Shale gas as polluting as coal and oil? Be serious!

18.04.2011

A study conducted by Professor Robert Howarth of Cornell University in New York State tries to demonstrate that shale gas generates as much greenhouse gas (GHG) emissions as coal, oil, or conventional gas.

Unfortunately, this study is based on a false premise, as the author does not use generally accepted parameters, including by the United Nations, to determine global warming potential (GWP). This comparison index quantifies the marginal contribution of GHGs to global warming, compared to that of carbon dioxide (CO2).

The author of the study draws conclusions based on analysis of the effect of methane over 20 years, while recognized scientific experts believe that assessments should rather be determined over a 100 year horizon. In addition, the author and his team recognize having used preliminary data that are incomplete and whose reliability could be questionable.

The latter also commit the sin of oversimplification in asserting that between 3.6 and 7.9% of total well production escapes into the atmosphere. To arrive at this figure, they subtract the volume of gas delivered from the volume of gas produced and argue that the difference is a loss. However, this conclusion is wrong because it ignores certain known practices, for example: 1) some gases are liquefied (butane, propane) and sold separately; and 2) some compressors along a pipeline are connected directly to the latter due to the lack of electrical power sources.