If you weren’t paying close attention, you probably missed the release
of an MIT study addressing methane emissions and shale gas development.
The study (“Shale gas production: potential versus actual greenhouse gas emissions”) analyzes emissions data from each of the horizontal
shale gas wells developed in the United States during 2010. It finds
that total methane emissions amounted to 216 gigagrams, which is in
stark contrast to previous – and exaggerated - estimates of about 900
Why is this difference important? Some scientists, including Cornell's Robert Howarth, have used the exaggerated numbers to inflate the estimate for lifecycle greenhouse gas emissions from shale gas development. Francis O’Sullivan and Sergey Paltsev, the authors of this MIT study, point out “it is incorrect to suggest that shale gas-related hydraulic fracturing has substantially altered the overall GHG intensity of natural gas production.” In other words, claims that natural gas produces more greenhouse gas emissions than coal are flat wrong.
How did MIT’s scientists arrive at this lower emissions number? The answer has to do with how fugitive emissions, which is natural gas emitted into the atmosphere that a producer could otherwise sell, are treated. O’Sullivan and Paltsev showed that natural gas producers were capturing much of what would have been fugitive gas, as part of broad methane emissions control measures. This is a valid assumption because it makes economical sense for companies to bear the cost of reducing emissions than to allow so much of their product to go to waste, the study concludes.
The environmental benefits from using natural gas to generate electricity have long been clear. In fact, the EIA recently reported that U.S. energy sector-related CO2 emissions during Q1 of 2012 were at their lowest level in twenty years - an environmental milestone that resulted in part from natural gas use. MIT’s study confirms that natural gas – from well head to power plant –is providing a lower-emissions energy alternative.