Health & Environmental Research Online (HERO)


Print Feedback Export to File
1998424 
Journal Article 
Methane and the greenhouse-gas footprint of natural gas from shale formations 
Howarth, RW; Santoro, R; Ingraffea, A 
2011 
Yes 
Climatic Change
ISSN: 0165-0009
EISSN: 1573-1480 
106 
4 
679-690 
WOS:000290449200010 
has summary 2225784 Assessment of the greenhouse gas footprint of natural gas from shale formations obtained by high-volume, slick-water hydraulic fracturing - Revised January 26, 2011
We evaluate the greenhouse gas footprint of natural gas obtained by high-volume hydraulic fracturing from shale formations, focusing on methane emissions. Natural gas is composed largely of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere in venting and leaks over the life-time of a well. These methane emissions are at least 30% more than and perhaps more than twice as great as those from conventional gas. The higher emissions from shale gas occur at the time wells are hydraulically fractured—as methane escapes from flow-back return fluids—and during drill out following the fracturing. Methane is a powerful greenhouse gas, with a global warming potential that is far greater than that of carbon dioxide, particularly over the time horizon of the first few decades following emission. Methane contributes substantially to the greenhouse gas footprint of shale gas on shorter time scales, dominating it on a 20-year time horizon. The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20 years. Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years. 
Methane; Greenhouse gases; Global warming; Natural gas; Shale gas; Unconventional gas; Fugitive emissions; Lifecycle analysis; LCA; Bridge fuel; Transitional fuel; Global warming potential; GWP