Posts Tagged ‘greenhouse gas emissions’
Shale Gas Worse Than Coal Study Finds
By Stephen Leahy
UXBRIDGE, Canada, Jan 24, 2012 (IPS)
Hundreds of thousands of shale gas wells are being “fracked” in the United States and Canada, allowing large amounts of methane, a highly potent greenhouse gas, to escape into the atmosphere, new studies have shown.
Shale gas production results in 40 to 60 percent more global warming emissions than conventional gas, said Robert Howarth of Cornell University in New York State.
“Shale gas also has a larger greenhouse gas footprint than oil or coal over the short term,” said Howarth, co-author of a study called “Venting and Leaking of Methane from Shale Gas Development” to be published in the journal Climatic Change.
This latest study follows up on Howarth and colleagues’ controversial April 2011 paper that provided the first comprehensive analysis of greenhouse gas emissions from shale gas obtained by hydraulic fracturing. That study found that when gas wells are “fracked”, they leak large amounts of methane and pose a significant threat to the global climate.
“We stand by the conclusion of our 2011 research,” said Howarth.
That research undercuts the logic of energy sector claims that shale gas is a “bridge” to a low-carbon energy future. Those claims are based on the fact that natural gas (which is mainly methane) has half the carbon content of coal, and when burned for electricity it is more energy efficient than coal.
However, those climate gains are more than negated by methane leaks both at the well during the fracking process (called flow-back), and through the gas delivery and distribution system. Howarth and colleagues estimate that between 3.6 and 7.9 percent of all shale gas produced leaks – called “fugitive emissions” – into the atmosphere, making it worse than burning coal or oil. Read the rest of this entry »