One of the key reasons for concern about fugitive emissions from coal seam gas is a just-published empirical study by a team of research led by Gabrielle Petron. That study directly measured methane levels in Colorado’s gas fields, and came to the conclusion that fugitive emissions were much higher than previously though.
Kathleen M. Sgamma of the Western Energy Alliance, a natural gas industry advocacy group, has responded in correspondence in Nature (NB: it is not a “letter to Nature“, which are actually short peer-reviewed scientific papers). She makes two main points in response: that practices have changed significantly since the data was collected in 2008, and that the study did not attempt to exclude the effects of methane emissions from agriculture, which are known to be considerable.
Both points appear plausible. But, at the risk of sounding like a broken record, what we need is more data, better calculation methods, and most importantly in the Australian context some local data rather than extrapolating from the US gas industry which operates in different geology and a different regulatory environment!