As tons of plastic items continue to take up space in landfills, and the floating Great Pacific Garbage Patch continues to grow, environmentally-conscious consumers are understandably becoming more interested in biodegradable alternatives to traditional plastic. Whether it's because they share these concerns, or are just trying to cash in on an "eco-fad," many companies have responded by producing biodegradable versions of formerly near-eternal plastic products. While biodegradable products are designed to reduce the amount of trash clogging up our waterways and spoiling our parks, at least one scientist believes they may ultimately be doing more harm than good.

According to Dr. Morton Barlaz, head of North Carolina State University's Department of Civil, Construction, and Environmental Engineering, the problem is methane gas.

"Biodegradable materials, such as disposable cups and utensils, are broken down in landfills by microorganisms that then produce methane," he stated. "Methane can be a valuable energy source when captured, but is a potent greenhouse gas when released into the atmosphere."

Some landfill sites capture methane produced by decomposing garbage, and store it for energy use. While this would seem to add even more value to biodegradable products, the U.S. Environmental Protection Agency states that only an estimated 35 percent of U.S. landfills actually do this. The agency estimates that another 34 percent capture the gas and burn it, with 31 percent simply allowing it to rise into the atmosphere.

Barlaz believes that the Federal Trade Commission's requirement for supposedly "biodegradable" products to biodegrade quickly is only making the problem worse. In the U.S., landfills that do collect methane aren't required to install gas collection systems for at least two years after garbage has been buried. Within that amount of time, he worries, fast-biodegrading materials could have already released most of their methane.

"If we want to maximize the environmental benefit of biodegradable products in landfills, we need to both expand methane collection at landfills and design these products to degrade more slowly," he said.

Clouding the issue is the fact that, to some extent, it pits the environmental concerns of plastic waste and climate change against one another. For those who don't think that man-made greenhouse gases pose a serious threat to the environment, the methane-producing biodegradable garbage would likely seem to be the lesser of two evils. In any case, it's probably safe to say that no one should view biodegradable products as an excuse to not reduce, reuse or recycle.

Dr. Barlaz's paper "Is Biodegradability a Desirable Attribute for Discarded Solid Waste? Perspectives from a National Landfill Greenhouse Gas Inventory Model" was published this week in the journal Environmental Science & Technology. The research was supported by Procter & Gamble and the Environmental Research and Education Foundation.