Fugitive methane emissions from Los Angeles basin oil and gas drilling operations at 17%!

EMISSIONS: Solving the case of Southern Calif.'s missing methane

by Stephanie Paige Ogburn, E&E reporter, E&E, May 15, 2013 May 15, 2013

In Southern California, scientists knew the missing methane had to be coming from somewhere. Was it dairies? Landfills? Natural seeps? Oil and gas operations?

Emissions of methane from the Los Angeles basin had been estimated in the mid-2000s as part of the state's landmark cap-and-trade bill, known as A.B. 32, which regulates emissions of the powerful greenhouse gas. But later measurements of the air in the region showed there was a lot more methane being emitted than was accounted for, more than a third as much.

Where was this "missing" methane coming from? Methane has 20 times the global warming potency of CO2. If regulators could identify the source, they could also get those methane emitters to reduce the amount of the gas they release.

NOAA’s P-3 sniffs Los Angeles air to solve a mystery. Photo courtesy of NOAA.

Now, Jeff Peischl, an associate scientist at the National Oceanic and Atmospheric Administration's Cooperative Institute for Research in Environmental Sciences, has solved this puzzle, outlining the sources of the missing methane in a paper published yesterday in the Journal of Geophysical Research.

While methane in the Los Angeles basin comes from many sources, there are three main sectors responsible for the difference in what the state of California had estimated and what is actually being emitted.

These are leaks from pipeline distribution systems, natural seeps from areas such as the La Brea Tar Pits and emissions from oil and gas drilling operations in the area.

Peischl was able to determine where the methane came from because different sources of methane contain different ratios of compounds called alkanes, like propane and butane.

By examining the ratios of alkanes in samples collected from 16 overflights of the Los Angeles basin in 2010, using NOAA's P-3 aircraft, a flying laboratory with sensitive air-sampling equipment, Peischl learned whether methane came from a landfill, dairy or fossil fuel source.

Leaking money

In his analysis, Peischl found that the methane leak rate from Los Angeles-area oil and gas operations was 17%. This is high; leakage rates of "fugitive emissions" from oil and gas drilling operations are currently estimated at 4% by U.S. EPA (ClimateWire, April 4, 2013).

The California Air Resources Board has been working toward pinning down this leakage percentage in its own way, too. Peischl's paper cites a survey it did of oil and gas producers in which it queried them about the equipment they use. Based on those results, CARB's revised estimate for fugitive emissions from the Los Angeles basin is 12%.

While this new figure is not yet incorporated into the state's greenhouse gas inventory, Peischl was encouraged that his calculated emissions and the board's were in the same ballpark, even though they used an entirely different methodology.

Paul Wennberg, a scientist at the California Institute of Technology who did two of the previous studies in the region that showed methane emissions were much higher than the earlier inventory, was encouraged by Peischl's results. He pointed out that if the missing methane was from fossil fuel extraction, this could be a "win-win" situation. Methane, or natural gas, is valuable. Oil and gas producers would certainly benefit from reducing their leakage.

"This is an important finding that we need to follow further," Wennberg wrote in an email.

CARB is doing just that. According to Bart Croes, chief of the agency's research division, Peischl had presented his work to the agency at an earlier date, and it is continuing research in this vein.

Peischl's results were surprising, Croes said, because many people thought dairies and landfills were likely sources for the mystery methane. "There was this suspicion that they could be a major contributor, but they don't seem to be," he said.

Now that it knows the sources, the board is working to determine where exactly that methane is coming from. Staff members are driving electric vehicles equipped with sensors to measure methane leaks around Southern California and implementing a network of stationary methane monitors.

The California Energy Commission is also doing a study of homes to try to determine where residential methane leaks from the natural gas pipeline system might be occurring, Croes said.

"Once we understand what the methane emissions are, then we'll explore, through our research, options to control these emissions or reduce them somehow," he added.

Paywalled:  http://www.eenews.net/climatewire/2013/05/15/stories/1059981192

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Angry Bear: Updates on atmospheric methane and volume measurements of Arctic sea ice

by Dan Crawford (Rdan), Angry Bear blog, February 18, 2013

Here is a link-filled update on the rise of atmospheric methane and a decrease in volume of Arctic sea ice from reader rjs.

Today we’d like to make note of an interesting development in the arctic     during January. Below we have 3 images of methane concentrations above the Arctic Ocean from 3 ten day periods in january (January 1-10, January 11-20, and January 21-31, 2013) from Russian physicist Dr. Leonid Yurganov. The methane concentration scale, with darker reds being the highest, can be viewed by clicking on the image to enlarge it.



Quite obviously, there's been a sudden increase in atmospheric methane in an area of the arctic ocean north of eastern Europe and western Asia. As shown in the post about this at Arctic News, that area where the methane concentrations are highest coincides with the area of the arctic ocean that is still relatively ice-free. 

This dramatic increase in atmospheric methane seems to be similar to an arctic event that we covered a little over a year ago that occurred in November 2011. At that time Russian scientists [Shakhova & Semiletov] had observed vast plumes of methane bubbling to the surface of the arctic ocean off the coast of eastern Siberia [and again, even more pervasive, in late 2012], which they described as "powerful and impressive seeping structures more than 1,000 metres in diameter."

Back then we figured that since that eastern Siberian area was one of the shallowest areas of the arctic, it had warmed enough during a period of unusual atmospheric circulation that fall to thaw the extensive amounts of frozen methane hydrates known to be locked up by high pressure and cold temperatures on the ocean floor, and they were melting and rising to the surface. In this case it appears that a branch of the warm gulf stream current is causing enough warming to destabilize the frozen methane on the ocean floor in the areas between Norway and Svalbard and points east. This is similar to a scenario that was warned about in a study in the journal Nature in October.

What happens next is anyone's guess, but Dr Yurganov's records indicate that higher levels of arctic methane emissions have been increasing over time. (US scientists must now rely on Canadian and European monitoring of greenhouse gas emissions because NOAA’s monitoring of Arctic methane and CO2 was halted last week by budget cuts.) We've pointed out before that atmospheric methane hit a new high of about 1,813 parts per billion (ppb) in 2011, which was at 259% of the pre-industrial level, and that 40% of the increase was coming from natural sources such as this. 

Methane is 25 times as potent a heat-trapping gas as CO2 over a 100-year time horizon, but 72 times as potent over 20 years, and methane's global heat trapping effect is now roughly one-third that of CO2. Further thoughts on the potential impact of large abrupt release of methane in the Arctic are here. Suffice it to say that if all the ancient carbon were to be released from the arctic it would be enough to raise global temperatures 3 C on top of the 4 C temperature rise from human activities predicted by the recent World Bank study…

Our awareness of this comes the same week that the European Space Agency’s CryoSat-2 probe has confirmed the conclusion of the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the University of Washington’s Polar Science Center that not only is the extent of the Arctic ice receding, but its thickness has diminished considerably as well. The combined result has been a collapse in total arctic ice volume to one-fifth of what was the minimum ice volume as recently as 1980. With the associated warming in the Arctic, we can only expect the frequency and range of such Arctic methane releases to increase, from both the seabed and the permafrost.

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