California leak was top methane release in US history

“At its peak this blowout effectively doubled the CH4 [methane] emission rate of the entire Los Angeles Basin, and in total released 97,100 metric tonnes of methane to the atmosphere”, they wrote.

“Our results show how failures of natural gas infrastructure can significantly impact greenhouse gas control efforts”, said NOAA’s Tom Ryerson, a lead author of the study, who pioneered air sampling data collection during the 2010 Deepwater Horizon oil spill.

Aliso Canyon is an extreme case, but methane leaks are frighteningly common, and they take a significant toll for the environment.

The 2004 collapse of an underground gas storage facility in Texas actually expelled more natural gas, but it was mostly consumed in an explosion and fire, so the methane never reached the atmosphere, the study said. The natural gas reservoirs were originally oil-producing wells erected in 1954 which were then repurposed after they had been emptied; they now store natural gas during periods of low demand.

Here some of us are deciding to ride our bikes in winter and giving up cars altogether in order to be easy on the planet – only to learn that a single natural gas leak will have an impact on the climate equivalent to annual greenhouse gas emissions from over half a million cars, according to a new study.

The company says it had already proposed an extensive series of inspections and repairs for its underground gas fields in the 2014 request for a rate increase. The leak caused schools to close and uprooted some 6,400 families, many of whom “complained of headaches, nausea, nosebleeds and other symptoms as an intermittent stench wafted through the area”, according to The Associated Press. SoCal Gas was ordered to temporarily relocate residents at its own cost.

Methane, the main component of natural gas, is only in the air around our earth for about 12 years.

The scale of the leak, and the attention it attracted, was unusually dramatic. Conley was referring to the location where the methane leak occurred.

Storm clouds hang over the Porter Ranch neighborhood, near the Aliso County, California, gas leak, December 22, 2015.

“The methane releases were extraordinarily high, the highest we’ve seen, ‘ confirms Donald Blake, atmospheric chemist at the University of California-Irvine”.

“Before we went, no one had any idea the magnitude of it”, Conley said.

In addition, lawsuits have been filed against SoCalGas by Los Angeles officials and among residents who said the leak has caused them illness, lost time at work, and other inconveniences. Another study published this week in the journal Geophysical Research: Atmospheres identified more than 200 hotspots for methane leaks throughout the Los Angeles region, just miles from the Porter Ranch blowout.

Almost four months after it started, the Porter Ranch gas leak has been stopped.

Throughout the leak plugging process, the researchers found that “exceptionally high concentrations” of methane and ethane settled into the nearby San Fernando Valley area.

The next largest source of methane in the United States is an Alabama coal mine, researchers said. “We also need to reduce non-CO2 greenhouse gases to lessen the likelihood of us crossing this climatic threshold”.