ENERGY POLICY: Shale gas isn't cleaner than coal, Cornell researchers say (04/11/2011)
Mike Soraghan, E&E reporter
Cornell University researchers say that natural gas pried from shale formations is dirtier than coal in the short term, rather than cleaner, and "comparable" in the long term.
That finding -- fiercely disputed by the gas industry -- undermines the widely stated belief that gas is twice as "clean" as coal in terms of greenhouse gas emissions. The gas industry has promoted that concept as a way for electric utilities to prepare for climate change regulations by switching from coal-fired plants to gas.
But if both gas and coal are considered plentiful and cheap, utilities would have little incentive to switch.
The lead author of the study, Robert Howarth, had previously stated the idea that shale gas production emits more greenhouse gases than coal production (ClimateWire, April 2, 2010). But now it is being published in a peer-reviewed scientific journal.
"Compared to coal, the footprint of shale gas is at least 20 percent greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years," states a pre-publication copy of the study, which is slated to be published in the journal Climatic Science and originally obtained by The Hill newspaper. [Here is the Hill item:
Howarth and his fellow Cornell professors, Renee Santoro and Anthony Ingraffea, found the process of "hydraulic fracturing," which is required to extract gas from shale, emits enough methane to make it dirtier than coal. Methane is a greenhouse gas that is more potent than carbon dioxide but does not last as long in the atmosphere.
But industry representatives disputed numerous points in the study, saying the researchers used unconventional methodologies to reach their conclusion.