Last week we reported on a paper led by researchers at the National Oceanographic and Atmospheric Administration (NOAA) and the University of Colorado that raised troubling questions about methane emissions from a gas field north of Denver, pictured at right. The paper relied on field measurements and as well as an analysis of the various hydrocarbon constituents found in those measurements in order to arrive at an estimate of methane leakage from natural-gas production in the area. Now some of the basic assumptions in that paper are being questioned by Michael Levi at the Council on Foreign Relations.
In a blog post this week, Levi targets assumptions about the composition of the gas being leaked and where it is coming from (wells that produce primarily natural gas — methane — or those that produce liquids such as propane and butane). He also questions the way the authors arrived at their conclusion as well as what this paper might or might not say about methane leakage from natural-gas operations elsewhere, particularly as described in a controversial study by researchers at Cornell University last year.
Levi credits the paper with providing “fantastic observational data” that can be used to shed light on these questions. “For now, though, I’m not ready to rely on its results,” he says.
Gabrielle Pétron, a scientist at NOAA and the university and the first author on the study, defended the analysis and said that she and her co-authors continue to work on ways to reduce uncertainties. She welcomed Levi’s promise to follow up with his own analysis in a formal comment to the Journal of Geophysical Research.
So keep an eye out. There’s more to come.