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Re: [greenyes] Relationship of Global Warming to Recycling
    Included in that litany is the inability to prevent the contemporaneous release of most of the gases generated in landfills, 46%-50% of which is methane, a greenhouse gas more than 21 times as virulent as CO2. Although hard data does not exist, based upon what is known, almost certainly less than 25%, and probably less than 20% of the lifetime emissions are actually captured.  The vast majority of methane emitted from in landfills, which does not exist in the garbage we discard, but instead is generated in significant quantities only in the anaerobic (or oxygen starved) conditions of large lined landfills, adds substantially to mankind's climate-changing gases, very likely in the U.S. greater than 10% of the total.

To put things a bit more into perspective.  Assuming the science employed was "good" according to the The Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2002 published by the US EPA in April of 2004 waste activities as a portion of all US GHG emissions represented 3.4% (237.2 Terragrams of Carbon Dioxide Equivalent) in 2002.  The term "waste" includes landfills, wastewater treatment, and human sewage.  That 3.4% includes methane and nitrogen oxide and relatively insignificant amounts of other GHG.  Nitrogen oxide (a hugely more "virulent" GHG than methane) is associated with human sewage while methane is associated with landfills and wastewater treatment. 

The EPA estimates that LFG recovery systems have an efficiency of 75%.  It also estimates that 49% of all landfill methane was generated at landfills with recovery systems, and the remaining 51% was generated at landfills without LFG recovery.  Additionally, of the 49% of all methane generated at landfills with LFG recovery, 49% (or 24% percent of all methane) was generated at landfills that use LFG to generate electricity, and 51% (or 25% of all methane) at landfills that flare LFG (flaring removes the virulency).  See EPA 2002. EPA530-R-02-006 - Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks.

All in all the contribution of landfilling US style to US GHG emissions would seem to be arguably insignificant relative to the amount of carbon dioxide being pumped skyward from power plants, automobiles, volcanic eruptions, forest fires, etc. even more so when you consider the portion of methane currently being collected in landfill gas operations.

Respectively Yours,


Peter Anderson
4513 Vernon Blvd. Suite 15
Madison, WI 53705
(608) 231-1100 / Fax 233-0011
Stephan Pollard
Environmental Dynamics Doctoral Program
University of Arkansas
Rm 113 Ozark Hall
Fayetteville, AR 72701
Tel: (479) 575-6603

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