I just sent the following comment to this article: http://theenergycollective.com/sierenernst/330521/quantifying-impact-multiple-avenues-methanes-underestimation . It’s my first time commenting on this site, so moderation may take a while. I thought I’d post here because I spent so much time on it, I figured it might as well appear somewhere.
There have been several recent NOAA-partnered studies showing high levels of leakage (from 4% to 9+%) in the Denver-Julesburg, Uintah, and Los Angeles basins. These were measured from atmospheric rather than surface instruments, so they would show leakage from drilling operations along with the immediate processing infrastructure. They also were able to categorize the methane associated with drilling from that from other sources, such as landfills and agriculture. http://www.nature.com/news/air-sampling-reveals-high-emissions-from-gas-field-1.9982 http://blogs.agu.org/geospace/2013/08/09/scientists-observe-significant-methane-leaks-in-a-utah-natural-gas-field/ http://www.scientificamerican.com/article/solving-the-case-of-californias-extra-machine/
We also need to consider that in some plays, such as the Bakken, methane is treated as a byproduct that isn’t worth the dollars and effort to capture, so it is flared or even vented for months on end while the companies concentrate on the much more lucrative oil. This contributes to atmospheric carbon dioxide with absolutely no beneficial use to society and currently unmeasured amounts of methane and other hydrocarbons and VOCs escaping to the atmosphere and adding to the greenhouse gas load.
There are some studies in big cities, such as Boston, New York, and Washington, that show thousands of leaks in the distribution lines, causing leakage rates up to 3%. The distribution companies who should be maintaining these lines don’t hurry to fix them because their customers are being charged for the leaked gas as part of their rates. http://www.bostonglobe.com/business/2013/07/31/gas-leaks-costing-mass-consumers/5nIv3FsJaZRwscJ48jGMsI/story.html Unfortunately, the climate comes out as a loser.
Plus, there are the thousands upon thousands of miles of pipelines and the compressor stations and other infrastructure that are venting and leaking gas, which is not being measured. Methane plumes sometimes form in areas where drilling has occurred. http://thetimes-tribune.com/news/study-airborne-methane-plume-found-near-bradford-county-gas-migration-site-1.1335347 And let’s not forget the methane emissions that are inherent in the production, storage, transport, and use of LNG.
Even if every driller used best practices with every new well going forward, there would still be much higher total leakage rates than the current EPA estimates. With so many sources of leakage, they would not be easy or cheap to fix. The comparison with coal is low-ball. Instead of comparing one fossil fuel to another, let’s compare, as the original Howarth/Ingraffea/Santoro paper does, to solar, wind, and other energy technologies. That will give us a better idea of the wisest places to concentrate our resources in the fight to keep global temperature rise below two degrees Celsius.