At the end of last year I examined assertions by a professor from Cornell University, based on his unpublished paper, that leakage from natural gas production and transportation systems in the US resulted in lifecycle emissions for gas that were actually worse than those from coal. From what I saw at the time, I couldn't agree with his conclusions. Now Professor Howarth's paper is apparently about to be published, with a specific focus on shale gas. It has already been leaked via the New York Times and The Hill news site. After seeing the data and calculations supporting its claims, I am still not persuaded, though I would be quick to concede that the subject deserves a more thorough assessment by a body actually equipped to gather the necessary data and process it rigorously.
I don't make a habit of reviewing scientific papers, but this one begs for a critique, for two reasons. First, it's appearing in the middle of a crucial national debate on the potential risks of the techniques involved in unlocking the potentially game-changing shale gas resources that have been found in the US and elsewhere around the world. What better way to make those risks--which I believe to be entirely manageable--seem not worth taking than by portraying shale gas as having more adverse environmental consequences than the chief fuel its supporters see it displacing: coal. So at a minimum the paper demands careful scrutiny because of its potential significance to the debate surrounding the largest energy opportunity the US has uncovered in decades.