US Emissions Of Methane Could Be 60% Higher Than EPA Estimate

According to a new study published in the journal Science, the amount of methane emitted by the oil and gas industry in the United States is up to 60% more than currently estimated by the Environmental Protection Agency.

The finding suggests that natural gas, though frequently promoted as a cleaner alternative to other fossil fuels, primarily coal, may be significantly more dirty than previously thought. Methane, after all, is a substantial greenhouse gas capable of warming the globe up to 80 times more than carbon dioxide. Methane also hangs around in the atmosphere for a long time, up to 20 years. Despite this, methane is the primary ingredient in natural gases.

Livestock is another substantial source of methane. Photo: Capri23auto via Pixabay, CC0

Methane is emitted during the production of fossil fuels like natural gas, oil and coal. Methane emissions also come from livestock, the decay of organic material, and agricultural operations, according to Amy Townsend-Small, the director of the environmental studies program at University of Cincinnati. Yet other sources of methane are lakes packed with algae sustained by fertilizer runoff, landfills, rice paddies, and even defrosting tundra.

Tracking Leaks In Methane Production States

The study published in Science found that there was conducted by the Environmental Research Fund along with the backing of 15 other institutions. The research was “the most comprehensive body of research of its kind” according to the co-author of the study Steven Hamburg.

According to the study, the EPA’s current estimate of leakage rates from oil and gas systems across the US is off by around 60%. The current EPA estimates put the leakage rate at 1.4%, yet the research found a leakage rate of around 2.3%. While the percentage of increased leaked methane seems rather small, it actually reflects the amount of natural gas needed to supply approximately 10 million homes, or about $2 billion dollars worth of lost gas.

The researchers measured the levels of leakage around natural gas wells, refineries, storage pipes underground, and storage tanks. The measurements were made in regions where production of natural gas is highest, including Colorado, Utah, North Dakota, Pennsylvania, Texas and Arkansas.

The researchers collected data by driving to various oil and gas sites over the course of five months, examining more than 100 oil and gas sites spread across 13 different states. The researchers used specialized imaging cameras capable of detecting methane that would normally be invisible. When analyzing many oil and gas sites, they found that many of the facilities were operating under abnormal states, such as natural gas spewing out form one of many condensate tanks. The researchers found the abnormal operating conditions at approximately one-fifth of all the sites that they visited during their five month investigative tour.

Reducing Leaks

A different study implies that that natural gas power plants could actually be worse for the environment than coal plants if their rate of leakage were to end up rising above 4 percent. While the new leaked rates haven’t crossed that threshold, there could nonetheless be important policy changes and ramifications that come from the new report. The report does seem to suggest that most of the resulting leakage is fixable at a relatively low cost, however.

Steven Hamburg, the author of the paper and chief scientist of the Environmental Defense Fund, explains that the emissions aren’t anything inherent to natural gas systems and are largely avoidable. Hamburg estimates that the industry could end up reducing its methane emissions by around three-quarters, with two-thirds of the reductions paying for themselves. According to the study the primary reason that leakage of methane was much higher than initial estimates is large sources, dubbed super-emitters, which add to the problem.

Photo: anita_starzycka via Pixabay, CC0

Ramon Alvarez, one of the lead authors on the study, explains that the oil and gas industries need to increase their vigilance regarding both regular, small-scale leaks and leaks from the more dramatic super emitters that are a product of the abnormal conditions found by the researchers. Alvarez says the industry will need to determine the root causes of the heightened emissions and create better systems with fewer leaks.

Yet environmental advocates argue that voluntary measures aren’t sufficient to reduce emissions, and they are putting pressure on federal regulators to step in and place more regulations on companies/mandate leakage reduction. Trump administration policies have largely rolled-back Obama-era methane leakage limits, though some of those rollbacks have met resistance in the courts. The regulation of methane leaks seems to be increasing at the state level, however. Colorado, New York, Pennsylvania and other states have announced or carried out plans to curb emissions of methane, with Colorado being the first state to tackle the problem back in 2014.

Reactions To The Study

The study was the result of almost five years of research on methane emissions with the goal of determining both the extent of methane leakage as well as methane’s effect on the climate. The Environmental Defense Fund worked with over 140 researchers from around 40 different institutions to carry out the large-scale study. The EDF and its associated researchers also received backing and cooperation from the methane industry itself.

The new measurements have received pushback from members of the oil and gas industry. Representatives of the oil and gas industry argue that in trying to account for the outliers and leaks, the study went too far in the other direction and missed the mark. Richard Meyer, the director of energy analysis for American Gas Association, says that the new estimates amount only to “speculation” and that he has serious questions about the method used by the study, along with worries that “alternative hypotheses were too readily dismissed”.

Hamburg is not swayed by these arguments and says it was fully expected that the new estimates would receive many questions. Hamburg says:

The industry is going to say it’s too high and other people will say it’s too low. You can cherry-pick either way.

The news that the emissions of methane may be greatly underestimated comes at a time when the United States is getting more and more of its energy from the use of natural gas. Last year approximately 32% of all electricity used in the US came from natural-gas powered generators, which is up from around 27% in 2013.

For its own part, the EPA says it is looking forward to the chance to review the study.

About Daniel Nelson

Daniel obtained his BS and is pursuing a Master's degree in the science of Human-Computer Interaction. He hopes to work on projects which bridge the sciences and humanities. His background in education and training is diverse including education in computer science, communication theory, psychology, and philosophy. He aims to create content that educates, persuades, entertains and inspires.

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