Submitted to: Journal of Waste Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/22/2006
Publication Date: 2/1/2007
Citation: Spokas, K.A. 2007. Methane: Signs of progress along the road [Editorial]. Waste Management. 27(4):459-460. Interpretive Summary: The slow down of the growth of the concentration in atmospheric methane is the result of several measures that have been taken over the last decades. This editorial discusses the growth of the landfill gas utilization and recovery projects world-wide although the exact contribution that these landfill gas utilization projects have had is difficult to directly measure. The end result of the slow down in the growth of atmospheric methane does indicate that there has been a reduction in the amount of methane released to the atmosphere. The growth of landfill gas recovery projects has reduced the contribution of landfill methane to the atmosphere.
Technical Abstract: Recent findings of Simpson et al. (Geophysical Research Letters, 33:L22808, doi:10.1029/2006GL027330, 2006) have indicated that the growth in the concentration of atmospheric methane has leveled off based on air sampling conducted throughout the Pacific basin (71 deg N to 47 deg S) over the last seven years. This slow down is in stark contrast to the increasing atmospheric methane concentrations during the 80’s and 90’s. This is positive news in terms of human interaction in reducing greenhouse gas emissions. One aspect of the reduced burden of methane in the atmosphere comes from the increasing number of landfill gas recovery and utilization projects. There has been exceptional growth in the number of landfill gas utilization projects worldwide, with the number of active projects over 1100 with several additional projects planned. In addition to the new projects, there is rarely a landfill built currently without active landfill gas recovery which is subsequently utilized or flared. In developed countries, the decision to install a gas recovery system is largely controlled by regulations. In developing countries, it is primarily a financial decision. This financial hurdle has been reduced recently making it easier to establish viable projects in developing countries through greenhouse gas emission credit trading. This response of the industry to reducing methane emissions from landfills is worthy of notice.