...Cornell University professors will soon publish research that concludes natural gas produced with a drilling method called “hydraulic fracturing” contributes to global warming as much as coal, or even more.The results of the study depend on several things. First, as noted above, it assumes fugitive emissions of methane from fracking are higher than normal gas wells and high enough to offset the burning of coal. I don't have the data to evaluate whether that is true now or not, but I would suggest that if only in the interests of money, the companies doing the fracking will be looking at ways to prevent and capture such losses. Second, it assumes some facts about the persistence of methane in the atmosphere. Methane is not stable in the atmosphere, and oxidizes to carbon dioxide and water fairly rapidly, at least on a geologic scale. Apparently some are questioning the value of the residence time of methane in the atmosphere used in the study. The Cornell researchers used 20 years as a half life for methane in the atmosphere; the consensus numbers are more like 8. Longer residence times would result in higher concentrations in the atmosphere. There is also dispute over the potency of methane as a greenhouse gas:
The conclusion is explosive because natural gas enjoys broad political support – including White House backing – due to its domestic abundance and lower carbon dioxide emissions when burned than other fossil fuels.
Cornell Prof. Robert Howarth, however, argues that development of gas from shale rock formations produced through hydraulic fracturing – dubbed “fracking” – brings far more methane emissions than conventional gas production...
...Among Van Atten’s criticisms, the study is overstating methane’s potency as a greenhouse gas, he argues. Van Atten, in an email, notes that the paper assigns a higher global warming potential to methane than the United Nation’s Intergovernmental Panel on Climate Change. He also questions the report’s emphasis on the climatic effects of methane over a 20-year horizon.But then, Van Atten was speaking as a tool of industry:
“They focus some of their results on a 20 year period which is not particularly relevant in terms of climate change. Methane only lasts in the atmosphere for about a decade, CO2 remains in the atmosphere for about a century. By focusing on the shorter timeframe, they show a greater impact from the shorter lived chemical,” he said...
But experts from the energy consulting firm M.J. Bradley & Associates are questioning the study. “It needs to be understood as a study that has several key assumptions that are highly uncertain or based on limited data points,” said Christopher Van Atten, a senior vice president with the firm. M.J. Bradley’s client base includes gas industry clients.But then, to be fair, the Cornell reserchers are effectively tools of the Anthropogenic Global Warming community. But they do make concessions:
“We do not intend for you to accept what we reported on today as the definitive scientific study with regard to this question. It is clearly not. We have pointed out as many times as we could that we are basing this study on in some cases questionable data,” Ingraffea said at a mid-March seminar, which is available for viewing on Howarth’s website.The assumption that politicians should be deciding a "national energy strategy" offends me. It even offends me more that scientists feel it is their role to dictate to the politicians what that "national energy strategy" should be. I think the market can decide that better than a handful of smart scientists and stupid politicians.
“What we are hoping to do by this study is to stimulate the science that should have been done before, in my opinion, corporate business plans superceded national energy strategy,” he added.