Earlier last year we posted a blog on whether the new natural gas boom, thanks to improved drilling technologies and hydraulic fracturing or “fracking”, was to be considered a boon or bane to Earth’s climate. The boon part comes from the fact that natural gas burns much cleaner and causes roughly a factor of two lower CO2 emissions than the burning of coal. So if the gas were exclusively used in high efficiency gas-fired power plants, or even combined heat and power (CHP) plants to replace coal combustion power plants for electricity production, CO2 emissions reduction would be maximized. The bane part is the fact that mining and use of natural gas does not happen without the inevitable gas leaks, in this case releasing a different, more powerful greenhouse gas: methane.
We concluded that knowledge on leak rates (commonly expressed as a percentage of produced gas), especially for newly developed wells and their infrastructure, was lacking. Some scientific estimates implied rates near or below 2%, while others implied 5% or more. We also pointed out that, regardless of current leak rates from booming oil&gas activities, methane leakage in general is an important issue.
The methane budget
Several recent scientific assessments put current fossil fuel related, “fugitive” methane emissions to the atmosphere at 100 million tons per year, roughly two thirds coming from the oil&gas industry, the remaining third from coal mining. It is useful in this context to realize that humans have roughly tripled the emissions of methane to the atmospheresince the beginning of the industrial revolution. Meaning, nature only provides for one third of atmospheric methane, the other two thirds are from human activities, dominated by domestic ruminants (mostly cows, i.e. the beef you eat) and fossil fuel mining and use. At the same time, nature takes care of all methane removal from the atmosphere, overwhelmingly through its slow atmospheric photo-oxidation. This oxidation is responsible for an atmospheric lifetime of methane of nine years and causes a ripple effect through atmospheric chemistry, such as via producing ozone and carbon monoxide, and via increasing the lifetime of other trace gases, including methane itself.
Inventoring human emissions
Because methane is such a strong greenhouse gas, reducing its emissions has direct benefits for climate stabilization. Methane’s comparatively short atmospheric lifetimewould make the effects of emissions reductions measurable in the atmosphere within a decade. Alas, neither the production of beef nor the mining and use of fossil fuels are on the decline. Nevertheless, much ado has been made of EPA’s 2013 US greenhouse gasinventory, in which the agency lowered its estimates of past oil&gas industry related methane emissions to below 2% of produced gas amounts. This change has been misused by “pro-fracking” advocates to again attack the initial Howarth work and argue that methane releases are much lower than presumed, while “anti-fracking” advocates have instead highlighted that methane still contitutes a large fraction of US greenhouse gas emissions.
That was a good summary article from SkS. Here is some more info I have been compiling recently on fugitive emissions of methane. The first ever ‘Science Paper’ published on the GHG Footprint of Unconventional Gas extraction was not until March, 2011 by Howarth (as mentioned above). A decade after the shale gas boom began. Methane and the greenhouse-gas footprint of natural gas from shale formations by Robert W. Howarth, Renee Santoro, Anthony Ingraffea about the USA. This paper received a lot of criticism as it didn’t actually perform direct measurements but analysed various prior Papers and assumptions. It was… Read more »
DRINKING WATER Contamination Studies June 2013 – Increased stray gas abundance in a subset of drinking water wells near Marcellus shale gas extraction by Robert B. Jackson et al Edited by Susan E. Trumbore, Max Planck Institute for Biogeochemistry, Jena, Germany, and approved June 3, 2013 http://www.pnas.org/content/110/28/11250 Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing Center on Global Change, Nicholas School of the Environment, Division of Earth and Ocean Sciences, Nicholas School of the Environment, and Biology Department, Duke University, Durham, NC 27708 Edited* by William H. Schlesinger, Cary Institute of Ecosystem Studies, Millbrook, NY, and approved… Read more »
This took from 2007 until 2013 to obtain a definitive ‘public’ science based answer about a fracking chemical release? Hydraulic Fracturing Fluids Likely Harmed Threatened Kentucky Fish Species – Released: 8/28/2013 Hydraulic fracturing fluids are believed to be the cause of the widespread death or distress of aquatic species in Kentucky’s Acorn Fork, after spilling from nearby natural gas well sites. These findings are the result of a joint study by the U.S. Geological Survey and the U.S. Fish and Wildlife Service. The Acorn Fork, a small Appalachian creek, is habitat for the federally threatened Blackside dace, a small colorful… Read more »
New 2013 Laws, Regulation, Environmental Protections for Coal Seam Gas (Fracking) NSW Australia Information from the NSW State Government website about the outcomes of this review. It is one example of how protesting and environmental activism made some gains in the Regulatory and Protection systems. COAL SEAM GAS PROTECTIONS Protecting our environment, the land, water resources and local communities is a key focus of the NSW Government’s Coal Seam Gas (CSG) regulatory framework. Exploration and production across the State is now subject to some of the strictest controls in Australia. http://www.csg.nsw.gov.au/protections#.UtYPCvQW3h5 Videos http://www.csg.nsw.gov.au/videos#.UtYG1vQW3h4 DOC Title: NSW Code of Practice for… Read more »