Read the full story at Discovery News.
Before you buy something that’s biodegradable, take a look at how your community deals with trash.THE GIST
- Buying biodegradable products can ease your conscience, but they don’t necessarily do much for the Earth.
- Biodegradable products can do more harm than good for the environment if they end up in landfills.
- One of the best ways to reduce your impact on the Earth is to use less and throw less away.
Full citation for the research article: James W. Levis and Morton A. Barlaz (2011). “Is Biodegradability a Desirable Attribute for Discarded Solid Waste? Perspectives from a National Landfill Greenhouse Gas Inventory Model.” Environmental Science & Technology 45 (13), 5470–5476.DOI: 10.1021/es200721s
Abstract: There is increasing interest in the use of biodegradable materials because they are believed to be “greener”. In a landfill, these materials degrade anaerobically to form methane and carbon dioxide. The fraction of the methane that is collected can be utilized as an energy source and the fraction of the biogenic carbon that does not decompose is stored in the landfill. A landfill life-cycle model was developed to represent the behavior of MSW components and new materials disposed in a landfill representative of the U.S. average with respect to gas collection and utilization over a range of environmental conditions (i.e., arid, moderate wet, and bioreactor). The behavior of materials that biodegrade at relatively fast (food waste), medium (biodegradable polymer) and slow (newsprint and office paper) rates was studied. Poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (PHBO) was selected as illustrative for an emerging biodegradable polymer. Global warming potentials (GWP) of 26, 720, −1000, 990, and 1300 kg CO2e wet Mg–1 were estimated for MSW, food waste, newsprint, office paper, and PHBO, respectively in a national average landfill. In a state-of-the-art landfill with gas collection and electricity generation, GWP’s of −250, 330, −1400, −96, and −420 kg CO2e wet Mg–1 were estimated for MSW, food waste, newsprint, office paper and PHBO, respectively. Additional simulations showed that for a hypothetical material, a slower biodegradation rate and a lower extent of biodegradation improve the environmental performance of a material in a landfill representative of national average conditions.