But some scientists are becoming increasingly concerned about methane emissions that leak from gas-drilling operations, in part because methane is a more potent greenhouse gas than carbon dioxide.
Robert Howarth, a Cornell University ecologist who authored a widely cited paper on the subject earlier this year, cautions that switching from coal to natural gas shouldn't divert the country from bringing on more renewable energy sources.
"It's not saying we should keep burning coal," Howarth said in an interview. "It's that we should do more to move to what we need to do in the longer term anyway."
Gas industry supporters, though, point to another study by researchers at Carnegie Mellon University in Pittsburgh, reporting the previous conventional wisdom that natural gas produces half the greenhouse emissions of coal.
"We favor extraction of Marcellus Shale natural gas as long as the extraction is managed to minimize adverse economic, environmental and social impacts," said Chris Hendrickson, one of the Carnegie Mellon study's authors.
The Carnegie Mellon study used different assumptions, including older estimates of methane leakage from drilling, that could account for its different results.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.