95 percent of the plastic that is transported by rivers into the world’s oceans comes from 10 rivers in Asia and Africa.

Inertia is also a factor. The massive global packaging system is still geared to use new plastic made from cheap oil, not recycled plastic, which is much more expensive. “As long as we continue to produce virgin resin, recycling will never happen,” said Michigan State’s Narayan. “Brand owners — Coca-Cola and Pepsi — need to say they will not sell water or juice in a bottle that does not contain recycled content, irrespective of the cost. The pop bottle of the future will still be the current PET bottle. It does a great job. But we need the ability to collect it and recycle it and recycle it. That is the future.”