Both social and engineering factors must be further explored and scrutinized across the globe—as should notions of justice related to flooding impacts and responses.
Image courtesy of Shutterstock.com/Ekaterina Pokrovsky.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited* by Barbara J. Finlayson-Pitts, University of California, Irvine, Irvine, CA, and approved March 12, 2014 (received for review September 4, 2013)
Significance
We identified a significant regional flux of methane over a large area of shale gas wells in southwestern Pennsylvania in the Marcellus formation and further identified several pads with high methane emissions. These shale gas pads were identified as in the drilling process, a preproduction stage not previously associated with high methane emissions. This work emphasizes the need for top-down identification and component level and event driven measurements of methane leaks to properly inventory the combined methane emissions of natural gas extraction and combustion to better define the impacts of our nation’s increasing reliance on natural gas to meet our energy needs.
Abstract
The identification and quantification of methane emissions from natural gas production has become increasingly important owing to the increase in the natural gas component of the energy sector. An instrumented aircraft platform was used to identify large sources of methane and quantify emission rates in southwestern PA in June 2012. A large regional flux, 2.0–14 g CH4 s−1 km−2, was quantified for a ∼2,800-km2 area, which did not differ statistically from a bottom-up inventory, 2.3–4.6 g CH4 s−1 km−2. Large emissions averaging 34 g CH4/s per well were observed from seven well pads determined to be in the drilling phase, 2 to 3 orders of magnitude greater than US Environmental Protection Agency estimates for this operational phase. The emissions from these well pads, representing ∼1% of the total number of wells, account for 4–30% of the observed regional flux. More work is needed to determine all of the sources of methane emissions from natural gas production, to ascertain why these emissions occur and to evaluate their climate and atmospheric chemistry impacts.
Footnotes
- ↵1To whom correspondence should be addressed. E-mail: dcaulton{at}purdue.edu.
Author contributions: P.B.S., J.P.S., R.W.H., M.O.L.C., and B.H.S. designed research; D.R.C., P.B.S., and R.L.S. performed research; D.R.C., P.B.S., R.L.S., J.P.S., R.W.H., A.R.I., K.J.D., S.A.M., and B.R.M. analyzed data; D.R.C., P.B.S., R.L.S., J.P.S., R.W.H., A.R.I., C.S., A.K., S.A.M., and B.R.M. wrote the paper; and B.H.S. designed and installed aircraft setup.
The authors declare no conflict of interest.
↵*This Direct Submission article had a prearranged editor.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1316546111/-/DCSupplemental.
Methane emission from a shale gas field
More Articles of This Classification
Physical Sciences
Environmental Sciences
Related Content
Cited by...
Similar Articles
You May Also be Interested in
Blair Hedges discusses the state of Haiti's remaining forests and the consequences to biodiversity.
A study uncovers genetic evidence of early colonization of Jamaica by primates and suggests that adaptation can shape species morphology in novel environments, even when species come from morphologically conservative families.
Image courtesy of Lorraine Meeker (American Museum of Natural History, New York).
Researchers report that some moth species use sound absorbing-scales to avoid detection by bats and suggest that the findings could aid the design of biologically inspired sound absorbers for an array of applications, including noise mitigation and building acoustics.
Image courtesy of Thomas R. Neil.
Using phylogenetic analysis, researchers report that ants used plants for food and nesting long before plants evolved structures to accommodate arthropods, and although interactions with ants likely facilitated plant diversification, plant interactions did not shape ant diversification.
Image courtesy of Pixabay/cmolens.
