Intelligencer Journal/Lancaster New Era
Natural gas leaks raise climate concern
BY JULIET EILPERIN, The Washington Post
WASHINGTON -- Two guys in a black Pontiac Vibe cruise the streets of Washington's residential neighborhoods. The only sign of what they are up to is a gray plastic tube hanging out of the trunk. And the fact that they get out of the car frequently to place a black box on manhole covers and study its readings.
Measuring how much methane gas is leaking from pipes under the District of Columbia could help answer a key policy question. As natural gas production expands in the United States, do its benefits for the climate far outweigh its dangers?
Methane, the main component of natural gas, is about 25 times more powerful as a heat-trapping gas than carbon dioxide, the largest human contributor to climate change; the atmospheric concentration of methane has doubled since the start of the Industrial Revolution.
While it largely dissipates in a few decades and there is far less of it in the atmosphere than CO2, it continues to drive global warming. Depending on how much leaks out in the journey from wellhead to homes and factories, some experts say, it could be enough to offset the advantages natural gas has over coal.
"We don't have enough data to develop sound policy going forward," said Steven Hamburg, chief scientist of the advocacy group Environmental Defense Fund. He noted that natural gas has a complex supply chain with "different geographies and geologies" along the way.
Hamburg is spearheading a $10 million, two-year effort to measure methane emissions along the nation's supply chain. As activists and energy executives debate the natural gas industry's impact and the Environmental Protection Agency weighs whether to impose new regulations, Hamburg said, "it's critically important" the country develops a better data set on methane leaks.
The group has brought together academics, environmentalists and industry representatives to track different stages of natural gas extraction, production and transmission and will issue its initial report in May.
Last fall, a team from Duke University's Nicholas School of the Environment, published the results of a survey of Boston that showed the city's aging infrastructure had 3,356 leaks.
Researchers disagree about how much methane is leaking into the atmosphere.
Cornell University's Robert Howarth has estimated somewhere between 3.6 percent and 7.9 percent of methane escapes during the production life cycle of shale gas; the Massachusetts Institute of Technology countered with a study saying it is just a fraction of that amount.
University of Colorado research scientist Gabrielle Petron, who also works in the National Oceanic and Atmospheric Administration's global monitoring division, said the rate of increasing atmospheric methane concentrations has accelerated tenfold since 2007. She said it will take a few more years to determine whether the natural gas boom helps explain the change.
"All we've done now are snapshot measurements," she said.
Their findings have major safety and environmental implications. Gas leaks contribute to smog and can lead to explosions and fires, including one that leveled a Kansas City, Mo., restaurant Feb. 19, or the 2010 San Bruno, Calif., pipeline explosion that killed more than half a dozen people.
And leaking gas also can weaken and kill trees in urban areas by replacing oxygen in their roots and drying them out; Ackley has helped organize a lawsuit by five communities surrounding Boston against the region's gas company, National Grid, and he is consulting with Montgomery County, Md., residents concerned about tree deaths there.
National Grid spokesman David Graves said that while his company has addressed individual tree deaths, "There is no evidence to support the claim that underground gas leaks cause widespread damage in vegetation."