Biodegradable plastics are raising hopes for a potential solution to overstuffed landfills, climate change and diminished fossil fuel resources.
Yet they may not be as quick a fix as people would like, and researchers face an uphill climb towards finding a truly sustainable, renewable and biodegradable plastic.
Bioplastics are sourced from plant-based materials rather than petroleum, and The Guardian reports that several universities in the United States are working to develop plastics that degrade in a matter of months.
Yet conventional plastics — which linger for hundreds of years and occupy up to a quarter of available landfill space in the United States — are currently cheaper to make.
This might change with rising oil prices worldwide, but meanwhile, petroleum-based plastic waste has spread from landfills to the ocean.
According to the San Francisco Chronicle, the world’s largest garbage dump floats in the Pacific Ocean somewhere between California and Hawaii — and 80 percent of it is plastic.
The so-called Pacific Garbage Patch is twice the size of Texas and sits in a perfect storm of currents that holds it together.
The garbage patch, so massive it is unlikely ever to be cleaned up, brings long-term problems.
Instead of organically degrading, plastics slowly break down into smaller pieces that are eaten by marine animals and wreak havoc on their systems.
And that’s just the plastic that floats.
The Sydney Morning Herald quoted Greenpeace as saying 70 percent of all plastics that end up in the ocean sink to the bottom, posing additional risks to sea life.
Biodegradable plastics could help, an Ocean Conservancy spokesman told the Chronicle.
However, coming up with a durable, long-lasting bioplastic is challenging and expensive.
“It would be hard to expect a plastic product with excellent resistance against wearing, tearing and weathering during its service life to also have biodegradability after usable service life,” Dr. KB Lee, a chemical engineering professor in Missouri, told The Guardian.
Furthermore, all bioplastics are not as green as they seem.
The term “bioplastics” can refer to materials that are renewable and biodegradable, as well as to plastics that merely have some renewable materials in them, reports the International Herald Tribune.
One common type of compostable bioplastic is actually sourced from inorganic petroleum — and even the terms “biodegradable” and “compostable” aren’t necessarily what they seem.
According to The Guardian, plastic labeled as compostable won’t always break down once it’s thrown away, and often requires expensive digesters that most landfills lack.
“Just because it’s biodegradable does not mean it’s good,” Peter Skelton, who works for a government-funded waste program in the United Kingdom, told the newspaper. “In theory bioplastics are good. But in practice there are lots of barriers.”
“Old idea of using bioplastics gets a new lease of life”
The Guardian, July 10, 2008
“Bioplastics: The challenge of viability”
The International Herald Tribune, July 6, 2008
“Continent-size toxic stew of plastic trash fouling swath of Pacific Ocean”
The San Francisco Chronicle, October 19, 2007
“The plastic killing fields”
The Sydney Morning Herald, December 29, 2007
“‘Sustainable’ bio-plastic can damage the environment”
The Guardian, April 26, 2008