-Fracking and methane leakage: the latest study-
19 researchers from the NOAA and CIRES received the green light for a study that will soon be published in Geophysical Research, and which suggests – rather grimly – that national methane gas emissions might be a lot higher than the EPA’s 2011 estimates. Methane gas leakage from fracking operations is, according to FrackWire’s research, one of the realistic concerns associated with the extraction practice. Atmospheric methane levels fell between 1996 and 2006 but are on the rise again as the US makes the gradual switch from coal to gas. What does this mean?
“We’re estimating that 9 percent of that is just leaking right out, never getting to the end of the pipeline . . . to the actual user point,” Colm Sweeney, a coauthor of the study and a scientist with CIRES at the University of Colorado Boulder.
It’s not the consumption of natural gas for electricity or heating that worries scientists. Rather, national methane leakage rates from production, extraction, and transport are at issue. Basically, a sample was taken from the Uintah natural gas field in Utah, where 4,800 natural gas wells and 1,000 oil wells are distributed. Using aircrafts to sample downwind currents from oil & gas wells, researchers were stunned to find a 9% methane leakage rate in the region. Keep in mind that the national gas industry must keep its methane leakage rate below 2% if it is to be emissions-competitive with coal and if it is to uphold its claim to producing the more “climate beneficial” fossil fuel. While this study is limited to one gas field and one day’s sample, if rates are similar elsewhere and in other states, it would be a blow to the natural gas industry. After-all, the justification for the unconventional extraction process lies primarily on its claim to being cheap and less harmful to the climate. But in accord with our previous posts on the topic, there may be little reason to worry if regulations ensure that well and pipeline construction and sealing are such that leaks can be successfully curtailed.
Does the fall of CO2 necessitate the rise of CH4? Cornell climate scientists estimate that half of the current methane emission increase is derived solely from the natural gas industry and that these emissions are actually 25 times more powerful than carbon dioxide in warming the climate. But the EPA’s estimate of national methane gas leakage rate from the combined activities of drilling, processing, shipping, and burning of natural gas amounts only to 1.5%. These lowered estimates were based off the increasingly widespread practice of “green completion”, whereby more companies have been adopting better procedures for properly sealing wells after extraction. And according to climate scientist Raymond Pierrehumbert, the climate effects of methane emissions, while powerful, tend to decline after 20 years whereas CO2 emissions are irreversible.
This latest team of researchers believe that the actual national figure for methane leakage rate may lie between 6.2 and 11.7%, though they’ve tested only one natural gas production zone so far. There are now efforts being made to replicate the study in other drilling zones – Texas, Pennsylvania, and Colorado specifically. But this will be difficult to repeat in peri-urban areas where more pollution from other sources will need to be distinguished from methane leakage to accurately determine regional rates.
Climatologists, as evidenced above, are clearly split on the issue, making the gravity of methane leakage difficult to determine. Some warn that not only has the EPA made too lightly of methane emissions, but that the warming potential of the methane molecule may also be underestimated and understudied. Nevertheless, in 2011, methane accounted for only 8.8% of total U.S emissions - methane leakage representing only 2% of that fraction – assuming the EPA’s methodology is solid. But governmental and intergovernmental agencies recognize separate claims, too. The UNEP (UN Environmental Programme) reviewed the study from Boulder and openly confirmed that emissions from fracking gas leaks and flares could actually boost global warming initially and would really only begin to offset coal in over a century.
How do we interpret conflicting reports about methane leakage rates and their global warming potential relative to coal? Recall that methane emissions come not only from leaking pipelines and wells, but from Arctic lakes no longer topped with permafrost and from gas flares at drilling sites that burn the methane off as CO2. Between 2011 (when the EPA released its study) and now, thousands of wells have been drilled and fracked. Where we’re concerned, there clearly needs to be more on-site and state-by-state studies conducted to determine accurate rates of methane leakage. If researchers from NOAA and CIRES are correct, serious changes need to be made in the natural gas industry. In fact, it may be equally revealing to publish reports that compare companies and thus pressure for better extraction methods, sealing practices, and materials that won’t deteriorate 50-100 years from now. Policy decisions, in the meantime, seem to draw from disparate reports. Many governments have decided making the switch from coal to gas is necessary even while contradictory studies on the effects of unconventional energy extraction render the benefits of the transition dubious.