Published on July 27th, 2014 | by Sandy Dechert1
Scientific American Raises The Methane Issue: Coal vs. Natural Gas?
Opponents of natural gas fracking on environmental grounds (groundwater pollution, seismicity, and socioeconomic disruption, to name a few) have a much stronger argument against the practice since the publication of two methane studies in scientific journals and a lay summary in Scientific American last week.
Stefan Schwietzke, a researcher at the National Oceanic and Atmospheric Administration’s Earth Systems Research Laboratory in Boulder, Colorado, led both the scientific studies. His team of researchers recalculated previous inventories from the Environmental Protection Agency, the intergovernmental climate panel, and other sources to pin down oilfield and coal emissions with more certainty. They then put the results through a custom atmospheric computer model.
The results were published last week in two respected and peer-reviewed scientific journals: Environmental Science & Technology and Sustainable Chemistry and Engineering. (See study methodology at right.) The findings are not the first on the subject, but they do put another nail in the coffin of our headlong rush to natural gas. [As reported last year by Scientific American and ClimateWire, David Allen, a University of Texas researcher, found higher than expected levels of methane, as did Robert Howarth, a researcher at Cornell. In the journal Proceedings of the National Academy of Sciences last year, Scot Miller, a Harvard atmospheric scientist, found that both the EPA and the European-based Emissions Database for Global Atmospheric Research (EDGAR) had underestimated methane production. His team also linked higher levels of methane emissions in Texas, Oklahoma, and Kansas with petroleum drilling.]
Of course, the oil and gas industry and its regulators have known for a long time about the potential for fugitive emissions (leaks at the drilling site and through pipelines and processing infrastructure). It took until the wholesale application of fracking to shale reserves for anyone to carefully measure them, and budget cuts have complicated the process: according to one report, the US needs three times as many towers and observations as we now possess. And measurements aren’t easy, because natural gas, oil, and coal extraction release similar byproducts, although in different quantities.
What Schwietzke’s new investigations revealed was potential leakage rates between two and four percent of the gas produced in five years studied (2006-2011), spiking at nearly 10% in the Uinta basin of Utah. Carbon dioxide emissions from burning fossil fuels in a plant have a longer-term effect. Methane leaks from wellheads, pipes, valves, compressors and various other equipment whack the atmosphere like shots of an energy drink, up to 86 times as strongly as straight CO2 emissions over a 20-year time period.
A three percent level is enough to negate the climate benefits of gas over coal during the next two decades. It puts natural gas emissions at a climate equivalent of coal impacts, so the 2-4% findings are enough to call into question the ultimate wisdom of burning natural gas for power versus burning coal.
EPA’s latest estimate of fugitive methane emissions, prepared mostly on the advice of petroleum company scientists, was 1.2% (equal to the annual emissions of 112 million cars). “The natural gas industry says its emissions are close to zero,” Scientific American reports. “It also maintains that regulations are unnecessary to cut down on leaks, as companies have an economic incentive to capture methane.”
As usual, industry spokespeople respond by touting their leading role in “developing new technologies and equipment” to combat the problem. (Rhetorically: what does anyone else have to gain from doing it, who else has access, and who determines whether the technologies and equipment are adequate to solve the problems?)
It’s also interesting to know that as the Carbon Disclosure Project found, and we reported in our sister publication CleanTechnica earlier this month, American utilities have begun including carbon emissions in their costs of doing business. Another interesting development: in mid-May, Royal Dutch Shell issued a public letter in response to shareholder questions about carbon risk and oil company capital expenditures. Underestimated and unmitigated fugutive emissions certainly qualify as good reasons for investors to fear stranded assets.
There’s one more thing—the new research suggests that some of the oil and gas fields in the US, like the Uinta, are emitting more methane than those in the rest of the world. A possible reason, the methane authors say: sloppy drilling and processing. Gayathri Vaidyanathan of SciAm and ClimateWire, who produced the summary article in SciAm, get right to the point about the possible political implications:
“The insights go to the heart of the debate surrounding the use of natural gas in the United States today. The nation is in an oil and gas boom due to technological advances that have unlocked vast new reserves and vaulted the nation beyond energy behemoths like Russia and Saudi Arabia.”
Since 2009, the Obama administration has enthusiastically supported natural gas as a “transitional” or “bridge” fuel to a post-carbon future because it emits about half as much carbon dioxide from the power plant as coal. Many view fuel-switching as a good way to slow climate change. In fact, this year’s Fifth Assessment of the Intergovernmental Panel on Climate Change has found robust evidence and high agreement on the issue:
“GHG emissions from energy supply can be reduced significantly by replacing current world average coal‐fired power plants with modern, highly efficient natural gas combined‐cycle power plants or combined heat and power plants, provided that natural gas is available and the fugitive emissions associated with extraction and supply are low or mitigated.”
It’s the fugitive emissions that make the difference.
Some reports, like Jack Smith’s piece yesterday in Global Research, call the President an outright liar on natural gas. It’s interesting to note that Mr. Obama’s verbiage about the relative values of gas and coal has clearly moderated since the most recent National Climate Assessment—whether through enlightenment or by design. Smith’s subtitle “Obama Supports Massive Expansion of Hydraulic Fracturing” is misleading in this respect and has little relevance to Obama’s recent Atlantic drilling decision, as Smith asserts.
In The New York Times, leading environment reporter Justin Gillis recently discussed natural gas vs. coal as picking the lesser of two climate evils. He brings up a thought from Raymond T. Pierrehumbert, a climate scientist at the University of Chicago, that we may be trying to weigh impacts of greenhouse gases over the next 20 years against those of coming millennia. Gillis offers a third possibility:
“What is the chance that a two-pronged attack on climate change would increase the overall level of political will? The idea would be to promise far more aggressive methane control to slow global warming for the benefit of people alive today, along with aggressive CO2 control for the benefit of future generations.”
Seeing the two methane studies published widely in the nation’s most reputable lay science journal offers a ray of hope for public awareness in the United States. The reports now appear online and should repeat in other science publications and stimulate debate. And who knows? They may even make the evening news—probably from Diane Sawyer or Brian Williams rather than CNN, and almost certainly not from Fox.