North Texas Methane Study Confirms Environmental Benefits of Natural Gas
Monday, December 07, 2015
Methane leakage rates in the Barnett Shale are below the threshold at which scientists believe natural gas could lose its environmental advantages, according to a new study published by the Proceedings of the National Academy of Sciences. The research was backed by the Environmental Defense Fund (EDF).
The study, which sampled air emissions from several parts of the Barnett Shale region of North Texas, showed a methane leakage rate of about 1.5 percent. That’s about half of the 3.2 percent leakage threshold that EDF and other scientists have determined could result in natural gas losing its environmental advantages, particularly with respect to greenhouse gas emissions and climate change.
According to the study:
“The measured Barnett methane leakage is low enough that gas fired electricity in this region causes less climate forcing than coal-fired electricity…” (p. 3)
The U.S. Environmental Protection Agency (EPA) has previously estimated the methane leakage rate for shale gas development is about 1.5 percent. Several other peer-reviewed studies in recent years, most of which were also supported by EDF, have similarly showed a low overall leakage rate.
Although the study mentions the low overall leakage rate, it attempts to place more emphasis on the small number of sites that account for most of the methane emissions. “Two percent of oil and gas facilities in the Barnett accounts for half of methane emissions at any given time,” according to the study’s authors, who added that “10% are responsible for 90% of emissions.”
The focus is not surprising, since EDF has previously focused on so-called “super-emitters,” or a small number of sites that may have higher than average methane leakage rates. EDF contends that these comparatively few emitters justify costly new regulations from the EPA to clamp down on emissions nationwide.
EDF’s methane research has spanned several years, and one of the first major studies that it had financially backed – published by the Proceedings of the National Academy of Sciences in 2013 – similarly showed a low overall leakage rate.
Nonetheless, earlier this year, EPA pushed forward with new methane rules. Just weeks after announcing the regulations, EPA released new data showing that emissions from oil and natural gas systems have fallen by about 13 percent since 2011.
A previous North Texans for Natural Gas analysis showed how EPA’s methane rules are a solution in search of a problem. Methane emissions from oil and natural gas production only represent about one percent of all greenhouse gas (GHG) emissions in the United States.
The EDF-led study also refutes a common claim from anti-fracking groups, namely that methane leaks from shale gas cancel out its environmental benefits. Activists have frequently cited discredited research from Cornell University, which suggested methane leakage from shale gas could be over seven percent.
Dr. Steven Chu, a former Nobel Prize-winning physicist and President Obama’s first Secretary of the U.S. Department of Energy, previously said of the Cornell research: “we didn’t think it was credible.”
Notably, even some environmental groups have suggested that methane leakage is a “minor factor,” and that the impacts have been “overstated.” The U.N. Intergovernmental Panel on Climate Change (IPCC) has also credited fracking “for a reduction of GHG emissions in the United States.”