The EPA gas air rule blows still more big holes in Professor Howarth's discredited 2011 study that falsely implanted in the minds of many that "gas was as dirty or dirtier than coal" for global warming pollution.
First, while Professor Howarth assumed no green completions were used during flowback, EPA documents that green completions are currently used on 50% of gas wells. This fact alone destroys Professor Howarth's false methane leakage estimates that are at the heart of his paper.
Second, the current rate of green completions apparently is higher than the EPA had assumed, when arriving at the EPA 2.4% methane leakage rate. As a result, the EPA may lower its current methane leakage rate number, even before the green completion requirement takes effect in January 2015.
Third, to his credit, Professor Howarth himself said of the then proposed EPA green completion requirement: "Can shale-gas methane emissions be reduced? Clearly, yes, and proposed EPA regulations to require capture of gas at the time of well completions are an important step."
At this point, the EPA air rule is final; 50% of wells are already green completing; 100% of wells must flare in the period prior to January 2015 (Howarth assumed zero flaring too). Those facts alone destroy the conclusions of the Howarth paper.
But, in addition, Howarth stopped his "life cycle" analysis of emissions from carbon and gas prior to the combustion of both at power plants and rejected the IPCC's 100-year global warming potential factor in his analysis.
Will all that be enough to end the use of the Howarth paper in public processes and dialogue? Unfortunately probably not.