This is Scientific American's 60-second Science, I'm Steve Mirsky.So you buy something made of plastic and it's labeled biodegradable.You can rest easy knowing that after you throw it out it will harmlessly break down. Well, not so fast."When we look at biodegradability as it pertains to landfills, biodegradability is not a desirable attribute for a material.And the reason for this is that when we design for biodegradability, we're typically designing for rapid biodegradability,and yet landfills do not begin to collect the gas that's produced typically for two years...so much of the gas, the methane, from biodegradability is released to the environment before gas collection systems are installed."Morton Barlaz. He heads the Department of Civil, Construction and Environmental Engineering at North Carolina State University.And he spoke June 6th on Capitol Hill at the third "Science on the Hill" event,co-hosted by Scientific American and California Congressman Jerry McNerney.The theme of this session: "Solving the Plastic Waste Problem.""Now I just answered the question from a landfill perspective.If I were to switch hats and say, well, is it desirable from a litter perspective, sure.If it actually biodegrades and is converted to gas, then the litter would disappear, and that's desirable.